Agenda packet — Arroyo Grande City Council, July 25, 2023 (part 3 of 8)

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Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Conflict with or obstruct implementation of the
applicable air quality plan?
b) Violate any air quality standard or contribute
substantially to an existing or projected air quality
violation?
c) Result in a cumulatively considerable net increase of any criteria pollutant for which the project region is in non-attainment under an applicable federal or state
ambient air quality standard (including releasing
emissions which exceed quantitative thresholds for
ozone precursors)?
d) Expose sensitive receptors to substantial pollutant
concentrations?
e) Create objectionable odors affecting a substantial
number of people?
Discussion
a: No impacts.
b-c: The San Luis Obispo County Air Pollution Control District (APCD) has developed the CEQA Air Quality Handbook to evaluate project specific impacts and determine if air quality mitigation measures are needed, or if potentially significant impacts could result. The City refers to this Handbook for all projects subject to CEQA. Although the construction phase of the project is below the thresholds for significance, some mitigation is recommended. Construction for this project includes grading to expand the wetland area and to create the sedimentation basin. The “operation” phase of this project would include periodic maintenance of the sedimentation basin and is considered insignificant. It is anticipated that sedimentation removal might occur every five (5) to ten (10) years, and would largely depend on the severity of storm conditions.

According to the general operational screening criteria in the APCD Handbook, the grading associated with the proposed project is not expected to generate potentially significant air quality impacts.

However, emissions associated with project construction could affect adjacent properties and would add to the cumulatively significant effect that results in basin-wide exceedance of air quality standards.

These temporary fugitive dust and combustion emissions can impact local air quality. Implementation of the following mitigation measures will reduce air quality impacts to a less than significant level:

MM 3.1: The following conditions shall be included on all project plans and adhered to for all grading-related permits:

Reduce the amount of disturbed area where possible.

Use water trucks or sprinkler systems in sufficient quantities to prevent airborne dust from leaving the site. Increase watering frequency when wind speeds exceed 15 MPH.

Reclaimed (non-potable) water shall be used whenever possible.

All dirt stockpile areas should be sprayed daily or as needed using reclaimed (nonpotable) water when feasible.

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Exposed ground areas that are planned to be reworked more than one (1) month after initial grading should be sown with a fast-germinating native grass seed and watered until vegetation is established.

All areas to be paved (i.e. access road to the sediment basin) should be completed as soon as possible.

All trucks hauling dirt, sand, soil or other loose materials are to be covered or shall maintain at least two (2) feet of freeboard (minimum vertical distance between top of load and top of trailer) in accordance with CVC Section 23114.

Streets shall be swept at the end of each day if visible soil material is carried onto adjacent paved roads. Water sweepers with reclaimed (non-potable) water should be used where feasible.

Diesel idling shall not be permitted.

Signs that specify the no idling requirement shall be posted and enforced at the construction site.

Use of alternative-fueled equipment is recommended whenever possible.

The contractor shall designate a person or persons to monitor and implement these measures as necessary to minimize dust complaints, reduce visible emissions below 20% opacity and to prevent the transport of dust off-site. The name and telephone number of such persons shall be provided to the Air Pollution Control District (APCD) prior to the start of any grading-related activities. (See MM 9.1 for erosion control measures).

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit and during construction MM 3.2: All portable equipment (50 horsepower or greater) used during grading operations must be issued a permit by either the California Air Resources Board (CARB) or the APCD. (Contact the APCD Engineering Division at (805) 781-5912 for specific information regarding permitting requirements prior to start of the project).

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit and during construction d-e: No impacts.

4. Biological Resources
Environmental Setting
The project area includes the confluence of Corbett Creek and Carpenter Canyon Creek as well as the confluence of Corbett Creek and Arroyo Grande Creek. Corbett Creek is a perennial creek that carries flow except in drought years. The property has a long history of livestock grazing, and there has been some modification of natural hydrology by re-alignment of the creeks and construction of a berm.

To determine the extent and quality of wetland habitat on the project site, and whether portions of the project area were eligible for wetland protection and restoration through the Wetland Reserve Program

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(WRP), a report was conducted by the Natural Resources Conservation Service (NRCS) in December 2006. According to the report, the Clark Property does not contain any land that would be eligible for the Wetland Reserve Program. The site contains small areas of natural wetlands in four (4) delineations and the remaining land subject to the conservation easement is considered non-wetland.

The project site contains a variety of non-native and native plant species, with willows being the dominant native tree species. The prevailing understory species present include German ivy, poison hemlock, California blackberry, hoary nettle, poison oak, and morning glories (Denise Duffy and Associates, 2003). According to the Tally Ho Creek Planning Project Technical Memo Appendices prepared by Waterways Consulting, Inc. (June 2010), there are several identified special status plant and wildlife species that are likely present, although were not observed during the site inventory. These include Hoover’s bent grass (Agrostis hooveri), black-flowered figwort (Scrophularia atrata), San Bernardino aster (Symphyotricham defoliatum), California red-legged frog (Rana aurora draytonii), Southwestern pond turtle (Actinemys marmorata pallid), and the Yellow Warbler (Dendroica petechia).

The U.S. Fish and Wildlife Service (USFWS) and California Department of Fish and Wildlife (CDFW) have regulatory responsibility for the protection of special status plant and wildlife species. “Special status” species are selected for protection because they are rare and/or subject to population and habitat declines. Special status is a general term for species that are afforded varying levels of regulatory protection.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Have a substantial adverse effect, either directly or through habitat modification, on any species identified as a sensitive, candidate, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Wildlife or the
U.S. Fish and Wildlife Service?
b) Have a substantial adverse effect on any riparian
habitat or other sensitive natural community identified in local or regional plans, policies, or regulations, or by the California Department of Fish and Wildlife or the
U.S. Fish and Wildlife Service?
c) Have a substantial adverse effect on federally
protected wetlands, as defined by §404 of the Clean
Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling,
hydrological interruption, or other means?
d) Interfere substantially with the movement of any
native resident or migratory fish or wildlife species or with established native resident or migratory wildlife
corridors, or impede the use of native wildlife nursery sites?
e) Conflict with any local policies or ordinances
protecting biological resources, such as a tree
preservation policy or ordinance?

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f) Conflict with the provisions of an adopted Habitat
Conservation Plan, Natural Community Conservation
Plan, or other approved local, regional, or state habitat conservation plan?
Discussion
a-d: With the mitigation measures identified below, it is not anticipated that the project will have a significant impact on biological resources due to the historic equestrian use of the site and the short duration of construction/grading activities. The site is dominated by non-native plants except for willows. The purpose of creating the sedimentation basin and enhancing the floodplain area is to first impede flooding downstream, and second to enhance the native habitat. It is expected that the long term benefits of restoring the floodplain and riparian habitat will outweigh short term impacts.

Although the project will incorporate requirements for any necessary permits from the California Department of Fish and Wildlife (CDFW) and United States Fish and Wildlife Service (USFWS), several mitigation measures are included to offset any potential short term impacts. The following measures are primarily designed to promote habitat avoidance.

MM 4.1: Construction/grading shall take place after the breeding season for the Yellow Warbler (April – July) to limit noise impacts. If construction/grading must start during this time period, surveys of nesting birds within the project vicinity shall be completed by a qualified wildlife biologist. If the surveys identify active nests of the Yellow Warbler within the project vicinity, all earthmoving activities shall cease until the chicks have fledged. The biologist shall provide the lead agency and responsible agencies with a written report of survey findings, and shall specify when the project work may safely commence.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager (in consultation with the U.S. Fish and Wildlife Service (USFWS) prior to proceeding with work) Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit
MM 4.2: A qualified wildlife biologist shall complete and submit to the lead agency and responsible agencies a pre-construction survey for California red-legged frogs and Southwestern pond turtles. The survey shall be conducted during the time period when these species are known to be active. If no individuals are found, construction may proceed. If individuals are found during the initial investigation, the biologist shall conduct clearance surveys for these species approximately one (1) week prior to construction. Individuals found within the construction area will either be relocated to similar, adjacent habitats at least fifty (50) yards outside of the project area, or held in captivity until construction is complete. The project area shall be monitored during construction and appropriate measures taken to ensure that the individuals of relocated species do not move into the construction area. The decision of whether to relocate the animals shall be made by the biologist, although all mitigation activities would have to occur within the framework of any permits issued by the USFWS and CDFG.

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Timing: Prior to issuance of grading permit and during construction MM 4.3: A qualified botanist shall conduct an initial site survey to map occurrence of Hoover’s bent grass, San Bernardino aster and black-flowered figwort. If sensitive plant species are found on site and determined to be potentially impacted, the botanist shall prepare procedures that ensure no net loss of plants. These include, but are not limited to, designating avoidance areas, transplanting the plant populations to an equivalent location on site, or replaced in-kind with new plants at a ratio of two (2) plants replaced for each one (1) lost or at a ratio acceptable to the botanist. The transplanted or replaced plants shall be monitored over a five (5) year period.

Any plants lost during this time period shall be replaced. The botanist shall prepare a planting, irrigation and maintenance plan that includes these provisions. If the botanist concludes that avoidance is a viable option, locations determined to be potentially impacted will be flagged against inadvertent or unintentional damage.

Timing: Prior to issuance of grading permit
MM 4.4: The applicant shall acquire appropriate resource agency permits and undertake protection measures as required by those agencies.

Level of Significance: Less than significant impact
Implementing Responsibility: Coastal San Luis Resource Conservation District Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit
e-f: No impacts.

5. Cultural Resources
Environmental Setting
Creeks are a focal area of concern for the purposes of cultural resource sensitivity due to the pre-history and historical activity that occurred along and extending from creeks. The Central Coastal Information Center under contract to the State Office of Historic Preservation (OHP) helps implement the California Historical Resources Information System (CHRIS). It integrates information on new resources and known resources into CHRIS, supplies information on resources and surveys to governments and supplies lists of consultants qualified to conduct historic preservation fieldwork within the area. The California Archaeological Site Inventory is the collection of Site Records, which has been acquired and managed by the Information Centers and the OHP since 1975. According to these records, no known cultural site is located in the immediate project vicinity. Of the nineteen (19) site investigations conducted within a half mile radius of the project site, four (4) of which were on adjoining properties, there was only one (1)

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site that revealed any positive results for archaeological resources, which was located about 0.4 mile south of the project site near Paulding Middle School.

By virtue of the project area including the confluence of two (2) creeks, there may be a likelihood of prehistoric or early historic occupation or use of the site even though there are no known sites in the vicinity. Additionally, the proposed project requires a limited amount of surface excavation for the purposes of collection of fine sediment and floodplain restoration.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Cause a substantial adverse change in the
significance of a historical resource, as defined in
§15064.5?
b) Cause a substantial adverse change in the
significance of an archaeological resource, pursuant to §15064.5?
c) Disturb any human remains, including those interred
outside of formal cemeteries?
Discussion
a-c: Although it is not anticipated that there are any impacts to archaeological/cultural resources, implementation of the mitigation measures below will ensure that no impacts will occur.

MM 5.1: In the event that prehistoric cultural materials or historic cultural materials are encountered, work in the immediate vicinity of the finds shall be suspended until reviewed by an archaeologist, and the City shall be notified immediately should such resources be discovered. The archaeologist shall work as quickly as possible to permit resumption of construction activities. It is preferred that location data of finds be recorded using a hand-held global positioning system (GPS) receiver.

If human remains are encountered and determined to be Native American in origin, the San Luis Obispo County coroner will notify the Native American Heritage Commission (NAHC) within 24 hours of the find. The NAHC shall identify the person or persons it believes to be the most likely descendent of the deceased Native American. The most likely descendent may make recommendations for means of treating or disposing of the human remains and any associated grave goods as provided in Public Resources Code Section 5097.98.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

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divert or temporarily halt ground disturbance operations in the area of discovery to allow evaluation of potentially significant cultural resources in consultation with Northern Chumash Tribal Council. For significant cultural resources, a Research Design and Data Recovery Program to mitigate impacts shall be prepared by the consulting archaeologist and approved by the City, then carried out using professional archaeological methods. If it can be demonstrated that a project will cause damage to a unique archaeological resource, the City may require reasonable efforts to be made to permit any or all of these resources to be preserved in place or left in an undisturbed state.” Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit

6. Geology and Soils
Environmental Setting
The site has varying topographical gradients but generally consist of a 2-5% northeasterly slope. The soils on the Corbett Creek watershed are derived from soft, highly erodible sandstones. High levels of sediment in the creek have come from several locations of erosion and flooding events. The highest profile erosion sources came from the clearing and grading of an upslope property on James Way for a housing development. In 2001, a combination of heavy rains and soils with a high to very high hazard rating for water erosion led to the sedimentation of the James Way stormwater ditch and Corbett Creek, in turn causing flooding to adjacent homes. Homes along Corbett Creek in some cases are as little as twenty feet (20’) from the creek and are not elevated. The sediment was deposited in Corbett Creek, raising the streambed. Sediment accumulation has created marsh-like wetland areas that alter the form and function of the creek, diminishing the in-stream habitat and the conveyance of water and sediment.

In addition to erosion, expansion of the urban fringe, road development and increases in impervious surfaces have resulted in changes in the timing and magnitude of peak flows in the creek. There are small berms in some localized areas along the north side of the active channel built by landowners.

Another factor affecting stream function is a four foot (4’) high head-cut in the creek (as of 2007). If the head-cut was to progress upstream 2,700 feet, approximately 7,000 cubic yards of sediment would mobilize (Swanson Hydrology & Geomorphology, 2008) and be transported downstream to Arroyo Grande Creek, impacting steelhead habitat and increasing flooding challenges in the Zone 1/1A flood control channel.

No active faulting is known to exist on or close to the subject property. The project is not within a known area containing serpentine or ultramafic rock or soils (i.e. low risk of naturally occurring asbestos).

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Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Expose people or structures to potential substantial adverse effects, including the risk of loss, injury, or death involving:
i) Rupture of a known earthquake fault, as
delineated on the most recent Alquist-Priolo
Earthquake Fault Zoning Map, issued by the State
Geologist for the area, or based on other
substantial evidence of a known fault? (Refer to
Division of Mines and Geology Special Publication

42.)
ii) Strong seismic ground shaking?
iii) Seismic-related ground failure, including
liquefaction?
iv) Landslides?
b) Result in substantial soil erosion or the loss of
topsoil?
c) Be located on a geologic unit or soil that is unstable, or that would become unstable, as a result of the
project and potentially result in on- or off-site
landslide, lateral spreading, subsidence, liquefaction, or collapse?
d) Be located on expansive soil, as defined in Table 18- 1-B of the Uniform Building Code (1994), creating
substantial risks to life or property?
e) Have soils incapable of adequately supporting the
use of septic tanks or alternative waste disposal
systems, where sewers are not available for the
disposal of waste water?
Discussion
a: No impacts.
b: The project is intended to alleviate risks from increasing head-cuts and deposition of sediment. The project does not alter geotechnical requirements or permit additional construction in geologically sensitive or hazardous areas. The project description integrates development and implementation of both short and long term Best Management Practices (BMPs) to address construction and long term maintenance of the sedimentation basins on the Clark Property, design of the head-cut remediation and BMPs for landowners on the project area.
c-e: No impacts.

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7. Greenhouse Gas (GHG) Emissions
Environmental Setting
The project area includes residential development adjacent to Corbett Creek except at the Village Core where there are four parcels zoned Village Core/Village Mixed Use. The Clark Property is mostly undeveloped and contains a barn, equestrian trails and corals. Project construction is limited to creation of a sedimentation basin and expansion of the floodplain within defined areas. Short term greenhouse gas (GHG) emissions would be generated from equipment used for grading operations and are considered less than significant. There is not an operational phase to this project except for periodic (every 5-10 years) maintenance of the sedimentation basin. Therefore, GHG emissions cease once the initial construction is complete.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Generate greenhouse gas emissions, either directly
or indirectly, that may have a significant effect on the environment?
b) Conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of
greenhouse gases?
Discussion
a: The amount of GHG emissions from construction activities do not exceed the cumulative impact thresholds established by the San Luis Obispo County Air Pollution Control District (APCD). It should be noted that Mitigation Measures 3.1 and 3.2 address equipment and idling requirements that have the dual benefit of reducing GHG emissions.
b: No impacts.

8. Hazards and Hazardous Materials
Environmental Setting
There are no known hazards or hazardous materials associated with the project site.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Create a significant hazard to the public or the
environment through the routine transport, use, or
disposal of hazardous materials?
b) Create a significant hazard to the public or the
environment through reasonably foreseeable upset
and/or accident conditions involving the release of
hazardous materials, substances, or waste into the
environment?

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c) Emit hazardous emissions or handle hazardous or
acutely hazardous materials, substances, or waste
within one-quarter mile of an existing or proposed
school?
d) Be located on a site which is included on a list of
hazardous materials sites, compiled pursuant to
Government Code §65962.5, and, as a result, create a
significant hazard to the public or environment?
e) Be located within an airport land use plan or, where such a plan has not been adopted, within two miles of
a public airport or public use airport? If so, would the project result in a safety hazard for people residing or working in the project area?
f) Be located in the vicinity of a private airstrip? If so, would the project result in a safety hazard for people
residing or working in the project area?
g) Impair implementation of or physically interfere
with an adopted emergency response plan or
emergency evacuation plan?
h) Expose people or structures to a significant risk of loss, injury, or death from wildland fires, including
areas where wildlands are adjacent to urbanized areas
or where residences are intermixed with wildlands?
Discussion
b: The project as proposed does not pose a significant hazard to the public or the environment.

However, in the unlikely event that there is an equipment malfunction producing an oil or gas spill, procedures shall be followed as outlined under MM 9.1 (preparation of a Storm Water Pollution Prevention Plan).
a, c- h: No impacts.

9. Hydrology and Water Quality
Environmental Setting
The project area includes the confluence of Corbett and Carpenter Canyon Creeks as well as the confluence of Corbett and Arroyo Grande Creeks. Except for drought years, Corbett Creek maintains perennial flow and meanders from the City limits near Highway 227 to Arroyo Grande Creek in the commercial core of the City’s Village area. It has an active low flow channel/bank full morphology that narrows to approximately two-four feet (2’-4’) wide near Arroyo Grande Creek. The creek travels through the backyards of residences on Tally Ho Road where there is persistent flooding. There is a four foot (4’) high head-cut in the creek that was initially observed by field crews in 2007. If the head-cut were to progress upstream 2,700 feet, approximately 7,000 cubic yards of sediment would mobilize (Swanson Hydrology & Geomorphology, 2008) and be transported downstream to Arroyo Grande Creek, impacting steelhead habitat and increasing flooding challenges in the Zone 1/1A flood control channel.

The project is intended to restore the riparian habitat and provide flood protection.

Construction/grading activities and exposed soil could cause temporary erosion; however, implementation of Best Management Practices (BMPs) that are integrated into the project description and the mitigation measures below will mitigate the impacts to less that significant.

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Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Violate any water quality standards or waste
discharge requirements?
b) Substantially deplete groundwater supplies or
interfere substantially with groundwater recharge,
such that there would be a net deficit in aquifer
volume or a lowering of the local groundwater table
level (e.g., the production rate of pre-existing nearby wells would drop to a level that would not support
existing land uses or planned uses for which permits
have been granted)?
c) Substantially alter the existing drainage pattern of the site or area, including through alteration of the
course of a stream or river, in a manner which would
result in substantial on- or off-site erosion or siltation? d) Substantially alter the existing drainage pattern of the site or area, including through alteration of the
course of a stream or river, or substantially increase
the rate or amount of surface runoff in a manner
which would result in on- or off-site flooding?
e) Create or contribute runoff water which would
exceed the capacity of existing or planned stormwater
drainage systems or provide substantial additional
sources of polluted runoff?
f) Substantially degrade water quality?
g) Place housing within a 100-year flood hazard area,
as mapped on a federal Flood Hazard Boundary or
Flood Insurance Rate Map, or other flood hazard
delineation map?
h) Place structures that would impede or redirect flood flows within a 100-year flood hazard area?
i) Expose people or structures to a significant risk of loss, injury, or death from flooding, including flooding resulting from the failure of a levee or dam?
j) Result in inundation by seiche, tsunami, or mudflow? Discussion
a, c-f, h-i: Potentially significant impacts from soil erosion and an increase in sediment and turbidity to Arroyo Grande Creek could result from project grading and construction. Potentially significant impacts on hydrology and water quality from construction related activities can be reduced to a less-thansignificant level with implementation of the mitigation measures listed below.

The project site is within a floodway where waters flood onto horse pastures and therefore water quality impacts from equestrian use and manure accumulation may also be a concern. The project may bring surface water more frequently in contact with pastures and manure. However, the project would

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not worsen the water quality situation since no more horses would be added to the site, and some of the area currently used for horse corrals and pasture would be allocated to floodwater detention and riparian habitat enhancement. It is unknown at this time what the water quality impacts from nitrogen or bacteria will be from the project. Water quality monitoring will be carried out as required by the Storm Water Pollution Prevention Plan. The property owner is interested in BMPs to manage manure through composting. These BMPs would reduce potential bacteria pollutant loading, and would be implemented separately from this project. The continued equestrian use is not considered a potentially significant impact.

There is a potential for berm failure that could impact downstream properties. This potential will be addressed through the design process, and applicable design standards will be used.

MM 9.1: The applicant shall prepare a Storm Water Pollution Prevention Plan (SWPPP) and Erosion Control Plan that specifies the implementation of Best Management Practices (BMPs) to avoid and minimize water quality impacts as required by the Regional Water Quality Control Board (RWQCB). At a minimum, the SWPPP and Erosion Control Plan shall include:

Designation of equipment and supply staging and storage areas at least 100 feet from the outside edge of the creek 25-foot setback area. All vehicle parking, routine equipment maintenance, fueling, minor repair, etc., and soil and material stockpile, shall be done only in the designated staging area.

Major vehicle/equipment maintenance, repair, and equipment washing shall be performed off site.

A wet and dry spill cleanup plan that specifies reporting requirements and immediate clean up to ensure no residual soil, surface water or groundwater contamination would remain after clean up.

Designating concrete mixer washout areas at least 100 feet from outside edge of the creek 25-foot setback with the use of appropriate containment or reuse practices.

A temporary and excess fill stockpile and disposal plan that ensures that no detrimental affects to receiving waters would result.

Required site preparation and erosion control BMPs for any work that may need to be completed after October 15.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit and during construction MM 9.2: To reduce erosion hazards due to construction activities, grading shall be minimized, and project contractors shall use runoff and sediment control structures, and/or establish a permanent plant cover on side slopes following construction.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

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Timing: Prior to issuance of grading permit and during construction MM 9.3: Erosion control and bank stabilization measures shall be implemented for any work that requires access to the creek, subject to CDFW approval through a Streambed Alteration Permit. These measures shall be clearly indicated on the grading plan.

Level of Significance: Less than significant impact
Implementing Responsibility: Coastal San Luis Resource Conservation District Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit and during construction MM 9.4: All temporary fill placed during project construction shall be removed at project completion and the area restored to approximate pre-project contours and topography.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to final inspection
MM 9.5: The project is located within a regulatory floodway. The applicant shall obtain all required permits from regulatory agencies (City of Arroyo Grande, Regional Water Quality Control Board, US Army Corps of Engineers, Ca. Dept. of Fish and Wildlife, etc.) and meet any relevant FEMA requirements associated with a regulatory floodway as necessary.

Level of Significance: Less than significant impact
Implementing Responsibility: Coastal San Luis Resource Conservation District Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit
b, g, j: No impacts.

10. Land Use and Planning
Environmental Setting
Surrounding uses are identified on Page 10 of the Initial Study. The proposed project was reviewed for consistency with policy and/or regulatory documents and appropriate land use (Land Use Element, Development Code, and Zoning Map). Outside the channel of Corbett Creek, the Clark Property is zoned for low density residential development at a density of 0.67 dwelling units/acre (a total of up to ten units). This project includes a conservation easement in perpetuity for 12.5 acres leaving a potential residential density of up to two (2) dwelling units. There are several antiquated lots in the project area that have been developed over time and the built density along Corbett Creek exceeds that of the low density residential designation. City policy C/OS 2 states that the City is to “safeguard important environmental and sensitive biological resources contribution to healthy, functioning ecosystems”.

Conserving land for the purposes of localized and downstream flood protection and habitat restoration is consistent with the City’s General Plan.

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Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Physically divide an established community?
b) Conflict with the applicable land use plan, policy, or regulation of any agency with jurisdiction over the
project (including, but not limited to, a general plan, specific plan, local coastal program, or zoning
ordinance) adopted for the purpose of avoiding or
mitigating an environmental effect?
c) Conflict with any applicable habitat conservation
plan or natural community conservation plan?
Discussion
a-c: No impacts.

11. Mineral Resources
Environmental Setting
The project site is not located within an area known to contain mineral resources. The site is not designated in the 2001 General Plan or identified in the Integrated Program EIR prepared for the General Plan as having locally-important mineral resources. There are no permitted mining operations located within the City limits of Arroyo Grande.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Result in the loss of availability of a known mineral resource that is or would be of value to the region and the residents of the state?
b) Result in the loss of availability of a locally
important mineral resource recovery site delineated
on a local general plan, specific plan, or other land use plan?
Discussion
a-b: No impacts.

12. Noise
Environmental Setting
The project site is primarily located within a low to medium density residential area. Existing ambient noise in the vicinity of the project is primarily generated by vehicular traffic. The Noise Element of the 2001 General Plan includes goals and implementation measures designed to reduce noise impacts on new development, and the City’s Noise Ordinance is the primary implementing tool of the Noise Element through specific noise standards.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact

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a) Generate or expose people to noise levels in excess
of standards established in a local general plan or
noise ordinance, or in other applicable local, state, or federal standards?
b) Generate or expose people to excessive
groundborne vibrations or groundborne noise levels?
c) Create a substantial permanent increase in ambient
noise levels in the vicinity of the project (above levels without the project)?
d) Create a substantial temporary or periodic increase
in ambient noise levels in the vicinity of the project, in excess of noise levels existing without the project?
e) Be located within an airport land use plan or, where such a plan has not been adopted, within two miles of
a public airport or public use airport? If so, would the project expose people residing or working in the
project area to excessive noise levels?
f) Be in the vicinity of a private airstrip? If so, would the project expose people residing or working in the
project area to excessive noise levels?
Discussion
a, d: Noise impacts associated with short term construction are expected to be minimal due to the need for limited surface excavation. Existing ambient noise in the vicinity of the project site is generated by vehicular traffic on Highway 227. The average sound levels during construction could exceed the threshold criteria when equipment is operating. This is considered a potentially significant impact that can be mitigated to a less-than-significant level with implementation of the below mitigation measures. There are no longterm or operational increases to ambient noise levels.

MM 12.1: Construction activities shall be restricted to the hours of 8:00 AM to 5:00 PM Monday through Friday. On-site equipment maintenance and servicing shall be confined to the same hours.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: During construction
MM 12.2: All construction equipment utilizing internal combustion engines shall be required to have mufflers that are in good condition. Stationary noise sources shall utilize noise reducing engine housing enclosures or noise screens.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: During construction

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MM 12.3: A note shall be placed on the construction plans that no more than two (2) pieces of major earth moving equipment shall be allowed to operate simultaneously.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit and during construction MM 12.4: All residential units located within five hundred feet (500’) of the construction site shall be sent a notice regarding the construction schedule of the project. A clearly legible sign shall also be posted at the project site. All notices and the signs shall indicate the expected dates and duration of construction activities, as well as provide a telephone number that residents can call to resolve any concerns about construction noise.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit and during construction b-c, e-f: No impacts.

13. Population and Housing
Environmental Setting
The project site is located within an established low and medium density residential area. Placing 12.5 acres of the roughly 16-acre Clark Property into a conservation easement would appear to reduce the residential development potential. However, because the 12.5-acre property is located within a floodplain area, it is unlikely that housing opportunities are lost. With 3.5 acres remaining of the 16 acre site, two (2) homes could be constructed at a density of 0.67 dwelling units per acre under the Residential Hillside (RH) zoning district. Downstream along the Corbett Creel reach, the only properties with development potential (i.e. vacant) are zoned Village Mixed Use (VMU) and Village Core (VC).

These zoning designations allow commercial and residential development. The proposed project would not impede development of these properties.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Induce substantial population growth in an area,
either directly (for example, by proposing new homes
and businesses) or indirectly (for example, through
extension of roads or other infrastructure)?
b) Displace substantial numbers of existing housing,
necessitating the construction of replacement housing
elsewhere?
c) Displace substantial numbers of people,
necessitating the construction of replacement housing
elsewhere?

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Discussion
a-c: No impacts.

14. Public Services
Environmental Setting
Public services to the project site are readily provided by the City of Arroyo Grande.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Result in significant environmental impacts from
construction associated with the provision of new or
physically altered governmental facilities, or the need for new or physically altered governmental facilities, to maintain acceptable service ratios, response times, or
other performance objectives for any of the public
services:

Fire protection?
Police protection?
Schools?
Parks?
Other public facilities?
Discussion
a: No impacts.

15. Recreation
Environmental Setting
The project site is a private facility with recreational uses and is not a public facility. The property owner utilizes the site primarily for corralling and grazing horses, with most of the site left in vacant open space. The project will not affect any existing private or public parks within the area, either by creating more demand for parks or diminishing the use of parks.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Increase the use of existing neighborhood and
regional parks or other recreational facilities, such that substantial physical deterioration of the facility would occur or be accelerated?
b) Include recreational facilities or require the
construction or expansion of recreational facilities that might have an adverse physical effect on the
environment?

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Discussion
a: No impacts.
b: The site will continue to serve as an equestrian recreational use. The existing facilities will remain, with some reduction in corral and grazing areas (see Exhibit B above under Background and Need for Project).

16. Transportation/Traffic
Environmental Setting
The project site is located within an established low and medium density residential area with access from Highway 227/Carpenter Canyon Road, Corbett Canyon Road, and Tally Ho Road where street parking is available and level of service is acceptable (LOS C or better). The project does not generate any trips that would impact the surrounding street network LOS or the backbone circulation system of the City.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Cause a substantial increase in traffic, in relation to existing traffic and the capacity of the street system
(i.e., a substantial increase in either the number of
vehicle trips, the volume to capacity ratio on roads, or congestion at intersections)?
b) Exceed, individually or cumulatively, the level of
service standards established by the county congestion
management agency for designated roads or
highways?
c) Cause a change in air traffic patterns, including
either an increase in traffic levels or a change in
location, that results in substantial safety risks?
d) Contain a design feature (e.g., sharp curves or a
dangerous intersection) or incompatible uses (e.g.,
farm equipment) that would substantially increase
hazards?
e) Result in inadequate emergency access?
f) Result in inadequate parking capacity?
g) Conflict with adopted policies, plans, or programs
supporting alternative transportation (e.g., bus
turnouts, bicycle racks)?
Discussion
a-g: No impacts.

17. Utilities and Service Systems
Environmental Setting
The project site is located within the incorporated City Limits of Arroyo Grande. Utilities are available from both the City and other regional entities.

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Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Exceed wastewater treatment restrictions or
standards of the applicable Regional Water Quality
Control Board?
b) Require or result in the construction of new water
or wastewater treatment facilities or expansion of
existing facilities?
Would the construction of these facilities cause
significant environmental effects?
c) Require or result in the construction of new storm
water drainage facilities or expansion of existing
facilities?
d) Have sufficient water supplies available to serve the project from existing entitlements and resources or
are new or expanded entitlements needed?
e) Result in a determination, by the wastewater
treatment provider that serves or may serve the
project, that it has adequate capacity to service the
project’s anticipated demand, in addition to the
provider’s existing commitments?
f) Be served by a landfill with sufficient permitted
capacity to accommodate the project’s solid waste
disposal needs?
g) Comply with federal, state, and local statutes and
regulations as they relate to solid waste?
Discussion
a-g: No impacts.

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Mandatory Findings of Significance
Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Substantially degrade the quality of the
environment, substantially reduce the habitat of a fish or wildlife species; cause a fish or wildlife population to drop below self-sustaining levels; threaten to
eliminate a plant or animal community; substantially
reduce the number or restrict the range of an
endangered, rare or threatened species; or eliminate
examples of the major periods of California history or
prehistory?
b) Have the potential to achieve short-term
environmental goals to the disadvantage of long-term
environmental goals?
c) Have possible environmental effects that are
individually limited but cumulatively considerable?
“Cumulatively considerable” means that the
incremental effects of an individual project are
significant when viewed in connection with the effects
of past projects, the effects of other current projects, and the effects of possible future projects.
d) Cause substantial adverse effects on human beings,
either directly or indirectly?
Discussion
a, c-d: The project is located within an established low and medium density residential area. The purpose of the project is to reduce flooding downstream and will enhance a wetland habitat area.

Isolated prehistoric materials may be present on the project site; however, the site does not serve as an example of a major period of California history or prehistory. The project will not cumulatively increase traffic or the demand for public services and utilities. With implementation of the proposed mitigation measures, the project will not cause substantial adverse effects on human beings or special status plant or animal species, either directly or indirectly.
b: No impacts.

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Summary of Mitigation Measures
MM 3.1: The following conditions shall be included on all project plans and adhered to for all grading-related permits:

Reduce the amount of disturbed area where possible.

Use water trucks or sprinkler systems in sufficient quantities to prevent airborne dust from leaving the site. Increase watering frequency when wind speeds exceed 15 MPH.

Reclaimed (non-potable) water shall be used whenever possible.

All dirt stockpile areas should be sprayed daily or as needed using reclaimed (nonpotable) water when feasible.

All areas to be paved (i.e. access road to the sediment basin) should be completed as soon as possible.

Streets shall be swept at the end of each day if visible soil material is carried onto adjacent paved roads. Water sweepers with reclaimed (non-potable) water should be used where feasible.

Diesel idling shall not be permitted.

Signs that specify the no idling requirement shall be posted and enforced at the construction site.

Use of alternative-fueled equipment is recommended whenever possible.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: During construction
MM 3.2: All portable equipment (50 horsepower or greater) used during grading operations must be issued a permit by either the California Air Resources Board (CARB) or the APCD. (Contact the APCD Engineering Division at (805) 781-5912 for specific information regarding permitting requirements prior to start of the project).

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit and during construction

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Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit

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MM 4.4: The applicant shall acquire appropriate resource agency permits and undertake protection measures as required by those agencies.

Level of Significance: Less than significant impact
Implementing Responsibility: Coastal San Luis Resource Conservation District Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit
MM 5.1: In the event that prehistoric cultural materials or historic cultural materials are encountered, work in the immediate vicinity of the finds shall be suspended until reviewed by an archaeologist, and the City shall be notified immediately should such resources be discovered. The archaeologist shall work as quickly as possible to permit resumption of construction activities. It is preferred that location data of finds be recorded using a hand-held global positioning system (GPS) receiver.

Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: During construction
MM 5.2: The note below shall be placed on the grading and improvement plans for the project:
“If human remains (burials) are encountered, the County Coroner shall be contacted immediately (805-781-4513). In the event that previously unidentified potentially significant cultural resources are discovered, an archaeologist shall have the authority to divert or temporarily halt ground disturbance operations in the area of discovery to allow evaluation of potentially significant cultural resources in consultation with Northern Chumash Tribal Council. For significant cultural resources, a Research Design and Data Recovery Program to mitigate impacts shall be prepared by the consulting archaeologist and approved by the City, then carried out using professional archaeological methods. If it can be demonstrated that a project will cause damage to a unique archaeological resource, the City may require reasonable efforts to be made to permit any or all of these resources to be preserved in place or left in an undisturbed state.” Level of Significance: Less than significant impact
Implementing Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit

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