Lauro, Ortega, and Carpinteria reservoirs receive water from the conduit and were specifically constructed for this purpose. In contrast, the 135-ft tall Glen Annie Dam was originally constructed to impound water from the West Fork of Glen Annie Creek to irrigate agricultural fields along Glen Annie Road6
. Although Glen Annie Reservoir continues to capture and store natural discharge from West Fork Glen Annie Creek, its only purpose under the proposed action is to capture water drained from the conduit during periodic inspection and maintenance. The
5 South Coast Member Units are comprised of Goleta Water District, City of Santa Barbara Water District, Montecito Water District, and Carpinteria Water District. 6 Reclamation’s proposal does not include use of water stored in Glen Annie Reservoir. Reclamation reported that it has not diverted, stored or used water as authorized under permit 11309 (Glen Annie Reservoir) in any years of available records (2003 through 2013) as provided in the California State Water Resources Control Board— Electronic Water Rights Information Management System (information search of July 10, 2014). Additional information is provided in the California State Water Resources Control Board’s July 28, 2010, order denying Reclamation’s petition for an extension of time regarding permit 11309 (e.g., It is unclear whether or how much water [Reclamation] has ever put to beneficial use under this permit.) (SWRCB 2010). 13 reservoir and outlet works have maximum capacities of 470 ac-ft and 40 cfs. Generally water from Glen Annie Dam is not released downstream except when necessary to maintain damsafety concerns. Additional details concerning these reservoirs can be found in Bureau of Reclamation (2013a).
Critical drought operations
Reclamation defines critical drought conditions to occur when “project water” stored in Cachuma Reservoir is less than 30,000 ac-ft, regardless of the total amount of water stored in the reservoir.7 Reclamation confirmed their definition of “project water” intended for the proposed action in a later dated June 10, 2015 (Bureau of Reclamation 2015b). When the amount of project water stored in the reservoir is less than 30,000 ac-ft, Reclamation proposes to conduct water releases from Bradbury Dam in the following manner until the amount of project water stored in Cachuma Reservoir increases to 60,000 ac-ft:
• Hilton Creek water-releases: Release 2.0 cfs to Hilton Creek when water stored in the reservoir for the purpose of fish-passage flow supplementation or adaptive management is available (see Section 1.3.2, Measures for Conserving Endangered Steelhead) and the Hilton Creek water system is operable. Once the water stored for fish-passage supplementation and adaptive management has been depleted or the Hilton Creek water system is not capable of delivering water, water releases would revert to the stilling basin via the dam outlet works at no more than 30 ac-ft per month. • Stilling basin water-releases: Release no more than 30 ac-ft per month (e.g., 0.5 cfs continuous release) to the stilling basin when water stored for fish-passage flow supplementation or adaptive management is not available or the Hilton Creek water system is not operable.
• No water will be released from Bradbury Dam (either the stilling basin or Hilton Creek) when total reservoir storage is less than 12,000 ac-ft.
Physical maintenance of the project
The following summary of the proposed maintenance activities is organized into three general categories: (1) Bradbury Dam and appurtenant facilities, (2) the Hilton Creek watering system, and (3) the Tecolote Tunnel and South-Coast Conduit.
With regard to maintenance of Bradbury Dam and related facilities, Reclamation proposes a number of activities to ensure the Project would be operated consistent with the intended purpose, which is capture, storage, and delivery of surface water. To this end, the proposed
7 In a letter dated March 9, 2015, Reclamation calculated the amount of project water stored in Cachuma Reservoir to be less than 30,000 ac-ft when the total amount of water in the reservoir was about 54,800 ac-ft (Bureau of Reclamation 2015a). This calculation was based on Reclamation’s interpretation that the term “project water” excludes (a) water stored for downstream groundwater replenishment (water-rights releases), (b) water allocated to Cachuma Member Units in the previous year, but not delivered, and retained in storage (carry-over water), and (c) the reservoir minimum-pool volume (12,000 ac-ft) (Bureau of Reclamation 2015a and b). This is contrary to Reclamation’s previous definition: “Project Water” shall mean all water that is developed, diverted, stored, or delivered by the United States pursuant to Project Water Rights (Bureau of Reclamation 1996). 14 action involves activities that would physically ensure the integrity and long-term operation of Bradbury Dam and the South Coast Conduit reservoirs (Table 1-3).
In regard to the Hilton Creek watering system, Reclamation proposes to conduct the following maintenance:
• Annually inspect intake snorkel in Cachuma Reservoir. • Annually exercise butterfly valves at pipeline outlets. • Annually inspect and maintain packing box and realign coupling. • Change anti-friction bearing oil after each 3 months of pump operation. • Inspect and grease coupling after each 3 months of pump operation. • Replace shaft seal packing after each 6 months of pump operation.
Regarding maintenance of the Tecolote Tunnel and South Coast Conduit, Reclamation proposes the following:
• Dewater, inspect and maintain Tecolote Tunnel approximately every six years, which would require discharges to Glen Annie Reservoir of 1.9 ac-ft for draining and 17.9 ac-ft per day for flushing debris through the Tecolote Tunnel. • Annually test South Coast Conduit “blow-off” valves resulting in discharge of 1,000 gallons or less of water, at a rate of less than 0.2 cfs, into adjacent associated streams.
Discharge of water associated with annual “blow-off” valve inspection would not occur following proposed replacement of valves over the next five years. • Periodically maintain South Coast Conduit resulting in discharge of 0.3 ac-ft to 1.5 ac-ft of water, at a rate of less than 0.2 cfs, into adjacent streams. This includes the proposed “blow-valve” replacement over the next five years.
• Drain, clean and disinfect Carpinteria Reservoir once every two years resulting in discharge of approximately 0.5 cfs in Carpinteria Creek for two days. 15 Table 1-3. Summary of the proposed activities for maintaining Bradbury Dam, adjacent grounds, and related structures and equipment. Readers wishing additional details regarding these activities should access Bureau of Reclamation (2013a).
Activity Frequency of activity
Visual inspection and maintenance of Bradbury Dam
and appurtenant structures and equipment, and test
operational of equipment. Valve overhauls require
closing high-pressure gates and less than 2 ac-ft of
water is drained from the penstock outlet works into
the stilling basin. Maintenance of the stilling basin
may require dewatering. Exercise gates and valves at
Bradbury Dam, apply cleaning solvents, lubricants,
and paint.
Generally visual inspections undertaken at least once a year; maintenance undertaken on an as-needed basis.
Gates and valves at Bradbury Dam are exercised
monthly or annually depending on the structure.
Outflow structures are inspected annually, and valve
overhauls undertaken about every five years. Visual
inspection of stilling basin occurs about every three
years. Radial spillway gates at Bradbury Dam usually
only exercised when water-surface elevation less than
spillway elevation.
Maintaining perimeter fencing to limit access and
provide security.
Grade dirt roads with potential for removal of minor
amount of vegetation.
Fences may be installed or repaired annually with handheld power tools or heavy equipment when necessary to transport materials or lend additional power.
As necessary after large storms.
Hand removal of organic debris, trash, weeds, and
vegetation from dam, spillway and collection basins,
including stilling basin (applies to all dams and
spillways considered under Reclamation’s proposed
action) to ensure integrity of Project structures and
allow access to and visual inspection of facilities.
Application of herbicides and mowing. Potential for
debris stockpiling on adjacent lands.
Generally undertaken as necessary to maintain
structural integrity and operation of the dam, spillway and stilling basin. Weed abatement and vegetation
removal is performed many times annually, but
typically focused in spring and fall.
Rodent and pest control is performed to maintain the
structural integrity of dams and reservoirs.
Installation and maintenance of reusable traps to
control rodents and pests.
Several times a year.
Maintenance of five USGS gaging stations, in
addition to general maintenance described above,
may include modification of water-intake pipes
located in or on the river bed or redirection of lowflow channel, or both. Gaging stations may occasionally be relocated. Maintenance or relocation
of gaging stations may require dewatering portions of
the river.
Maintenance undertaken on as-needed basis, principally
during the dry season with manual equipment (hand
tools). Relocation occurring infrequently during the dry season after large flood-discharge events.
1.3.2 Measures for Conserving Endangered Steelhead
Reclamation proposes the following measures to minimize adverse effects of the proposed action on endangered steelhead: (1) passage-flow supplementation, (2) rearing-flow supplementation, (3) water release ramping rates, (4) mixing criteria for out-of-basin water imports, (5) adaptively managed water releases, (6) steelhead rescue, (7) monitoring and reporting, (8) management plan for beaver and non-native aquatic species, and (9) a plan for adaptively adjusting the anticipated amount of annual incidental take.
16 Passage-flow supplementation
Reclamation proposes 3,200 ac-ft of water stored in Cachuma Reservoir to supplement flows in the Santa Ynez River downstream of Bradbury Dam. These supplemental water releases are intended to provide upstream and downstream migration opportunities for endangered steelhead.
The allocation of stored water, not to exceed 3,200 ac-ft8 , for passage supplementation is
generated or replenished when Cachuma Reservoir spills (e.g., Winter Storm Operations).
Supplementation releases are intended to provide a minimum of 14 days of flow receding from 150 cfs to 25 cfs, measured at USGS Solvang gaging station (USGS 11128500), for selected storm-induced flow events. Reclamation proposes that the timing of these releases would be determined by an assigned committee (Real-Time Decision Group9) using the following prerequisite decision criteria:
• Storm occurs January through May, except that the first storm in January will not be supplemented;
• Santa Ynez River flows measured at the USGS Solvang gaging station are 25 cfs or greater;
• Salsipuedes Creek cumulative average daily discharge since December 1st is 1,000 ac-ft or greater;
• The Santa Ynez River must be open to the ocean (i.e., no sandbar formed across the river mouth); and
• Storms will not be supplemented if: (1) the Real-Time Decision Group determines that there is a greater biological benefit not to supplement a particular storm or series of storms; (2) the Santa Ynez River flow measured at the Solvang gaging station reaches 25 cfs or greater (see above criteria) within seven days following a previous fish-passage supplementation release; or, (3) the water stored for fish-passage supplementation (3,200 ac-ft) has been exhausted or is not adequate for a complete fish-passage supplementation release.
Rearing-flow supplementation
Reclamation proposes to release water from Cachuma Reservoir to maintain the following minimum discharges in Hilton Creek and the Santa Ynez River. A prerequisite to releasing this
8 The proposed allocation of up to 3,200 ac-ft for passage-flow supplementation is a portion of the total increased reservoir storage (9,200 ac-ft) owing to Reclamation extending the radial gates on Bradbury Dam in 2004; the remaining 6,000 ac-ft of increased storage is allocated to main stem rearing-flow supplementation (5,500 ac-ft) and an adaptively managed flow account (500 ac-ft). Reclamation proposes that the full 3,200 ac-ft allocation only applies when the reservoir spills more than 20,000 ac-ft in a given water-year. Reservoir spills less than 20,000 ac-ft may result in allocation of some stored water for fish-passage supplementation (<3,200 ac-ft) when additional reservoir storage is more than 5,500 ac-ft (i.e., priority of additional storage is allocated to rearing-flow supplementation).
9 The Real-Time Decision Group is comprised of Reclamation’s South Central California Area Office’s project biologist and operation’s engineer, and Cachuma Operation and Maintenance Board’s biology staff. 17 water is that Reclamation is not operating Bradbury Dam under the proposed critical-drought operations or non-native aquatic nuisance species control plan:
• Hilton Creek: ≥2 cfs.
• Santa Ynez River at HWY 154 Bridge: 10 cfs during water-years when Cachuma Reservoir spills more than 20,000 ac-ft; 5.0 cfs when Cachuma Reservoir does not spill (or spill is less than 20,000 ac-ft) and storage is greater than 120,000 ac-ft; and 2.5 cfs when Cachuma Reservoir storage is between 30,000 ac-ft and 120,000 ac-ft. • Santa Ynez River at Alisal Road Bridge: 3.0 cfs during water-years when Cachuma Reservoir spills more than 20,000 ac-ft.; and 0 cfs during water-years when Cachuma Reservoir does not spill more than 20,000 ac-ft.
When implementing critical-drought operations or non-native aquatic nuisance species control, Reclamation proposes to release no more than 2.0 cfs from Bradbury Dam (estimated to occur 14% of the time). These water releases are expected to maintain surface flow in the Santa Ynez River below the dam for a distance of only about 0.7 miles during the dry season. Under certain reservoir conditions during critical drought operations, the proposed action would provide water releases only to the stilling basin (30 ac-ft per month) when the total water stored in Cachuma Reservoir is about 30,000 ac-ft or less, or not at all when total reservoir volume is less than 12,000 ac-ft.
Water-release ramping rates
Reclamation proposes specific ramp-down flow rates to reduce the likelihood that endangered steelhead would be displaced or stranded as a result of Winter Storm Operations and water rights releases. Ramping frequency is maintained at one ramping increment for a specified duration, and the ramping rates are scaled according to release magnitude (e.g., when releases are between 5 and 10 cfs, the ramping rate is 2.5 cfs every four hours; releases between 3.5 and 5 cfs, have a corresponding ramping rate of 1.5 cfs every four hours; and releases between 2.5 and 3.5 cfs, have a corresponding ramping rate of 1 cfs every four hours). These ramping rates are outlined in Reclamation’s BA of November 2013 with further reference to Reclamation’s BA of June 2000.
18 Adaptively managed water releases
The proposed action includes filling a 500 ac-ft water account in years when Cachuma Reservoir spills more than 20,000 ac-ft. Water from this account will be released opportunistically and at the discretion of an adaptive management committee. Although the prospective members of the adaptive management committee are not defined in Reclamation’s proposed action (Bureau of Reclamation 2013a), Bureau of Reclamation (2007) indicates that Reclamation intends for the committee to be chaired by Reclamation and comprised of one representative each from Reclamation, NMFS, CDFW, Cachuma Conservation Release Board, Santa Ynez River Water Conservation District (SYRWCD), SYRWCD-Improvement District No.1, and the City of Lompoc. The purpose of these releases is to benefit endangered steelhead (e.g., extending the duration of the passage-supplementation flows or extending the main-stem rearing releases). No criterion is proposed to guide decisions of the adaptive management committee for managing this account.
Steelhead rescue
If drought conditions or unforeseen circumstances preclude water releases from Bradbury Dam to the Santa Ynez River, Reclamation proposes to capture and relocate endangered steelhead from the river and Hilton Creek as necessary to conserve endangered steelhead (Appendix 2-C, Bureau of Reclamation 2013a). Steelhead rescues, if needed, would follow Reclamation’s proposed Santa Ynez River Fish Rescue Plan. This specific plan was recently updated and expanded (Bureau of Reclamation 2015k). The updated plan proposes steelhead rescues in the context of the following:
• Critical-drought operations
• Potential drought operations
• Standard operations of Bradbury Dam
that affect the main-stem river
• Streams crossed by the South-Coast
Conduit
• Hilton Creek watering system
interruptions or failures
• Diminishing streamflows
• Degraded water-quality conditions
• Contaminant spills
• Fish-enhancement projects
• Project monitoring and trapping activities
• Activities associated with proposed activities
that are covered by this latest consultation,
including activities proposed as part of
operating and maintaining Bradbury Dam
This updated plan proposes a fish-rescue team and planning and field protocol, post-rescue monitoring, and reporting requirements. Reclamation proposes to coordinate with us on a caseby-case basis to determine the need for implementing the fish-rescue operations.
Monitoring and reporting
Reclamation proposes a program for annually monitoring the Cachuma Project (Bureau of Reclamation 2015h) (elements of the monitoring program are summarized in Table 1-4). The purposes of this monitoring program are to (1) detect adverse effects resulting from the proposed action and document other factors that may be affecting steelhead populations, (2) identify measures that support project operations, yet would enhance conservation of the species, and (3) document the O. mykiss response to restoration or conservation actions taken. Reclamation proposes that the monitoring program may change based on future conditions in the main stem 19 river or tributaries, owing to access or shifts in monitoring objectives. Reclamation proposes to notify us of any changes to the proposed monitoring program. The proposed monitoring program includes a reporting component, which requires that Reclamation would provide us with annual reports. These annual reports would include the data collected each year and preliminary data analysis.
Table 1-4. Summary of Reclamation’s proposed monitoring program. For additional details see Bureau of Reclamation (2013a, 2015h).
Monitoring element Purpose and intent
Visual monitoring of the sandbar at the estuary
mouth.
Identify river connectivity with ocean.
Monitoring target flows and habitat in the
Santa Ynez River and Hilton Creek and other
select tributaries to main stem.
Document attainment of flow targets; characterize changes in river and tributary conditions. Synthesize data on daily flows from existing gages for use in analyses of production, survival and migration rates. Record water-quality parameters to relate O. mykiss production/survival.
Lake profiling at the intake for the Hilton
Creek Watering System.
Inform adjustments of the intake hose and track lake turnover.
Water-temperature monitoring in Hilton Creek. To assure compliance with proposed temperature criteria.
Water-quality monitoring in lower Santa Ynez
River main stem and tributaries.
To assess habitat conditions relative to temperature and dissolved oxygen.
Trapping steelhead migrants in the lower Santa
Ynez River main stem and select north-facing
tributaries.
Document the timing and abundance of immigrant and emigrant adult and juvenile steelhead, in addition to size, condition, and outward physical evidence of anadromy and smolting, and age and genetic analyses based on scale and tissue samples.
Snorkel surveys in the lower Santa Ynez River
main stem and select tributaries.
Develop estimate of fish-species composition, distribution, and relative abundance; document spawning success, over-summering rearing, and use of passage enhancement projects.
Surveys for aquatic non-native species. Document presence, abundance, and distribution of piscine and amphibian (e.g., bullfrogs) predators. Perform stomach-lavage study on largemouth bass to assess consumption of O. mykiss.
Redd surveys in river main stem and selected
tributaries.
Document steelhead production and identify rearing locations.
Monitor project-specific construction
activities.
Evaluate effectiveness of existing fish-passage structures.
Beaver-dam monitoring in river main stem and
selected tributaries.
Track the size and distribution of beaver dams, and identify dams that may require breaching to benefit migration of steelhead adults and smolts.
Prepare annual report Provide NMFS with results of fishery and habitat monitoring.
Plan to manage beaver and non-native aquatic nuisance species The proposed management plan (Bureau of Reclamation 2015i) involves three principal elements: (1) measures for beaver management, (2) measures for managing non-native aquatic 20 nuisance species, and (3) measure for the combined management of both species.
Dams created by beaver within publically accessible reaches of the Santa Ynez River downstream of Bradbury Dam may be modified or removed on an experimental basis. The intent of this effort is to inform an understanding of how beaver-dam management increase opportunities for O. mykiss movement. The specific protocol for modifying and removing beaver dams may involve physical notching, lowering the overall dam height, and either partial or complete removal. Either hand tools or heavy machinery would be used to effect the modification and removal, depending on whether the channel is dry (heavy machinery) or wet (hand tools). Structures may be installed in the dams (e.g., perforated flex pipes), to encourage passage of steelhead. Beaver-deterrent devices may be used to inhibit the animals from rebuilding or repairing dams.
The plan to manage beaver includes monitoring to assess the effectiveness of the experimental dam modification or removal for improving O. mykiss passage conditions. The proposed monitoring primarily consists of snorkel surveys to assess presence of migrants at the downstream-side of the dam before and after modification or removal. Reclamation adds that the pit-tagging effort associated with the trapping and tagging program under the broader Lower Santa Ynez River Monitoring Program may be used to complement the assessment of effectiveness.
Reclamation proposes a number of measures to avoid or minimize adverse effects on endangered steelhead when modifying and removing beaver dams. These measures include surveys to assess presence of steelhead, installation of exclusion netting to prevent steelhead from entering a workspace, and devices to minimize or avoid water-quality alterations.
A final aspect of the plan to manage beavers involves physical control of the animal within publically accessible reaches of the Santa Ynez River downstream of Bradbury Dam. In this regard, Reclamation’s proposal discusses the potential for trapping and relocating, sterilizing, and euthanizing beaver.
With regard to management of non-native aquatic nuisance species, Reclamation proposes spearfishing, netting, trapping, and electrofishing to reduce or control non-native fish species in the stilling basin and main-stem river downstream of Bradbury Dam. The principal target species is largemouth bass (Micropterus salmoides), though other non-native aquatic species would be subject to control and reduction. According to the proposal, the stilling basin would likely be dewatered to increase the effectiveness of the control and reduction methods.
Dewatering is expected to be limited to years after a spill, at the end of spring or in early summer.
Regarding the combined management of beaver and non-native aquatic nuisance species, under the proposed action, Reclamation would alter the current water-release target of maintaining 2.5 to 5 cfs or more in the “Highway 154 reach” in about 14 percent of years. No more than 2.0 cfs would be released from Bradbury Dam during a critically dry year (a water year with calculated reservoir inflow ≤4,550 ac-ft) that immediately follows a critically dry or dry year (a water year with calculated reservoir inflow between 4,551 and 15,366 ac-ft). These reduced water releases would be initiated in mid to late-summer and made to Hilton Creek; the releases are not expected to provide surface water in the Santa Ynez River beyond about 0.7 miles downstream of the dam.
The purpose of altering the current target is to control beaver and non-native aquatic nuisance species in the subject reach during critically dry years. Reclamation believes this action would 21 lead to the demise of most beaver and non-native aquatic species in the affected areas.
Reclamation proposes a return to the current water-release target only after sufficient precipitation and inflow to Cachuma Reservoir indicates the following summer would not be characterized as “critically dry.”
Plan for adaptively adjusting the amount of incidental take Reclamation proposes a plan that would adaptively manage incidental take (estimated number of O. mykiss killed or captured) as new information indicates adjustments in incidental take levels are warranted (Bureau of Reclamation 2015g). The proposed plan seeks coverage for incidental take due to annual monitoring, management of beaver and non-native aquatic nuisance species, general operation and maintenance activities of the Cachuma Project, the Hilton Creek Watering System and related flow reductions or interruptions, and rescue of steelhead. Reclamation states that take due to the annual monitoring program is expected to represent the bulk of the take due to the Cachuma Project. Furthermore, the estimated amount of take due to the annualmonitoring program has the potential to change, based on the process Reclamation proposes for estimating annual incidental take due to monitoring. This process relies on the abundance of O. mykiss and environmental conditions (Appendix A and Appendix C in Bureau of Reclamation (2015g). The estimated amount and type of take for the annual monitoring program are detailed in Table 1-5. For all other activities, the estimated amount and type of take are detailed in Table 1-6.
Element that Reclamation withdrew from the proposed action The proposed action originally included maintaining existing steelhead-passage structures in tributaries to the Santa Ynez River, and remediating six passage obstructions in Quiota Creek, tributary to the river (Bureau of Reclamation 2013a). However, in a letter dated April 24, 2015, Reclamation determined they do not possess discretionary authority to implement and maintain fish-passage improvement projects in Santa Ynez River tributaries (e.g., Quiota Creek) as originally proposed and withdrew this element from the proposed action (Bureau of Reclamation 2015a).
22 Table 1-5. Reclamation’s estimated amounts of O. mykiss captured (and tagged) or killed for annual fishery monitoring program (Bureau of Reclamation 2015g). The proposal does not differentiate steelhead life stages. The expected amounts of O. mykiss killed and captured in this table are based on the number of O. mykiss counted during snorkel survey of Hilton Creek the previous fall (S = snorkel) or from weir traps (T = trapping), or predicted from an algorithm (P). As an example for interpreting the expected take levels, a table entry of “10 % S” under the “Number of O. mykiss predicted to be killed” heading should be read as “Reclamation expects no more than 10 % of the number of O. mykiss counted during snorkel survey of Hilton Creek the previous fall will be killed.”
Number of O. mykiss counted or
predicted in Hilton Creek
Number of O. mykiss predicted to
be killed
Number of O. mykiss predicted to
be captured
≤ 250 S 0 0
> 250 S 10 % of S 10 % of T
≤ 500 P 10 % of S 10 % of T
501-1499 P 10 % of T 20 % of P
≥ 1,500 P 10 % of T 40 % of P
Table 1-6. Reclamation’s estimated take levels for operation and maintenance-related activities and steelhead rescue (Bureau of Reclamation 2015g). The proposal does not differentiate steelhead life stages.
Activity Number of O. mykiss predicted to
be killed
Number of O. mykiss predicted to
be captured
Critical drought operations 1 % of the O. mykiss counted in the most recent snorkel survey of
Hilton Creek
10 % of the O. mykiss counted in
the most recent snorkel survey of
Hilton Creek
Beaver and non-native aquatic
species management
5 5
General O&M activities 5 Not specified
Hilton Creek watering system 1 % of the O. mykiss counted in the most recent snorkel survey of
Hilton Creek
Not specified
Steelhead rescue Undefined Not specified
1.3.3 Interrelated and Interdependent Actions
When considering effects of the action on a species or critical habitat, we are required to consider the direct and indirect effects of the action “together with the effects of other activities that are interrelated or interdependent [emphasis added] with that action” (50 CFR §402.02). “Interrelated actions” are those that are part of a larger action and depend on the larger action for their justification. “Interdependent actions” are those that have no independent utility apart from 23 the action under consideration (50 CFR §402.02). The following actions are interrelated or interdependent with Reclamation’s proposed operation and maintenance of the Cachuma Project.
Central Coast Water Authority State Water Project deliveries and releases State Water Project (SWP) water is delivered to Cachuma Reservoir at a rate and amount up to 22 cfs and 14,500 ac-ft. The SWP water is transported and delivered through the Central Coast Water Authority pipeline connected to the Bradbury Dam outlet works. This water is subsequently released from the reservoir into the Tecolote Tunnel-South Coast Conduit. When SWP water deliveries coincide with water rights releases, or proposed fish-passage or fishrearing supplementation, the SWP water may be discharged in the Santa Ynez River. To minimize potential effects on steelhead imprinting owing to out-of-basin water being discharged in the Santa Ynez River, Reclamation proposes that out-of-basin water will not be discharged in the river:
• at any time during December through June if flow in the river extends continuously to the Pacific Ocean.
• at a rate exceeding fifty percent of the total water being released from Cachuma Reservoir.
• at a rate/proportion that results in Cachuma Reservoir water releases in excess of 18oC.
Upper Santa Ynez River Operations Agreement
The Upper Santa Ynez River Operations Agreement (or “pass-through agreement”) provides for storage of water in Cachuma Reservoir in exchange for the City of Santa Barbara’s agreement to defer enlargement of Gibraltar Dam. Santa Ynez River water that would not be captured and stored in Gibraltar Reservoir (e.g., in the case of high-flow events exceeding storage, causing spills, or reduced storage capacity owing to sediment accumulation) can be stored in Cachuma Reservoir for later delivery to the City of Santa Barbara through the Tecolote Tunnel and South Coast Conduit. The maximum amount of water stored in Cachuma Reservoir owing to this agreement would be 8,567 ac-ft. This proposed contract is in addition to water delivered to the City of Santa Barbara under the existing contract between Reclamation and the Santa Barbara County Water Agency.
Stocking hatchery O. mykiss in Cachuma Reservoir
Consistent with the terms of an agreement between Reclamation and the County of Santa Barbara regarding the Cachuma Lake Recreation Area, the County would continue planting imported hatchery O. mykiss into the Cachuma Reservoir. But for the existence and operation of Cachuma Reservoir, the planting of hatchery O. mykiss would not occur. Each year, six plantings of 4,000 to 4,500 pounds of trout in each planting is expected. Independent fish farmers and state hatcheries, some outside California, would continue to represent the source of the planted trout. These planted trout may disperse to the Santa Ynez River downstream of Bradbury Dam when the reservoir spills
Groundwater pumping downstream of Bradbury Dam
Groundwater pumping in and adjacent to the main-stem river is interrelated with operation of Bradbury Dam and Cachuma Reservoir. The available information indicates the groundwater pumping is allowed to continue at levels exceeding those that would occur without Cachuma 24 Reservoir. For instance, the proposed action incorporates criteria for deliberately operating Bradbury Dam to maintain downstream alluvial groundwater basins at deficit levels (e.g., Santa Ynez River alluvial groundwater basin at 10,000 ac-ft of dewatered storage), increasing percolation of Santa Ynez River and tributary inflow below the dam (SWRCB 1973), and releasing water from the dam to recharge alluvial groundwater basins when they become depleted. In this regard, the proposed action has the functional effect of allowing groundwater pumping at a rate and duration that would not otherwise exist. Thus, the effects on endangered steelhead and critical habitat that are due to groundwater pumping in and adjacent to the mainstem river are considered in this biological opinion to the extent the proposed action has the functional effect of allowing groundwater pumping at a rate and duration that would not otherwise exist.
The aforementioned water releases conducted by Reclamation to recharge alluvial groundwater are required by SWRCB water-rights permits for the Cachuma Project and based on Reclamation’s proposal to SWRCB of operations that resulted in amendments to the permits for such purposes (SWRCB 1973, 1989). Because Reclamation retains broad discretion over the timing, rates and duration for water releases at Bradbury Dam, we consider such releases part of the proposed action for operation of the Cachuma Project rather than an interrelated or interdependent action as identified by Reclamation (Bureau of Reclamation 2013a). For example, Reclamation could conduct water releases prior to (and following) a request for releases to recharge depleted alluvial groundwater based on real-time monitoring data and experience.
1.4 Action Area
“Action area” means all areas to be affected directly or indirectly by the federal action and not merely the immediate area involved in the action (50 CFR 402.02). For ease of reference, the action area is presented in context to the geographical components of the proposed action: the Santa Ynez River/Cachuma Reservoir component and the Tecolote Tunnel-South Coast Conduit component.
1.4.1 Santa Ynez River/Cachuma Reservoir
This component of the action area is comprised of the Santa Ynez River from the upstream extent of Cachuma Reservoir (high-water mark) to the Pacific Ocean, including several tributaries (i.e., Hilton, Quiota and Salsipuedes creeks). The lateral extent is delineated by the maximum water surface elevation of Cachuma Reservoir and the boundaries of the Santa Ynez River floodplain.
1.4.2 Tecolote Tunnel-South Coast Conduit
This component of the action area encompasses the water-conveyance system corridor from the intake tower in Cachuma Reservoir to Carpinteria Creek, including all stream channel intersections for an approximate distance of 1,000 feet upstream and downstream10, and the West Fork Glen Annie Creek (inclusive of Glen Annie Dam and Reservoir) and Glen Annie Creek
10 A distance of 1,000 feet upstream and downstream of pipeline-stream intersections was applied based on (1) a conclusion that periodic water discharges from the pipeline would either percolate into the streambed under dry conditions (no flow) or thoroughly mix with existing stream flow over this distance, and (b) the length of stream potentially affected by construction-related activities to repair/remediate exposed pipeline in stream channels. 25 from the pipeline crossings to Goleta Slough.
2.0 ENDANGERED SPECIES ACT:
BIOLOGICAL OPINION AND INCIDENTAL TAKE STATEMENT
The ESA establishes a national program for conserving threatened and endangered species of fish, wildlife, plants, and the habitat upon which they depend. As required by Section 7(a)(2) of the ESA, federal agencies must ensure that their actions are not likely to jeopardize the continued existence of endangered or threatened species, or adversely modify or destroy their designated critical habitat. Per the requirements of the ESA, federal action agencies consult with us, and Section 7(b)(3) requires that, at the conclusion of consultation, we provide an opinion stating how the agency’s actions would affect listed species and their critical habitat. If incidental take is expected, Section 7(b)(4) requires us to provide an incidental take statement (ITS) that specifies the impact of any incidental taking and includes non-discretionary reasonable and prudent measures and terms and conditions to minimize such impacts.
2.1 Analytical Approach
This biological opinion includes a jeopardy analysis and an adverse-modification analysis of the proposed action. The jeopardy analysis relies upon the regulatory definition of “to jeopardize the continued existence of a listed species,” which is “to engage in an action that would be expected, directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of that species” (50 CFR 402.02). Therefore, the jeopardy analysis considers both survival and recovery of the species.
The adverse-modification analysis considers the impacts of the federal action on the value of designated critical habitat for the conservation of a listed species. This biological opinion relies on the regulatory definition of "destruction or adverse modification" of critical habitat, which “means a direct or indirect alteration that appreciably diminishes the value of critical habitat for the conservation of a listed species. Such alterations may include, but are not limited to, those that alter the physical or biological features essential to the conservation of a species or that preclude or significantly delay development of such features” (U.S. Fish and Wildlife Service and National Marine Fisheries Service 2016a (81 FR 7214; February 11, 2016)).
We use the following approach to determine whether a proposed action is likely to jeopardize listed species or destroy or adversely modify critical habitat:
• Identify the range-wide status of the species and critical habitat likely to be adversely affected by the proposed action;
• Describe the environmental baseline in the action area; • Analyze the effects of the proposed action on both species and their habitat using an “exposure-response-risk” approach;
• Describe any cumulative effects in the action area;
• Integrate and synthesize the above factors to assess the risk that the proposed action poses to species and critical habitat;
26 • Reach jeopardy and adverse modification conclusions; and, • If necessary, define a reasonable and prudent alternative to the proposed action.
We rely on the best scientific and commercial data available in formulating this biological opinion. One particular data set involves O’Dowd et al. (2014). In reviewing O’Dowd et al. (2014), Stetson Engineers (e.g., page 53, 2016) commented regarding the appropriateness of the hydrologic analyses – specifically, that the hydrologic analysis over estimates pre-dam Santa Ynez River discharge during the dry season because the available record for pre-dam conditions (i.e., 1908-1918) used in part of the analysis was during a period that represents the wettest period in the last 150 years. Having carefully considered the basis of the comment and, more importantly, the manner which this biological opinion draws upon O’Dowd et al. (2014), we conclude the comment is inconsequential to the analyses and conclusions of this biological opinion.
The portion of O’Dowd et al. (2014) that relies on the 1908 to 1918 period of record (a key basis of the comment) is used in this biological opinion solely to inform a qualitative characterization of the environmental baseline. In addition, the findings of O’Dowd et al. (2014) are consistent with a broader body of information indicating adverse effects of major water development, including operations of Bradbury Dam, on endangered steelhead and designated critical habitat for this species in the Santa Ynez River Watershed.
Although the findings of (O’Dowd et al. 2014) depict the reduction in annual adult steelheadpassage opportunities since Bradbury Dam operations began in about 1954 (i.e., inclusive of operations that differ from the current and proposed operations), and are relative to an estimated unimpaired condition, the trend is consistent with the findings of Reclamation (2013a) and our own regarding the effects of the proposed action. Furthermore, this biological opinion uses the comparative work of O’Dowd et al. (2014) to generally indicate the sorts of existing effects due to the current operations and the kinds of effects that would be perpetuated owing to the proposed action.
We agree that river seepage losses between San Lucas Bridge and H Street should be considered when prescribing water releases from Bradbury Dam (e.g., pages 10 and 40, Stetson Engineers 2016). Hence, certain water releases prescribed in the reasonable and prudent alternative account for the seepage loss, including losses due to the interrelated activity of groundwater pumping. The reasonable and prudent alternative includes an adaptive-management element to ensure the seepage does not preclude hydrologic connectivity for steelhead expression of lifehistory pathways.
The estimates of unimpaired streamflow based on the 1908 to 1918 period (e.g., page 9, Stetson Engineers 2016) are irrelevant to the recommended water releases in O’Dowd et al. (2014). The releases are based on (1) the water-column depths for adult and juvenile steelhead to safely and quickly move between and among habitats, and (2) the river discharge needed to produce the required depth (and hydrologic connectivity).
Notwithstanding the comment regarding use of the Santa Cruz Creek gage (e.g., page 40, Stetson Engineers), use of this specific gage is appropriate for timing certain water-release types at Bradbury Dam to coincide with naturally elevated streamflow in tributaries and main-stem river during and shortly after rainfall. Because promoting hydrologic synchrony is a foundational strategy of the reasonable and prudent alternative, the Santa Cruz Creek gage is referenced 27 therein to ensure real-time management of variable water releases from Bradbury Dam.
Although technical aspects underlying certain types of water-release recommendations have been questioned (e.g., page 45, Stetson Engineers 2016), the recommended water releases of O’Dowd et al. (2014) are nonetheless based on reasonable analyses and account for the migratory behavior and ecology of steelhead. As explained later in this biological opinion, Reclamation’s proposed water releases do not properly account for the migratory behavior and ecology of endangered steelhead. Therefore, our reasonable and prudent alternative draws upon these recommended water releases, and other information, to ensure Reclamation’s action is consistent with requirements of Section 7(a)(2) of the ESA.
2.2 Range-wide status of the species and critical habitat This opinion examines the status of the species (Southern California steelhead DPS) that would be adversely affected by the proposed action. The status is determined by the level of extinction risk that the listed species faces, based on parameters considered in documents such as recovery plans, status reviews, and listing decisions. This informs the description of the species’ likelihood of both survival and recovery. The species status section also helps to inform the description of the species’ current “reproduction, numbers, or distribution” as described in 50 CFR 402.02. The opinion also examines the condition of critical habitat throughout the designated area, evaluates the conservation value of the various watersheds and coastal and marine environments that make up the designated area, and discusses the current function of the essential physical and biological features that help to form that conservation value. The following information summarizes the range-wide status of the Southern California steelhead DPS and designated critical habitat for this species.
2.2.1 The Listed Species
Steelhead are native to coastal streams of Alaska extending southward along the Pacific Coast to northwestern Mexico (Behnke 1992). Historically abundant and widespread, dramatic decreases of wild steelhead abundance in California prompted listing of Southern California steelhead as endangered on August 18, 1997 (National Marine Fisheries Service 1997 (62 FR 43937)). The southern range of the species was extended to the United States-Mexico border on May 1, 2002 (National Marine Fisheries Service 2002 (67 FR 21586)). The endangered status of the species was reaffirmed on January 5, 2006 (National Marine Fisheries Service 2006b (71 FR 834)). The geographic range of the endangered Southern California DPS of steelhead extends from the Santa Maria River, near Santa Maria, to the United States-Mexico border. Recent updated status reviews indicate chief causes for the numerical decline of steelhead in southern California involve urbanization, water withdrawals, channelization of creeks, and man-made barriers to migration (Good et al. 2005, Williams et al. 2011, 2016, National Marine Fisheries Service 2016).
O. mykiss exhibit an anadromous life-history form that spends much of life in the ocean before returning to freshwater for spawning, and a resident form that lives entirely in freshwater. Only the anadromous form downstream of long-standing impassible barriers to upstream migration are listed under the ESA (National Marine Fisheries Service 2006b (71 FR 834; January 5, 2006)), and the terms “steelhead” and “anadromous O. mykiss” are used synonymously in this biological opinion. Southern California steelhead are a “distinct population segment” or DPS. The “population unit” is used in this biological opinion to mean an individual steelhead-bearing watershed.
28 The anadromous and resident forms can be sympatric and genetically similar, and the resident form can produce anadromous progeny and vice versa (Zimmerman and Reeves 2000, McPhee et al. 2007, Kendall et al. 2015). The innate ability of O. mykiss to produce anadromous individuals is sufficiently strong to resist decades-long freshwater confinement (Thrower et al. 2004). These findings emphasize the survival advantage of the resident form to the anadromous form, particularly under certain environmental conditions such as drought.11 Within the action area, particularly the Santa Ynez River Watershed, evidence indicates wild populations of indigenous steelhead were naturally present prior to the construction of Bradbury Dam in early 1950 (Garza and Clemento 2007, Alagona et al. 2012). Contemporary populations of O. mykiss residing upstream of many dams in southern California, including Bradbury Dam, are descendent of native coastal steelhead trapped at the time of dam construction (Clemento et al. 2009). The Santa Ynez River was historically one of the most important waterways in all of southern California for the production of steelhead (Boughton et al. 2006, Alagona et al. 2012) and remains an essential waterway for recovery of this species (National Marine Fisheries Service 2012c).
In the following paragraphs, we summarize steelhead life history and habitat requirements, particularly emphasizing the flow-related dependency of aquatic habitat and the inextricable connections among flow, riverine habitat, and steelhead life history, habitat requirements, and population metrics (Shapovalov and Taft 1954, Barnhart 1986, 1991, Harvey et al. 2005, Spina et al. 2005, Harvey et al. 2006, Ligon et al. 1995, Kondolf 1997, Poff et al. 1997). Additional information on the biology and ecology of this species can be found in the Southern California Steelhead Recovery Plan (National Marine Fisheries Service 2012c) (see also Bjornn and Reiser 1991 for life history and habitat requirement information generally pertaining to the species, some of which is included in this presentation).
The major freshwater life-history stages of steelhead considered here involve river entry and upriver migration of adults to spawning habitat, adult spawning and incubation of embryos, freshwater rearing of juvenile steelhead, and smoltification and emigration of juveniles to estuary (including freshwater lagoons) and ocean. Each of these is summarized as follows.
River entry and upriver migration of adults to spawning habitat When elevated river discharge is sufficient to breach the sandbar at the river mouth and create attraction flows (usually in winter and early spring), adult steelhead leave the ocean and enter the freshwater river, typically their natal waterway. Here they begin what can represent a long upriver journey to natal spawning areas. Serving as an environmental cue, the elevated river discharge during and shortly after periods of rainfall is essential for creating and maintaining migration opportunities. The opportunities allow adult steelhead to swim upriver and navigate physical features that may normally constitute an impediment during periods of relatively low river discharge. In this regard, the migratory behavior and ecology of adult steelhead is strongly associated with the natural pattern (i.e., timing, frequency, duration, rate of change) and magnitude of river discharge (Shapovalov and Taft 1954).
11 Because the resident form of O. mykiss contributes to the viability of the anadromous form (e.g., Boughton et al. 2006), a discussion of the resident form is provided in this biological opinion solely to allow a better understanding of how the proposed action would affect the anadromous form. 29 The intended destination of adult steelhead in unimpaired waterways can include the upper reaches and interconnected small tributaries. In such areas the flow-related characteristics and channel-bed conditions are well suited for the production of young (Montgomery et al. 1999).
Indeed much of the spawning and rearing habitats for steelhead are often concentrated in upper reaches in a watershed. Steelhead must arrive at spawning areas at the proper time and in relatively good condition to increase the likelihood that the life cycle would be completed.
Delayed upriver migration can lead to energy costs to migrants and failure to reach spawning areas (Hinch and Rand 1998, Geist et al. 2000, Caudill et al. 2006, Caudill et al. 2007).
Adult spawning and incubation of embryos
The magnitude and duration of streamflow contributes significantly to the availability and quality of spawning habitat for steelhead. Streamflow defines the channel area that is wetted and establishes the distribution of water-column depths and velocities that are suitable for spawning.
Upon reaching instream areas with suitable water-column depths and velocities and substrate particle types, female steelhead excavate a depression or pocket in the channel bed with tail undulations sufficient to mobilize certain particle sizes. Into this pocket the female and male steelhead will simultaneously release eggs and milt. Depending on the size of the female and the number of eggs deposited in each pocket, the spawning pair may continue to form new egg pockets in an upstream direction, enlarging the overall size of the nest.
When the adults are spent and spawning is complete, the adults begin the downstream journey with the intention of re-entering the ocean. Occasionally, adult steelhead may remain or become trapped in rivers after spawning, typically as a result of exceedingly low streamflows. This underscores the role of elevated streamflows in facilitating the return journey of the adults to the ocean.
When selecting a site for spawning, an adult female is simultaneously selecting the site where the incubating embryos will remain for 3 to 8 weeks prior to hatching and a few weeks more before emerging from the nest and beginning existence in the water column. Proper development of the embryos and the newly hatched young that remain in the gravel is best supported with spawning gravels that are relatively free of sand and smaller particles, typically found where gravel deposits are naturally mobilized and the fines flushed by elevated flows, which allows cool, clean, and well-oxygenated water to percolate through the nest. Depending on the location and depth of the gravel pocket that contains the young, nests can be susceptible to the negative effects of subsequent high flows that are capable of scouring the channel bed, although salmonids have evolved in this environment and typically select relatively stable spawning sites when given choices.
Freshwater rearing of juvenile steelhead
Before summarizing freshwater-rearing characteristics of juvenile steelhead, an understanding of the basic model for the behavior and ecology of this life stage is useful for understanding the basis for the effects of the proposed action, presented later in this biological opinion.
Upon emerging from the gravel and beginning existence in the water-column, juvenile steelhead must find suitable habitat to sustain growth and survival. Yet, habitat requirements of juvenile steelhead change as they grow, and environmental features and conditions can influence the quality and availability of habitat for juvenile steelhead. These factors can compel juvenile steelhead to undertake movements to suitable habitat that ultimately lead to production of large 30 smolts and a likelihood of better ocean survival (Bond et al. 2008, Hayes et al. 2011). This underscores the value of hydrological connectivity within a watershed for growth and survival of juvenile steelhead; a watershed showing hydrologic connectivity12 would favor successful expression of various life history pathways (e.g., emergence of young in upstream tributaries and movement downstream in spring and early summer to the main stem river or estuary, and upstream return in fall, Hayes et al. 2008, Hayes et al. 2011). By contrast, a watershed with limited hydrologic connectivity restricts fish movement and may only marginally support, if at all, these pathways, limiting life-cycle pathways and increasing risk of cohort failure. Limited hydrologic connectivity decreases the potential that the physicochemical capacity of the watershed would be able to sustain juvenile growth and survival, and produce large smolts which are key to population success. With this basic model of behavior and ecology in mind, we now move to summarize the freshwater-rearing characteristics of juvenile steelhead.
The open water column within a stream represents the initial site of rearing for juvenile steelhead, from the emergence of fry to the time when juveniles have grown sufficiently large for their seaward migration. The yolk-sac fry emerge from nests about 2 to 6 weeks after hatching, and forage along low-velocity low-relief channel margins and utilize gravel-cobble substrate and instream vegetation for cover. At first the fry congregate in schools, but as time passes the fish grow and spread throughout the stream, selecting individual territories with access to adequate cover and food (Shapovalov and Taft 1954).
Upon reaching around 70 to 80-mm in length, age-0 steelhead typically associate with lowvelocity shallow areas of the stream, and constituent habitats such as shallow riffles and runs (Spina 2003, Spina et al. 2005). As juvenile steelhead grow, the habitats they prefer change and we see larger, older juveniles preferring deeper water, including pools for over-summering. In addition to water-column depth, the age-1 and older juveniles can associate with large woody debris, boulder clusters, and undercut stream banks. The larger, older juveniles may be more restricted to the parts of the watershed that provide shaded perennial pools of sufficient depth.
Such habitats can be primarily concentrated in headwater streams well-fed by orographic precipitation, where baseflows are stable, riparian canopies relatively complete, and geomorphic processes produce an abundance of pools (Harrison and Keller 2007, Boughton et al. 2009).
During the dry season in systems that are hydrologically connected, juvenile steelhead can access these seasonal retreats within the available watershed network as dry-season flows decline and water quality changes (Bramblett et al. 2002, Hayes et al. 2011).
The opening and closing of estuaries is typically related to the magnitude of streamflow and the marine processes that build a sand berm at the mouth of each river system (Jacobs et al. 2011, see also Rich and Keller 2011). Some juvenile steelhead over-summer in these habitats, where rapid growth can lead to smoltification at an early age and large size at ocean entry, which enhances survival to adulthood (Ward et al. 1989, Hayes et al. 2008). In addition to supporting individual fish that migrate directly to the ocean, estuaries provide a seasonal rearing area for juvenile steelhead that subsequently migrate to and rear in upstream reaches (Hayes et al. 2011).
The presence of a properly functioning estuary in a watershed is crucial for allowing juvenile
12 We use the term hydrologic connectivity to mean surface-water connectivity between tributary streams and the main-stem river, surface-water connectivity through the main-stem river to the estuary (and ocean), and the connectivity or interaction between groundwater and surface-water. 31 steelhead to pursue life-history pathways that favor growth and increases the likelihood of smoltto-adult survival (Bond et al. 2008).
In fall and winter, baseflows can rebound in certain sections or reaches of streams as atmospheric temperature drops, and channels formerly dry during the summer can begin flowing again, even before the first wetting rains arrive (Boughton et al. 2009). Juveniles captive in isolated habitats and reaches can now gain access to a much larger area of instream habitat. During winter high flows, juvenile salmonids temporarily seek low velocity, off-channel habitats such as backwater pools, side channels, and inundated woody riparian vegetation that serve as refugia.
Smoltification and emigration of juveniles to ocean
Transformation of steelhead parr into smolts is the preparation for ocean existence and includes changes in shape and color, osmoregulation (salt balance) and energy storage (Quinn 2005). The species become smolts and migrate to the ocean at an early age, typically before age 3 (Hayes et al. 2008, Hayes et al. 2011). Larger size at ocean entry is known to increase ocean survival and return of adults to natal streams (Ward et al. 1989, Bond 2006). For this reason, a waterway that produces a large number of sizeable smolts is expected to experience high returns of adult steelhead.
The downstream movement of juvenile steelhead appears related to photoperiod, temperature, and the magnitude of streamflow, with periods of elevated discharge during and shortly after rainfall events witnessing the largest number of downstream migrants (Spina et al. 2005). The strong positive association between the number of downstream migrants and magnitude of streamflow underscores the importance of streamflow magnitude for ensuring that the emigrants reach intended downstream destinations. As a result, factors that artificially affect the pattern and magnitude of streamflow have the potential to impact migration opportunities for smolts and their arrival at target habitats. In addition to low streamflow, high water temperature, physical barriers, low dissolved oxygen, and high turbidity can delay or halt downstream migration of juveniles and subsequent entry into estuary or ocean (Bjornn and Reiser 1991).
Hydrologic connectivity in a coastal watershed is essential if juvenile steelhead are to undertake the annual downstream migration to river main stems and subsequently the estuary as part of its anadromous life cycle. Watersheds with ample hydrologic connectivity allow juveniles to leave upper reaches and migrate downstream through progressively large tributaries and arrive at main stem confluences. Subsequently, juveniles may migrate downstream through river main stems, ultimately reaching the estuary and, for some individuals, the ocean. This route of travel contrasts with the truncated route of juveniles in watersheds were intermittent hydrologic connectively precludes individuals from safely transitioning from one reach to another, often trapping the fish in habitats prone to desiccation, especially in watersheds where water development is prevalent.
For smolts that successfully reach the ocean, the individuals can grow and reach maturity at age 2 to 5 while in the ocean (Shapovalov and Taft 1954). This ocean-going life history pattern, known as anadromy, leads to more rapid growth because of abundant food sources than can be accomplished by non-anadromous individuals that spend their entire life in freshwater.
2.2.2 Population Viability of the Listed Species
One prerequisite for predicting the effects of a proposed action on a species, i.e., the DPS, includes an understanding of the status of the species, that is, whether the species is likely to 32 experience viability (the hypothetical state in which extinction risk of the DPS is negligible over a 100-year period and full evolutionary potential is retained; Boughton et al. 2006). We equate the likelihood of viability with the likelihood of both the survival and recovery of the species for purposes of conducting the jeopardy analysis under section 7(a)(2) of the ESA.
Four principal parameters were used to evaluate the extinction risk for the populations that make up the endangered Southern California DPS of steelhead: abundance, population growth rate, population spatial structure, and population diversity. These specific parameters are important to consider because they are predictors of extinction risk and reflect general biological and ecological processes that are critical to the growth and survival of steelhead populations (McElhany et al. 2000). Guidelines or decision criteria have been defined for each of the four parameters to further the likelihood-of-viability evaluation, and these guidelines were considered and are emphasized for ease of reference in the following evaluation. Because certain guidelines are related or overlap, the evaluation is at times necessarily repetitive. Although we apply this evaluation solely to the anadromous form of O. mykiss (i.e., one segment of the species), there is no ecological rule precluding such application to a specific form of a polymorphic species and the anadromous form is considered a distinct population segment of O. mykiss (National Marine Fisheries Service 2006b).
Before proceeding with the evaluation of each of the four population parameters above, a common understanding of the meaning of population viability and the key underlying concepts, which provide the basis for judging the persistence of a population in the wild, is needed. We describe three concepts in the next paragraph; the bases for these concepts can be found in the scientific literature regarding population ecology, conservation biology, and extinction risk (e.g., Pimm et al. 1988, Primack 2004, see also McElhany et al. 2000). Comprehending these concepts is necessary for understanding the basis for NMFS’ conclusion regarding the likelihood of viability for the endangered Southern California Steelhead DPS. There are three basic concepts (adapted from Boughton et al. 2006) that are fundamental to the viability analysis. This summary review of the concepts concludes with a brief discussion of how these concepts are expected to apply to the endangered Southern California Steelhead DPS. After concluding the description of these concepts, we evaluate each of the four population parameters.
The first concept is that for a population to persist indefinitely, each adult fish in the population, on average, has to give rise to at least one adult fish in the next generation (i.e., the population of adults must replace itself year after year). In nature, population abundance fluctuates for a variety of reasons including environmental stochasticity. If the fluctuations are large enough, the number of individuals in the population can fall to zero, even though the population may be relatively large initially. There are certain traits that reduce the likelihood that a population would be driven to extinction by random events, which leads us to the second concept.
The second concept involves the size of the population. The larger the population, the less likely the population is to become extinct. In nature, the number of births, deaths, and matings are important to the viability of a population. Essentially, the likelihood of extinction is reduced if the birth rate is high (the population is replacing itself – the first concept). In the case of death rates, the larger the population, the less likely that random deaths will cause large reductions in the number of individuals in the population. High birth rates and low death rates favor persistence of the population. In the case of matings, the larger the population, the larger the number of potential mates and the reduced likelihood that individuals will fail to locate a mate.
Similarly, the larger the population, the less likely that all mates will fail to produce eggs. Large 33 population size is the single most important trait to protect a population from being driven to extinction due to random events.
The third concept involves the relationship of vital events (e.g., births and deaths). The more correlated that vital events tend to be across the population, the larger the population must be to reduce the likelihood of extinction. For instance, if environmental stochasticity causes a more or less similar change in death rates across the population, we would say that the death rates are correlated. Similarly, if random perturbations cause birth rates to increase similarly across the population, we would say that the birth rates are also correlated. Now here is the point: if vital events are correlated across the population, we would expect, for example, the death rates across the population to decrease in synchrony (i.e., death rates would decrease across the habitats in which the species exist, not just in localized areas). This is different than a situation where the vital events are not correlated, in which case we would not expect, for example, the death rates across the population to simultaneously decrease. Rather, we would expect that abundance of some individuals in some areas would not decrease. Therefore, if vital events are correlated across a population, a sufficiently large population is needed to reduce the likelihood that chance fluctuations would reduce the number of individuals to zero across the entire population.
These concepts apply to the endangered Southern California DPS of steelhead and are integral to an effective recovery strategy. The role of the largest populations in recovery is based on population theory, which suggests the largest populations would have the highest viability if restored to an unimpaired condition. The influence of environmental stochasticity on the endangered Southern California DPS of steelhead is high, and because environmental stochasticity increases extinction risk to the population, and to compensate for the environmental influences, the Southern California DPS of steelhead therefore needs to have a larger average size than a DPS that is not as affected by chance fluctuations in environmental conditions. The sources of environmental stochasticity in the Southern California DPS involve drought (and associated features such as high temperatures, low streamflow, lack of sandbar breaching at the mouths of rivers), floods, debris flows, and wildfires (National Marine Fisheries Service 2012c).
What follows now is the evaluation of the likelihood of viability for the endangered Southern California DPS of steelhead, beginning with the abundance parameter.
Abundance
Information about population size provides an indication of the sort of extinction risk that a population faces. For instance, small populations are at a greater risk of extinction than large populations because the processes that affect populations operate differently in small populations than in large populations (Pimm et al. 1988, Primack 2004). As a result, variation in environmental conditions leading to low levels of species survival or fecundity for extended time can cause extinction of small populations. What follows is an evaluation of the abundance of steelhead populations in the DPS in the context established by the guidelines for the abundance parameter (i.e., viable population size guidelines, McElhany et al. 2000). The endangered Southern California DPS of steelhead, a collection of individual population units, must meet all of the population guidelines to be considered viable with regard to the abundance parameter.
A population unit should be large enough to have a high probability of surviving environmental variation of the patterns and magnitudes observed in the past and expected in the future.—The population viability analysis conducted by NMFS Southwest Fisheries Science Center’s Technical Recovery Team indicates that 12,500 adult steelhead per generation (3 years 34 for steelhead) (or 4,150 steelhead per year13) are needed for each individual population unit (steelhead-bearing watershed) identified in the Southern California Steelhead Recovery Plan if the Southern California DPS is to be viable (Boughton et al. 2007, National Marine Fisheries Service 2012c). The historical run size of adults within the Southern California DPS of steelhead was roughly estimated to be at least 32,000 to 46,000 based on four watersheds (Santa Ynez River, Ventura River, Santa Clara River, and Malibu Creek); yet recent total run sizes for the same four watersheds and the DPS was estimated at less than 500 adults (Good et al.2005, Williams et al. 2011, 2016).
A population unit should have sufficient abundance for compensatory processes to provide resilience to environmental and anthropogenic perturbations.—The developers of the numerical population viability threshold arrived at the value of 12,500 adult steelhead per generation (or 4,150 adult steelhead per year) based on the expectation that the numerical threshold would be sufficient to, in part, combat influences of environmental variability (e.g., irregular inter-annual patterns of precipitation) on the risk of extinction, without consideration of other influences such as anthropogenic activities (Boughton et al. 2007). Because current abundance of adult steelhead in the endangered Southern California DPS is substantially lower than the viability threshold (Williams et al. 2011, 2016), the current abundance of adult steelhead is not capable of effectively withstanding influences of environmental fluctuations, let alone perturbations due to anthropogenic activities, which are exceedingly widespread throughout the DPS.
A population unit should be sufficiently large to maintain its genetic diversity over the long term.—Genetic variability is important because differing genetic traits favor a population being able to survive and reproduce under variable environmental conditions. Yet, anthropogenic activities (including migration barriers) have selectively eliminated steelhead populations from the DPS (Boughton et al. 2005, Gustafson et al. 2007, National Marine Fisheries Service 2012c), leading us to conclude that the genetic diversity of the species has been reduced (Levin and Schiewe 2001). This conclusion is further supported by findings of empirical studies documenting a decline in effective population size and genetic diversity in Southern California steelhead (Garza and Clemento 2014). That the steelhead populations that make up the Southern California DPS all have extremely low abundance is reason alone to expect a loss of the genetic traits that are needed to respond and adapt to a changing environment because low genetic diversity is characteristic of small populations (Primack 2004).
A population unit should be sufficiently abundant to provide important ecological functions throughout its life cycle.—The number of individuals required to provide such functions depends mostly on the structure of the species’ habitat and biology (McElhany et al. 2000). The number of adult steelhead in the populations of the subject DPS is considerably less than the minimum number of adults needed to maintain the viability of independent populations within the DPS (Boughton et al. 2007, Williams et al. 2011, 2016). The underlying basis for the minimum population viability threshold includes the functional response of steelhead populations to environmental conditions, the species’ biology, ecology, and genetics, as well as consideration of extinction risk (Boughton et al. 2007). Consequently, the minimum population
13 The developers of this numerical prescription acknowledge the criterion may be biologically infeasible for some waterways, particularly small coastal basins, or that smaller, geographically close watersheds may function as a meta-population (Boughton et al. 2007).
35 viability threshold reflects the abundance required to support the expression of biological and ecological functions. With regard to the species’ habitat, a variety of anthropogenic factors have reduced the quality, quantity and diversity of habitat for steelhead (e.g., Busby et al. 1996, National Marine Fisheries Service 2012c), and certain habitat functions have been either eliminated or reduced.
Population Growth Rate
The productivity of a population (i.e., the number of individuals generated over a specified time interval) can reflect conditions that influence the dynamics of a population and determine abundance. Knowledge of the productivity of a population allows an understanding of the performance of a population across the landscape and habitats in which it exists and its response to those habitats (McElhany et al. 2000).
A population’s natural productivity should be sufficient to maintain its abundance above the viable level.—Natural productivity can be measured as the ratio of naturally-produced spawners born in one broodyear to the number of fish spawning in the natural habitat during that broodyear. Under the foregoing scenario, the spawner-to-spawner ratio should fluctuate around
1.0 or higher to maintain abundance, i.e., cohorts should be replacing one another at least equally. While information on natural productivity of the Southern California DPS is lacking, the magnitude of the decline in the abundance of adult steelhead in the DPS indicates the number of spawners has not been replenished and the number of adults in the subject DPS remains at very low levels (Williams et al. 2011, 2016), well below the minimum number of adults needed to maintain the viability of independent populations within the DPS (Boughton et al. 2007).
A viable population that includes naturally spawning hatchery fish should exhibit sufficient productivity from naturally-produced spawners to maintain population abundance at or above viability thresholds in the absence of hatchery subsidy.—We have not found any evidence indicating naturally spawning hatchery steelhead are substantially contributing progeny to the endangered Southern California DPS of steelhead. While extensive and widespread stocking of steelhead occurred in southern California streams historically (Alagona et al. 2012), no anadromous O. mykiss are currently stocked in the DPS. Currently only non-anadromous hatchery reared O. mykiss are stocked upstream of long-standing barriers to anadromy.
Empirical evidence indicates the historical plants from Fillmore Fish Hatchery and hatcheries from northern California have not contributed substantively to the reproduction and perpetuation of native steelhead ancestry in southern California (Clemento et al. 2009, see also AbadiaCardosa et al. 2016). Hatchery fish or not, the natural productivity in the DPS is insufficient to maintain abundance of the DPS above the minimum viability threshold.
A viable population should exhibit sufficient productivity during freshwater life-history stages to maintain its abundance at or above viable thresholds.—The number of adults in the Southern California DPS (Williams et al. 2011) is considerably less than the minimum number of adults needed to maintain the viability of independent populations within the DPS (Boughton et al. 2007). Genetic studies document a decrease in effective population size and genetic diversity, including within the action area (Garza and Clemento 2007, Clemento et al. 2009, Garza and Clemento 2014), both of which indicate a reduction in freshwater productivity. Consequently, the level of production in freshwater has not been sufficient to maintain abundance of the DPS above the minimum viability threshold.
A viable population should not exhibit sustained declines in abundance that span multiple 36 generations and affect multiple brood-year cycles.—Watershed-specific extinctions of wild steelhead have been reported, and abundance remains low (Boughton et al. 2005, Gustafson et al. 2007, Williams et al. 2011, 2016). Recent efforts to monitor abundance of adult run sizes in certain larger watersheds continue to show either no, or extremely low, numbers of returning adults over several years or multiple generations (Williams et al. 2011, 2016).
A viable population should not exhibit trends or shifts in traits that portend declines in population growth rate.— The population growth rate of the Southern California DPS of steelhead has declined to dangerously low levels and many watershed-specific extinctions of this species have been reported (Boughton et al. 2005, Gustafson et al. 2007, Williams et al. 2011, 2016). While information on individual population units of the Southern California DPS is limited, certain watershed-specific populations (e.g., Santa Ynez River) have historic estimates to compare recent data. Contemporary data show that the number of returning adults in some of the larger watersheds (or “core” populations, sensu Boughton et al. 2006) remain at depressed levels (Williams et al. 2011, 2016). The decrease in effective population size noted for Southern California steelhead (e.g., Garza and Clemento 2007, Clemento et al. 2009, Garza and Clemento 2014) suggest a decline in population growth rate.
Population Spatial Structure
Understanding the spatial structure of a population is important because the population structure can affect evolutionary processes and, therefore, alter the ability of a population to adapt to spatial or temporal changes in the species’ environment (McElhany et al. 2000). Populations that are thinly distributed over space are susceptible to experiencing poor population growth rate and loss of genetic diversity. With regard to the Southern California DPS, although the geographic area of the DPS is broad, the individual population units are sparsely and unevenly distributed throughout the DPS with extensive spatial gaps between neighboring population units (Boughton et al. 2005, National Marine Fisheries Service 2012c). This sparse distribution, combined with low numbers, reduces and in many cases likely eliminates support from remaining larger population units to smaller less viable population units given the “source-sink” population dynamics (see Figure 2-2 below). Genetic input from source populations to sink populations is much less likely to occur, and the small size of sink populations can easily lead to loss of genetic diversity.
Habitat patches should not be destroyed faster than they are naturally created.— Anthropogenic activities reduced the number of streams available to steelhead, causing a net increase in the amount of habitat that is lost (Nehlsen et al. 1991, Boughton et al. 2005, Boughton et al. 2006, National Marine Fisheries Service 2012c). Many water-storage projects rendered inaccessible hundreds of miles of spawning and rearing habitats in this DPS, and access to these habitats have not been restored. These projects include Twitchell Dam on the Cuyama River, Bradbury Dam on the Santa Ynez River, Casitas Dam on Coyote Creek, Matilija Dam on Matilija Creek, Santa Felicia Dam and Pyramid Dam on Piru Creek, and Rindge Dam on Malibu Creek (Good et al. 2005).
Natural rates of straying among sub-populations should not be substantially increased or decreased by human actions.—Because anthropogenic activities have rendered certain streams (or habitats needed for specific life-history functions) inaccessible to adult steelhead (Boughton et al. 2005), these adults would need to enter non-natal streams, hence an increase in rates of straying is expected in the DPS. Dispersal of steelhead has been documented in the Southern 37 California DPS, for instance in the case of Topanga Creek and San Mateo Creek (National Marine Fisheries Service 2002, Boughton et al. 2006, Bell et al. 2011). Increased stray rates elevate the potential for reduced population viability, particularly if these fish are accessing unsuitable habitat, and given that much of the habitat condition in southern California is not functioning properly, chiefly as a result of anthropogenic activities, straying into unsuitable habitat is possible and probable.
Some habitat patches should be maintained that appear to be suitable or marginally suitable, but currently contain no fish.—Habitat for this species is neither maintained nor functioning properly. Relative to historical conditions, habitat for steelhead has suffered destruction, modification, and curtailment and is not being maintained (e.g., Nehlsen et al. 1991, National Marine Fisheries Service 1997, Good et al. 2005, National Marine Fisheries Service 2006b, 2012). Construction and the ongoing presence of impassable man-made structures throughout the Southern California DPS have rendered many habitats inaccessible to adult steelhead (Boughton et al. 2005). Within many stream reaches that are accessible to this species (but that may currently contain few or no fish), urbanization and exploitation of water resources (Grantham and Viers 2014) has eliminated or dramatically reduced the quality and amount of living space for steelhead (Bureau of Reclamation and United Water Conservation District 2005, National Marine Fisheries Service 2012c).
Source subpopulations (i.e., population units) should be maintained.—Despite numerous localized efforts to improve and restore habitat characteristics and conditions for steelhead in southern California, overall the habitat supporting source populations is not being adequately maintained. As a result of past and ongoing anthropogenic impacts, the natural processes that are responsible for creating and maintaining habitat for steelhead in many southern California coastal streams are not operating properly (e.g., in the case of a dam affecting the pattern and magnitude of streamflow and the natural movement of sediment and organic material in streams). A detailed review of factors affecting steelhead in southern California streams noted widespread degradation, destruction, and blockage of habitat for steelhead, including habitats supporting source populations (Busby et al. 1996, Good et al. 2005, Boughton et al. 2006, National Marine Fisheries Service 2012c), indicating habitats for source populations have not been maintained.
Population Diversity
Steelhead possess a suite of life history traits, such as anadromy, timing of spawning, emigration, and immigration, fecundity, age-at-maturity, and behavioral adaptations, to mention a few. The more diverse these traits (or the more the expression of these traits are not restricted), the more likely the species is to survive a spatially and temporally fluctuating environment. Factors that constrain the full expression of a trait affect the natural diversity of a species (McElhany et al. 2000).
Human-caused factors such as habitat changes, harvest pressures, artificial propagation, and exotic species introduction should not substantially alter natural variation in species’ traits.— In the Southern California DPS, anadromy has been either eliminated or reduced in many populations due to a variety of anthropogenic factors including the construction of steelheadpassage impediments (Boughton et al. 2005, Good et al. 2005, National Marine Fisheries Service 2005, 2012). All of the larger watersheds that historically supported steelhead now possess complete barriers precluding steelhead from a substantial amount of habitat (Good et al. 2005). 38 Most dams in the DPS do not include features that allow for safe migration of adult and juvenile steelhead (including remnant populations of non-listed steelhead that reside upstream of longstanding barriers) to and from spawning and rearing areas and the ocean. The loss or reduction in anadromy and migration of juvenile steelhead to the estuary or ocean is expected to reduce gene flow, which strongly influences population diversity (McElhany et al. 2000).
Natural processes of dispersal should be maintained – human-caused factors should not substantially alter the rate of gene flow among populations.—The construction and ongoing impassable presence of many dams has altered natural dispersal of steelhead within and between watersheds (Busby et al. 1996, Boughton et al, 2005, National Marine Fisheries Service 2012c) and altered the rate of gene flow in the endangered Southern California DPS of steelhead (Levin and Schiewe 2001). Another factor altering gene flow involves the numerous watershed-specific extinctions of steelhead in the Southern California DPS, many of which are related to anthropogenic activities (Nehlsen et al. 1991, Boughton et al. 2005, Gustafson et al. 2007).
Each watershed-specific population of steelhead can be viewed as a distinct gene pool of individuals that are adapted to the natural environmental conditions and characteristics of its home watershed (Nehlsen et al. 1991, Hendry et al. 2002). Therefore, loss of a watershedspecific population can result in elimination of a substantial amount of genetic diversity and reduced gene flow throughout the DPS (Levin and Schiewe 2001). Evidence indicates genetic diversity in populations of Southern California steelhead is low (Garza and Clemento 2007, Clemento et al. 2009).
Natural processes that cause ecological variation should be maintained.—Because habitat is the “templet” for ecological variation in a species (Southwood 1977), alteration of a species’ habitat impacts the potential of the habitat to promote ecological variation (e.g., in a species’ ability to cope with fluctuating environmental conditions). Significant amounts of the historical habitat for steelhead in southern California streams has been degraded, eliminated, simplified, and rendered inaccessible to the species (Nehlsen et al. 1991, Busby et al. 1996, Good et al. 2005, National Marine Fisheries Service 2012c), and existing habitats are not being adequately maintained over sufficiently broad scales. For instance, trapping of coarse sediment and inversion of flood hydrographs by dams has transformed formerly habitat rich rivers into incised armored hydrologically disconnected reaches capable of providing only migration habitat where formerly rearing habitat existed. In addition the alteration in the pattern and magnitude of discharge downstream of dams or diversions has resulted in a shift in the timing of the freshwater migration corridor or a restricted migration window (e.g., National Marine Fisheries Service 2008a, O’Dowd et al. 2014). Loss or limited migration opportunities adversely affects the species’ basic demographics and evolutionary processes, causing a reduced potential that the DPS can withstand environmental fluctuations.
In summary, the foregoing evaluation demonstrates that the DPS is not viable and is at a high risk of extinction, i.e., low likelihood of viability. The main factors for the high risk of extinction are low, no, or negative population growth rates, very low abundance in remaining populations, sparse and uneven distribution of the remaining populations, and loss of life history traits. Human alteration of the freshwater landscape in which this species spends much of their life-cycle is the main cause of high extinction risk. Water development (dams, surface-water diversions and groundwater extraction) and urbanization (channelization and other flood control activities, transportation networks and increased impervious surfaces) are the main anthropogenic activities that have altered the freshwater landscape this species depends on. This 39 conclusion is consistent with conclusions of past and recent technical reviews of the status of the species (Busby et al. 1996, Good et al. 2005, Williams et al. 2011, 2016), and the listing determinations for the species (National Marine Fisheries Service 1997, National Marine Fisheries Service 2006).
2.2.3 Designated Critical Habitat for Endangered Steelhead The designation of critical habitat for Southern California steelhead uses the term “primary constituent elements” (National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)). The new critical habitat regulations (U.S. Fish and Wildlife Service and National Marine Fisheries Service 2016b (81 FR 7214; February 11, 2016)) replace this term with “physical or biological features.” The shift in terminology does not change the approach used in conducting a “destruction or adverse modification” analysis, which is the same regardless of whether the original designation identified primary constituent elements or physical or biological features. In this biological opinion, we use the term “physical or biological features” to mean “primary constituent elements.”
Section 3 of the ESA defines critical habitat as (1) specific areas within the geographical area occupied by the species at the time of listing, on which are found those physical or biological features that are essential to the conservation of the listed species and that may require special management considerations or protection, and (2) specific areas outside the geographical area occupied by the species at the time of listing upon a determination by the Secretary that such areas are essential for the conservation of a listed species. Because a description of the extensive effort to identify critical habitat for endangered steelhead is beyond the scope of this biological opinion, we refer readers to the final rule regarding designated critical habitat for additional discussion and rationale behind the designation (National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)).
The critical habitat designation identifies physical or biological features of critical habitat designated for the Southern California steelhead DPS. These features include freshwater spawning sites, freshwater rearing sites, freshwater migration corridors, and estuarine areas (see Table 2-1 for a detailed description of these features). Activities with the potential to affect critical habitat for the Southern California steelhead DPS include: (1) forestry, (2) grazing and related rangeland activities, (3) agriculture and related water withdrawals, (4) road building and maintenance, (5) channel modifications, diking and stream bank stabilization, (6) urbanization, (7) sand and gravel mining, (8) mineral mining, (9) dams, (10) irrigation impoundments and water withdrawals, (11) wetland (including estuaries) loss or removal, (12) introduction of exotic or invasive species, and (13) impediments to fish migration. 40 Table 2-1. Physical or biological features (PBFs) of designated critical habitat (source: National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)) that are relevant to this consultation and proposed action.
PBF Description
Freshwater migration
corridor
Free of obstruction and excessive predation with water quantity and quality conditions and natural cover such as submerged and overhanging large wood, aquatic vegetation, large rocks and boulders, side channels, and undercut banks supporting juvenile and adult mobility and survival.
Freshwater spawning
sites
Water quantity and quality conditions and substrate supporting spawning, incubation and larval development.
Freshwater rearing
sites
Water quantity and floodplain connectivity to form and maintain physical habitat conditions and support juvenile growth and mobility; water quality and forage supporting juvenile development; water quality and forage supporting juvenile development; and natural cover such as shade, submerged and overhanging large wood, log jams and beaver dams, aquatic vegetation, large rocks and boulders, side channels, and undercut banks.
Estuarine areas Free of obstruction and excessive predation with water quality, water quantity, and salinity conditions supporting juvenile and adult physiological transitions between fresh and saltwater; natural cover such as submerged and overhanging large wood, aquatic vegetation, large rocks and boulders, and side channels; and juvenile and adult forage, including aquatic invertebrates and fishes, supporting growth and maturation.
We identify here (1) the existing condition of critical habitat throughout the designated area, (2) the value of coastal watersheds within the designated area for the conservation of the listed species, and (3) the value of the Santa Ynez watershed for the conservation of the listed species.
Condition of critical habitat throughout the designated area In this section we describe the current condition of critical habitat for endangered steelhead across the southern California landscape.
Anthropogenic activities have reduced the amount of habitat available to steelhead (Nehlsen et al. 1991, Good et al. 2005, National Marine Fisheries Service 2012c). The damming of streams throughout the region has created physical barriers and hydrological impediments for adult and juvenile steelhead attempting to migrate to and from hundreds of miles of spawning and rearing habitats, and degraded habitat downstream (National Marine Fisheries Service 2012c).
Likewise, construction and ongoing presence of impassable road and highway stream crossings have rendered habitats inaccessible to adult steelhead (Boughton et al. 2005). Within stream reaches that are accessible to this species, but that may currently contain no fish, urbanization has in many watersheds eliminated or dramatically reduced the quality and amount of living space for juvenile steelhead (National Marine Fisheries Service 2014d). Substantial overallocation of water resources (Grantham and Viers 2014) in the absence of meaningful streamflow provisions for steelhead (Spina et al. 2006) continues to reduce and, in certain locations, eliminate the quality and amount of those physical or biological features of critical habitat designated for the Southern California steelhead DPS. 41 Dams have caused the most profound effects, disrupting the natural pattern and magnitude of streamflow and movement of sediment and organic debris in coastal waterways and the estuaries of southern California (Willis and Griggs 2003, National Marine Fisheries Service 2008a, b, National Marine Fisheries Service 2014, O’Dowd et al. 2014). Because the natural movement of water, sediment and organic debris is vital for the creation and maintenance of physical or biological features of critical habitat designated for the Southern California steelhead DPS (Beechie and Bolton 1999, Beechie et al. 2010, Cluer and Thorne 2014), the man-made disruption of natural-fluvial processes has translated into inhospitable habitat characteristics and condition for steelhead, and loss or reduction of important life-history traits such as anadromy, seasonal instream migration, and emigration of juvenile steelhead to the estuary or ocean.
The condition of designated habitat for steelhead can be briefly illustrated through consideration of the functional ability of the habitat to support the life-history requirements of the species.
Much of the historical habitat throughout southern California has been degraded and its ability to support various life-history stages of the species, including migration to and from historical spawning and rearing habitats and the ocean, and over-summering in the river main stem and estuary is severely limited. The construction and ongoing operation of surface water storagediversion projects and groundwater withdrawals, and conversion of wildlands through development and land use, have dramatically reduced the quality and availability of physical or biological features of critical habitat designated for this endangered species and completely eliminated steelhead access to many coastal streams (Busby et al. 1996, Boughton et al. 2005, Good et al. 2005, National Marine Fisheries Service 2012c).
The available information indicates the natural characteristics and condition of river main stems were capable of supporting over-summering of juvenile steelhead (e.g., pp 98-100 in Boughton et al. 2006). Flowing year round, historical accounts indicate main-stem areas possessed extensive riparian corridors and the complexity of mesohabitats (e.g., riffles, runs, pools) that often attract multi-year freshwater rearing of steelhead. Due to a variety of anthropogenic activities, principally development of water resources and flood-control projects, main-stem habitats in the region have been significantly altered in a number of ways. These alterations have eliminated or severely fragmented hydrologic connectivity and diminished the functional value of main-stem habitats for supporting life-history function and habitat requirements of steelhead (Shapovalov 1944, Boughton et al. 2005, National Marine Fisheries Service 2012c).
The estuaries in coastal California provided drought resilient habitat, supporting salmonid populations through extensive drought cycles even when surface flow was disconnected from the estuary, owing to relatively high water tables and groundwater inputs. This drought resilient failsafe habitat has been severely diminished throughout the Southern California DPS.
Although the foregoing is largely representative of most coastal watersheds within the region, a few select watersheds are relatively least disturbed (e.g., Arroyo Hondo Creek, Santa Barbara County). Such watersheds exhibit aquatic habitat characteristics and condition appearing somewhat consistent with life history and habitat requirements of endangered steelhead.
Unfortunately, the number of such waterways in the Southern California DPS are extremely few and generally not ranked high (e.g., because of the watersheds are small) in terms of viability and independence for promoting recovery of this species (Boughton et al. 2006, National Marine Fisheries Service 2012c).
Most estuaries in the action area have experienced significant alterations in quality and extent, reducing the function and value of these essential habitats for growth and survival of endangered 42 steelhead (National Marine Fisheries Service 2012c). Of particular note, a recent comprehensive evaluation reports that the Santa Ynez River Estuary has experienced dramatic impacts owing to anthropogenic activities in the watershed, including construction and operation of major water projects and related modification of the natural-flow regime (ESA PW 2011).
As of this writing, the ongoing drought affecting California has led to unprecedented dry conditions in southern California, including the observation of no flowing surface water throughout reaches that would normally be accessible to steelhead. Many stream reaches that are downstream of introduced migration barriers in the region have experienced little to no flowing surface water for the last three years. These drought conditions have worsened the ongoing effects of anthropogenic activities and related inability of many streams in the region to sustain life-history requirements of this species (Williams et al. 2016, National Marine Fisheries Service 2016).
Despite localized efforts to improve the function and value of habitat for steelhead in southern California, including within the action area over the past decade (e.g., steelhead-passage improvement projects in tributaries to the main stem Santa Ynez River, Bureau of Reclamation 2013a), recent reviews of factors affecting this species across the regional landscape continue to note widespread degradation, destruction, and blockage of habitat, including habitats supporting source or core populations (Williams et al. 2011, 2016, National Marine Fisheries Service 2012c, 2016), largely because the physical processes that create and maintain habitat have not been restored (Cluer and Thorne 2014). The reviews provide evidence that human activities are primarily responsible for alterations to the natural-fluvial processes that are essential for creating and maintaining steelhead habitat in many southern California coastal streams.
Value of coastal watersheds within the designated area for the conservation of the listed species
As part of identifying essential actions for recovering endangered steelhead, NMFS ranked the coastal watersheds in southern California and the population of steelhead occupying each watershed based on its intrinsic potential to support an independently viable population of steelhead14 (Boughton et al. 2006). The rankings ranged from 1 to 3, with a 1 representing the highest value assigned to a watershed and the population of steelhead occupying the watershed (Table 7-1 in National Marine Fisheries Service 2012c). These rankings provide an indication of the value of a coastal watershed for the conservation of the listed species – the Southern California steelhead DPS.
Value of the Santa Ynez River Watershed for the conservation of the listed species The findings of Boughton et al. (2006) indicate that only a few population units possess a high intrinsic potential of being viable and independent. The Santa Ynez River is one such population unit. Only 15 of the 50 steelhead population units in the DPS are ranked as a core-1 for recovery of this species and the 15 population units exist in the largest steelhead-bearing watersheds in southern California. The remaining population units are ranked as either core 2 (six units) or core 3 (30 units) and typically are found in smaller coastal watersheds. The action area
14Independent population: a collection of one or more local breeding units whose population dynamics or extinction risk over a 100-year time period is not substantially altered by exchanges of individuals with other populations (Boughton et al. 2006). 43 possesses a considerable amount of critical habitat relative to the total amount available throughout the Southern California steelhead DPS (National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)). Figure 2-1 illustrates the distribution of critical habitat in the Santa Ynez River and southern portions of the action area.
The following discussion in this sub-section illustrates the value of the Santa Ynez River steelhead population unit for the conservation of the species, highlighting the specific characteristics of this population that are essential to the recovery of the entire endangered Southern California steelhead DPS (National Marine Fisheries Service 2012c). These characteristics involve the independence of the Santa Ynez River population unit and its ability to persist in the face of environmental stochasticity, i.e., random changes in environmental conditions (Boughton et al. 2006).
Considered as an independent population when restored to an unimpaired condition, the Santa Ynez River population unit is expected to support formation and maintenance of several adjacent population units when recovered (Figure 2-2). This feature of the Santa Ynez River population unit effectively increases numbers of individuals in the broader population, thereby decreasing the risk of extinction for the entire Southern California steelhead DPS (Pimm et al. 1988, Primack 2004).
44 Figure 2-1.—Critical habitat designated in the Santa Ynez River and southern portions of the action area (source: National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)). ~ Santa Ynez Hydrologic Unit ,,"f,, ~ 3314
,
.'-. --.-.'11 f/ 7;)' ~ ... 1II-11t ..
f MlssionHilis (~ ... *. f.~ 1 331440 \ ........ 1t.. . .... (0 ,..,. ( , .... ~ ; l '/)CP IV i "'" rJ 331420 \ IlL I Los Olivos ( ,
< 33 '430 ,,4 ) to
331451 ,
..
..
• ••••••• • ". -.. . ... · -
.... , .. "
South Coast Hydrologic Unit
3315
o Citiesn-owns
Critical Habitat
Occupied but excluded streams I areas
:-_-___ '": Calwater Hydrologic Unit Boundary
~ ___ : Fifth Field Calwater Hydrologic Sul>-Area Boundary 331210 Fifth Field Calwater Hydrologic Sul>-Area Number 45 Figure 2-2.—Concept source-sink dynamic (after McElhany et al. 2000, Primack 2004). Circles represent habitats (e.g., watersheds) with size of the population unit and habitat capacity (large circles = source or core population units; small circles = sink or non-core population units). Shading represents population density: white=empty habitat, black=high density, and grey= intermediate density. Arrows indicate migration. In favorable years, source populations show relatively stable numbers and several sink populations show arrival of immigrants (A). Populations in sink areas may become extinct in unfavorable years (B), but sinks or non-core populations can be recolonized by migrants from source populations when conditions are favorable.
The Santa Ynez River population unit possesses two key ecologically significant attributes not found in most other population units within the Southern California DPS. First, the population unit constitutes a large percentage of the steelhead within the DPS and is found in one of the largest steelhead-bearing watersheds; the other three being the Santa Clara, Santa Maria, and Ventura rivers. The remaining units are small coastal populations, which by themselves do not appear sufficient to promote viability of the DPS (Boughton et al. 2006). Second, the Santa Ynez River population unit is an inland population, whereas the vast majority of population units are coastal. With longer migration routes, inland population units extend into areas that are drier and warmer than coastal units. Such environmental features promote diversity and specific lifehistory traits that favor steelhead survival (for evidence of variation in life history traits and adaptations to environmental characteristics, see review by Nehlsen et al. 1991). Historically, the inland populations of steelhead appeared to have been the largest within southern California particularly during favorable water years (Boughton et al. 2006, Boughton et al. 2007). 46 The independence of the Santa Ynez River population unit is closely tied to several important subpopulations of steelhead within the Santa Ynez River population unit.15 Prior to the construction of Bradbury, Gibraltar, and Juncal dams, steelhead ascended several sub-basins (Figure 2-3), and these sub-basins possess attributes that contribute to the independence of the Santa Ynez River population unit. These attributes must be represented and maintained to promote long-term viability of the species (Boughton et al. 2007). A review of these attributes follows:
First, many subpopulations are interior, requiring that steelhead have the physical ability to migrate long distances, an attribute that promotes population diversity and reduces extinction risk.
Second, interior subpopulations extend into an area that is drier and warmer than subpopulations closer to the coast; such environmental conditions would promote formation of specific adaptations that favor long-term survival of steelhead in stressful conditions.
Third, the subpopulations of Mono and Santa Cruz creeks, among major tributaries, represent some of the largest drainages (in terms of area) in the Santa Ynez River watershed. The extensiveness of these sub-basins, and their physical capacity to produce steelhead (Shapovalov 1944, Boughton 2013), contributes to their potential to support large populations of juvenile O. mykiss and, therefore, produce a large number of steelhead.
Fourth, many of the subpopulations are physically isolated within U. S. Forest Service lands, where anthropogenic activities are either not allowed or are restricted. As a result, the fishery resource and habitats are expected to be least impacted by human activities.
15 Key concepts in population theory are presented in this biological opinion, including a detailed discussion of the concepts at the beginning of section 2.2.2. Understanding these concepts is crucial for appreciating the importance of the subpopulations to the viability of the population unit (and likewise the value of the population units to the viability or independence of the DPS), and the relationship among steelhead abundance, habitat quality and quantity, fluctuations in environmental conditions, and extinction risk.
47 Figure 2-3.—Sub-basins in Santa Ynez River population unit that reportedly experienced influx of adult steelhead prior to the construction of Bradbury, Gibraltar, and Juncal dams (adapted from Alagona et al. 2012).
Fifth, the subpopulations still produce O. mykiss of native steelhead ancestry (Clemento et al. 2009, Garza and Clemento 2014) and an unknown number of these fish migrate from upstream of Bradbury Dam to downstream of the dam (Garza and Clemento 2007, 2014). This indicates a likelihood that individuals from certain sub-basins (e.g., Santa Cruz Creek subpopulation) still retain the ability to smolt and migrate to the ocean, consistent with other populations sequestered for several decades which are known to produce smolts that migrate to sea (Thrower et al. 2004a, b).
Lastly, because much of the sub-basins upstream of Cachuma Reservoir are expected to be perennial and within thermal tolerances for the species (Shapovalov 1944), even during dry years (Boughton 2013), the sub-basins would buffer the species against the effects of extended drought and climate change.
2.2.4 Natural environmental variability and climate change Natural environmental variability and climate change is expected to exacerbate the past and ongoing effects of anthropogenic effects on endangered steelhead and the amount and extent of properly functioning critical habitat for this species (National Marine Fisheries Service 2012c, 2016, Williams et al. 2016).
With regard to natural environmental variability, the existing climate of southern California can involve a long rainless season extending from May through November, and a brief rainy season from December through April (for the action area, cf. ESA PWA 2011). This region is subject to El Niño/La Niña weather cycles, which vary in occurrence from seven to ten years. This large‐scale weather pattern can significantly affect winter precipitation, causing highly variable 48 rainfall and significant changes in oceanic conditions between years. In addition to these temporal climatic patterns, there is wide disparity between winter rainfall from north to south, as well as between coastal plains and inland mountainous areas. River discharge, which creates and maintains freshwater habitat within southern California watersheds, is strongly influenced by the intra and inter‐annual pattern of short‐duration storms. As a result, river discharge varies greatly within and between seasons, and can be “flashy” during the winter, sometimes changing by several orders of magnitude over a few hours. Extended rain-free periods, which are fairly common in southern California, can lead to dramatic reductions in the amount and extent of surface flow during both the dry and wet seasons.
One factor affecting the range-wide status of the Southern California DPS of steelhead, and aquatic habitat at large, is climate change. Regarding the climate changes that have already been noted along the west coast of North America (National Marine Fisheries Service 2016), air temperatures have increased since the late 1800s, springtime snow-water equivalent has decreased over the last 60 years, and snowmelt is happening sooner in a given year. The drought in the southwest during the past 4 years is unprecedented in the historical record spanning 1,000 years. Tree mortality is widely observed throughout the southwest, and the frequency and amount of area burned by wildfire have increased.
With regard to the projected climate changes, National Marine Fisheries Service (2016) describes a number of changes are expected throughout the west coast of North America. The anticipated changes include spring snow cover declines of 7-25%, glacier recessions of 15-85%, sea surface temperature increases of 1.1-3.6°C, global sea level increases of 11-38 inches, and global ocean pH decreases of 38 to 109%, which correspond to a drop in pH of 0.14-0.32.
Lower elevation, more coastal or southern watersheds are expected to shift from consistent snowfall to alternating periods of snow and rain. Rain-dominated watersheds are likely to experience more intense precipitation events over shorter periods, and possible shifts in the timing of the most intense rainfall. Erosion and flooding in coastal areas are projected to increase with rising sea levels.
The projected climate changes, in combination with effects of ongoing land-use practices, are expected to cause changes in estuary dynamics. In particular, changes in depth and salinity are expected if increased sea level and upwelling are observed. A sea-level rise of 92 cm is forecasted for the coast of California by 2100. Generally, higher sea-surface temperatures and increased ocean acidity are predicted for marine environments, but regional marine impacts are expected to vary in relation to productivity. The historical and forecasted climate change has potential consequences for endangered steelhead.
Climate-driven changes to stream, estuarine and marine environments have the potential to significantly impact steelhead populations. Coupled with naturally stressful environments at the southern limit of the species distribution, multiple stressors are likely to be amplified by ongoing increases in temperature and changes in precipitation patterns (Mote et al. 2003, Hayhoe et al. 2004, see also National Marine Fisheries Service 2016 and Williams et al. 2016). When climate interacts with other stressors such as habitat fragmentation, additional threats to natural resources may emerge (McCarty 2001), including threats to the viability of steelhead populations. In particular, hydrologic connectivity allowing seasonal access to perennial, cool-water habitats at higher elevations, and a functioning estuary, will likely become more important to endangered salmonids seeking refuge from unsuitable temperature and streamflow (Crozier et al. 2008). 49 Increases in air temperature during summer are expected to increase evaporation and direct radiative heating. If water availability and storage decline in winter, warmer summer air temperatures are likely to further reduce already low minimum flows and raise maximum stream temperatures throughout many watersheds. The climate projections typically favor invasive fish species over native species, with declines of native species worsened by greater vulnerability of native species to ongoing effects of anthropogenic activities (National Marine Fisheries Service 2016).
Environmental monitoring data in the southwestern United States indicate changes in climatic trends have the potential to affect steelhead life history strategy and habitat requirements. The southwest region average annual temperature is projected to rise approximately 4° F to 10° F over the region by the end of the century (USGCRP 2009). Southern California is experiencing an increasing trend in droughts (USGCRP 2009), and Snyder and Sloan (2005) project mean annual precipitation in central western California will decrease by about 3-percent by the end of the century. Small thermal increases in summer water temperatures have resulted in suboptimal or lethal conditions and consequent reductions in O. mykiss distribution and abundance in the northwestern United States (Ebersole et al. 2001). Thus, climate variability will likely be an important factor in evaluating how the status of the species is influenced by changing climate.
Many of the foregoing climatic trends are likely to further degrade endangered steelhead oversummering habitat in southern California by reducing streamflows and raising stream temperatures (Katz et al. 2013). The increased air temperature has the potential to further limit areas that are thermally suitable for steelhead, particularly juvenile steelhead that rear all year in streams. Currently, much of the suitable rearing habitat for endangered steelhead in southern California lies upstream of introduced migration barriers, such as Bradbury Dam, and is therefore unavailable to the species. The over-summering areas that steelhead currently utilize below introduced migration barriers may become thermally limited or inhospitable as a result of climate change, further liming the availability of suitable living space for this species.
Impacts to steelhead may result in increased thermal stress even though this species has shown to tolerate higher water temperatures than preferred by the species as a whole (Spina 2007).
Conservation of existing steelhead populations will rely on identifying and providing unimpeded passage to the highest quality over-summering and spawning habitats, which would buffer habitat against changing climatic and hydrologic conditions. Habitat connectivity becomes as important as habitat quantity and quality when populations decrease and habitat is fragmented (Isaak et al. 2007).
Wildfire frequency, intensity, and extent are also important parameters to consider when considering a changing climate and associated impacts to steelhead and their habitat. Changes in vegetation communities for this region will likely include increases in the amount of grassland and decreases in most other major vegetation communities (e.g., chaparral, riparian woodland).
Wildfire risk in southern California was evaluated (Westerling and Bryant 2008), where the probability of large (>200-ha) fires ranged from a decrease of 29 to an increase of 28-percent.
The variation in range is due to the type of model used to make forecasts. Although wildfires can have long-term benefits for fish habitat (such as producing influxes of spawning gravels to the stream), in the short-term they can be catastrophic due to a variety of effects. These effects include: increasing erosion and subsequent deposition of fine sediments into streams that negatively affect steelhead spawning, foraging and depth refugia; destroying riparian vegetation that provides protective cover and thermal buffering (i.e., water temperature) along streams; and 50 facilitating the spread of non‐native plant and animal species.
Overall, the consequence of the natural variability and climate change, particularly when viewed against the backdrop of anthropogenic effects, is anticipated to include a reduction in population abundance, growth rate, diversity, and spatial structure of endangered steelhead, thereby driving the species closer to extinction.
2.3 Environmental Baseline
The “environmental baseline” includes the past and present impacts of all Federal, state, or private actions and other human activities in the action area, the anticipated impacts of all proposed Federal projects in the action area that have already undergone formal or early Section 7 consultation, and the impact of state or private actions which are contemporaneous with the consultation in process (50 CFR 402.02).
The presentation of the environmental baseline is organized into three principal categories: (1) status of steelhead in the action area, (2) status of designated critical habitat in the action area, and (3) threats to steelhead in the action area.
2.3.1 Status of Steelhead in the Action Area
Wild steelhead abundance, diversity, and spatial distribution have diminished throughout the action area as a result of anthropogenic activities, including in-channel habitat blockages and operation of water storage-diversion projects (Boughton et al. 2005, Williams et al. 2011, 2016, Alagona et al. 2012, National Marine Fisheries Service 2012c). Only small populations of steelhead remain in certain watersheds of the action area today. For example, the Santa Ynez River Watershed historically supported one of the largest, if not the largest, population of steelhead within the Southern California DPS numbering in thousands of adult steelhead annually returning to the river. Yet, recent monitoring (2001 through 2011) resulted in only 0 to 4 adult steelhead annually observed returning to the river, except in 2008 when a total of 16 adults were observed (National Marine Fisheries Service 2016).
In the Santa Ynez River portion of the action area, steelhead are currently limited to river reaches and tributaries downstream of Bradbury Dam, though prior to the construction of Gibraltar Dam in 1920, the species could access the entire watershed (Figure 2-4). Downstream of Bradbury Dam, Alisal Dam on Alisal Creek precludes steelhead from extensive areas of spawning and rearing habitats (Stoecker 2004). Within the southern portion of the action area, the construction of in-channel habitat obstructions, including exposed sections of the South Coast Conduit and road crossings, impede or preclude steelhead from a number of waterways and historical spawning and rearing habitats (Boughton et al. 2005, Cardno 2014, National Marine Fisheries Service 2014c).
2.3.2 Status of Designated Critical Habitat in the Action Area With regard to the status of designated critical habitat for steelhead in the action area, a variety of anthropogenic activities have diminished the amount, extent, and functional value of critical habitat (National Marine Fisheries Service 2012c). Diversion and retention of surface water alone has altered the timing, frequency, duration, magnitude, and rate-of-change of surface water in the action area, whereas the construction of road crossings (Boughton et al. 2005) and exposed pipeline crossings (i.e., South Coast Conduit) effectively impede or block steelhead from accessing historical waterways and spawning and rearing habitats (National Marine Fisheries Service 2014d). The loss of sediment due to dams and debris basins has significantly altered the 51 quality of habitat. The number of waterways that are accessible to steelhead today, and the ability of the accessible streams to support the life history and habitat requirements of this species, are greatly reduced compared to the historical, unimpaired condition (Boughton et al. 2006, National Marine Fisheries Service 2012c).
Figure 2-4. Portions of the Santa Ynez River watershed historically and currently available to steelhead (adapted from Alagona et al. 2012). Streams upstream of Bradbury Dam are no longer accessible to steelhead.
2.3.3 Threats to Steelhead in the Action Area
A number of anthropogenic threats directly and indirectly reduced the abundance, spatial distribution, and diversity of endangered steelhead within the action area. The existing and future conditions of natural-environmental variability and climate change discussed under Range-wide Status of the Species and Critical Habitat (subsection 2.2.4) applies to the action area (e.g., higher intensity rainfall-runoff events, reduced dry-season stream flow, and warmer dry-season stream temperature). Threats due to natural environmental variability and climate change have or are expected to worsen the man-made threats, which generally involve the effects of water development, land-use activities, and population growth and urbanization (National Marine Fisheries Service 2012c). Readers wishing greater detail on threats to the species are 52 directed to the source documents, including the Southern California Steelhead Recovery Plan (National Marine Fisheries Service 2012c and 2016 and references therein).
Although the southern portion of the action area is relatively small (approximately 2,000 feet of individual streams), we often present threats to steelhead in a broader context (e.g., effects of population growth, urbanization and land-use activities) because these activities can directly or indirectly affect the species and its habitat within the narrowly defined action area whether or not occurring within the action area.
Effects of water development
Development of surface-water resources dramatically altered the natural pattern and magnitude of streamflow throughout the action area. This is of concern because alteration to the natural streamflow regime represents one of the most critical threats to the survival of steelhead in southern California (National Marine Fisheries Service 2012c).
With regard to the types of water development, three major water projects capture and store river water within the Santa Ynez River watershed (Bradbury, Gibraltar, Juncal dams). Groundwater withdrawals and small surface-water diversions and at least two small reservoirs (Alisal Reservoir, and Glen Annie Reservoir) are numerous, and municipal use of water through the South-Coast Conduit is extensive (Bureau of Reclamation 2013a). Although Gibraltar and Juncal dams16 are physically outside (upstream) the action area, these dams trap and store surface water that would otherwise flow downstream into the action area. For this reason, the effects of operating these dams represent threats to the species in the action area and are considered here.
Recently identified as an exceedingly over-allocated surface-water resource in California (Grantham and Viers 201417, SBCCGJ 201618) the Santa Ynez River experienced radical alterations in the natural pattern and magnitude of streamflow, which continue this day (Shapovalov 1944, Bureau of Reclamation 2013a). Briefly, comparison of annual river hydrographs before development of major water projects in the basin (O’Dowd et al. 2014) show river discharge historically receded to high baseflows during late summer (e.g., 20 cfs near Lompoc) and year-round surface flows were common. An annual abundance of rainfall during the pre-dam period probably contributed to observing streamflow late into the dry season (cf.
Stetson Engineers 2016). By contrast, after major development of water resources river
16 Gibraltar Dam and reservoir are about 70 miles upstream from the ocean and were constructed in 1920 with Mission Tunnel for the purpose of diverting surface water from the Santa Ynez River through the Santa Ynez Mountains to Santa Barbara. Juncal Dam forms Jameson Lake about 90 miles upstream from the ocean and was constructed in 1930 with the Doulton Tunnel to divert water through the mountains to Montecito. 17 An extensive list of water-rights permits for the Santa Ynez River watershed can be obtained from the following link: https://ciwqs.waterboards.ca.gov/ciwqs/ewrims/EWPublicTerms.jsp 18 The Santa Barbara County Civil Grand Jury (SBCCGJ 2016) investigation found that water supply from Cachuma Reservoir is over allocated; annual allocation of water diverted from the reservoir for out-of-basin use (i.e., South Coast Conduit) does not adequately consider water-releases into the Santa Ynez River for maintaining downstream fish habitat, recharging downstream alluvial groundwater basins, or managing relative to annual reservoir inflow (e.g., spill-year versus subsequent non spill-years). For example, only two years following the last reservoir spill event (i.e., reservoir filled to capacity in 2011) the reservoir storage had already been reduced by 50% and reductions in water distribution did not occur until 2014 when Cachuma Reservoir storage was only 33% capacity. 53 0
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discharge recedes earlier in the year to considerably lower magnitudes and, with few exceptions19, flowing water is absent throughout summer and early fall.
Additional evidence of profound alterations in the pattern and magnitude of discharge in the Santa Ynez River involves comparisons of river hydrology before and after construction of Bradbury Dam (O’Dowd et al. 2014). This information reveals significant reductions in the frequency, duration, and magnitude of surface flows in the river downstream of the dam, shifts in the timing of peak flows, and increased rates of river recession (declining river discharge).
These alterations are consistent with the sorts of alterations reported for regulated river reaches downstream of dams (Poff et al. 1997) and water projects that capture and store river water primarily for agriculture and municipal purposes during the wet season with periodic releases during summer to downstream water users (Figure 2-5).
Smaller scale water projects are reported to reduce the amount and extent of surface flows in the action area. As early as 1906, observers report that water rights surpassed the availability of surface water in the lower Santa Ynez River (O’Dowd et al. 2014). The Alisal Guest Ranch and Resort operates the 100-acre Alisal Lake, formed from construction of an earthen dam on Alisal Creek. Streamflow that would otherwise contribute to the amount and extent of surface flow in the Santa Ynez River is captured and stored in Alisal Reservoir to support ranch and resort operations and related facilities including two 18-hole championship golf courses.
Figure 2-5. Inter-quartile range (25th, 50th and 75th percentiles) of the mean daily flow values (USGS gage 11126000) for the (A) pre and (B) post-Bradbury Dam flow regimes, Santa Ynez River.
Similar impacts have been reported for streams within the southern portion of the action area (National Marine Fisheries Service 2012c, National Marine Fisheries Service 2014). Many small surface-water diversions exist on streams that now or historically supported steelhead, and certain diversions are operated without consideration of steelhead life history and habitat
19 For instance, in the case of ephemeral 89-18 water releases from Bradbury Dam to the Santa Ynez River for delivery to downstream users typically during summer.
54 requirements. For instance, operation of the Cold Springs Tunnel on West Fork Cold Springs Creek is implicated in stranding and killing endangered steelhead (Sjovold 2013a, b, 2014).
Waning streamflow on Montecito Creek has occasionally prompted us, in collaboration with the California Department of Fish and Wildlife, to capture steelhead from shrinking instream areas and then relocate the fish to perennial reaches. Mission Tunnel takes water that would otherwise seep into Mission Creek, and the potential effects of this tunnel on endangered steelhead represent an ongoing concern (National Marine Fisheries Service 2009b).
Ongoing withdrawal of groundwater, principally within the Santa Ynez River portion of the action area (Shapovalov 1944, Bureau of Reclamation 2013a), represents another threat to steelhead. Four primary groundwater basins exist within the river valley, with annual reported production across all basins ranging from about 8,000 (1980) to 30,000 ac-ft (2002). In terms of effects, the local groundwater pumping can regularly reduce the volume of the groundwater basins, thereby increasing the potential to reduce if not eliminate surface flow in portions of the main-stem river connected to affected groundwater basins (ESA PW 2011, Barlow and Leake 2012). The Lompoc Plain Groundwater Basin is deliberately maintained in a dynamic state of equilibrium under State of California Water Resources Control Board decision WR 89-18. Loss of surface water in the portion of the main-stem river connected to this basin is fairly common, but basin recharge is augmented with periodic water releases (typically annually in late summer and early fall) from Bradbury Dam (Santa Barbara County Public Works Department Water Resources Division 2012).
Because the behavior, ecology, and survival of steelhead are inextricably linked to characteristics of the natural streamflow regime (Richter et al. 1996, Richter et al. 1997, Lytle and Poff 2004, National Marine Fisheries Service 2012c), alterations of the natural streamflow regime in the action area have adversely affected this species in a number of ways. These effects include an artificial reduction of migration opportunities for adults and juveniles, truncated access into the watershed and chances for spawning, and decreased prospects for establishing and maintaining essential over-summering habitat for juveniles (O’Dowd et al. 2014). The reductions in the amount and extent of streamflow are believed responsible for range-wide declines in steelhead abundance (Hedgecock et al. 1994, Moyle 1994).
Day-to-day operations of Bradbury Dam, including the Hilton Creek watering system, have on more than one occasion stranded and killed steelhead. In summer 2007, water releases from Bradbury Dam were insufficient to maintain surface flows near Alisal Bridge; the resulting conditions are suspect in the finding of three dead steelhead in a pool near the bridge (Robinson et al. 2007). The rapid release of large volumes of water owing to operations of Bradbury Dam in the winter of 2006 stranded juvenile steelhead (at least 12 mortalities were noted in the vicinity of Hilton Creek) (Bureau of Reclamation 2013a). In 2013 and 2014, multiple incidents related to the operation of the Hilton Creek watering system, including mechanical failures of water pumps and electrical power outages, were responsible for killing hundreds of fish in Hilton Creek (Bureau of Reclamation 2013a, b, Bureau of Reclamation 2014c). Reclamation subsequently repaired and replaced faulty pumps, upgraded the electrical system and installed an emergency backup system to avoid or reduce interruptions of the Hilton Creek water system.
However, a recent effort by Reclamation to use the emergency backup system pumps to supply water to Hilton Creek failed; the failure to start the water pumps was diagnosed as uncharged batteries supporting the diesel-powered generators (Bureau of Reclamation 2016a).
The capture and then storage of wet season river discharge upstream of Bradbury Dam has 55 affected historical features of the Santa Ynez River Estuary, with adverse consequences for endangered steelhead. The changes in the pattern and magnitude of river discharge reported for the river reduce inflow and frequency of smaller floods throughout downstream habitats and strongly influence the timing, frequency, and duration the estuary is open to the ocean (ESA PW 2011, O’Dowd et al. 2014). Because river entry and upstream migration of anadromous salmonids depends on the timing and duration of river connectivity with the ocean (Richter et al. 1996, Richter et al. 1997, Lytle and Poff 2004, Bond et al. 2008, National Marine Fisheries Service 2012c), the reduced timing, frequency, and duration of estuary-ocean connectivity decreases migration opportunities for steelhead throughout the watershed and the likelihood this species will complete its life cycle.
An unfortunate ecological consequence of water development in the action area involves the construction of dams that do not maintain passage of steelhead to historical spawning and rearing habitats, resulting in habitat fragmentation. Constructed without the requirement to uphold volitional passage of steelhead, Juncal, Gibraltar, and Bradbury dams block the species from historical spawning and rearing habitats in the watershed (Shapovalov 1944). Bradbury Dam alone blocks the species from more than two-thirds of the watershed and the bulk of spawning and rearing habitats (Figure 2-6), and no doubt reduces the rate at which O. mykiss emigrants upstream of the dam contribute to the listed DPS. Reducing the availability of spawning and rearing habitats is expected to translate into declines in fish population abundance and spatial structure within the action area (Nehlsen et al. 1991, Rieman and McIntyre 1995, Neraas and Spruell 2001, Rieman and Allendorf 2001, Morita and Yamamoto 2002), which increases the risk of species extirpation in the action area.
56 Figure 2-6. Estimated amount and extent of spawning and rearing areas for steelhead in the Santa Ynez River watershed (source: Boughton and Goslin 2006). Streams upstream of Bradbury Dam are no longer accessible to steelhead. The amount of habitat lost is about 455 miles (63%).
Another consequence of dams in the action area involves geomorphic changes on downstream habitats that translate into negative effects on stream fish (Ligon et al. 1995, Kondolf 1997, Trush et al. 2000). These changes can include coarsening of the river bed (winnowing of sand, gravel, and small cobble from the river bed), halting the development of mid-channel bars and islands, eliminating spawning areas, simplifying instream habitat for fish, creating “habitat bottlenecks” that limit abundance of anadromous salmonids, channel incision and decreased inundation of the floodplain, encroaching riparian vegetation into the stream channel, and filling pools with fine sediments. With regard to Bradbury Dam, the combined effects of reduced sediment discharge (Willis and Griggs 2003, Slagel and Griggs 2008) and diminished frequency of peak flows (Figure 2-7) disrupt natural reworking of the river channel and floodplain, and have led to decreased number and volume of pools, and habitat capacity for juvenile steelhead (Harrison et al., in revision). All of the coarse sediment produced by the Santa Ynez River watershed upstream of the dam is trapped in the reservoir, and this sediment is the foundation for habitat forming and maintenance processes downstream extending to the ocean. About 75% of all floods that began upstream from the dam did not reach the river valley (O’Dowd et al. 2014). 57 1 2 5 10 20 50 100
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Figure 2-7. Flood-frequency curves for the pre- and post-Bradbury Dam streamflow regimes on the Santa Ynez River (USGS gage 11128500). Open circles on each line indicate flow values that have a probability of occurring once every 2, 5, or 10 years.
Effects of land-use activities
Land use in the action area considered here involves agriculture, gravel mining, and military operations at Vandenberg Air Force Base (National Marine Fisheries Service 2012c, Bureau of Reclamation 2013a).
Agriculture, principally involving cattle grazing and cropland, are reported for the action area (Bureau of Reclamation 2013a) and, when undertaken in a manner that damages steelhead habitat, can represent a threat to the survival and recovery of endangered steelhead (National Marine Fisheries Service 2012c). Within the broad action area, agriculture is primarily confined to the Santa Ynez River portion; cropland is limited to the river floodplain, whereas cattle grazing is widespread within the main stem Santa Ynez River and tributaries (e.g., Salsipuedes Creek). The potential effects of these activities can include a reduction in the availability and quality of habitat for endangered steelhead owing to increased input of sand and smaller particles to waterways, loss or reduction in the amount of streamside vegetation, and input of harmful chemicals (Hicks et al. 1991, Platts 1991, Wohl and Carline 1996).
With regard to the aggregate mining in the action area, primarily the Santa Ynez River portion, our interaction with gravel miners in the valley indicate discrete portions of the river channel are mined such that impacts on steelhead habitat are minor. We therefore do not expect the creation of relatively deep excavations and broadly simplified reaches (shallow channel) that may strand steelhead when elevated river discharge receded, or challenge migration of this species during low winter baseflows (McGoogan 2014).
Occupying about four percent of the Santa Ynez River watershed, Vandenberg Air Force Base exists in the lower portion of the watershed, overlapping extensively with the river and estuary in 58 this regard. Although military activities can create effects to water-dependent species and their habitats (Quist et al. 2003), we have found no information describing effects, if any, on endangered steelhead resulting from military activities undertaken on Vandenberg Air Force Base.
Effects of population growth and urbanization
Our presentation of the threats to steelhead due to population growth and urbanization is largely confined to the southern portion of the action area because known threats owing to these activities are primarily confined to this portion. We first briefly describe the underlying mechanism for the growth and urbanization, then transition to consequences for endangered steelhead and designated critical habitat.
The development of major-water projects in the action area had subsequent consequences for population growth and urbanization. Building Gibraltar Dam doubled the county population (WDSC 1947), whereas the Cachuma Project allowed for an explosive population growth (SFNB 1961, CEC 1972) resulting from benefits to domestic, agricultural, and industrial water requirements of the already rapidly growing south-coast area (Bureau of Reclamation 1947, Department of Planning 1951, Bureau of Reclamation 1956). Completion of the Project provided the chief source for both domestic and irrigation water in the south-coastal strip from Ellwood to the Ventura County line (Bureau of Reclamation 1950, SBCPC 1953).
The driver for a greater source of water was 30,000 new county residents between 1920 and 1940 (McCleery 1981). From 1900 to 1960, the first 30 years of growth was fairly steady, while the last 20 years accelerated by post-war expansion and the Project (City of Santa Barbara 1963).
Growth in any locality requires resources; for the south-coast portion of the action area, the Project provided the resources necessary for growth (SBCWA 1949). The Project would not only amply provide for population growth over many years, but cause millions of dollars to be spent in Santa Barbara County, thereby benefiting the county economy (Citizens’ Committee for Cachuma Water 1948).
Water resource development can induce population growth (Ahlroth and Almy 1991); the Santa Barbara County Water Agency assumed leadership in water supply development by proposing the program of water resource planning (e.g., additional surface reservoir construction on the Sisquoc River, Salsispuedes Creek, and through raising of Cachuma Dam) since the demands for water equaled or exceeded the safe yields of presently developed water supplies (SBCWA 1974, 1979). Water supply alternatives (e.g., import State Water Project water and develop additional water resources) would induce growth, both by increasing growth rates and by increasing the population holding capacity of the County (SBCWA 1979). In the most recent decade, the population grew by just 0.6 percent (CEF 2012).
The extensive urbanization led, in part, to conversion of land to impervious surfaces and creation of extensive transportation and conveyance infrastructure and urban centers, particularly in the southern portion of the action area (National Marine Fisheries Service 2012c, Bureau of Reclamation 2013a). The widespread urban centers and related infrastructure extensively overlap with endangered steelhead and designated critical habitat for this species. In the paragraphs that follow, we summarize the consequences of the urban overlap for the species.
The construction of transportation and conveyance projects notably reduced the availability and quality of habitat for endangered steelhead. Introduced migration barriers, including improperly 59 designed road crossings and debris-basin dams, impede or fully exclude adult steelhead from accessing several miles of historical spawning and rearing habitats within individual waterways (Boughton et al. 2005, National Marine Fisheries Service 2014). The South-Coast Conduit crosses several streams in the action area and certain crossings impede or block upstream migrants (Stoecker 2002, Cardno 2014).
Urbanization in and near the southern portion of the action area has led to extensive encroachment upon waterways that are essential for steelhead survival and recovery (National Marine Fisheries Service 2012c). Positioning of features commonly associated with urban centers (e.g., homes, roads, hard-banking structures) preclude streams from naturally migrating laterally or accessing natural flood plains, both of which can reduce habitat complexity for endangered steelhead. The encroachment has led to extensive loss of the original boundary of the riparian corridor throughout much of the southern portion of the action area, which is considered an adverse effect given the value of streamside vegetation to habitat form and function, and growth and survival of stream-fish populations (Murphy and Meehan 1991).
Along with urbanization comes the perceived need to control streams and increase flood conveyance, which in turn can create a host of harmful effects for water-dependent species (Brookes 1988), including steelhead. In this context, Santa Barbara County’s Flood Control District (District) undertakes a number of stream-maintenance activities in the southern portion of the action area, which are harmful to endangered steelhead and designated critical habitat for this species (National Marine Fisheries Service 2014d).
The District’s activities include channelization, vegetation clearing from within stream channels, maintenance and operation of several in-channel debris basins, grade-control structures, and concrete-lined channels, and removal of woody debris and coarse sediment from streams. These activities have led to widespread and profound reductions in the function, amount, and extent of habitat for endangered steelhead within and adjacent (upstream and downstream) to the southcoast portion of the action area. These effects to the species are expected to be remediated owing to the Reasonable and Prudent Alternative included in our 2014 biological opinion (National Marine Fisheries Service 2014d), which is designed to meet the flood-control needs of the District while at the same time ensuring that flood-control activities do not jeopardize the likelihood of survival and recovery of endangered steelhead nor adversely modify or destroy designated critical habitat.
Although we lack specific information on the effects of runoff from urban centers in the action area on endangered steelhead and habitat for this species, a few generalizations can be gleaned from the scientific literature. Conversion of lands to impervious surfaces can increase the rate that nitrogen and sand and smaller particles enter surface waters, leading to reduced habitat quality and abundance of desirable aquatic species, and increased eutrophication of receiving waters (Weaver and Garman 1994, Bowen and Valiela 2001, Quist et al. 2003). Consequently, land development and the proliferation of urban areas, observed principally within the southern portion of the action area, generate runoff that is potentially harmful to steelhead.
Land development in the action area reduced the size and quality of estuaries (ESA PW 2011, National Marine Fisheries Service 2012c). Bridge construction and abutments physically altered the Santa Ynez River Estuary, with the principal effects involving simplification of the channel morphology and reduced meander (ESA PW 2011). The loss of estuarine habitat quality and quantity within the action area is of concern because estuary habitat is a physical or biological 60 feature of critical habitat designated for the Southern California steelhead DPS (National Marine Fisheries Service 2005, National Marine Fisheries Service 2012c).
2.4 Effects of the Action
Under the ESA, “effects of the action” means the direct and indirect effects of an action on the species or critical habitat, together with the effects of other activities that are interrelated or interdependent with that action, that will be added to the environmental baseline (50 CFR 402.02). Indirect effects are those that are caused by the proposed action and are later in time, but still are reasonably certain to occur.
This consultation considers the effects of the operation and maintenance of Bradbury Dam on the endangered Southern California DPS of steelhead and designated critical habitat for this species.
We note the proposed action stipulates that Bradbury Dam maintenance activities will be conducted as needed based on annual evaluations of the dam “structural integrity” (e.g., page 2- 15, Bureau of Reclamation 2013a). Therefore, the proposed maintenance activities are for the purpose of preserving the physical capabilities of Bradbury Dam to capture and hold incoming river discharge, and incidentally sediment and organic debris, consistent with the intended purpose and design of the dam. As a result, in this biological opinion we classify the effects due to the continued existence of Bradbury Dam on designated critical habitat and endangered steelhead as indirect effects of the proposed action. However, we are treating the past and present impacts of the presence of Bradbury Dam as part of the environmental baseline.
As a matter of clarification, when classifying effects due to the continued presence of Bradbury Dam as indirect effects of the proposed action, we are not necessarily presuming that the dam would not be present but for the proposed action. Rather, we are highlighting the issue that the proposed maintenance activities provide a level of enhancement or preservation to the operation of the dam to catch and store water over time consistent with the purpose and design of the structure that would otherwise not be achievable if not for the proposed action. In a situation involving an unmaintained dam, the functional longevity for such a structure, consistent with the intended purpose of the dam, cannot be assured and is unspecified. Further, the operational volume and capability of an unmaintained dam for capturing and then storing a pre-defined proportion of river discharge, commensurate with the original design of the structure, cannot be guaranteed. In addition, because the future effects due to the continued presence of Bradbury Dam cannot be meaningfully separated from the effects of future operations and maintenance, all such future effects are analyzed as “effects of the action.”
2.4.1 Effects of the Action on Critical Habitat
In this section we analyze the expected effects of the proposed action on designated critical habitat for endangered steelhead due to (1) operating Bradbury Dam-Cachuma Reservoir, (2) maintaining Bradbury Dam, (3) monitoring habitat conditions in the Santa Ynez River and selected tributaries downstream of Bradbury Dam, and (4) operating and maintaining the SouthCoast Conduit. Designated critical habitat affected by the proposed action includes about 45 miles of the Santa Ynez River from Bradbury Dam downstream to the estuary20, 0.5 miles of
20 The Santa Ynez River estuary is within lands owned or controlled by the Department of Defense (i.e., Vandenberg Air Force Base) and excluded from designated critical habitat (National Marine Fisheries Service (70 FR 52488, September 2, 2005)).
61 Hilton Creek (Santa Ynez River Watershed), and locations where the South Coast Conduit intersects coastal stream designated critical habitat.
2.4.1.1 Effects on Critical Habitat due to Operating Bradbury Dam Our analysis of the effects due to proposed operation of Bradbury Dam begins with the effects of the action on the pattern and magnitude of river discharge, and natural habitat-forming processes.
Establishing these effects is essential to predict the effects of the action on designated critical habitat (and endangered steelhead) because the natural movement of water, sediment and organic material creates and maintains physical or biological features of critical habitat designated for the Southern California steelhead DPS. With these effects in mind, we then transition into a description of the expected effects of the proposed operation, maintenance, and monitoring on designated critical habitat for endangered steelhead. Because the proposed operation of Bradbury Dam (i.e., capture, storage and managed release of water, including managing alluvial groundwater at depleted levels) is the same or similar to the operations that have existed for at least the last 8 years, we often characterize effects of the action as “extending the effects of the existing operations into the future” (or similar phrase). We will first describe the hydrologic and geomorphic contexts for the continued effects of the proposed action on the pattern and magnitude of river discharge. We will then describe the anticipated effects on the physical or biological features of critical habitat designated for the Southern California steelhead DPS that are predicted to be impacted.
Continue to alter the pattern and magnitude of discharge in the Santa Ynez River To predict the effects of the proposed action on the pattern and magnitude of river discharge, our analysis considers that the proposed action would continue effects of the existing project operations on river discharge. In this regard, our analysis compares river discharge (1) without the influence of the existing Cachuma project operations21 (but with the influence of Gibraltar Dam operations) (termed “Without Current or Proposed Bradbury Dam Operations”), (2) with the influence of the existing Cachuma project operations (and influence of Gibraltar operations) (“Current Operation”), and (3) as expected under the proposed action (and influence of Gibraltar operations) (“Proposed Operation”). This approach adequately predicts the hydrologic effects that would be perpetuated under the proposed action, as described more fully below.
To perform this analysis, we utilized Santa Ynez River daily mean discharge at the USGS gaging station near Solvang, CA (11128500) because of the proximity of this gage to Bradbury Dam (about 10-miles downstream), availability of continuous data for the period representing current and proposed Bradbury Dam operations, and relevance to Reclamation’s own effects assessment for this consultation (i.e., adult steelhead passage opportunities). Water years 2006 through 2013 were selected for this analysis because this period of record represents Reclamation’s current operations of Bradbury Dam (i.e., full implementation of operation criteria since issuance of the September 2000 biological opinion) and most accurately characterizes river discharge under Reclamation’s proposed action, including the influence of the proposed flow-related measures to minimize adverse effects on steelhead and designated critical habitat.
21 For purposes of this analysis, “without the influence of the existing Cachuma project operations” projects natural discharges in the Santa Ynez River downstream of Bradbury Dam. That is, river discharge absent of capture and storage at Bradbury Dam, winter storm operations, and water-rights releases. 62 Having performed this analysis, the findings are consistent with those of other investigators (e.g., O’Dowd et al. 2014) and indicate that the proposed operation of Bradbury Dam will continue to profoundly alter the magnitude, duration, frequency, rate-of-change, and timing of discharge in the river downstream of the dam (Figures 2-8 through 2-11). As an overview of our findings, the proposed action would continue to reduce and, in certain cases, eliminate the magnitude and duration of discharge pulses (i.e., rain-induced periods of elevated streamflow) during winter and spring. Findings from the hydrologic analysis indicate annual maximum daily mean discharge would continue to be reduced in all types of water years (Table 2-2 and Figure 2-12), perhaps by as much as eighty-five percent (e.g., water year 2008). Likewise, the daily average magnitude and duration of discharge pulses are projected to remain reduced in all types of water years. The median daily mean discharge during winter and spring would remain reduced in wetter years (e.g., 2006, 2008, 2010 and 2011) though no change is forecasted for drier years (Figure 2-12).
An occasional shift in the timing of the peak maximum river discharge from the wet season to the dry season is expected owing to the proposed action.
In addition to the effects perpetuated under the proposed action on the pattern and magnitude of river discharge downstream of Bradbury Dam is the effect of the interrelated action, the Upper Santa Ynez River Operations Agreement. Under this proposed agreement (i.e., contract), Reclamation would obligate additional Santa Ynez River water captured and stored by Bradbury Dam for out-of-basin delivery to municipal and agricultural users. In addition to the approximate 25,700 ac-ft of water under the proposed action, up to 8,567 ac-ft of water would be annually diverted from the Santa Ynez River. Because the actual volume of water annually captured and stored by Bradbury Dam would not change under this agreement (Bureau of Reclamation 2013a), the effect is incorporated in the following analysis as part of the total river water stored in Cachuma Reservoir. Although this agreement would not change the amount of water captured in the reservoir, this interrelated action is expected to exacerbate the effects resulting from the proposed action on river discharge downstream of the dam because more water would be diverted out-of-basin via the Tecolote Tunnel-South Coast Conduit and less water would be available for releasing into the Santa Ynez River. 63 Figure 2-8. Daily mean discharge in the Santa Ynez River at Solvang, CA during water years 2006 and 2007 for three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). The river discharge representing “Without Current or Proposed Bradbury Dam Operations” was calculated by adding Cachuma Reservoir inflow (i.e., combined discharge measured at USGS gaging stations 11123500—Santa Ynez River below Los Laureles Canyon Creek and 11124500—Santa Cruz Creek) to the estimated river discharge at USGS gage 11128500—Santa Ynez River at Solvang, CA without releases from Bradbury Dam (i.e., measured discharge at Solvang minus reported water releases from Bradbury Dam).
64 Figure 2-9. Daily mean discharge in the Santa Ynez River at Solvang, CA during water years 2008 and 2009 for three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). The river discharge representing “Without Current or Proposed Bradbury Dam Operations” was calculated by adding Cachuma Reservoir inflow (i.e., combined discharge measured at USGS gaging stations 11123500—Santa Ynez River below Los Laureles Canyon Creek and 11124500—Santa Cruz Creek) to the estimated river discharge at USGS gage 11128500—Santa Ynez River at Solvang, CA without releases from Bradbury Dam (i.e., measured discharge at Solvang minus reported water releases from Bradbury Dam).
65 Figure 2-10. Daily mean discharge in the Santa Ynez River at Solvang, CA during water years 2010 and 2011 for three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). The river discharge representing “Without Current or Proposed Bradbury Dam Operations” was calculated by adding Cachuma Reservoir inflow (i.e., combined discharge measured at USGS gaging stations 11123500—Santa Ynez River below Los Laureles Canyon Creek and 11124500—Santa Cruz Creek) to the estimated river discharge at USGS gage 11128500—Santa Ynez River at Solvang, CA without releases from Bradbury Dam (i.e., measured discharge at Solvang minus reported water releases from Bradbury Dam).
66 Figure 2-11. Daily mean discharge in the Santa Ynez River at Solvang, CA during water years 2012 and 2013 for three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). The river discharge representing “Without Current or Proposed Bradbury Dam Operations” was calculated by adding Cachuma Reservoir inflow (i.e., combined discharge measured at USGS gaging stations 11123500—Santa Ynez River below Los Laureles Canyon Creek and 11124500—Santa Cruz Creek) to the estimated river discharge at USGS gage 11128500—Santa Ynez River at Solvang, CA without releases from Bradbury Dam (i.e., measured discharge at Solvang minus reported water releases from Bradbury Dam).
67 Table 2-2. Annual maximum daily mean discharge in the Santa Ynez River at Solvang, CA during water years 2006 through 2013 for three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria).
WY 2006 WY 2007* WY 2008 WY 2009
Date Discharge Date Discharge Date Discharge Date Discharge Proposed
Operation
4/5/06 11,200 7/25/07 143 1/27/08 1,890 2/16/09 106
Current
Operation
4/5/06 11,200 7/25/07 143 1/27/08 1,890 2/16/09 106
Without
Operations
4/4/06 13,946 2/23/07 20 1/27/08 12,978 2/18/09 352
WY 2010 WY 2011 WY 2012 WY 2013*
Date Discharge Date Discharge Date Discharge Date Discharge Proposed
Operation
1/21/10 607 3/21/11 11,100 4/14/12 18 7/26/13 129
Current
Operation
1/21/10 607 3/21/11 11,100 4/14/12 17 7/26/13 129
Without
Operation
1/21/10 2,847 3/20/11 21,114 4/13/12 103 12/24/12 52
*Maximum daily mean discharge in water years 2007 and 2013 for the proposed and current operations was not associated with rainfall events, rather these pulses resulted from Bradbury Dam water releases for the purpose of recharging depleted Santa Ynez River alluvial groundwater basins. 68 Figure 2-12. Comparison of maximum and median daily mean discharge in the Santa Ynez River at Solvang, CA during the principal migration period (January through May) of water years 2006 through 2013 for three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria).
69 To further assess potential effects of the proposed action on the duration of elevated streamflow associated with discharge pulses, we calculated the cumulative days between January 1 and May 31 with a daily mean discharge at or above an assigned threshold (i.e., 25 cfs) (Figure 2-13). We selected a daily average discharge threshold of 25 cfs for two reasons: first, the hydrologic data indicates streamflow ≥ 25 cfs can be associated with rainfall-induced discharge pulses; and secondly, this discharge value corresponds with Reclamation’s identified minimum-passage flow for steelhead relative to streamflow at Solvang. The results from this inquiry indicate the proposed action will continue to appreciably reduce the duration of elevated streamflow in the Santa Ynez River, and corroborate similar findings (e.g., Figures 2-9 and 2-10). The estimated reduction in duration of streamflows ≥ 25 cfs resulting from the proposed action ranged from 32 to 48 percent during wetter years (2006, 2008, 2010, and 2011). Although drier years are generally presumed to provide elevated streamflow of limited duration, the cumulative days at or above the assigned threshold of 25 cfs for water year 2009 (a dry year) was reduced from 48 days to 3 days.
Upon closer inspection of individual water years, our analyses confirm that certain individual discharge pulses are likely to be eliminated by the proposed operations in both wet and dry water-year types (e.g., Figures 2-14 and 2-15). Eliminating discharge pulses translates into disrupting the timing and reducing the frequency of discharge pulses in the Santa Ynez River below Bradbury Dam.
Figure 2-13. Comparison of cumulative days when daily mean discharge was greater than or equal to 25 cfs in the Santa Ynez River at Solvang, CA, between January 1 and May 31, under three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). In water year 2007, the daily mean discharge was <25 cfs for the selected period under all three conditions. 70 Figure 2-14. Daily mean discharge in the Santa Ynez River at Solvang, CA occurring from February 15, 2011 through March 15, 2011, representing an example discharge pulse under three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). Because the current and proposed operations are essentially the same, these lines overlap and appear as a single line.
Figure 2-15. Daily mean discharge in the Santa Ynez River at Solvang, CA occurring from March 10, 2012 through May 10, 2012, representing an example discharge pulse under three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). 71 In addition to reducing the magnitude, duration and frequency of Santa Ynez River discharge, our finer grained hydrologic analyses confirm that the proposed operations would continue to increase the rate of river recession downstream of Bradbury Dam (i.e., the rate that river discharge is reduced). Among other consequences, increasing the rate of river recession would preclude or appreciably reduce discharge pulses that would otherwise be contributed by the Santa Ynez River upstream of Bradbury Dam, and functionally eliminate (e.g., Figures 2-14 and 2-15) or truncate discharge pulses downstream (Figure 2-16). Furthermore, artificial flow pulses resulting from the proposed operations at Bradbury Dam during the summer represent an alteration in the rate, and thus rate of change, in discharge relative to what would be expected without proposed or current operations (e.g., Figure 2-8 for water year 2007, and Figure 2-11 for water year 2013).
Figure 2-16. Daily mean discharge in the Santa Ynez River at Solvang, CA occurring from February 10, 2009 through April 30, 2009, representing an example discharge pulse under three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). Because the current and proposed operations are essentially the same, these lines overlap and appear as a single line.
The proposed action incorporates criteria for deliberately operating Bradbury Dam to maintain downstream alluvial groundwater basins at deficit levels (e.g., Santa Ynez River alluvial groundwater basin at 10,000 ac-ft of dewatered storage), increasing percolation of Santa Ynez River and tributary inflow below the dam (SWRCB 1973). Because the alluvial groundwater basin is in direct hydraulic communication with surface flow of the river (Gibbs 2011), decreasing groundwater levels and increasing percolation can reduce or eliminate surface flow as demonstrated in the lower Santa Ynez River (O’Dowd, et al. 2014) and tributaries such as Zanja de Cota Creek (Singer 1979). Although Reclamation’s water-rights permits require releasing water from Bradbury Dam for the purpose of recharging the Santa Ynez River alluvial groundwater basins, the combined effect of capturing and storing river discharges behind the dam and delaying releases until after extensive groundwater depletion has occurred is expected 72 to artificially reduce the duration and spatial extent of surface flow in the river downstream of the dam.
One last way the proposed action would affect the pattern and magnitude of river discharge involves winter-storm operations. Reclamation proposes that water levels in Cachuma Reservoir would be reduced before and during rainfall events to avoid or moderate downstream flooding.
Specifically, when rainfall predictions exceed 20,000 ac-ft of inflow to the reservoir, Reclamation would release water from the reservoir (1) 12 to 48 hours in advance of the predicted storm to increase available storage in the reservoir, (2) at a rate equivalent to inflow during the early portion of the storm to maintain reservoir below operating level, or (and) (3) operating spillway gates to detain a portion of the storm-peak inflow in Cachuma Reservoir and reduce the rate of outflow.
While information about the proposed winter-storm operations are limited, we are able to inform a few general expectations. The winter-storm operations have the potential to artificially and rapidly increase and decrease the magnitude of river discharge downstream of Bradbury Dam.
Rapid increases and decreases are probable because such were observed in the winter 2006 (Figure 2-17) and 2011. These rapid fluctuations in river discharge, particularly when in close succession as in 2006, can adversely affect physical or biological features of critical habitat designated for the Southern California steelhead DPS. For example, juvenile or adult steelhead mobility may be altered causing displacement from a high-velocity discharge pulse or stranding when discharges rapidly recedes, adversely affecting the freshwater migration corridor and rearing sites (e.g., winter-storm operations of 2006 resulted in the stranding and death of at least 12 juvenile steelhead (Payne and Robinson 2007)). Another example is when steelhead spawning occurs during winter-storm operations, nests could be destroyed by high-discharge pulses scouring the channel bed or subject to desiccation following rapid decline of the discharge pulse.
73 Figure 2-17.— Comparison of the rate of inflow to Cachuma Reservoir versus the rate of water released into the Santa Ynez River downstream of Bradbury Dam for winter-storm operations during winter 2006 (source:
Shahroody and Lawler 2010).
Continue to disrupt natural habitat-forming processes in the main-stem river downstream of Bradbury Dam
The natural movement of organic debris, sediment and water in rivers is integral to the formation of complex and abundant habitats that water-dependent species require for fulfilling life-history function (Poff et al. 2007). However, the proposed action would continue disruption of natural habitat-forming processes in the downstream habitats. In particular, the proposed action will preserve the ability of Bradbury Dam to (1) capture and store sediment and water, (2) regulate river discharge, (3) reduce the magnitude and frequency of most channel-shaping flows (e.g., O’Dowd et al. 2014), and (4) reduce the delivery of coarse bed material to the lower main stem.
These impacts translate into adverse geomorphic effects (e.g., Ligon et al. 1995, Kondolf 1997, Trush et al. 2000) that are well established for Bradbury Dam.
For instance, we know the combined effects of reducing sediment discharge (Willis and Griggs 2003, Slagel and Griggs 2008) and diminished frequency of peak (or flood) flows (Figure 2-7) (O’Dowd et al. 2014) have disrupted the formation and periodic reworking of the river channel and floodplain, and decreased the number and volume of pools and capacity of the habitat to support juvenile steelhead (Harrison et al., in revision). Additionally, Table 2-3 describes 74 alluvial river attributes associated with properly functioning riverine-habitat characteristics and conditions and related effects of the proposed action in the Santa Ynez River downstream of Bradbury Dam. These adverse effects would persist because Reclamation proposes to neither remediate the effects nor promote natural habitat-forming processes through, for example, sediment augmentation or flushing flows.
75 Table 2-3. Alluvial river attributes (sensu Trush et al. 2000) associated with properly functioning riverinehabitat characteristics and conditions and related effects of the proposed action in the Santa Ynez River downstream of Bradbury Dam.
Attribute description Related effect of the proposed action
1. —The primary geomorphic and ecological unit of an alluvial river is the alternate bar sequence.—Dynamic alternating bar sequences are the basic structural underpinnings for aquatic and riparian communities in healthy alluvial river ecosystems.
Proposed operations would continue to diminish the
frequency of flood flows downstream of Bradbury Dam,
reducing natural rates of channel-bed mobilization and
deposition.
2.—Each annual hydrograph component accomplishes specific geomorphic and ecological functions.—Annual hydrograph components (including winter storm events, baseflows, snowmelt peaks, and snowmelt recession limbs) collectively provide the impetus for processes that shape and sustain alluvial river ecosystems. These components are uniquely characterized by year-to-year variation in flow magnitude, duration, frequency, and timing.
Proposed operations would continue to profoundly alter the pattern and magnitude of river discharge, reducing natural inter-annual variation in river discharge.
3.—The channelbed surface is frequently mobilized.—Coarse alluvial channelbed surfaces are significantly mobilized by bankful or greater floods that generally occur every 1-2 years.
Proposed operations would continue to diminish frequency of flood flows downstream of Bradbury Dam, reducing natural rates of channel-bed mobilization and deposition.
4.—Alternate bars must be periodically scoured deeper than their coarse surface layers.—Floods that exceed the threshold for scouring bed material are needed to mobilize and rejuvenate alternate bars. Alternate bars are periodically scoured deeper than their coarse surface layer, typically by floods exceeding 5- to 10-year annual maximum flood recurrences. Scour is generally followed by redeposition, often with minimal net change in the alternating bar topography.
Proposed operations would continue to diminish the
frequency and magnitude of flood flows downstream of
Bradbury Dam, reducing natural rates of channel-bed
mobilization and deposition.
5.—Fine and course sediment budgets are balanced.—River reaches export fine and coarse sediment at rates approximately equal to sediment input rates.
Proposed operation of Bradbury Dam would continue
trapping fine and coarse sediment, reducing sediment
discharge downstream.
6.—Alluvial channels are free to migrate.—During lateral migration, the channel erodes older flood plain and terrace deposits on the outside bend whereas it deposits sediment on the bar and flood plain of the inside bend.
Although outer and inner bend processes may be caused by different hydrograph components, the long-term result is maintenance of channel width.
Proposed operations would continue to diminish the
frequency and magnitude of flood flows downstream of
Bradbury Dam, disrupting natural processes that promote channel migration.
7.—Flood plains are frequently inundated.—Flood plain inundation typically occurs every 1-2 years. Flood plain inundation attenuates flood peaks, moderates alternate bar scour, and promotes nutrient cycling.
Proposed operations would continue to diminish the
frequency and magnitude of flood flows downstream of
Bradbury Dam, reducing natural rates of floodplain
inundation.
8.—Large floods create and sustain a complex mainstem and flood plain morphology.—Large floods – those exceeding 10- to 20-year recurrence events – reshape and/or redirect entire meander sequences, avulse mainstem channels, rejuvenate mature riparian stands to early successional stage, form and maintain side channels, scour flood plains, and perpetuate off-channel wetlands including oxbows.
The proposed operations would continue to the diminish
frequency and magnitude of flood flows, reducing natural rates of channel mobilization and habitat-forming processes.
9.—Diverse riparian plant communities are sustained by the natural occurrence of annual hydrograph components.—Natural, interannual variability of hydrograph components is necessary for woody riparian plant life history strategies to perpetuate early and late successional stand structures.
Proposed operations would continue to alter the natural interannual variability in magnitude and duration of river discharge downstream of Bradbury Dam, disrupting the
complex interaction between hydrology and riparian plant succession.
10.—Groundwater in the valley bottomlands is hydraulically connected to the mainstem channel.—When flood plains are inundated, a portion of surface runoff from the watershed is retained as groundwater recharge in the valley bottomlands.
Proposed operations would continue to diminish the
frequency, magnitude and duration of flood flows
downstream of Bradbury Dam, disrupting natural rates of floodplain inundation and groundwater recharge.
76 The foregoing establishes the hydrologic and geomorphic contexts for the continued effects of the proposed action on the pattern and magnitude of river discharge. We now move to a description of the anticipated effects on the physical and biological features of designated critical habitat for endangered steelhead that are predicted to be impacted: (a) freshwater migration corridor, (b) freshwater spawning sites, and (c) freshwater rearing sites.
Continue to alter the quality and availability of the freshwater migration corridor Freshwater migration corridors for endangered steelhead include water quantities that are sufficient to support adult and juvenile mobility and survival (National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)), including rain-induced periods of elevated river discharge during winter and spring (Shapovalov and Taft 1954, Spina et al. 2005). As described in greater detail below, the continued alteration in the timing, magnitude, frequency and duration of river discharge would continue reducing the quality and availability of the freshwater migration corridor. This reduction is anticipated to cause these persistent adverse effects to the freshwater migration corridor, despite Reclamation’s proposed measures (e.g., types of supplemental water releases from Bradbury Dam) that are intended to minimize the effects.
One way the proposed action is expected to reduce the quality and availability of the freshwater migration corridor involves the timing of elevated water releases from Bradbury Dam. Typically the principal freshwater migration corridor is created and maintained through periodic rainfall events and associated pulses in river discharge during the wet season. Our findings indicate the proposed action will continue the long-standing tradition of periodically shifting the timing of discharge pulses from the wet season to the dry season (e.g., Figure 2-11). The occasional shift in the timing of elevated river discharge to the dry season constitutes a reduction in the quality and availability of the freshwater migration corridor, and therefore an adverse effect.
Further impacts to the quality and availability of the freshwater migration corridor are expected to coincide with dramatic decreases in the magnitude of river discharge as a result of the proposed action. The availability of the migration corridor will be impacted because lower discharge reduces the extent of the wetted channel, particularly within riffles and runs, and therefore migratory space. Additionally, evidence indicates river discharge, particularly of relatively low magnitude, would rapidly wane, resulting in a temporally and spatially limited travel corridor. With regard to quality of the migration corridor, the reduced sediment supply and river discharge would decrease the effectiveness of the habitat to serve as a travel corridor, chiefly through reduced channel bed complexity and decreased magnitude and distribution of water-column depths and velocities, and the frequency and duration that the corridor contacts floodplain areas.
The continued decreases in the frequency and duration of river discharge downstream of Bradbury Dam represent another adverse effect to the quality and availability of the freshwater migration corridor. The magnitude of water releases from Bradbury Dam that is needed to provide a freshwater migration corridor (e.g., river discharge greater than minimum passage flows such as 25 cfs, Bureau of Reclamation 2013a, or 63 cfs, O’Dowd et al. 2014) will be frequently lower, and for a shorter time, than without the proposed Bradbury Dam operations (Figure 2-18, Table 2-4).
77 In reviewing these findings, we want the reader to be mindful of the distinction between water releases for ‘passage’ (i.e., the act of moving from one adjacent mesohabitat to another) versus ‘migration’ (a behavioral-induced seasonal journey to sustain specific life-history function).
Minimum instream flows for passage (e.g., the 25 cfs reported in Bureau of Reclamation 2013a) do not sustain the migratory behavior and ecology of steelhead. Minimum-passage flows only account for the smallest needs of the species to physically navigate through a column of water.
In contrast, because migratory behavior and ecology evolved under the natural flow regime (e.g., Richter et al. 1996, Richter et al. 1997, Lytle and Poff 2004), characteristics of the unimpaired flow regime (e.g., the timing, magnitude, duration, frequency, and rate of change of flows), not a minimum-passage flow, provides the hydrologic cues that cause and maintain migration. For example, O’Dowd et al. (2014) predicted flow ranges, based on hydraulic thresholds, that provide “higher” quality physical and biological features of critical habitat in the Santa Ynez River for various steelhead life-history stages (Figure 2-19), including the freshwater migration corridor; these flows are well in excess of suggested minimum-passage flow (Figure 2-19).
Therefore, our application of the 25 cfs and 63 cfs here is solely to develop additional understanding about how the proposed action may affect designated critical habitat for endangered steelhead, and should not be construed as endorsement for either of these specific minimum-flow values.
Figure 2-18. Number of days for a freshwater migration corridor in the Santa Ynez River downstream of Bradbury Dam is ≥25 cfs (“Passage opportunity”on y-axis) at Solvang, CA, for the period of January through April, 1942-2012, and two conditions: Without current or proposed Bradbury Dam operations, and Proposed operations (source: Bureau of Reclamation 2013a). Water-year type is based on inflow to Cachuma Reservoir:
Critically Dry (<4,550 ac-ft), Dry (4,551-15,366 ac-ft), Below Normal (15,367-33,707 ac-ft), Above Normal (33,708-117,842 ac-ft), and Wet (>117,842 ac-ft). The annual loss or reduction of passage opportunity was greater than 40 percent in water-years categorized “below normal” and “above normal,” occurring in about 40 percent of the years.
78 Table 2-4. Comparison of the number of days for a freshwater migration corridor (i.e., daily mean flow, ≥25 and ≥63 cfs) in the Santa Ynez River at Solvang, CA between December 1 and May 31 for water-years 2006 through 2013 under two conditions: “Without” current or proposed Bradbury Dam operations (i.e., available discharge without current or proposed operations of Bradbury Dam) and “Proposed” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). The proposed action is expected to reduce the number of days for a freshwater migration corridor by 30 to 48 percent and 43 to 73 percent based on the identified minimum passage-flows of 25 and 63 cfs, respectively.
Wtr yr
Days ≥25 cfs Reduction Days ≥63 cfs Reduction
Withoutc Proposedd Days % Withoutc Proposedd Days %
2006a 130 89 41 32 101 53 48 48
2007b 0 0 0 0 0 0 0 0
2008a 124 66 58 47 90 51 39 43
2009b 47 3 44 94 27 1 26 96
2010a 117 61 56 48 91 25 66 73
2011a 165 116 49 30 163 55 108 66
2012b 9 0 9 100 2 0 2 100
2013b 2 0 2 100 0 0 0 0
Total: 594 335 259 44% 475 185 290 61%
a
“Wet” or “Above Normal” water-year type. b“Dry” or “Critically Dry” water-year type. cWithout is predicted daily average flow by adding Cachuma Reservoir inflow (USGS gaging stations 11123500 (Santa Ynez River below Los Laureles Canyon Creek) and 11124500 (Santa Cruz Creek)) to river flow downstream of Cachuma Reservoir (Cachuma Reservoir releases subtracted from USGS 11128500 (Solvang, CA)). d Proposed is measured daily
average flow at USGS gaging station at USGS 11128500 (Solvang, CA) because the proposed operation is expected to result in the same or lower discharge values as the current operation.
Figure 2-19.—Expected range of stream flows for each steelhead life stage’s physical habitat needs in the Santa Ynez River at Solvang, CA in relation to hydraulic thresholds (source: O’Dowd et al. 2014). 79 Although several of the water years in our analysis can be categorized as “dry” or “critically dry,” our findings revealed that certain periods of storm-induced river discharge appeared sufficient to promote a freshwater migration corridor for lengthy periods during such water years, without current and proposed operations of Bradbury Dam (Figure 2-20). In contrast, under the proposed action, similar migration opportunities are not observed.
Another adverse effect of the proposed action on the freshwater migration corridor involves hydrologic discontinuity. Analyses indicate hydrologic synchrony between freshwater migration corridors in the main-stem river and tributaries would be disrupted. This is especially true during spring, one of many seasons when maintaining a continuous, unobstructed freshwater migration corridor is crucial. For instance, the duration of the migration corridor in Salsipuedes Creek is longer lived than in the lower main stem, which rapidly declines to zero under the proposed action (Figure 2-21). In addition to these findings, other investigators similarly report extensive hydrologic discontinuity in the main-stem river during spring (O’Dowd et al. 2014) (Figure 2- 22).
Figure 2-20.—Daily mean discharge in the Santa Ynez River at Solvang, CA, from February 1, 2009 through April 30, 2009 (considered a dry year), representing a selected storm-induced flow sequence relative to minimum-passage flows of 25 cfs and 63 cfs under three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without current and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). Because the current and proposed operations are essentially the same, these lines overlap and appear as a single line. 80 Figure 2-21. —Daily mean discharge during January through May for water years 2008-2010 in the Santa Ynez River near Solvang (RM 39) and Lompoc (RM 10), and Salsipuedes Creek, entering the Santa Ynez River at RM 18. Santa Ynez River discharge near Solvang includes predicted flow “without current Bradbury Dam operations” and measured flow “with current Bradbury Dam operations.” l():)OO_O
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__ ......... "mm"nm m m<.""m m m."",m,..",, m' ",,,.,ft,,,, m' on" m,,<" n"'_"' .... '''..,.., .. --- Santa yo". Ri"", at SulvaoS_RM 3'>1 (wilhout cu,,"'" 8radbury Dam uperal;.,,,.) ----- Sanla YO ... Ri"", al Sulv"oS_RM 3'>1 (with cu"e,,1 Bradbur y Da", upe,.ati"".) - - S~n.~ Yne7 Hi"",~ , 1.<>mp<:>c_KM 10 (with c""ent Hr~dbury Oam ope''''''"') --- Sal.ipuede$ Cre,,~
81 Figure 2-22.—Dates that minimum connectivity is observed at Lower Salsipuedes Creek (QMinConnect = 1.0 cfs) against dates for the main stem Santa Ynez River at ‘H’ Street (2.7 cfs) across 13 water years. The bold diagonal line is 1:1 relationship between the date of minimum connectivity in the main stem river and Lower Salsipuedes Creek. Values above the 1:1 line indicate an earlier date of reaching the minimum streamflowconnectivity value on the main stem versus the tributary, increasing the likelihood of hydrologic discontinuity and a related migration obstruction in the main stem river. On average, the minimum-connectivity value was observed 50 days sooner on the main stem than on the tributary (O’Dowd et al. 2014).
While the proposed action includes conservation water releases to reduce adverse effects on the freshwater migration corridor (i.e., Passage Flow Supplementation water releases), our review indicates the proposed operations (including the conservation water releases) would do little, if anything meaningful, to offset the continued effects of operations. Our review of the decision criteria for the conservation water releases, alone, indicate a low likelihood the releases would be implemented (see Table 2-5 for a review of the criteria deficiencies). Overall, the proposed action will have the functional effect of maintaining inadequate freshwater migration corridors unless tributary inflow is sufficient to create and sustain migration opportunities for adult steelhead in the river main stem downstream of Bradbury Dam.
While not as dramatic, we document a similar temporal decline in the main stem migration corridor in the vicinity of Solvang, but flow data for a neighboring tributary are not available.
Although the specific cause for the rapid decline and eventual elimination of the migration corridor near Lompoc is not explicit, the available information suggests the reduced water releases from Bradbury Dam, in combination with groundwater withdrawals in the lower main stem, as likely causes (Bureau of Reclamation 2013a, O’Dowd et al. 2014). 82 Table 2-5. Summary of the deficiencies and implications due to Reclamation’s proposed decision criteria for triggering passage-supplementation water releases from Bradbury Dam. The intended purpose of the releases is to increase migration opportunities in the main stem Santa Ynez River for adult steelhead.
Decision criteria Deficiency Implications for critical habitat Cachuma Reservoir must fill
and spill ≥20,000 ac-ft of
water to establish the Fish
Passage Account.
Criterion reduces the likelihood that the Fish Passage Account would frequently be established. Spills are dependent on available storage, which is affected by reservoir operations including water withdrawals to support domestic water users within and outside the watershed. As many as 8 consecutive years between spills has occurred since Cachuma Reservoir was established.
Reduces the likelihood that water release
from Bradbury Dam would ensure a
properly functioning migration corridor.
Results in a highly altered freshwater
migration areas.
The Fish Passage Account
limited to 3,200 ac-ft.
The amount of water allocated for fish-passage water releases is not sufficient. The Fish Passage Account is exhausted after supplementing only two discharge pulses. The likelihood that discharge pulses would be supplemented is low.
Reduces the likelihood that water release
from Bradbury Dam would ensure a
properly functioning migration corridor.
Results in an extremely altered freshwater
migration areas. .
The storm to be
supplemented with passageflow water releases is within the migration season of
January to May.
Criterion does not fully account for the entirety of the steelheadmigration window (e.g., Fukushima and Lesh 1998). Affects timing of water releases.
Artificially truncates the quality and
availability of the freshwater migration
areas.
Discharge in the main-stem
river measured at the
Solvang gage must be ≥ 25
cfs.
Because operation of Bradbury Dam alters the pattern and diminishes the magnitude of river discharge, the frequency and duration this criterion would be met is artificially reduced.
Perpetuates existing effects of Bradbury
Dam operations on the quality and
availability of the freshwater migration
areas.
Accumulation of daily
average discharge since
December 1 at the
Salsipuedes Creek USGS
gage is ≥ 1,000 AF.
Criterion reduces the likelihood and timing of water releases from Bradbury Dam to create meaningful migration
opportunities. Ignores the role of discharge pulses in cuing and facilitating migration of steelhead, including establishing groundwater and surface water conditions (e.g., connectivity) to make subsequent discharge pulses more effective for migration.
Criterion artificially reduces the quality and
frequency (availability) of the freshwater
migration areas.
The sandbar at the mouth of
the estuary must be
breached.
Criterion perpetuates existing effects of Bradbury Dam
operations on the quality and availability of the freshwater migration corridor. The operation of Bradbury Dam alters the frequency and duration of breaching, hence the frequency and duration this criterion would be met is artificially reduced.
Reduces likelihood of water releases from Bradbury Dam to create meaningful migration opportunities.
Reduced quality and availability of the
freshwater migration areas.
The first storm in January
will not be supplemented.
Contradicts Reclamation’s decision criterion involving the seasonal migration window for steelhead. Ignores the natural role of discharge pulses in cuing and facilitating migration of steelhead, including establishing groundwater and surface water conditions (e.g., connectivity) to make subsequent discharge pulses more effective for migration. Reduces likelihood of water releases from Bradbury Dam to create meaningful migration opportunities.
Reduced quality and availability of the
freshwater migration areas.
Supplement water releases
unless: (a) flows at Solvang
reach 25 cfs within the 7
days following a prior
migration flow release, (b)
the decision group
determines greater
biological benefit not to
supplement, or (c) there is
no water remaining in the
Fish Passage Account.
Criterion perpetuates existing effects of Bradbury Dam
operations on the quality and availability of the freshwater migration corridor. Increases potential that river discharge maintained at relatively low levels. Ignores the natural role of discharge pulses, including successive pulses, in cuing and facilitating migration of steelhead. Assumes passage
requirements will meet migration requirements.
The quality and availability of the
freshwater migration areas would remain
artificially truncated.
83 The continued geomorphic adverse effects of the proposed action to natural habitat-forming processes are projected to translate into adverse effects on the freshwater migration corridor (Table 2-6), and Reclamation does not propose to remediate these effects. For instance, the proposed action would continue capturing most flood flows in Cachuma Reservoir that are important for creating and maintaining important habitats for anadromous salmonids (e.g., Beechie and Bolton 1999, Beechie et al. 2010). In addition, the proposed action would continue to block the natural input of sediment and organic material from upstream of Bradbury Dam throughout the downstream reach. Disrupting flood flows and inputs of sediment (gravel, cobble, boulder) and organic material (e.g., large woody debris) reduces or precludes development and maintenance of physical or biological features of functional freshwater migration corridors, such as riffle-pool sequences and in-channel cover elements that provide hydraulic complexity that promotes mobility and provides sheltering or resting areas for migrating steelhead. The proposed action’s adverse effects on the freshwater migration corridor are anticipated to persist unabated into the future, and we therefore project that the proposed action will continue to reduce the value of designated critical habitat for the conservation of the species.
The artificially reduced magnitude and frequency of floods in the river as a result of the proposed action increases opportunities for the establishment of beaver dams. These dams are a recognized problem in the action area because they represent obstructions in the freshwater migration corridor for endangered steelhead (Bureau of Reclamation 2013a, 2013d, 2015f) at the range of highly impaired migration flows that are proposed. Bradbury Dam will continue to capture most high flows that could scour the beaver dams from the channel. Although Reclamation proposes a plan that is intended to control beaver activity in the action area, there are several reasons why we expect the plan will not materially improve the quality of the freshwater migration corridor. For instance, the proposed control activities are admittedly experimental and are generally intended to only explore the potential for removing or modifying the dams and controlling beaver. The plan lacks a proposed schedule and assurance that the proposed activities would be undertaken (we note the term “may” is applied to most of the proposed activities). The plan is spatially limited in scope; only a relatively short stretch of the main-stem river is accessible to Reclamation; therefore, a number of beaver dams would remain in place elsewhere, despite the potential for Reclamation to undertake dam-modification or removal efforts in accessible reaches. For example, more than 80 beaver dams were observed in the main-stem river during a survey conducted in January 2011, none of which were in the short reach (about 0.75 miles) controlled by Reclamation (Bureau of Reclamation 2013e). Effecting proposed desiccation of certain downstream reaches in select years to eradicate beaver would only produce temporary consequences (not to mention the adverse effects on any steelhead holding in the dewatered area). Perhaps most importantly, Reclamation’s plan targets a symptom of river regulation rather than the cause (i.e., dam and associated operations). 84 Table 2-6. Anticipated impacts of the proposed action (in main-stem river downstream of Bradbury Dam), expected effects on the freshwater migration corridor for endangered steelhead, and whether the proposed action includes a program to monitor and remedy the expected impacts. Source for anticipated impacts:
Ligon et al. (1995), Kondolf (1997), Trush et al. (2000), Willis and Griggs (2003), Slagel and Griggs (2008), O’Dowd et al. (2014), and Harrison et al. (in revision).
Anticipated impacts Expected effects on freshwater migration corridor
Proposed
monitoring and
remediation?
Accumulation of sediment in pools (inadequate
frequency and magnitude of water releases to
scour/maintain pools).
Reduced quality and availability due to effects of
accumulation of surficial sand and smaller
particles, reduced number and quality of resting
or sheltering areas.
No
Vegetation encroachment of the low-flow
channel (inadequate frequency and magnitude of
water releases to scour seedlings).
Reduced quality and availability, e.g., decrease in
corridor width, preclude formation and
maintenance of broad riffles.
No
Trapping coarse sediment and organic debris
behind the dam, decrease delivery downstream,
and cause channel-bed erosion.
Reduced quality, e.g., simplification of the
alluvial river channel, reducing hydraulic
complexity (water depths and velocities) that
promote mobility.
No
Limited or no natural lateral migration of the
active channel, or re-working of the channel and
floodplain (inadequate frequency and magnitude
of water releases to periodically re-shape
channel features).
Reduced quality, e.g., constrained development
of complex channel margin and floodplain
habitat, encroachment of riparian vegetation.
No
Limited or no natural formation of off-channel
chutes, or bar development (inadequate
frequency and magnitude of water releases to
create and maintain channel/habitat features).
Reduced quality and availability due to
simplification of the alluvial river channel,
decrease in number and quality of resting or
sheltering areas.
No
Prevent natural increases in the number and size
(length, depth) of pools, broad riffles
(inadequate frequency and magnitude of water
releases to create and maintain channel/habitat
features).
Reduced quality and availability, e.g., decrease in
number and quality of resting or sheltering areas
and feeding areas.
No
85 Continue to reduce the availability and quality of freshwater spawning sites Freshwater spawning sites are those “…with water quantity and quality conditions and substrate supporting spawning, incubation and larval development” (National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)). These areas are essential for adult steelhead to volitionally complete their life cycle and spawn in winter or spring.
The Santa Ynez River downstream of the current location of Bradbury Dam was documented to provide spawning habitat (Shapovalov 1944) and a migration corridor to extensive areas of suitable spawning habitat farther upstream in the main stem and tributaries, as well as tributaries downstream of the current dam location. However, the physical effects from the proposed action will continue reducing the availability of suitable freshwater spawning sites and the quality of available freshwater spawning sites in the main-stem river downstream of Bradbury Dam.
The expected impacts of the proposed action on the pattern and magnitude of river discharge are not anticipated to be effective for developing and preserving riverine habitats (Poff et al. 1997) primarily because the action does not include the sorts of deliberate water releases that are necessary for this purpose (Harrison et al., in revision). Regulated rivers can become incised and dominated with large substrate particle types (e.g., through the winnowing of small cobbles and gravels), vegetation can encroach into the channel, and extensive accumulations of sand and smaller particles can be observed, thereby limiting the availability and quality of freshwater spawning areas (Table 2-7).
The available information indicates operation of the dam has encouraged extensive accumulations of surficial sand and smaller particles in the Santa Ynez River downstream of the dam, and a reduction in the quality of freshwater spawning areas. Recent observations of the 10- mile reach immediately downstream of Bradbury Dam characterize this habitat as having limited suitable spawning sites with approximately 38 percent of the habitat comprised of beaver-dam pools layered with fine sediment (Bureau of Reclamation 2013a), a consequence of artificially reduced river discharge events that otherwise would breach beaver dams and flush fine sediments. By contrast, this area was described as providing “excellent” spawning sites (Shapovalov 1946, as cited in Titus, et al. 2010) prior to the construction and operation of Bradbury Dam.
In addition, we examined specific water years when steelhead spawning was observed or likely in the Santa Ynez River (i.e., 2006, 2008, 2010 and 2011). The findings indicate an artificially quickened rate that surface flows decline, and a reduction in median and minimum discharges during the spawning season (Figures 2-23, 2-24 and 2-25) resulting from the proposed action.
These findings indicate the habitats and related conditions needed for successful spawning, incubation, and emergence would not be sustained in the Santa Ynez River downstream of Bradbury Dam.
Overall, our review indicates that the proposed action will continue to reduce the quality of spawning sites in the Santa Ynez River downstream of Bradbury Dam (i.e., undesirable water depth and velocity, and spawning substrate), as well as the availability of spawning areas in tributaries downstream of the dam by altering the freshwater migration corridor as discussed above (see Continue to alter the quality and availability of the freshwater migration corridor).
This is of concern for at least the following reasons:
86 1) The physical effects of Bradbury Dam would continue to reduce the quality and availability of freshwater spawning areas in the river main stem below the dam, and the availability of freshwater spawning areas in tributaries below Bradbury Dam appears limited (e.g., the 10 miles of the Santa Ynez River downstream of Bradbury Dam that provided spawning sites of “excellent” quality prior to construction and operation of the dam (Shapovalov 1946, as cited in Titus, et al. 2010), has been reduced in quantity and quality (Bureau of Reclamation 2013a); and,
2) The proposed action contains no meaningful provision to monitor and remedy the effects of the proposed action on the availability and quality of freshwater spawning sites downstream of Bradbury Dam.
Table 2-7. Anticipated impacts of the proposed action (in main-stem river downstream of Bradbury Dam), expected effects on the availability and quality of freshwater spawning sites for endangered steelhead, and whether the proposed action includes a program to monitor and remedy the expected impacts. Source for anticipated impacts: Cordone and Kelley (1961), Ligon et al. (1995), Kondolf (1997), Trush et al. (2000), Willis and Griggs (2003), Slagel and Griggs (2008), O’Dowd et al. (2014) , and Harrison et al. (in revision).
Anticipated impacts Expected effects on availability and quality of freshwater spawning areas
Proposed
monitoring and
remediation?
Accumulation of sediment in pools, including poolriffle transitions (inadequate frequency and magnitude of water releases to scour/maintain pools).
Reduced quality and availability due to effects of
accumulations of surficial sand and smaller particles.
No
Vegetation encroachment of the low-flow channel
(inadequate frequency and magnitude of water
releases to scour seedlings).
Reduced quality and availability, e.g., decrease in
corridor width and related spawning space.
No
Trapping coarse sediment and organic debris behind
the dam, decrease delivery downstream, and cause
channel-bed erosion.
Reduced quality and availability due to increased
sediment particle size and reduction in sheltering or
resting areas for adults.
No
Limited or no natural lateral migration of the active
channel, or re-working of the channel and floodplain
(inadequate frequency and magnitude of water
releases to periodically re-shape channel features).
Reduced quality and availability, e.g., constrained
development of complex channel margin and floodplain
habitat, decrease in the number and size of resting or
sheltering areas, and reduced development and
maintenance of pool-riffle sequences.
No
Limited or no natural formation of off-channel chutes,
or bar development (inadequate frequency and
magnitude of water releases to create and maintain
channel/habitat features).
Reduced quality and availability due to simplification
of the alluvial river channel, decrease in resting or
sheltering areas, and reduced pool-riffle sequences.
No
Prevent natural increases in the number and size
(length, depth) of pools, broad riffles (inadequate
frequency and magnitude of water releases to create
and maintain channel/habitat features).
Reduced quality and availability, e.g., decrease in
number and quality of resting or sheltering areas, and
reduced pool-riffle sequences.
No
87 Figure 2-23.—Daily mean discharge in the Santa Ynez River at Solvang, CA occurring from February 20 to May 31 in water years 2006, 2008 and 2010 representing example discharge pulses under two conditions:
“Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). Only two flow conditions are presented in each panel to simplify the presentation.
88 Figure 2-24.—Comparison of median and minimum daily mean discharge in the Santa Ynez River at Solvang, CA occurring January through May in water years 2006 and 2008 for three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria). 89 Figure 2-25.—Comparison of median and minimum daily mean discharge in the Santa Ynez River at Solvang, CA occurring January through May in water years 2010 and 2011 for three conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., the projected discharge resulting from Reclamation’s proposed operating criteria).
Continued reduction in the quality and availability of freshwater rearing sites Freshwater rearing sites possess “water quantity and floodplain connectivity to form and maintain physical habitat conditions and support juvenile growth and mobility; water quality and forage supporting juvenile development; and natural cover such as shade…” (National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)).
The preponderance of the available information indicates that while the proposed action is expected to have some beneficial effects on freshwater rearing areas, the type and severity of the 90 continued adverse effects greatly outweigh the anticipated beneficial effects. Our analysis of the effects begins with a discussion of the anticipated beneficial effects of the action, and concludes with a description of the expected adverse effects.
The proposed continued operation of the Hilton Creek Watering System is intended by Reclamation as a beneficial aspect of the action, though it constitutes a very small percentage of potential rearing habitat below Bradbury Dam (<1%) (see Figure 2-6). Designated critical habitat in Hilton Creek can benefit from an artificial watering system constructed and operated by Reclamation; continued operation of the watering system is included in the proposed action.
As part of the mitigation for the Bradbury Dam Seismic Retrofit Project completed in 2006, the watering system is intended to provide perennial flow in the lower 0.5 miles of Hilton Creek, which contributes to year-round freshwater rearing areas. Although the proposed action is intended to provide continuous streamflow in this reach of Hilton Creek, consistent with current operations, streamflow has ceased on several occasions as a result of electrical or mechanical outages in the watering system. The interruption in discharge and effects to critical habitat has been temporary and generally brief (hours to days), and Reclamation has implemented a backup watering system to minimize or prevent future flow interruptions in Hilton Creek. Because the effects to critical habitat resulting from the watering system are principally positive (providing year-round rearing habitat), and potential negative effects resulting from streamflow interruption are temporary and expected to be avoided or reduced in the future, we do not expect this aspect of the proposed action to reduce the functional value of critical habitat in Hilton Creek.
Another anticipated benefit of the proposed action, similar to current operations, involves the increased availability of freshwater rearing areas during the dry season in the vicinity of Bradbury Dam. The proposed water releases are expected to maintain river discharge downstream of the dam throughout the dry season for a distance of 3 miles, or more, in about 86 percent of years (Bureau of Reclamation 2013a). The water releases during the dry season are generally expected to increase the availability of rearing space, and therefore critical habitat for endangered steelhead. We emphasize that the principal benefit lies with the increased availability of living space, but as discussed later in this section, the quality of this freshwater rearing area is of concern.
Having described the expected beneficial aspects of the proposed action for freshwater rearing areas downstream of Bradbury Dam, we now transition to the anticipated adverse effects of the action. In particular, we emphasize how the proposed action would continue worsening or preventing the physicochemical capacity of freshwater rearing areas downstream of Bradbury Dam from sustaining life-history pathways for the species. In doing so, we wish the reader to be keenly aware that freshwater rearing areas for endangered steelhead include instream and estuarine areas, and rearing areas must be available year round to sustain the life history and habitat requirements of this species.
The effect of the proposed operations on hydrologic synchrony between river main stem and joining tributaries during late winter and spring constitutes an adverse effect on freshwater rearing areas. For example, the duration of the freshwater rearing area in Salsipuedes Creek is longer lived than in the lower main stem, which rapidly declines to zero under the proposed action (Figure 2-21). This finding is consistent with the findings of O’Dowd et al. (2014), whom report extensive hydrologic discontinuity in the main stem during spring (Figure 2-22). 91 To further illustrate the discontinuity between main stem and tributary rearing sites we examined gaging records representing an above-normal water year to compare relative discharge contributions (i.e., without and with proposed Bradbury Dam operations) in the Santa Ynez River at Solvang with a proximate tributary (Alisal Creek) (Figure 2-26). The results of this comparison indicate the proposed action would result in hydrologic asynchrony between main stem and tributary discharges, and between main stem and tributary rearing sites. We emphasize that while the specific cause for the rapid decline and eventual elimination of main stem freshwater rearing areas, for example near Lompoc, is not explicit, the available information indicate the combined influence of the proposed action and groundwater withdrawals in the lower main stem as likely causes (e.g., Robinson et al. 2007, Bureau of Reclamation 2013a).
As another measure of the effects of the proposed action on the availability and quality of freshwater rearing sites during winter and spring, we considered the specific changes in width, depth, and discharge. An available discharge-habitat relationship for the Santa Ynez River (SYRTAC 1999) indicates that when discharge decreases from 50 cfs to 10 cfs in the vicinity of Solvang, the width and maximum depth of riffles decline about 25 and 33 percent, respectively.
As illustrated in Figures 2-24, 2-25 and 2-27, the proposed action appreciably reduces the magnitude and duration of discharge in the Santa Ynez River during winter and spring for a range of water-year types (e.g., 2008 above normal, 2009 dry, 2010 above normal, and 2011 wet) suggesting a profound reduction in the quality and availability of rearing areas in a given year.
Figure 2-26.—Relation between daily mean discharge contribution to the Santa Ynez River at Solvang, CA under two conditions “Without Bradbury Dam Operations” (i.e., Cachuma Reservoir inflow minus predicted flow loss between Bradbury Dam and Solvang) and “Proposed Operations” (i.e., proposed Bradbury Dam releases reaching Solvang), and mean daily discharge measured in Alisal Creek. 92 Figure 2-27.—Daily mean discharge in Santa Ynez River, Solvang, from January 1 through May 31 in water years 2008, 2009, 2010 and 2011 representing a range of water year types (dry to wet) under three conditions:
“Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current Operation” (i.e., discharge due to current operation), and “Proposed Operation” (i.e., projected discharge resulting from Reclamation’s proposed operating criteria). 10000.0
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93 With regard to the availability of freshwater rearing sites during the dry season, the proposed action will continue confining the main stem rearing sites to within a reach extending three to ten miles downstream of Bradbury Dam. Prior to construction of Bradbury Dam (but following construction and operation of Gibraltar Dam and existence of groundwater pumping that was already affecting river flow), summer rearing habitat in the Santa Ynez River main stem downstream of the dam was limited to the estuary and several miles of river in the vicinity of Solvang (located about 10 miles downstream from Bradbury Dam) that was sustained by groundwater (Shapovalov 1944), and isolated deep pools between Solvang and Bradbury Dam (Bureau of Reclamation 2013a). The extent of potential dry-season rearing habitat under the proposed action is dependent upon the particular water-release scenario implemented in a given year. The proposed action is intended to maintain surface flow throughout the dry season for a distance of about 10 miles downstream of the dam in about 24 percent of years (i.e., Alisal Bridge near Solvang), 3 to 5 miles downstream of the dam in about 62 percent of years, and less than 0.75 miles downstream of the dam in about 14 percent of years (Table 2-8). Although the extent of surface flow beyond the Highway 154 Bridge (3 miles downstream of Bradbury Dam) is not defined for releases that maintain 2.5 and 5 cfs at this location, information (e.g., Bureau of Reclamation 2013a) indicates surface flows cease between 3 to 5 miles downstream of Bradbury Dam under these conditions.
To gain a better understanding of the potential extent of dry-season rearing habitat in this segment of the Santa Ynez River, we examined discharge records prior to the construction of Bradbury Dam (Figure 2-27) (but following construction and operation of Gibraltar Dam). This analysis indicates the river regularly experienced intermittency immediately downstream of the dam, yet subsequently resurfaced and flowed throughout the summer and fall in the area 10 miles downstream. This is true for all water years except critically dry years (<10% occurrence probability) (e.g., surface flow ceased at the USGS gage near Solvang in August and September of 1948, a critically dry year that followed a dry year). Extensive pumping of alluvial groundwater (Environmental Baseline and Cumulative Effects), along with decreased river discharge and managing alluvial groundwater at depleted storage levels under the proposed action, has reduced the extent and shifted the location and source (i.e., groundwater to surfacewater discharge) of summer rearing sites. Recent information indicates over-summer rearing habitat appears confined to the 3 to 5-mile reach immediately downstream of Bradbury Dam in about 62 percent of years, with extended availability 10 miles downstream of the dam in about 24 percent of years (i.e., to Alisal Bridge near Solvang), and is dependent on Bradbury Dam water releases to maintain surface flow to these rearing sites. Water releases during the remaining 14 percent of years, under the proposed action, would provide surface flow only for about 0.75 miles or less downstream of Bradbury Dam (Bureau of Reclamation 2015i, Stetson 2015). Furthermore, the proposed action, in comparison with current operations, reduces the annual frequency of water releases necessary to maintain flow from the dam to the Highway 154 Bridge (from 98% to 86% of years) (Bureau of Reclamation 2015i) and to the Alisal Bridge (from 39% to 24% of years) (Bureau of Reclamation 2013a). 94 Table 2-8. Anticipated discharge in the Santa Ynez River at the Highway 154 Bridge and Alisal Bridge representing the lowest period of river discharge (August and September) under the proposed operations of Bradbury Dam (source: Bureau of Reclamation 2013a). The Highway 154 Bridge and Alisal Bridge are about 3 miles and 10 miles downstream of Bradbury Dam, respectively.
Bradbury Dam/Cachuma
Reservoir Storage
Santa Ynez River Discharge (cfs) Frequency
Hwy 154 Bridge Alisal Bridge (% of years)
Spill ≥20,000 ac-ft 10 cfs 3 cfs 24%
Storage >120,000 ac-ft 5 cfs 0 cfs
62%
Storage <120,000 ac-ft 2.5 cfs 0 cfs
Project Water <30,000 ac-ft1 or
when a critically dry year2 follows
a dry year3 or critically dry year
0 cfs 0 cfs 14%
1 Project Water does not include (a) water stored for minimum pool volume of 12,000 ac-ft, (b) water stored for groundwater recharge (i.e., WR 89-18 releases), and (c) water stored as “carry over” (i.e., Project Water allocated to Member Units in preceding year that was not used and remained in storage) (Reclamation 2015b); therefore, total reservoir storage may be much greater than 30,000 ac-ft. 2 Critically dry year equates to ≤4,550 ac-ft of inflow to Cachuma Reservoir during a water year. 3 Dry year equates to 4,551 to 15,366 ac-ft of inflow to Cachuma Reservoir during the water year.
Figure 2-27. —Daily mean discharge for water years 1933-1938 in the Santa Ynez River near Santa Ynez (USGS 11126000) and Solvang (USGS 11128500) located about 0.5 and 10 mile downstream of Bradbury Dam, respectively. These data represent river flow prior to the construction of Bradbury Dam for a range of water-year types (i.e., dry, below normal, normal, and wet). 95 Reports of others further corroborate that the proposed action would continue limiting the physicochemical capacity of freshwater rearing areas. For instance, operations of Bradbury Dam can create harmful or even lethal instream conditions by not maintaining surface flows downstream of the dam (Robinson et al. 2007). The proposed action lacks the sort of water releases that are essential to create and maintain important rearing sites for juvenile steelhead in the lower main-stem river (e.g., Harrison et al., in revision). Therefore, the proposed action is expected to continue to limit the quality and availability of freshwater rearing sites.
The water releases under the proposed action intended to support freshwater rearing sites (i.e., rearing-flow supplementation) do not appear to contain sufficient provisions to moderate effects of air temperature on the availability of suitable freshwater rearing sites during summer.
Reclamation (2013a) concludes that the effectiveness of water releases from Bradbury Dam to moderate summer water temperature appears limited to the 5-mile reach immediately below Bradbury Dam. In particular, they suggest a minimum water release threshold between 9 and 13 cfs, with improved water-quality conditions demonstrated at a water-release rate of 16 cfs.
However, the suggested minimum releases (9 to 13 cfs) are only expected to occur in about 24 percent of years under the proposed action, with no provision for additional releases to moderate summer water temperature. Proposed operations during the remaining years (76% of years) are expected to result in reduced quantity and quality of summer rearing sites below Bradbury Dam with increasingly stressful conditions at lower water-release rates.
The water-rights releases, which are proposed for continuation as part of the proposed action, can ameliorate harmful to lethal conditions at summer rearing sites (Boughton et al. 2015).
However, the administrative record indicates these water releases have not and would not occur until after rearing sites have been dewatered or deteriorated to potentially lethal levels (Figures 2-28 and 2-29)22. In addition, Reclamation proposes a change to the downstream targets for the summer water releases during critically dry years. The purpose of the change is to eradicate beaver and non-native aquatic nuisance species (Bureau of Reclamation 2015i). During critical drought years, surface water is not expected in the “Highway 154 reach” during critically dry years that follow another dry or critically dry year.
22 Reclamation conducts water-rights releases from Bradbury Dam at the request of the Santa Ynez Water Conservation District for the purpose of groundwater recharge and associated diversion/groundwater pumping of river flow. However, Reclamation has discretion to manage water-rights releases (i.e., timing or rate) for the purpose of maintaining dry-season rearing habitat for steelhead. 96 Figure 2-28. —Daily mean discharge in the Santa Ynez River at Bradbury Dam and Solvang, about 10 miles downstream of Bradbury Dam, in 2013. The discharge pulse in mid-July reflects water-rights releases from Bradbury Dam. In this graph, the releases happen significantly after rearing habitat in the main stem has been diminished or eliminated.
Introductions of non-native fish to the river downstream of Bradbury Dam are expected to reduce the quality and availability of freshwater rearing areas. The source of the non-native fish is Cachuma Reservoir and the mechanism of introduction involves uncontrolled spills of water (Bureau of Reclamation 2013a, Bureau of Reclamation 2015i) and potentially transit through the dam outlet. A reduction in the quality and availability of the freshwater rearing areas is expected for at least a few reasons.
First, when in a river or stream non-native fish can outcompete and consume native species including steelhead (Cucherousset and Olden 2011). For this reason, introduction of non-native fish is expected to limit the function and value of freshwater rearing areas in specific river reaches that contain these fish (i.e., non-native fish are distributed throughout and dominate the 10-mile reach below the dam, the principal available rearing habitat for steelhead).
Second, evidence indicates non-native fish are a problem for juvenile steelhead in the river; largemouth bass (Micropterus salmoides) have become the dominant fish species in the river (Cachuma Operation and Maintenance Board 2013a) and feed on juvenile steelhead (Cardno 2015).
97 Figure 2-29.—Comparison of habitat conditions in the Santa Ynez River approximately 5 miles downstream of Bradbury Dam under various water releases from the dam: May 14, 2013 (7.6 cfs), July 2, 2013 (9.0 cfs), and July 23, 2013 (151.5 cfs).
May 14, 2013
July 2, 2013
July 23, 2013
98 Finally, the proposed action does not have a meaningful program that would effectively preclude non-native fish from entering the main-stem river downstream of the dam. While Reclamation proposes a plan to address the problem of non-native aquatic nuisance species in the river (Bureau of Reclamation 2015i), the plan does not target the source of the non-native species (i.e., the reservoir) and generally lacks assurances that non-native species removal would be undertaken. As a result, the problem of non-native species diminishing the function and value of the freshwater rearing site is expected to persist unabated into the future.
The interrelated action of water deliveries from the State Water Project (out-of-basin water) would be released into the Santa Ynez River, potentially affecting the quality of the main-stem river as an olfactory imprinting area for juvenile steelhead. The out-of-basin water could be released into the Santa Ynez River downstream of Bradbury Dam any time during December through June (principal smolt imprinting period) if flow in the river does not extend continuously to the Pacific Ocean. In addition, out-of-basin water would be released into the river at a rate of no more than fifty percent of the total water being released from the dam. Because juvenile steelhead (pre-smolt and smolt) have been observed migrating downstream from tributaries to the main-stem Santa Ynez River during such conditions and are likely undergoing olfactory imprinting, the introduction of out-of-basin water could affect the ability of the habitat to support this critical homing process. However, through implementing the aforementioned measures, no releases of out-of-basin water to the river have occurred from January through May since 2001, and releases in December and June occurred under conditions that smolts are less likely to be imprinting (i.e., smolts not emigrating due to river discontinuity) (Bureau of Reclamation 2013a). Therefore, the likelihood of disrupting the ability of the habitat to further natural smolt imprinting owing to this interrelated action appears remote.
The continued geomorphic effects resulting from the proposed action are expected to diminish the functional value of freshwater rearing areas (see Table 2-9 for a description of the anticipated impacts and effects). In addition, the proposed action blocks natural input of sediment and organic material from upstream of Bradbury Dam to the downstream reach and related routing throughout. Disrupting flood flows and inputs of sediment (gravel, cobble, boulder) and organic material (e.g., large woody debris) reduces or precludes development and maintenance of physical or biological features of functional freshwater rearing sites. Such features include rifflepool sequences, backwater habitats, shoal areas and cover elements providing diverse and complex areas for feeding and sheltering. The proposed action’s adverse effects on rearing sites are anticipated to persist into the future, and we therefore project that the proposed action will continue to reduce the value of designated critical habitat for the conservation of the Southern California steelhead DPS.
99 Table 2-9. Anticipated impacts of the proposed action (in main-stem river downstream of Bradbury Dam), expected effects on the availability and quality of freshwater rearing areas for endangered steelhead, and whether the proposed action includes a program to monitor and remedy the expected impacts. Source for anticipated impacts: Cordone and Kelley (1961), Ligon et al. (1995), Kondolf (1997), Trush et al. (2000), Willis and Griggs (2003), Slagel and Griggs (2008), and Harrison et al. (in revision).
Anticipated impacts Expected effects on availability and quality of freshwater rearing areas
Proposed
monitoring and
remediation?
Accumulation of sediment in pools, including at poolriffle transitions (inadequate frequency and magnitude of water releases to scour/maintain pools).
Reduced quality and availability due to effects of
accumulations of surficial sand and smaller particles.
No
Vegetation encroachment of the low-flow channel
(inadequate frequency and magnitude of water releases
to scour seedlings).
Reduced quality and availability, e.g., decrease in
corridor width and related living space.
No
Trapping coarse sediment and organic debris behind
the dam, decrease delivery downstream, and cause
channel-bed erosion.
Reduced quality and availability due to increased
sediment particle size and reduction in sheltering or
resting areas.
No
Limited or no natural lateral migration of the active
channel, or re-working of the channel and floodplain
(inadequate frequency and magnitude of water releases
to periodically re-shape channel features).
Reduced quality and availability, e.g., constrained
development of complex channel margin and floodplain
habitat and reduced development and maintenance of
pool-riffle sequences, decrease in the number and size
of resting or sheltering areas and feeding areas.
No
Limited or no natural formation of off-channel chutes,
or bar development (inadequate frequency and
magnitude of water releases to create and maintain
channel/habitat features).
Reduced quality and availability due to simplification of the alluvial river channel, decrease in resting or
sheltering areas and pool-riffle sequences.
No
Prevent natural increases in the number and size
(length, depth) of pools (inadequate frequency and
magnitude of water releases to create and maintain
channel/habitat features).
Reduced quality and availability, e.g., decrease in
number and quality of sheltering and feeding areas, and reduced pool-riffle sequences.
No
2.4.1.2 Effects on Critical Habitat due to Maintenance Activities for Bradbury Dam Several of the maintenance activities proposed for Bradbury Dam and related facilities (Table 1- 3) are not expected to affect designated critical habitat. We are referring specifically to the activities that are physically outside of the river channel and riparian corridor and incorporate measures to avoid or minimize potential adverse effects to steelhead habitats. These activities include maintenance of fences and access roads, removal of debris from the dam spillway, control of rodents, and control of vegetation.
Nevertheless, certain maintenance activities would temporarily reduce the amount and extent of designated critical habitat available for endangered steelhead in Hilton Creek and the Santa Ynez River. The maintenance activities that we expect would affect designated critical habitat are (1) testing and maintaining the Hilton Creek watering system, (2) repairing the Bradbury Dam stilling basin, and (3) maintenance of USGS gaging stations.
Activities related to testing and maintaining the Hilton Creek Watering System are expected to 100
cause periodic fluctuations (increases, decreases, or discontinuances) in water releases to Hilton Creek when background flows are low or not present (Bureau of Reclamation 2015j). Annual testing of Hilton Creek water system outlet valves may temporarily (<4 minutes) halt water releases at the corresponding site (upper release point or lower release point) causing a brief reduction of streamflow in Hilton Creek. Testing and maintenance of the Hilton Creek water system pumps could cause water releases to Hilton Creek to temporarily decrease, or cease altogether (Bureau of Reclamation 2015j). Temporary reductions and eliminations of water releases would briefly reduce the function of freshwater migration areas, freshwater spawning areas, and freshwater rearing areas for endangered steelhead in Hilton Creek and in reaches of the Santa Ynez River that are dependent on the artificial water releases to sustain the quality and availability of designated critical habitat. We are only able to inform a general understanding of the potential effects due to reductions in water releases, based on the available information.
Therefore, while the timing, duration, amount and extent of adverse effects on designated critical habitat cannot be precisely predicted at this time, we believe adverse effects will be of limited duration and spatial extent and that the function of affected critical habitat will resume when water releases resume.
Conducting repairs to the Bradbury Dam stilling basin may require dewatering this habitat during the dry season. Based on available information, this activity would be infrequent (i.e., has only occurred one time in about 60 years) (Gruenhagen 2014, 2016). Conducting such repairs would temporarily eliminate the freshwater rearing area in the stilling basin portion (about 5 surface acres) of the Santa Ynez River. Because of the infrequent and temporary nature of this activity, we do not expect the value of designated critical habitat in this portion of the action area to diminish.
Maintenance of USGS gaging stations may result in rerouting river flow, causing formerly wetted areas to be dewatered. Because maintenance would occur during the dry season, the consequences involve a temporary reduction in available freshwater rearing area for juvenile steelhead if water is present in the affected area. The total area or length of rearing habitat that may be dewatered is unknown, but expected to be relatively small (<100 feet). A net reduction of freshwater rearing area is not expected because the river would be rerouted to an alternate course (i.e., reconnecting to gaging station intake pipes).
The potential disruption of flow in the Santa Ynez River or Hilton Creek resulting from maintenance activities is anticipated to be infrequent and temporary. After careful consideration of the potential effects to steelhead habitat, we do not anticipate the functional value of designated critical habitat will be reduced as a result of proposed maintenance of Bradbury Dam and related facilities.
2.4.1.3 Effects on Critical Habitat due to Monitoring Endangered Steelhead and Habitat Conditions
Under the proposed action, Reclamation would implement the Lower Santa Ynez River Monitoring Plan (monitoring plan) (Bureau of Reclamation 2015h). We therefore summarize the expected effects of this monitoring plan on designated critical habitat for endangered steelhead.
The presentation of effects is organized according to (1) physically installing and operating field equipment, and (2) implementing the provisions of the monitoring program. 101
Installing and operating monitoring equipment
Our review of the proposed monitoring plan identified only one element that has the potential to adversely affect designated critical habitat for steelhead: operating weirs and traps in the main stem Santa Ynez River and selected tributaries downstream of Bradbury Dam to capture migrating steelhead. Operating weirs and traps temporarily interrupts the freshwater migration corridor. However, because the weirs and traps are temporary by nature (i.e., can readily be removed) and the frequency of inspecting traps can be adjusted to reduce migration delay, we do not expect the proposed installation and operation of weirs and traps for monitoring steelhead migration to reduce the functional value of designated critical habitat in the action area for this species.
Reliance on the monitoring program to minimize adverse effects The stated objective of the monitoring plan is “to develop technical information and data on the Lower Santa Ynez River Southern California steelhead population and its habitat for use in management that supports operation of the Cachuma Project (Project) to meet its purpose while minimizing adverse effects to the Southern California steelhead.” (p. 2, Bureau of Reclamation 2015h).
In our review of this proposed monitoring plan, we found that the proposed study objectives (p. 2) lack the necessary framework to (1) reliably assess, let alone detect, effects that are attributable to the proposed action, (2) inform the development and implementation of changes to the Project operations for the purpose of minimizing effects due to the proposed action, and (3) evaluate whether the changes in operations have minimized effects on designated critical habitat (and endangered steelhead). We therefore do not expect the monitoring plan would be effective, as currently designed, in minimizing effects of the proposed action on designated critical habitat for this species. The bases for our views are described more fully as follows.
Means to reliably assess effects of the proposed action.—None of the monitoring objectives (Table 1 in Bureau of Reclamation 2015h) appear to be designed to detect effects of the proposed action because no information is given in this regard. For instance, no mention of specific quantitative response variables, inferential models, sample-size requirements, or decision or significance criteria (biological or statistical) could be found in the monitoring plan. The terminology and scope of the objectives suggest implementation of the monitoring plan would result in descriptive studies, not true evaluations of how the proposed action affects designated critical habitat. Our expectation that the monitoring plan is not useful for reliably assessing and detecting effects of the proposed action is further corroborated by the lack of proposed reference or control sites. Furthermore, the study objectives do not appear linked with specific aspects of the proposed action that would be the basis of the scientific inquiry.
Inform and implement necessary modifications to minimize adverse effects.—The proposed monitoring plan does not appear capable of assessing or detecting effects of the proposed action on critical habitat for this species.
23 For this reason, we cannot foresee that implementing the
23 As a matter of clarification, while the monitoring plan itself is not properly designed to assess or detect effects of the proposed action on habitat, biologists employed in the Cachuma Operations and Maintenance Board often obtain and then share information from routine observation of the lower mainstem that indicate consideration of Project operations may be needed to correct potentially harmful habitat conditions for this species. 102
monitoring plan would lead to changes in Project operations for the purpose of minimizing effects on the habitat. Furthermore, the monitoring plan, or even the broader proposed action, does not contain a reliable feedback process to ensure any new empirical information from the field monitoring would be used and acted upon to effect necessary changes to the operations for the benefit of endangered steelhead.
While the monitoring plan stipulates Reclamation would send NMFS annual-monitoring reports, evidence indicates the annual reports are not likely to support intentions of minimizing adverse effects, for at least a few reasons. First, because the monitoring plan itself does not appear designed to reliably assess or detect effects of the proposed action, we don’t expect the annual report to be populated with the necessary information to marshal such a perspective.
Second, even if the monitoring plan was designed to reliably assess and detect effects, the annual reports are often submitted exceedingly late to NMFS. At times, the annual reports have been sent to NMFS one or more years after monitoring was completed. Receiving annual reports years after the required monitoring has been completed is not conducive to ensuring properly functioning habitat conditions (or the long-term survival and recovery of a highly endangered species). Ideally, to address and ultimately minimize adverse effects to designated critical habitat requires timely information, even real-time data for certain parameters or metrics, to quickly identify and resolve issues in a manner deserving protection of critical habitat. This includes lapses in water releases owing to operator error and equipment malfunction.
Third, past experience reduces our confidence that changes in Project operations would be implemented. For instance, rather than changing Project operations (e.g., increasing water releases from the Project) to minimize adverse effects, the preference has been to physically remove endangered steelhead from inhospitable, or even lethal, habitat conditions that can develop in the lower river downstream of Bradbury Dam (National Marine Fisheries Service 2013b).
Evaluate the efficacy of the modifications.—The monitoring plan, and indeed the proposed action, does not stipulate effectiveness monitoring or any assurance that findings from monitoring, of any kind, will be used and acted upon to effect changes in Project operations to benefit designated critical habitat. As a result, if changes in Project operations are made, there appears to be no proposed mechanism for evaluating the efficacy of the modifications.
If adverse effects of the proposed action on designated critical habitat are to be reliably minimized in a timely way, the proposed action should incorporate a structured protocol for this purpose. In this regard, the protocol must be capable of responding to new information or changing conditions, detect and reconcile deficiencies or problems in a timely manner, and incorporate feedback loops that link implementation and monitoring to a decision-making process that results in appropriate changes in operations to benefit designated critical habitat. As currently written, the monitoring plan constitutes a plan to develop, review and consider new information, yet for an uncertain period of time and without defining a decision-making process that results in appropriate changes in operations to benefit critical habitat.
2.4.1.4 Effects on Critical Habitat due to Operation and Maintenance of the Tecolote Tunnel-South Coast Conduit
Here we analyze the expected effects of the proposed action on designated critical habitat due to (1) inspection and maintenance of the South Coast Conduit, (2) operation and maintenance of 103
South Coast Conduit regulating reservoirs, and (3) operation of Glen Annie Dam and Reservoir.
The streams with designated critical habitat intersected by the South Coast Conduit are: Glen Annie Creek, Carneros Creek, San Pedro Creek, San Jose Creek, Maria Ygnacio Creek, San Antonio Creek, Atascadero Creek, Cieneguitas Creek, Arroyo Burro Creek, San Roque Creek, Mission Creek, Sycamore Creek, Montecito Creek, San Ysidro Creek, Romero Creek, Arroyo Paredon Creek, and Carpinteria Creek.
Inspection, maintenance, and operation of the South Coast Conduit The proposed inspection and maintenance of the South Coast Conduit pipeline would result in discharging water in the above identified streams at times when natural surface water is present (Bureau of Reclamation 2015a). Inspection of the pipeline (i.e., exercising “blow-off” valves) would occur annually between November 1 and January 31, discharging 1,000 gallons or less of water at each stream location. Maintenance or repair of the pipeline would occur infrequently, on an as-needed basis, requiring the relevant segment of pipeline to be drained. This would result in discharging up to 1.5 ac-ft of water into the stream associated with the subject pipeline segment. Because the maximum rate of discharge (i.e., 0.2 cfs) is well within the natural discharge capacity of these stream channels, we do not expect discharges resulting from inspection and maintenance of the pipeline to alter physical habitat features (e.g., erosion).
However, water transmitted through the pipeline is disinfected with chlorine once it reaches the Cater Water Treatment Facility, about midway along the South Coast Conduit. Although the water is reported to undergo de-chlorination prior to discharging in streams, the biological assessment (Bureau of Reclamation 2013a) does not provide sufficient detail to determine the effectiveness of de-chlorinating water prior to release (i.e., amount of residual chlorine in discharged water). Studies of chlorine toxicity indicate exposure to even low concentrations of chlorine (e.g., 0.6 mg/l) can cause sub-lethal to lethal effects to juvenile steelhead (Cooke and Scheerer 2001). Therefore, we conclude that the proposed inspection, maintenance and repair of the South Coast Conduit is expected to temporarily reduce the quality of freshwater rearing areas in streams receiving treated-water discharge (i.e., Mission Creek, Sycamore Creek, Montecito Creek, San Ysidro Creek, Romero Creek, and Arroyo Paredon Creek).
The South Coast Conduit is typically buried below the channel bed surface of intersecting streams. However, stream discharge has exposed the pipeline in several streams that are designated critical habitat and created habitat blockages or impediments in the freshwater migration corridor (i.e., impeding or precluding upstream movement of adult and juvenile steelhead) (Table 2-10). It is also likely that stream discharge will expose the pipeline in other locations where the pipeline intersects streams. While Reclamation suggests its intent to remediate these migration impediments, neither existing nor future remediation is incorporated in the proposed maintenance. Rather, Reclamation defers remediation to an undisclosed future date, and subsequent ESA consultation, based on prioritization of operational needs (Bureau of Reclamation 2015a). Because the exposed pipeline crossing the streams represents an obstruction in the freshwater migration corridor, and this condition is expected to continue unabated due to the proposed action, we conclude the continued maintenance and operation of the South Coast Conduit will continue to reduce the function and value of the intersecting freshwater migration corridors for endangered steelhead. 104
Table 2-10. South Coast Conduit stream crossings in designated critical habitat for endangered steelhead that generally represent an obstruction in the freshwater migration corridor for endangered steelhead (source: Stoecker 2002, Cardno 2014).
Stream
Barrier severity
(Cardno 2014)1
Barrier severity
(Stoecker 2002)
Amount of critical
habitat upstream of
the conduit
Carneros Creek Gray Severe 0.0 miles
Maria Ygnacio Creek Gray High 2.7 miles
San Roque Creek Gray Low 0.2 miles
Mission Creek Red Extremely High 1.9 miles
Montecito Creek Red High 3.1 miles
Romero Creek Red not assessed 0.8 miles
1 Cardno 2014—Fish Passage Barrier Assessment of South Coast Conduit Stream Crossings “Fish-passage Barrier Severity” definitions: Gray—may be a passage barrier under some conditions and will need to be further surveyed to determine at what flows barrier is passable. Red—estimated passage barrier at all flows.
Operation and maintenance of regulating reservoirs
The three “regulating reservoirs” (i.e., Lauro24, Ortega25, and Carpinteria dams and reservoirs) are located outside of existing stream channels; these facilities do not obstruct the freshwater migration corridor. Carpinteria Reservoir is the only regulating reservoir that discharges water into critical habitat. This reservoir is drained for maintenance about once every two years, occurring for a two-day period sometime in November through January. About 2 ac-ft of water is discharged into Carpinteria Creek at a rate of 0.5 cfs over a 2-day period. The rate of discharge is within the range of minimum (0 cfs) and maximum (30, 200, and 1,450 cfs, for the respective months) average daily flow for Carpinteria Creek at the release point. Because the maximum rate of discharge (i.e., 0.5 cfs) is within the natural discharge capacity of the stream channel, we do not expect discharges resulting from maintenance of the reservoir to alter physical habitat features (e.g., erosion).
However, the water contained in Carpinteria Reservoir is disinfected with chlorine. Although the water is reported to undergo a de-chlorination process prior to being discharged in Carpinteria Creek, the biological assessment (Bureau of Reclamation 2013a) does not provide
24 Lauro Dam and Reservoir: The drainage area upstream of Lauro Reservoir is less than 300 acres and is diverted around the reservoir. The reservoir outlet is designed to discharge directly into San Roque Creek (critical habitat); however, water has never spilled or been released and is not proposed to be released into San Roque Creek (Bureau of Reclamation 2013a).
25 Ortega Dam and Reservoir: The drainage area is less than 1 acre and is diverted into a stilling basin downstream of the reservoir. The reservoir has never spilled, but is drained once every two years discharging approximately 4.0 ac-ft of dechlorinated potable water at a rate of 0.5 cfs into Greenwell Creek which is not designated critical habitat (Bureau of Reclamation 2013a).
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sufficient detail to determine the effectiveness of de-chlorinating water prior to release (i.e., amount of residual chlorine in discharged water). Studies of chlorine toxicity indicate exposure to even low concentrations of chlorine (e.g., 0.6 mg/l) can cause sub-lethal to lethal effects to juvenile steelhead (Cooke and Scheerer 2001). Therefore, we conclude that the proposed maintenance of Carpinteria Reservoir is expected to temporarily reduce the quality of freshwater rearing areas in Carpinteria Creek.
Operation of Glen Annie Dam
Glen Annie Dam and Reservoir captures and stores runoff from West Fork Glen Annie Creek watershed. The reservoir is not used for water supply or facilities operations, other than capturing water drained from the Tecolote Tunnel-South Coast Conduit during inspection and maintenance occurring about once every six years. The dam is a complete barrier to steelhead migration and is the upstream-most extent of designated critical habitat in West Fork Glen Annie Creek.
Inspection and maintenance of the Tecolote Tunnel results in discharging water diverted from Cachuma Reservoir into Glen Annie Reservoir (i.e., approximately 2 ac-ft to drain the tunnel for inspection and 18 ac-ft per day for flushing debris). Critical habitat is not expected to be affected by the proposed discharges into Glen Annie Reservoir because it is not designated as critical habitat.
Operation of Glen Annie Dam and Reservoir includes the capture, storage and release of water in West Fork Glen Annie Creek. All runoff is captured and stored in the reservoir until released through the dam outlet works. Water releases are only made in response to maintaining reservoir storage levels to comply with seismic safety regulations.26 These water releases are made at a rate of 0.45 cfs or less for a cumulative volume of less than 15 ac-ft of stored water, and conducted during periods when the stream is dry below the dam (i.e., fall). The continued operation of Glen Annie Dam and Reservoir under the proposed action alters the timing, magnitude and duration of wet-season streamflow in West Fork Glen Annie Creek and Glen Annie Creek. Streamflow in West Fork Glen Annie Creek from the dam to the confluence with main-stem Glen Annie Creek is expected to be reduced by more than 80 percent (i.e., approximately 84 % of the West Fork Glen Annie Creek subwatershed is controlled by the dam).
Based on hydrologic analysis27 incorporated in Reclamation (2013a), streamflow is reduced by 25 to 11 percent in Glen Annie Creek from the West Fork Glen Annie Creek confluence downstream to Tecolotito Creek, respectively. Because streamflow is essential for providing a functional freshwater migration corridor and spawning and rearing habitats for steelhead, the proposed operation of Glen Annie Dam and Reservoir would reduce the functional value of designated critical habitat.
26 Glen Annie Dam and Reservoir has a storage capacity of 470 ac-ft; however, maximum storage is restricted to 196 ac-ft in accordance with Bureau of Reclamation Safety of Dams seismic safety regulations (Bureau of Reclamation 2013a).
27 Draft Technical Memorandum—Estimated streamflow at facilities in the South Coast Conduit action area.
Stetson Engineering Inc. May 23, 2013.
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2.4.2 Effects on Habitats Not Designated as Critical Habitat In this section we describe the effects of the proposed action on habitats for endangered steelhead that are not currently designated as “critical habitat” under the ESA (see National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)). Although such habitats are not designated as critical habitat, such habitats provide important ecological functions to sustain growth and survival of the species. Therefore, adverse effects on such habitats may result in adverse effects on steelhead. Within the action area, such habitats involve the Santa Ynez River Estuary.
Reducing the Frequency and Duration of Estuary-Ocean Connectivity While the Santa Ynez River Estuary is not designated critical habitat for endangered steelhead28, estuaries have considerable functional value supporting the full expression of life-history pathways in this species. The Santa Ynez River Estuary is one of the largest and least physically modified estuaries within the Southern California DPS and has the potential to contribute to the support of the freshwater phase of the Santa Ynez River steelhead population (Ferren et al. 1995, Kelley 2008, ESA-PWA 2011). Yet information leads us to conclude the proposed action would continue reducing the frequency and duration that a migration corridor would form between the Santa Ynez River Estuary and the ocean.
The specific mechanism for the reduced frequency and duration involves the continued alteration of the pattern and magnitude of river discharge owing to the proposed action. Although the watershed (chiefly from Salsipuedes Creek) would on occasion produce sufficient surface runoff to breach the estuary (Cachuma Operations and Maintenance Board 2013), the proposed action is expected to continue reducing and, in certain cases, eliminating the magnitude, frequency and duration of discharge pulses (i.e., periods of elevated streamflow that are prompted by wetseason rainfall events) during winter and spring. Findings from the hydrologic analyses indicate annual peak maximum discharge would continue to be reduced in all types of water years (Table 2-2 and Figure 2-12), perhaps by as much as eighty-five percent (e.g., water year 2008). Overall, as a result of the proposed capture and storage of river inflows in Cachuma Reservoir, the ability of the river to flood during rainfall periods and occasionally cause a breach is anticipated to remain artificially diminished, as is the frequency and duration of a migration corridor between the estuary and ocean (see Jacobs et al. 2011).
2.4.3 Effects of the Action on Endangered Steelhead
In this section we analyze the effects of the proposed action on endangered steelhead due to (1) operating Bradbury Dam-Cachuma Reservoir, (2) maintaining Bradbury Dam, (3) monitoring habitat conditions in the Santa Ynez River and selected tributaries downstream of Bradbury Dam, and (4) operating and maintaining the South-Coast Conduit. Population-level consequences in the action area of the proposed action are presented in section 2.4.4 “Consequences for Steelhead Recovery and Survival in the Action Area.” Information presented earlier in this biological opinion indicates steelhead abundance is critically low in the action area, and presence of adults appears to be intermittent. These facts may not be
28 The Santa Ynez River estuary is within lands owned or controlled by the Department of Defense (i.e., Vandenberg Air Force Base) and excluded from designated critical habitat (National Marine Fisheries Service 2005 (70 FR 52488; September 2, 2005)).
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readily apparent in the following narrative of the effects, which we suspect creates the impression that steelhead are abundant and widespread. The description of effects on steelhead was written with the intention of illustrating the effects when steelhead are present. Effects of the proposed action on critical habitat for steelhead and the likelihood of survival and recovery of this species are expected regardless of the low number of steelhead projected to be present at this time and should be viewed in the context of the low abundance of individuals in the current population.
2.4.3.1Effects due to Operating Bradbury Dam
Many of the effects analyzed in this section have been derived from the analysis of how the proposed action would affect the pattern and magnitude of discharge in the Santa Ynez River, the expected effects on critical habitat, and the life history and habitat requirements of steelhead (section 2.4.1, “Effects of the Action on Critical Habitat,” largely provides the underlying basis for the analysis of effects on steelhead). The following summarizes how the proposed operations are expected to continue (1) reducing migration opportunities for adult and juvenile steelhead, (2) decreasing opportunities for spawning, incubation, and emergence, and (3) harming juvenile steelhead. Because the proposed action is essentially the same as current operations, the proposed action is projected to continue the adverse effects of the current operations into the future.
Continue to reduce migration opportunities for adult and juvenile steelhead In this subsection, we first summarize the available information indicating reduced migration opportunities for adult and juvenile steelhead under the proposed operations. Subsequently, we describe the consequences of the reduced migration opportunities for individual adult and juvenile steelhead.
For many reasons we expect the decrease in the quality and availability of the freshwater migration corridor would reduce, and occasionally eliminate, the frequency and duration of migration opportunities for adult and juvenile steelhead in the Santa Ynez River and tributaries downstream of Bradbury Dam. One reason involves the naturally elevated river discharge or “pulses” typically observed during the wet season. These would be frequently lacking and/or severely truncated due to the proposed action. As a result of the proposed action, tributaries in the lower watershed, rather than flow from the upper watershed, will principally or exclusively provide flows for steelhead emigration and immigration throughout the main-stem river (i.e., instead of combined and greater contribution of flow generated from the upper watershed above Bradbury Dam). This is significant because adult and juvenile steelhead naturally migrate during periods of elevated river discharge (Shapovalov and Taft 1954, Spina et al. 2005). As a result, the short-duration low flows that would often persist in the main stem downstream of Bradbury Dam represent an alteration of the species’ habitat (the flow-dependent freshwater migration corridor) and are not consistent with the migratory behavior and ecology of adult and juvenile migrants.
Another reason involves a recent assessment of migration opportunities for this species in the Santa Ynez River (O’Dowd et al. 2014) (Figure 2-30 and 2-31), which indicates that migration opportunities for adult steelhead would remain severely reduced under the proposed action.
O’Dowd et al. (2014) depicts the reduction in annual adult steelhead passage opportunities since Bradbury Dam operations began in about 1954 (i.e., inclusive of operations that differ from the current and proposed operations), which is relative to an estimated unimpaired condition. This 108
trend is consistent with the findings of Reclamation (2013a) and our own (e.g., Figure 2-18, Table 2-4) regarding the effects of the proposed action. In addition, these findings indicate the existing effects of the current operations would continue under the proposed action.
Figure 2-30.—Adult steelhead passage opportunity losses of the lower bound line in the Santa Ynez River at Solvang (about 40 miles upstream from the ocean) resulting from construction and operation of Bradbury Dam (1954 to present) and Gibraltar Dam (1920 to 1953) relative to an estimated unimpaired flow regime (source: O’Dowd et al. 2014). A passage-day occurs when daily mean discharge is ≥63 cfs. 109
Figure 2-31.— Adult steelhead passage opportunity losses of the lower bound line in the Santa Ynez River at Lompoc (about 10 miles upstream from the ocean) resulting from construction and operation of Bradbury Dam (1954 to present) and Gibraltar Dam (1920 to 1953) relative to an estimated unimpaired flow regime (source: O’Dowd et al. 2014). A passage-day occurs when daily mean discharge is ≥101 cfs.
There is further evidence of the expected reduction in the frequency and duration of migration opportunities for steelhead, specifically adult immigrants. We qualitatively examined a record of past hydrologic conditions, and related migration opportunities, over three years representing a range of hydrologic conditions (i.e., 2008, 2009 and 2010) (Figure 2-21). We reviewed this information as an indication of future conditions under the proposed action (e.g., Table 2-4).
The results of this analysis for each of the three years follows. Collectively, the results support the expectation that decreases in migration opportunities can translate into fewer observations of adult immigrants.
Water year 2008 was an above normal to wet year, with uncontrolled spills of water at Bradbury Dam, providing opportunities for adult steelhead immigration. Hydrologic conditions resulted in overlapping discharge pulses well above suggested minimum passage flows for more than 45 continuous days (Table 2-4). However, the current and proposed operations artificially truncated the total migration and passage opportunities; the number of days meeting suggested minimum passage flows (i.e., ≥25 cfs and ≥63 cfs) were reduced by 47 and 43 percent, respectively.
Sixteen adult steelhead were observed (Bureau of Reclamation 2011c), the most observed in the Santa Ynez River during the last 20 years (Bureau of Reclamation 2013a).
In water year 2009, considered a dry year, no adult steelhead was observed in the Santa Ynez River or tributaries (Cachuma Operation and Maintenance Board 2012). We recognize that dry years, in general, experience naturally reduced magnitude, frequency and duration of discharge pulses. However, the naturally limited discharge in 2009, and consequently the opportunity for adult steelhead to migrate in the Santa Ynez River, was exacerbated, if not eliminated, by the current and proposed operations of Bradbury Dam (Figures 2-20 and 2-21). The number of days meeting suggested minimum passage flows (i.e., ≥25 cfs and ≥63 cfs) were 3 days and 1 day, 110
respectively; a reduction of by more than 90 percent (Table 2-4). Applying an anticipated migration rate of 5 miles/per day (Bureau of Reclamation 2013a, O’Dowd et al. 2014), adult steelhead would not be expected to reach spawning habitat in the main-stem river between Solvang and the dam or tributaries such as Hilton Creek or Quiota Creek.
Water year 2010 was an above normal to wet year, but Bradbury Dam did not spill. Another feature of this water year involved the operation of the dam, which included Reclamation’s passage-flow supplementation release that is specifically intended to reduce impacts of operating Bradbury Dam on adult steelhead migration. Even with implementation of water releases to reduce impacts on steelhead passage, the number of days meeting suggested minimum passage flows (i.e., ≥25 cfs and ≥63 cfs) were reduced by 48 and 73 percent, respectively (Table 2-4).
Although 2010 was similar to 2008 based on water-year type, the current and proposed operations of Bradbury Dam profoundly altered the pattern and magnitude of discharge pulses (Figures 2-21 and 2-25). As opposed to 2008 when the reservoir spilled, all inflow was captured in the reservoir in 2010 with migration and minimum-passage opportunities reliant on tributary inflow downstream of the dam rather than discharge contributed from the watershed above the dam. This resulted in poor migration opportunities comprised of low-magnitude discharge pulses that occasionally and briefly exceeded the suggested minimum passage flows (e.g., 63 cfs), whereas projected discharge absent of current and proposed operations would have provided flows greater than 100 cfs continuously from mid-January through mid-March. This apparently is the basis for Reclamation’s conclusion that flow conditions in the Santa Ynez River were not conducive for anadromous steelhead migration in water year 2010, with only a few moderate flow events in the winter and spring (Bureau of Reclamation (2013d). Only one adult steelhead was observed during the 2010 migration season (Bureau of Reclamation 2013d).
Until now, we have summarized information that indicates the proposed action would translate into reduced and occasional elimination of migration opportunities for steelhead, with an emphasis on adult immigrants. Because the migratory behavior and ecology of steelhead evolved under the naturally variable flow regime (e.g., Lytle and Poff 2004), the life history and habitat characteristics of steelhead depend on features of the unimpaired flow regime (e.g., the natural timing, magnitude, duration, frequency, and rate of change of streamflow). The substantial continued departure of river discharge, due to the proposed action, from the “unimpaired” pattern and magnitude of river discharge is harmful to steelhead in the Santa Ynez River. We note that the occasional shift in the timing of water releases from the dam as particularly problematic for adult-steelhead migrants, given the species’ dependency on naturally elevated river discharge during winter and spring to provide environmental cues for migration as well as facilitate volitional movement of fish. In the following paragraphs, we describe the expected consequences of the reduced migration opportunities for adult steelhead.
The proposed action would reduce the frequency and duration that adult steelhead would be able to volitionally enter the Santa Ynez River Watershed and begin their up-river journey. Despite the occasional wet-season runoff (primarily owing to Salsipuedes Creek) that is sufficient to breach the sandbar forming the estuary, the proposed action would continue capturing most of the flood flows that can initiate and maintain estuary-ocean connectivity. In turn, the incidence and length of time that a suitable migration corridor naturally forms and remains between the estuary and ocean in winter and spring each year will remain artificially diminished due to the proposed action.
If they enter the watershed, the in-river journey of adult steelhead has the potential to be 111
impaired or halted owing to a variety of factors related to the proposed action. One factor involves the quickened rate that the river recedes downstream of the dam. In this regard, we are not referring to proposed ramping rates of controlled water-releases from the dam, rather the loss of inflow from the watershed upstream of the dam that would otherwise reduce the rate of recession in river flow downstream of the dam. This increases the risk that adult migrants would be stranded or exposed to conditions that do not favor survival.
Another factor involves the proposed minimum-water releases for “passage” or movement from one adjacent mesohabitat to another. The minimum-passage releases only account for the smallest needs of the species for physically navigating through the water column; they do not provide the essential environmental cue that initiates and facilitates effective migration. In addition, the minimum-passage releases owing to the proposed action produce water columns depths that appear unsuitable for adult steelhead to move about safely in the river main stem (O’Dowd et al. 2014). The proposed action lacks the sorts of water releases that are needed to create and maintain pools (Harrison et al., in revision), which adult steelhead use during migration. Overall, aspects of the proposed action increase the potential that steelhead would be unable to safely and efficiently migrate upstream and downstream in the river main stem.
The foregoing conclusion contrasts with NMFS’ former biological opinion, which generally anticipates Reclamation’s supplemental migration releases would “…significantly increase successful migration by steelhead…” (p. 40, National Marine Fisheries Service 2000). However, since the former analysis, we have had the benefit of observing implementation of the supplemental migration releases and the practical influence of the supplemental releases on river hydrology. Now, several years following implementation of these releases, the current analysis examines how the supplementation would influence river discharge and related habitat characteristics. As explained more fully in section 2.4.1, Effects of the Action on Critical Habitat, of this biological opinion, the supplemental releases are inadequate for promoting a freshwater migration corridor in the Santa Ynez River. Another difference between the former and current analyses is the former analysis considers whether the supplemental releases would increase migration opportunities relative to the environmental baseline, which includes the past and existing effects of project operations. In contrast, the current analysis properly considers that the proposed action would continue the effects of the existing project operations on river discharge into the future.
The continued conflict between in-river beaver dams and steelhead migration represents another factor. There is no reason to expect this conflict, and related steelhead migration challenges, would be remediated in any meaningful way under the proposed action. We make this determination based on aspects of Reclamation’s beaver-control plan (Bureau of Reclamation 2015i). In particular, this plan is admittedly experimental and generates many uncertainties. The plan lacks any assurance that the proposed activities would be undertaken (no proposed schedule could be found in the plan, and the term “may” is often appended to the proposed modification and removal activities), let alone prove effective. The plan is spatially limited in scope with only a relatively short stretch of the main-stem river accessible to Reclamation; therefore, a number of beaver dams would remain in place throughout most of the river, despite the potential for Reclamation to undertake dam-modification or removal efforts in accessible reaches. Effecting proposed desiccation of certain downstream reaches in select years to reduce the beaver population would produce only temporary consequences (not to mention the adverse effects on any steelhead holding in the dewatered area). In addition, the plan does not address the impacts 112
of the proposed action that ultimately amplify the influence of the beaver dams on migration of adult steelhead. In this regard, the plan does not mitigate the effects due to the continued capture and retention of most high flows that are capable of scouring the beaver dams from the river channel.
We expect the foregoing effects greatly increase the potential that migration of adult steelhead would continue to be disrupted or delayed. If disruption or delay is encountered, we anticipate that, at a minimum, the affected individuals will experience harm. The distance traveled upstream and arrival time at spawning areas has ecological significance and can lead to use of non-preferred spawning habitats and decreased recruitment, and preclude individuals from reaching spawning areas (Fleming and Reynolds 1991, Dickerson et al. 2005, Caudill et al. 2007). Overall, the proposed action increases the risk that adult steelhead would be prevented from reaching intended habitats and experience migration failure, and consequently reproduction failure, in most years.
While the proposed action includes conservation water releases to, in part, extend the duration of migration opportunities for adult steelhead, our review29 indicates the proposed operations (including the conservation releases) would do little, if anything meaningful, to offset the continued effects of operations. Reclamation corroborates this conclusion with their finding that flow conditions in the Santa Ynez River were not conducive for adult steelhead migration and spawning during winter and spring of 2010, even though such water releases were implemented (Figure 2-32) (Bureau of Reclamation 2013d). Furthermore, our review of the decision (triggering) criteria for the proposed conservation water releases, indicates a low likelihood the releases would be implemented in a given year (see Table 2-11 for a review of the criteria deficiencies). The proposed action would extend into the future the existing operations; these operations annually capture a large amount of inflow, on average, and annually release a quantity of water for conservation of endangered steelhead that is on average quite small (Figure 2-33).
Overall, as a result of the proposed action, tributary inflow in the lower watershed will continue to be the principal source of flows to create and sustain migration opportunities for adult steelhead in the river main stem downstream of Bradbury Dam. As we have described, this reliance on tributary flows as a result of the proposed action, in turn, results in a large reduction of steelhead migration opportunities in the Santa Ynez River.
29 The hydrologic analyses that are the basis of section 2.4.1, Effects of the Action on Critical Habitat, incorporate the proposed “conservation releases.”
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Figure 2-32.—Daily mean discharge in Santa Ynez River, Solvang, from January 1 through May 31 in water year 2010 under two conditions: “Without Current or Proposed Bradbury Dam Operations” (i.e., available discharge without present and proposed operations of Bradbury Dam), “Current/Proposed Operation” (i.e., discharge due to current operation and expected discharge resulting from Reclamation’s proposed operating criteria). “Bradbury Dam Releases” depicts conservation water releases intended to supplement tributary inflow for the purpose of adult steelhead migration.
0 100
200
300
400
500
600
700
800
900
1000
1/1/20101/8/2010
1/15/20101/22/20101/29/2010
2/5/2010
2/12/20102/19/20102/26/2010
3/5/2010
3/12/20103/19/20103/26/2010
4/2/20104/9/2010
4/16/20104/23/20104/30/2010
5/7/2010
5/14/20105/21/20105/28/2010
Discharge (cfs)
Without Current or Proposed Bradbury Dam Operation
Current/Proposed Operation
Bradbury Dam Releases (cfs)
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Table 2-11. Summary of the deficiencies and implications due to Reclamation’s proposed decision criteria for triggering passage-supplementation water releases from Bradbury Dam. The intended purpose of the releases is to increase migration opportunities in the main stem Santa Ynez River for adult steelhead.
Decision criteria Deficiency Implications for adult steelhead Cachuma Reservoir must fill
and spill ≥20,000 ac-ft of
water to establish the Fish
Passage Account.
Criterion reduces the likelihood that the Fish Passage Account would frequently be established. Spills are dependent on available storage, which is affected by reservoir operations including water withdrawals to support domestic water users within and outside the watershed. As many as 8 consecutive years between spills has occurred since Cachuma Reservoir was established.
Reduces likelihood of water release from
Bradbury Dam to improve passage
conditions. This life stage would continue
experiencing a profoundly altered
freshwater migration corridor and related
consequences.
The Fish Passage Account
limited to 3,200 ac-ft.
The amount of water allocated for fish-passage water releases is not sufficient. The Fish Passage Account is exhausted after supplementing only two discharge pulses (Bureau of
Reclamation 2011d and e); most potential steelhead-migration opportunities would not be supplemented. The likelihood that discharge pulses would be supplemented is low because the account would not likely be replenished before subsequent discharge pulses within and between years.
Reduces likelihood of water release from
Bradbury Dam to improve passage
conditions. This life stage would continue
experiencing a profoundly altered
freshwater migration corridor and related
consequences.
The storm to be
supplemented with passageflow water releases is within the migration season of
January to May.
Criterion does not fully account for the entirety of the steelheadmigration window (e.g., Fukushima and Lesh 1998). Affects timing of water releases.
Artificially truncates the natural migration
season for this life stage.
Discharge in the main-stem
river measured at the
Solvang gage must be ≥ 25
cfs.
Because operation of Bradbury Dam alters the pattern and diminishes the magnitude of river discharge, the frequency and duration this criterion would be met is artificially reduced.
Perpetuates existing effects of Bradbury
Dam operations on the quality and
availability of the freshwater migration
corridor and migration opportunities for
adult steelhead.
Accumulation of daily
average discharge since
December 1 at the
Salsipuedes Creek USGS
gage is ≥ 1,000 AF.
Criterion reduces the likelihood and timing of water releases from Bradbury Dam for migration. Ignores the role of discharge pulses in cuing and facilitating migration of steelhead, including establishing groundwater and surface water conditions (e.g., connectivity) to make subsequent discharge pulses more
effective for migration.
Criterion is insensitive to the migratory
behavior and ecology of steelhead, which is
strongly associated with naturally elevated
river discharge in winter and spring. Adult
steelhead experience reduced or no
migration opportunities.
The sandbar at the mouth of
the estuary must be
breached.
Criterion perpetuates existing effects of Bradbury Dam
operations on the quality and availability of the freshwater migration corridor. The operation of Bradbury Dam alters the frequency and duration of breaching, hence the frequency and duration this criterion would be met is artificially reduced.
Reduces likelihood of water releases from Bradbury Dam to create meaningful migration opportunities.
Adult steelhead experience reduced or no
migration opportunities (including
watershed access) in the main-stem river
downstream of Bradbury Dam.
The first storm in January
will not be supplemented.
Contradicts Reclamation’s decision criterion involving the seasonal migration window for steelhead. Ignores the natural role of discharge pulses in cuing and facilitating migration of steelhead, including establishing groundwater and surface water conditions (e.g., connectivity) to make subsequent discharge pulses more effective for migration. Reduces likelihood of water releases from Bradbury Dam to create meaningful migration opportunities.
Criterion insensitive to the migratory
behavior and ecology of steelhead, which is
strongly associated with naturally elevated
river discharge in winter and spring. Adult
steelhead expected to experience reduced or
no migration opportunities.
Supplement water releases
unless: (a) flows at Solvang
reach 25 cfs within the 7
days following a prior
migration flow release, (b)
the decision group
determines greater
biological benefit not to
supplement, or (c) there is
no water remaining in the
Fish Passage Account.
Criterion perpetuates existing effects of Bradbury Dam
operations on the quality and availability of the freshwater migration corridor. Increases potential that river discharge is maintained at relatively low levels. Ignores the natural role of discharge pulses, including successive pulses, in cuing and facilitating migration of steelhead. Assumes passage
requirements will meet migration requirements.
Migration opportunities for adult steelhead
remain artificially truncated.
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Figure 2-33.—Comparison of the average annual amount of inflow to Cachuma Reservoir (top of bar = 118,994 af, N=20) versus the average annual amount of water released for conservation of endangered steelhead (top of bar = 3,683 af, N=20) into the Santa Ynez River downstream of Bradbury Dam for water years 1993 through 2012 (source: Bureau of Reclamation 2013a).
Furthermore, the continued operation and maintenance of Bradbury Dam under the proposed action prevents endangered steelhead from accessing historical spawning habitats upstream of the dam, and reduces efficient interchange between the resident form and the anadromous form, as well as limiting juveniles currently found above the dam from migrating to the ocean. These are considered adverse effects given the value of the historical habitats and role of the resident form to the viability of the anadromous form of O. mykiss (National Marine Fisheries Service 2012c). Continued maintenance to preserve the operational capacity of the dam and reservoir and related operation of the dam, as expected under the proposed action, would carry on the existing obstruction in the steelhead migration corridor and continue reducing the amount of habitat for this species (Alagona et al. 2012). Continued operation of the dam without provision to reconnect anadromy to historical habitats has the functional effect of causing fragmentation of the species’ habitat. Habitat fragmentation can have catastrophic consequences for native aquatic organisms, including population extinction (National Research Council 1996, Morita and Yamamoto 2002, Rieman and McIntyre 1993, Dunham et al. 1997). 0 10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
110,000
120,000
INFLOW (AF) RELEASE FOR ENDANGERED
STEELHEAD (AF)
Amount of Water (AF)
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This is particularly concerning for at least a few reasons:
1) The portion of the Santa Ynez River Watershed downstream of Bradbury Dam alone is not expected to be capable of supporting a viable steelhead population according to at least two steelhead ecologists (SWRCB 2012a and b).
2) Recent modeling efforts conclude that potential over-summering habitat for juvenile steelhead is available upstream of the dam (Boughton and Goslin 2006), much of which is expected to be perennial and within thermal tolerances for the species (Shapovalov 1944) even during dry years (Boughton 2013); these individual sub-basins and constituent habitats therein are expected to buffer the species against the effects of extended drought.
3) The Santa Ynez River Watershed steelhead population is one of the most import population units and critical to the survival and recovery of the Southern California steelhead DPS (National Marine Fisheries Service 2012c).
As revealed in the paragraphs that follow, the loss and reduction of migration opportunities are expected to have adverse effects on juvenile migrants too. The basis for this expectation is reviewed in the section 2.4.1, “Effects of the Action on Critical Habitat.” Principally, the underlying causes for the adverse effects on juvenile migrants involve decreasing the amount and extent of surface flow, and disrupting surface-flow connectivity, including hydrologic synchrony, within the main-stem river, tributaries, and estuary during the spring and fall emigration season for this specific life stage (for review, see Figures 2-21 and 2-22). Before getting into this consideration, there are a few basic concepts the reader should understand at the onset.
First, the variety of life-history pathways that juvenile steelhead express in nature must be supported for large numbers of individuals to reach the smolt stage and for the population as a whole to perpetuate its natural biological diversity. Generally, these pathways involve the different ways in which juvenile rear, grow, and survive in a watershed (e.g., Hayes et al. 2008).
Central to these pathways is the ability of juvenile steelhead to undertake volitional movement, occasionally of long distance, between and among habitats within a watershed. These movements can involve departing upstream reaches, including tributaries, for downstream reaches or the estuary, and leaving the estuary or downstream reaches for upstream reaches, including tributaries (Shapovalov and Taft 1954, Bramblett et al. 2002, Hayes et al. 2008, Hayes et al. 2011). Hydrologic connectivity and the related linkages between and among habitats must be present to promote these volitional movements.
Second, expression of these life-history pathways is exceedingly important because they confer a survival advantage, not only to this specific life stage, but to smolt and adult stages. For example, investigators have found that the ability of juvenile steelhead to access seasonal habitats can confer greater growth (e.g., Bond et al. 2008, Hayes et al. 2008, Hayes et al. 2011) and increase the probability that individuals would reach or exceed the size threshold for marine survival (i.e., larger smolts have a better chance of surviving in the ocean and return to freshwater and spawn as an adult) (Ward et al. 1989, Bond et al. 2008). With these concepts in mind, we move to a description of how the proposed action would affect migration opportunities for juvenile steelhead downstream of Bradbury Dam.
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The proposed action would continue abbreviating the seasonal window for entry of juvenile steelhead into the ocean. Wet-season rainfall in the Santa Ynez River Watershed may occasionally generate sufficient river discharge to provide a viable migration corridor through the river and between the estuary and ocean (primarily from contribution of Salsipuedes Creek Watershed), even with the proposed action. However, more frequently the proposed action would capture most of the flood flows that can create and maintain the migration corridor. This would reduce the occurrence and duration that the river provides a suitable migration corridor and the estuary is open to the ocean. For this reason, under the proposed action, juvenile steelhead are expected to experience far fewer opportunities, of shorter duration, to access the ocean in a given year.
In addition to shortening the window for juveniles to enter the ocean, the proposed action is expected to continue terminating opportunities for ocean entry sooner in a given year. This expectation is based on a few factors. First, the available information indicates the proposed operations of Bradbury Dam would lead to earlier formation of the sand bar and the estuary has been observed to close much earlier than the breadth of the seasonal downstream migration of juvenile steelhead (see Table 4B-4 in Bureau of Reclamation 2013a). Second, the seasonal breadth of the window for juvenile steelhead to enter the ocean appears to be positively related to the duration that the estuary is open (Bond et al. 2008, Hayes et al. 2008). Therefore, causing the sand bar to form earlier in a given year is projected to shift the timing of ocean-entry opportunities.
To gain additional insights about how the proposed action would affect migration opportunities for juvenile steelhead downstream of Bradbury Dam, we reviewed recent flow data representing the emigration period for juvenile steelhead and smolt-trapping data (Cachuma Operation and Maintenance Board 2013). Although these data represent recent past operations of the Cachuma Project, they are useful for predicting the effects of the proposed action because the proposed action is similar to the recent past operations.
Our review indicates that the hydrologic discontinuity documented for the river main stem in spring can create poor migration conditions for juveniles entering the main-stem river from joining tributaries. This is supported by the trapping data. These data show a decline in the number of downstream migrants between the two trapping locations (a distance of about 7 miles between each location) in the Santa Ynez River immediately downstream of Bradbury Dam (Table 2-12). Even at low flows, the increased duration and distribution of low-water velocities through and between pool, run and glide, comprising most of the Santa Ynez River, can decrease migration rates of juvenile steelhead (Tiffan et al. 2009). Overall, we conclude that the proposed action will continue disrupting migration opportunities that are essential to sustain the life history of juvenile steelhead.
The arrival of autumn and related environmental conditions can trigger certain flow-related behaviors in juvenile steelhead. These behaviors include undertaking migrations or movements within a watershed. We therefore shift our consideration to the consequences of the proposed action on migration opportunities in fall for juvenile steelhead. These consequences are informed from our understanding of how the proposed action would affect designated critical habitat for endangered steelhead, and our knowledge of the behavior and ecology of juvenile steelhead.
As a basis for the information that follows, autumn conditions can prompt juvenile steelhead to 118
leave tributaries and then enter main-stem reaches (Bramblett et al. 2002), move downstream within river main stems (Spina et al. 2005), and move upstream from an estuary to main-stem reaches before winter storms breach the sand bar (Hayes et al. 2011). However, aspects of the proposed action would continue to adversely affect autumn migration opportunities for this life stage. In particular, we anticipate the proposed action would (1) preclude opportunities for juvenile steelhead to volitionally access certain main-stem reaches downstream of Bradbury Dam, and (2) negate the benefits of naturally created opportunities. We explain in greater detail below.
Hydrologic connectivity is a prerequisite for juvenile steelhead traveling from tributaries to main-stem reaches. However, as indicated in our description in section 2.4.1 of the effects of the action on critical habitat, we expect the proposed operation of Bradbury Dam would continue to result in hydrologic discontinuity. For instance, negligible surface flow is expected in portions of the main-stem reach (e.g., 2.5 cfs flow target at Hwy 154). In addition, the minimum water releases and related target flows that are the basis of the proposed action increase the potential for certain reaches to experience surface-flow interruption. Further, the “Highway 154 Reach” would experience no flow due to the proposed critical-drought operations and the proposed dewatering to control non-native aquatic nuisance species throughout the main-stem river.
Effects of the proposed action in combination with the interrelated activity groundwater pumping would result in further loss of surface flow downstream of Hwy 154.
Although autumn freshets are infrequent, they can create opportunities for juvenile steelhead to access certain main-stem reaches; we expect the proposed operation of Bradbury Dam would negate the anticipated benefits of the freshets. If juvenile steelhead leave tributaries or the estuary and enter main-stem reaches downstream of Bradbury Dam during freshets, we expect individual steelhead would encounter habitats that are short lived, owing to foregoing effects of the proposed action. This is particularly true for main-stem reaches downstream of Highway 154. None of the proposed water releases that are intended to benefit conservation of endangered steelhead are specifically tied to the autumn (or spring) behavior and ecology of juvenile steelhead.
Another factor that decreases migration opportunities for juvenile steelhead in the river main stem involves the continued disruption of natural habitat-forming processes due to the proposed action. Increased frequency and persistence of beaver dams owing to decreased flood peaks and associated encroachment of woody riparian vegetation has been documented in the Santa Ynez River (Bureau of Reclamation 2013a, Cachuma Operation and Maintenance Board 2013) and other rivers (Gibson and Olden 2014) as a consequence of dam operations. However, the proposed action has no provision for establishing or approximating a natural pattern and magnitude of river discharge that would ameliorate the effects of beaver dams, in a natural manner, on juvenile steelhead migration opportunities downstream of Bradbury Dam. Similarly, the proposed action lacks the elevated water releases that are necessary to create and maintain pools (Harrison et al., in revision), which juvenile steelhead are known to use. 119
Table 2-12. Comparison of the total number of juvenile steelhead captured in downstream-migrant traps at Hilton Creek and about 7-miles downstream at the Santa Ynez River trap (source: Cachuma Operation and Maintenance Board 2013). Overall, these data indicate significantly fewer smolts are reaching the downstream trap. Along with trapping efficiency, the number of days the trap was operated is presented within the parentheses.
Water-year Trap site Trapping period Trapping efficiencya Number of juvenile steelheadb
2006 Hilton Creek Jan 16-May 27 95% / (125) 272 / (214) 2006 Santa Ynez River Feb 28-April 3 94% / (33) 14 / (14) 2007 Hilton Creek Jan 29-May 24 97% / (111) 599 / (138) 2007 Santa Ynez River N/A N/A N/A
2008 Hilton Creek Jan 7-May 14 91% / (116) 300 / (83)
2008 Santa Ynez River Feb 7-April 7 67% / (40) 1 / (1)
2009 Hilton Creek Jan 19-May 9 98% / (108) 304 / (110)
2009 Santa Ynez River Feb 17-May 9 100% / (82) 3 / (2)
2010 Hilton Creek Jan 23-May 20 95% / (111) 151 / (46)
2010 Santa Ynez River Jan 27-May 20 97% / (110) 28 / (24) 2011 Hilton Creek Jan 6-Jun 9 92% / (140) 140 / (59)
2011 Santa Ynez River Jan 6-Jun 9 72% / (110) 16 / (14) a
Trapping Efficiency is the percent of functional trapping days within the trapping period (e.g., trap may be removed during periods of high flow).
b
Smolts (presented within parentheses) were enumerated based on observed characteristics of individual fish; individual steelhead not identified as a smolt at the time of capture may subsequently transform and demonstrate these characteristics and behavior. For example, juvenile steelhead captured at the Hilton Creek trap identified as “residents” (i.e., not smolt) were subsequently identified as “smolts” upon recapture at the SYR Mainstem trap (Cachuma Operation and Maintenance Board 2013).
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Continue to reduce opportunities for spawning, incubation and emergence Adult steelhead that are able to enter and migrate through the Santa Ynez River are not expected to encounter main-stem river conditions that favor spawning. The channel bed is reported to be coarse (Denton 1989), with no observable extensive areas of suitable size substrate for spawning (i.e., gravel or small cobble) (Bureau of Reclamation 2013a). These observations are not unexpected because Bradbury Dam traps sediment that would otherwise replenish the downstream reaches with gravels and small cobble. Trapping sediment can cause a reduction in areas that could be expected to support construction of redds, resulting in decreased abundance of young salmonids (Ligon et al. 1995). More recently, the 10-mile reach immediately downstream of Bradbury Dam was characterized as having limited suitable spawning sites and an abundance of surficial sand and smaller particle types (Bureau of Reclamation 2013a). Prior to construction and operation of Bradbury Dam, this reach was characterized as providing “excellent” steelhead spawning habitat (Shapovalov 1946, as cited in Titus, et al. 2010).
Deposition or intrusion of fine sediments in steelhead nests can be detrimental to the survival of embryos and emergence of fry (Bjornn and Reiser 1991).
Migration corridors are generally not suitable locations for spawning; nests constructed downstream of the dam would be susceptible to the scouring effects from the occasional high flows or spills of water at the dam. In unimpaired waterways, adults can migrate into the extreme fringes of the watershed, including small tributaries, where flow-related characteristics and channel-bed conditions are well suited for production of young. These characteristics and conditions reduce the risk of channel-bed scour and nest destruction (Montgomery et al. 1999, and references therein). Although there are numerous tributaries to the main-stem river downstream of the dam, the vast majority of historical spawning tributaries in the watershed now lie upstream of Bradbury Dam. Furthermore, tributaries downstream of the dam appear limited in the extent of habitat suitable for spawning, incubation and emergence with 86 percent of the habitat evaluated classified as poor or fair30 (Santa Ynez River Adaptive Management Committee 2009). Unfortunately, the proposed action would continue blocking adult steelhead from more abundant historical spawning areas.
Aspects of the proposed action do not promote the sorts of flow-related spawning habitat characteristics and conditions that are appropriate for adult steelhead downstream of Bradbury Dam. We review a few of these aspects below.
First, the preferred water depth and velocity for spawning steelhead are >0.78 feet and 1.3 to 3.0 feet/second (Bjornn and Reiser 1991). But, the proposed action is neither expected nor intended to attain these depth or water-velocity criteria. Measured discharge-to-depth and velocity relations reported for Santa Ynez River habitats utilized by spawning steelhead (e.g., riffles and runs) indicate these criteria are generally not met until flows are >50 cfs (SYRTAC 1999).
Second, past assessments of water-related habitat conditions for steelhead in the Santa Ynez River (SYRTAC 1999) have only reported maximum depth and average velocity in the thalweg (i.e., deepest portion of channel). Because the preferred water depth and velocity for steelhead spawning only begins to be attained at river discharges of 50 cfs or more, steelhead spawning
30 Criteria for this habitat classification included habitat structure with fair having some spawning habitat and poor having no spawning habitat.
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would be confined to a narrow margin of the channel near the thalweg when river discharge is about 50 cfs or less. Nests constructed in or near the channel thalweg are at higher risk of being destroyed during subsequent discharge pulses due to increased scour potential in this area of the channel bed. When we examined hydrologic data for years when spawning was observed or likely to occur (i.e., 2006, 2008, 2010 and 2011), we observed that river discharges were <50 cfs during most of steelhead spawning season as a result of the current and proposed operations of Bradbury Dam (Figures 2-24 and 2-25). For example, the discharge pulse occurring in February 2010 (Figure 2-23) indicated that steelhead arriving to spawn in the 10-mile reach downstream of Bradbury Dam would have encountered flows of ≤32 cfs, assuming a migration rate of 5 miles/day following the peak of the discharge pulse (Bureau of Reclamation 2013a, O’Dowd et al. 2014). This is in contrast to an estimated discharge of 240 cfs absent current or proposed operations of Bradbury Dam that would naturally provide water depths and velocities preferred for spawning over a broader segment of the river channel (i.e., away from the thalweg).
Third, the relatively rapid decline of river discharge downstream of the dam is another factor that influences the quality and availability of spawning, incubation, and emergence areas. This is because proposed flow releases will either reduce spawning habitat to small areas near the channel thalweg, or during higher flow pulses encourage steelhead to spawn in areas that are likely to become dewatered when higher flows end. Regarding this latter point, should steelhead reach main-stem spawning areas during periods of elevated flows (e.g., when Bradbury Dam is spilling high discharges of water, such as 2008), nest construction and mating are expected. But, given the elevated flows at the time of nest construction, we expect steelhead would construct nests remotely from the thalweg. Steelhead nests constructed in such areas would experience an increased risk of dewatering prior to emergence of the young due to the proposed action because of the increased discharge recession and corresponding reduction in channel-bed inundation between nest construction and fry emergence (e.g., Figure 2-23, 2008).
Lastly, an assessment of spawning habitat conducted after construction and operation of Bradbury Dam found that river discharge ≥100 cfs (based on water depth and velocity) provided the “optimum” amount of suitable spawning habitat in the Santa Ynez River from Bradbury Dam downstream to Buellton (Denton 1989). And, a more recent assessment found that river discharges necessary for providing good quality steelhead spawning habitat in this reach range from about 200 cfs to 550 cfs (Figure 2-19) (O’Dowd et al. 2014). However, the proposed action does not propose a magnitude of water releases that would result in ≥100 cfs throughout spawning areas downstream of the dam. For example, river discharges downstream of Bradbury Dam result almost exclusively from tributary inflow with occasional water releases from the dam intended to supplement passage of adults through the main stem river during their spawning migration or high-magnitude spills from the dam; however, the hydrologic record indicates that river discharges ≥100 cfs are infrequent and of short duration resulting from the proposed action (e.g., Figures 2-23, 2-24, and 2-25). Furthermore, neither the aforementioned assessments nor the proposed action consider river discharge rates that may be necessary to flush surface and subsurface fine sediments (e.g., silts and sand-sized particles) for maintaining suitable spawning substrate. For example, Harrison (2014) suggests a peak discharge of 1,300 cfs to flush surficial sands from this reach of the Santa Ynez River, and a peak discharge of about 6,000 cfs to periodically flush subsurface silts and sands.
Through the disruption of the natural habitat-forming processes, the proposed action would continue reducing the quantity and quality of potential spawning sites in the main-stem river. 122
For instance, encroachment of vegetation in the river channel is expected to continue (Denton 1989, Bureau of Reclamation 2013a, O’Dowd et al. 2014) and challenge spawning opportunities for steelhead (Merz et al. 2008). The lateral extent and total area of river with suitable substrate, depth and velocities to promote spawning (i.e., magnitude and duration of discharge) would continue to be reduced. Artificially reduced flows and encroachment of vegetation in river channel are expected to concentrate spawning near the river thalweg, increasing the likelihood of redd scour. In addition, Denton’s 1989 study concludes that suitably sized substrate for spawning (gravel and small cobble) is in limited supply downstream of Bradbury Dam, but gravel augmentation could greatly increase the availability of spawning habitat (Denton 1989).
In addition to the foregoing effects to steelhead spawning success, the interrelated action of stocking rainbow trout in Cachuma Reservoir potentially increases risk to the genetic integrity of native steelhead downstream of Bradbury Dam. Hatchery rainbow trout can disperse from the reservoir to the Santa Ynez River main steam and tributaries when Bradbury Dam spills (Bureau of Reclamation 2013a). At least some introgression of hatchery trout has been observed in the Hilton Creek native steelhead sub-population (Garza and Clamento 2014), but introgression and reproduction of hatchery trout is essentially absent from other Santa Ynez River steelhead subpopulations (Garza and Clamento 2007).
Although Reclamation’s description of this interrelated activity identifies stocking of both sterile and non-sterile trout (Bureau of Reclamation 2013a), the California Department of Fish and Wildlife now requires all trout stocked in Cachuma Reservoir to be sterilized and tagged. Our expectation is that only sterilized trout will be used for all future stocking in Cachuma Reservoir, therefore, risk of genetic introgression from hatchery trout in the native steelhead owing to this interrelated activity would be avoided.
Continue to harm juvenile steelhead
We now explain how the proposed action is expected to harm31 juvenile steelhead. In doing so, we relate the consequences of the effects reviewed earlier in this biological opinion to growth and survival of this life stage. We do this from the perspective of the surviving embryo incubating in a gravel nest to the smolt at entry into the ocean (i.e., “egg-to-smolt survival”).
Understanding how Reclamation’s proposed action affects egg-to-smolt survival is important because the anadromous life history of this species is dependent on habitats within a watershed that produce large smolts (in sufficient abundance) (e.g., Ward et al. 1989). A watershed that produces a lesser number of predominately small smolts is not expected to result in many returns of adult steelhead. In contrast, a watershed that generously produces sizeable smolts, is expected to experience a large number of adult returns. This is because the larger smolts survive better in the ocean, as evidenced by their overrepresentation in adult returns to freshwater for spawning (Bond et al. 2008). A large number of returning adults favors survival and recovery of the anadromous life-history form in the watershed-specific population and, more broadly, the DPS as a whole.
31 The term “harm” means any act which actually kills or injures fish or wildlife, which may include significant habitat modification or degradation that actually kills or injures fish or wildlife by significantly impairing essential behavioral patterns, including breeding, spawning, rearing, migrating, feeding or sheltering (50 CFR 222.102). This definition guides our consideration of the effects of the proposed action here (and throughout this biological opinion).
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Recall that information presented earlier in this biological opinion (section 2.4.1 Effects of the Action on Critical Habitat) indicates the proposed action would continue causing severe habitat modification or degradation in the main-stem river downstream of the dam, including the estuary. In particular, the proposed action (1) alters the pattern and magnitude of river discharge, often in combination with the interrelated activities of groundwater pumping and Upper Santa Ynez River Operations Agreement, and (2) disrupts or eliminates the natural processes that are responsible for creating and maintaining quality habitat in sufficient abundance for this species.
The effects of the action on the habitats downstream of Bradbury Dam are the basis of our consideration here, which begins with an evaluation of how the proposed action affects opportunities for survival of steelhead nests through the emergence of the young.
Survival of embryos and young steelhead in gravel nests.—Prior to the development of major water projects in the Santa Ynez River Watershed, steelhead were able to access the upper reaches and tributaries that now lie upstream of Bradbury Dam. Steelhead spawned throughout the upper reaches of the main stem and many of the joining tributaries. Under the proposed action, however, steelhead would continue to be prevented from accessing these historical habitats (Alagona et al. 2012). As a result, the listed anadromous form of O. mykiss and the creation of nests, incubation of embryos, and emergence of young would be confined to the main-stem river and small tributaries downstream of Bradbury Dam.
With regard to the tributaries downstream of the dam, our review of the proposed action indicates the physicochemical attributes of these tributaries would remain largely unaffected.
The only effect of the action involves the expected hydrologic disconnect at confluences with the main stem. In terms of the ability of the tributaries to provide freshwater spawning areas, however, no effect of the action is expected. While the tributaries are small and can experience exceedingly low flows and intermittency during the dry season, they produce young steelhead albeit in small numbers (Bureau of Reclamation 2011d, Bureau of Reclamation 2012c, Bureau of Reclamation 2013d, Bureau of Reclamation 2013e). Therefore, we expect that the proposed action would not affect survival of embryos to emergence from gravel nests in tributaries to the main stem.
With regard to the main-stem reach downstream of Bradbury Dam, spawning habitat has been noted in the Highway 154, Refugio, and Alisal reaches (SantaYnez River Adaptive Management Committee 2009). Surficial sand and smaller particle types appear to limit the quality of spawning habitat elsewhere in the main stem. However, redds constructed by steelhead appear rare in the main stem downstream of the dam, in the areas observed. If redds are constructed in the main stem, the proposed operations of Bradbury Dam increase the potential for redd scour and dewatering.
In particular, our earlier review of these effects indicate steelhead nests downstream of the dam could be susceptible to scour and desiccation owing to proposed operations of Bradbury Dam, including winter-storm operations. Whether redds would experience scour or desiccation depends partially on redd location, the magnitude of the water releases and rate of decline.
Redds in the main stem are also prone to the effects of surficial sand and smaller particles. The proposed action makes no provision for the sorts of water releases that would be capable of mobilizing the channel bed and flushing sand and smaller particles (cf. Harrison et al., in revision). Steelhead nests and incubating embryos could experience poor water quality, such as stressful or lethal dissolved-oxygen concentrations, and challenges emerging from the nests. 124
Although steelhead apparently spawn in the main-stem river and produce young (Santa Ynez River Adaptive Management Committee 2009), production is currently not a regular event.
Given the expected effects of the proposed action, and the reported site-specific characteristics and conditions, we conclude that the proposed action would continue reducing the likelihood that nests and young in the main-stem river would survive in a given year.
Growth and survival of emergent young to initial dispersal.—Our observations of the behavior and ecology of emergent steelhead indicates that when these young fish no longer associate with the nest, they typically congregate and form schools along the stream margin. This behavior can last for a few weeks before the fish disperse and establish regular positions in the stream. The period between emergence from the nest and dispersal represents another aspect of our consideration here.
At this phase, these young fish typically measure between 35 and 50 mm FL and are particularly susceptible to physical displacement during periods of elevated flows. Emergence can be observed in March; during this time, winter-storm operations can be implemented under the proposed action. However, the proposal does not appear to include an adequate operational measure for reducing the risk of displacement. The potential exists that winter-storm operations could displace young fish laterally or longitudinally downstream into areas that experience subsequent desiccation when the elevated water releases cease. Winter-storm operations conducted winter 2006 (Figure 2-33) resulted in displacement, stranding and death of twelve young steelhead (30-60 mm length) (Payne and Robinson 2007). Reclamation subsequently developed water-release ramping rates intended to prevent stranding of steelhead owing to winter-storm operations, which are incorporated in the proposed action. However, no monitoring of the effectiveness of the proposed water-release ramping rates has been conducted or proposed. Therefore the effectiveness of the ramping rates in preventing stranding would remain unknown.
Predation is another factor that could affect survival of young steelhead. The disproportionate abundance of largemouth bass in the main-stem river, relative to abundance of steelhead, prompted predatory control actions in habitats immediately downstream of Bradbury Dam (Bureau of Reclamation 2015i, Cardno 2015, Santa Ynez River Adaptive Management Committee 2009). Observations indicate that habitat conditions in the main-stem river facilitate the proliferation of predatory species (i.e., stilling basin and abundant beaver-dam pools resulting from operation of the dam). For example, on August 3, 2015, approximately 2,000 largemouth bass and 2,500 green sunfish juveniles (0-3 inches) were captured within a 30-minute period during the initial discharge of water through the stilling basin associated with water-rights releases indicating this habitat is highly productive for these non-native predatory species (Bureau of Reclamation 2016b). Elements under the proposed action provide suggested measures to control the abundance of predatory fish in the Santa Ynez River downstream of Bradbury Dam; however, the proposed measures generally lack specificity (frequency and extent of actions) and an overall commitment that they would be undertaken (i.e., dewatering the stilling basin for effective seining). Furthermore, if implemented, these actions would likely result in the incidental capture and relocation of juvenile steelhead (e.g., trapping, seining and electrofishing) and harm or death of numerous juvenile steelhead when extensive reaches of the river, inaccessible to Reclamation for undertaking capture and relocation, are dewatered for such purposes (i.e., Reclamation proposes to release only enough water, 2 cfs, to maintain flow in the first 0.75 miles downstream of the dam in about 14% of years). 125
Figure 2-33.— Comparison of the rate of inflow to Cachuma Reservoir versus the rate of water released into the Santa Ynez River downstream of Bradbury Dam for winter-storm operations during winter 2006 (source:
Shahroody and Lawler 2010). The winter-storm operations resulted in the stranding and death of five juvenile steelhead (length 30 to 50 mm, with one at 150 mm) discovered on April 7, and another seven (length 30 to 60 mm) discovered on April 11 (Payne and Robinson 2007).
Growth and survival of juvenile steelhead to the smolt stage.—We now consider the effects of the proposed action on the ability of the main-stem reach and estuary to support growth and survival of steelhead to the smolt stage. We emphasize that growth must be sufficiently rapid during summer to trigger smoltification and life in the ocean if the anadromous life-history form is to be sustained (Hayes et al. 2008). To complement our consideration, we integrated the effects of the action with findings of fishery investigations in the Santa Ynez River Basin downstream of Bradbury Dam over the last several years (Santa Ynez River Adaptive Management Committee 2009, Bureau of Reclamation 2011d, Bureau of Reclamation 2012c, Bureau of Reclamation 2013d, Bureau of Reclamation 2013e). These findings include emigranttrapping data representing Hilton Creek and Salsipuedes Creek. Surface water in Hilton Creek is largely maintained from water that is pumped from Cachuma Reservoir into Hilton Creek. This creek joins the main-stem river immediately downstream of the dam. Salsipuedes Creek is one of the largest sub-basins downstream of the dam, and enters the main stem a few miles upstream of the ocean. The tributaries typically produce lesser numbers of mostly < 170 mm FL juvenile steelhead, including smolts that immigrate to the main-stem river.
Recall that, under the proposed action, the main-stem channel would continue experiencing premature, quickened decreases in surface flow and hydrologic discontinuity. The quantity of surface flow in the main stem can fluctuate greatly over short distance, typically decreasing through percolating into the channel bed especially in braided reaches (Santa Ynez River Adaptive Management Committee 2009). These conditions are expected in a given year 126
throughout an extensive area of the main-stem river and at confluences with certain tributaries, and are typically worsened through the interrelated activity of groundwater pumping. The proposed action is designed to deliver water only to a reach extending from the dam to the Highway 154 Bridge in most years; downstream of this bridge, no or negligible surface flow can be observed. A worsening of these conditions would be observed in years when Reclamation deliberately promotes instream drying throughout the downstream river to control non-native aquatic species and beaver. In this context, and as explained in greater detail below, the proposed action is expected to continue to relegate the main stem to a poor environment for supporting growth (let alone rapid growth) and survival of juvenile steelhead, including smolts that immigrate to the main stem from tributaries.
The proposed action would continue creating or promoting certain characteristics and conditions that render the main-stem river an environment of poor growth and survival (Santa Ynez River Adaptive Management Committee 2009). This includes artificially limiting the capacity of the habitat to produce juvenile steelhead, including smolts.
For instance, the reduction or elimination of peak or flood flows due to the operations of Bradbury Dam limits the capacity of the river to produce juvenile steelhead. This conclusion is corroborated in a recent investigation of habitat changes in the lower river main stem following a flood flow (Harrison et al., in revision). The investigators found that a flow of about 27, 000 cfs caused extensive beneficial changes in river geomorphology, including lateral migration of the river channel, creation of gravel bars, deepening of pools, and establishment of off-channel chutes. The authors report that both the number and volume of pools increased downstream of the dam, and several long pools exceeding 400 ft were created. Although a variety of factors can influence abundance of juvenile steelhead in the main-stem river, the documented increase in pool number and volume generally indicates the river can produce more smolts if natural habitatforming processes would be allowed to operate; the total smolt-producing capacity of the river, as modeled in Harrison et al. (in revision), increased from about 5000 to about 16,000 fish following the flood flows. Deeper pools afford greater growth and survival habitat conditions for juvenile steelhead, particularly for juvenile fish to attain a larger size. However, the habitat downstream of the dam is poor quality as a result of the dam operations.
Indications of the poor quality habitat generally include unsuitably high water temperatures and dangerously low concentrations of dissolved oxygen, the presence of extensive algal mats in pools of the main stem that can further reduce dissolved-oxygen concentrations, desiccation throughout extensive portions of the main stem during summer, and apparently reduced types of aquatic macroinvertebrates (considered food for juvenile steelhead).
With regard to water quality in the main stem, the Santa Ynez River Adaptive Management Committee (2009) states the following:
“Water quality, particularly elevated summer water temperatures and depressed DO, have been identified as significant environmental factors affecting the habitat quality and availability for steelhead/rainbow trout both within the mainstem [sic] river and tributaries…” (pages 5-22 & 5-23).
“Exposure to seasonally elevated water temperatures and depressed DO, especially within isolated pools where algal accumulations occur during the summer months, frequently were at levels considered to be highly stressful and potentially lethal within the range resulting in acute mortality to steelhead/rainbow trout (Myrick and Cech 127
1996, 2000a, 2001). These conditions negatively affected habitat quality and availability for steelhead/rainbow trout and provide habitat opportunities for largemouth bass and other warm water fish species.” (page 5-23).
The life of juvenile steelhead in a stream can involve undertaking movements to avoid inhospitable and even lethal conditions (e.g., Smith and Li 1983, Bramblett et al. 2002). Yet the expected hydrologic discontinuity increases the likelihood that juvenile steelhead in the main stem would be unable to physically avoid poor water-quality conditions. The stressful or even lethal water quality conditions (e.g., high temperature or low dissolved oxygen) that frequently develop in the Santa Ynez River downstream of Bradbury Dam (Santa Ynez River Adaptive Management Committee 2009, Bureau of Reclamation 2013a) are not expected to favor growth and survival of juvenile steelhead.
We foresee that hydrologic discontinuity would have similar adverse effects on juvenile steelhead in the Santa Ynez River Estuary. When closed to the ocean, the estuary is particularly susceptible to fluctuations in water quality, owing to reduced natural inflow during the dry season. While juvenile steelhead are known to leave estuaries for upstream areas when waterquality problems arise (Hayes et al. 2011), the estuary is typically hydrologically isolated from upstream reaches (Santa Ynez River Adaptive Management Committee 2009). In addition, review of the “H-Street” stream gage indicates the main-stem channel upstream of the estuary is often lacking flowing water during the dry season. Predation of steelhead in the estuary may be a problem given the presence of fish-eating predators noted at that location (Kelley 2008, Santa Ynez River Adaptive Management Committee 2009). Our review of the available information indicates no or very few juvenile steelhead have been captured during seine hauls and trapping in the estuary (Santa Ynez River Adaptive Management Committee 2009).
The minimal water releases from Bradbury Dam, including from Hilton Creek, translate into reduced, simplified, and occasionally fragmented living space for juvenile steelhead (Santa Ynez River Adaptive Management Committee 2009). Because juvenile steelhead require a variety of habitats for rearing and development (Murphy et al. 1989, Johnson et al. 1994, Spina 2003), a reduction in habitat, including complexity of the habitat, adversely affects growth and survival (Harvey and Nakamoto 1997, Harvey et al. 2005, Harvey et al. 2006). Competition among juvenile steelhead for living space in the main stem is expected during summer, because juvenile steelhead are often found together (occasionally with bass) in isolated pools (Santa Ynez River Adaptive Management Committee 2009).
Juvenile steelhead in streams require consistent access to food-producing areas, in sufficient quantity, to grow and survive. The primary food-producing areas in streams are riffles, but the proposed action would continue the long-standing practice of maintaining primarily pools in the main stem, and reducing the surface area available for aquatic macroinvertebrate production.
These pools are often poor quality and isolated, with no extensive areas of broad riffles upstream (Santa Ynez River Adaptive Management Committee 2009, Bureau of Reclamation 2013a).
These habitat characteristics decrease feeding opportunities for juvenile steelhead, which can result in reduced growth (e.g., Harvey et al. 2006).
Predation is anticipated to severely crop the number of juvenile steelhead in the main-stem river.
The dominance of predatory fish species (e.g., largemouth bass) and limited availability of habitat during the dry season, resulting from the proposed action, is expected to result in high levels of predation on juvenile steelhead in the Santa Ynez River (Bureau of Reclamation 2015i). 128
Predators that are known to feed on steelhead are common in the main-stem river (Santa Ynez River Adaptive Management Committee 2009, Bureau of Reclamation 2015i) Fluctuating water releases during the summer increase the potential that juvenile steelhead would be displaced or encouraged to move downstream to reaches that are prone to dewatering. The primary source of the fluctuating water releases involves the downstream water rights under SWRCB Order WR 89-18 (referred to as “89-18 releases”) to recharge the alluvial groundwater basin upstream of the Lompoc Narrows and the Lompoc groundwater basin. These releases are typically observed between July and October. The releases can generate relatively high discharge in the river main stem over short duration that provide continuous flow to areas that are dry prior to the releases, followed by gradual declines over time and ultimately full cessation (Santa Ynez River Adaptive Management Committee 2009). However, steelhead that are displaced or relocate to downstream reaches that become dry when the water releases cease are likely to die as a result of stranding and habitat desiccation (Bureau of Reclamation 2012d).
Reclamation appears to place heavy reliance on capturing and relocating juvenile steelhead (fish rescue) when operations or unforeseen circumstances reduce or preclude water releases from Bradbury Dam to the main-stem river or Hilton Creek (Bureau of Reclamation 2015g and k) and expects such fish rescues to be conducted by other resource agencies (NMFS, CDFW, and Cachuma Operation and Maintenance Board) rather than Reclamation (Bureau of Reclamation 2015k). We agree, generally, rescuing juvenile steelhead from freshwater rearing areas that do not favor survival (loss of surface water, deteriorated water quality) is preferred to allowing them to die. However, relying on fish-rescue efforts would not compensate for the loss of freshwater rearing areas for at least a few reasons.
First, most of the main-stem river downstream of Bradbury Dam occupied by juvenile steelhead during the dry season is not accessible to Reclamation for conducting fish rescues (i.e., Reclamation’s property encompasses only about 0.75 miles of the river downstream of the dam).
Juvenile steelhead occupying these areas (e.g., between Reclamation property and Highway 154 Bridge) are expected to die when water releases from the dam cease or are reduced.
Second, the principal areas in the main-river where juvenile steelhead would be relocated are heavily populated by predatory fish (e.g., largemouth bass). Juvenile steelhead are expected to be disoriented after undergoing capture and relocation, increasing susceptibility to predation (Cardno 2015).
Survival of smolts, and size at ocean entry.—As described below, the effects of the proposed action impair essential behavioral patterns of juvenile steelhead, thereby decreasing the prospects of smolt survival and large size at ocean entry.
Studies of juvenile steelhead in California coastal streams have frequently shown that fish experiencing the growth benefits of estuaries, in contrast to fish rearing in upstream reaches, can achieve a size at ocean entry that favors marine survival (e.g., Bond et al. 2008, Hayes et al. 2008). But the proposed action is expected to create infrequent opportunities, of shorter duration, for smolts to access the estuary (see section 2.4.1.1 Effects on Critical Habitat doe to Operating Bradbury Dam). Even if juvenile steelhead reach the estuary, the documented waterquality conditions and presence of predators (Kelley 2008, Santa Ynez River Adaptive Management Committee 2009), reduce the chance that this life stage would survive in the estuary, let alone experience increased (rapid) growth opportunities. 129
Although Hilton Creek and Salsipuedes Creek are known to produce smolts, these downstream migrants (Bureau of Reclamation 2011d, Bureau of Reclamation 2012c, Bureau of Reclamation 2013d, Bureau of Reclamation 2013e) are typically not the larger smolts (≥ 200 mm FL) that make up a disproportionately larger part of adult returns to freshwater for spawning (Bond et al. 2008). Rather, smolts leaving the tributaries are often < 170 m FL (Santa Ynez River Adaptive Management Committee 2009). In addition, juveniles that rear entirely in tributaries are not expected to consistently reach a size where return as adult is probable; investigators report that about 87% of returning adults have experienced the growth benefits of rearing in estuaries, not upstream (Hayes et al. 2011).
Prior to the development of major water projects in the Santa Ynez River Watershed, the mainstem river, including the reach now downstream of Bradbury Dam, was probably capable of producing smolts of a size that survived and matured in the ocean (Alagona et al. 2012). Even today in watersheds lacking major water projects, main-stem reaches are known to support multiyear freshwater rearing and attainment of sizes that are consistent with the marine-survival criterion (Spina et al. 2005). In addition, while anthropogenic activities during at least the last century have profoundly altered the ability of main stems to support multiyear freshwater rearing, evidence indicates such areas were once perennial and cool (Boughton et al. 2006, O’ Dowd et al. 2014). As we reviewed earlier, the proposed action would continue worsening the ability of the main stem downstream of the dam to support growth and survival of juvenile steelhead. Therefore, we don’t anticipate the main stem would produce many smolts of the appropriate size for surviving the ocean.
We now shift our focus from how the proposed action influences smolt size to effects on the ability of smolts to access the ocean.
The proposed action creates and promotes conditions that would preclude many smolts from reaching the ocean. For instance, most of the larger smolts are emigrating to the main stem in the middle and end of the migration season (Bureau of Reclamation 2011d, Bureau of Reclamation 2012c, Bureau of Reclamation 2013d, Bureau of Reclamation 2013e). During this same period, surface-flow conditions in the river main stem are rapidly deteriorating or nonexistent (Kelley 2008, O’Dowd et al. 2014) and individual emigrants appear to be experiencing hydrologic discontinuity and poor migratory conditions in most years (cf. Figure 2-22). The reduced number of smolts caught at downstream sites in the main stem relative to the number initially caught at the upstream sites (Table 2-12) reflects that the conditions in the main stem pose a significant problem for smolts attempting to enter the ocean.
Although smolts occasionally enter the ocean during periods of naturally elevated river discharge in the watershed (e.g., when discharge in Salsipuedes Creek is high), the chance for ocean entry and the number of smolts that ultimately enter the ocean (Bond et al. 2008, Hayes et al. 2008) is expected to be reduced due to the proposed action. The principal mechanism for this effect involves the reduced frequency, duration and magnitude of in Santa Ynez River discharge downstream of Bradbury Dam that consequently is expected to reduce the frequency and duration the estuary is connected with the ocean. This means that fewer fish will be able to access the ocean because entry is only available during the artificially abbreviated periods of ocean-estuary connectivity (Santa Ynez River Adaptive Management Committee 2009).
Because the sandbar closes earlier under the proposed action, more fish are expected to collect in the estuary. These fish are likely to experience harm or even death during the summer owing to poor water-quality conditions and predators, with no available escape corridor upstream. 130
Although producing a large number of sizable smolts is critically important for the survival of the anadromous form of O. mykiss, the foregoing evaluation indicates the proposed action would continue significantly impairing the ability of the habitat in the main-stem river and estuary to function consistent with the life history and habitat requirements of steelhead. As we described above, the proposed action is expected to continue to decrease prospects that most juvenile steelhead in the watershed would grow and survive to the smolt stage, reach large size at ocean entry, and have access to the ocean. The existing habitat characteristics and condition of the lower main-stem river downstream of Bradbury Dam, which are expected to continue as a result of the proposed action, in combination with tributaries in this river segment, are incapable to produce the number of fish necessary for the watershed-specific population of steelhead that would contribute to recovery of the DPS (National Marine Fisheries Service 2012c). This expectation was corroborated by two independent steelhead ecologists, Dr. William Trush and Dr. Charles Hansen, during testimony before the California State Water Resources Control Board for the Cachuma Project water rights hearing on March 29 and 30, 2012 (SWRCB 2012a and b).
2.4.3.2 Effects due to Maintenance Activities at Bradbury Dam Maintenance activities that reduce or eliminate flow in Hilton Creek or the Santa Ynez River can increase the risk of harm or death to steelhead. These activities are described below.
Dewatering portions of the Santa Ynez River to conduct maintenance of the Bradbury Dam stilling basin or USGS gaging stations could cause steelhead to become stranded in dewatered habitats, ultimately causing harm or death. However, the risk of stranding, and therefore harm and death, would be reduced because prior to conducting such maintenance, Reclamation proposes to capture and relocate any steelhead that may be present to reduce this risk.
Annual exercising of the Hilton Creek Water System outlet valves are expected to temporarily (<4 minutes) halt water releases to Hilton Creek. Disrupting water releases to Hilton Creek, even briefly, can dewater shallow habitats along the stream margin and backwater areas.
Juvenile steelhead, particularly early life-history stages, stranded in dewatered areas would be harmed or killed.
Testing and maintaining the Hilton Creek Water System pumps are expected to temporarily reduce or eliminate flow in Hilton Creek. Reducing or eliminating flow in Hilton Creek results in steelhead becoming stranded in dewatered habitats causing harm or death (Bureau of Reclamation 2013b). Although Reclamation (2015c) indicates they are developing methods to test the Hilton Creek Water System pumps in a manner that does not interrupt flow in Hilton Creek, such as the March 1, 2013, incident that killed at least 53 juvenile steelhead, Reclamation has not provided us with a completed plan that would do so.
In addition to the effects resulting from proposed maintenance of the Hilton Creek Water System, the apparent lack of maintenance and delay in repairing or modifying the Hilton Creek Water System has resulted in harm or death of endangered steelhead (Table 2-13) (Bureau of Reclamation 2013a, b, c, Bureau of Reclamation 2014c). Reclamation subsequently repaired and replaced faulty pumps, upgraded the electrical system, and installed an emergency backup system to avoid or reduce interruptions of the Hilton Creek water system. However, a recent effort by Reclamation to use the emergency backup system pumps to supply water to Hilton Creek failed; the failure to start the water pumps was diagnosed as uncharged batteries supporting the diesel-powered generators (Bureau of Reclamation 2016a). Therefore, this risk of 131
harm or death of steelhead resulting from failure of the Hilton Creek Water System to reliably maintain flow in Hilton Creek is expected to continue because measures to address such failures have not yet been proven effective.
Table 2-13—Hilton Creek Water System failures that resulted in the capture, harm and death of steelhead/rainbow trout (Oncorhynchus mykiss) (Bureau of Reclamation 2013b, 2013c and 2014, Robinson 2014). The totals presented represent the number of individuals observed and likely underrepresents the actual number of O. mykiss harmed or killed. For example, prior to the incident of March 1, 2013, 1,073 O. mykiss were observed (snorkel survey) in Hilton Creek in October 2012; immediately following the incident only 56 O. mykiss were observed in Hilton Creek.
Incident date Total number of O. mykiss killed Total number of O. mykiss stranded, captured and relocated
March 1, 2013 56 25
June 23, 2013 87 1
March 1, 2014 14 4
March 11, 2014 8 56
March 26, 2014 1 1
May 25, 2014 217 543
2.4.3.3 Proposed Monitoring Program for Endangered Steelhead and Habitat Conditions Reclamation’s proposed monitoring program is expected to adversely affect steelhead due to capturing and handling individual specimens. In addition, Reclamation’s proposed monitoring program is not expected to be effective as a means to minimize the effects of the proposed action on this species as proposed by Reclamation.
Continue to capture and handle endangered steelhead
Reclamation proposes to continue, and expand upon, the capture and handling of migrating steelhead, resulting in take of this species. Recent monitoring conducted or directed by Reclamation in the Santa Ynez River resulted in the capture of 16 adult and about 600 juvenile steelhead in a single year (Cachuma Operations and Maintenance Board 2013). Although Reclamation’s current program only operates migrant traps at one location in the main-stem river and one location each in Hilton and Salsipuedes creeks, under the proposed action Reclamation suggests that additional trap locations may be established in the main-stem river, the existing two identified tributaries and additional tributaries (Bureau of Reclamation 2015h). Therefore, all adult and most juvenile steelhead migrating through the Santa Ynez River and tributaries downstream of Bradbury Dam in a given year could conceivably be captured, resulting in increased risk of harm due to migration delay and handling-related stress. For example, in a year that 1,500 or more juvenile steelhead are predicted to reside in Hilton Creek, Reclamation estimates that a total of 1,082 steelhead may be captured, handled and released and an additional 109 steelhead may be killed (Bureau of Reclamation 2015g). Reclamation does not specify the 132
life stage (adult or juvenile) in their estimate of the number of steelhead that may be captured or killed due to the proposed monitoring program.
However, after carefully considering Reclamation’s proposed plan to adaptively manage incidental take of steelhead, we find the plan creates the potential for excessively high levels of incidental take with no meaningful way of guarding against undue take for any one particular life stage. For instance, the proposed plan does not stipulate numerical take limits for juvenile or adult life stages; such limits are biologically necessary to protect each life stage from unreasonably high take levels. We recognize that the proposed plan was crafted, in part, to provide much needed flexibility to account for the possibility of inter-annual fluctuations in steelhead abundance and, therefore, concordant changes in the number of steelhead that would be affected by monitoring activities (e.g., high abundance of steelhead is expected to prompt high rates of encounter). However, the proposed plan does not provide a meaningful mechanism for ensuring the actual take levels observed in the field would be minimized, particularly for specific life stages.
Effectiveness of the monitoring program to minimize adverse effects on endangered steelhead
As we described in section 2.4.1.3, the stated objective of the monitoring plan is “to develop technical information and data on the Lower Santa Ynez River Southern California steelhead population and its habitat for use in management that supports operation of the Cachuma Project (Project) to meet its purpose while minimizing adverse effects to the Southern California steelhead.” (p. 2, Bureau of Reclamation 2015h). When considering the effects of the proposed action on designated critical habitat, we evaluated the capability of Reclamation’s proposed monitoring program (Bureau of Reclamation 2015h) to detect and reconcile adverse effects. Our evaluation concludes that the proposed monitoring plan lacks the necessary framework to (1) reliably assess, let alone detect, effects that are attributable to the proposed action, (2) inform the development and implementation of changes to the Project operations for the purpose of minimizing effects due to the proposed action, and (3) evaluate whether the changes in operations have minimized effects on endangered steelhead. We therefore do not expect the monitoring plan would be effective, as currently designed, for minimizing effects on endangered steelhead. For the bases of this conclusion, see section 2.4.1.3 of this biological opinion.
2.4.3.4 Effects due to Operating and Maintaining the Tecolote Tunnel-South Coast Conduit In this section we present the effects of the proposed action on endangered steelhead resulting from inspection, maintenance and operation of the South Coast Conduit and associated regulating reservoirs. Before presenting the effects of the existence and maintenance of this conduit, we note that the effects resulting from operation of Glen Annie Dam and Reservoir previously described under effects on critical habitat are not transferred to effects on steelhead.
This is because human-caused impassable barriers to steelhead migration are located about three miles downstream of Glen Annie Dam (Bureau of Reclamation 2013a, Stoecker 2002) and are expected to prevent adult steelhead from accessing and populating this portion of the watershed.
Should these migration barriers be remediated and provide steelhead access to Glen Annie and West Fork Glen Annie Creeks, we expect the proposed operations of the dam and reservoir will cause harm to all life stages of endangered steelhead by impairing essential behavioral patterns (e.g., migration, spawning and rearing). Although we are not aware of any specific proposal or schedule for remediating these steelhead migration barriers, it is likely that these migration 133
barriers will be addressed in the future because many similar types of migration barriers (e.g., road crossings) have already been remediated in nearby streams and many more are being planned for remediation (Bureau of Reclamation 2011a).
Inspection and maintenance of the South Coast Conduit and Carpinteria Reservoir under the proposed action results in periodic discharges of water disinfected with chlorine to numerous streams inhabited by juvenile steelhead (i.e., Mission Creek, Sycamore Creek, Montecito Creek, San Ysidro Creek, Romero Creek, Arroyo Paredon Creek, and Carpinteria Creek). Although the treated-water is purported to undergo de-chlorination prior to discharge, the biological assessment (Bureau of Reclamation 2013a) does not provide sufficient detail to determine the effectiveness of de-chlorinating water prior to release (i.e., amount of residual chlorine in discharged water). Because even low concentrations of chlorine can cause sub-lethal or lethal effects to juvenile steelhead (Cooke and Scheerer 2001), we expect the potential exists that one or more juvenile steelhead could be harmed or perhaps killed when exposed to these treatedwater discharges resulting from the proposed action. At this time we don’t have specific information that allows us to adequately predict the potential number of juveniles that could be affected.
Maintenance and operation of the South Coast Conduit under the proposed action is expected to perpetuate reduced migration opportunities for adult and juvenile steelhead, significantly impairing essential behavioral patterns (e.g., migration, rearing and sheltering). Locations where the South Coast Conduit pipeline is exposed in various streams (Table 2-10), or may become exposed in the future, are expected to impede or prevent (1) migration of adult steelhead seeking suitable spawning areas, and (2) movement of juvenile steelhead seeking available rearing areas to the extent described in Table 2-10. Inhibiting upstream migration of adult steelhead may cause selection of poor quality spawning areas resulting in reproduction failure. Preventing movement (i.e., redistribution) of juvenile steelhead, particularly during the dry season, reduces the ability of juveniles to escape increasing intraspecific competition for space and food, or areas of reduced water quality or quantity (drying conditions). Obstructions in freshwater migration corridors for this species as a result of the proposed action is expected to reduce the number of locations this species can access (i.e., population spatial structure) and prevent individuals from fully expressing life history traits, such as upstream migration to historical spawning and rearing habitats (i.e., population diversity).
2.4.4 Consequences for Steelhead Survival and Recovery in the Action Area In this section we evaluate the combined influence of the effects of the action (Bradbury Dam and South-Coast Conduit) and the interrelated actions on the survival and recovery of endangered steelhead in the action area. The information we provide here informs our understanding of the implications of the proposed action for survival and recovery of the endangered Southern California DPS of steelhead, which is described in Section 2.6 of this biological opinion.
Summary of the Effects of the Proposed Action
As we described in above in section 2.4, the effects of the proposed action are projected to include significant impairment of the habitat in the action area to function in accord with the life history and habitat requirements of endangered steelhead. The direct and indirect effects of the proposed action would continue suppressing population abundance, population growth rate, population spatial structure, and population diversity of Southern California DPS steelhead 134
throughout the action area. Suppression of population abundance, population growth rate, population spatial structure, and population diversity of Southern California steelhead is expected as a consequence of the proposed action disrupting or precluding steelhead in the action area from completing essential elements of their life-history pathway by (a) altering the quality and availability of the freshwater migration corridor essential for adult steelhead migrating upstream from the ocean to freshwater spawning and rearing sites and smolts migrating downstream to the estuary and ocean downstream of Bradbury Dam, (b) altering the quality and availability of freshwater spawning and rearing sites in the river downstream of Bradbury Dam, and (c) continuing to prevent adult steelhead from migrating to more abundant, higher quality spawning and rearing habitats upstream of Bradbury Dam and their progeny (e.g., smolts) from migrating downstream past the dam to the estuary and ocean.
Summary of the Effects of the Interrelated Actions
The interrelated actions of groundwater pumping and the Upper Santa Ynez River Operations Agreement are expected to worsen the effects of the proposed action on endangered steelhead in the Santa Ynez River Watershed downstream of Bradbury Dam. The effects of these interrelated actions are expected to exacerbate the reduced amount and extent of surface flow in the mainstem reach and reduce the amount of water flowing downstream during naturally elevated periods of river discharge.
The effects of the interrelated action of stocking hatchery O. mykiss in Cachuma Reservoir and the Central Coast Water Authority state water project deliveries and releases are expected to be avoided by measures that are currently in place and are expected to continue. Stocking only sterilized trout in Cachuma Reservoir, as required by CDFW, would avoid the risk of genetic introgression with the native steelhead. The interrelated action of releases of the Central Coast Water Authority state water project water into the Santa Ynez River is unlikely to disrupt olfactory imprinting of juvenile steelhead owing to current and proposed restrictions on the timing and rate this water is discharged into the river.
Implications for Steelhead Survival and Recovery in the Action Area The effects of the proposed action are expected to result in conditions that select against expression of the anadromous form of O. mykiss. These effects and conditions, which are described above in this biological opinion, include (1) decreasing migration opportunities for adult and juvenile steelhead downstream of Bradbury Dam, (2) causing the main-stem river and estuary downstream of Bradbury Dam to capture and collect steelhead, especially juveniles, leaving individuals with no access to the ocean or upstream perennial reaches, (3) unnaturally confining steelhead downstream of Bradbury Dam, which confines individuals to less suitable habitat characteristics and conditions, (4) reducing interchange between the resident and anadromous form of O. mykiss, (5) disrupting or eliminating the natural processes that are responsible for forming and preserving physical or biological features of critical habitat designated for the Southern California steelhead DPS , and (6) creating and maintaining obstructions in the freshwater migration corridor for steelhead in streams crossed by the SouthCoast Conduit, which either confine individuals to less suitable habitat characteristics and conditions downstream of the crossings, or delay individuals from reaching upstream spawning and rearing habitats. Adult steelhead are currently rare in the Santa Ynez River Watershed, and because the effects of the proposed action are expected to result in conditions that select against expression of the anadromous life-history form in this watershed and several of the smaller 135
coastal-basins where the South-Coast Conduit crosses (i.e., impeding or precluding migration, Table 2-10), the proposed action is expected to reduce prospects for steelhead viability in the action area.
We know the Project operations are adversely affecting endangered steelhead in the action area because the effects are clearly visible, and these operations and effects are expected to continue under the proposed action. For example, the extensive monitoring data collected over many years in the lower main-stem river downstream of Bradbury Dam indicate few sizable steelhead smolts typically enter the ocean each year and even fewer adult steelhead are annually returning to the river for spawning (Santa Ynez River Adaptive Management Committee 2009). This is of concern because a large number of sizeable smolts must routinely enter the ocean each year in order for a large number of adult steelhead to return annually to the watershed (Ward et al. 1989, Bond et al. 2008); a substantial number of returning adults is critical to ensure the long-term survival and recovery of this species in the Santa Ynez River Watershed and, more broadly, the Southern California DPS of steelhead (NMFS 2012).
While a number of threats adversely affect steelhead and its habitat in the action area, the available information corroborates that Reclamation’s Project operations create and maintain much of the existing poor habitat characteristics and conditions, and occasionally cause mortality of endangered steelhead. These operations and effects are expected to continue under the proposed action. Operations of Bradbury Dam, for example, affect the volitional movement of juvenile steelhead, particularly when movement is most important to sustain growth and survival of this specific life stage. Juvenile steelhead must be allowed to volitionally migrate between and among habitats to survive, grow, and reach large size at ocean entry. This includes the ability to migrate between the river main stem and the tributaries, particularly in response to changing environmental conditions. However, the Project operations preclude or substantially reduce the opportunity for this movement.
Although Reclamation and its cooperators have undertaken more than a decade of habitat improvements in the watershed downstream of Bradbury Dam (Santa Ynez River Adaptive Management Committee 2009), and instituted supplemental water releases to benefit steelhead (Bureau of Reclamation 2013a), these efforts have clearly failed to address the key needs of the species. The proposed action continues to propose the same flow-management strategy that is in large part responsible for the adverse effects that are visible today. This strategy results in tributary inflow from the lower watershed primarily providing flows in the mainstem Santa Ynez River to create and maintain physical or biological features of critical habitat designated for the Southern California steelhead DPS, consequently diminishing the value of the freshwater migration corridor, freshwater spawning sites and freshwater rearing sites in the river main stem (see Table 2-1). As we described above in this “Effects of the Action” section of the biological opinion, while Reclamation defines supplemental water releases from Bradbury Dam for the intended purpose of conserving steelhead, decision criteria, or “triggers,” are specified for the releases; eight triggers are specified for the passage-supplementation water releases alone.
Unfortunately, the triggers are defined in a manner that greatly reduces the likelihood, frequency, and duration of water releases from Bradbury Dam and have the functional effect of abetting the adverse effects of the proposed action. Overall, the effects of Reclamation’s proposed action are expected to create and maintain conditions that select against the survival and recovery of the anadromous life history form of O. mykiss in the action area. 136
2.5 Cumulative Effects
“Cumulative effects” are those effects of future state or private activities, not involving federal activities, that are reasonably certain to occur within the action area of the federal action subject to consultation (50 CFR 402.02). Future federal actions that are unrelated to the proposed action are not considered in this section because they require separate consultation pursuant to Section 7 of the ESA.
Future state, local, or private actions that are reasonably certain to occur within the action area are related to agricultural activities and urbanization. These are generally ongoing actions that will continue into the future, and the current effects of these actions described in section 2.3 (Environmental Baseline) of this biological opinion are generally expected to continue into the future. While some of these actions may be physically located outside the action area, they are expected to create effects that extend into the action area and are therefore considered here.
Agricultural Activities
Agriculture, principally involving cattle grazing and cropland, are reported for the action area (Bureau of Reclamation 2013a) and, when undertaken in a manner that damages steelhead habitat, can represent a threat to the survival and recovery of endangered steelhead (National Marine Fisheries Service 2012c). Within the broad action area, agriculture is primarily confined to the Santa Ynez River portion; cropland is limited to the river floodplain, whereas cattle grazing is widespread within the mainstem Santa Ynez River and tributaries (e.g., Salsipuedes Creek). The potential effects of these activities include a reduction in the availability and quality of habitat for endangered steelhead owing to increased input of sand and smaller particles to waterways, loss or reduction in the amount of streamside vegetation, and input of harmful chemicals.
Urbanization
Urbanization and population growth are expected to increase the potential for adverse effects to steelhead. Increasing the amount of impervious surfaces within the action area watersheds is expected to increase the potential for dry and wet-season runoff and input of potentially toxic elements to surface water where steelhead are present. Continued urbanization is expected to cause elevated rates of treated-wastewater releases to streams, possibly increasing nitrogen loads and the likelihood of adverse effects on aquatic organisms. Housing developments constructed in or near the historical floodplains of the Santa Barbara County creeks and rivers are expected to cause, or perpetuate, loss of aquatic habitat. Riparian vegetation removal is expected to reduce stream shading and overhead cover, increase water temperatures, and minimize the contribution of woody debris to streams habitats. The effects to steelhead resulting from flood-control maintenance activities include a reduction in the quality and quantity of rearing and spawning habitat.
Wastewater treatment and discharge into the Santa Ynez River watershed occurs from two treatment facilities. The City of Lompoc facility discharges up to five million gallons per day into San Miguelito Creek; the Santa Ynez Band of the Chumash Indians facility discharges up to 200,000 gallons per day into Zanja de Cota Creek. Treated wastewater that is returned to streams has the potential to increase streamflow and living area for aquatic species, including steelhead. However, other effects of releasing wastewater into streams are the potential to increase water temperature and nutrient load. Introduction of wastewater that is warmer than the 137
ambient stream temperature can degrade spawning and rearing habitat. Increased nutrient loading has the potential to promote growth of filamentous algae and cause diurnal fluctuations in water quality (e.g., dissolved oxygen). Research has demonstrated that inputs from wastewater treatment plants to streams can contribute substantially to changes in water quality, potentially affecting downstream ecosystems (Figueroa-Nieves et al. 2014).
2.6 Integration and Synthesis
This section represents the final step in our assessment of the risk posed to the endangered Southern California DPS of steelhead and designated critical habitat for this species as a result of implementing the proposed action. Here, we add the effects of the action (Section 2.4) to the environmental baseline (Section 2.3) and the cumulative effects (Section 2.5), taking into account the status of the species and critical habitat (Section 2.2), to formulate our biological opinion on whether the proposed action is likely to: (1) reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing its numbers, reproduction, or distribution; or (2) reduce the value of designated critical habitat for the conservation of the species.
Summary of the Status of the Species and Environmental Baseline Anthropogenic activities have severely depressed the abundance, population growth rate, population spatial structure, and population diversity of steelhead in the action area and in the Southern California DPS. Currently, the Southern California DPS of steelhead is at a high risk of becoming extinct in the foreseeable future (i.e., the likelihood of viability is low).
The past and current effects of major-water projects in the Santa Ynez River Watershed result in conditions that select against the sustainment of the anadromous form of O. mykiss in this watershed. Adult steelhead remain scarce in the watershed, despite the past decade of restoration efforts by the local water agencies. The principal mechanisms for this impact involve (1) the ongoing capture and storage of surface water, which reduce the pattern and magnitude of river discharge downstream of Bradbury Dam, (2) groundwater pumping, which decreases and occasionally eliminates the amount and extent of surface water in the main stem during the dry season and extended rain-free periods during the wet season, (3) introduction of obstructions in the freshwater migration corridor, which cause habitat fragmentation, and preclude steelhead from accessing historical spawning and rearing habitats and interchange of the resident and anadromous form, and (4) precluding the natural processes that create and maintain physical and biological features for the conservation of endangered steelhead (i.e., freshwater migration corridor, freshwater spawning sites, and freshwater rearing sites). The construction and subsequent operation of Gibraltar Dam and Reservoir contributed measurably to loss of historic migration opportunities for steelhead in the watershed, including the action area (O’Dowd et al. 2014). These impacts constitute the principal threats contributing to the high extinction risk of steelhead in the Santa Ynez River portion of the action area and DPS as a whole (National Marine Fisheries Service 2012c).
Past and ongoing agricultural uses, gravel mining and flood management, when undertaken in a manner that damages stream and riparian areas, reduce the availability and quality of habitat for steelhead owing to alteration of stream and river channels, increased input of sand and smaller particles to streams and rivers, and loss or reduction in the amount of riparian vegetation. Our review of the past and ongoing effects of anthropogenic activities in the action area also identified the South Coast Conduit as a threat to endangered steelhead and the value of 138
designated critical habitat for the conservation of the species. The physical presence of the conduit in streams impedes or prevents the ability of steelhead to access habitats upstream of the conduit. The operation of Glen Annie Dam continues to reduce or preclude streamflow in Glen Annie Creek that is essential for establishing and maintaining suitable habitat for steelhead.
Summary of the Aggregate Effects
The aggregate effects involve collective consideration of the effects of the action, environmental baseline, and the cumulative effects, taking into account the status of the species and critical habitat.
In section 2.4.4 of this biological opinion we conclude the effects of the action and interrelated activities would reduce the prospects for the viability of endangered steelhead in the action area by (1) decreasing migration opportunities for adult and juvenile steelhead downstream of Bradbury Dam, (2) causing the main-stem river and estuary downstream of Bradbury Dam to capture and collect steelhead, especially juveniles, (3) unnaturally confining steelhead downstream of Bradbury Dam, which confines individuals to less suitable habitat characteristics and conditions, (4) reducing interchange between the resident and anadromous form of O. mykiss, (5) disrupting or eliminating the natural processes that are responsible for forming and preserving physical or biological features of critical habitat designated for the Southern California steelhead DPS, and (6) creating and maintaining obstructions in the freshwater migration corridor for steelhead in streams crossed by the South-Coast Conduit, which either confine individuals to less suitable habitat characteristics and conditions downstream of the crossings, or delay individuals from reaching upstream spawning and rearing habitats. Our review of the historical and forecasted effects of climate changes (section 2.2.4), and cumulative effects, indicate these would worsen the effects of the proposed action and interrelated activities.
Chiefly, climate change is expected to further reduce the availability and quality of living space for endangered steelhead, including the ability to pursue life-history pathways that are essential to sustain the anadromous form.
With regard to critical habitat, the effects of the proposed action are expected to continue to appreciably reduce or eliminate the value of freshwater migration corridor, rearing sites, and spawning areas in the Santa Ynez River Watershed for the conservation of endangered steelhead.
The proposed action is expected to continue to reduce the function of the migration corridor in Glen Annie Creek due to operation of Glen Annie Dam, and in several other coastal streams at the South Coast Conduit intersections.
Consequences of the Aggregate Effects
The aggregate effects of the action, environmental baseline, and the cumulative effects, taking into account the status of the species and critical habitat, are expected to (a) reduce appreciably the likelihood of both survival and recovery of the Southern California DPS of steelhead in the wild by reducing its numbers, reproduction, or distribution, and (b) appreciably diminish the value of critical habitat for both the survival and recovery of this species.
As a matter of background, the larger river systems in southern California have been the historical foundation for the endangered Southern California DPS of steelhead (Boughton et al. 2007). The Santa Ynez River watershed is one such system because of the watershed’s large size, spawning and rearing habitat quality, relatively reliable winter river discharge, and greater potential for being independently viable (Boughton et al. 2006). However, the abundance of 139
steelhead in the Santa Ynez River, like other drainages throughout the DPS, has been dramatically reduced due to a variety of anthropogenic alterations to the watershed and waterways (National Marine Fisheries Service 2012c). Presently, the number of steelhead in the Santa Ynez River watershed is very small and adult returns to the watershed are sporadic.
Likewise, the number of steelhead comprising the DPS is small. Because the viability of small populations is especially tenuous, and such populations are susceptible to prompt decreases in abundance and possess a greater risk of extinction relative to large populations (Pimm et al. 1988, Berger 1990, Primack 2004), activities that reduce the quality and quantity of habitats, or that preclude formation of population units, are expected to compel the species toward extinction as individual population units become extinct (McElhany et al. 2000).
The effects of the proposed action, when added to the environmental baseline, are sufficient to appreciably reduce the likelihood of viability for the Santa Ynez River population unit of steelhead and, more broadly, the endangered Southern California DPS of steelhead (i.e., appreciably reduce the likelihood of both survival and recovery of the species). The Southern California Steelhead Recovery Plan (National Marine Fisheries Service 2012c) considers the Santa Ynez River population unit essential to the survival and recovery of the Southern California DPS of steelhead and identifies actions necessary for this population unit to achieve viability. These actions include (1) implementing operating criteria to ensure the pattern and magnitude of groundwater extractions and water releases from Bradbury Dam provide essential habitat functions to support the life history and habitat requirements of adult and juvenile steelhead, and (2) physically modifying Bradbury Dam to allow steelhead natural rates of migration to upstream spawning and rearing habitats, and passage of smolts and kelts downstream to the estuary and ocean. As described above in the effects analysis, the proposed action appreciably reduces or precludes development and maintenance of physical or biological features of critical habitat designated for the Southern California steelhead DPS in the Santa Ynez River downstream of Bradbury Dam. And, the proposed action provides no means for allowing steelhead migration (upstream and downstream) past Bradbury Dam, which will continue to subject steelhead to adverse effects of the action downstream of Bradbury Dam.
Given the value of the Santa Ynez River population unit of steelhead to the viability of the broader DPS and its relationship to recovery (National Marine Fisheries Service 2012c), the effects of the proposed action are expected to continue reducing the likelihood of both species survival and recovery. The Santa Ynez River steelhead population unit is one of only a few population units in the endangered Southern California DPS of steelhead that show a high potential of being independent and able to withstand environmental stochasticity once restored to viability. The effects of environmental fluctuations and disturbances (e.g., floods, increased air temperature, wildfire, and drought) and demographic accidents (e.g., varying or unpredictable birth and death rates, sex-ratio fluctuations that have significant effects for species with low abundance) create an added risk of DPS extinction to that arising from the aggregate effects alone. The Santa Ynez River steelhead population is expected to support formation of steelhead numbers in adjacent population units that may not otherwise exist if not for the core population.
The formation and maintenance of population units effectively increases numbers of individuals in the broad population, and given the risk of extinction that small populations face (e.g., Pimm et al. 1988, Primack 2004), a larger number of individuals decrease the risk of weakened viability of the DPS. Consequently, this population is expected to contribute to the viability of the endangered Southern California DPS of steelhead and recovery of the species (Boughton et al. 2006, National Marine Fisheries Service 2012c). However, because the proposed action is 140
expected to continue reducing the viability of the Santa Ynez River steelhead population unit, and its ability to withstand environmental stochasticity, the abundance of steelhead in adjacent population units (i.e., those that depend on abundance of steelhead in, or immigrants from, the Santa Ynez River) is expected to be reduced as well.
With regard to climate change, information indicates that precipitation in southern California will exhibit measurable decreases in the future (Hayhoe et al. 2004), which will exacerbate the effects of the proposed action, especially the effects of water diversion and storage activities during below normal and normal water years.
With regard to designated critical habitat, the value for the conservation of the species of freshwater migration corridors, freshwater spawning sites, and freshwater rearing sites within the action area would continue to be reduced or eliminated due to the aggregate effects. The effects of the proposed action, when added to the environmental baseline, preclude or significantly delay development these physical or biological features of critical habitat designated for the Southern California steelhead DPS. This loss or delay in development of the physical or biological features of steelhead critical habitat in the action area appreciably reduces the value of critical habitat for the conservation of the endangered Southern California steelhead DPS. We reach this conclusion because of the magnitude and duration of impacts to critical habitat in the action area described in the “Summary of Aggregate Effects” above and the importance of this watershed to the conservation of the species.
2.7 Conclusion
After reviewing and analyzing the current status of the Southern California steelhead DPS and critical habitat for this species, the environmental baseline within the action area, the effects of the proposed action, any effects of interrelated and interdependent activities, and cumulative effects, it is NMFS’ biological opinion that the proposed action is likely to jeopardize the continued existence of the Southern California steelhead DPS and destroy or adversely modify its designated critical habitat.
2.8 Reasonable and Prudent Alternative
“Reasonable and prudent alternatives” refer to alternative actions identified during formal consultation that can be implemented in a manner consistent with the intended purpose of the action, that can be implemented consistent with the scope of the federal agency’s legal authority and jurisdiction, that are economically and technologically feasible, and that would avoid the likelihood of jeopardizing the continued existence of listed species or resulting in the destruction or adverse modification of critical habitat (50 CFR 402.02).
We believe the following Reasonable and Prudent Alternative (RPA) is necessary and appropriate to avoid the likelihood of jeopardizing the continued existence of the Southern California steelhead DPS and resulting in the destruction or adverse modification of critical habitat designated for this species:
Reclamation shall operate and maintain the Cachuma Project in a manner that facilitates development and maintenance of physical or biological features of critical habitat designated for the Southern California steelhead DPS and provides passage of adult and juvenile steelhead at or around Bradbury Dam. To this end, the RPA involves eight elements, all of which must be fully implemented to avoid the likelihood of jeopardizing the continued existence of the Southern California steelhead DPS and resulting in the destruction or adverse modification of critical 141
habitat designated for this species. Because this biological opinion determined the proposed action is likely to jeopardize the continued existence of the Southern California steelhead DPS and destroy or adversely modify its designated critical habitat, Reclamation is required to notify us of its final decision on implementation of the RPA (50 CFR §402.15(b)). The elements of the RPA are as follows:
1) Steelhead migration, spawning and rearing flows—As described in the effects analyses in the biological opinion, the proposed operation of Bradbury Dam would continue to reduce, and at times eliminate, opportunities for steelhead to migrate, spawn and rear in the mainstem and estuary of the Santa Ynez River. Therefore, Reclamation shall implement water releases from Bradbury Dam in accordance with Table 2-13 to establish and maintain physical or biological features of critical habitat designated for the Southern California steelhead DPS, as described below in this element.
To assist Reclamation in ensuring the proposed action is not likely to jeopardize the continued existence of the Southern California steelhead DPS or result in the destruction or adverse modification of critical habitat designated for this species, we emphasize that the water-release schedule defined in Table 2-13 and described in more detail below is the recommended minimum release of water from Bradbury Dam. Development of the waterrelease schedule was informed by analyses of the Santa Ynez River Watershed presented earlier in this biological opinion. The water-release schedule may be revised based on new information obtained through implementing other elements of the RPA, such as the implementation and monitoring plan (element 5).
River-estuary-ocean connectivity and adult migration, spawning and incubation waterreleases apply a minimum release of 150 cfs from Bradbury Dam for attaining certain flowbased objectives. This water-release rate represents the median pre-dam high flow pulse, 32 is
consistent with the existing release capacity of the dam outlet works, and is expected to provide flow continuity throughout the Santa Ynez River downstream of Bradbury Dam, including compensation for surface-flow loss through percolation. Water-release initiation and cessation triggers correspond to natural river discharge-pulses produced from the watershed upstream of Bradbury Dam that would otherwise have flowed to the estuary and ocean, and are intended to synchronize with naturally elevated tributary streamflow downstream of the dam. Santa Cruz Creek discharge (USGS 11124500) was selected as the trigger because it represents a relatively large, unaltered subwatershed upstream of Bradbury Dam with ongoing discharge monitoring, and is in close proximity to the dam and downstream river (~ 5 miles upstream).
The river-estuary-ocean connectivity water-releases are an extension of the water releases to support adult and juvenile migration and serve three purposes: (1) provide groundwater and surface-water conditions to better ensure efficiency and effectiveness of subsequent water releases for adult and juvenile steelhead migration (i.e., reduce surface-water infiltration); (2) provide emigration opportunities for estuary-rearing juvenile steelhead; and (3) provide inflow of freshwater to the estuary in the fall to ameliorate water quality conditions for
32 Indicators of Hydrologic Alteration (The Nature Conservancy 2007) analysis of Santa Ynez River flow records for USGS gage 1112600, near Bradbury Dam, resulted in median pre-dam high flow pulse magnitude of 146 cfs. 142
estuary-rearing juvenile steelhead (e.g., high salinity, high temperature, low DO).
The adult migration, spawning and incubation water-releases are intended to (1) ensure river continuity from Bradbury Dam to the ocean at a flow rate necessary to provide minimum water depth for adult steelhead passage (≥0.8 ft.) (e.g., 63 cfs near Solvang and 100 cfs near Lompoc), including a margin of safety to compensate for percolation of water into the river bed, (2) synchronize elevated main-stem river flow pulses with elevated tributary streamflow to promote access to tributary spawning habitat, and (3) provide hydraulically suitable spawning conditions in the river main-stem upstream of Solvang (>124 cfs). Combined with flows produced in the watershed downstream of the dam and dependent on the magnitude and duration of such flows, these water-releases are on occasion expected to increase complexity and extent of hydraulic conditions that support high quality adult migration (267 to 2,400 cfs) and spawning (~200 to 550 cfs) in the Santa Ynez River (see Figure 2-19).
Additionally, these water releases would provide periodic high-quality smolt emigration conditions in the river (e.g., 85 to 450 cfs near Lompoc).
The juvenile migration water-releases extend the adult migration water-releases but are independent of the adult migration water-releases because juvenile steelhead migrate for an extended period following a discharge pulse and during periods of low or no distinct discharge pulse. The water-release initiation and cessation triggers were derived from a recent assessment of flow-based migration opportunities for juvenile steelhead in Santa Ynez River Watershed below Bradbury Dam (O’Dowd et al. 2014). This assessment estimated a minimum migration-flow of 22 cfs relative to stream-channel hydraulic controls, a minimum passage-flow of 5.6 cfs based on CDFG (2012) protocols (i.e., minimum water depth of 0.4 ft. over 10% contiguous riffle cross-section), and a minimum flow for connectivity with the Santa Ynez River of 1.0 cfs. Salsipuedes Creek discharge (USGS 11132500) was selected as the trigger because it is the largest and downstream-most steelhead producing subwatershed below Bradbury Dam and has ongoing discharge monitoring, providing a good indicator for when juvenile steelhead are likely emigrating from tributary streams on their seaward migration or moving between tributary streams and the main-stem river.
The water releases for juvenile migration are intended to provide flow continuity in the Santa Ynez River from Bradbury Dam to the estuary or ocean, in synchrony with tributary streams, sufficient to allow volitional movement of juvenile steelhead between tributary streams and the river main-stem and emigration to the ocean or estuary. As a measure of sufficiency, we applied minimum migration-flows and minimum passage-flows for the Santa Ynez River corresponding to flows in Salsipuedes Creek. That is, when Salsipuedes Creek reaches or exceeds the minimum migration-flow of 22 cfs and until flows recede to the minimum passage-flow of 5.6 cfs, Reclamation shall conduct water releases at a rate sufficient to maintain minimum migration-flows in the river main-stem measured at the H-Street (USGS 11134000) and Solvang (USGS 11128500) gages. The estimated minimum migration-flows for juvenile steelhead at these two locations are 38 cfs and 42 cfs, respectively (O’Dowd et al. 2014). Because juvenile steelhead have frequently been observed migrating within and from Salsipuedes Creek at flows between 1.0 cfs and 5.6 cfs, Reclamation shall conduct water releases at a rate sufficient to maintain flow continuity in the Santa Ynez River from Bradbury Dam to the estuary equal to or greater than the minimum passage-flow (10 cfs) 143
measured at the H-Street gage when flows in Salsipuedes Creek are between 1.0 cfs and 5.6 cfs.
The water releases to support expression of juvenile life-history pathways correspond to lowflow conditions relative to a hydraulic threshold where habitat complexity is most limited (≤10 cfs; see O’Dowd et al. 2014) and the lower range of flows expected to provide suitable rearing habitat for juvenile steelhead (age 0+, Figure 2-19) in this river segment. Minimum flows from January through June represent the monthly low flows (75th percentile) calculated for the period prior to Bradbury Dam, yet after completion of Gibraltar Dam (1930-1952). 33 Minimum flows from July through December (≥10 cfs) are intended to maintain water temperature within thermally suitable limits34 for juvenile steelhead as informed by Bureau of Reclamation (2013a) and Boughton et al. (2105).
33 Indicators of Hydrologic Alteration (The Nature Conservancy 2007) analysis of Santa Ynez River flow records for USGS gage 1112600, near Bradbury Dam.
34 Boughton et al. (2015) defines thermally suitable as maximum daily temperature <29C and daily mean temperature <25C; thermally stressful occurs at temperature >21C. 144
Table 2-13. Water release schedule from Bradbury Dam (Q means stream or river discharge or flow).
Water-release goal Timing Water releaseinitiation trigger Magnitude of water
release from
Bradbury Dam
Water releasecessation trigger1
River-estuary-ocean
connectivity
Begins on October
1, ends on June 30
≥100 cfs (daily
average Q @ Santa
Cruz Creek-USGS
11124500)
150 cfs < 37 cfs (daily
average Q @ Santa
Cruz Creek-USGS
11124500)
Adult migration,
spawning and
incubation
Begins on January
1, ends on May 31
≥100 cfs (daily
average Q @ Santa
Cruz Creek-USGS
11124500)
150 cfs < 37 cfs (daily
average Q @ Santa
Cruz Creek-USGS
11124500)
Juvenile migration Begins on January
1, ends on June 30
≥22 cfs (daily
average Q @
Salsipuedes CreekUSGS 11132500)
Provide ≥38 cfs (daily
average Q @ Santa
Ynez River, H-StreetUSGS 11134000) &
≥42 cfs (daily average
Q @ Santa Ynez River,
Solvang-USGS
11128500)
≤5.6 cfs (daily
average Q @
Salsipuedes CreekUSGS 11132500)
≤5.6 cfs (daily
average Q @
Salsipuedes CreekUSGS 11132500)
Provide ≥10 cfs (daily
average Q @ Santa
Ynez River, H-StreetUSGS 11134000)
≤1.0 cfs (daily
average Q @
Salsipuedes CreekUSGS 11132500)
Expression of
juvenile life-history
pathways
All year, except
during dry or
critically dry
water-years that
follow another dry
or critically dry
water-year2 or
during critical
drought operations3
January 1
February 1
March 1
April 1
May 1
June 1
July 1
August 1
September 1
October 1
November 1
December 1
≥15 cfs4
≥18 cfs
≥15 cfs
≥12 cfs
≥11 cfs
≥11 cfs
≥10 cfs
≥10 cfs
≥10 cfs
≥10 cfs
≥10 cfs
≥10 cfs
February 1
March 1
April 1
May 1
June 1
July 1
August 1
September 1
October 1
November 1
December 1
January 1
1. Upon reaching water release-cessation trigger, initiate water release ramp-down schedule (Table 2-11 in Bureau of Reclamation 2013a). 2. During dry or critically dry water-years that immediately follow another dry or critically dry water-year, Reclamation shall make water releases sufficient to maintain ≥5 cfs at the Highway 154 Bridge. 145
3. Critical drought operations occur when Cachuma Reservoir water-surface elevation is about 665 ft. and water releases to Hilton Creek are expected to convert from the Hilton Creek water system barge-pumps to the gravity releases or other delivery mechanisms that may be applied. Water releases are expected to be reduced to about 2.0 cfs or less based on the existing gravity system capability, and progressively decline as the reservoir water-surface elevation declines. Water releases ≥0.5 cfs will continue to be delivered to Hilton Creek through the gravity system or other supplemental delivery options such as one or more submersible pumps in the stilling basin or waterstorage tanks or both.
4. Location and manner of measurement is the same for each monthly release (instantaneous (15-min) Q measured @ Solvang-USGS 11128500).
2) Channel forming flows—The biological opinion concludes that the proposed operation of Bradbury Dam appreciably alters the pattern and magnitude of river discharge, and consequently the physical and ecological processes steelhead evolved under. Specifically, the proposed operation of the dam reduces the magnitude and frequency of elevated discharge-pulses in the Santa Ynez River that facilitate geomorphic responses in the river channel. These discharge-related responses are necessary for establishing and maintaining complex habitats for steelhead (e.g., Table 2-3, alluvial river attributes associated with properly functioning riverine-habitat characteristics and conditions). Therefore, Reclamation shall conduct high magnitude water-releases from Bradbury Dam for the purpose of facilitating geomorphic responses in the river channel necessary to establish and maintain physical or biological features of critical habitat designated for the Southern California steelhead DPS. This element of the RPA includes two principal components: (a) preparation and implementation of a study plan to inform development of a high magnitude water-release plan; and, (b) preparation and implementation of a high magnitude water-release plan. (a) Preparation and implementation of a study plan to inform development of a high magnitude water-release plan. Reclamation shall prepare and submit a draft high magnitude water-release study plan to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for review no later than 120 days after the date of the final Cachuma Project biological opinion issued to Reclamation. No later than 30 days following the date of NMFS’ letter commenting on the draft high magnitude water-release study plan, Reclamation shall submit to NMFS (at the foregoing address) for review a final study plan that addresses NMFS’ comments. Reclamation must receive NMFS agreement on the final study plan prior to implementing the study plan. Upon receipt of NMFS agreement on the final study plan, Reclamation shall commence implementing the final high magnitude water-release study plan in accordance with the schedules provided therein.
The purpose of this study is to define the timing, frequency, duration and magnitude of river discharges necessary to establish and maintain physical or biological features of critical habitat designated for the Southern California steelhead DPS. The study plan shall include but not be limited to: (1) a statement of study objectives (e.g., informed by Tables 2-3, 2-6, 2-7 and 2-9 in this biological opinion, including moderating the effects of beaver dams and encroachment of vegetation in the active river channel); (2) identification of relevant information used to inform development of the study plan (e.g., existing monitoring data, literature, research and case-studies); (3) a detailed description of data collection and analytical methods, including modeling, that will be used to conduct the study; (4) a description of anticipated constraints to performing the study 146
(e.g., access to specific study sites or reaches in the river) and the approaches or assumptions for resolving such constraints; and, (5) a detailed schedule for conducting and completing the study, and producing a draft report of the study findings.
Reclamation shall submit to NMFS the draft high magnitude water-release study findings report for review and comment. No later than 45 days following the date of NMFS’ letter commenting on the draft findings report, Reclamation shall submit to NMFS for review a final high magnitude water-release study findings report that addresses NMFS’ comments. Reclamation must receive NMFS agreement for the final findings report prior to preparing the high magnitude water-release plan under RPA sub-element 2(b). (b) Preparation and implementation of a high magnitude water-release plan.
Reclamation shall prepare and submit a draft high magnitude water-release plan to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for review no later than 180 days after receiving NMFS agreement on the final high magnitude water-release study findings report under RPA sub-element 2(a).
No later than 60 days following the date of NMFS’ letter commenting on the draft high magnitude water-release plan, Reclamation shall submit to NMFS (at the foregoing address) for review a final high magnitude water-release plan that addresses NMFS’ comments. Reclamation must receive NMFS agreement for the final water-release plan prior to implementing the plan. Upon receipt of NMFS agreement on the final waterrelease plan, Reclamation shall commence implementing the final high magnitude waterrelease plan in accordance with the schedules provided therein.
The purpose of the high magnitude water-release plan is to prescribe water-releases from Bradbury Dam that are commensurate with the pattern and magnitude of Santa Ynez River Watershed discharge-pulse events upstream of the dam (e.g., Table 2-14) and of sufficient frequency, duration and magnitude to facilitate geomorphic responses in the river channel downstream of the dam necessary to establish and maintain physical or biological features of critical habitat designated for the Southern California steelhead DPS. The plan shall include, but not be limited to: (1) a clear statement of the goal(s) and objectives that form the basis for developing the water-release plan; (2) a summary of the findings obtained from RPA sub-element 2(a) and other research or case-studies used to inform development of the water-release plan (e.g., flood frequency analysis (Table 2- 14), Harrison 201435); (3) a clear description of the criteria and procedures for conducting high magnitude water-releases (operations plan) that includes, but is not limited to, (a) discharge-based triggers for conducting water releases, (b) proportionate frequency, duration and magnitude of water releases relative to river discharge upstream of the dam (Cachuma Reservoir inflow), and (c) mechanisms for ensuring timely and accurate implementation of water releases (e.g., storm forecasting, reservoir inflow prediction modeling, automated river-discharge notification system); (4) a description of specific monitoring and analytical methods that will be used to quantify geomorphic and habitat
35 The findings of this research on geomorphic responses in the Santa Ynez River below Bradbury Dam to a range of river discharges predicted the following: riffles and bars are almost completely stable at a peak discharge of 1,300 cfs; 77, 75 and 52% of pool, riffle and bar areas, respectively, are partially or fully mobilized at a peak discharge of 6,100 cfs; and, 79, 85 and 89% of pool, riffle and bar areas, respectively, are mobilized at a peak discharge of 20,000 cfs.
147
responses in the river resulting from implementation of high magnitude water-releases (effectiveness monitoring that will be incorporated in subsequent revisions to the Implementation and Effectiveness Monitoring Plan prescribed under RPA element 5); (5) a description of the process for resolving uncertainties identified during plan development and implementation, including climate change, and identifying and implementing modifications to the operating criteria and procedures based on monitoring results and applicable research (adaptive management plan that will be incorporated in subsequent revisions to the Implementation and Effectiveness Monitoring Plan prescribed under RPA element 5); (6) a presentation of conceptual-level design alternatives (i.e., structural modifications to dam) if necessary for conducting high magnitude waterreleases from Bradbury Dam (i.e., not relying on reservoir spills alone), including descriptions and schematics of sufficient detail to inform selection of one or more alternatives to advance to feasibility analysis (or similar process); and, (7) a detailed schedule for implementing high magnitude water-releases from Bradbury Dam that includes, but is not limited to (a) selecting preferred conceptual-level design alternative(s) to advance to feasibility analysis (or similar process), (b) completing detailed design(s) and feasibility analysis (or similar process), (c) conducting appropriate environmental and regulatory compliance review and approval (e.g., ESA, Clean Water Act, National Environmental Policy Act), and (d) completing structural modifications to Bradbury Dam if necessary for conducting high magnitude water-releases. 148
Table 2-14. Santa Ynez River Watershed flood frequency analysis for two gaging stations upstream of Bradbury Dam: (A) Santa Ynez River and (B) Santa Cruz Creek. (A) USGS 11123500—Santa Ynez River below Los Laurels Canyon near Santa Ynez, California. (B) USGS 11124500—Santa Cruz Creek near Santa Ynez, California. 3) Gravel augmentation—The biological opinion concludes that the proposed action will continue to result in reduced discharge of coarse sediment (e.g., gravel-sized particles) downstream of Bradbury Dam, which will diminish the value of freshwater spawning and rearing sites in the river main stem. Therefore, Reclamation shall augment coarse sediment supplies in the Santa Ynez River downstream of Bradbury Dam to offset the sediment deficit resulting from the proposed action to restore physical attributes and ecological function of the river for endangered steelhead. This element of the RPA includes two principal components: (a) preparation and implementation of a study plan to quantify sediment deficit and sediment transport capacity resulting from the continued presence and operation of Bradbury Dam, and to estimate annual and per-significant discharge event volumes of coarse sediment needed to establish and maintain equilibrium; and, (b) preparation and implementation of a plan for gravel augmentation on an ongoing basis (gravel augmentation plan).
(a) Preparation and implementation of a study plan to quantify sediment deficit.
Reclamation shall prepare and submit a draft sediment study plan to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for review no later than 120 days after the date of the final Cachuma Project biological Annual Recurrence USGS
Exceedence Interval Bulletin 17B
Probability Estimate Lower Upper
(years) (cfs) (cfs) (cfs)
0.8 1.25 111.3 54.5 206.7
0.6667 1.50 408.3 220.7 725.5
0.5 2.00 1,425 803 2,561
0.4292 2.33 2,313 1,304 4,242
0.2 5 11,890 6,342 24,690
0.1 10 30,710 15,390 70,730
0.04 25 75,440 35,140 194,200
95 % Confidence Interval
Limits for Bull. 17B
Estimates
Annual Recurrence USGS
Exceedence Interval Bulletin 17B
Probability Estimate Lower Upper
(years) (cfs) (cfs) (cfs)
0.8 1.25 239.2 166.6 327.9
0.6667 1.50 480.9 352.1 644.7
0.5 2.00 935.7 698.7 1,262
0.4292 2.33 1,209 902 1,647
0.2 5 2,844 2,064 4,122
0.1 10 4,632 3,258 7,057
0.04 25 7,296 4,954 11,720
95 % Confidence Interval
Limits for Bull. 17B
Estimates
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opinion issued to Reclamation. No later than 45 days following the date of NMFS’ letter commenting on the draft sediment study plan, Reclamation shall submit to NMFS (at the foregoing address) for review a final study plan that addresses NMFS’ comments.
Reclamation must receive NMFS agreement on the final study plan prior to implementing the plan. Upon receipt of NMFS agreement on the final study plan, Reclamation shall commence implementing the final sediment study plan in accordance with the schedules provided therein.
The purpose of this study is to estimate the amount (volume) and extent (river distance or location) of sediment deficiency, including particle-size disparity, and sediment transport capacity in the Santa Ynez River below Bradbury Dam to inform preparation of the gravel augmentation plan. The study plan shall include but not be limited to: (1) a statement of study objectives; (2) a description of data collection and analytical methods that will be used; (3) a description of anticipated constraints to performing the study (e.g., access to specific study sites or reaches in the river) and the approaches or assumptions for resolving such constraints; and, (4) a detailed schedule for conducting and completing the study, and producing a draft report of the study findings.
Reclamation shall submit to NMFS the draft sediment study findings report for review and comment. No later than 30 days following the date of NMFS’ letter commenting on the draft findings report, Reclamation shall submit to NMFS for review a final sediment study findings report that addresses NMFS’ comments. Reclamation must receive NMFS agreement for the final findings report prior to preparing the gravel augmentation plan under RPA sub-element 3(b).
(b) Preparation and implementation of a gravel augmentation plan. Reclamation shall prepare and submit a draft gravel augmentation plan to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for review no later than 120 days after receiving NMFS agreement on the final sediment study findings report under RPA 3(a). No later than 45 days following the date of NMFS’ letter commenting on the draft gravel augmentation plan, Reclamation shall submit to NMFS (at the foregoing address) for review a final gravel augmentation plan that addresses NMFS’ comments. Reclamation must receive NMFS agreement for the final gravel augmentation plan prior to implementing the plan. Upon receipt of NMFS agreement on the final gravel augmentation plan, Reclamation shall commence implementing the final gravel augmentation plan in accordance with the schedules provided therein.
The plan shall include, but not be limited to: (1) a clear statement of the goal(s) and objectives that form the basis for developing the gravel augmentation plan; (2) a summary of the findings obtained from RPA sub-element 3(a) and other pertinent case studies used to inform development of the plan; (3) a description and delineation of selected sediment augmentation areas and dispersal mechanisms (e.g., active placement to restore bars and riffles, active injection during high river discharge events, and strategic stockpiling for passive dispersal), and relative quantities and size-class distribution of supplemental gravel; (4) a description of natural riverine gravel sources and/or collection sites to be utilized (i.e., Santa Ynez River Watershed), including detailed gravel mining plan(s); (5) a description of specific data collection and analytical methods that will be used to quantify geomorphic and habitat responses in the river resulting from implementation of the plan (effectiveness monitoring); (6) a clear 150
description of the process for (a) resolving uncertainties identified during plan development and implementation, (b) considering new information (e.g., effectiveness monitoring results, changed conditions, and applicable research), and (c) identifying and implementing modifications to the gravel augmentation plan, as well as the effectiveness monitoring plan, based on monitoring results and applicable research and case studies (adaptive management plan); and, (7) a detailed schedule for implementing the gravel augmentation plan on an ongoing basis, including conducting appropriate environmental and regulatory compliance review and approval (e.g., ESA, Clean Water Act, National Environmental Policy Act).
4) Bradbury Dam fish passage—The biological opinion concludes that the proposed action will continue to result in watershed-scale habitat fragmentation for steelhead in the Santa Ynez River Watershed. Bradbury Dam prevents steelhead from accessing abundant and persistent spawning and rearing habitat upstream of the dam and reduces efficient interchange between the resident form and anadromous form of O. mykiss. The proposed action offers no solution for ameliorating the watershed-scale habitat fragmentation resulting from the Cachuma Project. Because the Santa Ynez River Watershed downstream of Bradbury Dam alone is not expected the support a viable population of steelhead, Reclamation shall provide passage of adult and juvenile steelhead at or around Bradbury Dam. This element of the RPA involves three principal steps: (a) preparation of a plan that will guide the development and assessment of steelhead-passage alternatives; (b) development and assessment of steelhead-passage alternatives; (c) preparation and implementation of a steelhead-passage implementation plan. These steps are described more fully as follows.
(a) Preparation of a plan that will guide the development and assessment of steelheadpassage alternatives at Bradbury Dam. Reclamation shall prepare a draft plan to guide the Bradbury Dam steelhead-passage assessment and submit this plan to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for review no later than 12 months after the date of the final Cachuma Project biological opinion issued to Reclamation. No later than 60 days following the date of NMFS’ letter commenting on the draft steelhead-passage assessment plan, Reclamation shall submit to NMFS (at the foregoing address) for review a final plan that addresses NMFS’ comments. Reclamation must receive NMFS agreement for the final steelheadpassage assessment plan prior to implementing the plan. Upon receipt of NMFS’ agreement on the final steelhead-passage assessment plan, Reclamation shall implement the final plan in accordance with the schedules provided therein.
The purpose of this plan is to describe the methods and schedules that will be used to guide the process for conducting and completing the development and analysis of steelhead-passage alternatives. To develop the plan, Reclamation shall undergo the following or similar process: (1) no later than 60 days after receipt of this biological opinion, Reclamation shall convene at least one meeting with NMFS for the purpose of discussing expectations and elements that will form the basis of the plan, including identification of appropriate professional expertise and experience necessary to develop and analyze steelhead-passage alternatives; (2) following the above referenced coordination meeting(s), Reclamation shall assemble a team of professionals (fishpassage design team) with expertise and experience in the evaluation of fish passage at 151
dams to develop and analyze steelhead-passage alternatives for Bradbury Dam; (3) Reclamation shall convene a “kick-off” meeting among the fish-passage design team, Reclamation, NMFS, USFWS, and CDFW for the purposes of (a) introducing respective points of contact, (b) discussing expectations of the assessment, and c) identifying protocols and mechanisms for exchanging information; (4) Reclamation, in coordination with the fish-passage design team, shall prepare a plan for guiding the steelhead-passage assessment that includes but is not limited to (a) a clear statement of objectives to guide the development and analysis of a range of steelhead-passage alternatives (e.g., volitional and non-volitional, with preference for volitional fish-passage), (b) identification of published fish-passage design guidelines and criteria, and investigations of steelhead behavior, ecology, and habitat requirements to inform the assessment, (c) a list of information to be compiled and individual studies to be conducted to inform the steelhead-passage assessment36, (d) a clear description of the methods that will be used or anticipated to be used to perform the various tasks related to the development and analysis of steelhead-passage design alternatives (e.g., numerical and physical hydraulic modeling), (e) a clear description of the process and objective decision criteria for judging prospective steelhead-passage alternatives or components thereof, (f) a schedule of tasks, milestones and work-product review periods to monitor and track performance of the steelhead-passage assessment over time, including completing and reporting the development and assessment of steelhead-passage alternatives and completing the steelhead-passage implementation plan, and (g) a contingency program to effectively address and resolve unforeseen circumstances in a timely manner. (b) Development and assessment of Bradbury Dam steelhead-passage alternatives.
Upon receipt of NMFS’ written agreement to the plan for guiding the development and assessment of steelhead-passage alternatives at Bradbury Dam as provided in subelement 4(a), Reclamation and the design team shall conduct and complete the agreedupon steelhead-passage alternative development and assessment as set forth in the plan.
As provided in the agreed upon schedule in the plan, Reclamation shall prepare and submit a draft report on the development and assessment of Bradbury Dam steelheadpassage alternatives to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for review. No later than 60 days following the date of NMFS’ letter commenting on the draft report, Reclamation shall submit to NMFS (at the foregoing address) for review a final report on the development and assessment of Bradbury Dam steelhead-passage alternatives that addresses NMFS’ comments.
Reclamation must receive NMFS agreement for the final report prior to preparing the draft steelhead-passage implementation plan.
(c) Preparation of a Bradbury Dam steelhead-passage implementation plan. As provided in the schedule in the agreed upon plan to assess steelhead passage at Bradbury
36 For example, a fish passage engineering report identified several informational items and studies that would be required for investigating fish-passage alternatives at Bradbury Dam including a topographic survey in vicinity of the dam and a study to determine the ability of juvenile steelhead to migrate through the reservoir. This report is contained in Reclamation’s Compliance binder for the [2000] biological opinion for the operations and maintenance of the Cachuma Project on the Santa Ynez River in Santa Barbara County, California (Bureau of Reclamation 2011e).
152
Dam (sub-element 4(a)), Reclamation shall prepare and submit a draft Bradbury Dam steelhead-passage implementation plan to NMFS’ California Coastal Office (501 W.
Ocean Blvd., Suite 4200, Long Beach, California 90802) for review. No later than 60 days following the date of NMFS’ letter commenting on the draft plan, Reclamation shall submit to NMFS (at the foregoing address) for review a final Bradbury Dam steelheadpassage implementation plan that addresses NMFS’ comments. Reclamation must receive NMFS agreement for the final steelhead-passage implementation plan prior to implementing the plan. Upon receipt of NMFS agreement on the final plan, Reclamation shall implement the steelhead-passage implementation plan in accordance with the schedules provided therein.
The steelhead-passage implementation plan shall include but not be limited to: (1) a summary of the findings obtained from the steelhead-passage assessment and all related studies; (2) a detailed description of the preferred alternative for restoring steelhead access to and from historical spawning and rearing habitats upstream of Bradbury Dam; (3) a detailed description of the actions, procedures and schedule for ensuring reliability and performance of the preferred alternative for steelhead passage at or around Bradbury Dam; and, (4) a detailed schedule for implementing and completing the elements of the plan, including preparation of construction plan(s), conducting appropriate environmental and regulatory compliance review and approval (e.g., ESA, Clean Water Act, National Environmental Policy Act) and implementation of the preferred alternative steelheadpassage at or around Bradbury Dam. 5) Implementation and effectiveness monitoring—The biological opinion concludes that Reclamation’s proposed Lower Santa Ynez River Monitoring Plan is not expected to be effective for minimizing effects of the action. In particular, Reclamation’s plan lacks the necessary framework to reliably assess, let alone detect and minimize, effects that are due to the proposed action. In addition, the plan content is insufficient to effect modifications to the proposed operations of Bradbury Dam as necessary to minimize effects and evaluate the efficacy of a modification. Therefore, Reclamation shall develop and then institute an Implementation and Effectiveness Monitoring Plan (IEMP) for the proposed action. (a) Purpose of the IEMP. The purpose of the IEMP is to detail (1) the process methods and protocols Reclamation will implement to ensure operations of Bradbury Dam comply with the water releases specified in RPA element 1 and developed under element 2, (2) describe the field and analytical methods Reclamation will apply to evaluate the efficacy of Bradbury Dam operations for providing physical or biological features of critical habitat, in particular, the essential habitat functions consistent with the migration, spawning, and rearing needs of adult and juvenile steelhead, and (3) explain how Reclamation would use findings obtained from empirical field studies to inform modifications of Bradbury Dam operations for the purpose of complying with the water releases specified in RPA element 1 and developed in RPA element 2. Reclamation shall submit the draft IEMP to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for review no later than 90 days after the date of the final Cachuma Project biological opinion issued to Reclamation. No later than 30 days following the date of NMFS’ letter commenting on the draft IEMP, Reclamation shall submit to NMFS (at the foregoing address) for review a final IEMP that addresses NMFS’ comments. Reclamation must receive final NMFS agreement for the final IEMP 153
prior to implementing the final IEMP. Upon receipt of final NMFS agreement on the IEMP, Reclamation shall implement the final IEMP in accordance with the schedules provided therein. Reclamation shall prepare and submit to NMFS (at the foregoing address) annual reports that detail the findings from the effectiveness monitoring.
Because development and implementation of element 2 of the RPA will not occur until a future time, the IEMP shall be revised accordingly and also must be reviewed and accepted by NMFS prior to instituting proposed modifications. (b) Content of the IEMP. The IEMP shall include (1) an implementation plan, (2) an effectiveness-monitoring plan, and (3) an adaptive-management plan. (c) Content of the implementation plan. The implementation plan shall include (1) a description of the process-oriented standard procedures that operators of Bradbury Dam will follow to ensure Bradbury Dam operations comply with the water releases specified in RPA element 1 and developed under element 2 (the procedural description shall include individual events or activities, or the logical relationship between the events or activities, the specific operations that would be performed, the implementation steps or sequences in which the operations would be performed, and the chain of communication), (2) a description of the specific precautionary measures that operators of Bradbury Dam will undertake to ensure that no water-release lapse at Bradbury Dam occurs, (3) a description of the contingency measures that operators will implement should an accidental lapse in water release at Bradbury Dam occur, including the operations performed for resolving specific categories of incidents (e.g., interruptions in chain of communication, contingency measures to be implemented in case of an accidental lapse in water release), (4) a description of the specific triggers and procedures that operators will follow to transition from one type of water release to another, and (5) a description of the specific ramping rates and procedures that operators will institute to minimize stranding and related effects on steelhead.
(d) Content of the effectiveness-monitoring plan. This plan shall describe the field and analytical methods that Reclamation will follow to evaluate the efficacy of Bradbury Dam operations (i.e., water releases specified in RPA element 1 and developed under element 2) to create and maintain physical or biological features of critical habitat for adult and juvenile steelhead. To this end, the plan shall incorporate and expand upon the field investigations specified in Table 2-15. In addition, the plan shall include (1) biological goals and objectives (including criteria) of the effectiveness monitoring, (2) a description of the specific hypotheses that will be evaluated as part of the effectiveness monitoring, (3) a description of the biological, physical, and physicochemical response variables that will be quantified to assess the effectiveness of the water releases for providing physical or biological features of critical habitat, (4) a description of the specific field methods that will be used to quantify the response variables and evaluate the identified hypotheses, (5) a description of the field-sampling schedules for each of the response variables and specific hypotheses, and (6) the analytical methods and inferential models that will be used to evaluate or test specific hypotheses. Specific details of various aspects of this plan, including schedules, shall be developed by Reclamation in cooperation with and with agreement from NMFS prior to implementation of this plan, consistent with requirements set forth in RPA sub-element 5(a). Reclamation shall provide to NMFS (at the foregoing address) all raw data (in electronic and hardcopy 154
formats) that is collected as part of the effectiveness-monitoring plan, as such data become available.
(e) Content of the adaptive-management plan. Reclamation shall develop this adaptive management plan for operation of the Cachuma Project, including all related appurtenances. The principal purpose of this plan is for Reclamation to detail the processes and procedures Reclamation will follow to inform future modification of Bradbury Dam operations, including refinement of the water releases specified in RPA element 1 and developed under element 2, to avoid the likelihood of jeopardizing the continued existence of the Southern California steelhead DPS and destroying or adversely modifying critical habitat designated for this species. In this regard, Reclamation will rely upon the findings obtained from the field investigations that are the basis of the effectiveness-monitoring plan, as required in RPA sub-element 5(d), to inform any and all future modifications of the operations of Bradbury Dam that may affect endangered steelhead or critical habitat for this species. To this end, Reclamation’s adaptive-management plan shall define and implement a protocol that will respond to new information or changing conditions, detect and reconcile deficiencies or problems in a timely manner, and incorporate feedback loops that link implementation and monitoring to a decision-making process that results in appropriate changes in operations to avoid the likelihood of jeopardizing the continued existence of the Southern California steelhead DPS and destroying or adversely modifying critical habitat designated for this species.
Specific details of various aspects of this plan, including schedules, shall be developed by Reclamation in cooperation with and agreement from NMFS prior to implementation of this plan, consistent with requirements set forth in RPA sub-element 5(a). (f) Compliance monitoring by independent entity. Reclamation shall retain an independent entity who will perform routine, comprehensive quarterly appraisals for the purposes of (1) establishing whether Reclamation’s operation of the Cachuma Project and South-Coast Conduit are compliant with this biological opinion (i.e., RPA and terms and conditions) including the water releases specified in RPA element 1 and developed under element 2, (2) identifying the type(s), cause(s), and implication(s) for any evidence of non-compliance, and (3) documenting the appraisal findings in a quarterly report that is submitted to NMFS (501 West Ocean Blvd., Suite 4200, Long Beach, California, 90802) no later than 14-days following the completion of a quarterly appraisal. The selected entity must not have recent (i.e., past 2 years) affiliation with Reclamation or the member units in relation to the Cachuma Project, and shall possess a well-established record of compliance monitoring for appraising organizational conformity with state or federal regulation, including permit, order, or license requirements. Reclamation must receive written NMFS agreement for a selected entity no later than 180 days following the date of the final biological opinion for the Cachuma Project. Reclamation shall provide the entity with reasonable access to any and all information, data, files, records, logs, personnel, facilities, river and creek reaches, equipment, and instrumentation, which are necessary for fully evaluating Reclamation’s compliance with this biological opinion (i.e., RPA and terms and conditions).
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Table 2-15. Investigations that are to be the basis of Reclamation’s effectiveness-monitoring plan, as stipulated in reasonable and prudent alternative (RPA) sub-element 5(d). A key outcome of each investigation is the development of information that would guide management of Bradbury Dam operations for the purpose of creating and maintaining physical or biological features of critical habitat of critical habitat designated for the Southern California steelhead DPS. Information regarding the measured variable and field method is decidedly abbreviated and solely intended to provide general insights regarding the scope of study. In accordance with RPA sub-element 5(d), the content of the effectiveness-monitoring plan, including the specific measured variables and field methods, would be developed in coordination with NMFS.
Monitoring topic Monitoring objective Measured variable Field method Estuary-ocean
connectivity
Establish relationship between
estuary-ocean connectivity and
river discharge1
.
• Frequency and duration of
connectivity.
• Degree of connectivity.
• River-discharge metrics.
• Wave-action metrics.
• Combination of
qualitative and
quantitative
metrics.
Adult steelhead
migration
Establish relationship between
adult steelhead migration and
river discharge.
• Timing of steelhead entry and
departure.
• Number of steelhead.
• Individual rate of upstream and
downstream migration.
• River-discharge metrics.
• Fixed fishcounting
stations.
• Fish tagging and
tracking.
Steelhead
spawning,
incubation, and
emergence
Establish relationship between
steelhead spawning, incubation,
and emergence, and river
discharge.
• Spawning behavior
• Timing of redd construction.
• Redd location and disposition.
• Fry abundance.
• River-discharge metrics.
• Combination of
visual methods
and field
measurements.
Main-stem
rearing
Establish relationship between
seasonal abundance of juvenile
steelhead in the main stem and
river discharge.
• Seasonal abundance, size and
distribution of age-0, age-1, and
age-2 steelhead.
• River-discharge metrics.
• Snorkeling and
electrofishing.
• Fish tagging and
tracking.
Smolt production
and emigration
Establish relationship between
smolt emigration and river
discharge.
• Timing of entry in main stem,
estuary, and ocean.
• Size at entry in main stem, estuary,
and ocean.
• Number of smolts entering main
stem, estuary, ocean.
• Fixed fishcounting
stations.
• Fish tagging and
tracking.
Juvenile
steelhead
expression of
life-history
pathways
Establish relationship between
hydrologic continuity
throughout main-stem river,
including at tributary
confluences, and river discharge.
• Movements of juvenile steelhead
throughout and between main-stem
river, tributaries, and estuary.
• Size and age of migrants.
• River-discharge metrics.
• Metrics of the wetted channel.
• Fixed fishcounting
stations.
• Fish tagging and
tracking.
1. Refers to pattern and magnitude of river discharge owing to water releases from Bradbury Dam. One or more monitoring objectives may require monitoring discharge and other characteristics of tributaries to the main-stem river.
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6) South Coast Conduit steelhead migration—The biological opinion concludes that South Coast Conduit impedes or precludes migration of juvenile and adult steelhead in several south coast streams. The South Coast Conduit is presently exposed in at least six streams, causing a barrier to steelhead migration and diminishing the value of critical habitat for the conservation of this species. We expect the conduit will become exposed in the future at other stream intersections, creating additional barriers to steelhead migration. Therefore, this element of the RPA has 2 components: (a) remediate the existing steelhead-passage barriers resulting from the South Coast Conduit; and, (b) prepare and implement a plan for detecting and remediating future steelhead-passage barriers resulting from the South Coast Conduit. (a) Reclamation shall remediate the existing barriers to steelhead passage resulting from the South Coast Conduit according to the schedule below (Table 2-16). Reclamation shall submit draft designs for the remediation of each existing barrier in accordance with the schedule below (Table 2-16) to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for review. No later than 30 days following the date of NMFS’ letter commenting on each draft South Coast Conduit steelheadpassage designs, or as otherwise specified in NMFS’ comment letter, Reclamation shall submit to NMFS (at the foregoing address) for review a final design that addresses NMFS’ comments. Reclamation must receive NMFS agreement for steelhead passage remediation designs prior to implementing the final design. All construction-related work within the stream shall be conducted during the dry season when stream flow is minimal or absent in the affected area.
(b) Reclamation shall prepare and implement a plan for detecting and then remediating impediments or barriers to steelhead passage resulting from future exposure of the South Coast Conduit at stream intersections. Reclamation shall submit a draft South Coast Conduit steelhead-passage monitoring and remediation plan to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for review no later than 90 days after the date of the final Cachuma Project biological opinion issued to Reclamation. No later than 30 days following the date of NMFS’ letter commenting on the draft plan, Reclamation shall submit to NMFS (at the foregoing address) for review a final South Coast Conduit steelhead-passage monitoring and remediation plan that addresses NMFS’ comments. Reclamation must receive NMFS agreement for the final South Coast Conduit steelhead-passage monitoring and remediation plan prior to implementing the plan. Upon receipt of NMFS agreement on the final plan, Reclamation shall commence implementing the final South Coast Conduit steelhead-passage monitoring and remediation plan in accordance with the schedules provided therein.
The plan shall include, but not be limited to the following: (a) a schedule for inspecting the South Coast Conduit stream intersections to detect pipeline exposure, including maintenance and environmental triggers to guide the inspection schedule; (b) a description of the procedures and methods for assessing steelhead passage at exposed pipeline crossings, including the timing of such assessments relative to detection of pipeline exposure; (c) an outline of prioritized approaches for remediating steelhead passage impediments, including application of the most current NMFS and CDFW fish- 157
passage design guidelines and criteria37 with preference for “stream simulation” design methods, and; (d) a schedule for preparing, reviewing (e.g., coordination and consultation with state and federal resources agencies), and implementing plans to remediate exposed pipeline crossings that impede steelhead passage; and, (e) identification of funding allocations and other funding sources to ensure timely remediation of steelhead-passage impediments.
Table 2-16. Schedule for designing and implementing steelhead-passage remediation in selected streams intersected by the South Coast Conduit.
Stream Steelhead-passage design
completion date1
Steelhead-passage
remediation completion
date
Mission Creek2 January 2018 November 2018
Maria Ygnacio Creek3 January 2018 November 2018
Montecito Creek January 2019 November 2019
Las Vegas Creek January 2019 November 2019
Romero Creek January 2020 November 2020
Carneros Creek January 2020 November 2020
1 To facilitate review and revision of fish-passage deigns, Reclamation must submit draft designs to NMFS at least 90 days from expected completion date of final design (i.e., November of the preceding year). 2 Cachuma Operation and Maintenance Board, on behalf of Reclamation, conducted emergency repair and protection of the South Coast Conduit in Mission Creek in October 2015, and committed to designing steelhead-passage remediation for this site by October 2016. NMFS has not been informed whether or not the design was developed.
3 South Coast Habitat Restoration was awarded a grant for designing steelhead-passage remediation for this site, and five other sites in Maria Ygnacio Creek. The design is expected to be completed by January 2017. 7) South Coast Conduit chlorinated-water discharge—The biological opinion concludes that proposed discharges of water from the South Coast Conduit and Carpinteria Reservoir that have been treated (disinfected) with chlorine are expected to be harmful to steelhead. The biological assessment does not provide sufficient detail to determine the effectiveness of dechlorinating water prior to release (i.e., residual chlorine levels). Because even low
37 The following fish-passage design guidelines and criteria shall be applied unless otherwise revised or agreed to in writing by NMFS: Anadromous salmonid passage facility design (National Marine Fisheries Service 2011c), and California salmonid stream habitat restoration manual, part XII, fish passage design and implementation. 158
concentrations of chlorine can cause sub-lethal and lethal effects to steelhead, a cautionary approach regarding proposed discharge of treated water is appropriate. Therefore, Reclamation shall implement measures to ensure treated water is not discharged into streams at such times or locations where the treated water may mix with standing or flowing water.
Such measures may include discharging treated water into a container, upland areas, or dry stream channel.
8) Glen Annie Dam operations—The biological opinion concludes that proposed operation of Glen Annie Dam alters the pattern and magnitude of stream discharge in West Fork Glen Annie and Glen Annie creeks. This is expected to reduce or preclude development and maintenance of the freshwater migration corridor and spawning and rearing areas for steelhead in these streams, diminishing the value of critical habitat for the conservation of this species. Therefore, Reclamation shall operate Glen Annie Dam as a run-of-river system (i.e., outflow equals natural inflow) to allow development and maintenance of physical or biological features of critical habitat designated for the Southern California steelhead DPS.
2.8.1 Consistency of the Reasonable and Prudent Alternative with Regulations Implementing Section 7 of the ESA
Regulations (50 CFR 402.02) implementing section 7 of the ESA define reasonable and prudent alternatives (RPA) as alternative actions identified during formal consultation that: (1) can be implemented in a manner consistent with the intended purpose of the action; (2) can be implemented consistent with the scope of the action agency’s legal authority and jurisdiction; (3) are economically and technologically feasible; and, (4) that NMFS believes would avoid the likelihood of jeopardizing the continued existence of listed species or resulting in the destruction or adverse modification of critical habitat.
The RPA can be implemented in a manner consistent with the intended purpose of the action.
The intended purpose of the action is providing domestic and agricultural water supplies to communities along Santa Barbara’s South Coast and the Santa Ynez Valley; operations include winter storm operations to protect downstream life and property and water releases for Southern California steelhead conservation38 (Bureau of Reclamation 2013a). The RPA will not preclude Reclamation from capturing, storing and distributing Santa Ynez River water for the purposes described above. The RPA (i.e., element 2) is expected to enhance Reclamation’s ability to protect downstream property and life by increasing the capacity for controlled high magnitude water-releases from Bradbury Dam and reducing the frequency of uncontrolled spills.
And, the RPA is expressly intended to promote the conservation of steelhead. Therefore, the RPA can be implemented consistent with the intended purposes of the action.
Regarding the operation of Glen Annie Dam, the RPA is consistent with the purpose of the action because this dam is operated only for the purpose of capturing out-of-basin water (i.e., Santa Ynez River water) discharged from the Tecolote Tunnel during periodic inspection and maintenance (i.e., approximately every 6 years). Water captured in Glen Annie Reservoir (i.e.,
38 Under ESA section 3(3), the term conservation means to use and the use of all methods and procedures which are necessary to bring any endangered species or threatened species to the point at which the measures provided pursuant to the ESA are no longer necessary.
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Tecolote Tunnel and West Fork Glen Annie Creek discharges) is not used for any form of water supply (Bureau of Reclamation 2013a). Furthermore, authorization provided to Reclamation under the California State Water Resources Control Board permit 11309 to capture, store and distribute water in and from Glen Annie Reservoir for irrigation and domestic purposes appears to have been or may be subject to forfeiture (SWRCB 2010).
The RPA can be implemented consistent with the scope of Reclamation’s legal authority and jurisdiction. The RPA can be implemented consistent with Endangered Species Act section 7(a)(1) and (2), the Fish and Wildlife Coordination Act (16 U.S.C. 661 et seq.), Federal Water Project Recreation Act of 1965, as amended (Public Law 89-72; 79 Stat. 213, 214; 16 U.S.C. 460l et seq.), Anadromous Fish Conservation Act (Public Law 89-304; 79 Stat. 1125; 16 U.S.C. 757a et seq.), Omnibus Public Land Management Act of 2009 (Section 9504—Water Management Improvement) (Public Law 111-11; 123 Stat. 1334; 42 U.S.C. 10364), and Reclamation’s directives and standards and policy for floodplain management. Reclamation has demonstrated continued authority to undertake modifications to the Cachuma Project such as design and implementation of the Bradbury Dam seismic correction, Hilton Creek water system, and increased storage capacity of Cachuma Reservoir.
The RPA is economically and technically feasible. The RPA is expected to be economically and technically feasible because such actions have been and continue to be undertaken at or in association with other Reclamation water-project facilities (Bureau of Reclamation 2011f).
Furthermore, an inherent component to carrying out certain elements of the RPA (i.e., RPA elements 2 and 4) is assessing economic and technical feasibility to inform selection of a preferred alternative to be implemented.
NMFS believes the RPA would avoid the likelihood of jeopardizing the continued existence of endangered steelhead or resulting in the destruction or adverse modification of designated critical habitat for this species.
The elements of the RPA address those aspects of the proposed action that diminish the value of critical habitat for the conservation of steelhead, perpetuate the reduction in the amount and quality of habitat for steelhead, and continue to suppress population abundance, population growth rate, population spatial structure and population diversity of steelhead. Chief among these aspects are the lack of water releases from Bradbury Dam and Glen Annie Dam for the purpose of developing and maintaining physical or biological features of critical habitat for the Southern California steelhead DPS, and habitat loss and fragmentation resulting from the continued presence, maintenance and operation of Bradbury Dam and the South Coast Conduit.
A summary of how each element under the RPA contributes to avoiding the likelihood of jeopardizing the continued existence of endangered steelhead or resulting in the destruction or adverse modification of designated critical habitat for this species is as follows.
The first element of the RPA addresses the lack of water releases necessary to establish and maintain physical or biological features of critical habitat designated for the Southern California steelhead DPS. The RPA requires conducting meaningful water-releases from Bradbury Dam to support steelhead migration (adult and juvenile), spawning and rearing in the Santa Ynez River downstream of the dam.
The second and third elements of the RPA address the degraded habitat conditions in the Santa Ynez River resulting from the continued presence and operation of Bradbury Dam. The RPA requires conducting high magnitude water-releases and gravel augmentation to facilitate 160
geomorphic responses in the river channel to establish and maintain establish and maintain physical or biological features of critical habitat designated for the Southern California steelhead.
In addition, these two elements are necessary to make the water-releases under the first element of the RPA more reliable and effective in providing functional habitat conditions necessary to sustain physical or biological features of critical habitat designated for the Southern California steelhead DPS. The combination of these elements is also expected to increase availability of food resources (i.e., macroinvertebrate production) and growth potential of juvenile steelhead, increasing survival and readiness for an anadromous life-history.
The fourth element addresses the watershed-scale habitat fragmentation caused by Bradbury Dam. Because the Santa Ynez River Watershed downstream of Bradbury Dam is insufficient to support a viable steelhead population operation of the Cachuma Project is expected to reduce the likelihood of both survival and recovery of endangered steelhead in the wild unless passage of adult and juvenile steelhead is provided at or around Bradbury Dam.
The fifth element of the RPA provides meaningful monitoring of the effectiveness of Bradbury Dam operations for establishing and maintaining physical or biological features of critical habitat designated for the Southern California steelhead DPS. The IEMP is expected to inform in a timely manner adjustments to Bradbury Dam operations that may be necessary to avoid the likelihood of jeopardizing the continued existence of endangered steelhead or resulting in the destruction or adverse modification of designated critical habitat for this species.
The sixth element of the RPA addresses diminished function and value of freshwater migration corridors in several south coast streams. The RPA requires remediation of existing and future exposed pipeline crossings for the purpose of maintaining a functional migration corridor for volitional movement of adult and juvenile steelhead.
The seventh element of the RPA addresses potential exposure of steelhead to sub-lethal or lethal effects resulting from discharge of chlorinated water in several south coast streams. The RPA requires chlorinated water be discharged in a manner that avoids exposure to steelhead.
The eighth element of the RPA addresses the lack of water releases necessary to provide for the development and maintenance of the freshwater migration corridor and spawning and rearing habitat for steelhead in West Fork Glen Annie Creek and Glen Annie Creek downstream of Glen Annie Dam. The RPA requires conducting water-releases from Glen Annie Dam to establish and maintain physical or biological features of critical habitat designated for this species downstream of the dam.
Overall, the RPA is expected to promote an increase in the amount and quality of suitable habitat available to adult and juvenile steelhead, improve the value of critical habitat for the conservation of this species, and lead to increased population abundance, growth rate, spatial structure and diversity of steelhead over time. Accordingly, NMFS believes the RPA would avoid the likelihood of jeopardizing the continued existence of endangered steelhead and resulting in the destruction or adverse modification of critical habitat designated for this species.
2.9 Incidental Take Statement
Section 9 of the ESA and federal regulations pursuant to section 4(d) of the ESA prohibit the take of endangered and threatened species, respectively, without a special exemption. “Take” is defined as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture or collect, or to attempt to engage in any such conduct. “Harm” is further defined by regulation to include significant 161
habitat modification or degradation that actually kills or injures fish or wildlife by significantly impairing essential behavioral patterns, including breeding, spawning, rearing, migrating, feeding, or sheltering (50 CFR 222.102). “Incidental take” is defined by regulation as takings that result from, but are not the purpose of, carrying out an otherwise lawful activity conducted by the federal agency or applicant (50 CFR 402.02). Section 7(b)(4) and section 7(o)(2) provide that taking that is incidental to an otherwise lawful agency action is not considered to be prohibited taking under the ESA if that action is performed in compliance with the terms and conditions of this incidental take statement.
2.9.1 Amount or Extent of Take
Operation, maintenance and monitoring of the Cachuma Project, including implementation of the RPA, is expected to cause incidental take of the Southern California DPS of steelhead. Table 2- 17 below describes the expected types of incidental take, the life stages expected to be incidentally taken, how the incidental take is expected to occur, and the anticipated amount of incidental take resulting the proposed operation and maintenance of the Cachuma Project as modified by the RPA. This level of incidental take was estimated from the information available to us, expectations for the action area and effects of the proposed action, and knowledge of the ecology and behavior of steelhead. This take estimate may be revised in the future depending on the findings obtained from the implementation and effectiveness monitoring that is required in the reasonable and prudent alternative and this incidental take statement.
2.9.2 Effect of the Take
In the biological opinion, we determined that the amount or extent of anticipated take, coupled with other effects of the proposed action, is not likely to result in jeopardy to the species or destruction or adverse modification of critical habitat when the reasonable and prudent alternative is implemented.
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Table 2-17. Summary of the amount of incidental take anticipated to result from the proposed operation and maintenance of the Cachuma Project as modified by the RPA1 .
Source of take Steelhead life stage Type of take
Annual number of
individuals that are
anticipated to be
incidentally taken2
Monitoring: trapping,
capturing and tagging Juvenile Trap, capture ≤1,500
Juvenile Injure, kill
1 individual or 3% of
actual captures,
whichever is greater
Adult Trap, capture 50
Winter-storm operations
and high magnitude
water-releases
Embryo Injure, kill
(nest destruction)
1 nest
Juvenile Harm
(displacement/stranding) 15
Adult Harm
(displacement/stranding) 1
Water-rights releases Juvenile Harm
(displacement/stranding) 15
Critical drought
operations Juvenile Harm, kill 2003
Maintenance activities
and South Coast Conduit
fish-passage remediation
Juvenile Harm
(displacement/stranding) 300
Non-native fish removal Juvenile Harm
(displacement/stranding) 15
Fish rescue & relocation4 Juvenile Capture 500
Juvenile Injure, kill
1 individual or 5% of
actual captures,
whichever is greater
Adult Capture 1
1 This summary does not include incidental take that may occur as a result of implementing certain elements of the RPA (i.e., gravel augmentation and Bradbury Dam fish passage) because we do not currently have sufficient information and details to estimate the amount of incidental take that may occur under these elements. Therefore, additional consultation or revision to this incidental take statement may be necessary as those elements are developed.
2 Not all activities, thus amount of incidental take, will occur in all years. 163
3 Critical drought operations are expected to be infrequent (about 1 time in 50 years (Bureau of Reclamation 2013a)).
Because critical drought operations would likely only occur after multiple consecutive dry or critically dry wateryears (i.e., <15,366 ac-ft reservoir inflow) and implementation of the water-release scenario for maintaining flow only through the Hwy 154 reach, the estimated incidental take is based on the number of O. mykiss that were estimated to be present in this river reach under similar conditions (Bureau of Reclamation 2015c). 4Fish rescue and relocation is intended to reduce the likelihood of death of individual steelhead resulting from foreseeable and unforeseeable circumstances that cause areas occupied by steelhead to become dewatered (e.g., dewatering stream reaches for implementation of fish-passage remediation projects and relocating steelhead trapped or stranded resulting from various water-release scenarios, and non-native fish removal). Therefore, the annual amount of take identified for fish rescue and relocation encompasses (i.e., is not in addition to) the number of individuals that may be displaced and stranded resulting from all other identified activities except Monitoring.
2.9.3 Reasonable and Prudent Measures
“Reasonable and prudent measures” are nondiscretionary measures that are necessary or appropriate to minimize the impact of the amount or extent of incidental take (50 CFR 402.02).
NMFS believes the following reasonable and prudent measures are necessary or appropriate to minimize the impact of the amount or extent of incidental take. 1) Prepare and implement a plan to monitor and minimize displacement and stranding of steelhead owing to water-releases from Bradbury Dam conducted for downstream water rights and groundwater replenishment.
2) Prepare and implement a plan to assess the effectiveness of water-release ramping rates intended to minimize or avoid the displacement and stranding of steelhead owing to winterstorm operations. 3) Avoid or minimize interruption of water releases into Hilton Creek when inspecting, testing or maintaining the Hilton Creek Water System.
4) Ensure timely and effective removal of non-native fish species from the Santa Ynez River and Hilton Creek within Reclamation’s property boundary. 5) Prepare a critical drought operations plan to minimize the amount of habitat temporarily lost and the number of steelhead harmed or killed associated with habitat desiccation under continuous drought conditions.
6) Rescue and relocate steelhead that become or are likely to become stranded in areas subject to desiccation resulting from foreseeable or unforeseeable circumstances, as identified in Reclamation’s Cachuma Project fish rescue plan (Bureau of Reclamation 2015k). 164
2.9.4 Terms and Conditions
The terms and conditions described below are non-discretionary, and Reclamation or any applicant must comply with them in order to implement the reasonable and prudent measures (50 CFR 402.14). Reclamation or any applicant has a continuing duty to monitor the impacts of incidental take and must report the progress of the action and its impact on the species as specified in this incidental take statement (50 CFR 402.14). If the entity to whom a term and condition is directed does not comply with the following terms and conditions, protective coverage for the proposed action would likely lapse.
1) The following terms and conditions implement reasonable and prudent measure 1:
a) Reclamation shall prepare and implement a plan to monitor and minimize displacement and stranding of steelhead owing to water-releases from Bradbury Dam conducted for downstream water rights and groundwater recharge. The plan shall include, but not be limited to, (1) installing at least one fish trap at an appropriate location (e.g., Alisal Bridge near Solvang) and for sufficient duration to effectively monitor steelhead displacement and minimize or avoid stranding steelhead in areas that become dewatered when such water-releases cease, and (2) coordinating and conducting water-releases (timing, rate, and duration) to optimize the amount and quality of freshwater rearing areas during the dry season.
b) Reclamation shall submit a draft of the subject plan to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for our review no later than 90 days after the date of the final Cachuma Project biological opinion issued to Reclamation. No later than 30 days following the date of NMFS’ letter commenting on the draft plan, Reclamation shall submit to NMFS (at the foregoing address) for review a final plan that addresses NMFS’ comments. Reclamation must receive our agreement for the subject plan prior to implementing the plan.
2) The following terms and conditions implement reasonable and prudent measure 2:
a) Reclamation shall prepare and implement a plan to assess the effectiveness of waterrelease ramping rates intended to minimize or avoid displacement and stranding of steelhead owing to winter-storm operations. This plan shall include, but not be limited to, (1) a description of the field-sampling and analytical methods that will be used for determining river depth-to-discharge relationships across the full wetted channel width over a range of discharges to assess the relative rate water depth declines and areas become dewatered or disconnected from flowing water (e.g., overflow channels), (2) a description of the field-sampling procedures for detecting and monitoring steelhead displacement and stranding during and after each winter-storm operations water-release, (3) a description of the procedures and mechanisms for real-time adjustments of waterreleases should steelhead stranding be observed or expected to occur, (4) the schedule for conducting elements of the effectiveness monitoring and reporting the findings to NMFS, and (5) a commitment to modify winter-storm operations water-release ramping rates as necessary and informed by the findings of the effectiveness monitoring. b) Reclamation shall submit a draft of the subject plan to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for our review no later than 120 days after the date of the final Cachuma Project biological opinion issued to 165
Reclamation. No later than 30 days following the date of NMFS’ letter commenting on the draft plan, Reclamation shall submit to NMFS (at the foregoing address) for review a final plan that addresses NMFS’ comments. Reclamation must receive our agreement for the subject plan prior to implementing the plan.
3) The following terms and conditions implement reasonable and prudent measure 3:
a) Reclamation shall be prepared to release water into Hilton Creek through alternative mechanisms (e.g., water-tank truck, onsite water-storage tanks, pumping water from the stilling basin) prior to conducting inspection, testing or maintenance of the Hilton Creek Water System that may cause water releases to be interrupted. b) Reclamation shall immediately release water into Hilton Creek through the alternative mechanisms identified in term and condition 3(a), or other mechanism proposed by Reclamation and accepted by NMFS, if water releases through the Hilton Creek Water System cease or are appreciably reduced. Reclamation shall release water at a rate and quantity sufficient to avoid stranding of steelhead, and of a quality similar to water in Hilton Creek at the time of water-release interruption. c) Reclamation shall monitor flow and water quality in Hilton Creek immediately prior and during inspection, testing or maintenance of the Hilton Creek Water System and implementation and effectiveness of term and condition 3(a) and 3(b). Reclamation shall report the findings of this monitoring annually to NMFS, unless as otherwise required by term and condition 5(a), below.
4) The following terms and conditions implement reasonable and prudent measure 4:
a) Reclamation shall capture and remove nonnative fish species from the Santa Ynez River Watershed throughout Reclamation’s property downstream of Bradbury Dam, and at locations outside of Reclamation’s property where access is granted, by one or more of the following methods as generally described in the proposed action (Bureau of Reclamation 2015i): spear fishing; gigging; dip-netting; seining; and electrofishing.
Seining and electrofishing shall only be conducted in areas where steelhead are not expected to be present or can effectively be avoided, such as distinct habitat areas (pools) or portions thereof. This action shall be conducted at least once per year or as otherwise informed by monitoring (e.g., bank and snorkeling observations) and coordination with NMFS.
b) Reclamation shall, within one year after issuance of this final biological opinion, temporarily dewater the Bradbury Dam stilling basin, completely or sufficiently, to remove all nonnative fish species therein to the maximum extent practicable. Dewatering of the stilling basin shall be conducted at a time or in a manner that avoids or minimizes effects to water quality (temperature and turbidity) in downstream habitats and does not interfere with downstream flow prescribed in this biological opinion. All methods of capture identified in term and condition 4(a) may be utilized; the aforementioned restrictions on seining and electrofishing do not apply to the stilling basin. c) Within the first dry season (e.g., June) following any spill events at Bradbury Dam, Reclamation shall temporarily dewater the stilling basin, completely or sufficiently, to remove all nonnative fish species therein to the maximum extent practicable. Dewatering of the stilling basin shall be conducted at a time or in a manner that avoids or minimizes 166
effects to water quality (temperature and turbidity) in downstream habitats and does not interfere with downstream flow targets prescribed in this biological opinion. All methods of capture identified in term and condition 4(a) may be utilized; the aforementioned restrictions on seining and electrofishing do not apply to the stilling basin. d) Reclamation shall monitor nonnative fish removal activities and report the findings annually to NMFS, unless as otherwise required by term and condition 5(a), below. 5) The following terms and conditions implement reasonable and prudent measure 5:
a) Reclamation shall prepare a critical drought operations plan prior to the end of two consecutive water-years (based on projections during the second water-year) each resulting in less than 15,366 ac-ft. of inflow to Cachuma Reservoir (i.e., dry or critically dry water-years) to minimize the amount of habitat temporarily lost and the number of steelhead harmed or killed should drought conditions continue and the reservoir decline to 665 ft. water-surface elevation. The plan shall include, but not be limited to, (1) a description of the mechanism or mechanisms that will be used to conduct water releases to Hilton Creek and the Santa Ynez River, (2) the water delivery rates and associated thresholds for adjusting proposed delivery rates, (3) the manner and extent the proposed rates affect the quantity and quality of habitat for steelhead, and (4) the specific processes and procedures for conducting rescue and relocation of steelhead that may be at risk of harm or death resulting from critical drought conditions and operations (e.g., coordination with appropriate resources agencies assisting Reclamation in rescue and relocation, identification of rescue and relocation sites informed by item 4, above), and monitoring effectiveness of the rescue and relocation.
b) Reclamation shall submit a draft of the subject plan to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) for our review no later than September 30 of the second consecutive dry or critically dry water-year. No later than 30 days following the date of NMFS’ letter commenting on the draft plan, or otherwise identified in NMFS’ comment letter, Reclamation shall submit to NMFS (at the foregoing address) for review a final plan that addresses NMFS’ comments.
Reclamation must receive our agreement for the subject plan prior to implementing the plan.
6) The following terms and conditions implement reasonable and prudent measure 6:
a) Reclamation shall contact NMFS (Anthony Spina, 562-980-4045, [email protected], or other staff as directed by NMFS) immediately if one or more steelhead are found dead, injured, or stranded or likely to become stranded. The purpose of the contact shall be to review the activity resulting in take to determine if and what additional protective measures may be required. Dead individuals shall be collected, measured, photographed, cataloged (multiple mortalities), individually sealed in a labeled (date and location of collection) freezer bag, and frozen until the carcass can be transferred to NMFS. The cause or suspected cause of death shall be reported to NMFS.
b) When a fish rescue is determined necessary and appropriate, Reclamation or its designee (e.g., California Department of Fish and Wildlife or Cachuma Operation and Maintenance Board fisheries staff or both) shall rescue and relocate steelhead that 167
become or are likely to become stranded in areas subject to desiccation resulting from foreseeable or unforeseeable circumstances, as identified in Reclamation’s Cachuma Project fish rescue plan (Bureau of Reclamation 2015k). Reclamation shall be responsible for ensuring adequate qualified staff is available for conducting steelhead rescue and relocations, including Reclamation staff, and not rely on availability of NMFS staff as indicated in Reclamation’s proposed fish-rescue plan. c) Reclamation shall submit a report of each steelhead rescue and relocation to NMFS’ California Coastal Office (501 W. Ocean Blvd., Suite 4200, Long Beach, California 90802) no later than 30 days following completion of the action; a compilation of steelhead rescue and relocation actions shall also be included in Reclamation’s annual Cachuma Project implementation and effectiveness monitoring report. In addition to the information outlined in the fish rescue plan (Bureau of Reclamation 2015k), individual steelhead rescue and relocation reports shall include a description of the activity or condition causing the need for steelhead rescue and relocation, and any recommendations that may be appropriate for modifying such activity or condition in the future.
2.10 Conservation Recommendations
Section 7(a)(1) of the ESA directs federal agencies to use their authorities to further the purposes of the ESA by carrying out conservation programs for the benefit of the threatened and endangered species. Specifically, conservation recommendations are suggestions regarding discretionary measures to minimize or avoid adverse effects of a proposed action on listed species or critical habitat or regarding the development of information (50 CFR 402.02). 1) We recommend Reclamation coordinate and collaborate with the California State Water Resources Control Board, U.S. Geological Survey, Santa Ynez River Water Conservation District, and Santa Ynez River water-users for the purposes of evaluating the existing condition and interaction between groundwater and surface water in the Santa Ynez River downstream of Bradbury Dam to the estuary, and then formulating and implementing water management actions to reduce temporal and spatial discontinuity of surface water in the Santa Ynez River. We believe the outcome of this effort will lend to increased efficiency and effectiveness of Bradbury Dam water-releases to maintain a functional freshwater migration corridor and freshwater rearing areas for endangered steelhead in the Santa Ynez River.
2) We recommend Reclamation coordinate and collaborate with the owners and operators of Gibraltar Dam (City of Santa Barbara), Mono debris basin (County of Santa Barbara), and Juncal Dam (Montecito Water District) for the purpose developing and then implementing solutions for providing steelhead passage at or around these structures in the upper Santa Ynez River Watershed as recommended in the Southern California Steelhead Recovery Plan (National Marine Fisheries Service 2012c).
2.11 Reinitiation of Consultation
This concludes formal consultation for the proposed operation and maintenance of the Cachuma Project. As 50 CFR 402.16 states, reinitiation of formal consultation is required where discretionary federal agency involvement or control over the action has been retained or is authorized by law and if: (1) the amount or extent of incidental taking specified in the incidental take statement is exceeded, (2) new information reveals effects of the agency action that may 168
affect listed species or critical habitat in a manner or to an extent not considered in this opinion, (3) the agency action is subsequently modified in a manner that causes an effect to the listed species or critical habitat that was not considered in this opinion, or (4) a new species is listed or critical habitat designated that may be affected by the action.
3.0 DATA QUALITY ACT REQUIREMENTS
The Data Quality Act (DQA) specifies three components contributing to the quality of a document. They are utility, integrity, and objectivity. This section of the opinion addresses these DQA components, documents compliance with the DQA, and certifies that this opinion has undergone pre-dissemination review.
3.1 Utility
Utility principally refers to ensuring that the information contained in this consultation is helpful, serviceable, and beneficial to the intended users. The intended users of this opinion are the Bureau of Reclamation. Other interested users could include the State Water Resources Control Board, Cachuma Operations and Maintenance Board, other local water agencies, and interested public. Individual copies of this opinion were provided to the Bureau of Reclamation. This opinion will be posted on the Public Consultation Tracking System web site (https://pcts.nmfs.noaa.gov/pcts-web/homepage.pcts ). The format and naming adheres to conventional standards for style.
3.2 Integrity
This consultation was completed on a computer system managed by NMFS in accordance with relevant information technology security policies and standards set out in Appendix III, ‘Security of Automated Information Resources,’ Office of Management and Budget Circular A-130; the Computer Security Act; and the Government Information Security Reform Act.
3.3 Objectivity
Information Product Category: Natural Resource Plan
Standards: This consultation and supporting documents are clear, concise, complete, and unbiased; and were developed using commonly accepted scientific research methods. They adhere to published standards including the NMFS ESA Consultation Handbook, ESA regulations, 50 CFR 402.01 et seq., and the MSA implementing regulations regarding EFH, 50 CFR 600.
Best Available Information: This consultation and supporting documents use the best available information, as referenced in the References section. The analyses in this opinion contain more background on information sources and quality.
Referencing: All supporting materials, information, data and analyses are properly referenced, consistent with standard scientific referencing style.
Review Process: This consultation was drafted by NMFS staff with training in ESA, and reviewed in accordance with West Coast Region ESA quality control and assurance processes. 169
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i
Annual Hydrograph Assessment for
Steelhead Migration in the Santa Ynez River
Prepared by:
Alison O’Dowd1, Bill Trush2,
David Colvin, Koa Lavery, Derek Ichien, and Omar Abi‐Chahine Humboldt State University River Institute
1. Principal Investigator, Department of Environmental Science & Management
2. Research Associate and Adjunct Professor, Department of Environmental Science & Management
Prepared for:
National Marine Fisheries Service
National Oceanic and Atmospheric Administration
June 30, 2014
ii
Table of Contents
List of Figures ............................................................................................................................ vi List of Tables ........................................................................................................................... xiii Executive Summary ..................................................................................................................... xiv 1 Introduction/Purpose Statement .............................................................................................. 1 2 Total Annual Precipitation Exceedence and Water Year Classification in the Santa Ynez River Basin...................................................................................................................................... 2
2.1 Santa Ynez River Regulatory Periods ............................................................................ 10
2.2 Santa Ynez River Annual Hydrographs: Then and Now ............................................... 10
2.3 Santa Cruz Creek: A Hydrologic Baseline Waiting to Happen ..................................... 15 3 Adult Steelhead Passage Opportunity Days in the Lower Santa Ynez River ....................... 19
3.1 Introduction .................................................................................................................... 19
3.2 Minimum Adult Steelhead Passage Depth ..................................................................... 20
3.3 Minimum Adult Steelhead Passage Streamflows: Applying the Thompson Method .... 21
3.4 Riffle Crest Thalwegs (RCTs) in the Lower Santa Ynez River: Estimating Riffle Depth as a Function of Daily Average Streamflow (Q) ...................................................................... 25
3.5 Adapting Riffle Crest Thalwegs to the Thompson Method for Estimating Minimum Adult Passage Streamflows ....................................................................................................... 27
3.6 Minimum Adult Passage Streamflows Using RCT-Q Rating Curves ........................... 31
3.7 Annual Adult Steelhead Passage Opportunity Days in the Lower Santa Ynez River ... 32
3.8 Conclusions .................................................................................................................... 39
3.9 Bradbury Dam Effects on Passing Floods...................................................................... 41 4 Spawning Opportunity and Upstream Migration Model ...................................................... 46
4.1 Introduction .................................................................................................................... 46
4.2 Estimating Steelhead Spawning Potential: Low Risk Spawning Days .......................... 47 iii
4.3 Estimating Steelhead Successful Spawning Opportunity Days ..................................... 48
4.4 A Tool for Measuring Steelhead Spawning Success: An Adult Steelhead Migration Model ………………………………………………………………………………………….49
4.4.1 Streamflow Estimation along the Adult Steelhead Migration Route ...................... 49
4.4.2 Estimation of Daily Average Migration Rates from Riffle Crest Thalweg (RCT) Depths along the Migration Route ........................................................................................ 52
4.4.3 Setting Maximum Allowable Travel Days ............................................................. 53
4.4.4 Modeling Steelhead Migration into Salsipuedes Creek Watershed ........................ 53
4.5 Assessing Low Risk Spawning Days and Successful Spawning Opportunity Days in Salsipuedes Creek Watershed ................................................................................................... 54
4.6 Annual Low Risk Spawning Day Findings .................................................................... 61
4.7 Annual Successful Spawning Opportunity Day Findings .............................................. 61
4.8 Assessing Potential Effects of Adult Steelhead Migration Delay on Successful Spawning Opportunity Days in Salsipuedes Creek .................................................................. 62
4.9 Sensitivity Analysis Modeled for Daily Average Migration Rate ................................. 69
4.10 Conclusions ................................................................................................................ 71 5 Steelhead Juvenile and Smolt Outmigration ......................................................................... 73
5.1 Introduction .................................................................................................................... 73
5.2 Spring and Summer Baseflows from San Lucas Bridge to Lompoc .............................. 73
5.3 Lompoc/San Lucas Bridge Summer Streamflow Ratio ................................................. 81
5.4 Channel Connectivity ..................................................................................................... 83
5.4.1 Introduction ............................................................................................................. 83
5.4.2 Juvenile Steelhead Minimum Passage Depth and Streamflow ............................... 83
5.4.3 Tributary and Mainstem Channel Connectivity ...................................................... 84 iv
5.4.4 Assessing Connectivity between Lower Salsipuedes Creek and the Mainstem Santa Ynez River near Lompoc ...................................................................................................... 85
5.5 A Lompoc Streamflow Seepage Threshold for a Dry ‘H’ Street Channelbed ............... 89
5.6 Preliminary Assessment of Juvenile Steelhead Growth in the Mainstem Lower Santa Ynez River and Its Importance to Recovery ............................................................................. 95
5.7 Estimating Improved Smolt Survival from Springtime Bradbury Dam Releases in the Lower Santa Ynez River Mainstem .......................................................................................... 97 6 Channel Hydraulics in the Lower Santa Ynez River and Its Importance to Steelhead Migration, Life History Needs, and Recovery ............................................................................ 100
6.1 Introduction .................................................................................................................. 100
6.2 Background .................................................................................................................. 101
6.3 Constructing RCT-Q Rating Curves for the Lower Santa Ynez River Mainstem Channel ………………………………………………………………………………………...104
6.4 Identifying Hydraulic Controls and Thresholds (QT) in Santa Ynez River RCT-Q Rating Curves ..................................................................................................................................... 107
6.5 Hydraulic Controls in Santa Ynez River RCT-Q Rating Curves ................................. 111
6.6 Influence of Hydraulic Controls on Steelhead Habitat ................................................ 116
6.7 Comparison of Solvang Mainstem Hydraulic Controls to DWR PHABSIM Study.... 118
6.8 Estimated Streamflow Ranges for Steelhead Life Stage Habitats ............................... 123 7 RECOMMENDATIONS .................................................................................................... 126 A Synthesis – “The Perfect Match” ........................................................................................ 126
7.1 Recommendation No. 1. Think and Manage by Cohort Years not by Individual Water Years 134
7.2 Adult Steelhead Migration Recommendation No. 2. Adult Steelhead Migration RealTime Bradbury Dam Releases ................................................................................................ 135
7.2.1 Introduction ........................................................................................................... 135 v
7.2.2 Proposed Real-Time Release Strategy .................................................................. 137
7.2.3 Simple Excel Spreadsheet Accounting ................................................................. 139
7.2.4 Findings................................................................................................................. 139
7.2.5 Evaluation Methodology ....................................................................................... 142
7.2.6 Multiple Purpose Real-time Bradbury Dam Releases .......................................... 143
7.2.7 Minimum Passage Streamflows are not Spawning Habitat Streamflows ............. 143
7.2.8 Minimum Passage Streamflows are not Migration Streamflows ......................... 144
7.2.9 Refinements/Observations .................................................................................... 146
7.3 Recommendation No. 3. Real-time Bradbury Dam Augmentation Releases for Annual Smolt and Juvenile Steelhead Outmigration ........................................................................... 147 References ................................................................................................................................... 156
vi
List of Figures
Figure 1. Santa Ynez River Basin with location of streamflow gages and selected tributaries.
Specific gage details provided in inset table. .................................................................................. 4 Figure 2. Santa Ynez River Basin with selected landmarks including tributaries, dams, and bridges. ............................................................................................................................................ 5 Figure 3. Lower Santa Ynez River watershed with selected features downstream of Bradbury Dam including cities, bridges, and tributaries. ............................................................................... 6 Figure 4. Exceedence values (% equal to or greater than) for total annual precipitation monitored at Santa Barbara County’s Flood Control District Station No. 230 at Gibraltar Dam from WY1920 to WY2012. The smaller the percentage in P, the greater the total annual precipitation. ........................................................................................................................................................ .7 Figure 5. ‘Historic’ annual hydrographs of the Santa Ynez River near Lompoc (USGS Gaging Station No. 11134000) from WY1908 to WY1918. ..................................................................... 12 Figure 6. ‘Contemporary’ annual hydrographs of the Santa Ynez River near Lompoc (USGS Gaging Station No. 11134000) from WY1990 to WY2012. ........................................................ 13 Figure 7. Selected photocopies of USGS streamflow measurements in the Santa Ynez River Basin in WY1914 and WY1915 reported in USGS Water Supply Paper No.721 as ‘Miscellaneous’ measurements. .................................................................................................... 18 Figure 8. An adult steelhead with scale references (from McBain&Trush and Trout Unlimited 2000). ............................................................................................................................................ 21 Figure 9. Application of the minimum passage depth to the 10% and 25% width criteria in the Thompson Method. ....................................................................................................................... 23 Figure 10. Example diagram showing how stream stage can be used to estimate Riffle Crest Thalweg (RCT) depths. The stage height at 0 cfs is subtracted from the stage height at 100 cfs to determine the RCT depth at 100 cfs. ............................................................................................ 26 Figure 11. RCT-Q rating curve constructed from USGS Gaging Station No. 11128500 Santa Ynez River at Solvang Q-Stage rating curve. ................................................................................ 29 vii
Figure 12. RCT-Q rating curve constructed from USGS Gaging Station No. 11134000 Santa Ynez River at Santa Ynez River at ‘H’ Street nr Lompoc Q-Stage rating curve. .......................... 30 Figure 13. RCT-Q rating curve constructed from USGS Gaging Station No. 1113300 Santa Ynez River at Narrows nr Lompoc Q-Stage rating curve. ..................................................................... 30 Figure 14. Annual Adult Steelhead Passage Opportunity Days in the Lompoc Floodplain during the Pre-Gibraltar Dam Period by water year with lower bound line. ........................................... 33 Figure 15. Adult Steelhead passage Opportunity Days in the Lompoc Floodplain during the Gibraltar Dam Period by water year with lower bound line. ........................................................ 34 Figure 16. Adult Steelhead Passage Opportunity Days in the Lompoc Floodplain by water year during the Cachuma/Bradbury Dam Period with lower bound line. ............................................ 34 Figure 17. Adult Steelhead Passage Opportunity Days at Solvang for estimated unimpaired annual hydrographs from WY1942 to WY2012 with lower bound line. ..................................... 35 Figure 18. Adult Steelhead Passage Opportunity Days at Solvang by water year during the Gibraltar Dam Period with lower bound line. ............................................................................... 35 Figure 19. Adult Steelhead Passage Opportunity Days at Solvang by water year during the Cachuma/Bradbury Dam Period with lower bound line. .............................................................. 36 Figure 20. Lower bound lines for Adult Steelhead Passage Opportunity Days in the Lompoc Floodplain during the Pre-Gibraltar Dam, Gibraltar Dam, and Cachuma/Bradbury Dam periods. ....................................................................................................................................................... 38 Figure 21. Lower bound lines for Adult Steelhead Passage Opportunity Days at Solvang during the Gibraltar Dam and Cachuma/Bradbury Dam periods, and for estimated unimpaired WY1942 to WY2011 annual hydrographs. .................................................................................................. 38 Figure 22. Adult steelhead passage opportunity losses of the lower bound line at Solvang during each regulatory period................................................................................................................... 40 Figure 23. Adult steelhead passage opportunity losses of the lower bound line at Lompoc during each regulatory period................................................................................................................... 40 viii
Figure 24. Flood peaks (instantaneous peak cfs) at USGS Gaging Station No. 11124500 Santa Cruz Creek nr Santa Ynez (DA = 74 mi2
) that were spilled, and not spilled, at Bradbury Dam
during the Contemporary Bradbury Dam Period. ......................................................................... 42 Figure 25. Rainfall/runoff hydrographs at USGS Gaging Station No.11128500 Santa Ynez River at Solvang that occurred December 18 to 26, 2002 modeled for three flow scenarios: (1) with Bradbury Dam, (2) with Gibraltar Dam, and (3) without Gibraltar and Bradbury dams. ............ 44 Figure 26. Rainfall/runoff hydrographs at Solvang that occurred March 14 to April 19, 2002 modeled for three flow scenarios: (1) with Bradbury Dam, (2) with Gibraltar Dam, and (3) without Gibraltar and Bradbury dams........................................................................................... 45 Figure 27. River miles and watershed area for segments and spawning destinations used in migration model. ........................................................................................................................... 47 Figure 28. Flow chart of Adult Steelhead Migration and Spawning Model with major subroutines and their purposes. ........................................................................................................................ 51 Figure 29. Relationship of daily average migration rate (miles/day) to the RCT depth (ft) used for migration routing from the Santa Ynez Lagoon to the spawning destinations in Salsipuedes Creek watershed. ........................................................................................................................... 53 Figure 30. Low Risk Spawning (LRS) days (red triangles) and Spawning Success Opportunity (SSO) days (blue squares) modeled for Lower Salsipuedes Creek (WY1942 to WY2012). ....... 55 Figure 31. Low Risk Spawning (LRS) days (red triangles) and Spawning Success Opportunity (SSO) days (blue squares) modeled for El Jaro Creek (WY1942 to WY2012). .......................... 56 Figure 32. Low Risk Spawning (LRS) days (red triangles) and Spawning Success Opportunity (SSO) days (blue squares) modeled for Los Amoles Creek (WY1942 to WY2012). .................. 57 Figure 33. Low Risk Spawning (LRS) days (red triangles) and Spawning Success Opportunity (SSO) days (blue squares) modeled for Lower Salsipuedes Creek vs precipitation exceedence (WY1942 to WY2012). ................................................................................................................ 58 Figure 34. Low Risk Spawning (LRS) days (red triangles) and Spawning Success Opportunity (SSO) days (blue squares) modeled for El Jaro Creek vs precipitation exceedence (WY1942 to WY2012)....................................................................................................................................... 59 ix
Figure 35. Low Risk Spawning (LRS) days (red triangles) and Spawning Success Opportunity (SSO) days (blue squares) modeled for Los Amoles Creek vs precipitation exceedence (WY1942 to WY2012). ................................................................................................................................. 60 Figure 36. Hydrograph of Lower Salsipuedes Creek (WY2008). ................................................ 64 Figure 37. WY 2008 hydrograph converted to Riffle Crest Thalweg Depth with an adult steelhead for size scale. ................................................................................................................. 66 Figure 38. The WY2008 hydrograph converted to daily RCT depths at each spawning destination. Streambed and adult steelhead drawing included for scale comparison. .................. 66 Figure 39. River miles from the mouth of Salsipuedes Creek to the El Jaro Creek spawning destination vs. date for WY2008. The green lines show daily accrued miles for a migrating steelhead from the mouth of Salsipuedes Creek. Steep lines represent fast migration; flat portions reveal when the streamflow was too low for upward migration. Successful Spawning Opportunity (SSO) days are labeled with blue diamonds. ............................................................ 67 Figure 40. Hydrograph of individually separated storms on Lower Salsipuedes Creek in WY2008. ....................................................................................................................................... 68 Figure 41. River miles from the mouth of Salsipuedes Creek to the El Jaro Creek spawning destination vs. day isolating each storm event in WY2008. The green lines show daily accrued miles for a migrating steelhead from the mouth of Salsipuedes Creek. Green lines, that do not reach RM 25.6, did not reach the spawning destination within the maximum travel time. LRS days are shown as blue diamonds. ................................................................................................ 68 Figure 42. Ratio of Total Annual Successful Spawning Opportunity (SSO) Day / Total Annual Low Risk Spawning (LRS) Days by Total Annual Precipitation Exceedence using baseline daily average migration rates for WY1942 to the present. .................................................................... 70 Figure 43. Ratio of Total Annual Successful Spawning Opportunity (SSO) Day / Total Annual Low Risk Spawning (LRS) Days by Total Annual Precipitation Exceedence using daily average migration rates 25% greater than baseline rates for WY1942 to the present. ............................... 70 x
Figure 44. Ratio of Total Annual Successful Spawning Opportunity Days / Total Annual Low Risk Spawning Days by Total Annual Precipitation Exceedence (P, %) using daily average migrations rates 25% less than baseline rates for WY1942 to the present. .................................. 71 Figure 45. Pre-Gibraltar Dam mid-June summer baseflow at Lompoc and San Lucas Bridge. ... 75 Figure 46. Pre-Gibraltar Dam mid-July summer baseflow at Lompoc and San Lucas Bridge. ... 76 Figure 47. Pre-Gibraltar mid-August summer baseflow at Lompoc and San Lucas Bridge. ....... 77 Figure 48. Upper and lower bound lines for June 15 summer baseflows near Lompoc during the Gibraltar Dam Period. ................................................................................................................... 79 Figure 49. Upper and lower bound lines for June 15 summer baseflows near Lompoc during the Bradbury Dam Period. .................................................................................................................. 79 Figure 50. Comparison of lower bound lines for mid-June summer baseflows during PreGibraltar Dam Period, Gibraltar Dam Period, and Bradbury Dam Period. .................................. 80 Figure 51. Ratio of daily average streamflows, Q Lompoc/Q SanLucasBridge, during late-spring and summer for pre-Gibraltar Dam annual hydrographs. ............................................................. 82 Figure 52. Connectivity line for QMinConnect in Lower Salsipuedes Creek (Yaxis) and QMinConnect for the mainstem Santa Ynez River at ‘H’ Street. ................................................. 87 Figure 53. Threshold streamflow at either Lompoc USGS gaging stations (depending on water year: ‘at Narrows nr Lompoc’ or ‘nr Lompoc’) on same day downstream USGS Gaging Station No. 11134000 Santa Ynez River at ‘H’ Street nr Lompoc first reported a 0 cfs daily average streamflow..................................................................................................................................... 90 Figure 54. Parallel recession limbs of daily average streamflows at ‘H’ Street and at the Narrows from May 31, 2000 to June 16, 2000. ........................................................................................... 91 Figure 55. Parallel recession limbs of daily average streamflows at ‘H’ Street and at the Narrows from May 7 to May 27, 1962. ....................................................................................................... 91 Figure 56. Annual hydrographs from WY1990’s and WY2000’s at Lompoc for spring and summer baseflows. ........................................................................................................................ 93 Figure 57. Smolt-to-Adult Return Curve from McBain and Trush (2012, p.11)………………98 xi
Figure 58. Primary hydraulic controls for a generalized stage-Q rating curve…………………103 Figure 59. Station rating table reproduced from USGS Water Supply Papers No. 177 for WY1905…………………………………………………………………………………..…….105
Figure 60. USGS Stage-Q Rating Curve for ‘nr Lompoc’ gaging station in WY1967……...…106 Figure 61. USGS Stage-Q Rating Curve for ‘nr Lompoc’ gaging station in WY1969……...…107 Figure 62. Straight-line segments fit to contemporary ‘H’ Street RCT rating curve………..…109 Figure 63. Scan of Solvang RCT-Q Rating Curve Worksheet for Identifying Hydraulic Breakpoints. (Xaxis = Q (cfs) and Yaxis=RCT Depth (ft) (Note dual axes)………….………110 Figure 64. Scan of ‘H’ Street RCT-Q Rating Curve Worksheet for Identifying Hydraulic Breakpoints (Xaxis = Q (cfs) and Yaxis=RCT Depth (ft) (Note dual axes)……………..…….111 Figures 65A and B. Contemporary ‘H’ Street (A) and Solvang (B) RCT-Q Rating Curve with Hydraulic Controls and Threshold (QT’s)…………………………………...…………….……113 Figure 66. SYRTAC (1999) thalweg velocities as a function of streamflows up to 50 cfs in three mainstem study reaches of Lower Santa Ynez River from Solvang upstream…………….…..115 Figure 67. PHABSIM WUA rating curves for steelhead fry refuge/rearing, juvenile rearing, and adult spawning with superimposed hydraulic controls from the contemporary Solvang RCT-Q rating curve………………………………………………………………………………..……120
Figure 68. Expected range of streamflows for each steelhead life stage’s physical habitat needs at Solvang and ‘H’ Street in relation to hydraulic thresholds……………………………….…….124 Figure 69. Expected range of streamflows for each steelhead life stage’s physical habitat needs at ‘H’ Street (Lompoc Floodplain) in relation to hydraulic thresholds……………………...……125 Figure 70. An adult steelhead’s size contrasted with daily average riffle crest thalweg depth using estimated annual hydrographs at San Lucas Bridge converted into annual riffle depth-ographs from WY1942 to the present. Water year types are coded by color…………...………131 Figure 71. Annual total ac-ft real-time Bradbury Dam releases for adult migration and mainstem spawning from WY1990 through WY2012……………………………………………………140 xii
Figure 72. RCT-Q rating curve for Salsipuedes Creek with hydraulic controls and their streamflow thresholds.……………………………………………………………………….…148
Figure 73. Provisional USGS hydrograph from February 22 to March 22 at USGS Gaging Sta.
No. 11132500 Salsipuedes Creek nr Lompoc………………………………………………….152 Figure 74. Provisional USGS hydrograph from February 26 to March 24, 2014 at USGS Gaging Sta. No. 11133000 Santa Ynez River at Narrows nr Lompoc………………………………….153 Figure 75. Provisional USGS hydrograph from February 22 to March 22 at USGS Gaging Sta.
No. 11134000 ‘H’ Street nr Lompoc………………………………………………………….154 Figure 76. Provisional USGS hydrograph from March 22 to May 24, 2014 at USGS Gaging Sta.
No. 11133000 Santa Ynez River at Narrows nr Lompoc………………………………………155
xiii
List of Tables
Table 1. Exceedence values (P) for total annual precipitation measured at Santa Barbara County’s Flood Control District Station No. 230 at Gibraltar Dam from WY1920 through WY2012, presented chronologically. Additional total annual precipitation estimates for WY1900 through WY 1919 were assigned exceedence values estimated from the Gibraltar Dam exceedence curve. ........................................................................................................................... 8 Table 2. Low Risk Spawning (LRS) day parameters. Each spawning destination used a maximum incubation period of 40 days........................................................................................ 48 Table 3. Minimum connecting comparison among WYs during Contemporary Bradbury Dam Period. ........................................................................................................................................... 86 Table 4. Lengths of juvenile steelhead using a 0.2% per day constant growth rate………..……96 Table 5. Lengths of juvenile steelhead using a 0.3% per day constant growth rate……….…….96 Table 6. Lengths of juvenile steelhead using a 0.5% per day constant growth rate………..……97 Table 7. Last day in recession hydrograph when the daily average streamflow was greater than, or equal to, the minimum juvenile passage streamflow for Salsipuedes Creek (QJuvMinPass = 4.0 cfs)(Figure 72) and Santa Ynez River at ‘H’ Street nr Lompoc (QJuvMinPass = 7.0 cfs)(Figure 56A)……………………………………………………………………………………...……..149
xiv
Executive Summary
The Santa Ynez River was a perfect match for Southern California steelhead. This perfect match was made possible because the Santa Ynez River (SYR) Basin encompassed a drainage area of approximately 900 mi2
. A big basin can provide sufficient magnitude, duration, and frequency of daily streamflows to reliably meet all life history needs a steelhead population geographically situated close to its southern limit requires. With basin size acting as a highly effective buffer to climatic uncertainties and extremes (e.g., extended drought periods), steelhead responded by creating possibly the largest annual adult run in Southern California.
Large volumes of winter and early-spring water flowing under San Lucas Bridge, the gateway between upper and lower SYR Basin, were stored in annually rechargeable groundwater aquifers. In spring or early-summer, depending on the water year (i.e., Wet or Dry), the Santa Ynez River above San Lucas Bridge began naturally drying-up. But below San Lucas Bridge, the mainstem continued to receive high baseflows sustained by groundwater accretion from the rechargeable aquifers. From Solvang to the SYR Lagoon, the SYR mainstem was a highly dependable biologically productive hotspot that provided outmigrating smolts and juveniles a continuous migration route offering abundant, diverse, and productive juvenile rearing habitat in an otherwise arid environment. Although perfect, the match was vulnerable.
Surface flow and groundwater diversions already were underway in the SYR Basin by the turn of the twentieth century. However, a dry mainstem SYR channel at Lompoc in mid-August was still a rarity before the 1920’s. Big and small floods were still uncontrolled. In all but the driest water years, adult steelhead could readily access the upper SYR Basin to spawn. Beginning in 1920, an operational Gibraltar Dam blocked adult steelhead migration into SYR Basin’s mountainous upper 215 mi2
. The goal of every annual steelhead migration run, the collective mindset from each adult’s unswerving drive to spawn, is to blanket as much of the watershed as possible (depending on the water year) with fertilized eggs. In the 1930’s through late-1940s, adults still accomplished this feat … excluding the SYR Basin above Gibraltar Dam. CDFG’s biologist Leo Shapovalov documented rescuing millions of steelhead fry. CDFG (now CDFW) considered rescue necessary because spring recession streamflows were being stored/diverted at Gibraltar Dam. Meanwhile, groundwater pumping below San Lucas Bridge continued accelerating. xv
Following an extended drought in the late-1940s and early-1950s, Bradbury Dam sited just upstream of San Lucas Bridge began operations. Adult steelhead were now blocked from most of their spawning habitats, as was the annual gravel supply to many spawning habitats remaining below Bradbury Dam. More ominously, with respect to future prospects for meaningful population improvement, the once dependable volume of annual spring through mid-summer mainstem baseflows below San Lucas Bridge was disappearing by the 1980s.
Present-day management primarily relies on tributaries below Bradbury Dam to sustain streamflows in the SYR mainstem to meet smolt and juvenile steelhead migration instream flow needs. Our report concludes greater real-time management of Bradbury Dam releases will be necessary, particularly for improving downstream smolt and juvenile steelhead migration.
Salsipuedes Creek is the tributary watershed below Bradbury Dam with the greatest runoff and potential for rearing juvenile steelhead. It should be considered a litmus test for how future management actions perform. Rather than WYs, anadromous steelhead should be managed as Cohort Years (Recommendation No.1). A Cohort Year (CY) would begin on SYR Lagoon’s opening day (signaling the start of the annual adult steelhead run) and end the following calendar year when spring recession streamflows no longer allow 1-year old smolts to reach SYR Lagoon.
Storm events generated entirely below Bradbury Dam are capable of breaching SYR Lagoon to open the adult steelhead migration season. Following the first breach of the winter migration season, there is an inevitable 2 to 4 day adult delay in swimming 20 miles to the confluence of the closest major tributary: Salsipuedes Creek. Early-arriving adults can spawn in Lower Salsipuedes Creek or continue farther upstream. Later-arriving adults can stage at the confluence anticipating the next storm event, even a minor one. The first few days of the next storm hydrograph will offer deeper streamflows to migrate farther into small, upper tributaries and then spawn (e.g., Los Amoles Creek within the Salsipuedes Creek Watershed). In this manner, steelhead can saturate entire watersheds with as many fertilized eggs as possible even though the migration window is often brief.
Most of the Basin’s historic anadromous steelhead spawning habitat has been eliminated by dams. Adult steelhead entry into SYR Lagoon, followed by timely access to tributaries downstream of Bradbury Dam, must be accommodated in Extremely Wet through Below xvi
Normal water years. Mainstem streamflows greater than those contributed only by tributary watersheds below Bradbury Dam will be necessary to improve adult access to headwater spawning habitats. Since the late-1950s, Lake Cachuma Reservoir has captured 75% of all peak flood flows originating upstream of San Lucas Bridge. Passage opportunity days for adult steelhead migrating up the mainstem channel have been reduced over 80% in Above Normal water years. Real-time Bradbury Dam releases of 100 cfs during the adult steelhead migration season can be triggered by streamflow thresholds in unregulated Santa Cruz Creek (entering Lake Cachuma Reservoir) to improve annual adult steelhead migration (Recommendation No.2).
A great spawning year can produce abundant 1-year old smolts the following spring only if recession streamflows that following spring are sufficient. When smolts and yearling/juvenile steelhead leave Salsipuedes Creek, primarily March through early-May, the Santa Ynez River must promote rapid growth to SYR Lagoon in the weeks following their entry into the mainstem channel. Larger smolts and juveniles, benefiting from additional rapid growth in the mainstem and then in SYR Lagoon, will be essential to improving smolt return as spawning adults and building annual adult runs. An important bottleneck to downstream migration has been mounting near Lompoc since the 1920s: when streamflow recedes to 11 cfs above Robinson Bridge today, the streamflow 5 miles downstream at the USGS ‘H’ Street gaging station near Lompoc drops to 0 cfs. Juvenile and smolt outmigration from Lower Salsipuedes Creek downstream to the SYR Lagoon has been jeopardized or eliminated in 12 of the last 14 water years.
Recommendation No. 3 provides a framework for real-time Bradbury Dam releases that would re-connect the SYR mainstem migration route through to SYR Lagoon. Salsipuedes Creek annual hydrographs would be used as a real-time trigger for beginning these releases. The duration, frequency, and timing of minimum riverflow releases, achieving 38 cfs and 7 cfs at the USGS ‘H’ Street gage, would be determined by real-time streamflow triggers from daily streamflows at the USGS Santa Cruz Creek gage.
1 1 Introduction/Purpose Statement
The National Oceanic and Atmospheric Administration’s (NOAA) National Marine Fisheries Service (NMFS) has been evaluating how water storage activities in the Santa Ynez River of Southern California have affected endangered steelhead (Oncorhynchus mykiss) (NMFS 2000).
One steelhead life-history need that has been affected by water storage and diversion is adult and juvenile migration. Each water year’s annual hydrograph challenges migrating steelhead with a unique combination of changes to the magnitude, duration, frequency, and timing of daily average streamflows (Q). Dam operations/diversions and groundwater pumping have been altering annual hydrographs in the mainstem Santa Ynez River since the early-1900s. The challenge in this study was to evaluate the significance of hydrologic change, manifested in altered contemporary annual hydrographs, by understanding how steelhead migration once depended on historic annual hydrographs. Our study evaluated how changes to the river’s annual hydrographs affected successful adult and juvenile steelhead migration within the Santa Ynez River (SYR) and recommends remedial measures.
Historically, the collective goal of each adult steelhead cohort returning to spawn was to blanket the SYR Basin with millions of emerging young-of-the-year (YOY) as Shapovalov (1944) observed in the early-1940s. Each annual hydrograph either helps or hinders this goal. Wet water years producing annual hydrographs with multiple overlapping floods would allow adults to migrate far into the Basin’s mountainous headwaters. In contrast, Dry years producing only one or two widely-spaced (in time) small peak flow events might constrain adults to the mainstem channel and a few larger tributaries. Success at blanketing the basin with YOYs, therefore, can be a quantifiable metric by which to evaluate hydrologic change.
This report was organized as follows: (1) Provide an overview of past and present annual hydrographs while assigning an exceedence probability and regulatory period to each water year investigated, (2) Measure changes in annual adult steelhead passage opportunities in the Lower Santa Ynez River as a function of water year exceedence and regulatory period, (3) Model potential steelhead adult migration success in the most important tributary below Bradbury Dam (Salsipuedes Creek), (4) Evaluate changes in summer baseflows in the mainstem SYR below Bradbury Dam by regulatory period, and (5) Quantify juvenile passage and migration streamflow 2 thresholds in the mainstem SYR and Salsipuedes Creek. The report concludes with a synthesis and recommendations.
2 Total Annual Precipitation Exceedence and Water Year Classification in the Santa Ynez River Basin
Our analysis of adult steelhead upstream migration and juvenile steelhead downstream migration needed a simple, but quantitative, measure for the SYR Basin’s wide range in total annual rainfall and/or runoff. This measure would become an important independent physical variable by which to assess steelhead migration under changing water diversion scenarios and water year types (e.g., a ‘Wet’ year in contrast to a ‘Dry’ year). It would also serve as a simple proxy for the individual annual hydrographs upon which our analyses depended. Annual hydrographs with many runoff events throughout the winter, and extended spring baseflows persisting into summer, were expected to offer more adult migration opportunities and a higher quality juvenile out-migration environment. Annual hydrographs with these advantages should occur in water years with higher total runoff (measured in annual acre-ft). Although the SYR Basin’s streamflows have been monitored extensively by the USGS and others, the growing complexity in surface water diversions and expanding groundwater pumping from the early-1900s up to the present made estimating total annual runoff in the SYR Basin a challenging and complicated process. Rather than total annual runoff as the independent variable, we relied on total annual precipitation as our simple, quantitative proxy for individual annual hydrographs. Results from our adult and juvenile migration analyses, based on the exceedence probability of individual annual hydrographs (P), could then be presented graphically.
Of several precipitation stations in the SYR Basin, Santa Barbara County’s Flood Control District Station No. 230 at Gibraltar Dam had an extensive record (WY1920 to WY2012) and was centrally located within the SYR Basin (Figure 1, Figure 2, and Figure 3). Total annual precipitation (provided as water years) for each WY was ranked and then reported as an exceedence value (P) (Figure 4 and Table 1). The smaller the percentage in P, the greater the annual precipitation total. For example, WY2011 had a high total annual precipitation (from October 1, 2010 through September 31, 2011) of 39.03 inches with an assigned annual 3 exceedence probability (P) of 16.1% (Table 1). Therefore only 16.1% of the WYs between WY1920 and WY2012 had an annual precipitation total equal to, or greater than, 39.03 inches.
At only 13.50 inches of total annual precipitation, WY2012’s low annual precipitation total was equaled or exceeded by 91.4% of the WYs between WY1920 and WY2012 (Table 1). Therefore, WY2012’s exceedence value was P = 91.4%. WY2013 had the lowest annual precipitation (8.50 inches) on record at Gibraltor Dam.
Figure 1. Santa Ynez River Basin with location of streamflow gages and selected tributaries. Specific gage details provided in inset table. 4 Figure 2. Santa Ynez River Basin with selected landmarks including tributaries, dams, and bridges. 5 Figure 3. Lower Santa Ynez River watershed with selected features downstream of Bradbury Dam including cities, bridges, and tributaries. 6 .
F
S
igure 4. Exceede
tation No. 230 at
nce values (% eq
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Gibraltar Dam fr
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rom WY1920 to
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Y2012. The sma
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8 Table 1. Exceedence values (P) for total annual precipitation measured at Santa Barbara County’s Flood Control District Station No. 230 at Gibraltar Dam from WY1920 through WY2013, presented chronologically. Additional total annual precipitation estimates for WY1900 through WY1919 were assigned exceedence values estimated from the Gibraltar Dam exceedence curve.
WY
Total Annual
Precipitation
(inches)
Exceedence
(%) WY
Total Annual
Precipitation
(inches)
Exceedence
(%) WY
Total Annual
Precipitation
(inches)
Exceedence
(%)
1900 est 18.70 66.1 1938 41.3 12.9 1976 19.42 64.5
1901 est 23.14 47.0 1939 20.76 57.0 1977 15.66 81.7
1902 est 20.85 54.8 1940 18.13 68.8 1978 59.88 5.4
1903 est 31.25 29.0 1941 66.71 3.2 1979 28.11 35.5
1904 est 17.13 74.1 1942 18.95 65.6 1980 35.11 22.6
1905 est 45.23 12.9 1943 37.49 19.4 1981 21.93 50.5
1906 est 34.07 24.1 1944 29.41 33.3 1982 24.53 43.0
1907 est 42.10 12.0 1945 21.07 53.8 1983 63.88 4.3
1908 est 28.77 35.0 1946 25.28 39.8 1984 18.31 67.7
1909 est 55.54 7.2 1947 16.1 80.6 1985 16.8 77.4
1910 est 29.49 33.4 1948 12.39 92.5 1986 31.24 29.0
1911 est 48.66 10.6 1949 15.09 84.9 1987 11.39 95.7
1912 est 24.37 43.9 1950 16.84 76.3 1988 24.85 41.9
1913 est 18.33 67.8 1951 11.07 96.8 1989 14.89 88.2
1914 est 47.85 10.4 1952 49.43 10.8 1990 11.59 94.6
1915 est 31.97 28.2 1953 16.38 79.6 1991 30 30.1
1916 est 39.58 15.2 1954 20.54 58.1 1992 38.23 18.3
1917 est 33.65 23.8 1955 21.52 52.7 1993 49.61 9.7
1918 est 33.51 23.7 1956 23.82 45.2 1994 20.87 54.8
1919 est 20.18 59.5 1957 18.85 66.7 1995 58.83 6.5
1920 20.81 55.9 1958 52.69 8.6 1996 19.86 61.3
1921 22.61 47.3 1959 17.16 74.2 1997 24.46 44.1
1922 41.46 11.8 1960 14.97 86.0 1998 73.58 1.1
1923 22.36 49.5 1961 12.1 93.5 1999 16.92 75.3
1924 10.4 98.9 1962 36.14 21.5 2000 33.18 25.8
1925 17.41 71.0 1963 20.04 60.2 2001 40.93 14.0
1926 27.14 38.7 1964 14.78 89.2 2002 10.46 97.8
1927 28.26 34.4 1965 22.76 46.2 2003 27.62 37.6
1928 20.07 59.1 1966 29.7 32.3 2004 14.74 90.3
1929 19.65 63.4 1967 39.31 15.1 2005 69.25 2.2
1930 18.02 69.9 1968 14.93 87.1 2006 32.31 26.9
1931 17.34 73.1 1969 58.37 7.5 2007 10.03 100.0
1932 33.28 24.7 1970 17.39 72.0 2008 31.65 28.0
1933 16.43 78.5 1971 22.48 48.4 2009 15.27 83.9
1934 19.72 62.4 1972 15.62 82.8 2010 33.44 23.7
1935 29.7 31.2 1973 38.25 17.2 2011 39.03 16.1
1936 21.63 51.6 1974 25.25 40.9 2012 13.5 91.4
1937 36.14 20.4 1975 27.63 36.6 2013 8.50 100
9 WY types were classified from Figure 4 based on subtle breaks in the annual exceedence curve, as follows: Extremely Wet (P < 10%), Wet (P > 10% and < 30%), Above Normal (P > 30% and < 50%), Below Normal (P > 50% < 70%), Dry (P > 70% and < 90%), and Critically Dry (P > 90%). Note that the average annual precipitation total of 26.94 inches had an annual exceedence of P = 38.4%, making it an Above Normal WY. A total annual precipitation of 22.15 inches was our measure for ‘Normal’, with half the annual precipitation totals above and the other half below this median exceedence value of P = 50% (Figure 4). WY1923 (22.36 inches at P =
49.5%) and WY1981 (21.93 inches at P = 50.5%) were the two WY’s closest to the median (Figure 4).
Gibraltar Dam’s precipitation record began in WY1920, but USGS gaging stations were recording daily average streamflows earlier. The longest nearby precipitation record was at the County’s Santa Barbara Downtown County Building Station No. 234 dating back to WY1868. A linear regression of total annual precipitation between the Gibraltar Dam and Santa Barbara stations was developed to estimate total annual precipitation at Gibraltar Dam for WY1900 through WY1919. With these estimated annual precipitation totals, WY1900 through WY1919 were assigned exceedence (P) values from Figure 4. Water years from WY1900 to WY2012 were ranked chronologically with the P values for WY1900 through WY1919 highlighted as estimated (Table 1).
The exceedence curve in Figure 4 transitions from relatively steep to relatively flat between P = 40% and P = 45% and could serve as an overall management target for steelhead migration (i.e., maintain better spawning opportunities in WY’s with P < 45%, roughly the Above Normal and wetter WY’s). We expected a greater drop in total annual precipitation on the dry end of the annual exceedence curve and a less steep upward transition between Wet and Extremely Wet WY’s on the wet end (Figure 4). Most of the steep, wet end (from 30 inches to greater than 70 inches) could be attributed to a single large storm event in a given year that produced extended, higher recession streamflows ideal for adult steelhead migration into SYR’s headwaters. On the dry end (from 15 to 10 inches), most annual precipitation was associated with one or two rainfall events (though small and brief). These events would promote migration up and spawning within the mainstem SYR channel provided the SYR Lagoon had been breached. In some years, these 10 small and brief events in March and April were instrumental in providing downstream juvenile/smolt migration.
2.1 Santa Ynez River Regulatory Periods
The Santa Ynez River Basin has an extensive history of water use. Our report does not summarize this history. For background information regarding Basin history/geography, dam operations, past and present steelhead population status, and recent monitoring/restoration activities, refer to sources such as Alagona et al. (2012), Cachuma Operation and Maintenance Board (2008, 2012), and NMFS (2000).
Since the early-1900s, the Santa Ynez River steelhead population has been affected by two major dam projects and accelerated groundwater pumping. The Pre-Gibraltar Dam Regulatory Period, encompassing WY1900 through WY1918, precedes Gibraltar Dam operations, although extensive small diversions were already happening. The Gibraltar Dam Regulatory Period begins with an operational Gibraltar Dam and Reservoir (Figure 2) in WY1920, includes Jameson Lake and Juncal Dam becoming operational upstream of Gibraltar Dam in WY1930, and ends with the new Cachuma Reservoir in WY1953. The Cachuma/Bradbury Dam Regulatory Period begins in WY1954, but Cachuma Reservoir did not fill until April WY1958, then continues through the 1970s with the renaming of Cachuma Dam to Bradbury Dam, and ends in WY1999. The Contemporary Bradbury Dam Regulatory Period (WY2000 to the Present) ushers-in the 21st Century, but also has considerable operational project modifications.
2.2 Santa Ynez River Annual Hydrographs: Then and Now
The USGS and City of Santa Barbara gaged two primary mainstem Santa Ynez River locations prior to Gibraltar Dam (WY1920): (1) near Lompoc (upstream of Robinson Bridge) close to the Lower SYR mouth (RM 10.2) (DA = 790 mi2
) and (2) at the proposed Gibraltar Dam site (RM
73.5) (DA = 219 mi2
) in the Basin’s headwaters (Figure 2). Beginning WY1908, both stations provided daily average streamflows or at least daily gage heights. Although incomplete, these streamflow measurements provided good approximations of unimpaired annual hydrographs. But as early as WY1906, USGS hydrographers noted (USGS Water Supply Paper No. 213) that water rights had already exceeded mainstem baseflows in the Lower Santa Ynez River. As noted 11 in USGS Water Supply Paper No. 461: “The City of Santa Barbara diverts water at gage [SYR nr Santa Barbara, the proposed Gibraltar Dam Site] for municipal use. The record includes this diversion. Practically all water in river was being diverted from July 14 to September 30 [WY1917].” Pre-Gibraltar Dam annual hydrographs, therefore, were likely noticeably depleted by groundwater pumping and small surface diversions during spring through early-fall baseflows.
Plotting many annual hydrographs onto a single plot provided an intuitive perspective on what streamflows were like in the Santa Ynez River watershed before major dams, surface diversions, and extensive groundwater pumping. These ‘spaghetti’ graphs intentionally highlighted the variability of daily average streamflows from one WY’s annual hydrograph to the next.
Two spaghetti plots of annual hydrographs near Lompoc, between WY1908 to WY1918 (Figure 5) and WY1990 to WY2012 (Figure 6), provided quantitative, pre-dam ‘Historic’ and post-dam ‘Contemporary’ perspectives, respectively. Each water year was color-coded by water year type (Figure 5 and Figure 6). A maximum daily average streamflow (Q) of 500 cfs on the Y-axis gave sufficient resolution for summer baseflows without losing resolution for storm and storm recession streamflows. WY1908 through WY1918 provided a more ‘Wet’ perspective on natural unimpaired SYR ‘annual hydrographs’ (Figure 5); P values revealed more Wet than Dry years.
Even with surface/groundwater diversions, a prominent flow feature in Pre-Gibraltar Dam annual hydrographs was substantial streamflow throughout the summer at Lompoc. In WY1913 with its P = 67.8% bordering on a Dry water year (Table 1), the August 1 baseflow of 11 cfs (at the USGS Lompoc gage, USGS Water Supply Paper No. 361, pp. 108-109) lasted into September (measured on September 8, 1913 at 10 cfs). When the annual rainfall was no ‘better than average’, summer baseflows were 23 cfs on August 1, 1912 (P = 43.9%) and 20 cfs on August 1, 1910 (P = 33.4%) near Lompoc. By comparison, Contemporary water years with similar P values had substantially lower summer baseflows: WY2003 (P = 37.6%) was flowing at 0.29 cfs at the Narrows near Lompoc and 0 cfs at ‘H’ Street near Lompoc on August 1st (Figure 1).
Figure 5. ‘Historic’ annual hydrographs of the Santa Ynez River near Lompoc (USGS Gaging Station No. 11134000) from WY1908 to WY1918. 12 Figure 6. ‘Contemporary’ annual hydrographs of the Santa Ynez River near Lompoc (USGS Gaging Station No. 11134000) from WY1990 to WY2012. 13 14
Both spaghetti plots exhibited highly variable daily average streamflows (Figure 5 and Figure 6).
An analysis focusing on daily average streamflows for a particular calendar day would find extreme variability and might conclude that daily average streamflows in the Santa Ynez River Basin were extremely unpredictable. For example, May 1st would exhibit a very wide range in daily average streamflow if tallied over decades of water years, ranked, and then analyzed as a flow duration curve. But the color-coding of water years (from P values in Table 1) revealed more order than chaos. The spaghetti plots showed that the magnitude, duration, frequency, and timing of streamflows were predictable if the water year type was known. The spaghetti plots also showed that water year classification was not the perfect solution accounting for interannual (between years) or intra-annual (within year) streamflow variability. One Dry WY among the Contemporary annual hydrographs had spring recession streamflows extending well past those of wetter years. But its hydrograph had an unseasonal (for Dry water years) and sizeable mid-April rainfall/runoff event that extended its spring recession streamflows into early-June (Figure 6).
Other general observations of spaghetti graphs by time of year included: (1) Beginning earlyMarch, Historic annual hydrographs for wetter water years gradually receded to approximately 20 cfs by mid-July for Above Normal WYs and into late-August for Wet and Extremely-Wet WYs (Figure 5). The one drier water year (WY1913), a borderline Below Normal – Dry WY (P = 67.8%, Table 1), receded by early-June. In contrast, Contemporary annual hydrographs are receding considerably earlier. Extremely Wet WYs can still recede into mid-August. But Above Normal WYs now recede no later than early-May (Figure 6). In drier water years, differences between Historic and Contemporary annual hydrographs are even more pronounced, (2) During winter, Historic storm events retained larger magnitude streamflows with broader storm recession limbs than in Contemporary annual hydrographs, and (3) Beginning late-January, Historic wetter water years maintained higher baseflows (approximately 150 cfs to 100 cfs) than maintained in Contemporary wetter water years (less than 50 cfs).
Each observed difference between the Historic and Contemporary spaghetti plots was considered potentially important to steelhead migration and warranted investigation. The two spaghetti plots emphasized that the only way to integrate inter-annual and intra-annual hydrologic variability 15 into our steelhead migration study was to keep each annual hydrograph intact throughout our analyses (i.e., not to destroy ecologically valuable information that would be lost if using flow direction curves).
2.3 Santa Cruz Creek: A Hydrologic Baseline Waiting to Happen An effective analytical strategy was comparing Contemporary streamflows of individual water years with what they would have been if unimpaired (i.e., without dams and diversions). If WY2003 had 30 days of daily average streamflows encouraging rapid adult steelhead migration near Lompoc, how many days would have occurred in WY2003 without dams and diversions? With an estimated unimpaired WY2003 annual hydrograph, this total number of days could be determined. If the annual total was 60 days, we could claim with some quantitative clarity that diversions and dams caused a 50% decline. Many such comparisons may not be that straightforward. But unimpaired annual hydrographs can provide powerful baselines from which to understand complex biological processes, such as steelhead migration, and for constructing quantitative management goals.
Attempts to correlate unimpaired SYR streamflows with streamflows from unregulated gaging stations (with long histories of gaging) outside the Santa Ynez River Basin (e.g., Sespe Creek) were unsuccessful. Instead, we re-focused ouroptions for estimating unimpaired streamflows by keeping within the SYR Basin. Prior to WY1920, SYR mainstem gaging was dedicated to reservoir planning and estimating potential water resources for the City of Santa Barbara. Stream gaging centered on the Gibraltar Dam Site (including Mono Creek upstream) (RM 73.5, DA = 219 mi2
) and close to Robinson Bridge just upstream of Lompoc (RM 14.6, DA = 790 mi2). A central mainstem location between these two gaging locations was San Lucas Bridge (DA = 430 mi2
). It was a gateway bridging the mountainous headwaters of the upper Santa Ynez River and the floodplains of the Lower Santa Ynez River (LSYR). Most steelhead would have had to pass under San Lucas Bridge at least three times during their lifetimes: as an egg transported by their mothers upstream, swimming downstream as a smolt seeking the Pacific Ocean or as a juvenile seeking better downstream habitat, and last as an adult heading back upstream to spawn. In our analyses, we needed tools for estimating mostly unimpaired streamflows passing under San Lucas Bridge before the dams (Pre-Gibraltar Dam Period), but also needed to know how much 16 the dams and groundwater pumping had changed unimpaired streamflows during the Gibraltar Dam and Cachuma/Bradbury Dam regulatory periods.
Daily average streamflows (Q) at San Lucas Bridge were estimated for WYs before WY1920 (when Gibraltar Dam began regulating river flows) by computing unit runoff at the Gibraltar Dam Site upstream (with a drainage area (DA) of 219 mi2 ). Unit runoff is streamflow (cfs)
divided by drainage area (mi2) at the point of streamflow measurement, giving a unit runoff in cfs/mi2. This unit runoff was then multiplied by the drainage area at San Lucas Bridge (430 mi2) to estimate Q at San Lucas Bridge. Even after Gibraltar Dam operations began, unimpaired streamflows for restricted portions of the annual hydrograph could still be estimated at San Lucas Bridge, using the same unit runoff methodology, when the small capacity of Gibraltar Reservoir quickly filled (often within one storm) and then spilled.
In WY1942, the USGS began continuously gaging Santa Cruz Creek, a large unimpaired tributary entering the mainstem between Gibraltar Dam and San Lucas Bridge (and that now flows directly into Cachuma Reservoir) (Figure 1). Its drainage area (76 mi2 ) comprised a
substantial share (36%) of the total drainage area between Gibraltar Dam and San Lucas Bridge (i.e., 430 mi2 – 219 mi2 = 211 mi2). After just a few trials, we successfully applied the unit runoff from USGS Gaging Station No. 11124500 Santa Cruz Creek nr Santa Ynez to estimate unimpaired streamflow at Gibraltar Dam and San Lucas Bridge. This became a practical tool for estimating unimpaired streamflow downstream as well. Our ‘discovery’ of this tool had already been recognized. As noted in USGS Water Supply Paper No. 1107 (p.88) published in 1951: “A short and fragmentary record for Santa Cruz Creek indicates that unit runoff from that relatively extensive area is about equal to that from the entire area above San Lucas Bridge.” If streamflows in the upper Santa Ynez River were already impaired before the Santa Cruz gaging station was established in WY1942, how could we know that its unit runoff was an accurate predictive tool? When Gibraltar Reservoir and Jameson Reservoir are both full and spilling, ‘unimpaired’ streamflows can be estimated. There were other ways as well. The mainstem Santa Ynez River USGS gaging station below Los Laureles Canyon (USGS Station No. 11123500), situated downstream of Gibraltar Dam and upstream of the Santa Cruz Creek confluence, has a drainage area of 277 mi2
. The drainage area at Los Laureles minus the drainage
17 area at Gibraltar Dam upstream (219 mi2
) provided an estimate of unimpaired unit winter runoff (after subtracting out the streamflow released from Gibraltar Dam from the Los Laureles streamflows) for comparison to the unit winter runoff computed the same day from Santa Cruz Creek.
Even though the USGS reports Santa Cruz Creek as not being gaged until WY1942, the agency had been taking numerous measurements at the mouth of Santa Cruz Creek and at San Lucas Bridge dating back to the early 1900’s. USGS Water Supply Paper No. 481 provides a short but complete set of miscellaneous streamflow measurements taken in WY1917 for evaluating the Creek unit runoff methodology. A particularly complete set of measurements was taken in WY1914 and WY1915, but not reported until WY1931 as ‘Miscellaneous’ measurements in the back of USGS Water Supply Paper No. 721. A few pertinent excerpts of these streamflow data were reproduced in Figure 7.
These early gaging data were used to test the Santa Cruz Creek unit runoff application for estimating unimpaired streamflows in the Santa Ynez River at San Lucas Bridge. Unit runoff from Santa Cruz Creek (DA = 74 mi2 at the gage) did not reliably predict daily average streamflows at peak runoff when applied to considerably larger drainage areas (e.g., DA at San Lucas Bridge is 430 mi2). Two explanatory factors were: (1) the inadequacy of having access to only fixed 24-hr averaged peak streamflows, and (2) routing of peak events downstream with the peak ‘wave’ of streamflow attenuating downstream. But accurate estimation of peak streamflows (with RCT depths considerably greater than 1.5 ft) was not critical to the fish passage analyses.
For non-peak winter streamflows during the adult steelhead migration season (December 15 through April 30 - based on the documented migration period from November to May by Fukushima and Lesh 1998), estimates of daily average unimpaired streamflows at Solvang and Lompoc were made by applying a 1.1 and 1.3 multiplier to estimated unimpaired streamflows at San Lucas Bridge, respectively. Both multipliers conservatively accounted for relatively minor winter groundwater contributions and occasionally considerable (usually during peak runoff) tributary accretion downstream of San Lucas Bridge. Neither multiplier was used to estimate unimpaired summer baseflows below San Lucas Bridge.
Figure 7. S
and WY19
elected photo
15 reported i
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18 1914
19 3 Adult Steelhead Passage Opportunity Days in the Lower Santa Ynez River
3.1 Introduction
A primary study goal was to measure and evaluate whether, and to what extent, the Gibraltar Dam Period and the Cachuma/Bradbury Dam Period affected annual adult steelhead spawning migration in the Lower Santa Ynez River (LSYR). A passage opportunity has been based on a minimal streamflow condition that “allows steelhead to move among habitats” (Cachuma Operation and Maintenance Board, 2008). An Adult Steelhead Passage Opportunity Day was our primary dependent variable. The NMFS BiOp (2000) relies on the SYRTAC (1999, p. 1-2) fish passage study recommendation for the Lower Santa Ynez River mainstem of Q = 25 cfs as the threshold (minimum) adult passage streamflow that “was required to allow adult steelhead to migrate upstream.” Every day within a water year’s adult steelhead migration season was considered a passage opportunity in the NMFS BiOp (2000) if the daily average streamflow equaled or exceeded 25 cfs.
Annual hydrographs could not be used to assess adult steelhead passage without a quantitative relationship developed between streamflow and riffle depth. Even then, adult steelhead behavior is likely as important as riffle depths (or even more important) in determining how annual hydrographs accommodate passage. But riffle depth offered the most tractable, quantitative analytical approach, at least initially, to this highly complex activity. By establishing separate threshold riffle depths that impede and promote adult migration, streamflows corresponding to these threshold riffle depths were assessed in each annual hydrograph. By assessing individual annual hydrographs, we had a scientifically defensible estimate for the total number, seasonal timing, and duration of days that mainstem riffles either impeded or promoted steelhead passage.
Multiple large-magnitude storms in wetter water years should generate more passage opportunities than generated in dry water years. Therefore, we expected decreasing total annual passage opportunities (i.e., fewer Adult Passage Opportunity Days) with increasing P-values (Total Annual Precipitation Exceedence in Table 1) independent of potential opportunity reductions attributable to flow regulation and diversion. The same total annual precipitation, and 20 therefore the same P-value, experienced by several water years can be distributed in widely different patterns (e.g., resulting in a water year with one big flood or a water year with several small floods). Therefore, we expected considerable variability in total annual Adult Passage Opportunity Days among water years with similar P-values. Both expectations were considered important for assessing potential effects of flow regulation and diversion on steelhead spawning migration.
Specific study objectives were to: (1) estimate adult passage streamflow thresholds independent of the SYRTC 1999 Study’s 25 cfs streamflow threshold for the Lower SYR, (2) incorporate inter-annual (among water years) and intra-annual (within water year) hydrograph variability into the passage opportunity analysis, and (3) offer context for assessing whether losses in annual passage opportunities during the Gibraltar Dam Period and Cachuma/Bradbury Dam Period, relative to passage during the Pre-Gibraltar Period, have been significant.
3.2 Minimum Adult Steelhead Passage Depth
Adult steelhead migration is a complex activity with no on/off switch. However, the starting point in most passage evaluations typically begins by adopting a minimum passage depth.
Including a freeboard depth of 0.1 ft, a total streamflow depth of 0.6 ft (7.2 inches) will keep an adult’s back inundated (but not its dorsal fin or caudal fin) (Figure 8). A 0.6 ft minimum depth often is used in quantifying the minimum passage streamflow, presuming that an adult’s proclivity for migration would be unchanged at greater depths. However, this minimum depth does not take into account swimming performance, where an adult’s caudal fin should be immersed for effective propulsion. Adding other physical uncertainties (e.g., the uniformity of the channelbed’s surface layer typography and particle size) as a margin of error in a real-world setting, 0.8 ft (9.6 inches) would be a minimum passage depth that might not physically impede how effortlessly an adult steelhead navigates upstream. An adult steelhead’s migration rate would likely still be largely affected at this minimum depth of 0.8 ft in the SYR mainstem, relative to a rate an adult might be capable under ideal conditions (especially those behavioral), but its physical stress and inefficient energy expenditure should be minimized. Below this minimum streamflow threshold, adult passage will become progressively more difficult with the migration rate also progressively declining. The scientific literature provides little guidance on a quantitat
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22 migration streamflows that indirectly include a passage corridor. In the early 1970s, Thompson was faced with the same dilemma still confronting fisheries biologists today: the available ‘science’ for recommending passage streamflows has not progressed much beyond noting how much water depth is required to inundate an adult steelhead’s back. He proposed a simple, fieldoriented approach (now called the Thompson Method (TPM)) that indirectly provides a migration corridor without explicitly measuring one.
Thompson imposed two channel-width criteria for establishing a continuous migration corridor through an entire riffle. CDFW’s Instream Flow Program recently issued its standard operating procedure for critical riffle analysis of salmon and trout passage (CDFG 2012) that required both Thompson width criteria for developing a minimum passage flow (with the one generating the greatest streamflow becoming the recommended minimum passage flow):
1. At least 10% of the entire length of the transect must be contiguous for the minimum depth established for the target fish; and
2. A total of at least 25% of the entire transect must be at least the minimum depth established for passage of the target fish.
The 10% contiguous corridor width requires minimum riffle depths at both ends (the ‘bookend’ minimum depths) (Figure 9). All depths bracketed by the bookends will be of equal depth or greater. If the riffle being assessed is uniform, then the 25% entire transect requirement also would be contiguous, with all depths equal to or greater than the selected minimum passage depth. SYRTAC (1999) assessed 0.6 ft and 0.5 ft as minimum passage depths.
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24 occupied by perennial terrestrial plants, but including gravel bars, and lying between the toe of each bank.
The Thompson Method requires cross sections strategically located where the channel would be most likely to interfere with upstream adult migration (labeled ‘critical riffles’). SYRTAC (1999) used the Thompson Method but argued for modifying the transect requirement: A modification of the upstream passage criteria for salmon and steelhead developed by Thompson (1972) was used to determine when conditions were appropriate for passage. In this modification, the 10 and 25 percent width suggested for passage are allied to the wetted width of the channel, rather than the length of the transect from headpin to headpin. These studies indicated that a minimum flow of 25 cfs was required to allow adult steelhead to migrate upstream.
The Thompson Method’s application of the minimum depth criteria established bookend minimum depths which guaranteed greater depths at the recommended minimum passage flow.
This provision also provided a sufficiently wide migration corridor if the entire transect was used, as intended, and not shortened to the wetted width (i.e., total transect width changing with streamflow). TPM’s (and now, CDFW’s) 25% cross-section requirement basically expands the 10% cross-section contiguous zone requirement into a 25% contiguous zone in uniform riffles (i.e., a classic shallow ‘v’ cross section) because the 25% greatest depths exceeding the selected minimum will bracket the thalweg (Figure 9). This provides a wider migration route through an alternating bar’s riffle/pool morphology with much of this 25% zone deeper than the minimum passage depth, with the greatest depth at the thalweg. Narrowing the transect width not only narrows the migration corridor but also decreases depths greater than the minimum depth within the migration corridor (the greatest depth being the thalweg).
These issues led us to re-examine the minimum adult passage streamflow of 25 cfs for the mainstem LSYR: (1) changed Thompson criteria, (2) in Appendix Table 1 of SYRTAC (1999), Transect ‘Lompoc 2’ met a 3 ft wide corridor requirement and a 0.5 ft minimum depth with only 5 cfs yet met the 25% width criterion using a 0.6 ft minimum depth also with 5 cfs. This cross section should not be considered a ‘critical’ location; other cross sections had similar issues, and (3) use of shallow minimum passage depths. The ‘H’ Street mainstem section of the Santa Ynez River past Lompoc (USGS Gaging Sta. No. 11134000) poses a challenge under impaired annual 25 hydrographs. The mainstem SYR channel is confined at flood flows with a channelbed composed of sand, coarse gravel, and a few restricted cobble bar features. These two features have resulted in a highly mobile bed with a frequently shifting thalweg highly affected by riparian vegetation. In December 2012, the channelbed was dry. However, after two days of tracing likely migration routes with a hand level, a surveyed depth of 0.8 ft at the poorlyexpressed riffle-crest thalweg depth could provide migrating adults minimum depths to negotiate the weakly-expressed thalweg dominated by a complex mosaic of woody-vegetation (generating localized scour pockets that could strand adults). The channel morphology also is interspersed with willow clumps associated with subtle bar features and scour pockets. As streamflows rise, the small scour pockets associated with the willow clumps and subtle bars eventually would connect to form a shallow, diffuse migration corridor within the active channel. Using many subtle riffle crests as benchmark elevations during the December 2012 fieldtrip, a minimum flow depth of 0.8 ft deep, preferably 1.0 ft and greater, would be needed to achieve this connection.
Neither a 5 cfs streamflow minimum passage streamflow (estimated at SYRTAC Transect No. 2) nor a 25 cfs streamflow can provide acceptable passage conditions in the Lompoc floodplain.
3.4 Riffle Crest Thalwegs (RCTs) in the Lower Santa Ynez River: Estimating Riffle Depth as a Function of Daily Average Streamflow (Q) Streamflow depths in the Santa Ynez River Basin have been monitored by the USGS and the City of Santa Barbara since the late-1800’s. USGS streamflow gaging requires a quantitative relationship (an equation) between water surface elevation, referenced as ‘stage height’ on gaging station gage plates (measured in units of 0.01 ft), and streamflow (measured in units of cubic feet per second (cfs)). Each water surface elevation is assigned a discrete streamflow derived from extensive field measurement. With this relationship established, USGS hydrographers monitor stage height continuously over 24 hours to estimate a mean daily average streamflow (Q). This empirically-derived equation for Stage–Q relationships, plotted, is called the Stage-Q rating curve. Typically, stage increments on the gage plate and stages reported in the rating curves are arbitrary (not referenced to true elevation).
Although there is this huge database of streamflows, water depths, and Stage-Q rating curves, USGS gaging has not been done in riffles. This ‘deficiency’ became a critical challenge to our passage a
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