Corona City Council
June 3, 2026

Attachment B
SGMA Tools to address DAC, drinking water, and
environmental beneficial uses and users
Stakeholder Engagement and Outreach
Clean Water Action, Community Water Center and Union of Concerned Scientists developed a guidance document
called Collaborating for success: Stakeholder engagement for Sustainable Groundwater Management Act
Implementation. It provides details on how to conduct
targeted and broad outreach and engagement during
Groundwater Sustainability Plan (GSP) development and
implementation. Conducting a targeted outreach involves:
• Developing a robust Stakeholder Communication and Engagement plan that includes outreach at frequented locations (schools, farmers markets, religious settings, events) across the plan area to increase the involvement and participation of disadvantaged communities, drinking water users and the environmental stakeholders. • Providing translation services during meetings and technical assistance to enable easy participation for non-English speaking stakeholders.
• GSP should adequately describe the process for requesting input from beneficial users and provide details on how input is incorporated into the GSP.

The Human Right to Water
The Human Right to Water Scorecard was developed
by Community Water Center, Leadership Counsel for
Justice and Accountability and Self Help Enterprises to aid Groundwater Sustainability Agencies (GSAs) in
prioritizing drinking water needs in SGMA. The
scorecard identifies elements that must exist in GSPs
to adequately protect the Human Right to Drinking
water.

Drinking Water Well Impact Mitigation Framework
The Drinking Water Well Impact Mitigation
Framework was developed by Community Water
Center, Leadership Counsel for Justice and
Accountability and Self Help Enterprises to aid
GSAs in the development and implementation of
their GSPs. The framework provides a clear
roadmap for how a GSA can best structure its
data gathering, monitoring network and
management actions to proactively monitor and
protect drinking water wells and mitigate impacts
should they occur.

Groundwater Resource Hub
The Nature Conservancy has
developed a suite of tools based on
best available science to help GSAs,
consultants, and stakeholders
efficiently incorporate nature into
GSPs. These tools and resources are
available online at
GroundwaterResourceHub.org. The
Nature Conservancy’s tools and
resources are intended to reduce
costs, shorten timelines, and increase
benefits for both people and nature.

Rooting Depth Database
The Plant Rooting Depth Database provides information that can help assess whether groundwater-dependent vegetation are accessing groundwater. Actual rooting depths will depend on the plant species and site-specific conditions, such as soil type and

availability of other water sources. Site-specific knowledge of depth to groundwater combined with rooting depths will help provide an understanding of the potential groundwater levels are needed to sustain GDEs.

How to use the database
The maximum rooting depth information in the Plant Rooting Depth Database is useful when verifying whether vegetation in the Natural Communities Commonly Associated with Groundwater (NC Dataset) are connected to groundwater. A 30 ft depth-togroundwater threshold, which is based on averaged global rooting depth data for phreatophytes1, is relevant for most plants identified in the NC Dataset since most plants have a max rooting depth of less than 30 feet. However, it is important to note that deeper thresholds are necessary for other plants that have reported maximum root depths that exceed the averaged 30 feet threshold, such as valley oak (Quercus lobata), Euphrates poplar (Populus euphratica), salt cedar (Tamarix spp.), and shadescale (Atriplex confertifolia). The Nature Conservancy advises that the reported max rooting depth for these deeper-rooted plants be used. For example, a depth-to groundwater threshold of 80 feet should be used instead of the 30 ft threshold, when verifying whether valley oak polygons from the NC Dataset are connected to groundwater. It is important to re-emphasize that actual rooting depth data are limited and will depend on the plant species and site-specific conditions such as soil and aquifer types, and availability to other water sources.

The Plant Rooting Depth Database is an Excel workbook composed of four worksheets:

1. California phreatophyte rooting depth data (included in the NC Dataset)

2. Global phreatophyte rooting depth data

3. Metadata

4. References
How the database was compiled
The Plant Rooting Depth Database is a compilation of rooting depth information for the groundwater-dependent plant species identified in the NC Dataset. Rooting depth data were compiled from published scientific literature and expert opinion through a crowdsourcing campaign. As more information becomes available, the database of rooting depths will be updated. Please Contact Us if you have additional rooting depth data for California phreatophytes.
1 Canadell, J., Jackson, R.B., Ehleringer, J.B. et al. 1996. Maximum rooting depth of vegetation types at the global scale. Oecologia 108, 583–595. https://doi.org/10.1007/BF00329030

GDE Pulse
GDE Pulse is a free online tool that allows Groundwater Sustainability Agencies to assess changes in groundwater dependent ecosystem (GDE) health using satellite, rainfall, and groundwater data. Remote sensing data from satellites has been used to monitor the health of vegetation all over the planet. GDE pulse has compiled 35 years of satellite imagery from NASA’s Landsat mission for every polygon in the Natural Communities Commonly Associated with Groundwater Dataset. The following datasets are available for downloading:

Normalized Difference Vegetation Index (NDVI) is a satellite-derived index that represents the greenness of vegetation. Healthy green vegetation tends to have a higher NDVI, while dead leaves have a lower NDVI. We calculated the average NDVI during the driest part of the year (July - Sept) to estimate vegetation health when the plants are most likely dependent on groundwater.

Normalized Difference Moisture Index (NDMI) is a satellite-derived index that represents water content in vegetation. NDMI is derived from the Near-Infrared (NIR) and Short-Wave Infrared (SWIR) channels. Vegetation with adequate access to water tends to have higher NDMI, while vegetation that is water stressed tends to have lower NDMI. We calculated the average NDVI during the driest part of the year (July– September) to estimate vegetation health when the plants are most likely dependent on groundwater.

Annual Precipitation is the total precipitation for the water year (October 1st – September 30th) from the PRISM dataset. The amount of local precipitation can affect vegetation with more precipitation generally leading to higher NDVI and NDMI.

Depth to Groundwater measurements provide an indication of the groundwater levels and changes over time for the surrounding area. We used groundwater well measurements from nearby (<1km) wells to estimate the depth to groundwater below the GDE based on the average elevation of the GDE (using a digital elevation model) minus the measured groundwater surface elevation.

ICONOS Mapper
Interconnected Surface Water in the Central Valley
ICONS maps the likely presence of interconnected surface water (ISW) in the Central Valley using depth to groundwater data. Using data from 2011-2018, the ISW dataset represents the likely connection between surface water and groundwater for rivers and streams in California’s Central Valley. It includes information on the mean, maximum, and minimum depth to groundwater for each stream segment over the years with available data, as well as the likely presence of ISW based on the minimum depth to groundwater. The Nature Conservancy developed this database, with guidance and input from expert academics, consultants, and state agencies.

We developed this dataset using groundwater elevation data available online from the California Department of Water Resources (DWR). DWR only provides this data for the Central Valley. For GSAs outside of the valley, who have groundwater well measurements, we recommend following our methods to determine likely ISW in your region. The Nature Conservancy’s ISW dataset should be used as a first step in reviewing ISW and should be supplemented with local or more recent groundwater depth data.

Attachment C
Freshwater Species Located in the Bedford-Coldwater Subbasin To assist in identifying the beneficial users of surface water necessary to assess the undesirable result “depletion of interconnected surface waters”, Attachment C provides a list of freshwater species located in the Bedford-Coldwater Subbasin. To produce the freshwater species list, we used ArcGIS to select features within the California Freshwater Species Database version 2.0.9 within the basin boundary. This database contains information on ~4,000 vertebrates, macroinvertebrates and vascular plants that depend on fresh water for at least one stage of their life cycle. The methods used to compile the California Freshwater Species Database can be found in Howard et al. 20151. The spatial database contains locality observations and/or distribution information from ~400 data sources. The database is housed in the California Department of Fish and Wildlife’s BIOS2 as well as on The Nature Conservancy’s science website3.

Scientific Name Common Name Legal Protected Status
Federal State Other
BIRDS
Icteria virens Yellow-breasted Chat Special Concern BSSC - Third priority
Vireo bellii pusillus Least Bell's Vireo Endangered Endangered Anas platyrhynchos Mallard
Ardea alba Great Egret
Ardea herodias Great Blue Heron
Butorides virescens Green Heron
Egretta thula Snowy Egret
Himantopus
mexicanus Black-necked Stilt
Megaceryle alcyon Belted Kingfisher
Oxyura jamaicensis Ruddy Duck
Pelecanus
erythrorhynchos
American White
Pelican Special Concern BSSC - First priority
Phalacrocorax
auritus
Double-crested
Cormorant
Podilymbus podiceps Pied-billed Grebe
Setophaga petechia Yellow Warbler BSSC - Second
priority

CRUSTACEANS
Crangonyx spp. Crangonyx spp.

Hyalella spp. Hyalella spp.

HERPS
Actinemys
marmorata
marmorata
Western Pond Turtle Special Concern ARSSC
Anaxyrus boreas
boreas Boreal Toad
1 Howard, J.K. et al. 2015. Patterns of Freshwater Species Richness, Endemism, and Vulnerability in California.

PLoSONE, 11(7). Available at: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0130710 2 California Department of Fish and Wildlife BIOS: https://www.wildlife.ca.gov/data/BIOS 3 Science for Conservation: https://www.scienceforconservation.org/products/california-freshwater-speciesdatabase

Anaxyrus californicus Arroyo Toad Endangered Special Concern ARSSC Pseudacris
cadaverina California Treefrog ARSSC
Rana draytonii California Red-legged
Frog Threatened Special Concern ARSSC
Spea hammondii Western Spadefoot
Under
Review in
the
Candidate or
Petition
Process
Special Concern ARSSC
Taricha torosa Coast Range Newt Special Concern ARSSC
Thamnophis
hammondii
hammondii
Two-striped
Gartersnake Special Concern ARSSC
Thamnophis sirtalis
sirtalis Common Gartersnake

INSECTS & OTHER INVERTS
Alotanypus spp. Alotanypus spp.

Argia spp. Argia spp.

Baetis adonis A Mayfly
Baetis spp. Baetis spp.

Cheumatopsyche
spp. Cheumatopsyche spp.

Chironomidae fam. Chironomidae fam.

Coenagrionidae fam. Coenagrionidae fam.

Cricotopus bicinctus Not on any status
lists
Cricotopus trifascia Not on any status
lists
Dicrotendipes spp. Dicrotendipes spp.

Eukiefferiella spp. Eukiefferiella spp.

Hetaerina spp. Hetaerina spp.

Hydropsyche spp. Hydropsyche spp.

Hydroptila spp. Hydroptila spp.

Hydroptilidae fam. Hydroptilidae fam.

Labrundinia spp. Labrundinia spp.

Libellulidae fam. Libellulidae fam.

Limnophyes spp. Limnophyes spp.

Micrasema spp. Micrasema spp.

Microtendipes spp. Microtendipes spp.

Nectopsyche spp. Nectopsyche spp.

Ochrotrichia spp. Ochrotrichia spp.

Parametriocnemus
spp.

Parametriocnemus
spp.

Paraphaenocladius
spp.

Paraphaenocladius
spp.

Paratendipes spp. Paratendipes spp.

Pentaneura spp. Pentaneura spp.

Phaenopsectra spp. Phaenopsectra spp.

Polypedilum spp. Polypedilum spp.

Procladius spp. Procladius spp.

Pseudochironomus
spp.

Pseudochironomus
spp.

Rheotanytarsus spp. Rheotanytarsus spp.

Simulium spp. Simulium spp.

Sperchon spp. Sperchon spp.

Tanytarsus spp. Tanytarsus spp.

Thienemannimyia
spp. Thienemannimyia spp.

Tinodes spp. Tinodes spp.

Tipulidae fam. Tipulidae fam.

Tribelos spp. Tribelos spp.

Tricorythodes spp. Tricorythodes spp.

MOLLUSKS
Ferrissia spp. Ferrissia spp.

Lymnaea spp. Lymnaea spp.

Menetus opercularis Button Sprite CS
Physa spp. Physa spp.

Planorbidae fam. Planorbidae fam.

PLANTS
Baccharis salicina Not on any status
lists
Cyperus
erythrorhizos Red
-root Flatsedge
Mimulus guttatus Common Large
Monkeyflower
Mimulus pilosus Not on any status
lists
Phacelia distans NA
Plagiobothrys
acanthocarpus Adobe Popcorn
-flower
Platanus racemosa California Sycamore
Pluchea odorata
odorata Scented Conyza
Pluchea sericea Arrow-weed
Rorippa palustris
palustris Bog Yellowcress
Rumex salicifolius
salicifolius Willow Dock
Salix gooddingii Goodding's Willow
Salix laevigata Polished Willow
Salix lasiandra
lasiandra
Not on any status
lists
Veronica anagallis-
aquatica NA
1 July 2019
IDENTIFYING GDEs UNDER SGMA
Best Practices for using the NC Dataset
The Sustainable Groundwater Management Act (SGMA) requires that groundwater dependent ecosystems (GDEs) be identified in Groundwater Sustainability Plans (GSPs). As a starting point, the Department of Water Resources (DWR) is providing the Natural Communities Commonly Associated with Groundwater Dataset (NC Dataset) online1 to help Groundwater Sustainability Agencies (GSAs), consultants, and stakeholders identify GDEs within individual groundwater basins. To apply information from the NC Dataset to local areas, GSAs should combine it with the best available science on local hydrology, geology, and groundwater levels to verify whether polygons in the NC dataset are likely supported by groundwater in an aquifer (Figure 1)2. This document highlights six best practices for using local groundwater data to confirm whether mapped features in the NC dataset are supported by groundwater.
1 NC Dataset Online Viewer: https://gis.water.ca.gov/app/NCDatasetViewer/ 2 California Department of Water Resources (DWR). 2018. Summary of the “Natural Communities Commonly Associated with Groundwater” Dataset and Online Web Viewer. Available at: https://water.ca.gov/-/media/DWR-Website/WebPages/Programs/Groundwater-Management/Data-and-Tools/Files/Statewide-Reports/Natural-Communities-DatasetSummary-Document.pdf Figure 1. Considerations for GDE identification.

Source: DWR2
Attachment D
2 The NC Dataset identifies vegetation and wetland features that are good indicators of a GDE. The dataset is comprised of 48 publicly available state and federal datasets that map vegetation, wetlands, springs, and seeps commonly associated with groundwater in California3. It was developed through a collaboration between DWR, the Department of Fish and Wildlife, and The Nature Conservancy (TNC).

TNC has also provided detailed guidance on identifying GDEs from the NC dataset4 on the Groundwater Resource Hub5, a website dedicated to GDEs.

BEST PRACTICE #1. Establishing a Connection to Groundwater Groundwater basins can be comprised of one continuous aquifer (Figure 2a) or multiple aquifers stacked on top of each other (Figure 2b). In unconfined aquifers (Figure 2a), using the depth-to-groundwater and the rooting depth of the vegetation is a reasonable method to infer groundwater dependence for GDEs. If groundwater is well below the rooting (and capillary) zone of the plants and any wetland features, the ecosystem is considered disconnected and groundwater management is not likely to affect the ecosystem (Figure 2d). However, it is important to consider local conditions (e.g., soil type, groundwater flow gradients, and aquifer parameters) and to review groundwater depth data from multiple seasons and water year types (wet and dry) because intermittent periods of high groundwater levels can replenish perched clay lenses that serve as the water source for GDEs (Figure 2c). Maintaining these natural groundwater fluctuations are important to sustaining GDE health.

Basins with a stacked series of aquifers (Figure 2b) may have varying levels of pumping across aquifers in the basin, depending on the production capacity or water quality associated with each aquifer. If pumping is concentrated in deeper aquifers, SGMA still requires GSAs to sustainably manage groundwater resources in shallow aquifers, such as perched aquifers, that support springs, surface water, domestic wells, and GDEs (Figure 2). This is because vertical groundwater gradients across aquifers may result in pumping from deeper aquifers to cause adverse impacts onto beneficial users reliant on shallow aquifers or interconnected surface water. The goal of SGMA is to sustainably manage groundwater resources for current and future social, economic, and environmental benefits. While groundwater pumping may not be currently occurring in a shallower aquifer, use of this water may become more appealing and economically viable in future years as pumping restrictions are placed on the deeper production aquifers in the basin to meet the sustainable yield and criteria. Thus, identifying GDEs in the basin should done irrespective to the amount of current pumping occurring in a particular aquifer, so that future impacts on GDEs due to new production can be avoided. A good rule of thumb to follow is: if groundwater can be pumped from a well - it’s an aquifer.

3 For more details on the mapping methods, refer to: Klausmeyer, K., J. Howard, T. Keeler-Wolf, K. Davis-Fadtke, R. Hull, A. Lyons. 2018. Mapping Indicators of Groundwater Dependent Ecosystems in California: Methods Report. San Francisco, California. Available at: https://groundwaterresourcehub.org/public/uploads/pdfs/iGDE_data_paper_20180423.pdf 4 “Groundwater Dependent Ecosystems under the Sustainable Groundwater Management Act: Guidance for Preparing Groundwater Sustainability Plans” is available at: https://groundwaterresourcehub.org/gde-tools/gsp-guidance-document/ 5 The Groundwater Resource Hub: www.GroundwaterResourceHub.org 3 Figure 2. Confirming whether an ecosystem is connected to groundwater. Top: (a) Under the ecosystem is an unconfined aquifer with depth-to-groundwater fluctuating seasonally and interannually within 30 feet from land surface. (b) Depth-to-groundwater in the shallow aquifer is connected to overlying ecosystem. Pumping predominately occurs in the confined aquifer, but pumping is possible in the shallow aquifer. Bottom: (c) Depthto-groundwater fluctuations are seasonally and interannually large, however, clay layers in the near surface prolong the ecosystem’s connection to groundwater. (d) Groundwater is disconnected from surface water, and any water in the vadose (unsaturated) zone is due to direct recharge from precipitation and indirect recharge under the surface water feature. These areas are not connected to groundwater and typically support species that do not require access to groundwater to survive.
4 BEST PRACTICE #2. Characterize Seasonal and Interannual Groundwater Conditions SGMA requires GSAs to describe current and historical groundwater conditions when identifying GDEs [23 CCR §354.16(g)]. Relying solely on the SGMA benchmark date (January 1, 2015) or any other single point in time to characterize groundwater conditions (e.g., depth-to-groundwater) is inadequate because managing groundwater conditions with data from one time point fails to capture the seasonal and interannual variability typical of California’s climate. DWR’s Best Management Practices document on water budgets6 recommends using 10 years of water supply and water budget information to describe how historical conditions have impacted the operation of the basin within sustainable yield, implying that a baseline7 could be determined based on data between 2005 and 2015. Using this or a similar time period, depending on data availability, is recommended for determining the depth-to-groundwater.

GDEs depend on groundwater levels being close enough to the land surface to interconnect with surface water systems or plant rooting networks. The most practical approach8 for a GSA to assess whether polygons in the NC dataset are connected to groundwater is to rely on groundwater elevation data. As detailed in TNC’s GDE guidance document4, one of the key factors to consider when mapping GDEs is to contour depth-to-groundwater in the aquifer that is supporting the ecosystem (see Best Practice #5).

Groundwater levels fluctuate over time and space due to California’s Mediterranean climate (dry summers and wet winters), climate change (flood and drought years), and subsurface heterogeneity in the subsurface (Figure 3). Many of California’s GDEs have adapted to dealing with intermittent periods of water stress, however if these groundwater conditions are prolonged, adverse impacts to GDEs can result. While depth-to-groundwater levels within 30 feet4 of the land surface are generally accepted as being a proxy for confirming that polygons in the NC dataset are supported by groundwater, it is highly advised that fluctuations in the groundwater regime be characterized to understand the seasonal and interannual groundwater variability in GDEs. Utilizing groundwater data from one point in time can misrepresent groundwater levels required by GDEs, and inadvertently result in adverse impacts to the GDEs. Time series data on groundwater elevations and depths are available on the SGMA Data Viewer9.

However, if insufficient data are available to describe groundwater conditions within or near polygons from the NC dataset, include those polygons in the GSP until data gaps are reconciled in the monitoring network (see Best Practice #6).

Figure 3. Example seasonality
and interannual variability in
depth-to-groundwater over
time. Selecting one point in time,
such as Spring 2018, to
characterize groundwater
conditions in GDEs fails to capture
what groundwater conditions are
necessary to maintain the
ecosystem status into the future so
adverse impacts are avoided.

6 DWR. 2016. Water Budget Best Management Practice. Available at:
https://water.ca.gov/LegacyFiles/groundwater/sgm/pdfs/BMP_Water_Budget_Final_2016-12-23.pdf 7 Baseline is defined under the GSP regulations as “historic information used to project future conditions for hydrology, water demand, and availability of surface water and to evaluate potential sustainable management practices of a basin.” [23 CCR §351(e)] 8 Groundwater reliance can also be confirmed via stable isotope analysis and geophysical surveys. For more information see The GDE Assessment Toolbox (Appendix IV, GDE Guidance Document for GSPs4). 9 SGMA Data Viewer: https://sgma.water.ca.gov/webgis/?appid=SGMADataViewer 5 BEST PRACTICE #3. Ecosystems Often Rely on Both Groundwater and Surface Water GDEs are plants and animals that rely on groundwater for all or some of its water needs, and thus can be supported by multiple water sources. The presence of non-groundwater sources (e.g., surface water, soil moisture in the vadose zone, applied water, treated wastewater effluent, urban stormwater, irrigated return flow) within and around a GDE does not preclude the possibility that it is supported by groundwater, too. SGMA defines GDEs as "ecological communities and species that depend on groundwater emerging from aquifers or on groundwater occurring near the ground surface" [23 CCR §351(m)]. Hence, depth-to-groundwater data should be used to identify whether NC polygons are supported by groundwater and should be considered GDEs. In addition, SGMA requires that significant and undesirable adverse impacts to beneficial users of surface water be avoided. Beneficial users of surface water include environmental users such as plants or animals10, which therefore must be considered when developing minimum thresholds for depletions of interconnected surface water.

GSAs are only responsible for impacts to GDEs resulting from groundwater conditions in the basin, so if adverse impacts to GDEs result from the diversion of applied water, treated wastewater, or irrigation return flow away from the GDE, then those impacts will be evaluated by other permitting requirements (e.g., CEQA) and may not be the responsibility of the GSA. However, if adverse impacts occur to the GDE due to changing groundwater conditions resulting from pumping or groundwater management activities, then the GSA would be responsible (Figure 4).

Figure 4. Ecosystems often depend on multiple sources of water. Top: (Left) Surface water and groundwater are interconnected, meaning that the GDE is supported by both groundwater and surface water. (Right) Ecosystems that are only reliant on non-groundwater sources are not groundwater-dependent. Bottom: (Left) An ecosystem that was once dependent on an interconnected surface water, but loses access to groundwater solely due to surface water diversions may not be the GSA’s responsibility. (Right) Groundwater dependent ecosystems once dependent on an interconnected surface water system, but loses that access due to groundwater pumping is the GSA’s responsibility.

10 For a list of environmental beneficial users of surface water by basin, visit: https://groundwaterresourcehub.org/gdetools/environmental-surface-water-beneficiaries/ 6 BEST PRACTICE #4. Select Representative Groundwater Wells Identifying GDEs in a basin requires that groundwater conditions are characterized to confirm whether polygons in the NC dataset are supported by the underlying aquifer. To do this, proximate groundwater wells should be identified to characterize groundwater conditions (Figure 5). When selecting representative wells, it is particularly important to consider the subsurface heterogeneity around NC polygons, especially near surface water features where groundwater and surface water interactions occur around heterogeneous stratigraphic units or aquitards formed by fluvial deposits. The following selection criteria can help ensure groundwater levels are representative of conditions within the GDE area:
● Choose wells that are within 5 kilometers (3.1 miles) of each NC Dataset polygons because they are more likely to reflect the local conditions relevant to the ecosystem. If there are no wells within 5km of the center of a NC dataset polygon, then there is insufficient information to remove the polygon based on groundwater depth. Instead, it should be retained as a potential GDE until there are sufficient data to determine whether or not the NC Dataset polygon is supported by groundwater.
● Choose wells that are screened within the surficial unconfined aquifer and capable of measuring the true water table.
● Avoid relying on wells that have insufficient information on the screened well depth interval for excluding GDEs because they could be providing data on the wrong aquifer. This type of well data should not be used to remove any NC polygons.

Figure 5. Selecting representative wells to characterize groundwater conditions near GDEs. 7 BEST PRACTICE #5. Contouring Groundwater Elevations
The common practice to contour depth-to-groundwater over a large area by interpolating measurements at monitoring wells is unsuitable for assessing whether an ecosystem is supported by groundwater. This practice causes errors when the land surface contains features like stream and wetland depressions because it assumes the land surface is constant across the landscape and depth-to-groundwater is constant below these low-lying areas (Figure 6a). A more accurate approach is to interpolate groundwater elevations at monitoring wells to get groundwater elevation contours across the landscape. This layer can then be subtracted from land surface elevations from a Digital Elevation Model (DEM)11 to estimate depth-to-groundwater contours across the landscape (Figure b; Figure 7). This will provide a much more accurate contours of depth-to-groundwater along streams and other land surface depressions where GDEs are commonly found.

Figure 6. Contouring depth-to-groundwater around surface water features and GDEs. (a) Groundwater level interpolation using depth-to-groundwater data from monitoring wells. (b) Groundwater level interpolation using groundwater elevation data from monitoring wells and DEM data.

Figure 7. Depth-to-groundwater contours in Northern California. (Left) Contours were interpolated using depth-to-groundwater measurements determined at each well. (Right) Contours were determined by interpolating groundwater elevation measurements at each well and superimposing ground surface elevation from DEM spatial data to generate depth-to-groundwater contours. The image on the right shows a more accurate depth-togroundwater estimate because it takes the local topography and elevation changes into account.

11 USGS Digital Elevation Model data products are described at: https://www.usgs.gov/core-sciencesystems/ngp/3dep/about-3dep-products-services and can be downloaded at: https://iewer.nationalmap.gov/basic/ 8 BEST PRACTICE #6. Best Available Science
Adaptive management is embedded within SGMA and provides a process to work toward sustainability over time by beginning with the best available information to make initial decisions, monitoring the results of those decisions, and using the data collected through monitoring programs to revise decisions in the future. In many situations, the hydrologic connection of NC dataset polygons will not initially be clearly understood if site-specific groundwater monitoring data are not available. If sufficient data are not available in time for the 2020/2022 plan, The Nature Conservancy strongly advises that questionable polygons from the NC dataset be included in the GSP until data gaps are reconciled in the monitoring network. Erring on the side of caution will help minimize inadvertent impacts to GDEs as a result of groundwater use and management actions during SGMA implementation.

ABOUT US
The Nature Conservancy is a science-based nonprofit organization whose mission is to conserve the lands and waters on which all life depends. To support successful SGMA implementation that meets the future needs of people, the economy, and the environment, TNC has developed tools and resources (www.groundwaterresourcehub.org) intended to reduce costs, shorten timelines, and increase benefits for both people and nature.

KEY DEFINITIONS
Groundwater basin is an aquifer or stacked series of aquifers with reasonably welldefined boundaries in a lateral direction, based on features that significantly impede groundwater flow, and a definable bottom. 23 CCR §341(g)(1) Groundwater dependent ecosystem (GDE) are ecological communities or species that depend on groundwater emerging from aquifers or on groundwater occurring near the ground surface. 23 CCR §351(m)
Interconnected surface water (ISW) surface water that is hydraulically connected at any point by a continuous saturated zone to the underlying aquifer and the overlying surface water is not completely depleted. 23 CCR §351(o) Principal aquifers are aquifers or aquifer systems that store, transmit, and yield significant or economic quantities of groundwater to wells, springs, or surface water systems. 23 CCR §351(aa)
1 Board Members:

Paul Rodriguez, TVWD
Jacque Casillas, City of Corona
Phil Williams, EVMWD
November 1, 2021
To: Ngoro Atume – Clean Water Action/Clean Water Fund
Dr. J. Pablo Ortiz-Partida – Union of Concerned Scientists Samantha Arthur – Audubon California
Danielle V. Dolan – Local Government Commission
E.J. Remson – The Nature Conservancy (TNC)
Melissa M. Rohde – The Nature Conservancy
Via email
RE: Public Comment Letter for the Bedford-Coldwater Basin Draft GSP Dated September 6, 2021 The Bedford-Coldwater Groundwater Sustainability Agency (BCGSA) appreciates your thorough review of our Groundwater Sustainability Plan (GSP). Throughout the process, the BCGSA has encouraged and welcomed public input, including the comment letter you submitted September 6, 2021. We have reviewed your comments and are editing the Bedford-Coldwater GSP in response to them. In addition, detailed responses to your comments are provided below. Your September 6 comment letter is attached for reference.

1. Comment: “Beneficial uses and users are not sufficiently considered in GSP development” Beneficial uses and users have been considered throughout the GSP. We are adding text to Chapter 2 of the GSP to more completely document groundwater users in the Basin.

A. Comment: “Human Right to Water considerations are not sufficiently incorporated.” Disadvantaged Communities, Drinking Water Users, and Tribes There are no disadvantaged communities (DACS) or tribal lands in the Basin, and the BCGSA believes there are very few active private wells, none of which are used for potable water supply in the Basin. We have clarified and added text in the Executive Summary and Chapters 2, 5 and 6 in response to your comment.

DACs
No DACs or severely disadvantaged communities (SDACs) have been identified in the Basin.

Tribal Lands
The comment takes issue with the statement that there are no tribal lands in the Basin when tribal entities were included in the list of stakeholders. The list of interested parties was developed to encourage public participation from any and all local and regional agencies, entities, and individuals.

The list included tribes with land in the region even though they do not have land within the Basin.

The BCGSA agencies have a long history of coordination with the regional tribal entities, and they always inform these entities of upcoming planning and/or infrastructure projects. The regional tribal entities take an interest in planning and infrastructure projects within the Basin and surrounding areas because there are important cultural resource sites within these areas. The BCGSA agencies 2 Board Members:

Paul Rodriguez, TVWD
Jacque Casillas, City of Corona
Phil Williams, EVMWD
and regional tribal entities coordinate to assess infrastructure project sites prior to groundbreaking to identify and protect potential cultural resources.

Comment: “The identification of…drinking water users …is not sufficient” While the BCGSA is aware of a small number of private wells in the Basin, a systematic well inventory identifying all active private wells has not been completed to date. This has been identified as a data gap in the GSP, as described in Section 6.2.7.1. The GSP also includes a project to address this data gap with a survey and inventory of active private wells throughout the Basin (Project 2, Section 8.7). This project was designed to locate and characterize the construction and use of existing private wells so that they can be included in sustainable management of the Basin.

The BCGSA solicited information from private well owners during public meetings and through email and postal outreach but received little response.

Comment: “The identification of Interconnected Surface Water (ISW) is insufficient” The comment claims that brief periods of interconnection can be ecologically significant, and we have not proven that those do not occur.
• If connection is due to surface flow creating losing stream conditions, then the gaged inflows document when surface flow is available that might establish connection. However:
o Surface inflow from the Lee Lake Management Area in the Elsinore Subbasin is not affected by groundwater management in the Bedford-Coldwater Basin. o Any habitat value from those periods results from surface inflow, not groundwater discharge.
• Groundwater discharge is not flashy, the way stream flow is. Thus, although air photos represent only moments in time, they are more likely to detect groundwater discharge than surface flow events.
• Revisiting the Google Earth air photos including wet and dry seasons, we see groundwater emerging into a dry channel starting around the golf course in 2002 to 2004, 2012, and 2018. Throughflow (probably continuous from the Lee Lake Management Area in the Elsinore Subbasin) appeared to happen in 2005 to 2006, November 2009, and June 2012.

However:
o Perennial pools could easily be hidden from view by tree canopy. In the absence of perennial pools, the years with groundwater discharge-supported water in channel are probably too infrequent to support fish. Perennial pools can be important refugia for fish and other aquatic species. A channel survey for pools is needed. o The years with throughflow or groundwater discharge to a dry channel were years with significant wastewater discharges from Eastern Municipal Water District and/or Elsinore Valley Municipal Water District (verified by wastewater discharges before 2012 and gaged flow at Lee Lake after 2012). The possible open water in February 2018 upstream of Cajalco Road was the only event in a year without Lee Lake outflow.

The comment from the reviewers does not give examples of aquatic species and life history stages for which brief periods of groundwater-supported flow every few years are “essential”. 3 Board Members:

Paul Rodriguez, TVWD
Jacque Casillas, City of Corona
Phil Williams, EVMWD
We discussed the possible existence of aquatic species in the Bedford-Coldwater portion of the Temescal Wash with the Natural Resources Manager of the Riverside County Resource Conservation District and none were identified.

The conclusion “Therefore, potential ISWs are not being identified, described nor managed in the GSP” is an exaggeration. “Potential ISW” is a TNC term, not a Sustainable Groundwater Management Act (SGMA) term. There is extensive description and analysis of surface flow, riparian vegetation, and wetlands in the GSP. The GSP is managing groundwater dependent ecosystems (GDEs) by not allowing depth to water near Temescal Wash to drop more than 35 feet below the ground surface, which is much more restrictive than the water level minimum threshold.

The GSA recognizes that there is limited data on groundwater/surface water interaction and have identified this as a data gap. As noted in Section 8 of the GSP, a management action is described to monitor water levels in the vicinity of Temescal Wash, and a specific project is proposed to gather more information on potential groundwater/surface water interaction (including dedicated monitoring wells) along Temescal Wash.

Comment: “The identification of Groundwater Dependent Ecosystems is insufficient, due to a lack of comprehensive, systematic analysis of the basin’s GDWs.” • The comment incorrectly states that some GDEs were disregarded based on the proximity or presence of surface water. This is an incorrect representation of the GSP, which stated that at “wetland” polygons where depth to groundwater is clearly too large to have groundwater discharge, any “wetland” vegetation is likely seasonally supported by rainfall and local ponding of runoff.
• The comment states that the lack of correlation between groundwater levels and normalized difference vegetation index (NDVI) changes is not evidence that NDVI is unrelated to groundwater levels. This fails to explain how an uncorrelated variable can be a causal factor in NDVI.
• The last bullet of “Recommendations” requests a “complete inventory” of fauna and flora in the Basin. The GSP discusses thirteen animal species by name and the five most abundant woody riparian vegetation species by name. All of the species discussed in the MSHCP and USARHCP that historically or presently occur along Temescal Wash were reviewed for potential groundwater dependence. A longer list of species associated with riparian or wetland areas—particularly ones not a focus in the HCPs—would not change the analysis results.
• The last bullet of “Recommendations” incorrectly states that “The GSP mentions the Western Riverside County Multispecies Habitat Conservation Plan but provides few details.” In fact, Sections 4.9.4 and 4.9.4.1 each include a full paragraph describing the Multiple Species Habitat Conservation Plan (MSHCP) content that relates to Temescal Wash and the Basin. Also, Section 6.7.2.3 includes a full paragraph describing all species mentioned in the MSHCP whose habitat areas overlap the Basin. Furthermore, the comment neglected to note that the GSP also reviewed and discussed the Upper Santa Ana River Habitat 4 Board Members:

Paul Rodriguez, TVWD
Jacque Casillas, City of Corona
Phil Williams, EVMWD
Conservation Plan (HCP), the Temescal Creek Native Fish Restoration Project, interviews with Resource Conservation District (RCD) staff (two additional long paragraphs in (Section 6.7.2.3), and review of U.S. Fish and Wildlife Service (USFWS) critical habitat maps (Section 4.9.4.1). In summary, the comment grossly mischaracterizes the evaluation of plant and animal species as inadequate when in fact, the consideration of relevant species was ample and the analysis went far beyond simply listing species, which by itself is of little value.

B. Comment: “Public trust resources are not sufficiently considered.” The GSA encouraged stakeholder engagement throughout the GSP process. Outreach efforts included website updates, individual phone calls, email, and postal mail. Domestic well owners were invited to participate but none indicated concern about the development of the GSP. As noted above there are no tribes in the Basin, although tribes in the region were invited to public meetings and consulted for the monitoring well construction project. We are updating our outreach plan to include continuing engagement during GSP implementation.

C. Comment: “Impacts of Minimum Thresholds, Measurable Objectives and Undesirable Results on beneficial uses and users are not sufficiently analyzed.” DACs and drinking water users
Aside from the production wells of the BCGSA agencies, there is only one small community water system in the Basin, the Glen Ivy Hot Springs. The Glen Ivy well is regulated as a small community water system and is included in the sustainable management criteria. This well is also included as a monitoring well in the GSP and water levels and quality in the well will continue to be assessed as part of GSP implementation. As indicated in prior responses, there are no DACs or SDACs in the Basin and there are no known private domestic potable wells in the Basin. Project 2 (Section 8.7) will identify all active private wells in the Basin so that they can be included in sustainable management.

Distinct maps for perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and sulfate contamination are unavailable due to lack of available data and not required by SGMA.

Groundwater Dependent Ecosystems and Interconnected Surface Waters The comment letter characterizes the sustainable management criteria (SMC) for interconnected surface water as observed groundwater elevations from the 2014-2016 drought. This is incorrect.

The SMC is not defined in terms of historical groundwater elevations during 2014-2016. The minimum threshold (MT) for ISW is very clearly stated in Section 6.7.6:
“The Minimum Threshold for depletion of interconnected surface water is the amount of depletion that occurs when the depth to water in wells near areas supporting phreatophytic riparian trees is greater than 35 feet for a period exceeding one year.” It should be noted that this MT is much more restrictive than the MT for chronic declines in groundwater levels (see GSP Table 6.1).
5 Board Members:

Paul Rodriguez, TVWD
Jacque Casillas, City of Corona
Phil Williams, EVMWD

2. Comment: “Climate change is not sufficiently considered.” The comment states that “the GSP did not consider the 2070 extremely wet and extremely dry climate scenarios in the projected water budget.” The comment appears to be referring to two alternative sets of monthly climate multipliers provided in the files of climate change factors downloadable from the SGMA Data Portal. Those sets of factors are labeled Drier/Extreme-Warming (DEW) and Wetter/Moderate-Warming (WMW). There is no requirement to use anything but the expected factors.

In fact, the California Department of Water Resources (DWR) document “Guidance for Climate Change Data Use during Groundwater Sustainability Plan Development” does not even mention the alternative data sets. Rather, Section 4.5 of the guidance document states that uncertainty in climate change predictions is represented by inter-annual variability in the 50-year future simulations. It also states that the evaluation of sustainability will be based on the “central tendency” of the climate change factors, which is represented by the primary climate factor data set. The DEW and WMW data sets are for optional research purposes. Therefore, the climate change analysis in the GSP is adequate.

Our interpretation is that DWR is requesting two water budgets only (2030 and 2070) and that “uncertainty” is represented by the interannual variability represented by the 50 years of analysis. In other words, the climate change scenario is itself an expression of uncertainty relative to the future baseline scenario. Also, projects are evaluated on the “central tendency”, which is based on the expected climate change factors (the ones used in the GSP climate change analysis). There is no requirement for additional analysis of alternative climate change factor sets such as those identified in the comment.

3. Comment: “Data gaps are not sufficiently identified and the GSP does not have a plan to eliminate them.”
Data gaps in the monitoring network have been identified and projects and management actions to address those data gaps are included in the GSP. The existing Project 1 (Section 8.6) has been more clearly defined to include the siting and installation of shallow monitoring wells to eliminate the data gap for interconnected surface water, as described in response 4 below.

4. Comment: “Projects and Management Actions do not sufficiently consider potential impacts or benefits to beneficial uses and users.”
Please see previous responses regarding the identification of beneficial users and uses, including the project already in the GSP to locate all private (including domestic) wells (Project 2, Section 8.7).

Regarding interconnected surface water and GDEs, Project 1 (Section 8.6) was clarified and expanded to add more detail in a phased approach involving well siting and permitting review, followed by construction of shallow monitoring wells along Temescal Wash where possible. A survey for perennial pools along the entire length of Temescal Wash in the Basin will also be conducted. The new wells along Temescal Wash will greatly increase the knowledge of groundwater conditions near the wash, and appropriate reduction in pumping to protect GDEs, if required (Management Action 4). 6 Board Members:

Paul Rodriguez, TVWD
Jacque Casillas, City of Corona
Phil Williams, EVMWD
Once again, thank you for your detailed review of the Bedford-Coldwater GSP. We hope these responses to your comments are helpful.

Sincerely,
Victor Harris
BCGSA Administrator
Attachment: “Public Comment Letter for the Bedford-Coldwater Basin Draft GSP” dated September 6, 2021
Bedford-Coldwater GSP

TODD GROUNDWATER,
H&H Water Resources,
and Stantec

APPENDIX G
Bedford-Coldwater GSP Numerical
Groundwater Model Documentation Report

BEDFORD-COLDWATER
BASIN

GROUNDWATER

SUSTAINABILITY PLAN

GROUNDWATER MODEL

DOCUMENTATION REPORT
November 2021
2490 Mariner Square Loop, Suite 215
Alameda, CA 94501
510.747.6920
www.toddgroundwater.com

SIGNATURE PAGE
_____________________________
Katherine White, PE
Senior Hydrologist
Todd Groundwater, Alameda, CA
_____________________________
Michael P. Maley, PG, CHg, CEG, PE
Principal Hydrogeologist
Todd Groundwater, Alameda, CA
Bedford-Coldwater GSP
Groundwater Model Report i TODD GROUNDWATER
Table of Contents

1. Introduction............................................................................................................................. 1

1.1. Scope and Objective ........................................................................................................ 1

1.2. Summary of Previous Models.......................................................................................... 1

2. Basin Geology and Structure ................................................................................................... 2

2.1. Bedford Coldwater Basin ................................................................................................. 2

2.1.1. Physiography............................................................................................................ 2

2.1.2. Hydrology................................................................................................................. 2

2.1.3. Management Areas.................................................................................................. 2

2.2. Regional Geology ............................................................................................................. 3

2.2.1. Geologic Units.......................................................................................................... 3

2.2.2. Faults........................................................................................................................ 4

2.2.3. Pull-Apart Basin........................................................................................................ 4

2.2.4. Definable Basin Bottom ........................................................................................... 5

2.3. Groundwater conditions.................................................................................................. 5

2.3.1. Aquifer...................................................................................................................... 5

2.3.2. Recharge and Discharge Areas................................................................................. 5

2.3.3. Primary Groundwater Uses...................................................................................... 6

3. Rainfall-Runoff-Recharge Model ............................................................................................. 7

3.1. Approach.......................................................................................................................... 7

3.2. Land Use and Recharge Zones......................................................................................... 8

3.3. Rainfall ............................................................................................................................. 9

3.4. Interception ..................................................................................................................... 9

3.5. Runoff and Infiltration ..................................................................................................... 9

3.6. Root Zone Depth and Moisture Content ....................................................................... 10

3.7. Evapotranspiration......................................................................................................... 11

3.8. Irrigation......................................................................................................................... 11

3.9. Deep Percolation from Root Zone to Shallow Groundwater......................................... 12

3.10. Movement of Shallow Groundwater to Deep Recharge and Stream Base Flow........... 12

3.11. Evapotranspiration by Riparian Vegetation................................................................... 13

3.12. Groundwater Inflow....................................................................................................... 13

3.13. Calibration of Rainfall-Runoff-Recharge Model............................................................. 14

4. Numerical Groundwater Model Development...................................................................... 15

4.1. General Approach .......................................................................................................... 15

4.2. Model Setup................................................................................................................... 15

4.2.1. Model Code Selection............................................................................................ 15

4.2.2. Base Period ............................................................................................................ 16

4.2.3. Model Domain and Grid......................................................................................... 16

4.2.4. Model Layers.......................................................................................................... 17

4.2.5. Faults...................................................................................................................... 18

4.2.6. Aquifer Conditions................................................................................................. 18

4.3. Boundary Conditions...................................................................................................... 19

4.3.1. Surface Recharge ................................................................................................... 19

4.3.2. Streams .................................................................................................................. 19

4.3.3. Mountain Front Recharge...................................................................................... 20

4.3.4. Evapotranspiration................................................................................................. 21

4.3.5. Groundwater Pumping........................................................................................... 22 Bedford-Coldwater GSP
Groundwater Model Report ii TODD GROUNDWATER

4.3.6. Recycled Water Recharge Ponds ........................................................................... 22

4.3.7. Quarries.................................................................................................................. 22

4.3.8. Subsurface Flow with Adjacent Groundwater Basins............................................ 23

4.4. Aquifer Properties.......................................................................................................... 24

4.4.1. Aquifer Characteristics........................................................................................... 24

4.4.2. Zone Approach....................................................................................................... 25

4.4.3. Hydraulic Conductivity ........................................................................................... 25

4.4.4. Vertical Conductance............................................................................................. 25

4.4.5. Specific Yield and Specific Storage......................................................................... 26

4.5. Initial Condition.............................................................................................................. 26

5. Historical Model Results........................................................................................................ 27

5.1. Calibration Methodology ............................................................................................... 27

5.1.1. Approach................................................................................................................ 27

5.1.2. Calibration Methodology ....................................................................................... 27

5.1.3. Primary and Alternative Calibration ...................................................................... 28

5.2. Statistical Calibration ..................................................................................................... 29

5.2.1. Primary Calibration Results.................................................................................... 29

5.2.2. Alternative Calibration Results .............................................................................. 30

5.2.3. Comparison to Previous Model Calibration for Coldwater MA............................. 31

5.3. Groundwater Level Trends............................................................................................. 32

5.3.1. Bedford MA Hydrographs...................................................................................... 32

5.3.2. Coldwater MA Hydrographs................................................................................... 32

5.4. Evaluation Of Groundwater Flow .................................................................................. 34

5.5. Model-Based Hydrologic Budget ................................................................................... 35

6. Simulation of Future Conditions............................................................................................ 37

6.1. Baseline Scenario ........................................................................................................... 37

6.1.1. Baseline Assumptions............................................................................................ 37

6.1.2. Baseline Water Budget Results.............................................................................. 38

6.1.3. Baseline Groundwater Flow Evaluation................................................................. 39

6.2. Growth and Climate Change Scenario ........................................................................... 39

6.2.1. Growth and Climate Change Assumptions............................................................ 39

6.2.2. Growth and Climate Change Scenario Water Budget Results............................... 40

6.2.3. Future Growth and Climate Change Groundwater Map ....................................... 41

7. SGMA Requirements.............................................................................................................. 43

7.1. Model Data Gaps ........................................................................................................... 43

7.2. Model Accuracy.............................................................................................................. 44

7.3. Limitations to Calibration............................................................................................... 44

8. References Cited.................................................................................................................... 46 List of Tables (all tables follow text except where noted) Table 1 Bedford-Coldwater Basin Land Use (acres) (in Text) Table 2 Average Annual Groundwater Pumping
Table 3 Aquifer Properties
Table 4 Summary of Primary Calibration for The Bedford-Coldwater Model (in Text) Table 5 Statistical Calibration by Well
Bedford-Coldwater GSP
Groundwater Model Report iii TODD GROUNDWATER
Table 6 Summary of Alternative Calibration for The Bedford-Coldwater Model (in Text) Table 7 Bedford-Coldwater GW Basin Water Balance (in acre-feet per year) - Historical Table 8 Bedford MA Water Balance (in acre-feet per year) - Historical Table 9 Coldwater MA Water Balance (in acre-feet per year) - Historical Table 10 Change in Groundwater in Storage (in acre-feet per year) - Historical Table 11 Bedford-Coldwater GW Basin Balance (in acre-feet per year) - Projected Future Baseline Table 12 Bedford MA Water Balance (in acre-feet per year) - Projected Future Baseline Table 13 Coldwater MA Water Balance (in acre-feet per year) - Projected Future Baseline Table 14 Change in Groundwater in Storage (in acre-feet per year) - Projected Future Baseline Table 15 Bedford-Coldwater GW Basin Water Balance (in acre-feet per year) - Projected Future Growth with Climate
Table 16 Bedford MA Water Balance (in acre-feet per year) - Projected Future Growth with Climate Change
Table 17 Coldwater MA Water Balance (in acre-feet per year) - Projected Future Growth with Climate Change
Table 18 Change in Groundwater in Storage (in acre-feet per year) - Projected Future Growth with Climate Change
List of Figures (all figures follow text)
Figure 1. Location and Topography of Bedford-Coldwater Basin Figure 2 Local Watersheds that Drain into the Bedford-Coldwater Basin Figure 3 Schematic Plan View Showing Faulting Associated with Pull-Apart Basins Figure 4 1990 and 2018 Land Use for Recharge Polygons
Figure 5 Average Annual Rainfall
Figure 6 Relationship of Rainfall to Infiltration
Figure 7 Rainfall to Runoff Calibration
Figure 8 Location of MODFLOW Model Domain
Figure 9 Location of Management Areas
Figure 10 Topographic Elevation of the Top of Model Layer 1 Figure 11 Bottom Elevation Distribution for Model Layer 1 Figure 12 Bottom Elevation Distribution for Model Layer 2 Figure 13 Bottom Elevation Distribution for Model Layer 3 Figure 14 Schematic NW-SE Cross Section to Illustrate Relative Model Layer Thicknesses Figure 15 Schematic NE-SW Cross Section to Illustrate Relative Model Layer Thicknesses Figure 16 Location of Faults Included in MODFLOW model
Figure 17 Location of Streams
Figure 18 Distribution of General Head Boundary Used for Mountain Front Recharge Figure 19 Distribution of Evapotranspiration (ET) Zones Figure 20 Location of Pumping Wells with Measured Pumping Rates Figure 21 Locations of Estimated Pumping for Historical Agriculture Figure 22 Annual Groundwater Pumping Volumes in Basin
Bedford-Coldwater GSP
Groundwater Model Report iv TODD GROUNDWATER
Figure 23 Location of Primary Quarry Areas and Wastewater Facilities Figure 24 Boundary Conditions Applied for Recharge Ponds, Quarries and Subsurface Flow Figure 25 Distribution of Aquifer Property Zones for Layers 1, 2 and 3 Figure 26 Initial Groundwater Conditions for Layer 2
Figure 27 Location of Monitoring Wells in MODFLOW Model in Bedford MA Figure 28 Location of Monitoring Wells in MODFLOW Model in Coldwater MA Figure 29 Scatter Plot Comparing Simulated to Measured Groundwater Levels Figure 30 Calibration Hydrographs Bedford MA North Temescal Wash Area Figure 31 Calibration Hydrographs Bedford MA North Temescal Wash Area Figure 32 Calibration Hydrographs Bedford MA Mid Temescal Wash Area Figure 33 Calibration Hydrographs Coldwater MA Coldwater Quarry Area Figure 34 Calibration Hydrographs Coldwater MA Mayhew Quarry Area Figure 35 Calibration Hydrographs Coldwater MA Other Quarry Area Figure 36 Calibration Hydrographs Coldwater MA North of Quarry Area Figure 37 Layer 1 Groundwater Elevations End of Simulation September 2018 Figure 38 Layer 1 Groundwater Elevations Near Highest Levels March 1995 Figure 39 Layer 1 Groundwater Elevations Near Lowest Levels October 2010 Figure 40 Simulated Change in Groundwater in Storage for Historical Simulation Figure 41 Simulated Groundwater Storage Change for Future Baseline Scenario Figure 42 Layer 1 Groundwater Elevations Future Baseline Scenario September 2068 Figure 43 2068 Land Use for Recharge Polygons for Future Growth Scenario Figure 44 Simulated Groundwater Storage Change for Growth-Climate Change Scenario Figure 45 Layer 1 Groundwater Elevations Future Growth Scenario September 2068 Bedford-Coldwater GSP
Groundwater Model Report 1 TODD GROUNDWATER

1. INTRODUCTION
The groundwater model was developed to support the Groundwater Sustainability Plan (GSP) for the Bedford-Coldwater Subbasin of the Elsinore Groundwater Basin (DWR Groundwater Basin 8-004.02) and is prepared in accordance with Sustainable Groundwater Management Act (SGMA). For convenience, DWR Basin 8-004.02 will be referred to as the Bedford-Coldwater Subbasin (Basin) in this memo.

1.1. SCOPE AND OBJECTIVE
SGMA effectively requires that groundwater modeling be used to demonstrate that a GSP will achieve sustainable basin operation. Various numerical model that has been developed, periodically updated, and used for various scenarios since the 1990s. The objective of this model was to simulate the surface water and groundwater model for the entire Basin that updates key parameters the Basin boundary, discretization, geologic layering, aquifer parameter distribution. The assessment and final model focuses on applicability to SGMA GSP regulations including consistency with DWR Best Management Practices for surface water and groundwater modeling (DWR, 2016). This comprehensive groundwater model serves as a quantitative tool for computing Basin-wide and management area specific water budgets as required by the SGMA GSP regulations.

1.2. SUMMARY OF PREVIOUS MODELS
The Basin Model (Bedford-Coldwater Model) incorporates the hydrologic, geologic and groundwater data to develop a numerical groundwater model to evaluate local water budgets and assess sustainability criteria. An earlier groundwater model was developed for use on the Coldwater Basin Recharge Feasibility Study (MWH, 2004). The Bedford-Coldwater Model builds on earlier data from the 2004 MWH model, and expands the previous model in order to cover the rest of the Basin. This report documents the setup and calibration of the model, including the steps used to process to incorporate this data into the groundwater model.

Bedford-Coldwater GSP
Groundwater Model Report 2 TODD GROUNDWATER

2. BASIN GEOLOGY AND STRUCTURE
The following summarizes the hydrogeologic conceptual model (HCM) and groundwater conditions from the GSP (see Sections 3 and 4). The HCM and groundwater conditions create a foundation of the technical aspects of the Basin’s hydrogeology necessary for model development. This section references figure and text in Sections 3 and 4 of the GSP.

2.1. BEDFORD COLDWATER BASIN
The Basin is a subbasin of the Elsinore Basin and covers approximately 11 square miles in western Riverside County (Figure 1). The Basin is located between the Santa Ana Mountains to the west and the Perris Plain on the east. The Basin is separated from the Temescal Subbasin to the northwest by a groundwater divide near Bedford Wash. A jurisdictional boundary separates the Basin with the Elsinore Valley Subbasin to the south. The Basin is thin in some areas, which impedes groundwater flow especially at the northern and southern boundaries.

2.1.1. Physiography
Ground surface elevations along the valley floor are generally flat. Elevations range from approximately 1,000 feet above mean sea level (msl) at the northern boundary to approximately 1,200 feet above msl to the south, as shown by 200-foot contours on Figure 1. The tributary watersheds reach up to more than 5,600 feet msl at the highest peak in the Santa Ana Mountain watersheds west of the Basin.

Watersheds east of the Basin are significantly lower in elevation and rise only to about 1,800 feet.

Annual precipitation varies from below 12 inches to more than 26 inches over the Study Area. The longterm average annual rainfall is between 12 and 14 inches per year on the Basin floor and increases to more than 20 inches along the top of the local watersheds in the Santa Ana Mountains to the west.

2.1.2. Hydrology
The Basin covers a portion of the Santa Ana River watershed. Main tributaries to the Santa Ana River include Temescal Wash which flows through the Basin from the southeast to northwest and the Bedford Wash flowing toward the northeast along the northern boundary of the Basin. These waterways are ephemeral and are dry much of the year, flowing mainly during the winter. Water enters the basin as surface runoff and subsurface inflow from watersheds draining into the basin. The overall watershed tributary to the Basin was divided into 15 sub-watersheds for the purpose of simulating inflow to the model, as shown on Figure 2.

2.1.3. Management Areas
Two management areas have been designated for the Basin. These are:
• Bedford Management Area (Bedford MA) consists of the eastern areas of the Basin including Temescal Wash, and the Bedford area extends from the Elsinore Valley Subbasin to the south to the Temescal Subbasin to the north.
• Coldwater Management Area (Coldwater MA) consists of the western areas of the Basin and is more than 800 feet thick (Todd and AKM, 2008). The Coldwater Area does not share a boundary with either the Elsinore Valley or the Temescal Subbasins.

Bedford-Coldwater GSP
Groundwater Model Report 3 TODD GROUNDWATER
The Glen Ivy fault separates the Bedford area from the Coldwater area, resulting in differing geology, water use, water quality, and sources of water between the two areas. The fault offsets the aquifer units in the Bedford MA from the units in the Coldwater MA by up to approximately 250 feet (Todd, 2019), with the total basin thickness greater on the west side of the fault (Coldwater MA) relative to the east side of the fault (Bedford MA). These differences serve as the basis for defining two management areas in the Basin for the purpose of facilitating implementation of the GSP. The Bedford and Coldwater MAs will be used in the water budget analysis for the surface water and groundwater modeling results.

The Bedford MA is the area east of the Glen Ivy fault and west of the Estelle Mountain area. Alluvial sediments are up to 500 feet thick in the Bedford MA (Todd and AKM, 2008). Land uses are primarily urban residential and commercial/industrial in the Bedford MA. Temescal Wash flows from the southeast to northwest along the full length of the Bedford MA along the northern boundary of the Basin.

The Coldwater MA is the area located in a deep basin area located west the Glen Ivy fault and east of the Santa Ana Mountains. Alluvial sediments are more than 800 feet thick in the Coldwater MA (Todd and AKM, 2008). The City of Corona and Elsinore Valley Municipal Water District established a production agreement in 2008 to ensure the sustainable use of groundwater in the Coldwater area (EVMWD, 2008). Glen Ivy Hot Springs is a community water system with one well in the Coldwater MA, it is estimated the water system serves 750 people.

2.2. REGIONAL GEOLOGY
The Basin is located within one of the structural blocks of the Peninsular Ranges of Southern California.

The Basin occurs in a linear low-lying block, referred to as the Elsinore-Temecula trough, between the Santa Ana Mountains on the west and the Perris Plain on the east (Norris and Webb 1990). The trough extends from Corona to the southeast some 30 miles and was formed along an extensive northwestsoutheast trending fault zone including the Elsinore, Chino, and related faults. The Elsinore fault zone, including the Glen Ivy Fault, bound the Basin on the west and trend along the mountain front.

2.2.1. Geologic Units
The Bedford-Coldwater Basin is composed of alluvial fan, recent alluvial along Temescal Wash and older sedimentary rocks. These deposits are sourced from the Santa Ana Mountains to the west of the Basin and the Peninsular Ranges to the east of the Basin. Alluvial deposits along Temescal Wash and local tributaries define the eastern boundary of the Basin. The alluvial fan deposits in the Coldwater area extend into the Bedford area and appear to have been disrupted by faulting (GSP, Section 3, Figure 3-5).

Both older and recent alluvial fans have been deposited along the mountain front on the western edge of the Basin. Although these deposits are relatively thick, the entire unit is heterogeneous. These aquifers from less than 40 feet up to 500 feet in the Bedford area (eastern portion of the Basin) and up to 800 feet in thickness in the deepest portions of the Coldwater area (western portion of the Basin).

Alluvial thicknesses tend to increase toward the center of the basin away from the faults (MWH, 2004, Todd and AKM 2008).

Underlying much of the Basin is the Bedford Canyon Formation (a slightly metamorphosed sedimentary formation composed of interlayered argillite, slate, graywacke, conglomeratic graywacke, impure quartzite, and small masses of limestone and quartz-rich metasandstone) and adjacent granitic rocks are the primary source materials for these alluvial deposits. In the northern Bedford area, a variety of Bedford-Coldwater GSP
Groundwater Model Report 4 TODD GROUNDWATER
Tertiary sedimentary units crop out including the Silverado (Paleocene), Vaqueros (Miocene), Topanga (Miocene), and Puente (Miocene) formations (GSP, Section 3, Figure 3-5).

These uplands surrounding the Basin are composed principally of granitic, volcanic and older sedimentary rocks of Jurassic and Cretaceous age. The Coldwater MA is surrounded by the metamorphic, volcanic and granitic basement rocks of the Santa Ana Mountains to the south and west.

Around the Bedford MA is an area of sedimentary units of Tertiary age that crop out along the mountain front generally lying east of the Glen Ivy Fault within the Elsinore Fault Zone. This zone of sedimentary units broadens to the north and contains numerous mapped formations of Cretaceous and Tertiary age.

2.2.2. Faults
The Glen Ivy Fault is associated with the right lateral strike-slip-dominated Elsinore Fault Zone that extends approximately 200 km from Baja California north to the Corona area. Bedrock faulting in the area largely controls depth to bedrock and the resultant alluvial thickness (MWH, 2004). The units in the Basin are truncated by the Glen Ivy fault that separates the Bedford area from the Coldwater area.

The location and effect of the Glen Ivy fault on the units of the Basin are shown on cross sections presented in GSP Section 3 (Figures 3-6 through 3-8). As shown on these cross sections, the Glen Ivy fault and related faults offset the units approximately by as much as 250 feet. This offset is inferred from well logs that extend to bedrock near the fault. Groundwater flow in the Basin is strongly affected by the Glen Ivy fault (Todd and AKM 2008, WEI 2015b) and the fault appears to be a nearly complete barrier to subsurface flow (MWH, 2004)

2.2.3. Pull-Apart Basin
The Elsinore Fault Zone forms a complex series of pull-apart basins (Morton and Weber 2003). The deep portion of the Basin in the Coldwater MA is one of these pull-apart basins. Pull-apart basins are topographic depressions that form at releasing bends or steps in basement strike-slip fault systems. This initial deposition into the Basin is composed of rapid deposition of landslide and debris flow deposits which are extremely poorly sorted with a mixture of clay, sand, gravel and boulders as seen on the well logs at the lower depths. Since the movement on the faults is right-lateral, the oldest sediments will be located at the lower levels in the northern part of the Basin. As the pull-apart basin forms, progressively younger sediments will be deposited from north to south. Because of this type of deposition, the lower units of the pull-apart basin can be chaotic.

Pull-apart basins are topographic depressions that form at releasing bends or steps in basement strikeslip fault systems. Traditional plan view models of pull-apart basins usually show a rhombic to spindleshaped depression developed between two parallel master vertical strike-slip fault segments. The basin is bounded longitudinally by a transverse system of oblique-extensional faults, termed “basin sidewall faults” (Figure 3). Basins commonly display a length to width ratio of 3:1 (Wu et.al., 2012).

The Coldwater area of the Basin is located within a pull-apart basin between the Glen Ivy fault and the Elsinore Fault Zone located at the base of the Santa Ana Mountains. Based on the geology, the Glen Ivy fault limits deep groundwater flow, resulting in a limitation of the hydraulic connection between the Coldwater ad Bedford areas. At depth, the offset geologic units place the alluvial deposits in the Coldwater area against the Tertiary Bedford Canyon Formation. When groundwater levels in the Coldwater area are low, there is reduced groundwater flow across the fault. This is especially apparent during the recent periods when the groundwater levels in the Coldwater area were especially low.

During these low water periods in the Coldwater area, groundwater levels are higher across the fault in Bedford-Coldwater GSP
Groundwater Model Report 5 TODD GROUNDWATER
the Bedford area resulting in minor inflows from Bedford into the Coldwater area. This is shown in some recent groundwater level data (GSP Sections 3 and 4). However, at shallower depths, the fault offset is across alluvial deposits. During periods, or areas, when groundwater levels in the Coldwater area are high, groundwater elevation data suggests these areas appear to be well-connected when groundwater elevations in the Basin are high (MWH, 2004, Todd and AKM 2008), indicating more compartmentalization with depth.

2.2.4. Definable Basin Bottom
The Basin bottom is defined by bedrock, which is shallow around the perimeter and deep in the center.

Depth to bedrock ranges in depth from 10 feet to over 700 feet (Todd and AKM, 2008 and WEI, 2015b).

The depth to the bottom of the alluvial materials in the Basin and the contact with the bedrock bottom of the Basin are shown in the contours presented in GSP, Section 3 (Figures 3-9). Aquifer thickness is greatest in the Coldwater portion of the Basin west of the Glen Ivy fault. Additional cross sections showing these relationships are provided in the GSP, Section 3 (Figures 3-6 through 3-8).

2.3. GROUNDWATER CONDITIONS
Understanding the groundwater conditions is important in development of the surface water and groundwater models. A summary of the discussion of the groundwater conditions and water balance based on the model results is provided in GSP Sections 4 and 5 is provided below.

2.3.1. Aquifer
The Basin is defined by the lateral extents of the alluvial material described above. This material is bounded by bedrock in the Santa Ana Mountain on the west and the Peninsular Ranges to the east. The southern and northern boundaries of the Basin are formed by areas of thin alluvial material over shallow bedrock in narrow valleys (Todd and AKM, 2008 and WEI, 2015b). The northeastern side of the valley is flanked primarily by granitic rocks of Cretaceous age. Erosion of these units has filled in the trough over time resulting in quaternary-age alluvial fan, channel, and other deposits making up the permeable portions of the groundwater Basin (Todd and AKM, 2008). The Basin is thin in some areas, which impedes groundwater flow. This is especially relevant at the northern and southern boundaries of the Basin. With the exception of the Glen Ivy fault described above, there are no other known aquifer characteristics impeding or impacting flow in the Basin.

The Basin aquifer is truncated by the Glen Ivy Fault that separates the Bedford area from the Coldwater area. The location and effect of the Glen Ivy Fault on the units of the Basin are shown on cross sections in GSP, Section 3 (Figures 3-6 through 3-8). As shown on these cross sections, the Glen Ivy Fault offsets the units by up to 250 feet. As noted above, these faults may sometimes impede groundwater flow, backing up groundwater west of the fault within the Coldwater MA and limiting flow into the Bedford MA (Todd 2019). However, there is insufficient groundwater elevation monitoring information to assess the extent of this potential barrier to flow and it is therefore not considered a complete barrier to groundwater flow in the Basin.

2.3.2. Recharge and Discharge Areas
Recharge to the Basin occurs primarily from infiltration of runoff, and to a lesser extent from deep percolation of precipitation and urban return flows, wastewater recharge, and subsurface inflow from outside the Basin. Most of the Basin recharge comes from the infiltration of runoff from precipitation in Bedford-Coldwater GSP
Groundwater Model Report 6 TODD GROUNDWATER
the Santa Ana Mountains west of the Basin and the Peninsular Ranges east of the Basin. Large amounts of runoff from the mountains flows into unlined channels and the shallow subsurface at the edges of the Basin and then on into and through the Basin. The amount of water available for recharge varies annually with changes in rainfall and runoff. Runoff into the Basin is subject to evapotranspiration, infiltration, and continued surface flow to and in the Temescal Wash. The watersheds contributing to the Basin include multiple drainages, all of which flow across the Basin in generally east-west orientations. Wet years generate large amounts of water that exceeds the recharge capacity of the Basin (Todd and AKM 2008).

Return flows are those portions of applied water (e.g., landscape irrigation) that are not consumed by evapotranspiration and returned to the groundwater system through deep percolation or infiltration.

Return flows associated with urban, industrial, and agricultural water uses all have the potential to contribute to recharge to the Basin (Todd and AKM 2008). Discharge from wastewater treatment and subsurface inflow occur to a limited extent in the Basin. Recharge associated with wastewater is associated with discharge at the wastewater treatment facilities. Subsurface inflow occurs along the Basin boundaries. This is not considered to be a significant source of recharge to the Basin (Todd and AKM 2008).

Sand and gravel mining has been the predominant industrial land use in the southern half of the Coldwater MA, an activity that continues today. Localized sand and gravel operations are also located along Temescal Wash in the Bedford MA. In addition, berms along washes, diversions of surface water, and the presence of large gravel pits enhance groundwater recharge of runoff in Coldwater area (Todd and AKM, 2008).

Discharge from the Basin is almost entirely from groundwater pumping, evapotranspiration, and mining operations. There is some limited discharge across the northern Basin boundary with the Temescal Subbasin, but the thin alluvial material in this area limits the volume and timing of subsurface outflow along this boundary (Todd and AKM, 2008).

2.3.3. Primary Groundwater Uses
The primary groundwater uses in the Basin are municipal pumping, with limited private pumping for small water system, commercial, industrial and residential users. Groundwater use estimates are included in GSP Section 5 (Water Budget). Groundwater in the principal aquifer in the Bedford area is primarily used for non-potable municipal and irrigation water supply. The principal aquifer in the Coldwater area is mostly used for municipal water supply. Most of the pumping in this area is from wells owned and operated by the BCGSA agencies, with some additional pumping by small community water system and small commercial users. There has historically also been non-potable pumping in this area to support agricultural, recreational, small residential, and industrial water uses.

Gravel operations in the Coldwater MA extract water for industrial use to support sand and gravel mining. Their pumping amounts have ranged from about 100 AFY to 300 AFY, except for a period of increased production from 1975 through 1980 when production averaged about 450 AFY (Todd and AKM 2008).

Bedford-Coldwater GSP
Groundwater Model Report 7 TODD GROUNDWATER

3. RAINFALL-RUNOFF-RECHARGE MODEL
A rainfall-runoff-recharge model developed by Todd Groundwater was used to prepare estimates of groundwater recharge from rainfall, irrigation, bedrock inflow, and pipe leaks. It also generated the estimates of groundwater use for agricultural irrigation and flows in ungauged streams tributary to or within the basin. Several commercially available software programs were used to prepare model input and evaluate model output, such as Microsoft Excel and ArcGIS. Finally, the rainfall-runoff-recharge model and several pre-processing utility programs were developed in the Fortran 90 programming language by Todd Groundwater.

3.1. APPROACH
The rainfall-runoff-recharge model is built around a soil moisture balance of the root zone, which is simulated continuously using daily time steps for the 29-year calibration period. Numerous variables are involved in the physical processes of rainfall, interception, runoff, infiltration, root zone soil moisture storage, evapotranspiration, irrigation, shallow groundwater storage, recharge of deeper regional aquifers from shallow groundwater, and lateral flow of shallow groundwater into streams. Accordingly, the groundwater basin and tributary watersheds were divided into small recharge zones over which the most influential variables were relatively homogeneous. The daily water balance was then simulated for each zone, and the results aggregated geographically to cells in the groundwater model grid and temporally to the model stress periods.

The rainfall-runoff-recharge model provides several benefits to the groundwater modeling effort:
• It represents the hydrological processes with governing equations that reflect the actual physical processes, at least in a simplified way. This allows sensitivity or suspected errors to be traced to specific assumptions and processes.
• It enforces the principle of conservation of mass on the recharge and stream flow values.

Beginning with rainfall, all water mass is accounted for as it moves through the hydrological system.
• It allows additional data sets to be included in model calibration. In tributary watersheds with gauged stream flow data, measured flows can be compared with simulated flows, which consist of the sum of direct runoff and shallow-groundwater seepage to streams. Simulated irrigation frequency can be compared with actual grower practices, and applied irrigation amounts can be compared with water delivery data recorded by the District. Simulated urban irrigation amounts can be compared with seasonal variations in measured urban water use, which are primarily related to urban irrigation.
• It provides estimates of stream flow in ungauged tributary streams, as well as runoff from valley floor areas within the active model domain.
• It provides estimates of inflow from bedrock and/or upland areas adjacent to the active model domain and constrains the amounts of inflow according to the water balance for each tributary watershed.
• It simulates the effects of runoff from impervious surfaces in urban areas, either to storm drainage systems or to adjacent pervious soils.
• It simulates changes in land use over the 29-year calibration period and the resulting changes in recharge and irrigation demand.

Bedford-Coldwater GSP
Groundwater Model Report 8 TODD GROUNDWATER
• It combines and parses all of these flows—plus estimated recharge from leaky water and sewer pipes—into recharge values by model cell and stress period in the format required by MODFLOW.

The following sections describe the input data sets and the assumptions and governing equations used to simulate each hydrologic process included in the rainfall-runoff-recharge model.

3.2. LAND USE AND RECHARGE ZONES
Recharge zones were developed by intersecting and editing numerous maps in GIS. The starting point was a map of the Bedford-Coldwater Basin and the boundaries of all surrounding watersheds that flow into it. The Basin area was divided into the Bedford MA and Coldwater MA. The Basin and tributary watersheds were then divided into numerous polygons reflecting land use as of 1990 and changes in land use since then. Land use was delineated into 13 categories based on DWR land use maps for Riverside County from 1993 and 2000, a statewide crop map developed by LandIQ for DWR in 2014 and Google Earth historical aerial imagery available for 1990-2018. The primary change in land use has been urbanization of undeveloped (natural vegetation) areas. Polygons were delineated to represent the locations of changes in land use so that a single, fixed set of polygons could accurately represent the evolution of land use by changing the use type of a polygon beginning in the year that land use changed.

Additional divisions of polygons were made on the basis of soil texture, annual rainfall and watershed.

This resulted in a total of 224 polygons ranging in size from 2 to 4,529 acres. A map of the zones and their land uses in 1990 and 2018 is shown in Figure 4.

Land use in each zone was assigned to one of thirteen categories. The only agricultural crop in the Basin is citrus, which occupied about 1,900 acres in 1990 and was almost entirely converted to residential during the 1990s. Natural land cover categories are grassland, shrubs/trees, dense riparian, sparse riparian and open water. Developed land uses are residential, low-density residential, turf, commercial, industrial, quarry and vacant. The natural and developed land uses were mapped by inspection of Google Earth aerial photography. The categories are listed in Table 1 along with their total acreages in 1990, 2018 and 2068 (estimated) in the groundwater basin management areas and tributary watersheds.

Table 1. Bedford-Coldwater Basin Land Use (acres)
Bedford-Coldwater GSP
Groundwater Model Report 9 TODD GROUNDWATER
Each land use category is further divided into irrigated, non-irrigated and impervious subareas. These are not explicitly mapped but are expressed as percentages of total zone area. Based on examination of aerial photographs and historical water use patterns, the percent impervious cover in urban land use areas was estimated to be 15 percent for low-density residential, 45 percent for residential, 70 percent for commercial and 80 percent for industrial. The corresponding percent irrigated area for those categories was estimated to be 14, 18, 10 and 0 percent, respectively.

3.3. RAINFALL
The distribution of average annual rainfall over the basin and tributary watersheds was obtained from PRISM climate modeling (http://www.prism.oregonstate.edu/ ). Each recharge zone was assigned an average annual rainfall value based on its location, as shown in Figure 5.

The surface hydrology model requires daily rainfall as one of two transient inputs. Daily rainfall for the Elsinore station was used for this purpose, with missing values supplied by correlation with rainfall at the Riverside Fire Station and Claremont-Pomona Stations, both of which also have long periods of record. Daily rainfall for each recharge zone was calculated as Elsinore daily rainfall multiplied by the ratio of zonal average-annual rainfall to Elsinore average-annual rainfall.

3.4. INTERCEPTION
Plant leaves intercept some of the rain that falls from the sky, and the amount is roughly proportional to the total leaf area of the vegetation canopy. The estimated interception on each day of rain ranged from zero for industrial, idle and vacant land uses, to 0.03 inch for turf and 0.06 inch for trees in full leaf.

These estimates were inferred from published results of interception studies (Viessman and others, 1977). For each day of the simulation, rainfall reaching the land surface (throughfall) is calculated as rainfall minus interception. Interception storage is assumed to completely evaporate each day and is not carried over from one day to the next.

3.5. RUNOFF AND INFILTRATION
Most throughfall infiltrates into the soil, but direct runoff occurs when net rainfall exceeds a certain threshold. The threshold at which runoff commences and the percent of additional rainfall that runs off are significantly influenced by a number of variables, including soil texture, soil compaction, leaf litter, ground slope, and antecedent moisture. These factors can be highly variable within a recharge zone, and data are not normally available for them. Also, the intercept and slope of the rainfall-runoff relationship depend on the time increment of analysis. Most analytical equations for infiltration and runoff apply to spatial scales of a few square meters over periods of minutes to hours (Viessman and others, 1977).

They are suitable for detailed analysis of individual storm events. The curve number approach to estimating runoff also applies to single, large storm events. It is not suitable for continuous simulation of runoff over the complete range of rainfall intensities (Van Mullen and others, 2002). The approach used in the rainfall-runoff-recharge model is similar but less complex than the approach used in popular watershed models such as HSPF (Bicknell and others, 1997).

In the rainfall-runoff-recharge model, daily infiltration is simulated as a three-segment linear function of throughfall, and throughfall in excess of infiltration is assumed to become runoff. The general shape of the relationship of daily infiltration to daily net rainfall is shown in Figure 6 (upper graph). Below a specified runoff threshold, all daily throughfall is assumed to infiltrate. Above that amount, a fixed percentage of throughfall is assumed to infiltrate, which is the slope of the second segment of the Bedford-Coldwater GSP
Groundwater Model Report 10 TODD GROUNDWATER
infiltration function. Finally, an upper limit is imposed that represents the maximum infiltration capacity of the soil. The runoff threshold, the percentage of excess net rainfall that infiltrates, and the maximum daily infiltration capacity were assumed to vary by land use and were among the variables adjusted for model calibration. The runoff threshold ranged from 0.2 inches per day (in/d) for unpaved areas in industrial and commercial zones to 1.0 in/d for turf and natural vegetation areas. The infiltration percentage for excess rainfall ranged from 60 percent in commercial and industrial areas to 94 percent in areas of natural vegetation. The maximum daily infiltration was set to 2.5 in/d in upland tributary areas and 4 in/d for zones overlying the Basin. These values were selected on the basis of calibration, although results were not very sensitive to this parameter.

The above parameter values are for soils that are relatively dry. Infiltration rates decrease as soils become more saturated. This phenomenon led to the development of the Antecedent Runoff Condition adjustment factor for rainfall-runoff equations (Rawls and others, 1993). However, application of the concept has been focused on individual storm events. For the purpose of the rainfall-runoff-recharge model, the adjustment provides a means of simulating empirical observations that a given amount of rainfall produces less runoff at the beginning of the rainy season when soils are relatively dry than at the end of the rainy season when soils are relatively wet. This effect is included in the recharge model as a multiplier that decreases the estimated infiltration as soil saturation increases. This multiplier is applied to the runoff threshold, the infiltration slope and the maximum infiltration rate. The multiplier decreases from 1.0 when the soil is dry to a user-selected value between 1.0 and 0.60 when the soil is fully saturated (lower graph in Figure 6). A low value has the effect of decreasing infiltration (and potential groundwater recharge) toward the end of the rainy season or in very wet years, and also to increase simulated peak runoff during large storm events. The multiplier under saturated conditions was assumed to be 0.75 for the Bedford-Coldwater rainfall-runoff-recharge model.

Runoff from impervious surfaces was assumed to equal 100 percent of rainfall. Runoff that flows into a storm drain system (known as “connected impervious runoff”) contributes to stream flow but not groundwater recharge. However, runoff from some impervious surfaces flows onto adjacent areas of pervious soils (“disconnected impervious runoff”). The surface hydrology model treats this type of runoff as if it were a large increment of additional rainfall where it flows over or ponds on the pervious soils. The excess water can quickly saturate the soil and initiate deep percolation. The model incorporates this process by means of a variable representing the fraction of impervious runoff that becomes deep percolation. Data and literature values are not available for this variable. It was estimated to be 20 percent in residential, commercial and industrial areas and 80 percent in low-density residential areas.

3.6. ROOT ZONE DEPTH AND MOISTURE CONTENT
The storage capacity of the root zone equals the product of the vegetation root depth and the available water capacity of the soil. The available water capacity for each recharge zone was a depth-weighted average for the dominant soil type, as reported in the soil survey (Natural Resources Conservation Service, 2015). Root depth is a complex variable. Except for cropland, vegetation cover typically consists of a mix of species with different root depths. At a very local scale, roots are deepest directly beneath a plant and shallower between plants. Root density and water extraction also typically decrease with depth within the root zone. To complicate matters, root depth is somewhat facultative for some plants, which means that roots will tend to grow deeper in soils with low available water capacity, such as sands. Finally, root depth in upland watershed areas can be restricted by shallow bedrock.

Bedford-Coldwater GSP
Groundwater Model Report 11 TODD GROUNDWATER
The root depth selected for each recharge zone essentially represents an average of all these factors.

Simulated recharge and stream base flow are both quite sensitive to vegetation root depth, and values were adjusted during the joint calibration of the rainfall-runoff-recharge model and the groundwater flow model. Separate root depths were specified for irrigated and non-irrigated vegetation in each recharge zone. Root depths for turf and crops were required to be the same in all zones. In upland watersheds root depth can be affected by the depth to bedrock, which is often shallow. Outflow from individual tributaries flowing into the basin is not gaged, and uniform rooting depths for grass and shrubs/trees were used throughout all of the watersheds.

3.7. EVAPOTRANSPIRATION
Evapotranspiration is affected by meteorologic conditions, plant type, plant maturity, and soil moisture availability. All of these factors are included in the rainfall-runoff-recharge model. The evaporative demand created by meteorological conditions is represented by reference evapotranspiration (ETo).

Numerous equations have been developed over the years relating ETo to solar radiation, air temperature, relative humidity and wind speed. For the purposes of this study, daily values of ETo were obtained from a microclimate station in Temecula (about 20 miles south of the Basin) that is part of the California Irrigation Management Information System (CIMIS) network.

Vegetation factors are lumped into multipliers called crop coefficients. Reference ET is the amount of water evapotranspired from a broad expanse of turf mowed to a height of 4-6 inches with ample irrigation. ETo is multiplied by a crop coefficient to obtain the actual ET of a different crop or vegetation type at a particular stage in its growth and development. Although primarily used for agricultural crops, crop coefficients can also be applied to urban landscape plants and natural vegetation. The only agricultural crop in the Basin is citrus trees, which have a crop coefficient that ranges from 0.5 in winter to 0.91 in mid-summer (U.N. Food and Agriculture Organization, 2006). Irrigated landscaping was assumed to consist primarily of turf, for which a crop coefficient of 0.8 was used in all months (Snyder and others, 2007). Non-irrigated natural grassland consists of annual grasses that go dormant in summer once soil moisture has been depleted. A crop coefficient of 1.0 was assigned in all months, but actual ET decreases to zero as the grasses lower soil moisture to the wilting point in summer. Natural shrubs/trees were assigned a crop coefficient of 0.8 year-round. Those perennial species have deeper roots and do not tend to fully deplete root zone soil moisture during a single dry season (Blaney and others, 1963).

Many riparian phreatophytes are deciduous, and a crop coefficient of 0.75 was assigned for winter months to reflect a reduced leaf area index. Their tall stature and linear distribution within an arid landscape raises the crop coefficient in summer months, and a coefficient of 1.10 was assigned to reflect those factors.

3.8. IRRIGATION
Evapotranspiration gradually depletes soil moisture, and for irrigated areas the rainfall-runoff-recharge model triggers an irrigation event whenever soil moisture falls below a specified threshold. The amount of applied irrigation water is equal to the volume required to refill soil moisture storage to field capacity, divided by the assumed irrigation efficiency. An irrigation threshold equal to 70 percent of maximum soil moisture storage was used for citrus, and a threshold of 0.8 was used for urban landscaping. This variable primarily affects the frequency of irrigation; a higher threshold results in more frequent irrigation but approximately the same total amount of water applied annually. Ten percent of water applied to citrus was assumed to percolate past the root zone, and 15 percent was assumed for urban irrigation. This reflects nonuniformity of applied water, such as uneven overlap of sprinkler spray areas.

Bedford-Coldwater GSP
Groundwater Model Report 12 TODD GROUNDWATER
There are additional sources of irrigation inefficiency, such as evaporation of sprinkler spray mist and sprinkler overspray or runoff onto impervious surfaces in urban areas. Thus, total irrigation efficiency is less than 90 percent for citrus and 85 percent for urban landscaping. Total efficiency was used to estimate applied water, but only the deep percolation component was used to estimate deep percolation. Urban irrigation in the Basin is supplied by municipal water purveyors, and irrigation use is included in their metered deliveries. The rainfall-runoff-recharge model was only used to estimate groundwater pumping for citrus irrigation.

Because irrigation is assumed to completely refill soil moisture storage and is less than 100 percent efficient, simulated soil moisture exceeds capacity immediately following an irrigation event. The excess is assumed to become deep percolation beneath the root zone.

3.9. DEEP PERCOLATION FROM ROOT ZONE TO SHALLOW GROUNDWATER The surface hydrology model updates soil moisture storage each day to reflect inflows and outflows.

Rainfall infiltration and applied irrigation water are added to the ending storage of the previous day, and ET is subtracted. If the resulting soil moisture storage exceeds the root zone storage capacity, all of the excess is assumed to percolate down from the root zone to shallow groundwater on that day. In modeling parlance, this is known as a “bathtub model”; vertical unsaturated flow and preferential flow through cracks and root tubes in the soil are not considered.

3.10. MOVEMENT OF SHALLOW GROUNDWATER TO DEEP RECHARGE AND

STREAM BASE FLOW
A shallow groundwater storage component may not be part of all groundwater systems, but its presence is sometimes indicated by groundwater hydrographs and stream base flow. In upland watersheds, for example, the shallow groundwater reservoir is what supplies base flow to streams.

Without it, simulated stream flow consists of large flows occurring only on rainy days. Physically, it represents the overall permeability and storage capacity of deep soil horizons and bedrock fractures beneath hillsides bordering a gaining stream. It allows the integration of shallow and deep, fast and slow flow paths between the point of rainfall infiltration and the stream. In valley floor areas with flat terrain and deep deposits of unconsolidated basin fill, the presence of a shallow groundwater system is sometimes evident in a lack of response of deep well hydrographs to rainfall recharge events or even wet versus dry years. The shallow zone in that case attenuates the pulses of recharge percolating beneath the root zone into a relatively steady recharge flux, and there may be little outflow to streams.

In the surface hydrology model, the only inflow to shallow groundwater storage is deep percolation from the root zone. There are two outflows: laterally to a nearby creek and downward to the regional groundwater flow system. Outflow to streams is specified as a certain percentage of current groundwater storage, which results in a first-order logarithmic recession of stream base flow, consistent with gaged stream flows. Outflow to the regional groundwater system is simulated as a constant downward flux. This is consistent with flow across confining layers in which the vertical head gradient is near unity. Both outflows are calculated and subtracted from shallow groundwater storage each day.

They continue until the storage has been exhausted, resuming whenever a new influx of deep percolation from the root zone arrives. There is no assumed maximum capacity of shallow groundwater storage.

The two parameters defining shallow groundwater flow are the recession constant for flow to streams and the constant downward flow rate for deep recharge. Both of these are obtained by calibration. The Bedford-Coldwater GSP
Groundwater Model Report 13 TODD GROUNDWATER
recession constant can generally be calibrated by matching simulated to measured stream base flow in gaged watersheds. The deep recharge rate can be used to adjust the long-term partitioning of shallow groundwater mass into base flow versus recharge.

The shallow groundwater component of the surface hydrology model is simple but adequate to capture the fundamental behaviors of logarithmic stream base flow recession and attenuated deep recharge.

Other watershed models invoke more complex systems of storage and flow to simulate these processes.

For example, the Precipitation and Runoff Modeling System (PRMS) developed by the U.S. Geological Survey includes a total of seven storage components between the point where a raindrop reaches the ground and the stream into which it ultimately flows (Markstrom and others, 2015). This larger number of components and parameters enables relatively detailed matching of observed stream flow hydrographs but is unnecessarily complex for the purposes of groundwater modeling.

3.11. EVAPOTRANSPIRATION BY RIPARIAN VEGETATION
In locations where the water table is shallow, some plants (phreatophytes) can extract water directly from the water table to meet evaporative demand. The rainfall-runoff-recharge model was used to estimate the amount that would be drawn from the water table if a shallow water table were present.

The potential use of groundwater by phreatophytes was assumed to equal the ET demand of the vegetation minus the amount that could be supplied by soil moisture. In practice, this was accomplished by temporarily simulating the vegetation as if it were irrigated using the rainfall-runoff-recharge model, then using the simulated irrigation rates as the maximum rate of withdrawal by roots from the water table. This rate of groundwater use is thought to decrease with increasing depth to the water table because fewer shrub and tree roots are able to reach the water table and the energetics of withdrawing the water become less favorable. The use of groundwater decreases from the maximum rate when the water table is at the land surface to zero when the water table is 15 feet or more below the ground surface. These calculations are applied at model cells where aerial photographs indicate the presence of dense, lush riparian vegetation, which is a sign of phreatophytic water use. These calculations were also made using the MODFLOW evapotranspiration (EVT) module.

3.12. GROUNDWATER INFLOW
Groundwater inflow into the basin from adjacent uplands—also called mountain front recharge—is difficult to estimate. If the basin is bounded by igneous or metamorphic rocks with very limited groundwater flow through fractures, it can be reasonable to assume that inflow from bedrock is negligibly small. If the bedrock is fractured, the total amount of inflow across the long “no-flow” boundaries on the east and west sides of the Basin can be cumulatively significant. Subsurface inflow across those boundaries was estimated using the rainfall-runoff-model results for the tributary watersheds. By this method, the estimates must be consistent with conservation of mass in the watersheds; that is, with the estimates of rainfall, ET, and surface outflow. The resulting estimates are still highly uncertain, however, because groundwater outflow from the watersheds—and surface outflow, too, for that matter—are both small compared to the two largest flows in the watershed water balances: rainfall and evapotranspiration. Thus, a small error in the estimate of either of those flows can result in a large error in groundwater outflow.

Ultimately, groundwater flows produced by the rainfall-runoff-recharge model were calibrated based on their effects on simulated groundwater levels at nearby wells within the basin and on the simulated amount of stream base flow exiting the watersheds. The initial groundwater inflow estimates were generally too high. The estimates were lowered primarily by increasing the estimated root depth of Bedford-Coldwater GSP
Groundwater Model Report 14 TODD GROUNDWATER
natural vegetation in the watersheds, which is highly uncertain due to the effects of shallow bedrock on rooting depth.

Groundwater inflow from tributary watersheds was smoothed over time to reflect attenuation of recharge pulses that occur during wet months and wet years as they gradually flow through long, relatively slow flow pathways. Smoothing was accomplished by a moving average of simulated groundwater recharge in the tributary areas over the preceding 2-10 years. This range represents local variability that was indicated by rates of recession in stream base flow and groundwater levels near the basin boundary during prolonged droughts. The final estimate of average annual groundwater inflow during the calibration period was 5,400-7,200 AFY under normal climatic conditions.

3.13. CALIBRATION OF RAINFALL-RUNOFF-RECHARGE MODEL
Parameters in the rainfall-runoff-recharge model were jointly calibrated with the groundwater model.

The total amount of dispersed recharge and annual variations in recharge influence simulated groundwater levels, and parameters in the rainfall-runoff-recharge model were adjusted to improve the fit between measured and simulated groundwater hydrographs. The rainfall-runoff-recharge model was also calibrated based on a comparison of measured and simulated daily stream flow at two gage locations: Coldwater Canyon Creek and Temescal Wash at the Lee Lake dam. Coldwater Canyon Creek flows into the adjacent Bedford-Coldwater Basin and is the only gaged stream draining the eastern slopes of the Santa Ana Mountains. Characteristics and model parameters for that watershed were assumed to also apply to similar watersheds along the western edge of the Basin. Unfortunately, the gage began operation in 2019, which is after the 1990-2018 model simulation period. Nevertheless, the general pattern of flow peaks and base flow recession simulated in prior years was similar to the gaged pattern in 2019-2020, as shown in Figure 7.

Bedford-Coldwater GSP
Groundwater Model Report 15 TODD GROUNDWATER

4. NUMERICAL GROUNDWATER MODEL DEVELOPMENT
The numerical model incorporated the hydrogeological data from the basin and hydrologic model and is capable of simulating historical and future conditions. The following section describes the development of each of the components in the MODFLOW model.

4.1. GENERAL APPROACH
The Bedford-Coldwater Model is a numerical groundwater model, which is a mathematical description of the hydrogeological conceptual model (Bear and Verruijt, 1987). The advantage of a numerical model is that, once in a mathematical format, the model quantitatively combines data on basin geometry, aquifer properties, recharge, and discharge to simulate changes in groundwater elevations and calculate the water balance over time.

The Bedford-Coldwater Model is setup to represent the physical features that influence groundwater flow including the geology, hydrology and climate. Each of these features is mapped onto a model grid that represents the vertical and horizontal distribution of parameters over the Basin based on the hydrogeological conceptual model. The parameters can also be varied through time over a defined base period to represent seasonal variations in precipitation, streamflow and groundwater pumping. A more detailed discussion of how each of these parameters was developed and entered into the BedfordColdwater Model is summarized below. • Model Setup - representation of the physical groundwater basin • Boundary Conditions – representation of the inflows and outflows from outside of the model • Aquifer Properties – representation of the flow characteristics of the aquifer • Initial Conditions – representation of groundwater conditions prior to the model period The model development was focused on the HCM with emphasis on defining boundary conditions and flow paths. Aquifer parameters were assigned on a subregional basis within each MA and varied by model layer to represent reasonable aquifer properties for the geologic unit being simulated.

4.2. MODEL SETUP
The model also incorporates spatial distribution of the physical features of the Basin and the temporal distribution of time-varying parameters such as precipitation and recharge. The following describes the basic components required to construct a numerical model.

4.2.1. Model Code Selection
The model setup utilizes the MODFLOW modeling code developed by the United States Geological Survey (USGS). The Bedford-Coldwater Model uses MODFLOW-NWT (Niswonger et al, 2011), which is a standalone version of MODFLOW-2005 (Harbaugh, 2005) that includes an advanced mathematical solver that provides a more robust solution to complex conditions such as rewetting of dry model cells, unconfined conditions and groundwater-surface water interactions. These features improve the ability of the Model to evaluate complex groundwater-surface water interactions, potential conjunctive use, and other projects to increase future groundwater levels in the Basin.

Bedford-Coldwater GSP
Groundwater Model Report 16 TODD GROUNDWATER

4.2.2. Base Period
The update Bedford-Coldwater Model is setup using water years that run from October through to the following September to capture the cause and effect relationship on groundwater levels of wintertime rain and subsequent summertime groundwater pumping. The model simulates the 29-year base period from October 1989 through September 2018 to represent Water Years (WY) 1990 through 2018. This retains the starting date of prior models, which coincides with the beginning of some key data sets and also the beginning of the period of rapid land use conversion from agricultural to urban. The ending year is the most recent year for which all necessary model input data were available. The 29-year simulation period is desirable for model calibration purposes because it includes a wide range of hydrologic and water use conditions, including wet periods, droughts, changes in groundwater pumping and implementation of lake management measures.

To simulate this base period, the model is subdivided into time intervals termed stress periods. For each water year, monthly stress periods were defined to provide the ability of the model to evaluate temporal at a monthly scale. For the base period, a total of 348 stress periods were defined. Timedependent parameters, such as groundwater pumping or precipitation recharge, are assigned to for each stress period.

Conditions during the stress period are constant, but parameters can be varied from stress period to stress period. A stress period can be subdivided into shorter time periods, or timesteps, to allow for more temporal resolution within each stress period to help with model convergence. For the BedfordColdwater Model, each stress period was simulated using three (3) timesteps. MODFLOW calculates the groundwater elevations and water balance for each time step. The model results provide the groundwater elevations for the final timestep of each stress period, and the summation of the water balance changes for all timesteps for each stress period.

4.2.3. Model Domain and Grid
MODFLOW requires the application of a rectangular grid that encompasses the entire area, or domain, that will be modeled. The model grid forms the mathematical framework for the model. Each grid cell has to be populated with aquifer properties. Physical features such as streams and wells are mapped onto the model grid. Using this information, the MODFLOW model calculates a groundwater elevation at each model grid cell for each timestep. The density of model grid cells is what defines the resolution of the model in resolving drawdown and other hydrologic effects.

The Basin covers about 11 square miles of the Santa Ana River Watershed that underlies the Elsinore Valley in western Riverside County. The extent of the model domain for the Bedford-Coldwater Model is shown on Figure 8. The Basin has two management areas that are defined within the model domain for water budget zone budgets (Figure 9). These include:
• Bedford Management Area (Bedford MA) occupies roughly the eastern two-thirds of the Basin.

It is separated from the Coldwater MA by the Glen Ivy Fault, which is a partial barrier to groundwater flow. The Bedford MA connects to the Elsinore Subbasin in the south and the Temescal Basin at the north end of the Basin.,
• Coldwater Management Area (Coldwater MA) is the part of the Basin west of the Glen Ivy Fault. Because of downward movement on that side of the fault, Basin thickness is much greater than in the Bedford MA. A large open-pit mine is located in the southern part of this MA. Several streams enter the Coldwater MA from watersheds on the eastern slopes of the Santa Ana Mountains.

Bedford-Coldwater GSP
Groundwater Model Report 17 TODD GROUNDWATER
The Bedford-Coldwater Model consists of 250 rows, 365 columns and 3 layers. The rows and columns have a uniform spacing of 100 feet. Each 100-foot square represents a model cell. MODFLOW calculates one groundwater level for the center point of each grid cell for each timestep. The total number of grid cells in the Bedford-Coldwater Model is 273,750 cells, of which 87,882 are active cells where MODFLOW calculates a groundwater levels. The active areas represent the area within the groundwater basin where groundwater elevations are simulated.

Areas outside of the Basin are represented as no-flow cells where MODFLOW does not perform calculations. The high percentage of no-flow cells in the model grid is due to both the elongate shape of the Basin, the inclusion of narrow watersheds off of the main Basin, and because the distribution of active cells varies from layer to layer. The bottom of the lowest model layer is a no-flow boundary condition, representing the older bedrock formations that are assumed to be relatively impermeable.

4.2.4. Model Layers
The model layers represent the geologic the geologic units that compose the Principal Aquifer of the Basin based on the geology and HCM presented in summarized in Section 2. Model layers provide vertical resolution for the model to simulate variations in groundwater elevation, aquifer stresses, and water quality with depth. The model layers are based on an evaluation of the following data sets:
• Surficial geology,
• Faulting,
• Lithologic borehole logs.
• Well construction logs, and
• Previously completed local hydrogeologic conceptualizations and cross sections.

This information was collected and translated into a unified GIS compatible database structure for cross section construction and geographic evaluation. This approach allows any hydrostratigraphic structures relevant to groundwater flow in the Basin to be easily translated from GIS for use in other formats.

For the Bedford-Coldwater Model, three model layers were defined to simulate hydrogeologic character of the primary water-bearing sediments within the groundwater basin. The model layers are numbered from 1 through 3 from top to bottom. The top of Model Layer 1 represents the topography that is based on topographic elevation points every 10 meters were extracted from the National Elevation Dataset (http://ned.usgs.gov) throughout the model domain Figure 10.

The model layers represent the geologic units within each of the hydrologic areas. Figures 11 through 13 show the areal extent and thickness of each of the model layers over the entire model domain.

Figures 14 and 15 show cross sections of the model grid along row 127 and column 230, respectively, to illustrate the shapes and relative thicknesses of the layers. The following provides a summary of the geologic units represented by each model layer in accordance with the HCM for the three hydrologic areas.

In the Bedford MA, three model layers were defined that represent the following geologic units:
• Model Layer 1 – Temescal Wash alluvium and shallow soils • Model Layer 2 – Tertiary sedimentary units primarily the Bedford Canyon Formation • Model Layer 3 - Weathered bedrock
The alluvium along Temescal Wash is the primary water supply unit in the Bedford MA (Todd and AKM 2008) where the larger wells are completed. The alluvial deposits are a mix of interlayered gravels, sands, silts, and clays resulting from alluvial fan and fluvial processes. Model Layer 1 ranges up to 80 feet Bedford-Coldwater GSP
Groundwater Model Report 18 TODD GROUNDWATER
thick along the Temescal Wash. Alluvial aquifer materials are present in other parts of this hydrologic area, but their extent and production capacity are uncertain. In these areas, Model Layer 1 represents a relatively thin layer, with a minimum thickness of five feet, that overlies the Bedford Canyon Formation that is rarely saturated.

Model Layer 2 represent the Bedford Canyon Formation that is composed of alternating slate and finegrained sandstone, underlies alluvial deposits in this hydrologic area and is generally less than 200 feet deep (Todd and AKM 2008). It is reported to have limited groundwater production potential (Todd and AKM 2008). The bottom of Model Layer 2 is defined based on depth to bedrock data in the Bedford MA that ranges from 25 feet to approximately 500 feet (Todd and AKM 2008). Model Layer 3 represents the weathered and fractured bedrock formations underlying Model Layer 2. These basement rocks have limited produce significant groundwater except in fractures (Todd and AKM 2008).

In the Coldwater MA for the areas outside of the deep basin area that are upgradient of the Wildomar and Glen Ivy Faults, three model layers were defined that represent the following geologic units:
• Model Layer 1 – Coldwater Basin alluvial fill sediments. • Model Layer 2 - Older Alluvial deposits
• Model Layer 3 - Weathered Bedrock
The alluvium (both young and old) that fills the deep basin in the Coldwater Basin, represented by Model Layers 1 and 2, forms the majority of the Basin aquifer. These alluvial deposits may be more than 800 feet thick locally and are composed of interfingered gravels, sands, silts, and clays (MWH 2004, Todd and AKM 2008). Groundwater is generally unconfined in these aquifer units.

Model Layer 3 represents the weathered and fractured bedrock formations underlying Model Layer 2.

Domestic wells competed along the margins and along the narrow canyons that extend from the main part of the groundwater basin are completed in weathered bedrock. Model Layer 3 is represented by a uniform thickness of 75 feet in the weathered bedrock based on well logs of domestic wells along the basin margin.

4.2.5. Faults
The Basin is dominated by the Glen Ivy Fault zone that forms a partial barriers to groundwater flow in the between the Bedford and Coldwater MAs based on water level differences and on analysis of sources of groundwater recharge across the fault (MWH 2004, Todd and AKM 2008). The location of the faults applied for the Bedford-Coldwater Model are shown on Figure 16. For the Bedford-Coldwater Model, all faults extended across Model Layers 1 through 3.

The faults were simulated using the Horizontal Flow Boundary (HFB) Package in MODFLOW that allows by defining a conductance parameter to be placed between adjacent model cells that can act to limit groundwater flow. All of the faults were simulated as a 10-foot wide zone. The lowest fault hydraulic conductivities were applied for the faults bordering the Back Basin where the hydraulic conductivity ranged from 0.0001 to 0.00001 ft/d. The fault hydraulic conductivities were based on an initial estimate that was refined during model calibration.

4.2.6. Aquifer Conditions
Groundwater conditions for each model layer can be defined as unconfined, fully-confined, or convertible between confined and unconfined based on the relation of the simulated groundwater level to the top of the model layer. Unconfined conditions exist when groundwater levels are below the top Bedford-Coldwater GSP
Groundwater Model Report 19 TODD GROUNDWATER
of the physical aquifer layer whereas confined conditions exist when groundwater levels are above the top of the physical aquifer layer. For the Bedford-Coldwater Model, Model Layer 1 is defined as unconfined. Model Layers 2 and 3 are defined as convertible between confined and unconfined conditions.

Because of the historical changes in groundwater levels, areas within the Basin can be temporarily unsaturated. Prior MODFLOW versions set a dewatered cell to a no-flow condition for the rest of the simulation if the cell is dewatered. An important advantage of using MODFLOW-NWT compared to previous MODFLOW versions is that groundwater heads will be calculated for dry cells, whereas standard MODFLOW excludes these calculations (Niswonger et. al., 2011). This resaturation capability of MODFLOW-NWT was utilized for the Bedford-Coldwater Model.

In MODFLOW-NWT, cells can be reset to active using the rewetting option without setting a dewatered cell to no flow condition. MODFLOW-NWT will calculate a head in a dry cell while not allowing water to flow out of a dry cell that provides a continuous solution for groundwater flow. Inflow to a dry cell, either from adjacent cells, overlying cells, or an external source simulated by one of the stress packages, automatically flows downward to an underlying cell if there are deeper layers. A cell with head below the cell bottom has no water in storage, so changes in storage also are zero for these cells. The model accounts for this situation by setting the storage coefficient for a dry cell to zero. This allows for the continuous solution of head not to affect the overall water balance results (Niswonger et. al., 2011).

Because groundwater heads are calculated for dry cells using this approach, it is necessary for the model user to interpret the head in a cell relative to the cell bottom. If the head in a cell is at or below the cellbottom altitude, then the water table is not contained within this cell (Niswonger et. al., 2011).

4.3. BOUNDARY CONDITIONS
Model boundary conditions represent the hydrologic budget by simulating where groundwater enters and exits the basin. Boundary condition data must be entered for each stress period at each model grid cell where a boundary condition is defined in the model. MODFLOW NWT provides a number of boundary condition options to numerically represent the different physical processes included in the hydrologic budget. The physical distribution and volumes of groundwater inflow and outflow for each budget component needs to be accounted for geographically within the model domain. A discussion of each boundary condition of the groundwater budget is provided below.

4.3.1. Surface Recharge
The surface recharge includes the contributions from precipitation and return flows within the BedfordColdwater Model. The surface recharge is applied using zones that are defined by the geology and land use. Surface recharge is applied using the MODFLOW recharge package and using the methods outlined below. This summary discusses implementation of surface recharge into the Bedford-Coldwater Model.

4.3.2. Streams
The groundwater model dynamically simulates groundwater recharge from stream percolation and groundwater discharge into streams. Percolation from streams is a function of stream flow and—where the water table is equal to or higher than the stream bed elevation—the difference in water level between the creek and water table.

Bedford-Coldwater GSP
Groundwater Model Report 20 TODD GROUNDWATER
The MODFLOW stream flow routing (SFR2) package is used to simulate these processes. Each stream in the basin is simulated as a sequence of reaches, each of which is a model grid cell along the alignment of the channel. Flow is specified at the upstream end of each stream segment and routed down the reaches, with flow to or from the aquifer calculated on the basis of wetted channel area, channel bed hydraulic conductivity and the difference in elevation between the stream surface and the simulated groundwater level at that reach. By this means conservation of mass is applied concurrently to the stream and the aquifer. Streams can dry up completely as they cross the basin; and conversely, groundwater discharge can create stream flow in a segment that is dry farther upstream. The stream flow routing module allows for a network of channel segments, with multiple inflows or diversions at the start of each segment.

The Bedford-Coldwater Model includes a network of 43 stream segments containing a total of 1,363 stream reaches (Figure 17). Twenty-two segments are used to simulate eleven streams that drain watersheds in the Santa Ana Mountains along the west side of the Basin. Streams that flow across the Coldwater MA onto the Bedford MA where they connect up with Temescal Wash are divided into multiple segments to represent varying underlying geologic conditions. Temescal Wash is composed of thirteen segments that represent reaches along Temescal Wash. Five segments represent the short sections of five streams that drain watersheds in the Estelle Mountain and other upland areas east of Temescal Wash. Three segments represent internal drainage within the Basin the receive valley floor runoff in the northern Bedford MA.

In general, most stream reaches are more than 20 feet above the water table and are not hydraulically coupled to groundwater. Percolation from those reaches is independent of groundwater levels and not affected by pumping. Reaches where groundwater appears to be hydraulically coupled to surface water primarily include most of the length of Temescal Wash, and the lower ends of some larger tributaries as they approach the wash. All streams in the Coldwater MA are detached from the groundwater except for limited areas in the small canyons along the western basin margin.

Stream bed permeability was estimated by model calibration. Calibrated values ranged from 0.1 to

1.0 feet per day (ft/d). The relationships of stream width and depth to stream flow were divided into two categories. For small tributary streams, the relationships were patterned after measured data at the Coldwater Canyon gage. Inflows for Temescal Wash are coordinated with output from the Elsinore Valley numerical model and the USGS gauge located downstream of Lee Lake just south of the basin boundary with the Basin.

To develop estimates of surface and subsurface inflows from these tributary areas to the groundwater basin, a rainfall-runoff-recharge model is used to simulate the entire watershed tributary to the Basin.

This model simulates all near-surface hydrologic processes, including rainfall, runoff, infiltration, evapotranspiration, effects of impervious areas and irrigation, soil moisture storage and percolation to stream base flow and deep groundwater recharge. The calculated runoff is included in the SFR2 Package.

4.3.3. Mountain Front Recharge
Groundwater inflow into the basin from adjacent uplands—also called mountain front recharge—were calculated by the rainfall-runoff-recharge model (see Section 3). Mountain front recharge represents subsurface inflow of groundwater from the low-permeability rocks adjacent from the surrounding watershed to the groundwater Basin. the MODFLOW General Head Boundary (GHB) package was applied along the basin margin in Model Layer 3 which represents the weathered bedrock. The distribution of the GHB cells is shown on Figure 18.

Bedford-Coldwater GSP
Groundwater Model Report 21 TODD GROUNDWATER
The GHB package is a head dependent boundary condition; therefore, the amount of groundwater flowing into or out of this boundary was influenced by the relative hydraulic gradient between the basin and the boundary condition. To have the GHB package input the bedrock inflows determined by the rainfall-runoff-recharge model (see Section 3), the GHB was set up to act as a rate limited flux boundary.

To do this, the reference head was a considerable distance away (one mile) from the recharge location, so it is well above the groundwater levels in the model. The conductance and elevation terms for the GHB package were back-calculated to get the appropriate flux. By setting the head at distance, the variability due to the changing heads in the groundwater model produces a variation of 1 to 2 percent in the GHB flux compared to the rainfall-runoff-recharge model values. The advantage of this approach is that the bedrock inflow can more easily be distributed to a large number of cells along the basin margin to maintain simulation stability. In addition, this approach allows the Bedford-Coldwater Model to simulate a consistent groundwater gradient flowing away from the margins to be consistent with the HCM.

4.3.4. Evapotranspiration
Evapotranspiration (ET) represents groundwater outflow from evaporation to the atmosphere and uptake by plants from the saturated zone. This is distinct from ET associated with soil moisture before it reaches the groundwater aquifer that is sustained by the total available precipitation not accounted for by runoff or recharge (see Section 3).

The MODFLOW Evapotranspiration (EVT) package is used simulate ET directly from the groundwater aquifer. ET is defined over the entire model domain; however, ET only occurs in areas of shallow groundwater. In the Basin, this is generally limited to riparian areas adjacent to streams. ET includes uptake from both phreatophytes (plants that require groundwater) and mesophytes (plants that can utilize groundwater) either directly from the saturated zone or from the overlying capillary fringe (Meinzer, 1927; Robinson, 1958; and Lewis and Burgy, 1964). ET from the capillary fringe is replenished with groundwater from the underlying aquifer, so it is also considered a loss of groundwater (Lubczynski, 2011).

The MODFLOW EVT package that the ET rate decreases with increasing depth to the water table because fewer shrub and tree roots are able to reach the water table and the energetics of withdrawing the water become less favorable. In the groundwater model, the consumptive use of groundwater due to ET decreases from the maximum rate when the water table is at the land surface and diminishes linearly down to zero when the water table reaches the extinction depth for that location.

In the Bedford-Coldwater Model, three ET zones were defined as shown on Figure 19. The first zone represents locations where aerial photographs indicate the presence of dense, lush riparian vegetation indicates areas of shallow groundwater where the plants (phreatophytes) can regularly uptake water directly from the water table to meet evaporative demand. These occur along the Temescal Wash and in the upper portions of some of the canyons along the basin margin. The extinction depth for these locations was set at 15 feet below the ground surface. Over most of the remaining model domain, the extinction depth was set at 7.5 feet to represent the vegetation in these areas. The third area represents areas where quarry lakes exist where the extinction depth was set at 3.0 feet to represent evaporation off of ponded water that periodically exists in these quarry areas. ET rates applied in the BedfordColdwater Model use the ET data from the rainfall-runoff-recharge model (see Section 3).

Bedford-Coldwater GSP
Groundwater Model Report 22 TODD GROUNDWATER

4.3.5. Groundwater Pumping
Groundwater pumpage is the most significant groundwater outflow component for the basin.

Groundwater users in the Basin are required to report their pumping to Western Municipal Water District, which is one of several agencies responsible for administering adjudication decrees in the Upper Santa Ana River Watershed area. Thirty-eight wells within the Basin produced groundwater in one or more years during 1990-2018, and the reported annual pumping amounts were obtained from WMWD.

Figure 20 shows the locations of pumping in the Basin. Locations of agricultural pumping are distributed based on the estimated agriculture pumping requirements calculated using the rainfall-runoff model (Figure 21).

Annual production by all of the wells generally increased from 1990 to about 1999; however, from 2000 through 2007 annual production stabilized at about have the 1990-1999 rates, as shown in Figure 22. All pumping wells are included as analytical elements that are simulated by the MODFLOW well package in the model. Table 2 presents the overall trend in average annual groundwater pumping over time along with the assigned model layer for each well. In 2008, the City of Corona and Elsinore Valley Water District came to an agreement to limit groundwater pumping The citrus groves in the Basin were presumed to be irrigated by groundwater, although that pumping does not appear to be included in the WMWD production records. The amount of irrigation was estimated using the rainfall-runoff-recharge model and was assigned to hypothetical well locations at the center of each citrus recharge polygon. Some rural residences might be served by on-site domestic wells. The amount of pumping at those wells is assumed to be negligibly small in the context of the overall groundwater budget. Small domestic wells are not included in the WMWD database and are not included in the model.

4.3.6. Recycled Water Recharge Ponds
Reclaimed wastewater is percolated in ponds at the TVWD Water Reclamation Facility (WRF) (Figure 23). However, most of the reclaimed water is recycled for irrigation. Annual or monthly data describing the partitioning of reclaimed water into irrigation, pond percolation and discharge to Temescal Wash were obtained from TVWD and the City of Corona.

Discharges from the TVWD Water Reclamation Facility (WRF) to Temescal wash were discontinued in 2013. All of the plant outflow is recycled for irrigation during spring, summer, and fall (assumed April through November), and most or all of it is percolated in ponds at the WRF when irrigation demand is low (December through March). In recent years more of the outflow from the TVWD WRF has been percolated in ponds than has been recycled for irrigation. This proportion was assumed to reverse, such that all outflow would be recycled for irrigation during April through November and all would be percolated in ponds during November through March.

The MODFLOW Well Package was used to simulate recharge at the WRF recharge ponds. The wells were simulated as recharge wells. The volume of flow was distributed evenly over the area of the ponds. Prior to 2008, the recycled water recharge was applied to recharge located just south of the TVWD WRF.

Starting 2008, recycled water recharge was applied to new recharge ponds located just north of the TVWD WRF. The simulated recharge locations are shown on Figure 24.

4.3.7. Quarries
Sand and gravel mining has been the predominant industrial land use in the southern half of the Coldwater MA, an activity that continues today. Localized sand and gravel operations are also located Bedford-Coldwater GSP
Groundwater Model Report 23 TODD GROUNDWATER
along Temescal Wash in the Bedford MA (Figure 23). In addition, berms along washes, diversions of surface water, and the presence of large gravel pits enhance groundwater recharge of runoff in Coldwater area (Todd and AKM, 2008).

Discharge from the Coldwater MA quarry operations is from groundwater pumping, evapotranspiration, and other mining operations (MWH, 2004, Todd and AKM 2008). Losses also occur when the sand and gravel from the gravel pits, which contains groundwater used for washing, is transported from the Coldwater Basin. The estimated losses from gravel operations range from about 300 acre-feet per year (ft/yr to more than 900 acre-ft/yr (MWH, 2004). The average losses are approximately 700 acre-ft/yr (MWH, 2004). Quarry outflows were simulated using a combination of the EVT and Drain Packages. The ET rate and drain conductance were varied during model calibration to simulate the average annual losses from the MWH (2004) report that are listed above. The location of the boundary conditions for the Coldwater MA quarry operations are shown on Figure 24.

Quarry recharge represents inflows of surface water into existing quarries where it is allowed to recharge into the groundwater. In the Coldwater MA, streamflow from Mayhew Creek and some other smaller streams are directed into existing quarry areas where the water is contained and allowed to percolate. Coldwater Creek has been redirected around an existing quarry. Although Coldwater Creek is not currently directed into a quarry, there have been historic instances where flood flows have gone into the quarries, especially prior to 2005. A portion of the estimated streamflow from the rainfallrunoff-recharge model for each stream is recharged to groundwater at the quarry location. This recharge from streamflow directed into the quarries is simulated using the MODFLOW well package. A portion of the monthly streamflow assigned from the rainfall-runoff model was moved from the SFR2 Package to the Well Package to simulate quarry inflow recharge.

In the Bedford area, the Mobile Sand quarry located just north of the Temescal WRF is open to potential outflows to Temescal Wash. To estimate groundwater outflows from the quarry pit during high groundwater levels, the MODFLOW model applies a boundary condition based on the observed water level in the pit to estimate the volume of quarry outflow. This is a head-dependent boundary condition that is able to calculate either quarry recharge or outflow based on groundwater conditions. This was simulated using the MODFLOW river package. Since we can estimate the water surface based on topography, the River Package can allow the quarry pit ponds to alternative from recharge to discharge based on monthly hydrologic conditions.

Quarry recharge in the Bedford MA is from streamflow from Brown and McBride Creeks flow into the Mobile Sand quarry located just north of the TVWD WRF. In addition, streamflow from Temescal Wash can flow into the quarry location especially during high and flood flows. The quarry pit at this location is below the water table and is consistently flooded. To estimate the recharge, the MODFLOW model applies a boundary condition based on the observed water level in the pit to estimate the volume of quarry recharge. Similar to the Coldwater MA quarry recharge, recharge from streamflow directed into the quarries is simulated using the MODFLOW well package. A portion of the monthly streamflow assigned from the rainfall-runoff model was moved from the SFR2 Package to the Well Package to simulate quarry inflow recharge.

4.3.8. Subsurface Flow with Adjacent Groundwater Basins To simulate potential subsurface groundwater and outflow with adjacent groundwater basins, a specified head boundary was defined using the MODFLOW constant head package. Constant head boundaries allow sufficient inflow or outflow at that model cell to achieve the specified head. Where the Bedford-Coldwater GSP
Groundwater Model Report 24 TODD GROUNDWATER
Basin adjoins the Elsinore Valley and Temescal Basins, at the north and south ends of the model respectively, represent a very small percentage of the overall perimeter of the Basin.

Along the Elsinore Subbasin boundary, a constant head boundaries were set along a limited length of the boundary near Temescal Wash and another unnamed stream (Figure 24). The constant head along Temescal Wash was set at 1046.5 feet in Model Layer 2 and 3. Along the unnamed stream, the constant head was set at 1068.0 feet in Model Layer 2 and 3.

Along the Temescal Subbasin boundary, a similar set of constant head boundaries were set along a limited length of the boundary near Temescal Wash and another unnamed stream (Figure 24). The constant head along Temescal Wash was set at 765.0 feet in Model Layers 1, 2 and 3 for the first three years, and then set to 775.0 feet for the following twenty-six years. The constant head boundaries were based on an initial estimate that was refined during model calibration.

4.4. AQUIFER PROPERTIES
Aquifer properties represent the physical and hydrogeologic characteristics of the aquifers within the Basin that control groundwater flow. Aquifer properties must be assigned to each active grid cell in the model. The conceptual model provides the framework necessary to define aquifer properties.

4.4.1. Aquifer Characteristics
The groundwater model represents the basin fill materials in terms of their ability to store and transmit groundwater. Horizontal and vertical hydraulic conductivity define the permeability of the aquifer, which is its ability to transmit groundwater flow. The ability to store water consists of two components.

At the water table, storage of water associated with filling or draining the empty (air-filled) interstices between mineral grains is represented by the specific yield of the aquifer. In deep aquifers, there is a much smaller ability to store and release groundwater that derives from the compressibility of the water and aquifer materials (specific storativity). Thus, the initial response to pumping from a deep aquifer is a large drop in water level (head) within that aquifer. With sufficient time, however, the decrease in head creates downward movement of groundwater that eventually accesses the storage capacity at the water table. In other words, the storage response of the aquifer depends partly on the duration of pumping and observation. For groundwater management purposes, storage responses over periods of months to decades are usually the most relevant.

Aquifer characteristics can be estimated in two ways. The first is by means of an aquifer test in which one well is pumped while water levels are measured at a nearby well. This approach typically measures horizontal hydraulic conductivity over distances of tens to hundreds of feet and storage responses over periods of 1-3 days. The second approach is to calibrate a groundwater flow model such that the aquifer characteristics reproduce measured historical water levels throughout the basin given estimates of historical recharge and pumping. The latter approach produces estimates of aquifer characteristics averaged over spatial scales of thousands to tens of thousands of feet and time scales of months to decades. The estimates account for preferential flow through localized sand and gravel lenses in the basin fill materials and for delayed water-table responses to deep pumping. Also, model calibration provides estimates of vertical hydraulic conductivity across the layers of alluvial deposits, which is rarely measured by aquifer tests. The temporal and spatial scales represented by the model calibration approach are better for addressing most long-term groundwater management questions.

Bedford-Coldwater GSP
Groundwater Model Report 25 TODD GROUNDWATER

4.4.2. Zone Approach
Because of the limited data for aquifer properties for the Basin, a zoned distribution pattern was used that applied aquifer properties over subregional areas with similar geologic conditions. Although the units are heterogeneous, the approach was to get a representative average value for each aquifer property for limited number of zones around the basin. This was to avoid the patchwork quilt type of aquifer property distribution that does not show any relation to the underlying geologic conditions that define the aquifer property.

Figures 25 shows the distribution of aquifer characteristics after calibration of hydraulic conductivity and specific storage, respectively. The initial estimates of hydraulic conductivity and specific yield were from available local data, which incorporated major geologic features such as relatively permeable sediments in the upper parts of alluvial fans.

4.4.3. Hydraulic Conductivity
Hydraulic conductivity represents the ability of the water to flow through the aquifer, and is defined horizontally within a model layer to represent groundwater flow through the aquifer and vertically between adjacent model layers to represent groundwater exchange between aquifers.

The definition of the horizontal hydraulic conductivity is based on an assessment of lithologic description, available aquifer test data and model calibration. Since each model layer represents a thick interval composed of varying lithologies, the horizontal hydraulic conductivity represents an average value over the entire vertical thickness that includes the finer-grained layers in addition to any specific sand and gravel zone. For the Bedford-Coldwater Model, horizontal hydraulic conductivity is defined using regionalized blocks based on the geologic character of the unit and refined during calibration.

The hydraulic conductivity used in the Bedford-Coldwater Model varies within a reasonable value range for the aquifer characteristics for each aquifer to achieve the model calibration. The horizontal hydraulic conductivities used in the Bedford-Coldwater Model are listed in Table 3.

4.4.4. Vertical Conductance
In general, groundwater flow within an aquifer is dominantly horizontal whereas flow between adjacent aquifers is essentially vertical. The application of vertical hydraulic conductivity recognizes the inherent isotropy present in natural geologic formations. Vertical groundwater flow is equivalent to Ohm’s Law for serial electrical flow through different resistivity layers. Based on this analogy, vertical groundwater flow, similar to serial electrical flow, is limited by the lowest conductivity (or highest resistivity) layer encountered. Therefore, vertical groundwater flow is defined by the lowest-permeability, continuous layer that controls the exchange of groundwater between aquifer or model layers.

In MODFLOW, vertical groundwater flow between model layers is calculated using vertical conductance (VCONT) that is calculated as the conductance of two one-half cells in a series with continuous saturation between them (Harbaugh, 2005). This calculation is performed within MODFLOW and requires the input of a vertical hydraulic conductivity (Kz) for each layer. In general, Kz values were set to allow relatively free exchange between layers. The vertical hydraulic conductivity values used in the model to calculate the VCONT are summarized in Table 3.

Bedford-Coldwater GSP
Groundwater Model Report 26 TODD GROUNDWATER

4.4.5. Specific Yield and Specific Storage
Aquifer storage defines the ability of the aquifer to take in or release water. Under unconfined conditions, water released from or put into aquifer storage represents the physical draining of groundwater from interstitial pore space within the aquifer. Unconfined storage is defined by specific yield, which is typically consistent with the effective porosity of the aquifer. Under confined conditions, water released from or put into aquifer storage is derived from the compressibility of water as a result of changes in the aquifer pressure within the interstitial pore space.

MODFLOW 2005 requires the use of specific storage, which is in the units of feet-1. Reasonable ranges for the specific yield and specific storage were varied within a reasonable range during the model calibration and the values are listed in Table 3, respectively.

4.5. INITIAL CONDITION
The model also requires that groundwater levels be specified at the start of the simulation. They were estimated based on contouring of available water level data. As the initial heads may be dynamic and not representative of stable initial conditions, the first stress period representing pre-1990 conditions were run as steady-state to facilitate the calculation of a stable hydrologic system.

The transient model was used to develop the initial groundwater elevations that serve as the starting condition for the transient model. For this, groundwater pumping was applied to represent the longterm average pumping prior to 1990. The surface recharge component used to estimate groundwater recharge was set to a predevelopment condition to reduce the effect of urbanization. The results of the transient model provided a reasonable groundwater elevation data representing the late 1980’s to obtain an appropriate starting condition. This was an iterative process and the transient model used to develop the initial head was updated during the transient model calibration to incorporate significant changes in the model setup. Figure 26 provides the starting head for Layers 2, which provides a reasonable representation of the groundwater conditions for Layers 1 and 3.

Bedford-Coldwater GSP
Groundwater Model Report 27 TODD GROUNDWATER

5. HISTORICAL MODEL RESULTS
The Bedford-Coldwater Model was calibrated using the developed calibration criteria to reduce uncertainty by matching model results to observed data. An extensive calibration process was designed to better constrain the range of aquifer properties and boundary conditions for the model, thereby reducing uncertainty in the results.

5.1. CALIBRATION METHODOLOGY
For the Bedford-Coldwater Model, the simulation is setup using a 29-year base period that covers Water Year (WY) 1990 to WY2018. This aspect of the calibration is important to demonstrate that the model has the capability to simulate historical changes in groundwater elevations, and is therefore capable of forecasting future changes in groundwater elevations. This capability is necessary for the model to serve as a useful groundwater management tool.

5.1.1. Approach
The transient calibration is a process that compares the simulated groundwater levels from the model to observed groundwater level measurements. During calibration, boundary condition parameters and aquifer properties are varied within the reasonable range defined by the hydrogeological conceptual model. Different combinations are tested to determine the set of parameters and properties that produce an acceptable correlation simulated to measured groundwater elevations over time. Other data sets, such as key water budget components, surface water conditions, or hydrogeological conceptual model, may be used to further constrain the calibration.

There are multiple combinations of aquifer properties and boundary conditions that can be used to match a single set of groundwater elevation data. Calibrating to multiple data sets under differing stresses (i.e. recharge and discharge rates) reduces this “non-uniqueness”, thereby reducing the uncertainty. Performing a comprehensive calibration over a 29-year base period infers the calibration has been performed over wet, dry, and normal years with varying degrees of pumping. To that end, the Bedford-Coldwater Model was primarily calibrated using groundwater levels. The measures of calibration are primarily from a statistical analysis along with a visual assessment groundwater level trends from hydrographs. The groundwater elevation maps and water budget data considered during the model calibration are assessed in context with the model results, so are discussed in the next section.

5.1.2. Calibration Methodology
Joint calibration of the rainfall-runoff-recharge model, the surface water budget models and the groundwater flow model applied heuristic methods (i.e. trial-and-error adjustments) to selected variables, as informed by the timing and location of model residuals. In accordance with the principle of parsimony in modeling (DWR, 2016), calibration began with a small number of broad zones for hydraulic conductivity and storage. Zones were subdivided during calibration if a pattern of residuals at multiple wells warranted it. Although storage and hydraulic conductivity are not necessarily correlated, in practice they often are to some degree. Thus, for simplicity, similar zonation patterns were used for both variables.

In practice, most of the calibration effort focused on adjustments to horizontal and vertical hydraulic conductivity, the locations and conductances of faults, stream bed vertical hydraulic conductivity, and Bedford-Coldwater GSP
Groundwater Model Report 28 TODD GROUNDWATER
several tributary watershed parameters: root depths of natural vegetation, rainfall-runoff thresholds and slopes, and the leakage and recession rates for shallow groundwater. Variables that were not adjusted during calibration include land use, crop root depths, pumping locations, and groundwater pumping.

Model performance during the calibration process was evaluated primarily by visual inspection of superimposed measured and simulated water-level hydrographs. Adjustments to model inputs and parameters were made only if two or more wells in a given area exhibited similar patterns of discrepancies between measured and simulated water levels. The process of manually calibrating a groundwater model also produces considerable insight into the groundwater flow system and the factors that influence it. Water levels for some wells were easy to reproduce with the model, while others were more difficult.

5.1.3. Primary and Alternative Calibration
In this report, we provide two sets of calibration results. Primarily, this was done to provide two variations for simulating the quarry operations in the Coldwater MA. These two calibration versions include:
• Primary Calibration – the Primary Calibration is the version of the historical model that is carried forward as the final model calibration that is used as the based for the projected future scenarios.
• Alternative Calibration – the Alternative Calibration is presented to demonstrate that uncertainty regarding the quarry operations, primarily in the Coldwater MA, may indicate a data gap. The Alternative Scenario is presented for informational purposes to document this work for future model updates, but it is not used for the projected future scenarios.

Quarry outflows represents outflows associated with active or passive quarry operations to account for observed water conditions within the deeper quarry pits. In the Coldwater area, excavations occur within the large quarry pits following periods of high groundwater levels for the period from 1990 to 2010. Based on available information, no additional pumping to maintain quarry water levels was assumed to occur. However, during model calibration, it was necessary to assume that additional pumping or other groundwater removal occurred during these operational periods to maintain the observed groundwater levels.

For the Primary Calibration, quarry outflows were simulated using a combination of the EVT and Drain Packages (see Section 4.3.7). From 1990 to 2010, the quarry outflows were allowed to be higher assuming some limited additional pumping may have occurred. However, after 2010, no additional pumping to maintain quarry water levels has occurred and that is supported by the historical model calibration. The ET rate and drain conductance were varied during model calibration to simulate the average annual losses from the MWH (2004) report. However, the calibration results (see following discussion) did not fully capture the high and low observed groundwater near the Coldwater MA quarries.

For the Alternative Calibration, a different simulation method was applied at the quarry locations. The emphasis of the Alternative calibration was to apply a boundary condition that would more forcefully simulate the observed groundwater levels. For the Alternative Calibration, the quarry operations were simulated using the MODFLOW river package. The River Package can allow the quarry pit ponds to alternate from recharge to discharge based on monthly hydrologic conditions. We estimated the water surface based on a review of Google Earth satellite images of the quarries and other local reports.

Bedford-Coldwater GSP
Groundwater Model Report 29 TODD GROUNDWATER

5.2. STATISTICAL CALIBRATION
The calibration was evaluated using a statistical comparison of difference (or residual) between measured and simulated groundwater elevations. The calibration was done for the entire Subbasin. In addition, a breakdown of the calibration results for each of the management areas is also provided.

5.2.1. Primary Calibration Results
For the Basin, the calibration is based on observed groundwater elevations from 3,736 measurements in 27 wells over the 29-year base period from October 1989 through September 2018 (WY1990-2018). The locations of these wells are shown on Figures 27 and 28 for the Bedford MA and Coldwater MA, respectively.

Next, a more rigorous calibration was performed involving a statistical analysis to compare the difference or residual between measured and simulated groundwater elevations. An initial comparison is made with a scatter plot (Figure 29) that depicts this relationship of observed versus simulated groundwater elevations. As indicated on Figure 29, the scatter along the correlation line is minor in comparison to the range of the data. The correlation coefficient for the data on this graph is 0.905. The correlation coefficient ranges from 0 to 1 and is a measure of the closeness of fit of the data to a 1 to 1 correlation. A correlation of 1 is a perfect correlation. The correlation coefficient of 0.905 indicates a strong correlation between simulated and observed groundwater elevations.

A more detailed statistical analysis is provided that compares the difference, or residual, between measured and simulated groundwater elevations. Table 4 summarizes statistical measures used to assess the calibration. A brief summary of the statistical measures used to evaluate the calibration results shown on Table 4 is summarized below:
• The residual mean is computed by dividing the sum of the residuals by the number of residual data values. The closer this value is to zero, the better the calibration especially as related to the water balance and estimating the change in aquifer storage. The residual mean is 16.0 feet. • The absolute residual mean is the arithmetic average for the absolute value of the residual so it provides a measure of the overall error in the model. The absolute residual mean is 42.1 feet. • The residual standard deviation evaluates the scatter of the data. A lower standard deviation indicates a closer fit between the simulated and observed data. The standard deviation for the calibrated model is 31.5 feet.
• The Root Mean Square (RMS) Error is the square root of the arithmetic mean of the squares of the residuals is provides another measure of the overall error in the model. The RMS Error for the calibrated model is 45.0 feet.
• The scaled absolute residual the ratio of the absolute residual mean is divided by the range of observed groundwater elevations. This ratio helps to put the variation of the residuals into perspective with respect to the scale of the groundwater basin. This ratio for the BedfordColdwater Model is 0.077, which puts the statistical variability at less than 8 percent of the range. A ratio below 0.15 is generally considered a well calibrated (ESI 2011).

It should be noted that some degree of difference (or residual) between the observed and simulated groundwater elevations is expected. Residuals may be due in part to localized effects or data quality issues. For example, residuals can result from using groundwater elevations from pumping wells as calibration targets. MODFLOW calculates the groundwater elevation for the center of a model cell Bedford-Coldwater GSP
Groundwater Model Report 30 TODD GROUNDWATER
rather than at the well location itself. MODFLOW also does not consider the impact of well efficiency on groundwater elevations at pumping wells. In addition, the timing of the observed groundwater elevations does not exactly match the model stress periods. Since the several calibration locations being pumping wells, the statistical parameters are considered reasonable indicating that the model is well calibrated. Table 5 (following text) provides a summary statistics for each of the 59 wells used in the calibration process.

Table 4. Summary of Primary Calibration for the Bedford-Coldwater Model Calibration Measure Complete
GW Basin Bedford MA Coldwater MA
Units Feet Feet
Residual Mean 16.0 1.0 26.5
Residual Standard Deviation 42.1 11.2 97.0
Absolute Residual Mean 31.5 8.1 47.8
Root Mean Square (RMS)
Error

45.0 10.9 22.4
Scaled Absolute Residual
Mean

0.077 0.034 0.084
Number of Locations 27 13 14
Number of Observations 3,736 1,535 2,201
The statistical comparison is also consistent when evaluated by management area (MA). Table 4 includes the statistical calibration results for the Bedford-Coldwater Model by MA. The residual mean varies from 1.0 feet in the Bedford MA to 26.5 in the Coldwater MA. The standard deviation ranges from

11.2 feet in the Bedford MA to 97.0 feet in the Coldwater MA. The absolute residual mean ranges from

8.1 feet in the Bedford MA to 47.8 feet in the Coldwater MA. The scaled absolute residual mean ranges from 0.034 in the Bedford MA to 0.084 in the Coldwater MA.

The higher variability indicated in Coldwater MA is primarily attributed to the greater number of groundwater levels from active pumping that increases the variability of the observed data over the calibration period. Conversely, the Bedford MA has less variability because of less groundwater pumping and narrow range in groundwater levels over the calibration period. The statistical results are of high quality and indicate that each MA is well calibrated.

5.2.2. Alternative Calibration Results
For the Alternative Calibration, the boundary conditions were adjusted to simulate the observed groundwater levels more forcefully with no limitations on the effect on the water budget. For the Alternative Calibration, the quarry operations were simulated using the MODFLOW river package. The River Package can allow the quarry pit ponds to alternative from recharge to discharge based on monthly hydrologic conditions. We estimated the water surface based on a review of Google Earth satellite images of the quarries and other local reports.

A comparison of the statistical analysis for the Coldwater MA between the Primary and Alternative Calibration is provided in Table 6. A brief summary of the statistical measures used to evaluate the calibration results for the Coldwater MA are summarized on Tables 4 and 6 below:
• The residual mean for the Alternative Calibration is -4.3 feet compared to 26.5 feet for the Primary Calibration.

Bedford-Coldwater GSP
Groundwater Model Report 31 TODD GROUNDWATER
• The absolute residual mean for the Alternative Calibration is 87.2 feet compared to 97.0 feet for the Primary Calibration.
• The residual standard deviation for the Alternative Calibration is 29.7 feet compared to 47.8 feet for the Primary Calibration.
• The Root Mean Square (RMS) Error for the Alternative Calibration is 20.1 feet compared to

22.4 feet for the Primary Calibration 45.0 feet.
• The scaled absolute residual ratio for the Alternative Calibration is 0.055 feet compared to 0.084 for the Primary Calibration.

The water budget results were considered to be unrealistically high for quarry operations, so they are not provided and the Primary Calibration is the selected calibration results for the GSP. However, the Alternative Calibration indicates that a significantly improved model calibration but this is currently limited by potential uncertainty regarding the historical quarry operations. Therefore, the Alternative Calibration suggests that the quarry operations present a potentially significant data gap moving forward. Therefore, an improved understanding quarry operations may help to enhance future model calibration.

Table 6. Summary of Alternative Calibration for the Bedford-Coldwater Model Calibration Measure Complete GW
Basin Bedford MA Coldwater MA
Units Feet Feet
Residual Mean -1.6 2.2 -4.3
Residual Standard Deviation 30.9 11.4 87.2
Absolute Residual Mean 21.3 9.2 29.7
Root Mean Square (RMS) Error 30.9 11.3 20.1
Scaled Absolute Residual Mean 0.044 0.038 0.055
Number of Locations 27 13 14
Number of Observations 3,736 1,533 2,201

5.2.3. Comparison to Previous Model Calibration for Coldwater MA The primary performance measure is to improve upon the calibration from the previous models.

Previous groundwater models have been developed for the Coldwater MA; however, no previous groundwater model exist for the Bedford MA. In the MWH (2004) report, the model calibration results listed in the report was a general goal of a residual mean of less than 40-feet over the 1977 to 2010 simulation period. Both the Primary and Alternative Calibration both have residual means that are • The residual mean of 26.5 feet for the Primary Calibration (Table 4) for the 2021 GSP Model is an improvement of 34 percent compared to the 2004 MWH Model. • The residual mean of -4.3 feet for the Alternative Calibration (Table 6) for the 2021 GSP Model is an improvement of 89 percent compared to the 2004 MWH Model.

Overall, the results of the calibration showed significant improvement in the calibration over the 2004 MWH model. Although the data points used for both versions of the models are the same, the number of observations did vary. This indicates that the changes implemented for the Bedford-Coldwater Model were successful and resulted in improved model performance.

Bedford-Coldwater GSP
Groundwater Model Report 32 TODD GROUNDWATER

5.3. GROUNDWATER LEVEL TRENDS
Hydrographs provide a detailed time history of groundwater elevations for specific wells. This time history data includes the impact of varying climatic and pumping stresses on the groundwater basin.

Comparing hydrographs of model results versus observed data provides a measure of how well the model handles these changing conditions through time. Groundwater elevation data for 26 hydrographs from different parts of the basin are included on Figures 30 through 36 for the hydrograph evaluation.

Locations of these well used for the hydrographs are shown on Figures 27 and 28.

For calibration purposes, the hydrographs were inspected to evaluate how well the model results matched the overall magnitude and trend of the observed groundwater elevation data over time. For the transient model, it was considered more important to honor the overall trend of the data. A hydrograph was considered a good match if the model simulated the trend, but the groundwater elevations were offset. The following is a discussion of the overall groundwater trends, comparison of simulated to measured data, and other hydrogeological inferences made from the historical simulation results shown on the Figures 30 through 36 hydrographs.

5.3.1. Bedford MA Hydrographs
Hydrographs from twelve wells located in different areas within the Bedford MA are shown on Figures 30 through 32. Well locations are shown in Figure 27. To facilitate a comparison of the relative groundwater trends observed in these wells, a consistent vertical scale of 250 feet is used on Figures 30 through 32.

The North Temescal Wash Area is located along Temescal Wash in the northern portion of the Bedford MA. Figures 30 and 31 show hydrographs for 8 wells located within this area. Groundwater levels in this area are generally characterized as having relatively stable trends over time. Also, depth to groundwater in many parts of this area are relatively shallow ranging from 5 to 50 feet. Data from Corona #4 prior to 1992 show that groundwater levels were lower during this period. Groundwater levels were relatively stable. From 2012 through 2018 groundwater levels become more variable reflecting changes in groundwater pumping and climatic conditions.

Hydrographs for four monitoring wells are located in the mid-Temescal Wash (Figure 32). Locations of these wells are shown on Figure 27. Three of these wells are located area near the TVWD WRF (TVWD#01A, TVWD#04, and LLWD_#01-Old). These wells show very stable water levels over the period of record. In this area, groundwater levels are stabilized by the level of Temescal Wash and the presence of two flooded gravel mine pits in the mined area north of TVWD WRF.

The New Sump well, also shown on Figure 32, a is located further upstream from the TVWD WRF near the confluence with Dawson Creek which flows in from the upland areas to the east. Groundwater levels show more variability due to pumping at this location and the narrow constricted configuration of the aquifer at this location.

For all twelve wells, the comparison of simulated to measured groundwater levels shows a close correlation which is consistent with the statistical data presented on Tables 4 and 5.

5.3.2. Coldwater MA Hydrographs
Hydrographs from thirteen wells located in different areas within the Coldwater MA are shown on Figures 33 through 36. Well locations are shown in Figure 27. To facilitate a comparison of the relative Bedford-Coldwater GSP
Groundwater Model Report 33 TODD GROUNDWATER
groundwater trends observed in these wells, a consistent vertical scale of 600 feet is used on Figures 33 through 36 to capture the full range and variability of groundwater levels in the Coldwater MA.

Figures 33 shows hydrographs for four wells located within in the Coldwater Creek area of the Coldwater MA. These wells are located near the Chandler gravel mining operations which is the northernmost gravel pit (Figure 23). It is in the Coldwater MA that the difference between the Primary and Alternative Calibration are most apparent. The measured groundwater levels for the four hydrographs on Figure 33 shows a consistent pattern that is summarized below:
• From 1989 through 1992, groundwater levels are relatively low, with elevations ranging between 800 to 900 feet above mean sea level (msl). This is considered to represent a period of active mining operations and deepening of the pits to near or below the water table. • During the period from 1993 through 1999, groundwater levels rapidly rise in 1993 due to flood events where flood flows are either directed into or breached berms to flood the mining areas.

The result is a major recharge event during high rainfall events in 1993, 1995, 1997 and 1998. As a result, groundwater levels rise 150 to 200 feet to reach elevations between 1,000 and 1,050 feet elevation msl.
• From 2000 through 2004, groundwater levels decline between 100 to 200 feet with elevations ranging between 750 to 850 feet above mean sea level (msl). This is a period of active mining in the large, deep mining areas.
• In 2005, another large flooding event occurred that results in major recharge event with groundwater rising about 100 feet to reach elevations between 850 and 900 feet elevation msl. • From 2006 through 2010, groundwater levels decline between 100 to 150 feet with elevations ranging between 750 to 800 feet above mean sea level (msl). This is a period of active mining in the large, deep mining areas.
• In 2010 and 2011, another large flooding event occurred that results in major recharge event with groundwater rising about 100 feet to reach elevations between 850 and 900 feet elevation msl.
• From 2011 through 2016, groundwater levels decline between 100 to 150 feet with elevations ranging between 750 to 800 feet above mean sea level (msl). This is a period of active mining in the large, deep mining areas and mine reclamation.
• From 2016 to 2018, groundwater levels rise about 50 feet to an elevation of about 800 feet msl.

This represents a period where mining operations are occurring well above the water table.

Deeper areas of the mine have undergone reclamation and are no longer active.

During model calibration, this pattern of groundwater elevation changes was not fully obtained by using reported pumping volumes, streamflow from the rainfall-runoff model, and local ET rates. The general form was achieved, but not the full extent, especially the high groundwater levels in the 1990s. The Alternative Calibration applied a boundary condition to more forcefully drive the simulation to simulate the measured groundwater levels; however, this resulted in significantly higher groundwater extraction or loss rates to achieve the decline from the high groundwater level periods in the 1990s, 2005 and 2011 to the corresponding low groundwater levels in 2004, 2010, and 2016. Because of the water budget issue, the model calibration used the Primary Calibration; however, the Alternative Calibration indicates a potentially significant data gap in understanding the effects of mining operations on groundwater levels.

Bedford-Coldwater GSP
Groundwater Model Report 34 TODD GROUNDWATER
Figures 34 and 35 show hydrographs for six wells located within in the Mayhew area of the Coldwater MA which is located south of the wells shown in Figure 33. A similar pattern of groundwater level change is shown in these areas; however, the mining operations in these areas are more typically above the groundwater table such that the difference between the Primary and Alternative Calibration is less significant than for the wells in Figure 33. These wells show relatively strong agreement between measured and simulated groundwater levels over the simulation period.

Figure 36 shows hydrographs for four wells located north of the Coldwater MA and north of the wells shown in Figure 33. The pattern in the change in groundwater levels shows a similar pattern but the magnitude of the changes is much less. These wells are located further away from the mining areas which suggests much of these changes are related to mining operations. The Primary and Alternative Calibrations show a general match to the pattern and magnitude of the groundwater level changes over the simulation period, but show some offset in simulating the groundwater elevation.

5.4. EVALUATION OF GROUNDWATER FLOW
The Bedford-Coldwater Model simulates monthly groundwater elevations for 348 months from October 1989 through September 2018. In general, the overall groundwater flow directions remain generally consistent over this time with some variations observed near the major groundwater pumping centers.

To evaluate the range of groundwater elevations, we have selected a few key time periods. These include:
• Figure 37 - End of Historical Simulation Period – September 2018 • Figure 38 - Period of consistently high groundwater levels – March 1995 • Figure 39 - Period of consistently low groundwater levels – October 2010 The high and low conditions represent a combination of climatic conditions and groundwater pumping demands. Groundwater maps for Layers 1 for each of the above time periods is presented. In general, groundwater levels in Layers 1, 2 and 3 are generally consistent. For the purposes of evaluating groundwater flow directions, we have selected Layer 1 as representative of these three layers.

Figure 37 shows the groundwater level contours and flow directions for Layer 1 at the end of the historical simulation period representing September 2018 conditions. On each of these maps, large blue arrows to better illustrate the groundwater flow directions. The groundwater contour represents a line of equal groundwater elevation, or equipotential. Groundwater flow occurs at right angles to the contour lines with the direction flow from the higher to lower groundwater elevation. In general, groundwater flow in the Bedford MA is generally towards or along Temescal Wash. Along the Glen Ivy Fault groundwater flow directions are generally parallel to the fault in the southern area, but flow is away from the fault in the northern areas of the Bedford MA.

In the Coldwater MA, groundwater flow is generally from the marginal areas towards the primary pumping wells located within the area of the large gravel mining operations (Figure 37). The thinner aquifer along the basin margins has limited capacity to store the recharge that occurs along the basin margins from runoff, stream recharge and bedrock inflows. This, along with the higher elevations, creates higher groundwater elevations along the margins that drives groundwater flow into the center of the basin.

The tightly-spaced contours along the Glen Ivy Fault (Figure 37) that separates the Bedford and Coldwater MA represent the flow restriction formed by the faults that limits inflows into the deep basin and maintains higher, relatively stable groundwater levels upgradient of the faults. Within the deep basin, the groundwater levels are several hundred feet lower than on the areas upgradient faults.

Bedford-Coldwater GSP
Groundwater Model Report 35 TODD GROUNDWATER
Figures 38 show the groundwater elevations during March 1995. During this period, widespread high groundwater levels were observed reflecting a period of high precipitation and below average groundwater pumping rates occurring in the basin. Even in this case, the general groundwater flow directions remain generally consistent with September 2018 (Figure 37). The main differences are increased groundwater levels in the Coldwater MA and northern Bedford MA reflect increased recharge from creek reaching this area along with lower pumping. Steeper groundwater levels are observed along the basin margins reflecting the higher recharge rates due to the high precipitation levels.

Figure 39 shows the groundwater elevations during October 2010. During this period, widespread low groundwater levels were observed reflecting several preceding dry years. In general the groundwater flow directions remain generally consistent with September 2018 (Figures 37). The main differences are lower groundwater levels in the Coldwater MA due to groundwater pumping with limited recharge. In the Bedford MA, groundwater levels are also generally lower across the area due to lower recharge. .

The groundwater flow is consistent with the hydrogeological conceptual model. These maps are included to demonstrate that the model provides reasonable simulation of groundwater elevation and flow direction even during the more extreme climatic periods during the base period. This further demonstrates that the model is well calibrated and can accurately simulate wet and dry weather periods.

5.5. MODEL-BASED HYDROLOGIC BUDGET
GSP regulations (§354.18(c)(2)(B)) indicate a need to identify an average hydrologic study period that cover as least 10 years that includes a range of hydrologic conditions (e.g. wet, normal, dry and critically dry) for purposes of the groundwater analyses in the basin-wide water budgets. In order to select a consistent study period, the Bedford-Coldwater GSA is using a 29-year base period covering Water Years (WY) 1990 through 2018. Water years used for the Bedford-Coldwater Model run from October through to the following September to capture the cause and effect relationship on groundwater levels of wintertime rain and subsequent summertime groundwater pumping. Additional analysis of the historical water budget is provided in Section 5 (“Water Budget”) of the GSP.

The model-derived groundwater budget for the entire Basin is presented in Table 7. Over the entire simulation period, groundwater inflows average about 9,300 AFY. Surface recharge from precipitation and return flows accounts for about 24 percent of the total recharge and average about 2,200 acre-feet per year (AFY). Groundwater-surface water interactions represent about 50 percent of the total recharge and average about 4,600 AFY. Mountain front recharge represents inflows from bedrock units into the basin from the surrounding watersheds. This accounts for about 15 percent of the total recharge and average about 1,350 AFY. Recharge from wastewater recharge ponds accounts for about 7 percent or 650 AFY. Groundwater inflow from the adjacent Temescal and Elsinore Valley Basins account about 4 percent of the total recharge and average about 370 AFY. Net recharge from quarry operations accounts for about 1 percent of the total recharge and averages about 100 AFY.

Outflows from the entire Basin, Table 7, average about 11,323 AFY. Groundwater pumping is the primary groundwater outflow accounting for about 63 percent of the outflow and averages about 7,100 AFY over the entire historical period. Quarry operations in both the Bedford MA and Coldwater MA account for about 21 percent of the outflow and averages about 2,400 AFY. Evapotranspiration (ET) accounts for about 7 percent of the outflow and averages about 780 AFY. Groundwater outflow from the adjacent Temescal and Elsinore Valley Basins account about 2 percent of the total recharge and average about 230 AFY.

Bedford-Coldwater GSP
Groundwater Model Report 36 TODD GROUNDWATER
Similar groundwater budget tables are presented for the each of the management areas defined within the Bedford-Coldwater GSA. These include:
• Table 8 for the Bedford MA
• Table 9 for the Coldwater MA
The difference between the model-derived inflows and outflows represents the change in groundwater in storage over the simulation period. Table 10 summarizes the change in groundwater in storage for the entire Basin and for each of the individual subareas and are graphically illustrated on Figure 40. The overall change in storage over the simulation period for the entire Basin average a decline of about 2,000 AFY for a cumulative decline over the simulation period of about 59,000 AFY. OF this, the majority of the decline is experienced in the Coldwater MA where the majority of the groundwater pumping occurs. Most of the decline in groundwater in storage occurs prior 2002 when pumping rates were higher and quarry operations appear to be more active with respect to groundwater resources. Since 2008, EVWMD and the City of Corona have had an operating agreement for pumping within the Coldwater MA. As a results, the average change in groundwater in storage from 2005 through 2015 is an increase of 22 AFY for a cumulative increase of 240 acre-feet (Table 10).

Bedford-Coldwater GSP
Groundwater Model Report 37 TODD GROUNDWATER

6. SIMULATION OF FUTURE CONDITIONS
GSP regulations §354.18(c)(3) require simulation of several future scenarios to determine their effects on water balances, yield and sustainability indicators. The following scenarios to simulate future conditions include:
• Baseline Scenario - This represents a continuation of existing land and water use patterns, imported water availability, and climate.
• Growth Plus Climate Change Scenario - This scenario implements anticipated changes in land use and associated water use, such as urban expansion, and anticipated effects of future climate change on local hydrology (rainfall recharge and stream percolation) and on the availability of imported water supplies.

The historical period used for model calibration consisted of only 29 years (water years 1990-2018). The Sustainable Groundwater Management Act requires that future simulations cover a 50-year period. To obtain 50 years of hydrology, rainfall, reference ET and streamflow were assumed to repeat the 1993- 2017 sequence twice. Rainfall during that period equaled 99 percent of the long-term average. Surface and subsurface inflows from tributary watersheds simulated using the rainfall-runoff-recharge model were also replicated to obtain 50 years of data. The initial conditions for the future baseline simulation equaled the ending water levels of the calibration simulation, or September 2018. Thus, the future simulation period nominally covers water years 2019 to 2068.

The future Baseline Scenario and Growth Plus Climate Change Scenario serve as a reference conditions against which to compare alternative management scenarios. Additional data and assumptions used in the future baseline simulation are described in Section 5 of the GSP (“Water Budget”). Inputs and results of other scenarios related to specific management actions recommended in the GSP are also described in Section 8 (“Management Actions”).

6.1. BASELINE SCENARIO
The simulation is of a 50-year period, as required by SGMA regulations. For the simulations of future conditions, the hydrology is assumed to repeat the 1993 to 2017 calibration period twice to obtain 50 years of data. Specific assumptions and data included in the future baseline scenario are outlined below.

6.1.1. Baseline Assumptions
Municipal, commercial, and industrial (M&I) and private pumping were assumed to remain at existing levels. Initial estimates were obtained by calculating average pumping for each calendar month during 2010 through 2018 and applying those averages in every year of the future simulation. This approach omits additions to and withdrawals from Coldwater MA storage accounts by the three municipal agencies with wells in that MA. Municipal use of imported water was also assumed to remain at existing levels. From the standpoint of the groundwater budget, total municipal water use was used only to estimate pipe leaks. Use of imported water by the Temescal Valley Water District (TVWD) was obtained from that agency’s 2015 Urban Water Management Plan (RMC/Woodard Curran 2017), and imported water use in the parts of the City of Corona (Corona) and Elsinore Valley Municipal Water District (EVMWD) service areas within the Basin were assumed to be the same on a per-acre basis for developed areas. Updated pumping volumes were input into the model with the MODFLOW well package.

Bedford-Coldwater GSP
Groundwater Model Report 38 TODD GROUNDWATER
Land use and water use were assumed to remain at their current patterns and levels throughout the 50-year period. Land use remains the same as actual, existing conditions. In the model these are represented by 2014 land use mapped by remote sensing methods and obtained from DWR, adjusted for subsequent urbanization identified in Google Earth imagery. These data were used in the rainfallrunoff-recharge model for estimated hydrologic parameters for MODFLOW model input.

Rainfall and reference evapotranspiration (ET0) used historical monthly data for the 1993-2017 hydrologic period used in the model. The surface recharge was input using the MODFLOW recharge package and ET from groundwater rates are input using the MODFLOW EVT package.

Small stream inflows and bedrock inflow simulated for 1993 to 2017 of the calibration simulation were repeated twice to obtain 50 years of data Stream flows are entered in the MODFLOW model using the SFR2 package and the bedrock inflow is input using GHB package. Wastewater percolation and recycled water discharges to TVWD WRF recharge ponds and Temescal Wash were assumed to continue as under the current levels.

Initial water levels are simulated water levels for September 2018 from the historical calibration simulation. That year represents relatively recent, non-drought conditions. These simulated water levels are internally consistent throughout the model flow domain and reasonably matched measured water levels at wells with available data.

6.1.2. Baseline Water Budget Results
GSP regulations (§354.18(c)(2)(B)) require a 50-year simulation period of average hydrologic conditions (e.g. wet, normal, dry and critically dry) for purposes of the analyses in the projected-future basin-wide water budgets. The Future Baseline Scenario generally assumes a continuous of current groundwater operations and historical hydrology over the 50-year simulation period. Additional analysis of the historical water budget is provided in Section 5 (“Water Budget”) of the GSP.

The model-derived groundwater budget for the entire Basin is presented in Table 11. Over the entire simulation period, groundwater inflows average about 10,100 AFY. Surface recharge from precipitation and return flows accounts for about 23 percent of the total recharge and average about 2,300 acre-feet per year (AFY). Groundwater-surface water interactions represent about 44 percent of the total recharge and average about 4,500 AFY. Groundwater-surface water interactions primarily account for recharge from streams, including wastewater and recycled water discharge to streams. Mountain front recharge represents inflows from bedrock units into the basin from the surrounding watersheds. This accounts for about 12 percent of the total recharge and average about 1,250 AFY. Recharge from wastewater recharge ponds accounts for about 19 percent or 1,850 AFY. Net recharge from quarry operations accounts for about 2 percent of the total recharge and averages about 160 AFY.

Groundwater inflow from the adjacent Temescal and Elsinore Valley Basins account about 1 percent of the total recharge and average about 80 AFY.

Outflows from the entire Basin, Table 11, average about 9,200 AFY. Groundwater pumping is the primary groundwater outflow accounting for about 47 percent of the outflow and averages about 4,400 AFY over the entire historical period. Quarry operations in both Bedford and Coldwater MA account for about 26 percent of the outflow and averages about 2,400 AFY. Groundwater-surface water interactions represent about 11 percent of the total outflows and average about 1,000 AFY. ET accounts for about 10 percent of the outflow and averages about 900 AFY. Groundwater outflow from the adjacent Temescal and Elsinore Valley Basins account about 6 percent of the total recharge and average about 530 AFY.

Bedford-Coldwater GSP
Groundwater Model Report 39 TODD GROUNDWATER
Similar groundwater budget tables are presented for the each of the management areas defined within the Bedford-Coldwater GSA. These include:
• Table 12 for the Bedford MA
• Table 13 for the Coldwater MA
The difference between the model-derived inflows and outflows represents the change in groundwater in storage over the simulation period. Table 14 summarizes the change in groundwater in storage for the entire Basin and for each of the individual subareas and are graphically illustrated on Figure 51. The overall change in storage over the simulation period for the entire Basin average is an increase of about 850 AFY for a cumulative increase over the 50-year simulation period of about 43,000 AFY. Of this, the majority of the increase is experienced in the Coldwater MA where the most significant changes to groundwater pumping occurs. The rate of the change in groundwater in storage increases from 140 AFY during the implementation period of the GSP (2018-2041). During the sustainability period of the GSP (2042-2068) the rate of the change in groundwater in storage increases from 830 AFY (Table 14).

6.1.3. Baseline Groundwater Flow Evaluation
A contour map of simulated groundwater elevations from the Baseline Scenario at the end of the simulation period (September 2068) is presented in Figure 42. In the Bedford MA, groundwater conditions remain generally consistent with September 2018 (Figures 37) with hydraulic gradients generally directed towards or along Temescal Wash. Only minor variations in groundwater levels are observed in the Bedford MA primarily related to shifts in groundwater pumping. This is consistent with the historical data which shows the Bedford MA with minimal change in groundwater in storage over time.

In the Coldwater MA, groundwater levels are generally about 100 feet or more higher in the center of the Coldwater MA. This is primarily due to the use of lower pumping rates in the Baseline that are consistent with present day pumping practices. The City of Corona and Elsinore Valley Municipal Water District established a production agreement in 2008 to ensure the sustainable use of groundwater in the Coldwater area (Corona and EVMWD, 2008). Prior to 2008, groundwater pumping in the Coldwater MA was much higher. Therefore, the Baseline Scenario results indicated that continued application of the 2008 agreement are anticipated to result in significant increases in groundwater levels over the 50-year simulation period.

6.2. GROWTH AND CLIMATE CHANGE SCENARIO
The growth plus climate change scenario incorporated anticipated effects of climate change, urban development and associated changes in water and wastewater management. The input parameters for the growth plus climate change scenario were input using the same MODFLOW packages as listed in the Baseline Scenario setup. Specific assumptions and data included in the growth plus climate change scenario are outlined below.

6.2.1. Growth and Climate Change Assumptions
For the growth plus climate change scenario, average annual groundwater pumping in the Coldwater MA was assumed to equal average historical pumping during 2010 through 2017, with an increase proportional to the estimated amount of irrigation return flow from future increased use of imported water. In the Bedford MA average annual groundwater pumping was assumed to be equal to 2020 Bedford-Coldwater GSP
Groundwater Model Report 40 TODD GROUNDWATER
production volumes. Municipal pumping in Coldwater was distributed among wells in proportion to their averages during 2010 to 2017 and in Bedford it was distributed as recorded in 2020. All remaining municipal water use was assumed to be obtained from imported water. Projected water use for irrigated turf in the rainfall-runoff-recharge model indicated that the combined effect of the warmer and drier climate will be to increase annual irrigation demand by about 10 percent.

A map of the zones and their land uses projected for 2068 is shown in Figure 42. The categories are listed in Table 1 (Section 3.2) along with their total acreages in the groundwater basin management areas and tributary watersheds. Projected land use in 2068 was developed on the basis of population projections, land use designations in the Temescal Canyon Area Plan (Riverside County 2018), assumed urban infill, and topography. A comparison of land use acreage by land use category and management area for 1990, 2018, and 2068 was developed. Conversion of grassland to residential land use was the dominant change in both management areas and also occurred in tributary watershed areas.

Rainfall and reference evapotranspiration (ETo) were adjusted to 2070 conditions using monthly multipliers developed by DWR based on climate modeling studies. The climate in 2070 is expected to be drier and warmer than it presently is. The multipliers were applied to historical monthly data for the 1993-2017 hydrologic period used in the model. DWR prepared a unique set of multipliers for each 4-km2 cell of a grid covering the entire state. Fourteen grid cells overlie the Basin and its tributary watershed areas. For each recharge analysis polygon in the rainfall-runoff-recharge model, multipliers from the nearest grid cell were used.

Bedrock inflow and surface inflow from tributary streams along the perimeter of the Basin were resimulated using the rainfall-runoff-recharge model to reflect the effects of urban development in some of the tributary watersheds and of climate change. Urbanization also increased surface runoff within the Basin, which was routed to small streams and Temescal Wash.

Wastewater generation was assumed to double by 2068, in proportion to the increase in total urban water use. Wastewater disposal was assumed to change, however. In recent years more of the outflow from the TVWD WRF has been percolated in ponds than has been recycled for irrigation. This proportion was assumed to reverse, such that all outflow would be recycled for irrigation during April through November and all would be percolated in ponds during November through March. The small discharge from Corona WRF-3 to Temescal Wash at the northern end of the Basin was assumed to be eliminated, consistent with the City of Corona’s plans to decommission that WRF.

Water pipe leak rates in the EVMWD and City of Corona service areas were assumed to decrease to 5 percent of delivered water from the rates reported in the 2015 Urban Water Management Plans (7.0 percent and 6.6 percent, respectively). The leak rate in the TVWD service area was assumed to continue at the low rate reported in 2015 (two percent).

In the growth plus climate change scenario, gravel mining operations were assumed to have ended and the mine areas to have been converted to stormwater control facilities with groundwater recharge capacity during high runoff periods.

6.2.2. Growth and Climate Change Scenario Water Budget Results GSP regulations (§354.18(c)(2)(B)) require a 50-year simulation period of average hydrologic conditions (e.g. wet, normal, dry and critically dry) for purposes of the analyses in the projected-future basin-wide water budgets. The Growth with Climate Change Scenario includes planned changes in the groundwater operations in the basin along with projected climate change based on data provided by DWR. Additional analysis of the historical water budget is provided in Section 5 (“Water Budget”) of the GSP.

Bedford-Coldwater GSP
Groundwater Model Report 41 TODD GROUNDWATER
The model-derived groundwater budget for the entire Basin is presented in Table 15. Over the entire simulation period, groundwater inflows average about 11,400 AFY. Surface recharge from precipitation and return flows accounts for about 26 percent of the total recharge and average about 2,900 acre-feet per year (AFY). Groundwater-surface water interactions represent about 39 percent of the total recharge and average about 4,500 AFY. Net recharge from quarry operations accounts for about 4 percent of the total recharge and averages about 470 AFY. Groundwater-surface water interactions primarily account for recharge from streams, including wastewater and recycled water discharge to streams. Mountain front recharge represents inflows from bedrock units into the basin from the surrounding watersheds. This accounts for about 11 percent of the total recharge and average about 1,250 AFY. Recharge from wastewater recharge ponds accounts for about 19 percent or 2,200 AFY.

Groundwater inflow from the adjacent Temescal and Elsinore Valley Basins account about 1 percent of the total recharge and average about 80 AFY.

Outflows from the entire Basin, Table 15, average about 10,600 AFY. Groundwater pumping is the primary groundwater outflow accounting for about 48 percent of the outflow and averages about 5,000 AFY over the entire historical period. Quarry operations in both Bedford and Coldwater MA account for about 23 percent of the outflow and averages about 2,500 AFY. Groundwater-surface water interactions represent about 13 percent of the total outflows and average about 1,400 AFY. ET accounts for about 11 percent of the outflow and averages about 1,200 AFY. Groundwater outflow from the adjacent Temescal and Elsinore Valley Basins account about 4 percent of the total recharge and average about 470 AFY.

Similar groundwater budget tables are presented for the each of the management areas defined within the Bedford-Coldwater GSA. These include:
• Table 16 for the Bedford MA
• Table 17 for the Coldwater MA
The difference between the model-derived inflows and outflows represents the change in groundwater in storage over the simulation period. Table 18 summarizes the change in groundwater in storage for the entire Subbasin and for each of the individual subareas and are graphically illustrated on Figure 52.

The overall change in storage over the simulation period for the entire Basin average is an increase of about 850 AFY for a cumulative increase over the 50-year simulation period of about 42,600 AFY. Of this, the majority of the increase is experienced in the Coldwater MA where the most significant changes to groundwater pumping occurs. The rate of the change in groundwater in storage increases from 150 AFY during the implementation period of the GSP (2018-2041). During the sustainability period of the GSP (2042-2068) the rate of the change in groundwater in storage increases from 800 AFY (Table 18).

6.2.3. Future Growth and Climate Change Groundwater Map A contour map of simulated groundwater elevations from the Growth and Climate Change Scenario at the end of the simulation period (September 2068) is presented in Figure 45. In the Bedford MA, groundwater conditions remain generally consistent with September 2018 (Figures 37) with hydraulic gradients generally directed towards or along Temescal Wash. Only minor variations in groundwater levels are observed in the Bedford MA primarily related to shifts in groundwater pumping. Furthermore, the groundwater conditions remain generally consistent with September 2068 Baseline Scenario results (Figures 42). The Growth and Climate Change Scenario adds an additional 1,200 AFY in groundwater pumping; however, a similar increase in groundwater recharge, primarily from urban return flows, generally balances these results.

Bedford-Coldwater GSP
Groundwater Model Report 42 TODD GROUNDWATER
As with the Baseline Scenario, groundwater levels for the Growth and Climate Change Scenario are generally about 100 feet in the center of the Coldwater MA due to the use of lower pumping rates compared to the historical pumping. The City of Corona and Elsinore Valley Municipal Water District established a production agreement in 2008 to ensure the sustainable use of groundwater in the Coldwater area (Corona and EVMWD, 2008). Prior to 2008, groundwater pumping in the Coldwater MA was much higher. Therefore, the Growth and Climate Change Scenario results indicated that continued application of the 2008 agreement are anticipated to result in significant increases in groundwater levels over the 50-year simulation period.

Bedford-Coldwater GSP
Groundwater Model Report 43 TODD GROUNDWATER

7. SGMA REQUIREMENTS
As noted in the SGMA Modeling Best Management Practices (BMP) guidelines (DWR, 2016), the description of the model application should include detailed information on the model conceptualization, assumptions, data inputs, boundary conditions, calibration, sensitivity and uncertainty analysis, and there applicable modeling elements such as model limitations. A DWR requirement for using model results in future water budget reporting for Annual Reports is to report the model accuracy. The following information addresses these reporting requirements.

7.1. MODEL DATA GAPS
When evaluating model results, it is important to consider the strengths and limitations of the numerical model. The horizontal and vertical resolution used to construct the model dictates the range of scales that the model can evaluate. The Bedford-Coldwater Model is designed as a regional or basin-wide model to evaluate long-term, regional trends and the overall groundwater inflow and outflow to the basin. Within that scale, conditions are averaged. However, this model may not contain the site-specific details necessary to evaluate some localized conditions due to geologic complexity or unique localized effects. For these areas, a more localized model may be required if such a detailed analysis is necessary.

The regional model can provide a broader regional context to support the development of these localized models.

The groundwater flow model is an appropriate tool for evaluating groundwater conditions at the basin and subarea scale over periods of months to decades. Given its reasonable calibration under a wide range of historical hydrologic and water management conditions, it should produce reliable results under a similar range of future conditions. However, some aspects of the model and some types of applications may be less reliable. Limitations in model accuracy and in types of applications include the following:
• Understanding of water use and groundwater interaction with deep mining operations that intersect the groundwater present a data gap that presented challenges during the calibration.

These issues were most prominent in the Coldwater MA, but also influenced some localized areas around the TVWD WRF in the Bedford MA. The Alternative Calibration indicates that calibration is limited by uncertainty regarding the historical quarry operations. A better understanding of quarry operations could provide an improved understanding to help enhance future model calibration.
• As with any regional model, the model cannot simulate details of water levels and flow at spatial scales smaller than one model cell. It cannot, for example, simulate drawdown within a pumping well. It can only simulate the average effect of that pumping on the average water level of the cell in which the well is located.
• The monthly stress periods of the model preclude simulation of brief hydrologic stresses. For example, the model cannot simulate the effects of daily pumping cycles on water levels, or the amount of recharge associated with peak stream flow events. • Surface and subsurface inflows from tributary watersheds around the perimeter of the basin remain uncertain. The new rainfall-runoff-recharge model simulates watershed hydrology explicitly but flows from the watersheds to the groundwater basin are small compared to rainfall and ET. Accurate data for those variables within the watershed areas are not available, and a small error in rainfall or ET can result in a large error in simulated watershed outflow.

Bedford-Coldwater GSP
Groundwater Model Report 44 TODD GROUNDWATER
• Model calibration is better in some parts of the basin than others. For any future model application that focuses on a particular subarea, it would be prudent to evaluate the quality of model calibration for that area before conducting simulations of alternative conditions.

7.2. MODEL ACCURACY
A numerical model mathematically describes the conceptual model by solving the mass balance and motion equations that govern groundwater flow and chemical transport (Bear and Verruijt 1987). To solve these equations, an iterative method is used to solve the matrix equations. For these iterative techniques, the procedure is repeated until the convergence criteria are met. The convergence criteria may be groundwater elevation change, mass balance difference, or both. Convergence defines whether the model is mathematically stable and capable of producing reliable results.

For this model, the Newton (NWT) Solver Package was used (Niswonger et al, 2011). The convergence criteria for NWT included both a maximum change in groundwater elevation and a maximum mass balance differential for a cell. For this model, the convergence parameter for groundwater elevation was set at 0.001 feet and 50 cubic feet per day for mass balance differential. Convergence is evaluated at the grid cell level. If a single cell does not meet the requirement, then the solution procedure is repeated.

The model was able to successfully converge using the set convergence parameters.

The primary method to check whether the model is numerically stable is to evaluate the differential in mass balance. Iterative techniques provide an approximate solution for the model; therefore, there is always a mass balance differential. This differential should be small, and typically a differential of less than 1.00 percent is considered as a good solution. The mass balance differential for Bedford-Coldwater Model is 0.03%. These values further indicate that numerical model that is accurately simulating the flow of groundwater in the Basin.

The model calibration and comparison of the hydrologic budget results demonstrate that the model is consistent with the conceptual model to produce these results. The calibration correlation coefficient of

0.905 demonstrates a strong comparison between measured and simulated groundwater elevations.

Other statistical calibration parameters show that the scaled ratio of the parameter to the range of observed groundwater levels is about 10 percent. Based on these parameters, the accuracy of the Bedford-Coldwater Model is considered to range between 10 to 15 percent.

7.3. LIMITATIONS TO CALIBRATION
All inputs to a model are estimates that are subject to errors or uncertainty, but some are better known than others. Also, some have relatively pronounced effects on simulation results. For example, the amount of water pumped by municipal wells is metered and is considered highly accurate compared to most model inputs. Accordingly, the amount of municipal pumping was not adjusted during calibration.

Data gaps with the water use with quarry operations and the groundwater interactions with the deep mining operation pits presented a challenge for calibration. Variables were selected for adjustment during calibration based on their relative uncertainty, the sensitivity of results to that variable, and whether the variable might logically be connected to an observed pattern of residuals based on hydrologic processes.

The measured water levels that serve as the basis for calibration are themselves subject to uncertainty stemming from wellhead elevation errors, effects of recent pumping at the measured well, and wells that for unknown reasons have water levels inconsistent with water levels at nearby wells. Almost all of Bedford-Coldwater GSP
Groundwater Model Report 45 TODD GROUNDWATER
the wells used to monitor water levels are active water supply wells. If a well was pumping shortly before the water level is measured, the water level will be much lower (by feet to tens of feet) than if the well had been idle for a day or more. In some hydrographs, pumping-affected water levels stand out as obvious anomalies. A number of those points were removed from the calibration data set. In other cases, water levels fluctuate over a wide range seasonally and between measurements, and pumping effects could not be systematically identified and eliminated.

Bedford-Coldwater GSP
Groundwater Model Report 46 TODD GROUNDWATER

8. REFERENCES CITED
Bear, J. and A. Verruijt, 1987, Modeling Groundwater Flow and Pollution, D. Reidel Publishing Company, Boston, 414 p.

Bicknell, B.R., Imhoff, J.C., Kittle, J.L., Jr., Donigian, A.S., Jr., and Johanson, R.C., 1997, Hydrological Simulation Program--Fortran, User's manual for version 11: U.S. Environmental Protection Agency, National Exposure Research Laboratory, Athens, Ga., EPA/600/R-97/080, 755 .

Blaney, H.F., P.R. Nixon, G.P. Lawless and E.J. Wiedmann. October 1963. ,Utilization of the waters of the Santa Ynez River basin for agriculture in southern Santa Barbara County, California. U.S. Department of Agriculture, Agricultural Research Service., Riverside, CA.

California Department of Water Resources (DWR). ), 2003. , Bulletin 118.

California Department of Water Resources (DWR). ), 2016. Management Practices for the Sustainable Management of Groundwater, Modeling BMP, Sacramento, CA: Technical Memorandum.

California Department of Water Resources (DWR). ),April 1975. , Vegetative Water Use Inin California, 1974. Bulletin 113-3. Sacramento, CA.,
California Geological Survey (CGS), 2002, Wagner, D.L., H.G. Greene, G.J. Saucedo, and C.I. Primdore, Geologic Map of Monterey 30’ x 60’ Quadrangle and Adjacent Areas, California: A Digital Database, Publication No. CD 2002-04, 2002.

Clark, W.O. 1924. Ground water in Santa Clara Valley, California. Water-Supply Paper 519. U.S.

Geological Survey, Washington, D.C.

Corona and Elsinore Valley Municipal Water District (EVMWD), 2008, Agreement Concerning Water Production from Coldwater, December.

Environmental Simulations, Inc. 2011. Guide to Using Groundwater Vistas, Version 6. Reinholds, PA.

Fetter, C.W. 1994. Applied hydrogeology. 3rd edition. Prentice Hall. Upper Saddle River, NJ.

Harbaugh, A.W. 2005. MODFLOW 2005, the U.S. Geological Survey modular ground-water model—the ground-water flow process. Chapter 16, Book 6--modeling techniques, Techniques and Methods 6-A16.

U.S. Geological Survey, Reston, VA.

Irrigation Training and Research Institute (ITRC). January 2003. California crop and soil evapotranspiration for water balances and irrigation scheduling/design. ITRC Report 03-001. San Luis Obispo, CA. Prepared for CALFED/DWR/USBR, Sacramento, CA.

Kilburn, C. August 31, 1972. Ground-Water Hydrology Of The Hollister And San Juan Valleys, San Benito County, California, 1913-68. Open-File Report 73-144. U.S. Geological Survey, Menlo Park, CA.

Lewis, D.C. and R.H. Burgy, 1964, The Relationship between oak tree roots and groundwater in fractured rock as determined by tritium tracing, Journal of Geophysical Research, Vol. 69 No. 12, 15 June 1964, p 2579-2588.

Bedford-Coldwater GSP
Groundwater Model Report 47 TODD GROUNDWATER
Lubczynski, M.W., 2011, Groundwater Evapotranspiration – Underestimated Role of Tree Transpiration and Bare Soil Evaporation in Groundwater Balances of Dry Lands, in Climate Change and its Effects on Water Resources, NATO Science for Peace and Security Series C: Environmental Security Volume 3, 2011, pp 183-190.

Markstrom, S.L., Regan, R.S., Hay, L.E., Viger, R.J., Webb, R.M.T., Payn, R.A., and LaFontaine, J.H., 2015, PRMS-IV, the precipitation-runoff modeling system, version 4: U.S. Geological Survey Techniques and Methods, book 6, chap. B7, 158 p., http://dx.doi.org/10.3133/tm6B7.

Meinzer, O.E., 1927, Plants as indicators of ground water: USGS Water-Supply Paper 577.

Micko, Jeff. December 2014. Report On Simulation Model For The Multi-Purpose Operation Of Pacheco Reservoir In The Pacheco Creek Sub-Watershed Of The Pajaro River. Micko Consultants. Prepared for the California Department of Fish and Wildlife, Sacramento, CA.

MWH, 2004, Coldwater Basin Recharge Feasibility Study, a technical report submitted to the Elsinore Valley Municipal Water District, March 2004, 177 p.

Natural Resources Conservation Service. 2015. SSURGO soil survey on-line map database available at http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx . Downloaded 27 March 2015.

Niswonger, R.G., S. Panday, and M. Ibaraki, 2011, MODFLOW-NWT, A Newton Formulation for MODFLOW-2005, U.S. Geological Survey Techniques and Methods G-A37, 44p.

Pritchard, T. 2009. Irrigation management of wine grapes with a limited water supply. University of California Cooperative Extension. Davis, CA.

Rantz, S.E. 1969. Mean annual precipitation in the California region. Basic-Data Compilation 1020-01.

U.S. Geological Survey, Menlo Park, CA.

Rawls, W.J., L.R. Ahuja, D.L. Brakensiek and A. Shirmohammadi. 1993. , Infiltration and Soil Water Movement. Chapter 5 in D.R. Maidment, ed. Handbook of Hydrology, McGraw-Hill, Inc. New York, NY.

RMC and Woodard & Curran, 2017, 2015 Urban Water Management Plan, Temescal Valley Water District, December, available at:
https://www.temescalvwd.com/pdf/TVWD_UWMP_Public%20Draft%20w%20Appendices.pdf Robinson, T.W., 1958, Phreatophytes: USGS Water-Supply Paper 1428.

Snyder, R.L., M. Orang, K. Bali and S. Eching, Revised 2007, Basic Irrigation Scheduling (BIS), Computer software manual, Department of Land, Air and Water Resources, University of California. Davis, CA.

Todd Engineers and AKM Consulting Engineers (Todd and AKM), 2008, AB3030 Groundwater Management Plan, prepared for City of Corona, June.

United Nations Food and Agriculture Organization (UNFAP). 2006. Crop evapotranspiration. Technical Report No. 56. Rome, Italy.

Van Mullen, J.A., D.E. Woodward, R.H. Hawkins, and A.T. Hjelmfelt, Jr., No date (but after 2001), Runoff curve number method: beyond the handbook, Curve-Number Working Group, Natural Resources Bedford-Coldwater GSP
Groundwater Model Report 48 TODD GROUNDWATER
Viessman, W., Jr., J.W. Knapp, G.L. Lewis, and T.E. Harbaugh., 1977, Introduction to Hydrology, 2nd edition, Harper & Row, Publishers. New York, NY.

Wildermuth Environmental, Inc. (WEI), 2015b, Draft Feasibility Investigation (Phase I) to Develop a Potable Water-Supply from the Bedford Basin, prepared for the City of Corona, Elsinore Valley Water District, and Lee Lake Water District, August.

Williams, L.E. 2001. Irrigation of wine grapes in California. Practical Winery & Vineyard Journal.

November/December 2001.

Wu, J.E., K. McClay, P. Whitehouse, and T. Dooley, 2012, 25 - 4D analogue modelling of transtensional pull-apart basins, in Regional Geology and Tectonics: Principles of Geologic Analysis, Editor(s): D.G.

Roberts, A.W. Bally, Elsevier, 2012, Pages 700-730, https://doi.org/10.1016/B978-0-444-53042-4.00025- X.

Bedford-Coldwater GSP
Groundwater Model Report TODD GROUNDWATER
TABLES
Table 2 - Annual Groundwater Pumping Volumes by Well (acre-feet per year) Well_Name HA 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Corona #04 Bedford 291 253 305 269 33 332 173 103 215 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 Flager #02 Bedford 620 940 1,001 279 54 418 289 606 606 202 656 560 420 643 578 523 16 147 495 517 19 0 0 0 0 0 0 0 0 0 0 Flager #03 Bedford 679 614 392 432 117 337 61 111 287 1 1 141 533 705 4 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Flagler #02A Bedford 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 289 420 444 36 0 0 37 207 Flagler #03A Bedford 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 475 458 699 16 0 0 42 202 Foster Bedford 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 220 275 169 185 New Sump Bedford 501 479 570 379 57 128 185 328 429 45 336 575 439 435 239 342 33 2 241 358 295 388 57 12 198 200 13 288 680 414 278 Non Potable #01 Bedford 0 0 0 0 0 0 0 0 0 0 0 0 0 0 245 0 0 0 0 0 0 258 28 1 1 1 450 368 185 243 380 Non Potable #02 Bedford 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 177 131 151 253 268 327 0 0 1 1 1 0 0 0 0 0 Old Ranch Bedford 0 1 19 18 248 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Old Sand Plant Bedford 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Rose #02 Bedford 84 33 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Rose #03 Bedford 56 16 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Rose #04 Bedford 153 52 7 168 238 206 8 18 0 0 31 30 4 12 6 1 4 3 3 3 1 1 1 1 1 1 440 295 476 385 410 Rose #09 Bedford 236 130 475 523 887 0 0 262 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 TVWD 1 Bedford 172 51 166 183 230 34 207 0 0 0 31 30 4 29 6 1 4 3 3 3 1 1 1 1 1 1 442 163 445 354 425 TVWD TP1 Bedford 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 324 205 TVWD TP2 Bedford 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 174 96 Coldwater City Park Coldwater 110 160 680 1,020 1,300 260 1,300 19 16 16 17 1 1 15 17 17 18 17 0 0 0 0 0 0 0 0 0 0 0 0 0 Corona #01 Coldwater 1,278 1,062 1,001 1,174 1,663 1,285 1,685 1,680 1,629 1,614 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Corona #02 Coldwater 157 0 0 394 1,152 1,059 1,191 1,256 1,016 1,067 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Corona #03 Coldwater 1,155 1,024 1,107 1,192 1,368 1,072 1,391 1,297 1,349 1,110 770 506 4 1 237 380 978 1,316 1,083 999 897 952 491 559 83 392 881 460 3 0 0 Corona #20 Coldwater 0 0 0 0 0 0 0 0 0 0 1,489 0 0 0 0 0 338 801 430 361 186 238 186 57 212 196 19 0 0 0 0 Corona #21 Coldwater 0 0 0 0 0 0 0 0 0 2,461 4,364 3,493 2,528 2,579 2,345 2,401 1,506 1,609 2,004 1,955 2,018 1,942 761 662 1,432 1,658 1,254 1,508 764 178 0 Div Box Well Coldwater 0 0 0 0 388 419 563 468 125 125 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Mayhew #01 Coldwater 921 662 678 212 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Mayhew #02 Coldwater 0 0 235 853 1,108 356 727 436 649 737 587 462 318 348 219 596 493 377 432 383 413 457 436 467 747 400 286 575 174 748 Noble #1 Maitri Rd Coldwater 147 135 112 90 75 69 65 81 95 101 170 37 139 172 207 348 16 23 0 0 507 477 497 547 558 547 535 556 586 565 522 SantaAna #1 UpperCyn Coldwater 81 44 80 88 86 100 111 113 5 83 110 12 45 0 0 0 0 0 0 0 0 0 27 102 41 26 44 34 66 45 45 SantaAna #2 LowerCyn Coldwater 9 9 11 12 18 18 9 14 3 30 22 0 0 0 0 0 0 0 0 0 0 0 0 1 1 2 0 2 8 9 8 Smith #2 Coldwater 32 32 32 32 32 32 38 40 41 37 41 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Smith Lower #1 Coldwater 35 35 35 35 35 35 33 35 30 27 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Smith Upper #2 Coldwater 5 5 5 5 5 5 3 3 2 3 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Station #26 Coldwater 164 165 116 89 14 3 30 109 77 20 13 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Station #71 Coldwater 632 476 306 500 858 577 881 930 1,226 690 318 551 378 399 241 185 30 139 216 131 120 100 0 111 238 388 24 97 92 0 175 Station #72 Coldwater 344 302 303 332 369 345 322 288 200 126 337 456 422 353 276 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Warm Sprg Coldwater 73 73 73 73 73 62 72 73 73 72 67 72 75 72 71 73 72 71 72 72 68 0 0 0 0 0 0 54 57 56 57 Well #1 Coldwater 83 89 71 57 37 26 31 40 47 53 62 8 3 2 2 11 555 620 608 569 0 0 0 0 0 0 0 0 0 0 0 Bedford Bedford 2,792 2,570 2,935 2,251 1,864 1,455 923 1,428 1,537 248 1,055 1,336 1,400 1,824 1,078 1,046 188 306 995 1,149 643 648 87 780 1,080 1,347 1,397 1,334 2,061 2,142 2,389 Coldwater Coldwater 5,226 4,273 4,610 5,540 8,326 6,475 8,081 7,173 6,370 8,284 8,550 5,723 4,057 3,911 3,744 3,634 4,110 5,089 4,791 4,520 4,179 4,122 2,419 2,475 3,032 3,955 3,157 2,998 2,152 1,027 1,555 Total 8,018 6,843 7,545 7,791 10,190 7,930 9,004 8,601 7,907 8,532 9,605 7,059 5,457 5,735 4,822 4,680 4,298 5,395 5,786 5,669 4,822 4,770 2,506 3,255 4,112 5,302 4,554 4,332 4,213 3,169 3,944 Subtotals
Table 3 - Aquifer Properties for MODFLOW Zones by Model Layer Zone Name MA Model Layer 1 Model Layer 2 Model Layer 3
1 Mayhew Area Coldwater 5 2 1
2 Mid Wash Bedford 100 10 1
3 Bedford Canyon Bedford 5 2 1
4 Midlands South Bedford 2 2 1
5 North Wash Bedford 100 10 1
6 South Wash Bedford 40 5 1
7 Coldwater Creek Coldwater 10 2 1
8 North Area Coldwater 2.5 2 1
9 Midlands North Bedford 2 1 1
Zone Name MA Model Layer 1 Model Layer 2 Model Layer 3
1 Mayhew Area Coldwater 1 0.2 0.5
2 Mid Wash Bedford 5 5 0.5
3 Bedford Canyon Bedford 2.5 0.2 0.1
4 Midlands South Bedford 0.4 0.2 0.1
5 North Wash Bedford 5 5 5.0E-01
6 South Wash Bedford 4 0.5 5.0E-01
7 Coldwater Creek Coldwater 1 0.2 0.5
8 North Area Coldwater 0.25 0.2 5.0E-01
9 Midlands North Bedford 0.4 0.1 1.0E-01
Zone Name MA Model Layer 1 Model Layer 2 Model Layer 3
1 Mayhew Area Coldwater 1.0E-04 2.0E-05 1.0E-05
2 Mid Wash Bedford 2.0E-04 1.0E-04 1.0E-05
3 Bedford Canyon Bedford 1.0E-04 2.0E-05 1.0E-05
4 Midlands South Bedford 1.0E-04 2.0E-05 1.0E-05
5 North Wash Bedford 5.0E-04 1.0E-04 1.0E-05
6 South Wash Bedford 1.0E-03 1.0E-04 1.0E-05
7 Coldwater Creek Coldwater 1.0E-03 2.0E-05 1.0E-05
8 North Area Coldwater 2.0E-03 1.0E-05 1.0E-05
9 Midlands North Bedford 1.0E-04 1.0E-05 1.0E-05
Zone Name MA Model Layer 1 Model Layer 2 Model Layer 3
1 Mayhew Area Coldwater 0.05 0.03 0.02
2 Mid Wash Bedford 0.15 0.1 0.02
3 Bedford Canyon Bedford 0.05 0.03 0.02
4 Midlands South Bedford 0.05 0.03 0.02
5 North Wash Bedford 0.15 0.1 0.02
6 South Wash Bedford 0.11 0.1 0.02
7 Coldwater Creek Coldwater 0.08 0.05 0.02
8 North Area Coldwater 0.05 0.02 0.02
9 Midlands North Bedford 0.05 0.01 0.02
Horizontal Hydraulic Conductivity (feet/day)
Vertical Hydraulic Conductivity (feet/day)
Specific Storage (1/feet)
Specific Yield (percentage)
Table 5 - Statistical Calibration by Well
Well ID
Model
Layer Count
Residual
Mean (feet)
Absolute
Residual
Mean (feet)
Standard
Deviation
(feet)
Management
Area
B_Well 1 106 47.7 47.7 12.8 Coldwater
Corona#01 1 152 31.8 43.2 38.6 Coldwater
Corona#02 1 108 48.7 59.0 42.6 Coldwater
Corona#03 1 378 15.8 35.5 40.4 Coldwater
Corona#04 1 183 -5.9 12.7 16.6 Bedford
Corona#20 1 181 -35.7 44.3 45.3 Coldwater
Corona#21 1 99 18.8 26.6 28.0 Coldwater
Div_Box_Well 1 71 46.8 46.8 21.4 Coldwater
Flager#02 1 276 5.9 6.4 4.6 Bedford
Flager#03 1 145 8.5 10.7 8.2 Bedford
Flagler#02A 1 133 0.4 4.9 7.6 Bedford
Flagler#03A 1 196 -3.3 5.2 7.4 Bedford
Flagler#04 1 90 5.3 6.9 5.8 Bedford
LLWD_#01-Old 1 11 -2.6 5.5 5.6 Bedford
Mayhew#01 1 261 36.4 52.8 52.7 Coldwater
Mayhew#02 1 15 43.0 64.4 65.1 Coldwater
New_Sump 1 352 0.9 9.8 13.4 Bedford
Non-Potable#01 1 64 -2.1 6.3 7.5 Bedford
Non-Potable#02 1 62 -3.8 7.3 10.1 Bedford
OLD_SUMP 1 1 3.6 3.6 NA Bedford
Station#22 1 58 58.0 58.7 38.2 Coldwater
Station#26 1 154 92.7 93.0 28.6 Coldwater
Station#71 1 309 4.9 40.2 50.5 Coldwater
Station#72 1 214 46.6 55.0 44.3 Coldwater
Trilogy 1 95 -7.3 32.8 35.1 Coldwater
TVWD#01A 1 11 -1.1 4.5 5.2 Bedford
TVWD#04 1 11 -3.0 5.0 4.8 Bedford
Basin Average 3736 16.02 31.6 42.49
Bedford Average 1535 0.21 6.83 8.05
Coldwater Average 2201 32.02 50.00 38.84
Table 7 - Bedford/Coldwater GW Basin Water Balance (in acre-feet per year) - Historical

INFLOWS OUTFLOWS
Surface
Recharge GW-SW
Mountain
Front
Recharge
Net Quarry
Ops
WRF Perc
Ponds
Boundary
Inflow Total Inflow Wells
Net Quarry
Ops GW-SW ET
Boundary
Outflow Total Outflow
1990 1,027 1,194 1,656 74 0 1,173 5,125 10,621 5,276 1,086 446 57 17,486 -12,361 -12,361 1991 1,954 6,303 1,660 7 0 1,218 11,142 10,130 2,014 747 445 59 13,395 -2,253 -14,614 1992 1,576 4,486 1,654 18 0 776 8,510 9,579 1,012 520 342 46 11,498 -2,988 -17,602 1993 7,001 19,899 1,641 418 0 206 29,167 11,724 1,214 1,588 1,090 370 15,986 13,181 -4,421 1994 961 1,366 1,645 314 0 399 4,684 11,391 1,006 1,011 537 117 14,062 -9,378 -13,799 1995 3,167 9,420 1,973 121 20 245 14,946 10,957 1,297 1,123 686 105 14,169 777 -13,022 1996 939 562 2,012 111 40 384 4,049 11,610 1,252 582 428 48 13,921 -9,871 -22,893 1997 1,007 345 1,721 11 62 685 3,831 10,893 1,112 234 267 33 12,539 -8,707 -31,601 1998 4,730 13,989 1,467 36 107 253 20,582 10,377 1,471 838 674 287 13,647 6,935 -24,666 1999 864 342 1,355 1 210 242 3,014 11,517 1,558 413 369 117 13,974 -10,960 -35,626 2000 1,154 527 1,047 14 309 415 3,466 9,543 2,383 117 501 33 12,577 -9,111 -44,737 2001 1,975 5,127 989 85 373 497 9,047 7,351 2,713 194 721 30 11,009 -1,962 -46,699 2002 734 73 1,161 56 473 928 3,425 6,803 2,751 94 740 24 10,412 -6,987 -53,686 2003 2,286 5,187 957 29 691 645 9,795 5,714 2,425 154 872 41 9,205 590 -53,096 2004 1,047 316 731 37 891 562 3,582 5,313 5,314 83 807 30 11,547 -7,965 -61,061 2005 9,460 23,787 1,390 1 1,029 124 35,791 5,075 2,336 2,387 1,654 631 12,083 23,708 -37,353 2006 1,872 3,870 1,855 38 854 87 8,577 5,978 1,989 2,174 977 783 11,901 -3,324 -40,676 2007 600 1,045 1,805 0 801 143 4,393 6,168 1,972 1,114 1,183 184 10,622 -6,229 -46,906 2008 582 695 1,680 0 525 313 3,795 5,829 3,525 666 813 44 10,877 -7,082 -53,988 2009 1,642 2,582 1,588 72 291 148 6,323 5,157 4,159 639 868 200 11,023 -4,700 -58,688 2010 3,801 8,513 1,214 14 285 80 13,906 4,919 3,743 953 1,226 541 11,382 2,524 -56,165 2011 4,804 10,308 1,241 30 0 75 16,459 3,162 1,875 1,584 1,256 869 8,746 7,713 -48,452 2012 1,086 1,174 1,452 18 487 94 4,310 3,124 1,689 1,187 759 355 7,114 -2,804 -51,256 2013 848 931 1,460 22 1,575 165 5,002 3,982 2,455 831 625 74 7,966 -2,964 -54,220 2014 1,108 792 1,429 25 1,646 399 5,399 5,090 2,438 568 564 49 8,708 -3,309 -57,529 2015 1,370 757 1,094 178 1,462 192 5,053 4,560 2,241 450 816 278 8,345 -3,292 -60,821 2016 1,083 565 463 252 386 92 2,841 4,244 1,232 257 306 324 6,362 -3,521 -64,342 2017 3,793 8,905 506 404 3,438 80 17,126 4,046 3,736 662 1,088 599 10,131 6,995 -57,348 2018 876 931 659 353 2,862 72 5,753 2,812 3,062 433 916 460 7,682 -1,929 -59,276 Average Water Budget over Simulation Period (1990-2018) Average 2,184 4,620 1,362 94 649 369 9,279 7,161 2,388 782 758 234 11,323 -2,044 Total 63,346 133,989 39,506 2,740 18,818 10,696 269,094 207,669 69,249 22,689 21,977 6,787 328,370 -59,276 Average Water Budget over Early Historical period (1993-2002) Average 2,253 5,165 1,501 117 159 426 9,621 10,217 1,676 619 601 116 13,230 -3,608 Total 22,533 51,651 15,011 1,167 1,594 4,255 96,212 102,166 16,758 6,194 6,014 1,164 132,296 -36,084 Average Water Budget over Late Historical period (2005-2015) Average 2,470 4,950 1,473 36 814 166 9,910 4,822 2,584 1,141 977 364 9,888 22 Total 27,172 54,452 16,208 399 8,956 1,821 109,007 53,044 28,421 12,553 10,742 4,007 108,768 240 Average Water Budget over Long Historical period (1993-2015) Average 2,306 4,852 1,431 71 527 317 9,504 7,228 2,301 825 802 228 11,383 -1,879 Total 53,037 111,605 32,908 1,632 12,132 7,283 218,597 166,237 52,918 18,984 18,435 5,242 261,816 -43,220 Average Water Budget over Current period (2008-2018)
Average 1,908 3,287 1,162 124 1,178 156 7,815 4,266 2,741 748 840 345 8,940 -1,125 Total 20,992 36,152 12,786 1,368 12,957 1,711 85,966 46,925 30,154 8,230 9,236 3,792 98,337 -12,371 Cumulative
Storage Change
Simulation
Year
Annual Storage
Change
Table 8 - Bedford MA Water Balance (in acre-feet per year) - Historical

INFLOWS OUTFLOWS
Surface
Recharge GW-SW
Quarry
Recharge
Mountain
Front
Recharge
WRF Perc
Ponds
Boundary
Inflow Total Inflow Wells GW-SW
Quarry
Outflow ET
Boundary
Outflow Total Outflow
1990 693 863 74 980 0 1,493 4,103 4,309 731 973 394 57 6,464 -2,361 -2,361 1991 1,270 2,248 7 981 0 1,514 6,020 4,056 559 1,153 369 59 6,196 -176 -2,537 1992 1,000 1,344 18 979 0 1,054 4,395 3,216 409 1,012 306 46 4,988 -593 -3,130 1993 4,800 3,920 418 977 0 423 10,538 3,230 1,495 1,214 768 370 7,076 3,462 332 1994 644 1,042 314 978 0 637 3,614 2,939 950 1,006 531 117 5,544 -1,930 -1,598 1995 2,085 2,422 121 1,185 20 427 6,260 2,349 1,080 1,297 609 105 5,441 819 -779 1996 654 494 111 1,194 40 563 3,057 2,554 563 1,252 427 48 4,845 -1,787 -2,566 1997 733 206 11 1,046 62 849 2,907 2,607 233 1,112 267 33 4,252 -1,345 -3,911 1998 3,219 3,159 36 897 107 354 7,772 1,462 832 1,471 545 287 4,597 3,174 -736 1999 647 341 1 833 210 342 2,375 1,861 413 1,558 369 117 4,318 -1,944 -2,680 2000 785 146 14 629 309 499 2,381 2,086 117 1,373 195 33 3,804 -1,423 -4,103 2001 1,274 1,731 85 592 373 556 4,611 2,040 193 1,108 294 30 3,664 947 -3,155 2002 475 72 56 693 473 977 2,746 2,212 94 1,145 268 24 3,743 -998 -4,153 2003 1,401 1,655 29 547 691 654 4,978 1,641 152 1,447 341 41 3,622 1,356 -2,796 2004 707 153 37 393 891 562 2,743 1,440 83 1,490 311 20 3,344 -601 -3,398 2005 6,337 4,947 1 848 1,029 124 13,287 902 2,377 2,279 1,037 553 7,149 6,138 2,740 2006 1,232 2,135 38 1,119 854 87 5,466 954 2,170 1,982 773 743 6,622 -1,157 1,584 2007 411 1,031 0 1,080 801 143 3,466 1,167 1,114 1,972 497 166 4,917 -1,451 133 2008 397 682 0 1,019 525 313 2,936 1,136 666 1,542 350 20 3,714 -778 -646 2009 1,023 1,205 72 969 291 148 3,707 795 637 1,290 418 150 3,291 416 -230 2010 2,511 2,888 14 706 285 80 6,483 669 949 1,654 626 457 4,355 2,128 1,898 2011 3,209 3,069 30 765 0 75 7,148 235 1,580 1,583 919 762 5,080 2,069 3,967 2012 768 1,172 18 894 487 94 3,434 632 1,187 1,689 759 270 4,537 -1,103 2,864 2013 604 931 22 897 1,575 165 4,194 1,032 831 2,455 625 -11 4,932 -738 2,126 2014 762 664 25 894 1,646 399 4,390 1,308 568 2,438 564 -46 4,831 -440 1,686 2015 954 577 178 686 1,462 192 4,049 1,202 450 2,241 429 171 4,493 -444 1,242 2016 744 403 252 297 386 92 2,174 1,191 257 1,232 292 207 3,178 -1,005 237 2017 2,521 2,847 404 341 3,438 80 9,631 1,625 660 3,736 585 463 7,069 2,562 2,800 2018 584 727 353 382 2,862 72 4,980 1,444 433 3,062 359 357 5,655 -675 2,125 Average Water Budget over Simulation Period (1990-2018) Average 1,464 1,485 94 821 649 447 4,960 1,803 751 1,647 491 195 4,887 73 Total 42,446 43,072 2,740 23,800 18,818 12,970 143,845 52,295 21,784 47,766 14,227 5,649 141,721 2,125 Average Water Budget over Early Historical period (1993-2002) Average 1,532 1,353 117 902 159 563 4,626 2,334 597 1,254 427 116 4,728 -102 Total 15,317 13,532 1,167 9,022 1,594 5,627 46,261 23,341 5,970 12,537 4,272 1,164 47,284 -1,023 Average Water Budget over Late Historical period (2005-2015) Average 1,655 1,755 36 898 814 166 5,324 912 1,139 1,920 636 294 4,902 422 Total 18,208 19,300 399 9,877 8,956 1,821 58,560 10,033 12,529 21,124 6,999 3,235 53,920 4,640 Average Water Budget over Long Historical period (1993-2015) Average 1,549 1,506 71 863 527 377 4,893 1,585 815 1,591 518 194 4,703 190 Total 35,633 34,641 1,632 19,840 12,132 8,664 112,542 36,455 18,735 36,599 11,922 4,459 108,170 4,372 Average Water Budget over Current period (2008-2018)
Average 1,280 1,379 124 714 1,178 156 4,830 1,024 747 2,084 539 255 4,649 181 Total 14,077 15,164 1,368 7,849 12,957 1,711 53,127 11,269 8,219 22,920 5,926 2,800 51,135 1,992 Cumulative
Storage Change
Simulation
Year
Annual Storage
Change
Table 9 - Coldwater MA Water Balance (in acre-feet per year) - Historical

INFLOWS OUTFLOWS
Surface
Recharge GW-SW
Mountain
Front
Recharge
Net Quarry
Ops
Boundary
Inflow Total Inflow Wells
Net Quarry
Ops GW-SW ET
Boundary
Outflow Total Outflow
1990 334 331 676 0 0 1,341 6,312 4,303 355 52 320 11,342 -10,000 -10,000 1991 684 4,055 678 0 0 5,418 6,074 861 188 76 296 7,495 -2,077 -12,077 1992 576 3,141 675 0 0 4,393 6,363 0 111 37 277 6,787 -2,395 -14,472 1993 2,201 15,979 665 0 0 18,845 8,493 0 93 323 217 9,126 9,719 -4,753 1994 317 324 667 0 0 1,308 8,451 0 61 6 238 8,756 -7,448 -12,201 1995 1,082 6,998 788 0 0 8,868 8,608 0 43 77 182 8,909 -42 -12,243 1996 285 68 818 0 0 1,171 9,056 0 19 2 179 9,255 -8,084 -20,327 1997 274 139 675 0 0 1,088 8,285 0 1 1 164 8,451 -7,363 -27,690 1998 1,511 10,831 570 0 0 12,912 8,915 0 5 129 101 9,151 3,761 -23,929 1999 217 1 522 0 0 740 9,656 0 0 0 100 9,756 -9,017 -32,946 2000 369 381 419 0 0 1,169 7,457 1,010 0 306 84 8,857 -7,688 -40,634 2001 702 3,396 397 0 0 4,494 5,312 1,605 2 427 59 7,404 -2,909 -43,544 2002 259 1 468 0 0 728 4,591 1,606 0 472 49 6,718 -5,990 -49,533 2003 884 3,532 410 0 0 4,826 4,073 977 2 531 9 5,592 -766 -50,300 2004 340 163 338 0 10 850 3,873 3,824 0 496 0 8,193 -7,344 -57,643 2005 3,122 18,840 542 0 77 22,582 4,173 57 10 617 0 4,857 17,724 -39,919 2006 641 1,735 736 0 40 3,152 5,024 7 4 204 0 5,238 -2,087 -42,005 2007 189 14 725 0 18 945 5,001 0 0 685 0 5,687 -4,741 -46,747 2008 185 13 661 0 24 883 4,693 1,983 0 463 0 7,139 -6,256 -53,002 2009 619 1,377 619 0 51 2,667 4,361 2,869 2 450 0 7,681 -5,015 -58,017 2010 1,290 5,625 508 0 83 7,506 4,250 2,089 4 601 0 6,943 562 -57,455 2011 1,595 7,239 476 0 106 9,416 2,927 292 4 337 0 3,560 5,856 -51,598 2012 317 1 558 0 85 961 2,492 0 0 0 0 2,492 -1,531 -53,129 2013 244 1 562 0 85 892 2,950 0 0 0 0 2,950 -2,058 -55,187 2014 346 127 536 0 95 1,104 3,783 0 0 0 0 3,783 -2,679 -57,866 2015 416 180 408 0 107 1,111 3,358 0 0 387 0 3,745 -2,633 -60,499 2016 339 162 166 0 117 784 3,053 0 0 14 0 3,067 -2,282 -62,782 2017 1,272 6,058 165 0 136 7,631 2,421 0 2 503 0 2,926 4,705 -58,077 2018 292 205 277 0 123 896 1,368 0 0 557 0 1,924 -1,028 -59,105 Average Water Budget over Simulation Period (1990-2018) Average 721 3,135 542 0 40 4,437 5,358 741 31 267 78 6,475 -2,038 Total 20,901 90,917 15,706 0 1,158 128,682 155,373 21,483 905 7,750 2,275 187,786 -59,105 Average Water Budget over Early Historical period (1993-2002) Average 722 3,812 599 0 0 5,132 7,882 422 22 174 137 8,638 -3,506 Total 7,216 38,118 5,989 0 0 51,323 78,824 4,221 224 1,742 1,372 86,384 -35,061 Average Water Budget over Late Historical period (2005-2015) Average 815 3,196 576 0 70 4,656 3,910 663 2 340 0 4,916 -260 Total 8,964 35,152 6,331 0 772 51,219 43,011 7,297 24 3,743 0 54,075 -2,856 Average Water Budget over Long Historical period (1993-2015) Average 757 3,346 568 0 34 4,705 5,643 710 11 283 60 6,706 -2,001 Total 17,404 76,965 13,068 0 782 108,218 129,782 16,319 250 6,513 1,381 154,245 -46,027 Average Water Budget over Current period (2008-2018)
Average 629 1,908 449 0 92 3,077 3,241 658 1 301 0 4,201 -1,123 Total 6,915 20,988 4,937 0 1,012 33,852 35,655 7,233 11 3,310 0 46,210 -12,358 Cumulative
Storage Change
Simulation
Year
Annual Storage
Change
Table 10 - Change in Groundwater in Storage (in acre-feet per year) - Historical Coldwater
Hydrologic Area
Bedford Hydrologic
Area
1990 -10,000 -2,361 -12,361 -12,361
1991 -2,077 -176 -2,253 -14,614
1992 -2,395 -593 -2,988 -17,602
1993 9,719 3,462 13,181 -4,421
1994 -7,448 -1,930 -9,378 -13,799
1995 -42 819 777 -13,022
1996 -8,084 -1,787 -9,871 -22,893
1997 -7,363 -1,345 -8,707 -31,601
1998 3,761 3,174 6,935 -24,666
1999 -9,017 -1,944 -10,960 -35,626
2000 -7,688 -1,423 -9,111 -44,737
2001 -2,909 947 -1,962 -46,699
2002 -5,990 -998 -6,987 -53,686
2003 -766 1,356 590 -53,096
2004 -7,344 -622 -7,965 -61,062
2005 17,724 5,984 23,708 -37,354
2006 -2,087 -1,237 -3,324 -40,677
2007 -4,741 -1,488 -6,229 -46,906
2008 -6,256 -826 -7,082 -53,989
2009 -5,015 314 -4,700 -58,689
2010 562 1,961 2,524 -56,165
2011 5,856 1,856 7,713 -48,453
2012 -1,531 -1,273 -2,804 -51,257
2013 -2,058 -907 -2,964 -54,221
2014 -2,679 -630 -3,309 -57,530
2015 -2,633 -659 -3,292 -60,822
2016 -2,282 -1,243 -3,526 -64,348
2017 4,705 2,287 6,992 -57,356
2018 -1,028 -881 -1,909 -59,264
Average Water Budget over Simulation Period (1990-2018) Average -2,038 -6 -2,044
Total -59,105 -160 -59,264
Average Water Budget over Early Historical period (1993-2002) Average -3,506 -102 -3,608
Total -35,061 -1,023 -36,084
Average Water Budget over Late Historical period (2005-2015) Average -260 281 22
Total -2,856 3,096 239
Average Water Budget over Long Historical period (1993-2015) Average -2,001 122 -1,879
Total -46,027 2,807 -43,220
Average Water Budget over Current period (2008-2018)
Average -1,123 0 -1,123
Total -12,358 0 -12,358
Simulation
Year
Net Change in Groundwater in Storage
Annual Change in
Groundwater in
Storage
Cumulative
Storage Change
Table 11 - Bedford/Coldwater GW Basin Water Balance (in acre-feet per year) - Projected Future Baseline Scenario

INFLOWS OUTFLOWS
Surface
Recharge GW-SW
Mountain
Front
Recharge
Net Quarry
Ops
WRF Perc
Ponds
Boundary
Inflow Total Inflow Wells
Net Quarry
Ops GW-SW ET
Boundary
Outflow Total Outflow
2019 7,126 16,193 1,580 107 1,856 71 26,933 4,319 2,911 1,486 1,278 660 10,654 16,279 16,279 2020 1,173 1,667 1,581 151 1,856 88 6,515 4,330 2,546 1,285 975 602 9,736 -3,221 13,058 2021 3,514 7,565 1,578 128 1,856 83 14,723 4,318 2,647 1,410 1,142 662 10,179 4,544 17,602 2022 905 1,120 1,587 173 1,856 91 5,732 4,333 2,358 1,008 923 524 9,146 -3,414 14,188 2023 1,089 1,008 1,592 185 1,856 91 5,822 4,330 2,220 795 850 451 8,646 -2,824 11,364 2024 4,977 10,445 1,436 118 1,856 77 18,908 4,326 2,652 1,357 1,159 669 10,163 8,744 20,108 2025 852 1,005 1,335 167 1,856 91 5,306 4,333 2,392 957 906 539 9,128 -3,822 16,287 2026 1,189 1,122 1,040 184 1,856 90 5,480 4,326 2,225 632 739 430 8,351 -2,871 13,416 2027 2,199 5,764 979 159 1,856 84 11,040 4,321 2,383 807 782 519 8,812 2,228 15,644 2028 526 652 1,097 194 1,856 92 4,417 4,335 2,179 580 656 409 8,158 -3,742 11,902 2029 2,586 5,375 887 159 1,856 84 10,947 4,315 2,293 615 764 492 8,479 2,468 14,370 2030 923 760 678 194 1,856 88 4,500 4,329 2,152 429 618 386 7,915 -3,415 10,955 2031 9,183 19,552 1,292 82 1,856 63 32,029 4,316 2,934 2,000 1,620 760 11,630 20,399 31,354 2032 1,672 2,232 1,673 136 1,856 83 7,652 4,324 2,667 1,633 1,152 701 10,476 -2,824 28,530 2033 457 1,082 1,612 183 1,856 91 5,281 4,332 2,320 1,051 847 474 9,023 -3,743 24,787 2034 473 934 1,498 194 1,856 91 5,047 4,321 2,161 865 665 389 8,402 -3,355 21,432 2035 1,529 2,031 1,426 182 1,856 84 7,108 4,324 2,183 774 709 424 8,413 -1,305 20,126 2036 3,554 8,626 1,055 133 1,856 80 15,304 4,324 2,577 1,055 966 614 9,535 5,768 25,895 2037 4,546 10,266 1,117 110 1,856 79 17,975 4,319 2,767 1,460 1,206 718 10,470 7,505 33,400 2038 985 1,013 1,313 168 1,856 91 5,426 4,326 2,400 963 922 529 9,139 -3,713 29,687 2039 726 780 1,322 189 1,856 91 4,965 4,334 2,207 718 755 423 8,436 -3,472 26,215 2040 973 652 1,296 199 1,856 92 5,066 4,332 2,094 507 698 374 8,005 -2,938 23,277 2041 1,240 549 980 195 1,856 92 4,911 4,331 2,065 372 614 359 7,740 -2,829 20,448 2042 920 477 405 205 1,856 92 3,955 4,329 2,015 244 543 331 7,461 -3,507 16,942 2043 3,490 8,003 461 152 1,856 80 14,042 4,327 2,363 560 773 510 8,533 5,509 22,450 2044 7,064 15,871 1,102 99 1,856 71 26,063 4,328 2,855 1,696 1,396 739 11,014 15,050 37,500 2045 1,172 1,713 1,539 150 1,856 87 6,518 4,330 2,578 1,354 1,005 613 9,880 -3,362 34,138 2046 3,514 7,700 1,843 126 1,856 83 15,122 4,318 2,669 1,546 1,195 675 10,403 4,719 38,856 2047 901 1,306 2,055 167 1,856 91 6,377 4,349 2,427 1,221 1,008 545 9,550 -3,173 35,683 2048 1,080 1,183 1,799 182 1,887 93 6,224 4,398 2,340 966 936 485 9,125 -2,902 32,781 2049 5,091 10,927 1,443 116 1,897 77 19,551 4,399 2,763 1,525 1,247 696 10,631 8,921 41,702 2050 819 1,088 1,339 169 1,897 93 5,405 4,406 2,481 1,048 953 557 9,445 -4,040 37,662 2051 1,187 1,346 1,043 184 1,897 92 5,748 4,400 2,314 722 781 450 8,667 -2,919 34,743 2052 2,200 6,108 982 156 1,887 85 11,418 4,388 2,475 894 830 564 9,152 2,266 37,009 2053 481 713 1,105 196 1,897 93 4,485 4,407 2,257 641 687 441 8,432 -3,948 33,061 2054 2,625 5,771 891 158 1,897 85 11,427 4,389 2,401 699 808 532 8,829 2,597 35,659 2055 910 944 678 193 1,897 90 4,712 4,403 2,245 510 657 421 8,236 -3,524 32,135 2056 9,323 20,087 1,301 78 1,887 65 32,740 4,383 3,030 2,213 1,713 797 12,136 20,604 52,739 2057 1,661 2,378 1,688 137 1,897 85 7,846 4,396 2,729 1,723 1,190 733 10,772 -2,926 49,813 2058 414 1,141 1,622 186 1,897 93 5,352 4,405 2,389 1,113 872 492 9,271 -3,920 45,893 2059 428 981 1,508 197 1,897 93 5,104 4,394 2,233 919 683 400 8,630 -3,526 42,367 2060 1,523 2,348 1,429 178 1,887 85 7,450 4,392 2,285 839 745 467 8,728 -1,278 41,090 2061 3,639 8,910 1,050 133 1,897 81 15,710 4,397 2,669 1,154 1,007 648 9,875 5,835 46,925 2062 4,601 10,532 1,112 111 1,897 81 18,333 4,392 2,854 1,569 1,254 746 10,815 7,517 54,442 2063 952 1,078 1,323 175 1,687 93 5,309 4,411 2,274 1,032 948 546 9,211 -3,902 50,540 2064 685 837 1,331 193 1,887 93 5,026 4,401 2,257 777 779 434 8,649 -3,623 46,917 2065 940 738 1,309 201 1,897 93 5,178 4,404 2,165 562 721 387 8,239 -3,061 43,856 2066 1,204 656 986 195 1,897 93 5,032 4,404 2,150 419 637 384 7,995 -2,963 40,893 2067 881 565 401 206 1,897 94 4,043 4,402 2,104 275 564 353 7,698 -3,654 37,238 2068 3,528 8,291 458 152 1,887 82 14,398 4,394 2,464 620 810 534 8,822 5,576 42,815 Average Water Budget over Simulation Period (2019-2068) Average 2,273 4,442 1,243 162 1,868 86 10,073 4,357 2,422 992 914 532 9,217 856 Total 113,627 222,085 62,156 8,086 93,385 4,313 503,652 217,845 121,121 49,597 45,687 26,587 460,838 42,815 Average Water Budget over Implementation Period (2022-2041) Average 2,029 3,748 1,261 165 1,856 86 9,146 4,326 2,362 929 877 509 9,003 142 Total 40,583 74,968 25,213 3,304 37,120 1,728 182,915 86,528 47,231 18,577 17,549 10,183 180,069 2,846 Average Water Budget over Sustainability Period (2042-2068) Average 2,268 4,507 1,193 163 1,878 87 10,095 4,383 2,437 994 916 536 9,267 828 Total 61,232 121,692 32,204 4,396 50,698 2,344 272,566 118,350 65,788 26,840 24,743 14,481 250,200 22,366 Average Water Budget over GSP Period (2019-2021)
Average 3,937 8,475 1,580 128 1,856 80 16,057 4,322 2,701 1,394 1,132 641 10,190 5,867 Total 11,812 25,425 4,740 385 5,568 241 48,171 12,967 8,103 4,181 3,395 1,923 30,569 17,602 Cumulative
Storage Change
Simulation
Year
Annual Storage
Change
Table 12 - Bedford MA Water Balance (in acre-feet per year) - Projected Future Baseline Scenario

INFLOWS OUTFLOWS
Surface
Recharge GW-SW
Quarry
Recharge
Mountain
Front
Recharge
WRF Perc
Ponds
Boundary
Inflow Total Inflow Wells GW-SW
Quarry
Outflow ET
Boundary
Outflow Total Outflow
2019 4,825 3,730 107 1,008 1,856 71 11,597 1,310 1,479 2,911 1,125 514 7,339 4,258 4,258 2020 799 1,440 151 1,008 1,856 88 5,341 1,307 1,284 2,546 828 494 6,459 -1,118 3,140 2021 2,312 2,389 128 1,007 1,856 83 7,775 1,309 1,407 2,647 992 558 6,913 862 4,001 2022 622 1,070 173 1,010 1,856 91 4,823 1,305 1,008 2,358 766 439 5,876 -1,053 2,948 2023 758 887 185 1,012 1,856 91 4,791 1,303 795 2,220 685 369 5,373 -582 2,367 2024 3,335 2,923 118 905 1,856 77 9,214 1,312 1,351 2,652 1,005 571 6,891 2,323 4,689 2025 598 1,004 167 846 1,856 91 4,562 1,305 957 2,392 751 461 5,867 -1,305 3,385 2026 769 798 184 653 1,856 90 4,351 1,304 632 2,225 587 358 5,106 -754 2,630 2027 1,428 2,282 159 613 1,856 84 6,421 1,306 806 2,383 643 442 5,580 841 3,471 2028 354 652 194 668 1,856 92 3,816 1,303 580 2,179 508 344 4,914 -1,099 2,372 2029 1,695 1,843 159 518 1,856 84 6,155 1,306 614 2,293 615 416 5,245 910 3,283 2030 619 624 194 377 1,856 88 3,758 1,303 429 2,152 467 317 4,668 -910 2,372 2031 6,177 4,284 82 788 1,856 63 13,251 1,313 1,990 2,934 1,455 654 8,346 4,905 7,277 2032 1,101 1,682 136 1,015 1,856 83 5,873 1,309 1,632 2,667 1,012 638 7,258 -1,385 5,893 2033 299 1,082 183 973 1,856 91 4,485 1,303 1,051 2,320 701 442 5,817 -1,332 4,560 2034 314 934 194 918 1,856 91 4,308 1,302 865 2,161 532 364 5,225 -917 3,643 2035 964 1,276 182 877 1,856 84 5,238 1,304 773 2,183 568 388 5,216 22 3,666 2036 2,336 2,744 133 628 1,856 80 7,777 1,309 1,051 2,577 811 564 6,312 1,465 5,131 2037 3,023 2,732 110 699 1,856 79 8,499 1,310 1,457 2,767 1,061 662 7,257 1,243 6,374 2038 697 1,013 168 819 1,856 91 4,645 1,305 963 2,400 767 504 5,939 -1,294 5,079 2039 509 780 189 823 1,856 91 4,248 1,303 718 2,207 601 411 5,240 -991 4,088 2040 661 594 199 819 1,856 92 4,220 1,303 507 2,094 533 364 4,801 -581 3,507 2041 861 494 195 624 1,856 92 4,121 1,303 372 2,065 456 343 4,538 -417 3,091 2042 621 397 205 270 1,856 92 3,442 1,302 244 2,015 378 309 4,247 -805 2,286 2043 2,305 2,556 152 313 1,856 80 7,263 1,307 559 2,363 606 466 5,300 1,963 4,248 2044 4,780 3,528 99 720 1,856 71 11,053 1,313 1,690 2,855 1,233 674 7,764 3,289 7,537 2045 798 1,486 150 981 1,856 87 5,359 1,307 1,354 2,578 859 587 6,685 -1,326 6,211 2046 2,312 2,433 126 1,168 1,856 83 7,978 1,309 1,543 2,669 1,044 655 7,220 758 6,970 2047 620 1,256 167 1,281 1,856 95 5,275 1,310 1,221 2,427 851 545 6,354 -1,078 5,891 2048 754 1,053 182 1,131 1,887 103 5,110 1,325 965 2,340 767 485 5,882 -772 5,119 2049 3,417 3,052 116 918 1,897 77 9,477 1,333 1,519 2,763 1,091 681 7,388 2,090 7,209 2050 580 1,088 169 855 1,897 102 4,691 1,327 1,048 2,481 795 557 6,208 -1,517 5,692 2051 771 992 184 663 1,897 111 4,618 1,326 722 2,314 628 450 5,440 -823 4,869 2052 1,431 2,460 156 623 1,887 98 6,655 1,328 893 2,475 688 564 5,948 707 5,576 2053 327 713 196 681 1,897 120 3,934 1,325 641 2,257 538 441 5,200 -1,267 4,309 2054 1,725 2,082 158 528 1,897 100 6,488 1,329 698 2,401 656 532 5,617 872 5,181 2055 614 781 193 384 1,897 110 3,979 1,325 510 2,245 503 421 5,005 -1,026 4,155 2056 6,274 4,461 78 802 1,887 65 13,566 1,334 2,202 3,030 1,546 769 8,880 4,686 8,841 2057 1,097 1,783 137 1,031 1,897 103 6,047 1,330 1,722 2,729 1,048 733 7,562 -1,515 7,326 2058 274 1,141 186 985 1,897 149 4,631 1,325 1,113 2,389 724 492 6,044 -1,413 5,912 2059 287 981 197 931 1,897 160 4,452 1,324 919 2,233 548 400 5,425 -973 4,940 2060 961 1,531 178 884 1,887 139 5,581 1,325 839 2,285 601 467 5,517 64 5,004 2061 2,398 2,849 133 628 1,897 113 8,018 1,330 1,151 2,669 850 648 6,649 1,369 6,373 2062 3,058 2,844 111 699 1,897 103 8,712 1,332 1,566 2,854 1,106 746 7,604 1,108 7,481 2063 679 1,078 175 833 1,687 154 4,607 1,340 1,032 2,274 790 546 5,981 -1,375 6,106 2064 484 837 193 837 1,887 171 4,409 1,324 777 2,257 622 434 5,414 -1,006 5,100 2065 643 666 201 835 1,897 173 4,415 1,325 562 2,165 554 387 4,992 -577 4,523 2066 840 592 195 636 1,897 166 4,325 1,325 419 2,150 476 384 4,755 -429 4,094 2067 599 473 206 274 1,897 161 3,609 1,324 275 2,104 396 353 4,451 -842 3,252 2068 2,334 2,704 152 318 1,887 121 7,516 1,328 618 2,464 639 534 5,583 1,933 5,185 Average Water Budget over Simulation Period (2019-2068) Average 1,521 1,661 162 776 1,868 102 6,090 1,315 990 2,422 760 498 5,986 104 Total 76,037 83,075 8,086 38,820 93,385 5,077 304,480 65,768 49,519 121,121 38,010 24,878 299,295 5,185 Average Water Budget over Implementation Period (2022-2041) Average 1,356 1,485 165 779 1,856 86 5,728 1,305 927 2,362 726 453 5,773 -46 Total 27,119 29,699 3,304 15,588 37,120 1,728 114,557 26,109 18,550 47,231 14,525 9,052 115,468 -911 Average Water Budget over Sustainability Period (2042-2068) Average 1,518 1,697 163 748 1,878 115 6,119 1,323 993 2,437 761 528 6,041 78 Total 40,982 45,817 4,396 20,209 50,698 3,108 165,210 35,732 26,798 65,788 20,539 14,260 163,116 2,094 Average Water Budget over GSP Period (2019-2021)
Average 2,645 2,520 128 1,008 1,856 80 8,237 1,309 1,390 2,701 982 522 6,904 1,334 Total 7,936 7,559 385 3,023 5,568 241 24,712 3,926 4,170 8,103 2,945 1,566 20,711 4,001 Cumulative
Storage Change
Simulation
Year
Annual Storage
Change
Table 13 - Coldwater MA Water Balance (in acre-feet per year) - Projected Future Baseline Scenario

INFLOWS OUTFLOWS
Surface
Recharge GW-SW
Mountain
Front
Recharge
Net Quarry
Ops
Boundary
Inflow Total Inflow Wells
Net Quarry
Ops GW-SW ET
Boundary
Outflow Total Outflow
2019 2,301 12,463 572 0 145 15,481 3,009 0 7 153 0 3,169 12,312 12,312 2020 374 227 573 0 108 1,282 3,023 0 0 146 0 3,169 -1,887 10,425 2021 1,202 5,176 571 0 104 7,053 3,009 0 3 151 0 3,162 3,891 14,315 2022 283 50 577 0 85 994 3,028 0 0 157 0 3,185 -2,191 12,124 2023 331 121 580 0 82 1,113 3,026 0 0 165 0 3,192 -2,079 10,045 2024 1,642 7,522 530 0 98 9,792 3,015 0 6 153 0 3,174 6,618 16,664 2025 254 0 490 0 78 822 3,028 0 0 155 0 3,183 -2,362 14,302 2026 420 323 386 0 72 1,201 3,022 0 0 151 0 3,173 -1,972 12,330 2027 771 3,482 366 0 77 4,696 3,015 0 1 139 0 3,155 1,541 13,870 2028 172 0 429 0 65 666 3,031 0 0 147 0 3,179 -2,512 11,358 2029 891 3,533 369 0 76 4,868 3,009 0 1 149 0 3,159 1,709 13,066 2030 304 137 301 0 70 812 3,026 0 0 151 0 3,177 -2,365 10,701 2031 3,006 15,268 504 0 105 18,883 3,003 0 11 164 0 3,178 15,704 26,405 2032 571 549 658 0 62 1,841 3,015 0 2 140 0 3,156 -1,315 25,091 2033 157 0 638 0 33 828 3,028 0 0 145 0 3,174 -2,345 22,745 2034 159 0 579 0 25 764 3,019 0 0 133 0 3,152 -2,388 20,357 2035 565 756 549 0 35 1,905 3,021 0 0 141 0 3,162 -1,257 19,100 2036 1,217 5,882 428 0 51 7,577 3,015 0 3 155 0 3,173 4,404 23,505 2037 1,523 7,535 418 0 56 9,531 3,009 0 3 145 0 3,157 6,374 29,879 2038 288 0 493 0 24 806 3,021 0 0 155 0 3,176 -2,370 27,509 2039 217 0 499 0 11 728 3,031 0 0 154 0 3,185 -2,458 25,051 2040 312 57 477 0 10 856 3,029 0 0 165 0 3,193 -2,337 22,714 2041 380 55 356 0 16 806 3,028 0 0 158 0 3,186 -2,379 20,334 2042 299 79 134 0 22 535 3,027 0 0 165 1 3,193 -2,658 17,676 2043 1,185 5,447 148 0 44 6,823 3,020 0 1 168 1 3,190 3,633 21,309 2044 2,284 12,343 382 0 65 15,075 3,015 0 7 163 0 3,184 11,892 33,201 2045 374 227 558 0 26 1,184 3,023 0 0 146 0 3,169 -1,985 31,216 2046 1,202 5,267 675 0 20 7,164 3,009 0 3 151 0 3,164 4,000 35,216 2047 281 50 774 0 0 1,105 3,039 0 0 158 3 3,200 -2,095 33,121 2048 325 130 669 0 0 1,124 3,074 0 0 169 10 3,253 -2,129 30,991 2049 1,674 7,875 525 0 16 10,090 3,066 0 6 155 0 3,227 6,863 37,854 2050 239 0 484 0 0 724 3,079 0 0 158 9 3,246 -2,523 35,331 2051 415 354 380 0 0 1,150 3,073 0 0 154 20 3,246 -2,097 33,235 2052 768 3,649 359 0 0 4,776 3,061 0 1 142 13 3,217 1,559 34,794 2053 154 0 424 0 0 578 3,083 0 0 149 27 3,259 -2,681 32,113 2054 901 3,689 363 0 0 4,953 3,061 0 1 152 14 3,227 1,726 33,839 2055 295 164 295 0 0 754 3,077 0 0 154 20 3,251 -2,497 31,341 2056 3,048 15,626 500 0 28 19,202 3,049 0 11 167 0 3,228 15,974 47,315 2057 564 596 657 0 0 1,816 3,066 0 2 142 18 3,228 -1,411 45,904 2058 140 0 636 0 0 777 3,080 0 0 148 56 3,283 -2,507 43,398 2059 142 0 577 0 0 719 3,070 0 0 135 67 3,272 -2,553 40,845 2060 563 817 545 0 0 1,924 3,067 0 0 144 54 3,265 -1,341 39,503 2061 1,241 6,062 422 0 0 7,725 3,066 0 3 157 32 3,258 4,466 43,969 2062 1,542 7,688 413 0 0 9,643 3,060 0 3 148 22 3,234 6,409 50,378 2063 273 0 490 0 0 763 3,072 0 0 158 61 3,290 -2,527 47,851 2064 200 0 494 0 0 695 3,078 0 0 157 77 3,312 -2,617 45,234 2065 297 72 473 0 0 842 3,080 0 0 167 80 3,327 -2,484 42,750 2066 364 64 351 0 0 779 3,079 0 0 161 73 3,313 -2,533 40,216 2067 283 91 127 0 0 501 3,078 0 0 168 69 3,316 -2,815 37,401 2068 1,194 5,587 141 0 0 6,922 3,067 0 2 170 42 3,280 3,641 41,043 Average Water Budget over Simulation Period (2019-2068) Average 752 2,780 467 0 34 4,033 3,042 0 2 154 15 3,212 821 Total 37,590 139,010 23,337 0 1,709 201,646 152,078 0 78 7,677 770 160,603 41,043 Average Water Budget over Implementation Period (2022-2041) Average 673 2,263 481 0 57 3,474 3,021 0 1 151 0 3,173 301 Total 13,464 45,269 9,625 0 1,131 69,489 60,419 0 27 3,024 0 63,470 6,019 Average Water Budget over Sustainability Period (2042-2068) Average 750 2,810 444 0 8 4,013 3,060 0 2 156 29 3,246 767 Total 20,250 75,875 11,995 0 221 108,341 82,618 0 41 4,204 770 87,633 20,708 Average Water Budget over GSP Period (2019-2021)
Average 1,292 5,955 572 0 119 7,939 3,014 0 3 150 0 3,167 4,772 Total 3,877 17,865 1,716 0 357 23,816 9,041 0 10 450 0 9,501 14,315 Cumulative
Storage Change
Simulation
Year
Annual
Storage
Change
Table 14 - Change in Groundwater in Storage (in acre-feet per year) - Projected Future Baseline Scenario Coldwater
Hydrologic Area
Bedford Hydrologic
Area
2019 12,312 3,967 16,279 16,279
2020 -1,887 -1,334 -3,221 13,058
2021 3,891 654 4,544 17,602
2022 -2,191 -1,223 -3,414 14,188
2023 -2,079 -745 -2,824 11,364
2024 6,618 2,126 8,744 20,108
2025 -2,362 -1,460 -3,822 16,287
2026 -1,972 -898 -2,871 13,416
2027 1,541 687 2,228 15,644
2028 -2,512 -1,229 -3,742 11,902
2029 1,709 759 2,468 14,369
2030 -2,365 -1,050 -3,415 10,954
2031 15,704 4,695 20,399 31,353
2032 -1,315 -1,509 -2,824 28,529
2033 -2,345 -1,397 -3,743 24,786
2034 -2,388 -967 -3,355 21,431
2035 -1,257 -48 -1,305 20,126
2036 4,404 1,364 5,768 25,894
2037 6,374 1,131 7,505 33,399
2038 -2,370 -1,343 -3,713 29,686
2039 -2,458 -1,014 -3,472 26,215
2040 -2,337 -601 -2,938 23,276
2041 -2,379 -449 -2,829 20,448
2042 -2,658 -854 -3,512 16,936
2043 3,633 1,874 5,506 22,442
2044 11,892 3,158 15,050 37,491
2045 -1,985 -1,377 -3,362 34,129
2046 4,000 718 4,719 38,848
2047 -2,095 -1,078 -3,173 35,674
2048 -2,129 -772 -2,902 32,773
2049 6,863 2,058 8,921 41,693
2050 -2,523 -1,517 -4,040 37,654
2051 -2,097 -823 -2,919 34,734
2052 1,559 707 2,266 37,000
2053 -2,681 -1,267 -3,948 33,053
2054 1,726 872 2,597 35,650
2055 -2,497 -1,027 -3,524 32,126
2056 15,974 4,630 20,604 52,730
2057 -1,411 -1,515 -2,926 49,803
2058 -2,507 -1,413 -3,920 45,883
2059 -2,553 -973 -3,526 42,358
2060 -1,341 64 -1,278 41,080
2061 4,466 1,369 5,835 46,915
2062 6,409 1,108 7,517 54,432
2063 -2,527 -1,375 -3,902 50,530
2064 -2,617 -1,006 -3,623 46,908
2065 -2,484 -577 -3,061 43,846
2066 -2,533 -429 -2,963 40,884
2067 -2,815 -847 -3,662 37,222
2068 3,641 1,931 5,572 42,794
Average Water Budget over Simulation Period (2019-2068) Average 821 35 856
Total 41,043 1,751 42,794
Average Water Budget over Implementation Period (2022-2041) Average 301 -159 142
Total 6,019 -3,173 2,846
Average Water Budget over Sustainability Period (2042-2068) Average 767 61 828
Total 20,708 1,638 22,346
Average Water Budget over GSP Period (2019-2021)
Average 4,772 1,096 5,867
Total 14,315 3,287 17,602
Simulation
Year
Net Change in Groundwater in Storage
Annual Change in
Groundwater in
Storage
Cumulative
Storage Change
Table 15 - Bedford/Coldwater GW Basin Water Balance (in acre-feet per year) - Projected Future Growth plus Climate Change Scenario

INFLOWS OUTFLOWS
Surface
Recharge GW-SW
Mountain
Front
Recharge
Net Quarry
Ops
WRF Perc
Ponds
Boundary
Inflow Total Inflow Wells
Net Quarry
Ops GW-SW ET
Boundary
Outflow Total Outflow
2019 8,073 16,119 1,632 299 2,139 71 28,334 5,021 2,866 1,737 1,553 607 11,784 16,549 16,549 2020 1,871 1,689 1,632 456 2,139 88 7,874 5,019 2,504 1,637 1,216 551 10,927 -3,053 13,497 2021 4,391 7,441 1,628 409 2,139 83 16,091 5,018 2,595 1,838 1,480 572 11,503 4,588 18,085 2022 1,545 1,258 1,637 490 2,139 91 7,160 5,027 2,405 1,396 1,143 476 10,445 -3,285 14,800 2023 1,743 1,172 1,642 510 2,139 91 7,298 5,028 2,321 1,142 1,076 398 9,965 -2,668 12,132 2024 5,728 10,357 1,470 380 2,139 77 20,151 5,016 2,658 1,837 1,543 605 11,660 8,492 20,624 2025 1,343 1,112 1,344 486 2,139 91 6,516 5,026 2,408 1,316 1,124 496 10,371 -3,855 16,768 2026 1,939 1,359 1,069 512 2,139 90 7,108 5,025 2,322 997 955 373 9,673 -2,564 14,204 2027 3,177 5,660 1,045 472 2,139 84 12,578 5,010 2,420 1,285 1,057 442 10,213 2,364 16,568 2028 910 824 1,185 528 2,139 92 5,678 5,021 2,292 940 853 361 9,466 -3,788 12,780 2029 3,419 5,353 975 475 2,139 84 12,445 5,009 2,358 1,033 1,055 401 9,856 2,589 15,370 2030 1,563 999 779 523 2,139 88 6,092 5,024 2,289 817 863 334 9,327 -3,235 12,134 2031 10,087 19,400 1,313 304 2,139 63 33,306 5,019 2,885 2,591 2,221 717 13,432 19,874 32,009 2032 2,152 2,186 1,613 432 2,139 83 8,606 5,021 2,590 2,048 1,442 644 11,744 -3,138 28,871 2033 838 1,097 1,503 518 2,139 91 6,187 5,022 2,348 1,284 987 418 10,059 -3,872 24,999 2034 842 950 1,400 542 2,139 91 5,965 5,020 2,244 1,049 770 320 9,403 -3,438 21,561 2035 2,277 2,241 1,322 513 2,139 84 8,577 5,012 2,301 1,067 884 367 9,630 -1,053 20,507 2036 4,385 8,461 1,048 416 2,139 80 16,529 5,017 2,562 1,470 1,292 535 10,877 5,652 26,159 2037 5,604 10,141 1,131 370 2,139 79 19,465 5,014 2,705 1,976 1,647 634 11,976 7,489 33,648 2038 1,490 1,153 1,327 488 2,139 91 6,689 5,026 2,415 1,356 1,138 487 10,423 -3,734 29,915 2039 1,144 912 1,343 528 2,139 91 6,159 5,023 2,288 1,038 927 359 9,635 -3,476 26,438 2040 1,555 817 1,324 515 2,139 92 6,442 5,030 2,237 819 887 276 9,249 -2,808 23,631 2041 1,869 796 1,026 529 2,139 92 6,452 5,018 2,213 726 821 286 9,064 -2,612 21,019 2042 1,517 642 482 542 2,139 93 5,415 5,029 2,197 548 751 271 8,796 -3,381 17,638 2043 4,321 7,838 537 448 2,139 80 15,364 5,021 2,427 958 1,105 424 9,935 5,429 23,066 2044 7,992 15,635 1,143 330 2,139 71 27,310 5,020 2,831 2,272 1,939 674 12,737 14,574 37,640 2045 1,874 1,766 1,570 454 2,139 87 7,891 5,019 2,532 1,804 1,303 569 11,226 -3,335 34,305 2046 4,391 7,564 1,856 406 2,139 83 16,439 5,019 2,616 2,008 1,556 587 11,786 4,653 38,958 2047 1,538 1,399 2,048 486 2,139 91 7,701 5,046 2,440 1,640 1,229 505 10,861 -3,159 35,799 2048 1,717 1,380 1,817 512 2,176 93 7,695 5,104 2,407 1,352 1,171 450 10,484 -2,789 33,010 2049 5,802 10,901 1,480 380 2,197 77 20,836 5,100 2,749 2,042 1,632 639 12,163 8,674 41,684 2050 1,267 1,175 1,358 495 2,197 93 6,585 5,110 2,481 1,413 1,163 521 10,687 -4,102 37,582 2051 1,912 1,614 1,072 517 2,197 92 7,403 5,109 2,402 1,100 999 399 10,008 -2,605 34,977 2052 3,151 5,993 1,043 471 2,176 85 12,920 5,086 2,494 1,385 1,104 487 10,557 2,363 37,339 2053 819 877 1,188 540 2,197 93 5,715 5,105 2,353 1,004 879 389 9,730 -4,015 33,324 2054 3,438 5,762 981 475 2,197 85 12,938 5,093 2,450 1,134 1,094 442 10,213 2,725 36,049 2055 1,522 1,214 783 529 2,197 90 6,334 5,108 2,370 903 902 374 9,657 -3,322 32,726 2056 10,185 20,021 1,321 294 2,176 65 34,062 5,102 2,969 2,827 2,323 764 13,985 20,077 52,803 2057 2,105 2,442 1,629 439 2,197 85 8,897 5,104 2,659 2,167 1,493 683 12,107 -3,210 49,593 2058 750 1,154 1,520 529 2,197 93 6,243 5,105 2,416 1,360 1,012 448 10,341 -4,097 45,495 2059 751 989 1,413 554 2,197 93 5,997 5,104 2,311 1,101 786 334 9,637 -3,639 41,856 2060 2,247 2,545 1,333 512 2,176 85 8,898 5,088 2,375 1,150 921 401 9,936 -1,037 40,819 2061 4,436 8,786 1,039 419 2,197 81 16,958 5,101 2,639 1,580 1,346 571 11,237 5,722 46,540 2062 5,639 10,443 1,122 372 2,197 81 19,854 5,098 2,795 2,086 1,698 669 12,346 7,508 54,049 2063 1,415 1,199 1,337 498 2,197 93 6,739 5,110 2,479 1,422 1,164 509 10,684 -3,945 50,103 2064 1,060 954 1,346 540 2,176 93 6,169 5,100 2,337 1,082 948 372 9,839 -3,670 46,433 2065 1,481 919 1,330 553 2,197 93 6,574 5,112 2,288 880 906 315 9,501 -2,927 43,506 2066 1,793 934 1,027 539 2,197 93 6,584 5,102 2,289 800 847 315 9,354 -2,770 40,736 2067 1,437 799 476 550 2,197 94 5,553 5,113 2,275 614 783 299 9,083 -3,530 37,206 2068 4,323 8,167 530 451 2,176 82 15,728 5,098 2,508 1,050 1,146 475 10,277 5,451 42,657 Average Water Budget over Simulation Period (2019-2068) Average 2,937 4,492 1,263 471 2,161 86 11,410 5,055 2,466 1,382 1,183 471 10,557 853 Total 146,828 224,610 63,167 23,530 108,057 4,314 570,506 252,772 123,318 69,080 59,134 23,544 527,849 42,657 Average Water Budget over Implementation Period (2022-2041) Average 2,680 3,812 1,275 477 2,139 86 10,470 5,020 2,413 1,309 1,134 446 10,323 147 Total 53,609 76,249 25,495 9,532 42,790 1,728 209,402 100,408 48,262 26,185 22,684 8,930 206,469 2,934 Average Water Budget over Sustainability Period (2042-2068) Average 2,922 4,560 1,214 475 2,180 87 11,437 5,085 2,485 1,396 1,193 477 10,636 801 Total 78,884 123,112 32,780 12,835 58,849 2,345 308,804 137,306 67,091 37,684 32,201 12,885 287,166 21,638 Average Water Budget over GSP Period (2019-2021)
Average 4,778 8,416 1,631 388 2,139 80 17,433 5,019 2,655 1,737 1,417 577 11,405 6,028 Total 14,335 25,249 4,892 1,164 6,418 241 52,299 15,058 7,965 5,211 4,250 1,730 34,214 18,085 Cumulative
Storage Change
Simulation
Year
Annual Storage
Change
Table 16 - Bedford MA Water Balance (in acre-feet per year) - Projected Future Growth plus Climate Change Scenario

INFLOWS OUTFLOWS
Surface
Recharge GW-SW
Quarry
Recharge
Mountain
Front
Recharge
WRF Perc
Ponds
Boundary
Inflow Total Inflow Wells GW-SW
Quarry
Outflow ET
Boundary
Outflow Total Outflow
2019 5,577 3,665 299 1,082 2,139 71 12,833 1,895 1,730 2,866 1,388 453 8,332 4,501 4,501 2020 1,355 1,462 456 1,081 2,139 88 6,581 1,883 1,637 2,504 1,055 429 7,508 -927 3,574 2021 3,032 2,266 409 1,080 2,139 83 9,009 1,884 1,835 2,595 1,315 448 8,078 932 4,506 2022 1,125 1,210 490 1,083 2,139 91 6,138 1,880 1,396 2,405 972 372 7,025 -888 3,618 2023 1,285 1,052 510 1,085 2,139 91 6,163 1,882 1,142 2,321 895 298 6,538 -375 3,243 2024 3,966 2,841 380 965 2,139 77 10,368 1,888 1,831 2,658 1,375 485 8,238 2,130 5,373 2025 996 1,111 486 885 2,139 91 5,709 1,881 1,316 2,408 952 402 6,959 -1,250 4,123 2026 1,359 1,036 512 712 2,139 90 5,848 1,879 997 2,322 791 281 6,270 -422 3,701 2027 2,181 2,180 472 696 2,139 84 7,752 1,881 1,283 2,420 905 341 6,830 922 4,623 2028 656 824 528 764 2,139 92 5,003 1,879 940 2,292 691 276 6,078 -1,074 3,548 2029 2,383 1,824 475 605 2,139 84 7,511 1,880 1,032 2,358 891 304 6,466 1,045 4,593 2030 1,118 863 523 469 2,139 88 5,201 1,882 817 2,289 697 244 5,929 -728 3,865 2031 6,947 4,146 304 822 2,139 63 14,422 1,891 2,581 2,885 2,041 589 9,987 4,435 8,300 2032 1,550 1,641 432 1,005 2,139 83 6,851 1,884 2,046 2,590 1,289 563 8,373 -1,522 6,778 2033 595 1,097 518 943 2,139 91 5,383 1,879 1,284 2,348 828 370 6,709 -1,325 5,453 2034 600 950 542 903 2,139 91 5,226 1,878 1,049 2,244 626 280 6,076 -849 4,603 2035 1,580 1,486 513 868 2,139 84 6,670 1,878 1,067 2,301 730 309 6,284 385 4,989 2036 3,004 2,586 416 686 2,139 80 8,912 1,883 1,467 2,562 1,122 461 7,496 1,416 6,405 2037 3,878 2,612 370 751 2,139 79 9,829 1,886 1,973 2,705 1,487 556 8,607 1,223 7,627 2038 1,110 1,153 488 861 2,139 91 5,843 1,880 1,356 2,415 969 444 7,063 -1,220 6,407 2039 839 912 528 871 2,139 91 5,381 1,878 1,038 2,288 758 329 6,292 -910 5,497 2040 1,126 760 515 870 2,139 92 5,503 1,879 819 2,237 707 246 5,889 -386 5,111 2041 1,392 744 529 692 2,139 92 5,588 1,878 726 2,213 648 246 5,712 -123 4,988 2042 1,094 565 542 359 2,139 93 4,793 1,878 548 2,197 570 222 5,416 -623 4,365 2043 3,017 2,399 448 402 2,139 80 8,486 1,882 957 2,427 922 351 6,538 1,948 6,312 2044 5,514 3,300 330 790 2,139 71 12,145 1,892 2,266 2,831 1,763 585 9,336 2,808 9,121 2045 1,358 1,540 454 1,046 2,139 87 6,625 1,883 1,803 2,532 1,143 524 7,884 -1,259 7,862 2046 3,032 2,299 406 1,219 2,139 83 9,178 1,884 2,006 2,616 1,391 544 8,441 738 8,600 2047 1,121 1,350 486 1,319 2,139 91 6,507 1,888 1,640 2,440 1,059 487 7,514 -1,007 7,593 2048 1,274 1,250 512 1,185 2,176 93 6,490 1,910 1,352 2,407 987 438 7,093 -603 6,989 2049 4,026 3,023 380 981 2,197 77 10,683 1,919 2,037 2,749 1,462 600 8,767 1,916 8,905 2050 952 1,175 495 903 2,197 93 5,815 1,911 1,413 2,481 988 511 7,304 -1,489 7,416 2051 1,351 1,253 517 722 2,197 92 6,131 1,910 1,100 2,402 832 394 6,637 -506 6,910 2052 2,172 2,343 471 700 2,176 85 7,948 1,910 1,384 2,494 949 471 7,209 740 7,650 2053 601 877 540 772 2,197 98 5,086 1,909 1,004 2,353 715 389 6,371 -1,285 6,365 2054 2,407 2,078 475 615 2,197 85 7,858 1,911 1,133 2,450 928 431 6,854 1,004 7,369 2055 1,101 1,046 529 478 2,197 90 5,441 1,913 903 2,370 734 369 6,288 -848 6,521 2056 7,020 4,413 294 832 2,176 65 14,800 1,926 2,817 2,969 2,140 713 10,566 4,234 10,756 2057 1,529 1,838 439 1,022 2,197 85 7,109 1,915 2,166 2,659 1,338 681 8,759 -1,650 9,106 2058 542 1,154 529 962 2,197 130 5,514 1,909 1,360 2,416 850 448 6,983 -1,469 7,637 2059 546 989 554 919 2,197 142 5,347 1,908 1,101 2,311 640 334 6,294 -947 6,690 2060 1,567 1,722 512 882 2,176 112 6,972 1,906 1,150 2,375 765 401 6,597 375 7,065 2061 3,050 2,727 419 681 2,197 86 9,161 1,914 1,577 2,639 1,173 571 7,874 1,286 8,351 2062 3,906 2,762 372 746 2,197 81 10,064 1,917 2,083 2,795 1,534 666 8,995 1,068 9,419 2063 1,068 1,199 498 874 2,197 131 5,967 1,911 1,422 2,479 992 509 7,312 -1,345 8,074 2064 788 954 540 878 2,176 149 5,485 1,906 1,082 2,337 776 372 6,474 -989 7,086 2065 1,085 847 553 880 2,197 149 5,712 1,908 880 2,288 723 315 6,114 -402 6,684 2066 1,349 869 539 698 2,197 138 5,790 1,908 800 2,289 672 315 5,985 -195 6,489 2067 1,048 705 550 360 2,197 129 4,990 1,909 614 2,275 599 299 5,695 -705 5,784 2068 3,026 2,579 451 402 2,176 88 8,722 1,910 1,048 2,508 960 475 6,901 1,821 7,604 Average Water Budget over Simulation Period (2019-2068) Average 2,064 1,714 471 828 2,161 93 7,331 1,895 1,380 2,466 1,015 423 7,179 152 Total 103,198 85,678 23,530 41,405 108,057 4,674 366,543 94,735 69,009 123,318 50,737 21,140 358,938 7,604 Average Water Budget over Implementation Period (2022-2041) Average 1,884 1,551 477 827 2,139 86 6,965 1,881 1,308 2,413 969 370 6,941 24 Total 37,689 31,029 9,532 16,534 42,790 1,728 139,301 37,625 26,161 48,262 19,376 7,395 138,819 482 Average Water Budget over Sustainability Period (2042-2068) Average 2,057 1,750 475 801 2,180 100 7,364 1,905 1,394 2,485 1,022 460 7,267 97 Total 55,545 47,256 12,835 21,628 58,849 2,705 198,818 51,447 37,646 67,091 27,603 12,415 196,202 2,617 Average Water Budget over GSP Period (2019-2021)
Average 3,321 2,465 388 1,081 2,139 80 9,474 1,887 1,734 2,655 1,253 443 7,973 1,502 Total 9,964 7,394 1,164 3,243 6,418 241 28,423 5,662 5,202 7,965 3,758 1,330 23,918 4,506 Cumulative
Storage Change
Simulation
Year
Annual Storage
Change
Table 17 - Coldwater MA Water Balance (in acre-feet per year) - Projected Future Growth plus Climate Change Scenario

INFLOWS OUTFLOWS
Surface
Recharge GW-SW
Mountain
Front
Recharge
Net Quarry
Ops
Boundary
Inflow Total Inflow Wells
Net Quarry
Ops GW-SW ET
Boundary
Outflow Total Outflow
2019 2,496 12,454 550 0 154 15,655 3,126 0 6 166 0 3,298 12,357 12,357 2020 516 227 551 0 122 1,415 3,136 0 0 161 0 3,297 -1,882 10,475 2021 1,359 5,175 548 0 123 7,205 3,134 0 2 165 0 3,302 3,903 14,378 2022 420 49 554 0 103 1,126 3,147 0 0 170 0 3,317 -2,191 12,187 2023 458 120 557 0 100 1,235 3,146 0 0 181 0 3,327 -2,092 10,095 2024 1,762 7,516 505 0 120 9,903 3,128 0 5 168 0 3,301 6,602 16,697 2025 348 0 459 0 95 902 3,146 0 0 172 0 3,318 -2,416 14,280 2026 580 323 357 0 92 1,353 3,146 0 0 165 0 3,310 -1,958 12,323 2027 996 3,480 350 0 102 4,928 3,129 0 1 151 0 3,281 1,646 13,969 2028 255 0 421 0 85 760 3,142 0 0 162 0 3,304 -2,544 11,426 2029 1,036 3,529 370 0 97 5,032 3,128 0 1 164 0 3,293 1,739 13,164 2030 445 136 310 0 91 982 3,142 0 0 165 0 3,308 -2,326 10,838 2031 3,139 15,254 491 0 127 19,011 3,128 0 10 179 0 3,317 15,694 26,532 2032 602 545 608 0 81 1,836 3,136 0 2 153 0 3,291 -1,455 25,078 2033 243 0 560 0 48 852 3,143 0 0 159 0 3,302 -2,450 22,627 2034 242 0 497 0 40 778 3,143 0 0 144 0 3,287 -2,509 20,118 2035 698 755 455 0 58 1,965 3,134 0 0 154 0 3,288 -1,323 18,795 2036 1,380 5,875 362 0 74 7,691 3,134 0 3 170 0 3,307 4,384 23,179 2037 1,726 7,530 380 0 78 9,714 3,128 0 3 160 0 3,291 6,423 29,602 2038 380 0 466 0 44 890 3,146 0 0 170 0 3,316 -2,426 27,177 2039 305 0 472 0 30 807 3,145 0 0 169 0 3,313 -2,506 24,670 2040 428 57 454 0 30 969 3,151 0 0 180 0 3,331 -2,362 22,309 2041 477 52 334 0 40 903 3,140 0 0 172 0 3,312 -2,409 19,899 2042 422 77 123 0 49 671 3,151 0 0 180 1 3,332 -2,661 17,239 2043 1,305 5,439 134 0 73 6,951 3,140 0 1 183 1 3,325 3,627 20,865 2044 2,479 12,334 353 0 89 15,255 3,129 0 6 177 0 3,312 11,943 32,809 2045 516 226 523 0 45 1,311 3,136 0 0 160 0 3,296 -1,985 30,823 2046 1,359 5,265 637 0 43 7,304 3,134 0 2 166 0 3,303 4,001 34,824 2047 417 48 729 0 18 1,213 3,158 0 0 171 0 3,329 -2,116 32,709 2048 444 130 632 0 12 1,218 3,194 0 0 184 0 3,379 -2,161 30,547 2049 1,776 7,878 499 0 39 10,192 3,181 0 6 170 0 3,357 6,835 37,382 2050 314 0 455 0 9 779 3,199 0 0 175 0 3,374 -2,595 34,788 2051 560 361 350 0 4 1,276 3,199 0 0 167 0 3,366 -2,090 32,698 2052 979 3,650 343 0 16 4,988 3,177 0 1 154 0 3,332 1,655 34,353 2053 218 0 416 0 0 634 3,195 0 0 164 5 3,364 -2,730 31,622 2054 1,031 3,684 366 0 11 5,091 3,181 0 1 167 0 3,349 1,742 33,365 2055 420 168 305 0 5 898 3,195 0 0 168 0 3,364 -2,465 30,900 2056 3,165 15,608 488 0 51 19,313 3,176 0 10 183 0 3,369 15,944 46,844 2057 576 605 607 0 2 1,791 3,189 0 2 155 0 3,346 -1,556 45,288 2058 208 0 559 0 0 766 3,196 0 0 162 37 3,395 -2,629 42,660 2059 205 0 494 0 0 700 3,196 0 0 147 49 3,392 -2,692 39,968 2060 680 823 451 0 0 1,954 3,182 0 0 157 27 3,366 -1,412 38,556 2061 1,386 6,060 357 0 0 7,803 3,187 0 3 172 5 3,368 4,435 42,991 2062 1,733 7,681 376 0 3 9,793 3,181 0 3 163 0 3,347 6,446 49,437 2063 346 0 463 0 0 810 3,199 0 0 173 38 3,410 -2,601 46,837 2064 272 0 468 0 0 739 3,193 0 0 172 56 3,421 -2,682 44,155 2065 396 72 450 0 0 918 3,204 0 0 182 56 3,443 -2,525 41,630 2066 444 65 329 0 0 838 3,193 0 0 176 45 3,414 -2,575 39,055 2067 389 94 116 0 0 599 3,204 0 0 184 38 3,426 -2,827 36,228 2068 1,297 5,587 128 0 0 7,012 3,188 0 2 186 8 3,383 3,628 39,856 Average Water Budget over Simulation Period (2019-2068) Average 873 2,779 435 0 48 4,135 3,161 0 1 168 7 3,337 797 Total 43,629 138,932 21,762 0 2,405 206,727 158,037 0 71 8,397 366 166,871 39,856 Average Water Budget over Implementation Period (2022-2041) Average 796 2,261 448 0 77 3,582 3,139 0 1 165 0 3,306 276 Total 15,920 45,220 8,961 0 1,535 71,636 62,783 0 25 3,307 0 66,115 5,521 Average Water Budget over Sustainability Period (2042-2068) Average 864 2,809 413 0 17 4,104 3,180 0 1 170 14 3,365 739 Total 23,338 75,856 11,152 0 470 110,816 85,859 0 37 4,598 366 90,859 19,957 Average Water Budget over GSP Period (2019-2021)
Average 1,457 5,952 550 0 133 8,092 3,132 0 3 164 0 3,299 4,793 Total 4,371 17,856 1,649 0 400 24,275 9,396 0 9 492 0 9,897 14,378 Cumulative
Storage Change
Simulation
Year
Annual
Storage
Change
Table 18 - Change in Groundwater in Storage (in acre-feet per year) - Projected Future Growth plus Climate Change Scenario Coldwater
Hydrologic Area
Bedford Hydrologic
Area
2019 12,357 4,193 16,549 16,549
2020 -1,882 -1,171 -3,053 13,497
2021 3,903 685 4,588 18,085
2022 -2,191 -1,094 -3,285 14,800
2023 -2,092 -575 -2,668 12,132
2024 6,602 1,890 8,492 20,624
2025 -2,416 -1,439 -3,855 16,768
2026 -1,958 -607 -2,564 14,204
2027 1,646 718 2,364 16,568
2028 -2,544 -1,244 -3,788 12,780
2029 1,739 850 2,589 15,370
2030 -2,326 -910 -3,236 12,134
2031 15,694 4,181 19,874 32,008
2032 -1,455 -1,683 -3,138 28,870
2033 -2,450 -1,422 -3,872 24,998
2034 -2,509 -929 -3,438 21,560
2035 -1,323 270 -1,053 20,507
2036 4,384 1,268 5,652 26,159
2037 6,423 1,066 7,489 33,648
2038 -2,426 -1,308 -3,734 29,914
2039 -2,506 -970 -3,476 26,438
2040 -2,362 -446 -2,808 23,630
2041 -2,409 -203 -2,612 21,018
2042 -2,661 -726 -3,386 17,632
2043 3,627 1,800 5,426 23,058
2044 11,943 2,631 14,574 37,632
2045 -1,985 -1,350 -3,335 34,297
2046 4,001 652 4,653 38,950
2047 -2,116 -1,043 -3,159 35,791
2048 -2,161 -628 -2,789 33,002
2049 6,835 1,839 8,674 41,676
2050 -2,595 -1,508 -4,102 37,573
2051 -2,090 -515 -2,605 34,968
2052 1,655 707 2,363 37,331
2053 -2,730 -1,285 -4,015 33,316
2054 1,742 982 2,725 36,040
2055 -2,465 -858 -3,323 32,717
2056 15,944 4,132 20,077 52,794
2057 -1,556 -1,655 -3,210 49,584
2058 -2,629 -1,469 -4,097 45,487
2059 -2,692 -947 -3,639 41,847
2060 -1,412 375 -1,037 40,810
2061 4,435 1,286 5,722 46,532
2062 6,446 1,062 7,508 54,040
2063 -2,601 -1,345 -3,945 50,094
2064 -2,682 -989 -3,670 46,424
2065 -2,525 -402 -2,927 43,497
2066 -2,575 -195 -2,770 40,727
2067 -2,827 -710 -3,537 37,190
2068 3,628 1,819 5,447 42,637
Average Water Budget over Simulation Period (2019-2068) Average 797 56 853
Total 39,856 2,781 42,637
Average Water Budget over Implementation Period (2022-2041) Average 276 -129 147
Total 5,521 -2,588 2,933
Average Water Budget over Sustainability Period (2042-2068) Average 739 62 801
Total 19,957 1,662 21,619
Average Water Budget over GSP Period (2019-2021)
Average 4,793 1,236 6,028
Total 14,378 3,707 18,085
Simulation
Year
Net Change in Groundwater in Storage
Annual Change in
Groundwater in
Storage
Cumulative
Storage Change
Bedford-Coldwater GSP
Groundwater Model Report TODD GROUNDWATER

FIGURES
November 2021 Figure 1
Location and Topography of
Bedford-Coldwater Basin
Temescal Subbasin
Elsinore Valley Subbasin
Bedford-Coldwater Subbasin
Temescal Subbasin
Legend
0 0.5 1
Scale: Miles
November 2021 Figure 2
Local Watersheds that Drain
into the Bedford-Coldwater
Basin
Temescal
Subbasin
Elsinore Valley Subbasin
Bedford-Coldwater Subbasin
Temescal Subbasin
Legend
0 0.5 1
Scale: Miles
Temescal Wash
Tributary Streams
November 2021 Figure 3
Schematic Plan View
Showing Faulting Associated
with Pull-Apart Basins
Figures Source:

J. E. Wu, K. McClay, P. Whitehouse, T. Dooley, 2012, Regional Geology and Tectonics:

Principles of Geologic Analysis
November 2021 Figure 4
1990 and 2018 Land
Use for Recharge Polygons
November 2021 Figure 5
Average
Annual Rainfall
Temescal
Subbasin
Elsinore Valley Subbasin
Bedford-Coldwater Subbasin
Temescal Subbasin
Legend
0 0.5 1
Scale: Miles
Temescal Wash
Tributary Streams
Watershed Outline
November 2021 Figure 6
Relationship of Rainfall to
Infiltration
0 1
2 3
4 5
6 0 1 2 3 4 5 6
Daily Infiltration (in)
Daily Throughfall (in)
A. Relationship of Infiltration to Throughfall
Sat=0.0 Sat=1.0 Total rain
Infiltration
Runoff
[Throughfall = rainfall - interception]

0.0 0.2

0.4 0.6

0.8 1.0

1.2 0% 20% 40% 60% 80% 100%
Infiltration Adjustment Factor
Soil Saturation (% of porosity)
B. Effect of Soil Saturation on Infiltration
INFFAC=1.0 =0.9 =0.8 =0.7 =0.6
FACsat% = FAC100% + (1 -
November 2021
Figure 7
Rainfall to Runoff Calibration
0 50
100
150
200
250
300
Oct-89 Oct-94 Oct-99 Oct-04 Oct-09 Oct-14 Oct-19
Daily Flow (cubic feet per second)
Coldwater Canyon Creek
Simulated daily Measured
0 20
40 60
80 100
120
140
160
180
200
Oct-89 Oct-94 Oct-99 Oct-04 Oct-09 Oct-14 Oct-19
Outflow (cfs)
Lee Lake Outflow
Simulated daily Measured
November 2021 Figure 8
Location of MODFLOW Model
Domain
MODFLOW Model Domain
Elsinore Valley Subbasin
Bedford-Coldwater Subbasin
Temescal Subbasin
Legend
N
0 0.5 1
Scale: Miles
Temescal Subbasin
November 2021 Figure 9
Location of Management
Areas
0 0.5 1
Scale: Miles
Coldwater Management Area
Bedford Management Area
November 2021 Figure 10
Topographic Elevation of the
Top of Model Layer 1
0 0.51
Scale: Miles
November 2021 Figure 11
Bottom Elevation Distribution
for Model Layer 1
0 0.51
Scale: Miles
November 2021 Figure 12
Bottom Elevation Distribution
for Model Layer 2
0 0.51
Scale: Miles
November 2021 Figure 13
Bottom Elevation Distribution
for Model Layer 3
0 0.51
Scale: Miles
November 2021 Figure 14
Schematic NW-SE Cross
Section to Illustrate Relative
Model Layer Thicknesses
NW SE
Note: Cross Section taken from
MODFLOW model along row 127
Model Layer 3
Model Layer 2
Model Layer 1
Bedford
Canyon
Bedrock Inliers
within Basin
Bedford MA
Midland Area
Temescal
Wash
Elsinore
Valley
Subbasin
Temescal
Subbasin
November 2021
SW NE
Figure 15
Schematic NE-SW Cross
Section to Illustrate Relative
Model Layer Thicknesses
Model Layer 3
Model Layer 2
Model Layer 1
Note: Cross Section taken from
MODFLOW model along column 230
Coldwater
Basin
Bedford MA
Midland Area
Temescal
Wash
Estelle
Mountain
Santa Ana
Mountains
Glen Ivy
Fault
November 2021 Figure 16
Location of Faults Included in
MODFLOW model
Simulated Faults
Mapped Faults
0 0.51
Scale: Miles
November 2021
Figure 17
Location of Streams
Simulated Faults
Mapped Faults
Stream
0 0.5 1
Scale: Miles
Bixby
Creek
Dawson
Creek
Olsen
Canyon
Cajalco
Canyon
November 2021 Figure 18
Distribution of General Head
Boundary Used for Mountain
Front Recharge
Bedrock Inflow Area
Mapped Faults
0 0.51
Scale: Miles
November 2021 Figure 19
Distribution of
Evapotranspiration (ET) Zones
ET Zone 2 – 15 ft extinction depth
ET Zone 1 – 7.5 ft extinction depth
0 0.51
Scale: Miles ET Zone 3
– 3 ft extinction depth
November 2021 Figure 20
Location of Pumping Wells
With Measured Pumping
Rates
0 0.51
Scale: Miles
Well Location with Measured Pumping Volumes
November 2021 Figure 21
Locations of Estimated
Pumping for Historical
Agriculture
0 0.51
Scale: Miles
Location of Estimated Agricultural Pumping
November 2021 Figure 22
Annual Groundwater Pumping
in Bedford-Coldwater Basin
0 2000
4000
6000
8000
10000
12000
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Groundwater Pumping (acre-feet per year)
Measured Groundwater Pumping
November 2021 Figure 23
Location of Primary Quarry
Areas and Wastewater
Facilities
0 0.5 1
Scale: Miles
Coldwater MA
Quarry Operations
TVWD
WRF
Constant Head Boundary
Temescal Wash
Quarry Operations
November 2021 Figure 24
Boundary Conditions Applied
for Recharge Ponds, Quarries
and Subsurface Flow
0 0.5 1
Scale: Miles
Coldwater MA
Quarry Operations
Temescal Wash
Quarry Operations
Constant Head Boundary
WRF Recharge Pond as Well Package
Quarry Pond as River Package
Quarry surface as Drain Package
Quarry Pond as Combined Well and Drain Package

TVWD WRF
Recharge Ponds
November 2021 Figure 25
Distribution of
Aquifer Property Zones
for Layers 1, 2 and 3
9 8
3 4
2 7
6 1
5 Note: Map Zone numbers relate
to Aquifer Property Values on
Table 3 in Report
0 0.5 1
Scale: Miles
November 2021 Figure 26
Initial Groundwater Conditions
for Layer 2
0 0.51
Scale: Miles
November 2021 Figure 27
Location of Monitoring Wells
Used for Model Calibration in
Bedford MA
0 0.51
Scale: Miles
November 2021 Figure 28
Location of Monitoring Wells
Used for Model Calibration in
Coldwater MA
0 0.51
Scale: Miles
November 2021 Figure 29
Scatter Plot Comparing
Simulated to Measured
Groundwater Levels
400
500
600
700
800
900
1000
1100
1200
400 500 600 700 800 900 1000 1100 1200
Simulated Groundwater Eleva�on
Measured Groundwater Eleva�on
Calibra�on Comparison of Measured to Simulated Groundwater Eleva�ons November 2021 Figure 30
Calibration Hydrographs
Bedford MA
North Temescal Wash Area
700
750
800
850
900
950
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Flager#02
Observed
Simulated
Alterna�ve
700
750
800
850
900
950
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Flagler#02A
Observed
Simulated
Alterna�ve
700
750
800
850
900
950
Oct-1989
Oct-1992
Oct-1995Oct-1998Oct-2001Oct-2004
Oct-2007Oct-2010
Oct-2013Oct-2016
Oct-2019
GW Eleva�on (� msl)
Flagler#03A
Observed
Simulated
Alterna�ve
700
750
800
850
900
950
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Flager#03
Observed
Simulated
Alterna�ve
November 2021 Figure 31
Calibration Hydrographs
Bedford MA
North Temescal Wash Area
700
750
800
850
900
950
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Corona#04
Observed
Simulated
Alterna�ve
700
750
800
850
900
950
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Flagler#04
Observed
Simulated
Alterna�ve
700
750
800
850
900
950
Oct-1989
Oct-1992
Oct-1995Oct-1998Oct-2001Oct-2004
Oct-2007Oct-2010
Oct-2013Oct-2016
Oct-2019
GW Eleva�on (� msl)
Non-Potable#02
Observed
Simulated
Alterna�ve
700
750
800
850
900
950
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Non-Potable#01
Observed
Simulated
Alterna�ve
November 2021 Figure 32
Calibration Hydrographs
Bedford MA
Mid Temescal Wash Area
700
750
800
850
900
950
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
TVWD#01A
Observed
Simulated
Alterna�ve
700
750
800
850
900
950
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
TVWD#04
Observed
Simulated
Alterna�ve
700
750
800
850
900
950
Oct-1989
Oct-1992
Oct-1995Oct-1998Oct-2001Oct-2004
Oct-2007Oct-2010
Oct-2013Oct-2016
Oct-2019
GW Eleva�on (� msl)
LLWD_#01-Old
Observed
Simulated
Alterna�ve
700
750
800
850
900
950
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
New_Sump
Observed
Simulated
Alterna�ve
November 2021 Figure 33
Calibration Hydrographs
Coldwater MA
Coldwater Quarry Area
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Corona#01
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Corona#02
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989
Oct-1992
Oct-1995Oct-1998Oct-2001Oct-2004
Oct-2007Oct-2010
Oct-2013Oct-2016
Oct-2019
GW Eleva�on (� msl)
Corona#21
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992
Oct-1995Oct-1998Oct-2001Oct-2004
Oct-2007Oct-2010Oct-2013
Oct-2016Oct-2019
GW Eleva�on (� msl)
Corona#03
Observed
Simulated
Alterna�ve
November 2021 Figure 34
Calibration Hydrographs
Coldwater MA
Mayhew Quarry Area
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Mayhew#01
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Mayhew#02
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Sta�on#72
Observed
Simulated
Alterna�ve
November 2021 Figure 35
Calibration Hydrographs
Coldwater MA
Other Quarry Areas
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007 Oct-2010
Oct-2013Oct-2016Oct-2019
GW Eleva�on (� msl)
Corona#20
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Sta�on#71
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992
Oct-1995
Oct-1998Oct-2001
Oct-2004Oct-2007
Oct-2010
Oct-2013
Oct-2016Oct-2019
GW Eleva�on (� msl)
Sta�on#26
Observed
Simulated
Alterna�ve
November 2021 Figure 36
Calibration Hydrographs
Coldwater MA
North of Quarry Area
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Div_Box_Well
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Trilogy
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
B_Well
Observed
Simulated
Alterna�ve
600
700
800
900
1000
1100
1200
Oct-1989Oct-1992Oct-1995Oct-1998Oct-2001Oct-2004Oct-2007Oct-2010Oct-2013Oct-2016Oct-2019 GW Eleva�on (� msl)
Sta�on#22
Observed
Simulated
Alterna�ve
November 2021 Figure 37
Layer 1 Groundwater Elevations
End of Simulation
September 2018
Inferred Groundwater Flow Direction
900 Simulated Groundwater Elevation
0 0.51
Scale: Miles
November 2021 Figure 38
Layer 1 Groundwater Elevations
Near Highest Levels
March 1995
Inferred Groundwater Flow Direction
900 Simulated Groundwater Elevation
0 0.51
Scale: Miles
November 2021 Figure 39
Layer 1 Groundwater Elevations
Near Lowest Levels
October 2010
Inferred Groundwater Flow Direction
900 Simulated Groundwater Elevation
0 0.51
Scale: Miles
November 2021 Figure 40
Simulated Change in
Groundwater in Storage for
Historical Simulation
-70,000
-60,000
-50,000
-40,000
-30,000
-20,000
-10,000
0 10,000
1990 1995 2000 2005 2010 2015
Cumula�ve Change in Groundwater in Storage (acre-feet)
Water Year
Comparsion of Change in Groundwater in Storage for Historical Period Bedford MA
Coldwater MA
Basin
November 2021 Figure 41
Simulated Groundwater
Storage Change for Future
Baseline Scenario
0 10,000
20,000
30,000
40,000
50,000
60,000
2018 2023 2028 2033 2038 2043 2048 2053 2058 2063 2068
Cumula�ve Change in Groundwater in Storage (acre-feet)
Water Year
Comparsion of Change in Groundwater in Storage for Future Baseline Scenario Bedford MA
Coldwater MA
Basin
November 2021 Figure 42
Layer 1 Groundwater Elevations
Future Baseline Scenario
September 2068
Inferred Groundwater Flow Direction
900 Simulated Groundwater Elevation
0 0.51
Scale: Miles
November 2021 Figure 43
2018 Land
Use for Recharge Polygons
for Future Growth Scenario
November 2021 Figure 44
Simulated Groundwater Storage
Change for Growth-Climate
Change Scenario
0 10,000
20,000
30,000
40,000
50,000
60,000
2018 2023 2028 2033 2038 2043 2048 2053 2058 2063 2068
Cumula�ve Change in Groundwater in Storage (acre-feet)
Water Year
Comparsion of Change in Groundwater in Storage for Future Growth Scenario Bedford MA
Coldwater MA
Basin
November 2021 Figure 45
Layer 1 Groundwater Elevations
Future Growth Scenario
September 2068
Inferred Groundwater Flow Direction
900 Simulated Groundwater Elevation
0 0.51
Scale: Miles
Bedford-Coldwater GSP

TODD GROUNDWATER,
H&H Water Resources,
and Stantec

APPENDIX H
Baseline Water Quality Sampling Results
Baseline Water Quality Data - February 2021
Corona Well 21
Mayhew Well
2 New Sump
Corona NonPotable Well 1 Station 71 TVWD Well 4
Flagler 2A
Well
TVWD
TP-1
Coldwater Coldwater Bedford Bedford Bedford Bedford Bedford Bedford 11-chloroeicosafluoro 3oxaundecane-1-sulfonic Acid ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7 4,8-dioxa-3H-perfluorononanoic Acid (ADONA) ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7 9-chlorohexadecafluoro-3-oxanone-1-sulfonic Acid ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7 Arsenic ug/L MCL-CA 10 ug/L <2 <2 <2 <2 <2 <2 2.1 <2.0
Bicarbonate
mg/L as
CaCO3 190 150 270 240 150 280 280 230
Boron ug/L NL 1000 ug/L <100 <100 260 250 <100 320 160 260 Calcium mg/L none 86 66 120 120 74 130 160 120
Carbonate
mg/L as
CaCO3 <5 <5 <5 <5 <5 <5 <5.0 <5.0
Chloride mg/L SMCL 500 mg/L 30 43 180 170 49 180 140 170 Dissolved Oxygen mg/L none 7.9 6.7 1.2 6.1 5.7 5.7 6.4 4.0 E_ coli MPN/100ml <1 <1 <1 <1 <1 <1 <1.0 <1.0
Fluoride mg/L MCL-CA 2 mg/L 0.46 0.29 0.42 0.44 0.26 0.48 0.21 0.51 Heterotrophic Plate Count CFU/mL 6 17 1 25 1900 6.0 14
Hexafluoropropylene oxide dimer acid (HFPO-DA) ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7 Hydroxide
mg/L as
CaCO3 <5 <5 <5 <5 <5 <5 <5.0 <5.0
Iron ug/L SMCL 300 ug/L 140 <100 <100 <100 <100 <100 <100 <100 Magnesium mg/L none 16 15 30 32 18 30 50 35
Manganese ug/L SMCL 50 ug/L 20 <20 <20 <20 24 38 <20 <20 N-EtFOSAA ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7
Nitrate as N mg/L MCL-CA 10 mg/L 1.9 2.5 0.82 2.6 2.1 1.3 7.4 2.0 N-MeFOSAA ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7
Perfluorobutanesulfonic Acid (PFBS) ng/L NL 500 ng/L 0.81 2.2 26 27 2.4 29 15 27 Perfluorodecanoic Acid (PFDA) ng/L 0.19 <1.7 0.72 0.21 0.32 3.2 <1.7 0.36 Perfluorododecanoic Acid (PFDoDA) ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7 Perfluoroheptanoic Acid (PFHpA) ng/L 0.19 1 1.5 3.3 2.9 4.2 4.4 2.2 Perfluorohexanesulfonic Acid (PFHxS) ng/L <1.7 1.8 7.2 5 2.8 9.8 3.3 8.9 Perfluorohexanoic Acid (PFHxA) ng/L 0.89 2.5 4.1 8.3 5.6 9.3 10 4.1 Perfluorononanoic Acid (PFNA) ng/L <1.7 0.21 3.8 2.3 0.87 2.3 0.65 1.2 Perfluorooctanesulfonic Acid (PFOS) ng/L RL 40 ng/L <1.7 0.91 11 11 4.1 14 4.0 11 Perfluorooctanoic Acid (PFOA) ng/L RL 10 ng/L 0.34 2.9 11 14 7.8 25 11 18 Perfluorotetradecanoic Acid (PFTeDA) ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7 Perfluorotridecanoic Acid (PFTrDA) ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7 Perfluoroundecanoic Acid (PFUnA) ng/L <1.7 <1.7 <1.7 <1.7 <1.7 <1.8 <1.7 <1.7 pH (at Site, grab) pH Units 7.4 7.2 6.8 7 7.3 7.3 7.1 7.0 Potassium mg/L none 1.6 1.8 3.8 3.3 1.8 3.3 3.7 6.1
Sodium mg/L US-HAL 200 mg/L 38 48 140 120 43 140 83 150 Specific Conductance umhos/cm SMCL
1600 UMHOS/C
M 710 570 1200 1400 610 1300 1300 1300
Sulfate mg/L SMCL 500 mg/L 120 110 190 230 120 200 270 270 Temperature (at Site, grab) °C 20 17 23 18 19 22 19 22
Total Alkalinity
mg/L as
CaCO3 none 190 150 270 240 150 280 280 230
Total Coliform MPN/100ml <1 <1 46 <1 <1 <1 <1.0 <1.0
Total Dissolved Solids mg/L SMCL 1000 mg/L 440 410 820 910 430 850 930 900 Total Organic Carbon mg/L <0.3 0.31 1.6 0.59 0.61 1.2 0.30 1.0 Turbidity-at site NTU 1.8 0.28 0.34 1.2 0.25 0.75 0.57 0.52 Notes:1
: Limits on constituent concentrations in water come from multiple sources, as indicated below (https://oehha.ca.gov/water/notification-levels-chemicals-drinking-water):

NL: California drinking water Notification Levels
SMCL: California Secondary Maximum Contiment Level,
AL: Agricultural Limit
MCL: California Secondary Maximum Contiment Level
US-HAL: Federal Health Advisory Limit
RL: California Response Level
Limit
Concentration1 Type of Limit1 WELL NAME Units
Bedford-Coldwater GSP

TODD GROUNDWATER,
H&H Water Resources,
and Stantec

APPENDIX I
Management Areas Designated in the Bedford
Coldwater Subbasin to be Included in the
Groundwater Sustainability Plan

INTRODUCTION
This memorandum summarizes the Management Areas (MAs) designated in the Bedford Coldwater Subbasin (Subbasin) to be included in the Groundwater Sustainability Plan (GSP) developed for the Bedford Coldwater Groundwater Sustainability Agency (BCGSA). As defined in the GSP Regulations, the purpose of MAs is to facilitate implementation of the GSP. The objective of this memorandum is to summarize the rational for creating each MA within the Bedford Coldwater Subbasin.

Management Areas will be described in Section 5 of the GSP, along with sustainability goals, characterization of undesirable results, and minimum thresholds and measurable objectives for each sustainability indicator. These indicators will be described for each MA. Consistent with the GSP Regulations, MAs will be presented in terms of:
• Reason for creation of each MA
• Descriptions, maps, and other information required by GSP Regulations to describe conditions in each MA
• Level of monitoring and analysis appropriate for each MA • Explanation of how management of MAs will not cause undesirable results outside the MA The purpose of dividing a basin into Management Areas is to facilitate implementation of the GSP in instances where a basin has distinctly different areas with unique management needs. As defined in the GSP Regulations, a MA is an area within a basin for which the GSP may identify different minimum thresholds, measurable objectives, monitoring, or projects and management actions based on differences in water use sector, water source type, geology, aquifer characteristics, or other factors. Although a MA may have different minimum thresholds and be operated according to different measurable objectives than the basin as a whole, undesirable results must still be defined consistently throughout the Subbasin.

The operation of each MA must also be managed in a way so as not to cause undesirable results outside of that MA.

The Bedford Coldwater Subbasin is a subbasin of the Elsinore Basin and covers approximately 11 square miles in western Riverside County. The Subbasin covers a portion of the Santa Ana River watershed. The main tributaries to the Santa Ana River include Temescal Creek, which flows through the Subbasin from the southeast to the northwest, and the Bedford Wash, which flows to the northeast along the northern boundary of the Subbasin. The Subbasin is located within the Elsinore-Temecula trough, a low-lying structural block between the Santa Ana Mountains to the west and the Perris Plain on the east. The Subbasin is separated from the Temescal Subbasin to the northwest by a groundwater divide near Bedford Wash. A jurisdictional boundary separates the Subbasin with the Elsinore Valley Subbasin to the south. The Subbasin is thin in some areas, which impedes groundwater flow especially at the northern and southern boundaries.

The Glen Ivy fault separates the Bedford area from the Coldwater area, resulting in differing geology, water use, water quality, and sources of water between the two areas. These differences serve as the basis for defining two management areas in the Subbasin for the purpose of facilitating implementation of the GSP.

The Bedford Coldwater Subbasin is divided into two MAs, Bedford and Coldwater, as defined in the following sections. The MAs will be used in the water budget analysis (presented in Section 5 of the GSP) and in numerical modeling. The MAs will be used to help define the sustainability criteria (undesirable results, minimum thresholds, management objectives) described in Section 6.

DEFINITION OF BEDFORD MANAGEMENT AREA
The Bedford MA is the area east of the Glen Ivy fault to the Estelle Mountain, as shown in Figure 1. The fault offsets the aquifer units in the Bedford MA from the units in the Coldwater MA by up to approximately 250 feet (Todd, 2019), with the west side of the fault (Coldwater MA) down dropped relative to the east side of the fault (Bedford MA). Alluvial sediments are up to 500 feet thick in the Bedford MA, and up to 800 feet deep in the Coldwater MA (Todd and AKM, 2008). Land uses are primarily urban residential and commercial/industrial in the Bedford MA. The only groundwater pumpers in the Bedford MA are the three member agencies of the BCGSA.

The 2017 Upper Temescal Valley Salt and Nutrient Management Plan (SNMP) separates the Bedford area from the Coldwater area and combines it with the Upper Temescal Valley groundwater management zone (GMZ; WEI, 2017).

DEFINITION OF COLDWATER MANAGEMENT AREA
The Coldwater MA is the area located within a down-dropped block between the Glen Ivy fault and the Santa Ana Mountains. Alluvial sediments are more than 800 feet thick in the Coldwater MA (Todd and AKM, 2008). In addition to a greater depth to bedrock, a factor distinguishing the Coldwater MA from the Bedford MA is that most of the groundwater pumping in the Subbasin occurs within this area. The City of Corona and Elsinore Valley Municipal Water District established a production agreement in 2008 to ensure the sustainable use of groundwater in the Coldwater area (EVMWD, 2008). Glen Ivy Hot Springs also has one well in the area that serves an estimated 750 people.

The Coldwater area is a separate groundwater management zone in the 2017 Upper Temescal Valley SNMP due to its distinct geologic structure and deep aquifer units (WEI, 2014).

REFERENCES
Corona and Elsinore Valley Municipal Water District (EVMWD), 2008. Agreement Concerning Water Production from Coldwater. December.

Todd Groundwater (Todd), 2019. Bedford-Coldwater Basin Existing Data Transmittal. February 9.

Todd Engineers and AKM Consulting Engineers (Todd and AKM), 2008. AB3030 Groundwater Management Plan. Prepared for the City of Corona. June.

Wildermuth Environmental, Inc. (WEI), 2014. Rationale for Creating the Upper Temescal Valley Groundwater Management Zone. Letter to EVMWD and Eastern Municipal Water District.

September 8.

WEI, 2017. Salt and Nutrient Management Plan for the Upper Temescal Valley. Final September.

Path: T:\Projects\Bedford Coldwater GSP 80802\GIS\Maps\Figures\GSP Figures\Stantec Management Areas Memo\Figure 1 Management Areas.mxd !"a$
!"a$
Temescal Canyon Road
Cajalco Road
Temescal Canyon Road
Trilogy Parkway
Temescal Canyon Road
!"a$
Glen Ivy Fault (Elsinore Fault Zone)
Glen Ivy Fault (Elsinore Fault Zone)
Elsinore Fault Zone
Figure 1
Management Areas
(
N
0 1,750 3,500
Scale in Feet
Fault Location, dashed where uncertain
Bedford Management Area
Coldwater Management Area
Bedford-Coldwater Basin
Bedford-Coldwater GSP

TODD GROUNDWATER,
H&H Water Resources,
and Stantec

APPENDIX J
Detailed Annual Surface and Groundwater
Budgets
Bedford-Coldwater Basin Surface Water Budget, Model Calibration Period (1990 to 2018) BEDFORD MANAGEMENT AREA (acre-feet per year) COLDWATER MANAGEMENT AREA (acre-feet per year) Outflow from
Elsinore Subbasin
to Bedford MA
Inflow from
Coldwater MA

TVWD WRF
Discharge into
Wash
City of Corona
WRF3 Discharge to
Wash
Tributary and
Local Runoff
Stream
Percolation to
Groundwater
Seepage from
Groundwater to
Streams
Surface Outflow to
Temescal Basin
Tributary and
Local Runoff
Stream
Percolation to
Groundwater
Inflow from
Groundwater to
Streams
Outflow to
Bedford MA
1990 24,043 308 0 0 260 863 731 24,479 284 331 355 308
1991 5,398 2,308 7 0 4,043 2,248 559 10,066 6,175 4,055 188 2,308 1992 3,142 495 48 0 1,524 1,344 409 4,274 3,526 3,141 111 495 1993 63,144 8,156 134 0 24,997 3,920 1,495 94,005 24,042 15,979 93 8,156 1994 6,915 138 273 0 446 1,042 950 7,680 401 324 61 138 1995 8,510 2,462 402 0 7,184 2,422 1,080 17,215 9,416 6,998 43 2,462 1996 2,565 108 406 0 343 494 563 3,491 157 68 19 108
1997 1,392 132 414 0 435 206 233 2,401 270 139 1 132
1998 13,755 4,252 534 0 14,078 3,159 832 30,293 15,077 10,831 5 4,252 1999 4,682 87 840 0 503 341 413 6,184 88 1 0 87
2000 695 93 1,034 0 657 146 117 2,450 474 381 0 93
2001 3,940 668 690 0 2,890 1,731 193 6,651 4,063 3,396 2 668 2002 1,671 95 709 0 435 72 94 2,933 96 1 0 95
2003 6,056 2,067 844 0 3,968 1,655 152 11,433 5,597 3,532 2 2,067 2004 2,928 122 893 0 769 153 83 4,642 285 163 0 122
2005 49,649 13,308 1,029 0 32,278 4,947 2,377 93,695 32,138 18,840 10 13,308 2006 24,731 329 1,068 19 1,512 2,135 2,170 27,693 2,059 1,735 4 329 2007 12,768 22 1,335 50 480 1,031 1,114 14,737 35 14 0 22 2008 8,843 27 1,317 80 370 682 666 10,621 40 13 0 27
2009 6,339 164 1,455 111 947 1,205 637 8,447 1,539 1,377 2 164 2010 14,242 4,676 1,424 172 9,419 2,888 949 27,995 10,297 5,625 4 4,676 2011 23,939 6,872 1,397 194 12,566 3,069 1,580 43,480 14,107 7,239 4 6,872 2012 2,989 163 1,405 109 322 1,172 1,187 5,003 164 1 0 163 2013 1,873 87 0 205 -18 931 831 2,048 88 1 0 87
2014 0 140 0 150 159 664 568 352 267 127 0 140
2015 0 182 0 130 344 577 450 529 362 180 0 182
2016 0 111 0 137 159 403 257 261 273 162 0 111
2017 10,667 4,552 0 148 7,583 2,847 660 20,763 10,608 6,058 2 4,552 2018 2,082 95 0 162 205 727 433 2,250 299 205 0 95
Water
Year
T:\Projects\Bedford Coldwater GSP 80802\Deliverables\GSP\0 Complete GSP\Appendices\Appendix J - Detailed Water Budgets\Appendix J Bedford-Coldwater Detailed Water Budget Tables 20210525.xlsx Surface Water Balance Todd Groundwater Des by: GY
Bedford Management Area Detailed Annual Water Budget, Model Calibration Period (1990 to 2018) Water Year and Type1
1990
D
1991
AN
1992
AN
1993
W
1994
BN
1995
W
1996
D
1997
D
1998
W
1999
D
2000
D
2001
N
2002
D
2003
AN
2004
W
2005
W
2006
BN
2007
D
2008
D
2009
BN
2010
AN
2011
W
2012
BN
2013
D
2014
D
2015
BN
2016
D
2017
W
2018
D
Inflows (AFY)
Subsurface inflow 1,493 1,514 1,054 423 637 427 563 849 354 342 499 556 977 654 562 124 87 143 313 148 80 75 94 165 399 192 92 80 72 Percolation from streams 863 2,248 1,344 3,920 1,042 2,422 494 206 3,159 341 146 1,731 72 1,655 153 4,947 2,135 1,031 682 1,205 2,888 3,069 1,172 931 664 577 403 2,847 727 Bedrock inflow 980 981 979 977 978 1,185 1,194 1,046 897 833 629 592 693 547 393 848 1,119 1,080 1,019 969 706 765 894 897 894 686 297 341 382 Dispersed recharge: non-irrigated land 46 126 102 2,629 63 894 82 123 1,800 127 156 381 13 579 165 4,227 424 -23 17 395 1,621 2,154 249 135 198 332 166 1,581 51 Dispersed recharge: irrigated land 556 1,050 801 2,072 477 1,082 459 493 1,296 390 504 773 340 691 400 1,961 654 282 227 473 736 905 365 305 390 438 387 742 347 Pipe leaks 91 94 96 100 104 110 114 117 124 130 125 120 122 131 142 149 154 153 153 155 154 150 155 164 174 184 191 198 187 Reclaimed water percolation 0 0 0 0 0 20 40 62 107 210 309 373 473 691 891 1,029 854 801 525 291 285 0 487 1,575 1,646 1,462 386 3,438 2,862 Quarry recharge 74 7 18 418 314 121 111 11 36 1 14 85 56 29 37 1 38 0 0 72 14 30 18 22 25 178 252 404 353 Total Inflow 4,103 6,020 4,395 10,538 3,614 6,260 3,057 2,907 7,772 2,375 2,381 4,611 2,746 4,978 2,743 13,287 5,466 3,466 2,936 3,707 6,483 7,148 3,434 4,194 4,390 4,049 2,174 9,631 4,980 Outflows (AFY)
Subsurface outflow -57 -59 -46 -370 -117 -105 -48 -33 -287 -117 -33 -30 -24 -41 -20 -553 -743 -166 -20 -150 -457 -762 -270 11 46 -171 -207 -463 -357 Wells - M&I and domestic -2,570 -2,935 -2,251 -2,252 -1,874 -1,486 -1,896 -1,662 -373 -1,055 -1,336 -1,400 -1,824 -833 -1,046 -188 -306 -995 -1,149 -643 -390 -59 -779 -1,079 -1,346 -947 -966 -1,876 -2,173 Wells - agricultural -1,739 -1,121 -965 -978 -1,065 -863 -658 -945 -1,089 -806 -750 -640 -388 -808 -394 -714 -648 -172 13 -152 -279 -176 147 47 38 -255 -225 251 729 Groundwater discharge to streams -731 -559 -409 -1,495 -950 -1,080 -563 -233 -832 -413 -117 -193 -94 -152 -83 -2,377 -2,170 -1,114 -666 -637 -949 -1,580 -1,187 -831 -568 -450 -257 -660 -433 Riparian evapotranspiration -394 -369 -306 -768 -531 -609 -427 -267 -545 -369 -195 -294 -268 -341 -311 -1,037 -773 -497 -350 -418 -626 -919 -759 -625 -564 -429 -292 -585 -359 Quarry outflow -973 -1,153 -1,012 -1,214 -1,006 -1,297 -1,252 -1,112 -1,471 -1,558 -1,373 -1,108 -1,145 -1,447 -1,490 -2,279 -1,982 -1,972 -1,542 -1,290 -1,654 -1,583 -1,689 -2,455 -2,438 -2,241 -1,232 -3,736 -3,062 Total Outflow -6,464 -6,196 -4,988 -7,076 -5,544 -5,441 -4,845 -4,252 -4,597 -4,318 -3,804 -3,664 -3,743 -3,622 -3,344 -7,149 -6,622 -4,917 -3,714 -3,291 -4,355 -5,080 -4,537 -4,932 -4,831 -4,493 -3,178 -7,069 -5,655 Storage Change (AFY)
Total Inflows minus Total Outflows -2,361 -176 -593 3,462 -1,930 819 -1,787 -1,345 3,174 -1,944 -1,423 947 -998 1,356 -601 6,138 -1,157 -1,451 -778 416 2,128 2,069 -1,103 -738 -440 -444 -1,005 2,562 -675 Notes:
1 : Water year types are described in Section 5 - Water Budget, and shown on Figure 5-1. Water year types are summarized above as follows D = Dry, Below Normal = BN, N = Normal, AN = Above Normal, W = Wet.

T:\Projects\Bedford Coldwater GSP 80802\Deliverables\GSP\0 Complete GSP\Appendices\Appendix J - Detailed Water Budgets\Appendix J Bedford-Coldwater Detailed Water Budget Tables 20210525.xlsx Calibration Budgets from Model Todd Groundwater Des by: GY
Coldwater Management Area Detailed Annual Water Budget, Model Calibration Period (1990 to 2018) Water Year and Type1
1990
D
1991
AN
1992
AN
1993
W
1994
BN
1995
W
1996
D
1997
D
1998
W
1999
D
2000
D
2001
N
2002
D
2003
AN
2004
W
2005
W
2006
BN
2007
D
2008
D
2009
BN
2010
AN
2011
W
2012
BN
2013
D
2014
D
2015
BN
2016
D
2017
W
2018
D
Inflows (AFY)
Subsurface inflow 0 0 0 0 0 0 0 0 0 0 0 0 0 0 10 77 40 18 24 51 83 106 85 85 95 107 117 136 123 Percolation from streams 331 4,055 3,141 15,979 324 6,998 68 139 10,831 1 381 3,396 1 3,532 163 18,840 1,735 14 13 1,377 5,625 7,239 1 1 127 180 162 6,058 205 Bedrock inflow 676 678 675 665 667 788 818 675 570 522 419 397 468 410 338 542 736 725 661 619 508 476 558 562 536 408 166 165 277 Dispersed recharge: non-irrigated land 10 30 59 978 -8 376 -34 -38 723 -14 32 265 -5 325 72 1,976 260 0 10 297 805 1,022 78 43 95 121 78 785 52 Dispersed recharge: irrigated land 305 635 496 1,202 303 685 298 291 766 209 309 402 226 520 228 1,105 339 147 134 283 446 535 201 161 207 249 213 436 193 Pipe leaks 19 20 21 22 22 21 21 21 22 23 29 35 37 40 40 41 42 42 41 40 39 38 39 41 44 46 48 50 47 Quarry runoff recharge 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total Inflow 1,341 5,418 4,393 18,845 1,308 8,868 1,171 1,088 12,912 740 1,169 4,494 728 4,826 850 22,582 3,152 945 883 2,667 7,506 9,416 961 892 1,104 1,111 784 7,631 896 Outflows (AFY)
Subsurface outflow -320 -296 -277 -217 -238 -182 -179 -164 -101 -100 -84 -59 -49 -9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Wells - M&I and domestic -4,148 -4,447 -5,368 -8,150 -6,285 -7,887 -6,968 -6,289 -8,104 -8,344 -5,711 -4,012 -3,911 -3,744 -3,634 -4,110 -5,089 -4,791 -4,520 -4,179 -4,122 -2,391 -2,372 -2,989 -3,927 -3,113 -2,961 -2,078 -973 Wells - agricultural -2,164 -1,627 -995 -343 -2,166 -721 -2,088 -1,996 -811 -1,312 -1,746 -1,300 -680 -329 -239 -62 65 -211 -172 -182 -128 -536 -120 40 144 -245 -92 -343 -395 Groundwater discharge to streams -355 -188 -111 -93 -61 -43 -19 -1 -5 0 0 -2 0 -2 0 -10 -4 0 0 -2 -4 -4 0 0 0 0 0 -2 0 Riparian evapotranspiration -52 -76 -37 -323 -6 -77 -2 -1 -129 0 -306 -427 -472 -531 -496 -617 -204 -685 -463 -450 -601 -337 0 0 0 -387 -14 -503 -557 Quarry operations -4,303 -861 0 0 0 0 0 0 0 0 -1,010 -1,605 -1,606 -977 -3,824 -57 -7 0 -1,983 -2,869 -2,089 -292 0 0 0 0 0 0 0 Total Outflow -11,342 -7,495 -6,787 -9,126 -8,756 -8,909 -9,255 -8,451 -9,151 -9,756 -8,857 -7,404 -6,718 -5,592 -8,193 -4,857 -5,238 -5,687 -7,139 -7,681 -6,943 -3,560 -2,492 -2,950 -3,783 -3,745 -3,067 -2,926 -1,924 Storage Change (AFY)
Total Inflows minus Total Outflows -10,000 -2,077 -2,395 9,719 -7,448 -42 -8,084 -7,363 3,761 -9,017 -7,688 -2,909 -5,990 -766 -7,344 17,724 -2,087 -4,741 -6,256 -5,015 562 5,856 -1,531 -2,058 -2,679 -2,633 -2,282 4,705 -1,028 Notes:
1 : Water year types are described in Section 5 - Water Budget, and shown on Figure 5-1. Water year types are summarized above as follows D = Dry, Below Normal = BN, N = Normal, AN = Above Normal, W = Wet.

T:\Projects\Bedford Coldwater GSP 80802\Deliverables\GSP\0 Complete GSP\Appendices\Appendix J - Detailed Water Budgets\Appendix J Bedford-Coldwater Detailed Water Budget Tables 20210525.xlsx Calibration Budgets from Model Todd Groundwater Des by: GY
Bedford Management Area Detailed Annual Water Budget, Baseline Period Water Year
2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 Inflows
Subsurface inflow 71 88 83 91 91 77 91 90 84 92 84 88 63 83 91 91 84 80 79 91 91 92 92 92 80 71 87 83 95 103 77 102 111 98 120 100 110 65 103 149 160 139 113 103 154 171 173 166 161 121 Percolation from streams 3,730 1,440 2,389 1,070 887 2,923 1,004 798 2,282 652 1,843 624 4,284 1,682 1,082 934 1,276 2,744 2,732 1,013 780 594 494 397 2,556 3,528 1,486 2,433 1,256 1,053 3,052 1,088 992 2,460 713 2,082 781 4,461 1,783 1,141 981 1,531 2,849 2,844 1,078 837 666 592 473 2,704 Bedrock inflow 1008 1008 1007 1010 1012 905 846 653 613 668 518 377 788 1015 973 918 877 628 699 819 823 819 624 270 313 720 981 1168 1281 1131 918 855 663 623 681 528 384 802 1031 985 931 884 628 699 833 837 835 636 274 318 Dispersed recharge: non-irrigated land 3,642 330 1,510 205 280 2,393 218 300 811 46 957 199 4,625 534 -6 23 418 1,529 2,081 289 160 228 378 193 1,524 3,601 330 1,510 205 291 2,507 232 333 844 51 1,018 226 4,753 563 0 27 444 1,623 2,147 302 166 241 389 202 1,584 Dispersed recharge: irrigated land 1,137 424 757 372 433 897 334 424 572 262 692 374 1,507 521 260 245 500 762 897 362 303 387 437 383 735 1,133 423 757 372 434 895 334 424 572 261 692 374 1,507 520 260 245 502 760 897 362 304 387 437 383 737 Pipe leaks 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 46 43 29 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 13 Reclaimed water percolation 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,856 1,887 1,897 1,897 1,897 1,887 1,897 1,897 1,897 1,887 1,897 1,897 1,897 1,887 1,897 1,897 1,687 1,887 1,897 1,897 1,897 1,887 Quarry recharge 107 151 128 173 185 118 167 184 159 194 159 194 82 136 183 194 182 133 110 168 189 199 195 205 152 99 150 126 167 182 116 169 184 156 196 158 193 78 137 186 197 178 133 111 175 193 201 195 206 152 Total Inflow 11,597 5,341 7,775 4,823 4,791 9,214 4,562 4,351 6,421 3,816 6,155 3,758 13,251 5,873 4,485 4,308 5,238 7,777 8,499 4,645 4,248 4,220 4,121 3,442 7,263 11,053 5,359 7,978 5,275 5,110 9,477 4,691 4,618 6,655 3,934 6,488 3,979 13,566 6,047 4,631 4,452 5,581 8,018 8,712 4,607 4,409 4,415 4,325 3,609 7,516 Outflows
Subsurface outflow -514 -494 -558 -439 -369 -571 -461 -358 -442 -344 -416 -317 -654 -638 -442 -364 -388 -564 -662 -504 -411 -364 -343 -309 -466 -674 -587 -655 -545 -485 -681 -557 -450 -564 -441 -532 -421 -769 -733 -492 -400 -467 -648 -746 -546 -434 -387 -384 -353 -534 Wells - M&I and domestic -1,310 -1,307 -1,309 -1,305 -1,303 -1,312 -1,305 -1,304 -1,306 -1,303 -1,306 -1,303 -1,313 -1,309 -1,303 -1,302 -1,304 -1,309 -1,310 -1,305 -1,303 -1,303 -1,303 -1,302 -1,307 -1,313 -1,307 -1,309 -1,310 -1,325 -1,333 -1,327 -1,326 -1,328 -1,325 -1,329 -1,325 -1,334 -1,330 -1,325 -1,324 -1,325 -1,330 -1,332 -1,340 -1,324 -1,325 -1,325 -1,324 -1,328 Wells - agricultural 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Groundwater discharge to streams -1,479 -1,284 -1,407 -1,008 -795 -1,351 -957 -632 -806 -580 -614 -429 -1,990 -1,632 -1,051 -865 -773 -1,051 -1,457 -963 -718 -507 -372 -244 -559 -1,690 -1,354 -1,543 -1,221 -965 -1,519 -1,048 -722 -893 -641 -698 -510 -2,202 -1,722 -1,113 -919 -839 -1,151 -1,566 -1,032 -777 -562 -419 -275 -618 Riparian evapotranspiration -1,125 -828 -992 -766 -685 -1,005 -751 -587 -643 -508 -615 -467 -1,455 -1,012 -701 -532 -568 -811 -1,061 -767 -601 -533 -456 -378 -606 -1,233 -859 -1,044 -851 -767 -1,091 -795 -628 -688 -538 -656 -503 -1,546 -1,048 -724 -548 -601 -850 -1,106 -790 -622 -554 -476 -396 -639 Quarry outflow -2,911 -2,546 -2,647 -2,358 -2,220 -2,652 -2,392 -2,225 -2,383 -2,179 -2,293 -2,152 -2,934 -2,667 -2,320 -2,161 -2,183 -2,577 -2,767 -2,400 -2,207 -2,094 -2,065 -2,015 -2,363 -2,855 -2,578 -2,669 -2,427 -2,340 -2,763 -2,481 -2,314 -2,475 -2,257 -2,401 -2,245 -3,030 -2,729 -2,389 -2,233 -2,285 -2,669 -2,854 -2,274 -2,257 -2,165 -2,150 -2,104 -2,464 Total Outflow -7,339 -6,459 -6,913 -5,876 -5,373 -6,891 -5,867 -5,106 -5,580 -4,914 -5,245 -4,668 -8,346 -7,258 -5,817 -5,225 -5,216 -6,312 -7,257 -5,939 -5,240 -4,801 -4,538 -4,247 -5,300 -7,764 -6,685 -7,220 -6,354 -5,882 -7,388 -6,208 -5,440 -5,948 -5,200 -5,617 -5,005 -8,880 -7,562 -6,044 -5,425 -5,517 -6,649 -7,604 -5,981 -5,414 -4,992 -4,755 -4,451 -5,583 Storage change
Inflows - outflows 4,258 -1,118 862 -1,053 -582 2,323 -1,305 -754 841 -1,099 910 -910 4,905 -1,385 -1,332 -917 22 1,465 1,243 -1,294 -991 -581 -417 -805 1,963 3,289 -1,326 758 -1,078 -772 2,090 -1,517 -823 707 -1,267 872 -1,026 4,686 -1,515 -1,413 -973 64 1,369 1,108 -1,375 -1,006 -577 -429 -842 1,933 T:\Projects\Bedford Coldwater GSP 80802\Deliverables\GSP\0 Complete GSP\Appendices\Appendix J - Detailed Water Budgets\Appendix J Bedford-Coldwater Detailed Water Budget Tables 20210525.xlsx Baseline Budgets, Model Todd Groundwater Des by: GY
Coldwater Management Area Detailed Annual Water Budget, Baseline Period Water Year
2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 Inflows
Subsurface inflow 145 108 104 85 82 98 78 72 77 65 76 70 105 62 33 25 35 51 56 24 11 10 16 22 44 65 26 20 0 0 16 0 0 0 0 0 0 28 0 0 0 0 0 0 0 0 0 0 0 0 Percolation from streams 12,463 227 5,176 50 121 7,522 0 323 3,482 0 3,533 137 15,268 549 0 0 756 5,882 7,535 0 0 57 55 79 5,447 12,343 227 5,267 50 130 7,875 0 354 3,649 0 3,689 164 15,626 596 0 0 817 6,062 7,688 0 0 72 64 91 5,587 Bedrock inflow 572 573 571 577 580 530 490 386 366 429 369 301 504 658 638 579 549 428 418 493 499 477 356 134 148 382 558 675 774 669 525 484 380 359 424 363 295 500 657 636 577 545 422 413 490 494 473 351 127 141 Dispersed recharge: non-irrigated land 1,659 560 1,891 414 520 2,833 405 529 1,111 199 1,314 408 5,339 811 148 168 683 1,917 2,522 489 337 447 606 410 1,892 4,139 561 1,891 414 526 2,934 406 550 1,132 192 1,363 423 5,454 827 141 160 698 1,999 2,576 491 331 448 604 407 1,940 Dispersed recharge: irrigated land 617 213 396 183 214 476 168 215 292 129 355 186 814 265 126 121 256 394 476 182 147 189 230 186 388 615 212 396 183 214 477 168 215 293 129 355 186 814 265 126 121 257 393 476 182 147 189 230 186 388 Pipe leaks 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 24 15 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5 Quarry runoff recharge 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total Inflow 15,481 1,707 8,163 1,334 1,540 11,485 1,165 1,550 5,353 848 5,671 1,127 22,054 2,371 970 919 2,303 8,696 11,031 1,215 1,019 1,205 1,287 857 7,943 17,571 1,609 8,274 1,444 1,553 11,833 1,064 1,505 5,439 751 5,776 1,073 22,428 2,350 910 864 2,322 8,881 11,158 1,169 979 1,188 1,255 817 8,062 Outflows
Subsurface outflow 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 -1 0 0 0 -3 -10 0 -9 -20 -13 -27 -14 -20 0 -18 -56 -67 -54 -32 -22 -61 -77 -80 -73 -69 -42 Wells - M&I and domestic -2,975 -2,980 -2,981 -2,981 -2,979 -2,980 -2,980 -2,981 -2,980 -2,981 -2,981 -2,981 -2,981 -2,981 -2,981 -2,981 -2,981 -2,981 -2,981 -2,981 -2,981 -2,980 -2,981 -2,981 -2,981 -2,981 -2,981 -2,981 -2,991 -3,027 -3,032 -3,032 -3,032 -3,027 -3,032 -3,032 -3,032 -3,026 -3,032 -3,032 -3,032 -3,027 -3,032 -3,032 -3,032 -3,027 -3,032 -3,032 -3,032 -3,027 Wells - agricultural -34 -43 -29 -48 -47 -34 -48 -42 -34 -51 -29 -45 -23 -34 -48 -39 -40 -34 -28 -40 -51 -48 -47 -46 -40 -34 -43 -29 -48 -47 -34 -48 -42 -34 -51 -29 -45 -23 -34 -48 -39 -40 -34 -28 -40 -51 -48 -47 -46 -40 Groundwater discharge to streams -7 0 -3 0 0 -6 0 0 -1 0 -1 0 -11 -2 0 0 0 -3 -3 0 0 0 0 0 -1 -7 0 -3 0 0 -6 0 0 -1 0 -1 0 -11 -2 0 0 0 -3 -3 0 0 0 0 0 -2 Riparian evapotranspiration -153 -146 -151 -157 -165 -153 -155 -151 -139 -147 -149 -151 -164 -140 -145 -133 -141 -155 -145 -155 -154 -165 -158 -165 -168 -163 -146 -151 -158 -169 -155 -158 -154 -142 -149 -152 -154 -167 -142 -148 -135 -144 -157 -148 -158 -157 -167 -161 -168 -170 Quarry operations 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total Outflow -3,169 -3,169 -3,162 -3,185 -3,192 -3,174 -3,183 -3,173 -3,155 -3,179 -3,159 -3,177 -3,178 -3,156 -3,174 -3,152 -3,162 -3,173 -3,157 -3,176 -3,185 -3,193 -3,186 -3,193 -3,190 -3,184 -3,169 -3,164 -3,200 -3,253 -3,227 -3,246 -3,246 -3,217 -3,259 -3,227 -3,251 -3,228 -3,228 -3,283 -3,272 -3,265 -3,258 -3,234 -3,290 -3,312 -3,327 -3,313 -3,316 -3,280 Storage change
Inflows - outflows 12,312 -1,462 5,000 -1,852 -1,652 8,311 -2,018 -1,623 2,198 -2,331 2,512 -2,050 18,876 -786 -2,203 -2,233 -859 5,523 7,874 -1,961 -2,166 -1,989 -1,898 -2,335 4,753 14,387 -1,560 5,110 -1,757 -1,701 8,606 -2,182 -1,741 2,222 -2,508 2,549 -2,178 19,200 -878 -2,373 -2,408 -943 5,623 7,925 -2,122 -2,333 -2,139 -2,058 -2,499 4,781 T:\Projects\Bedford Coldwater GSP 80802\Deliverables\GSP\0 Complete GSP\Appendices\Appendix J - Detailed Water Budgets\Appendix J Bedford-Coldwater Detailed Water Budget Tables 20210525.xlsx Baseline Budgets, Model Todd Groundwater Des by: GY
Bedford Management Area Detailed Annual Water Budget, Growth And Climate Change 50-year Period Water Year
2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 Inflows
Subsurface inflow 71 88 83 91 91 77 91 90 84 92 84 88 63 83 91 91 84 80 79 91 91 92 92 93 80 71 87 83 91 93 77 93 92 85 98 85 90 65 85 130 142 112 86 81 131 149 149 138 129 88 Percolation from streams 3,665 1,462 2,266 1,210 1,052 2,841 1,111 1,036 2,180 824 1,824 863 4,146 1,641 1,097 950 1,486 2,586 2,612 1,153 912 760 744 565 2,399 3,300 1,540 2,299 1,350 1,250 3,023 1,175 1,253 2,343 877 2,078 1,046 4,413 1,838 1,154 989 1,722 2,727 2,762 1,199 954 847 869 705 2,579 Bedrock inflow 1082 1081 1080 1083 1085 965 885 712 696 764 605 469 822 1005 943 903 868 686 751 861 871 870 692 359 402 790 1046 1219 1319 1185 981 903 722 700 772 615 478 832 1022 962 919 882 681 746 874 878 880 698 360 402 Dispersed recharge: non-irrigated land 3,604 493 1,685 331 416 2,439 282 484 1,064 42 1,150 313 4,474 617 -16 18 592 1,619 2,304 372 175 319 530 269 1,705 3,547 493 1,685 332 437 2,567 302 540 1,116 54 1,238 360 4,609 661 -4 28 639 1,734 2,395 394 187 342 551 287 1,781 Dispersed recharge: irrigated land 1,854 743 1,229 675 751 1,409 596 756 998 495 1,115 686 2,354 814 491 463 869 1,267 1,455 619 545 689 743 706 1,193 1,848 747 1,229 675 753 1,404 596 756 1,001 492 1,115 686 2,355 813 491 463 873 1,261 1,455 619 546 688 743 706 1,195 Pipe leaks 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 113 84 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 50 Reclaimed water percolation 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,139 2,176 2,197 2,197 2,197 2,176 2,197 2,197 2,197 2,176 2,197 2,197 2,197 2,176 2,197 2,197 2,197 2,176 2,197 2,197 2,197 2,176 Quarry recharge 299 456 409 490 510 380 486 512 472 528 475 523 304 432 518 542 513 416 370 488 528 515 529 542 448 330 454 406 486 512 380 495 517 471 540 475 529 294 439 529 554 512 419 372 498 540 553 539 550 451 Total Inflow 12,833 6,581 9,009 6,138 6,163 10,368 5,709 5,848 7,752 5,003 7,511 5,201 14,422 6,851 5,383 5,226 6,670 8,912 9,829 5,843 5,381 5,503 5,588 4,793 8,486 12,145 6,625 9,178 6,507 6,490 10,683 5,815 6,131 7,948 5,086 7,858 5,441 14,800 7,109 5,514 5,347 6,972 9,161 10,064 5,967 5,485 5,712 5,790 4,990 8,722 Outflows
Subsurface outflow -453 -429 -448 -372 -298 -485 -402 -281 -341 -276 -304 -244 -589 -563 -370 -280 -309 -461 -556 -444 -329 -246 -246 -222 -351 -585 -524 -544 -487 -438 -600 -511 -394 -471 -389 -431 -369 -713 -681 -448 -334 -401 -571 -666 -509 -372 -315 -315 -299 -475 Wells - M&I and domestic -1,895 -1,883 -1,884 -1,880 -1,882 -1,888 -1,881 -1,879 -1,881 -1,879 -1,880 -1,882 -1,891 -1,884 -1,879 -1,878 -1,878 -1,883 -1,886 -1,880 -1,878 -1,879 -1,878 -1,878 -1,882 -1,892 -1,883 -1,884 -1,888 -1,910 -1,919 -1,911 -1,910 -1,910 -1,909 -1,911 -1,913 -1,926 -1,915 -1,909 -1,908 -1,906 -1,914 -1,917 -1,911 -1,906 -1,908 -1,908 -1,909 -1,910 Wells - agricultural 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Groundwater discharge to streams -1,730 -1,637 -1,835 -1,396 -1,142 -1,831 -1,316 -997 -1,283 -940 -1,032 -817 -2,581 -2,046 -1,284 -1,049 -1,067 -1,467 -1,973 -1,356 -1,038 -819 -726 -548 -957 -2,266 -1,803 -2,006 -1,640 -1,352 -2,037 -1,413 -1,100 -1,384 -1,004 -1,133 -903 -2,817 -2,166 -1,360 -1,101 -1,150 -1,577 -2,083 -1,422 -1,082 -880 -800 -614 -1,048 Riparian evapotranspiration -1,388 -1,055 -1,315 -972 -895 -1,375 -952 -791 -905 -691 -891 -697 -2,041 -1,289 -828 -626 -730 -1,122 -1,487 -969 -758 -707 -648 -570 -922 -1,763 -1,143 -1,391 -1,059 -987 -1,462 -988 -832 -949 -715 -928 -734 -2,140 -1,338 -850 -640 -765 -1,173 -1,534 -992 -776 -723 -672 -599 -960 Quarry outflow -2,866 -2,504 -2,595 -2,405 -2,321 -2,658 -2,408 -2,322 -2,420 -2,292 -2,358 -2,289 -2,885 -2,590 -2,348 -2,244 -2,301 -2,562 -2,705 -2,415 -2,288 -2,237 -2,213 -2,197 -2,427 -2,831 -2,532 -2,616 -2,440 -2,407 -2,749 -2,481 -2,402 -2,494 -2,353 -2,450 -2,370 -2,969 -2,659 -2,416 -2,311 -2,375 -2,639 -2,795 -2,479 -2,337 -2,288 -2,289 -2,275 -2,508 Total Outflow -8,332 -7,508 -8,078 -7,025 -6,538 -8,238 -6,959 -6,270 -6,830 -6,078 -6,466 -5,929 -9,987 -8,373 -6,709 -6,076 -6,284 -7,496 -8,607 -7,063 -6,292 -5,889 -5,712 -5,416 -6,538 -9,336 -7,884 -8,441 -7,514 -7,093 -8,767 -7,304 -6,637 -7,209 -6,371 -6,854 -6,288 -10,566 -8,759 -6,983 -6,294 -6,597 -7,874 -8,995 -7,312 -6,474 -6,114 -5,985 -5,695 -6,901 Storage change
Inflows - outflows 4,501 -927 932 -888 -375 2,130 -1,250 -422 922 -1,074 1,045 -728 4,435 -1,522 -1,325 -849 385 1,416 1,223 -1,220 -910 -386 -123 -623 1,948 2,808 -1,259 738 -1,007 -603 1,916 -1,489 -506 740 -1,285 1,004 -848 4,234 -1,650 -1,469 -947 375 1,286 1,068 -1,345 -989 -402 -195 -705 1,821 MODFLOW 4,501 -927 932 -888 -375 2,130 -1,250 -422 922 -1,074 1,045 -728 4,435 -1,522 -1,325 -849 385 1,416 1,223 -1,220 -910 -386 -123 -623 1,948 2,808 -1,259 738 -1,007 -603 1,916 -1,489 -506 740 -1,285 1,004 -848 4,234 -1,650 -1,469 -947 375 1,286 1,068 -1,345 -989 -402 -195 -705 1,821 T:\Projects\Bedford Coldwater GSP 80802\Deliverables\GSP\0 Complete GSP\Appendices\Appendix J - Detailed Water Budgets\Appendix J Bedford-Coldwater Detailed Water Budget Tables 20210525.xlsx Growth Budgets, Model Todd Groundwater Des by: GY
Coldwater Management Area Detailed Annual Water Budget, Growth And Climate Change 50-year Period Water Year
2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 Inflows
Subsurface inflow 154 122 123 103 100 120 95 92 102 85 97 91 127 81 48 40 58 74 78 44 30 30 40 49 73 89 45 43 18 12 39 9 4 16 0 11 5 51 2 0 0 0 0 3 0 0 0 0 0 0 Percolation from streams 12,454 227 5,175 49 120 7,516 0 323 3,480 0 3,529 136 15,254 545 0 0 755 5,875 7,530 0 0 57 52 77 5,439 12,334 226 5,265 48 130 7,878 0 361 3,650 0 3,684 168 15,608 605 0 0 823 6,060 7,681 0 0 72 65 94 5,587 Bedrock inflow 550 551 548 554 557 505 459 357 350 421 370 310 491 608 560 497 455 362 380 466 472 454 334 123 134 353 523 637 729 632 499 455 350 343 416 366 305 488 607 559 494 451 357 376 463 468 450 329 116 128 Dispersed recharge: non-irrigated land 1,617 1,003 2,451 804 941 3,294 716 992 1,713 420 1,860 793 5,839 1,170 360 374 1,177 2,413 3,194 819 579 804 1,038 771 2,448 4,637 1,007 2,451 803 951 3,395 712 1,024 1,743 407 1,924 816 5,951 1,189 348 359 1,202 2,502 3,262 816 565 803 1,035 764 2,497 Dispersed recharge: irrigated land 832 304 533 273 297 624 232 319 420 187 475 277 1,060 332 186 178 354 544 636 244 212 274 305 275 521 828 304 533 273 297 623 232 319 421 186 475 277 1,060 332 186 178 356 540 636 244 215 274 305 275 521 Pipe leaks 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 44 26 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 Quarry runoff recharge 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total Inflow 15,655 2,254 8,878 1,830 2,063 12,107 1,550 2,131 6,113 1,161 6,379 1,655 22,819 2,784 1,203 1,137 2,847 9,315 11,867 1,620 1,341 1,667 1,818 1,344 8,664 18,289 2,153 8,977 1,916 2,048 12,442 1,417 2,067 6,181 1,017 6,468 1,579 23,167 2,743 1,101 1,040 2,840 9,467 11,966 1,531 1,256 1,608 1,743 1,258 8,740 Outflows
Subsurface outflow 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 -1 0 0 0 0 0 0 0 0 0 -5 0 0 0 0 -37 -49 -27 -5 0 -38 -56 -56 -45 -38 -8 Wells - M&I and domestic -3,048 -3,049 -3,061 -3,044 -3,044 -3,062 -3,040 -3,050 -3,061 -3,048 -3,056 -3,045 -3,067 -3,054 -3,045 -3,047 -3,056 -3,051 -3,067 -3,044 -3,040 -3,042 -3,049 -3,040 -3,051 -3,057 -3,049 -3,061 -3,055 -3,091 -3,115 -3,093 -3,104 -3,109 -3,101 -3,109 -3,098 -3,115 -3,107 -3,098 -3,100 -3,104 -3,104 -3,120 -3,097 -3,088 -3,096 -3,102 -3,093 -3,099 Wells - agricultural -78 -87 -73 -103 -103 -67 -106 -96 -68 -95 -72 -97 -61 -82 -98 -96 -78 -83 -61 -102 -105 -109 -91 -111 -89 -72 -87 -73 -103 -103 -67 -106 -96 -68 -95 -72 -97 -61 -82 -98 -96 -78 -83 -61 -102 -105 -108 -91 -111 -89 Groundwater discharge to streams -6 0 -2 0 0 -5 0 0 -1 0 -1 0 -10 -2 0 0 0 -3 -3 0 0 0 0 0 -1 -6 0 -2 0 0 -6 0 0 -1 0 -1 0 -10 -2 0 0 0 -3 -3 0 0 0 0 0 -2 Riparian evapotranspiration -166 -161 -165 -170 -181 -168 -172 -165 -151 -162 -164 -165 -179 -153 -159 -144 -154 -170 -160 -170 -169 -180 -172 -180 -183 -177 -160 -166 -171 -184 -170 -175 -167 -154 -164 -167 -168 -183 -155 -162 -147 -157 -172 -163 -173 -172 -182 -176 -184 -186 Quarry operations 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total Outflow -3,298 -3,297 -3,302 -3,317 -3,327 -3,301 -3,318 -3,310 -3,281 -3,304 -3,293 -3,308 -3,317 -3,291 -3,302 -3,287 -3,288 -3,307 -3,291 -3,316 -3,313 -3,331 -3,312 -3,332 -3,325 -3,312 -3,296 -3,303 -3,329 -3,379 -3,357 -3,374 -3,366 -3,332 -3,364 -3,349 -3,364 -3,369 -3,346 -3,395 -3,392 -3,366 -3,368 -3,347 -3,410 -3,421 -3,443 -3,414 -3,426 -3,383 Storage change
Inflows - outflows 12,357 -1,043 5,577 -1,487 -1,264 8,806 -1,768 -1,180 2,831 -2,143 3,086 -1,653 19,502 -507 -2,099 -2,151 -441 6,008 8,575 -1,695 -1,972 -1,664 -1,495 -1,989 5,339 14,978 -1,143 5,675 -1,413 -1,331 9,086 -1,957 -1,299 2,849 -2,347 3,119 -1,784 19,799 -603 -2,294 -2,352 -526 6,100 8,619 -1,879 -2,165 -1,835 -1,671 -2,168 5,357 MODFLOW 12,357 -1,882 3,903 -2,191 -2,092 6,602 -2,416 -1,958 1,646 -2,544 1,739 -2,326 15,694 -1,455 -2,450 -2,509 -1,323 4,384 6,423 -2,426 -2,506 -2,362 -2,409 -2,661 3,627 11,943 -1,985 4,001 -2,116 -2,161 6,835 -2,595 -2,090 1,655 -2,730 1,742 -2,465 15,944 -1,556 -2,629 -2,692 -1,412 4,435 6,446 -2,601 -2,682 -2,525 -2,575 -2,827 3,628 T:\Projects\Bedford Coldwater GSP 80802\Deliverables\GSP\0 Complete GSP\Appendices\Appendix J - Detailed Water Budgets\Appendix J Bedford-Coldwater Detailed Water Budget Tables 20210525.xlsx Growth Budgets, Model Todd Groundwater Des by: GY
Bedford-Coldwater GSP

TODD GROUNDWATER,
H&H Water Resources,
and Stantec

APPENDIX K
Bedford-Coldwater GSP Data Management
System Description
2490 Mariner Square Loop, Suite 215 | Alameda, CA 94501 | 510 747 6920 | toddgroundwater.com May 19, 2021

TECHNICAL MEMORANDUM
To: Victor Harris, H&H Water Resources
From: Maureen Reilly, PE and Chad Taylor, PG, CHG
Re: Data Management System (DMS) Documentation, Bedford-Coldwater Groundwater Sustainability Plan

1. EXECUTIVE SUMMARY
The Bedford Coldwater Groundwater Basin Agency (BCGSA) was formed by the City of Corona (Corona), Elsinore Valley Municipal Water District (EVMWD), and Temescal Valley Water District (TVWD) through a Joint Powers Authority (JPA) to fulfill the role and legal obligations of a Groundwater Sustainable Agency (GSA) for the Bedford-Coldwater Subbasin (Basin) of the Elsinore Valley Groundwater Basin in accordance with the Sustainable Groundwater Management Act (SGMA). Foremost among the responsibilities is to develop, adopt, and implement a Groundwater Sustainability Plan (GSP) for the Basin.

As part of GSP development, the BCGSA has compiled data from various sources that are relevant to groundwater, geology, and water supply the Basin. These data focus on information that have been required and useful for the preparation of the GSP. The purpose of this Technical Memorandum (TM) is to document the Data Management System (DMS) developed as part of the GSP.

Corona, EVMWD, and TVWD have been collecting and compiling groundwater data including water levels, water quality, and water use for the GSP. As part of the GSP, the DMS has been redesigned to be practicable, usable, intuitive, and cost effective. The data (and data from the BCGSA and other sources) are being compiled in an Access database, geographic information system (GIS) geodatabase, and Excel workbooks. This DMS has been prepared to facilitate queries and other means of quickly checking and summarizing data and extracting relevant information for GSP preparation. This memo outlines the type of data available in the DMS and details how the data are stored. More information on available data is documented in the technical memorandum, “Bedford-Coldwater Basin Existing Data Transmittal” (Todd 2019).

2. DMS TYPES AND SOURCES
Data collected and compiled for the GSP have been stored in a variety of formats based on the type of data collected. Spatial information such as ArcGIS files, aerial imagery, and or other map sources, are stored in a Geodatabase. Tabular data are stored in subject-specific Bedford-Coldwater Basin GSP
TM: Data Management System 2 TODD GROUNDWATER
relational databases. Additional datasets are stored in files best suited for analysis. To be specific, climate data are stored in an Excel workbook to allow for cumulative departure calculations, scanned well documents are stored as images to preserve the detail on the hardcopy forms, and online datasets updated by other agencies are included by reference.

Discussed below are the data formats and the type of data available within that format.

3. GEODATABASE
Spatial data are stored in a geodatabase, which allows spatial files to be easily accessed and transferred with all appropriate spatial information. Within the BC Geodatabase, consistent and feature dataset structures have been constructed to group associated data sets and maintain coordinate system assignments.

3.1 Jurisdiction Boundaries
The basin boundaries for the Bedford-Coldwater Basin, management areas, and neighboring basins are available as spatial coverages in the geodatabase. State, local, and federal boundaries within and surrounding the Bedford-Coldwater Basin were compiled from state and federal sources. These boundaries include all water districts and other local agencies near the basin as well as federally owned land. These boundaries are included in the JurisdictionalAreas feature dataset in the project geodatabase.

3.2 Surface Water Body Location and Watershed Mapping
Mapping data for surface water features have been provided from publicly available sources. These mapped data include locations of aqueducts, reservoirs, rivers, streams, drainages, lakes, and ponds. These data are presented in the project geodatabase in feature classes named HydrologyArcs, and HydrologyPolygons. DWR defined watershed coverages are also stored in the ArcHydro geodatabase names Watershed.

3.3 Mapping of Natural Communities Commonly Associated with Groundwater GSP Regulations require identification of Groundwater Dependent Ecosystems (GDEs), which are defined as ecological communities or species that depend on groundwater emerging from aquifers or on groundwater occurring near the ground surface. A statewide database and mapping tool, developed by DWR, provides geographic information on Natural Communities Commonly Associated with Groundwater (NCAAG). While these do not necessarily represent GDEs, the dataset is a starting point in identifying GDEs. The mapping data for watersheds surrounding the Basin are included in the project geodatabase in the Hydrology feature dataset in feature classes named GDE_NCCAGWetlands and GDE_NCCAGVegetation.

3.4 Ground Surface Elevation Data
Ground surface elevation data are available from the USGS in the form of National Elevation Dataset (NED) GIS grid files (rasters) and raster and vector topographic map datasets. Both Bedford-Coldwater Basin GSP
TM: Data Management System 3 TODD GROUNDWATER
datasets have been compiled for the area surrounding and including the Basin. The 10- meter resolution NED data have been combined into a single raster.

3.5 Aerial Photographs
Aerial photographs of the area surrounding the Basin have been downloaded from the USGS National Aerial Imagery Program (NAIP) for 2004, 2005, 2006, 2009, 2010, 2012, 2014, and 2016. Selected historical aerial imagery of the Temescal Wash area from Google Earth and privately held aerial imagery archives have also been acquired. These aerial photographs are rectified GIS raster datasets whenever possible. Rectified GIS datasets are included in the project geodatabase, unrectified aerial imagery is stored separately.

3.6 Soil Maps
Soil information for the Basin and surrounding areas have been downloaded from the Natural Resources Conservation Service (NRCS 2018). Soil data are mapped and maintained by NRCS in a standardized format that is compatible with tools that NRCS makes freely available to the public. The soils data for the area surrounding the basin have been maintained in the standard NRCS formats to facilitate future use. These raw data are available for preparation of a various soil data presentations and analyses. The hydrologic soil group data from these datasets have been also mapped using the NRCS Soil Data Development Toolbox. These data are in the Soils feature dataset in the project geodatabase.

3.7 Land Use Maps
Land use map data have been collected from DWR, the California Department of Conservation Farmland Mapping and Monitoring Program (FMMP), and Riverside County.

The available land use maps are indicated below:
• DWR: 2014 statewide land use mapping specifically developed for SGMA and GSPs. • FMMP: 1984, 1986, 1988, 1990, 1992, 1994, 1996, 1998, 2000, 2002, 2004, 2006, 2008, 2010, 2012, 2014, and 2016
• Riverside County: 1993 and 2000

3.8 Geologic Mapping of Surficial Geology and Faults
Surficial geology in the area of the Bedford-Coldwater Basin has been mapped by the United States Geological Survey (USGS) in the 2004 Preliminary Digital Geologic Map of the Santa Ana 30’ x 60’ Quadrangle and the 2006 Geologic Map of the San Bernardino and Santa Ana 30’ x 60’ Quadrangles. This mapped geology has been digitized into GIS formats available from the USGS, and these complete datasets are included in the Geology feature dataset of the project geodatabase.

Bedford-Coldwater Basin GSP
TM: Data Management System 4 TODD GROUNDWATER

3.9 Subsidence - NASA JPL InSAR Dataset
Vertical ground surface displacement rates are derived from Interferometric Synthetic Aperture Radar (InSAR) data collected by the European Space Agency (ESA) Sentinel-1A satellite and processed by the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL), under contract with DWR. Changes in vertical displacement can be viewed through the DWR SGMA mapping tool. Data have been downloaded from the SGMA data viewer and stored in the project geodatabase.

3.10 Water Infrastructure

3.10.1 Imported Water
Imported water delivery pipelines and tie-in locations available from Corona, EVMWD, and TVWD are included in the GIS datasets in the MunicipalWaterInfrastructure feature dataset in the project geodatabase. TVWD did not provide pipeline location details but did indicate that imported water is delivered throughout their service area. Imported water delivery data are included in the Corona Imported Water, EVMWD Imported Water, and TVWD Imported Water tables in the project database.

3.10.2 Recycled Water and Wastewater
Corona and TVWD supplied waste discharge and recycled water use records and distribution locations. EVMWD does not deliver recycled water or discharge wastewater within the basin. Corona waste discharge and recycled water distribution and use locations are included in the GIS datasets in the MunicipalWaterInfrastructure feature dataset in the project geodatabase. TVWD waste discharge historically went either to Temescal Creek or ponds adjacent to their wastewater treatment facility and they provide recycled water throughout the Bedford portion of the basin and waste discharge. Recycled water use and wastewater discharge data are included in the Corona Reclaimed Water Use, Corona Waste Discharge, TVWD All Waste Discharge, and TVWD Waste Discharge by Location tables in the project database.

3.11 Climate Data
The CIMIS stations, NOAA stations, and other climate locations are available in the geodatabase as a point coverage. In addition, the PRISM isohyets are available as a raster.

3.12 Surface Water Gage Locations
The locations of USGS surface water gages are also stored in the Geodatabase. Three streamflow gage stations near the Bedford-Coldwater Basin that are maintained by the USGS were identified. These stations are located on Temescal Creek at about Main Street in Corona (USGS 11072100), Temescal Creek at Corona Lake (USGS 11071900), and San Jacinto River near Elsinore (USGS 11070500). Up to date surface water measurements are available from the USGS NWIS data repository.

Bedford-Coldwater Basin GSP
TM: Data Management System 5 TODD GROUNDWATER

4. ACCESS DATABASES
Tabular data are linked in relational databases by subject. The DMS include one access data base with stand-alone tables that pull together data from all sources for groundwater elevation, groundwater quality, and groundwater pumping. In addition, a table containing all know wells in Bedford-Coldwater links to the subject specific tables. The well table includes locational information as State Plane coordinates. These tables that include all sources of data are named with the prefix “ALL_”. Additional tables from the individual agencies are included in the database for the records and are labels with the agency prefix (e.g. “EVMWD”, “TVWD”, “Corona”). Other tables are included to house subsets of data from other sources including the water master, EPA STORET, and data from outside the basin.

The types of data stored in the Access database are described below.

4.1 Well Information Table
Well locations and available information were collected from multiple sources, including previous investigations, USGS National Water Information System (NWIS), DWR California Groundwater Elevation Monitoring (CASGEM) program, and others. This data collection effort included available well locations, well construction information, and aquifer parameter information. Data from all the available sources for the basin and surrounding area were collected and reviewed and then the data were combined into a single unified dataset. The unified dataset retains detailed information from the source files. Well data from individual sources often use agency-specific identification numbers or names. This variation in identification number by source is problematic for organizing, relating, and querying data. A UniqueID field was added to the unified well dataset and assigned integer identification numbers for each well to serve as the primary field for joins, relating, and querying data. The unified well dataset includes wells with and without location data. In compiling these data, attempts were made to remove duplicate wells while compiling these data. In some cases of duplicate wells, it was not possible to determine which location is correct. In these instances, the duplicate records were maintained in the dataset. The unified well information dataset is included in the project database in the All_Well Information Table and the same information is presented in the project geodatabase in the Well feature class in the Groundwater feature dataset.

Well locations are not well tracked in California, and as a result it is always possible that wells are either completely missing from records or mis-located. While this is not a known data gap, there may be wells that are missing or mis-located in the data that has been compiled for this data collection task.

4.2 Groundwater Elevation Table
As with well locations, groundwater elevation records were collected from multiple sources, including previous investigations, Corona, USGS NWIS, DWR CASGEM, and others. Data from these sources were collected, reviewed, and compiled into a single unified groundwater Bedford-Coldwater Basin GSP
TM: Data Management System 6 TODD GROUNDWATER
elevation dataset. The dataset includes all information from each source and uses the UniqueID field for linking, joining, or relating to the Well Information table in the project database or Well feature class of the project geodatabase. Groundwater elevation data were not calculated for wells without reference elevation data; records for these wells include only depth to water measurements. In addition, there are temporal gaps in some of the data records between the completion of previous investigations and the start of data collection for publicly available records. This is discussed further in the data gaps section below.

Groundwater elevation data is presented in the ALL_Groundwater Elevation Data table of the project database, and this dataset has been structured according to the requirements of the CASGEM program in accordance with DWR’s grant funding agreement with the BCGSA.

4.3 Groundwater Quality Table
The groundwater quality database combines water quality data from a variety of sources for a comprehensive repository of regional water quality data. The relational database includes locations for all wells with water quality data, a table of water quality data, a table with information on the water system that was sampled, and a table of constituents monitored with agency codes, reporting levels, and applicable water quality goals. Queries are included to extract data on the key constituents of concern. Data from all three agencies, regional monitoring (Regional Water Quality Control Board and the Division of Drinking Water), and special studies (SNMP) are included in the All_Water_Quality table. The wells are linked to the Well Information table by the Unique_ID and the source recorded in the dataset attribute field.

4.4 Groundwater Pumping Table
Groundwater production in the basin was compiled from all available sources in the table ALL_BC_Annual_Pumping. Annual groundwater pumping for all wells is tracked by the Santa Ana River Watermaster, along with production in the rest of the watershed. Western Municipal Water District (WMWD) currently coordinates groundwater use data collection.

Complete records of historical groundwater use were requested from and provided by WMWD. These groundwater production data were reviewed and organized for inclusion in the project database in a table named Bedford-Coldwater Annual Pumping. These production records are related to well locations by the Unique ID in the Well Information and Bedford-Coldwater Annual Pumping tables.

Annual totals from the Watermaster were confirmed and monthly information included when available from each individual agency.

4.5 Aquifer Parameter and Well Construction Data
There are very few aquifer parameter estimates in and around the Bedford-Coldwater Basin.

Some aquifer parameter estimates were collected and/or developed during preparation of the Corona Groundwater Management Plan (Todd 2008a) and the Feasibility Study, Recycled Bedford-Coldwater Basin GSP
TM: Data Management System 7 TODD GROUNDWATER
Water Recharge, Bedford Subbasin (Todd 2008b). Most of the transmissivity and hydraulic conductivity parameter estimates from those studies were based on an empirical relationship between specific capacity and transmissivity wherein transmissivity is 1,500 times specific capacity in unconfined aquifers. However, there was a constant rate aquifer test performed on TVWD Well 1A with observations in TVWD Wells 3 and 4. The data from this test were analyzed as part of the Feasibility Study, Recycled Water Recharge, Bedford Subbasin (Todd 2008b). The TVWD Well 1A test data are included in excel workbooks in a directory named Pumping Test Data and a summary table of all available aquifer test data in included in the project database (Well Construction + Aquifer Parameters). The records in the Well Construction + Aquifer Parameter table relate to the Well Information table through the UniqueID fields.

4.6 Additional Water Sources
Additional data on imported water is stored as tables from the individual agencies in the Access database.

4.6.1 Imported Water
Corona, EVMWD, TVWD each use imported water and the measured data is stored in the database separate for each agency. There is no combined table for basin-wide imported water.

4.6.2 Recycled Water and Wastewater
Wastewater information from TVWD is stored in the database as TVWD Waste Discharge by Location. Corona’s reclaimed water use by address is stored as a separate table, Corona Reclaimed Water.

5. OTHER FORMATS

5.1 Climate Data (precipitation, evaporation, temperature) - Excel Climate data are compiled and stored as an Excel file. The workbook also calculates the cumulative departure of precipitation and local water year type by quintiles.

Bedford-Coldwater Basin GSP
TM: Data Management System 8 TODD GROUNDWATER
We identified three currently active climate monitoring stations near the Bedford-Coldwater Basin: the Lake Elsinore station maintained by the National Oceanic Atmospheric Administration (NOAA), the Santiago Peak station maintained by Orange County, and the UC Riverside California Irrigation Management Information System (CIMIS). The Lake Elsinore and UC Riverside stations include daily precipitation and evapotranspiration data; the Santiago Peak station collects monthly precipitation data. Monthly data for the Santiago Peak station is from January 1949 to current, with a slight lag on recent data. The Lake Elsinore station has daily data from January 1961 through current and the UC Riverside station has daily data from January 1986 through the present.

6. BEDFORD-COLDWATER GROUNDWATER MODEL
The groundwater model datasets prepared for the GSP are stored separately from the DMS.

These data and files have been prepared using various datasets described above, as documented in the Bedford-Coldwater GSP Model Documentation Report (Todd 2021). The results of the historical and future model simulations are documented in the GSP. Model outputs including surface water budgets and groundwater budgets are also documented in detailed tables. While these data are valuable to understanding the basin, they represent simulated conditions and are stored separately from the observed data in the DMS which are documented here.

7. DATA MANAGEMENT STORAGE
The DMS will continue to be updated with more recent data for annual reports and the GSP 5-year update. It is expected that new datasets will be added as projects and management actions are enacted to fill data gaps. For example, shallow monitoring wells near Temescal Wash may be added at a later date.

The geodatabase, Access databases, and excel workbooks will be updated annually as part of the Annual GSP Report. The GSA will maintain a copy of the annually updated files.

Appendices
City of Corona
2025 Urban Water Management Plan
Appendix R – Temescal Basin Groundwater Sustainability Plan Home Gardens
County Water District
January 2022
Temescal Basin
Groundwater
Sustainability Plan
Home Gardens
County Water District
Temescal Basin GSP
This page is intentionally blank.

TEMESCAL BASIN

GROUNDWATER

SUSTAINABILITY PLAN
January 2022
And
Temescal Basin GSP
This page is intentionally blank.

Temescal Basin GSP

SIGNATURE PAGE
_____________________________
Chad N. Taylor, PG, CHG
Principal Hydrogeologist, Todd Groundwater
_____________________________
Maureen K Reilly, PE
Senior Engineer, Todd Groundwater
_____________________________
Gus Yates, PG, CHG
Senior Hydrologist, Todd Groundwater
_____________________________
Michael P. Maley, PG, CHG, CEG, PE
Principal Hydrogeologist, Todd
Groundwater
Temescal Basin GSP i
Table of Contents
Executive Summary.............................................................................................................. ES-1 ES-1 Basin Setting ............................................................................................................. ES-1 ES-2 Groundwater Conditions.......................................................................................... ES-4 ES-3 Water Supply ............................................................................................................ ES-5 ES-4 Water Budget............................................................................................................ ES-5 ES-5 Sustainable Management Criteria ............................................................................ ES-7 ES-6 Monitoring Network ................................................................................................. ES-8 ES-7 Projects and Management Actions........................................................................... ES-8 ES-8 Implementation ........................................................................................................ ES-9 Introduction........................................................................................................................ 1-1

1.1.Purpose of the Groundwater Sustainability Plan ......................................................... 1-2

1.2.Sustainability Goal ........................................................................................................ 1-2

1.3.Agency Information ...................................................................................................... 1-2

1.4.Groundwater Sustainability Agency Information......................................................... 1-3

1.4.1.Decision Making ..................................................................................................... 1-3

1.4.2.Roles and Responsibilities...................................................................................... 1-3

1.4.3.Legal Authority of the GSA..................................................................................... 1-4

1.4.4.GSP Development Costs and Funding Sources....................................................... 1-4

1.5.GSP Organization.......................................................................................................... 1-5 Plan Area............................................................................................................................. 2-1

2.1.Geographic Area ........................................................................................................... 2-1

2.2.Land Use and Water Management Jurisdictional Agencies......................................... 2-1

2.2.1.Counties.................................................................................................................. 2-2

2.2.2.Cities....................................................................................................................... 2-2

2.2.3.Federal.................................................................................................................... 2-2

2.2.4.State ....................................................................................................................... 2-2

2.2.5.Conservation Easements........................................................................................ 2-3

2.2.6.Water Management Entities.................................................................................. 2-3

2.3.Water Supply ................................................................................................................ 2-4

2.3.1.Water Providers ..................................................................................................... 2-4 Temescal Basin GSP ii

2.3.2.Water Supply Sources ............................................................................................ 2-4

2.3.3.Water Use Sectors.................................................................................................. 2-6

2.4.Water Resources Monitoring Programs....................................................................... 2-7

2.4.1.Climate ................................................................................................................... 2-8

2.4.2.Surface Water Flows .............................................................................................. 2-8

2.4.3.Surface Water Quality ............................................................................................ 2-8

2.4.4.Groundwater Levels............................................................................................... 2-9

2.4.5.Groundwater Quality ............................................................................................. 2-9

2.4.6.Groundwater Production ....................................................................................... 2-9

2.4.7.Conjunctive Use/Managed Recharge................................................................... 2-10

2.4.8.Recycled Water .................................................................................................... 2-10

2.4.9.Imported Water.................................................................................................... 2-10

2.4.10.Land use ............................................................................................................. 2-10

2.4.11.Natural Resources.............................................................................................. 2-10

2.4.12.Land subsidence ................................................................................................. 2-10

2.4.13.Incorporation of Existing Monitoring into GSP .................................................. 2-11

2.5.Water Resources Management.................................................................................. 2-11

2.5.1.AB3030 Groundwater Management Plan ............................................................ 2-11

2.5.2.Groundwater Monitoring Program and Protocols............................................... 2-12

2.5.3.Recharge Master Plan for the Temescal Basin..................................................... 2-12

2.5.4.Water Quality Control Plan for the Santa Ana River Basin .................................. 2-13

2.5.5.Integrated Regional Water Management Plan Update ....................................... 2-13

2.5.6.Santa Ana River Watershed One Water One Watershed Plan............................. 2-14

2.5.7.Corona and Norco Urban Water Management Plans.......................................... 2-15

2.5.8.Reclaimed Water Master Plan.............................................................................. 2-15

2.5.9.Water Resources Management Implementation Status...................................... 2-15

2.6.General Plans.............................................................................................................. 2-15

2.6.1.Riverside County General Plan............................................................................. 2-16

2.6.2.City of Corona General Plan ................................................................................. 2-16

2.6.3.City of Norco General Plan ................................................................................... 2-19

2.6.4.General Plan Influences on Groundwater Sustainability Agency Ability to Achieve Sustainability ................................................................................................................. 2-19

2.6.5.GSP Influences on General Plans.......................................................................... 2-20 Temescal Basin GSP iii

2.7.Additional GSP Elements............................................................................................ 2-20

2.7.1.Wellhead Protection Areas and Recharge Areas ................................................. 2-21

2.7.2.Groundwater Contamination Migration and Clean-up........................................ 2-21

2.7.3.Well Permitting, Construction, and Destruction Requirements.......................... 2-22

2.7.4.Efficient Water Management Practices ............................................................... 2-23

2.7.5.Relationships with State and Federal Agencies ................................................... 2-23

2.7.6.Land Use Plan Coordination ................................................................................. 2-23

2.8.Notice and Communication........................................................................................ 2-23

2.8.1.Technical Advisory Committee (TAC)................................................................... 2-24

2.8.2.Public Workshops................................................................................................. 2-25

2.8.3.Directed Outreach and Coordination................................................................... 2-25

2.8.4.Disadvantaged Community Outreach .................................................................. 2-25

2.8.5.Neighboring Basin Coordination .......................................................................... 2-25

2.8.6.Comments and Responses on Draft GSP.............................................................. 2-25 Hydrogeological Conceptual Model ................................................................................... 3-1

3.1.Physical Setting and Topography.................................................................................. 3-1

3.2.Surface Water Features................................................................................................ 3-2

3.3. Soils............................................................................................................................. 3-2

3.4.Geologic Setting............................................................................................................ 3-3

3.5.Faults ............................................................................................................................ 3-3

3.6.Aquifers......................................................................................................................... 3-3

3.6.1.Description of Principal Aquifer Units.................................................................... 3-4

3.6.2.Description of Lateral Boundaries.......................................................................... 3-6

3.7.Structures Affecting Groundwater ............................................................................... 3-6

3.8.Definable Basin Bottom................................................................................................ 3-6

3.9.Recharge and Discharge Areas..................................................................................... 3-7

3.10.Primary Groundwater Uses........................................................................................ 3-7

3.11.Data Gaps in the Hydrogeologic Conceptual Model .................................................. 3-8 Current and Historical Groundwater Conditions................................................................ 4-1

4.1.Groundwater Elevations............................................................................................... 4-1

4.1.1.Available Data......................................................................................................... 4-1

4.1.2.Groundwater Occurrence ...................................................................................... 4-1

4.1.3.Groundwater Elevations and Trends...................................................................... 4-2 Temescal Basin GSP iv

4.1.4.Groundwater Flow ................................................................................................. 4-3

4.1.5.Vertical Groundwater Gradients............................................................................ 4-4

4.2.Changes In Groundwater Storage ................................................................................ 4-4

4.3.Land Subsidence and Potential for Subsidence............................................................ 4-5

4.3.1.Interferometric Synthetic Aperture Radar (InSAR) ................................................ 4-6

4.4.Groundwater Quality.................................................................................................... 4-6

4.5.Key Constituents of Concern ........................................................................................ 4-8

4.5.1.Total Dissolved Solids (TDS) ................................................................................... 4-9

4.5.2.Nitrate as Nitrate (NO3).......................................................................................... 4-9

4.6.Other Constituents..................................................................................................... 4-10

4.6.1.Naturally Occurring Contaminants....................................................................... 4-10

4.6.2.1,2,3- Trichloropropane ....................................................................................... 4-11

4.6.3.Per- and Polyfluoroalkyl Substances (PFAS)......................................................... 4-11

4.6.4.Monitoring Networks........................................................................................... 4-12

4.7.Threats to Water Quality............................................................................................ 4-13

4.7.1.Regulated Facilities............................................................................................... 4-13

4.7.2.Septic Systems...................................................................................................... 4-13

4.7.3.Non-point Sources................................................................................................ 4-13

4.8.Vertical Variations in Water Quality........................................................................... 4-13

4.9.Seawater Intrusion Conditions ................................................................................... 4-13

4.10.Interconnection of Surface Water and Groundwater............................................... 4-13

4.10.1.Stream Flow Measurements.............................................................................. 4-14

4.10.2.Depth to Groundwater....................................................................................... 4-16

4.10.3.Riparian Vegetation............................................................................................ 4-17

4.10.4.Wetlands and Interconnected Surface Water ................................................... 4-19

4.10.5.Animals and Interconnected Surface Water...................................................... 4-22 Water Budget...................................................................................................................... 5-1

5.1.Water Budget Methodology......................................................................................... 5-1

5.2.Dry and Wet Periods..................................................................................................... 5-1

5.3.Water Balance Analysis Periods ................................................................................... 5-2

5.4.Management Areas...................................................................................................... 5-3

5.5.Methods of Analysis ..................................................................................................... 5-3

5.5.1.Rainfall-Runoff-Recharge Model............................................................................ 5-3 Temescal Basin GSP v

5.5.2.Groundwater Model............................................................................................... 5-4

5.5.3.Simulation of Future Conditions ............................................................................ 5-5

5.6.Surface Water Balance ............................................................................................... 5-10

5.6.1.Inflows to Surface Water...................................................................................... 5-12

5.6.2.Outflows of Surface Water................................................................................... 5-13

5.7.Groundwater Balance................................................................................................. 5-14

5.7.1.Inflows to Groundwater....................................................................................... 5-17

5.7.2.Outflows from Groundwater................................................................................ 5-19

5.8.Change in Groundwater Storage ................................................................................ 5-20

5.9.Estimate of Sustainable Yield ..................................................................................... 5-20 Sustainable Management Criteria...................................................................................... 6-1

6.1.Sustainability Goal ........................................................................................................ 6-2

6.1.1.Description of Sustainability Goal .......................................................................... 6-2

6.1.2.Approach to Sustainability Indicators.................................................................... 6-2

6.1.3.Summary of Sustainable Management Criteria ..................................................... 6-4

6.2.Chronic Lowering of Groundwater Levels.................................................................... 6-5

6.2.1.Description of Undesirable Results........................................................................ 6-5

6.2.2.Potential Causes of Undesirable Results................................................................ 6-6

6.2.3.Definition of Undesirable Results........................................................................... 6-7

6.2.4.Potential Effects on Beneficial Uses and Users...................................................... 6-7

6.2.5.Sustainable Management Criteria for Groundwater Levels................................... 6-7

6.2.6.Minimum Thresholds ............................................................................................. 6-9

6.2.7.Measurable Objectives......................................................................................... 6-13

6.3.Reduction of Groundwater Storage ........................................................................... 6-13

6.3.1.Description of Undesirable Results...................................................................... 6-14

6.3.2.Potential Causes of Undesirable Results.............................................................. 6-14

6.3.3.Definition of Undesirable Results......................................................................... 6-14

6.3.4.Potential Effects on Beneficial Uses and Users.................................................... 6-15

6.3.5.Sustainable Management Criteria for Groundwater Storage.............................. 6-15

6.3.6.Minimum Threshold............................................................................................. 6-16

6.3.7.Measurable Objectives......................................................................................... 6-18

6.4.Seawater Intrusion ..................................................................................................... 6-19

6.5.Land Subsidence ......................................................................................................... 6-19 Temescal Basin GSP vi

6.5.1.Description of Undesirable Results...................................................................... 6-20

6.5.2.Potential Causes of Undesirable Results.............................................................. 6-20

6.5.3.Potential Effects on Beneficial Uses and Users.................................................... 6-21

6.5.4.Minimum Threshold............................................................................................. 6-21

6.5.5.Measurable Objectives......................................................................................... 6-23

6.6.Degradation of Water Quality .................................................................................... 6-24

6.6.1.Potential Causes of Undesirable Results.............................................................. 6-24

6.6.2.Description of Undesirable Results...................................................................... 6-25

6.6.3.Potential Effects on Beneficial Uses and Users.................................................... 6-25

6.6.4.Sustainable Management Criteria for Groundwater Quality............................... 6-26

6.6.5.Minimum Thresholds ........................................................................................... 6-26

6.6.6.Measurable Objectives......................................................................................... 6-30

6.7.Depletions of Interconnected Surface Water............................................................. 6-31

6.7.1.Description of Undesirable Results...................................................................... 6-32

6.7.2.Potential Causes of Undesirable Results.............................................................. 6-32

6.7.3.Definition of Undesirable Results......................................................................... 6-33

6.7.4.Potential Effects on Beneficial Uses and Users.................................................... 6-33

6.7.5.Sustainable Management Criteria for Interconnected Surface Water................ 6-34

6.7.6.Minimum Threshold............................................................................................. 6-34

6.7.7.Measurable Objective .......................................................................................... 6-36

6.7.8.Data Gaps............................................................................................................. 6-37 Monitoring Network........................................................................................................... 7-1

7.1.Description of Monitoring Network ............................................................................. 7-1

7.1.1.Chronic Lowering of Groundwater Levels.............................................................. 7-3

7.1.2.Reduction of Groundwater in Storage ................................................................... 7-3

7.1.3.Seawater Intrusion ................................................................................................. 7-5

7.1.4.Subsidence ............................................................................................................. 7-5

7.1.5.Degraded Water Quality ........................................................................................ 7-6

7.1.6.Depletion of Interconnected Surface Water.......................................................... 7-7

7.2.Protocols for Data Collection and Monitoring.............................................................. 7-8

7.2.1.Field Methods for Monitoring Well Data ............................................................... 7-8

7.2.2.Field Methods for Groundwater Elevation Monitoring ......................................... 7-8

7.2.3.Field Methods for Groundwater Quality Monitoring............................................. 7-9 Temescal Basin GSP vii

7.3.Representative Monitoring ........................................................................................ 7-10

7.4.Data Management System (DMS) .............................................................................. 7-10

7.5.Assessment and Improvement of Monitoring Network............................................. 7-10

7.5.1.Identification and Description of Data Gaps........................................................ 7-11

7.5.2.Description of Steps to Fill Data Gaps.................................................................. 7-11 Projects and Management Actions .................................................................................... 8-1

8.1.Group 1 Projects........................................................................................................... 8-3

8.1.1.Groundwater Treatment........................................................................................ 8-3

8.1.2.Water Reclamation Facility (WRF) Percolation Ponds........................................... 8-4

8.1.3.Water Level Quality Assurance and Quality Control (QA/QC) ............................... 8-4

8.1.4.Water Shortage Contingency Plans........................................................................ 8-5

8.1.5.Water Conservation Program ................................................................................ 8-5

8.1.6.Participation in Integrated Regional Water Management Plans (IRWMP)............ 8-6

8.1.7.Western Riverside County Regional Wastewater Authority (WRCRWA)............... 8-7

8.1.8.Santa Ana Watershed Involvement........................................................................ 8-7

8.2.Group 2 Projects........................................................................................................... 8-8

8.2.1.Shallow Monitoring Well Installation..................................................................... 8-8

8.2.2.Potable Reuse Feasibility Study.............................................................................. 8-9

8.2.3.Mountain Runoff Capture Feasibility Study ......................................................... 8-11

8.3.Group 3 Projects......................................................................................................... 8-12

8.3.1.Groundwater Treatment...................................................................................... 8-12

8.3.2.Stormwater Capture, Treatment, and Recharge.................................................. 8-12

8.3.3.Santa Ana River Wastewater Discharge Coordination for Shallow Groundwater Conditions...................................................................................................................... 8-13 Implementation Plan .......................................................................................................... 9-1

9.1.Plan Implementation Resources and Responsibilities.................................................. 9-1

9.2.Annual Reporting.......................................................................................................... 9-1

9.3.New Information and Changes..................................................................................... 9-2

9.4.Periodic Evaluations ..................................................................................................... 9-2

9.5.Projects and Management Actions .............................................................................. 9-3

9.6.Schedule For Implementation ...................................................................................... 9-4

9.7.GSP Implementation Costs........................................................................................... 9-6

9.7.1.Funding Methods ................................................................................................... 9-6 Temescal Basin GSP viii
References ............................................................................................................... 10-1 List of Tables
Table 1-1. GSP Preparation Checklist..................................................................................... 1-7 Table 2-1. Water Use and Land Use by Sector (2020)1 .......................................................... 2-7 Table 2-2. Select Policies in the Riverside County General Plan.......................................... 2-17 Table 2-3. Selected Policies in the City of Corona General Plan.......................................... 2-18 Table 2-4. Selected Policies in the City of Norco General Plan............................................ 2-19 Table 2-5. Additional GSP Elements included in Water Code Section 10727.4................... 2-21 Table 2-6. Status of Contamination Sites in the Basin......................................................... 2-22 Table 5-1. Water Year Type Classification ............................................................................. 5-2 Table 5-2. Temescal Basin Land Use in 1990, 2018, and 2068 (acres) .................................. 5-9 Table 5-3. Annual Surface Water Budgets for the Temescal Basin 1990 to 2018 ............... 5-11 Table 5-4. Average Annual Groundwater Budgets.............................................................. 5-16 Table 5-5. Estimated Sustainable Yield................................................................................ 5-21 Table 6-1. Minimum Thresholds for Groundwater Levels................................................... 6-10 Table 6-2. Summary of Current Conditions for Nitrate (NO3) and TDS ............................... 6-27 Table 7-1. Temescal Monitoring Program Summary ............................................................. 7-2 Table 7-2. Wells in the Temescal GSA Monitoring Network.................................................. 7-4 Table 7-3. Identification and Description of Data Gaps....................................................... 7-11 Table 8-1 Summary of Projects and Management Actions ................................................... 8-2 Table 8-2. Existing and Projected Corona Groundwater Extraction Volumes (AFY).............. 8-3 Table 8-3. WRF Annual Percolation Pond Contributions (AFY).............................................. 8-4 Table 8-4. WSCP Shortage Level Determination.................................................................... 8-5 Table 8-5. City of Corona Santa Ana Watershed Task Forces/Groups................................... 8-7 Table 9-1. Estimated Timeline for Projects and Management Actions................................. 9-5 Table 9-2. GSP Implementation Cost Estimates .................................................................... 9-6 List of Figures
Figure ES-1. Temescal Basin................................................................................................. ES-2 Figure ES-2. Channel Aquifer ............................................................................................... ES-3 Figure ES-3. Representative Hydrograph, Corona Well 15.................................................. ES-4 Temescal Basin GSP ix
Figure 1-1. Temescal Groundwater Basin, GSA, and Adjacent Basins................................. 1-10 Figure 2-1. Temescal Basin GSP Area................................................................................... 2-27 Figure 2-2. Jurisdictional Areas............................................................................................ 2-28 Figure 2-3. Federal and State Lands..................................................................................... 2-29 Figure 2-4. Water Supply Sources within Basin - 2020 ........................................................ 2-30 Figure 2-5. Basin Domestic Groundwater Wells.................................................................. 2-31 Figure 2-6. Basin Production Groundwater Wells ............................................................... 2-32 Figure 2-7. Basin Public Groundwater Wells ....................................................................... 2-33 Figure 2-8. All Basin Groundwater Wells............................................................................. 2-34 Figure 2-9. Corona and Norco Facilities............................................................................... 2-35 Figure 2-10. Existing Land Use ............................................................................................. 2-36 Figure 2-11. 1984 Land Use ................................................................................................. 2-37 Figure 2-12. Disadvantaged and Severely Disadvantaged Communities............................. 2-38 Figure 3-1. Basin Topography ................................................................................................ 3-9 Figure 3-2. Tributary Surface Water in Basin....................................................................... 3-10 Figure 3-3. Watersheds Tributary to Basin .......................................................................... 3-11 Figure 3-4. Basin Soil Hydrologic Properties........................................................................ 3-12 Figure 3-5. Surficial Geology ................................................................................................ 3-13 Figure 3-6. Cross Section Line Orientation .......................................................................... 3-14 Figure 3-7. Cross Section A to A’.......................................................................................... 3-15 Figure 3-8. Cross Section B to B’ .......................................................................................... 3-16 Figure 3-9. Cross Section C to C’ .......................................................................................... 3-17 Figure 3-10. Channel Aquifer Extent and Hydraulic Conductivity ....................................... 3-18 Figure 3-11. Depth to Bedrock............................................................................................. 3-19 Figure 3-12. Groundwater Recharge and Discharge Areas.................................................. 3-20 Figure 4-1. Historically Monitored Wells............................................................................. 4-24 Figure 4-2. Representative Hydrographs City of Corona Well 15........................................ 4-25 Figure 4-3. Representative Hydrographs City of Corona Well 11........................................ 4-26 Figure 4-4. Representative Hydrographs City of Corona Well 22........................................ 4-27 Figure 4-5. Representative Hydrographs City of Corona Well 19........................................ 4-28 Figure 4-6. Representative Hydrographs City of Corona Well 26........................................ 4-29 Figure 4-7. Representative Hydrographs City of Corona Well 17A...................................... 4-30 Figure 4-8. Representative Hydrographs City of Corona Well 8A........................................ 4-31 Temescal Basin GSP x
Figure 4-9. Representative Hydrographs City of Corona Well 13........................................ 4-32 Figure 4-10. Groundwater Elevation Contours, Fall 2015 ................................................... 4-33 Figure 4-11. Groundwater Elevation Contours, Spring 2017............................................... 4-34 Figure 4-12. Concepts of Land Subsidence .......................................................................... 4-35 Figure 4-13. Basin-Wide Subsidence Estimates from Satellite Measurements................... 4-36 Figure 4-14. Wells with Water Quality Data ........................................................................ 4-37 Figure 4-15. Total Dissolved Solids Concentrations in Wells, Water Years 2011 - 2019 ..... 4-38 Figure 4-16. Nitrate Concentrations in Wells, Water Years 2011 through 2019................. 4-39 Figure 4-17. Regional Surface Water Features.................................................................... 4-40 Figure 4-18. Stream Flow at Four Gages.............................................................................. 4-41 Figure 4-19. Temescal Wash Flow and Reclaimed Water Discharge................................... 4-42 Figure 4-20. Depth to Water Spring 2017............................................................................ 4-43 Figure 4-21. Critical Habitat Areas....................................................................................... 4-44 Figure 4-22. Historical Maximum Depth to Water Near Prado Wetlands........................... 4-45 Figure 4-23. Factors Related to Prado Wetland Groundwater Levels................................. 4-46 Figure 5-1. Cumulative Departure of Annual Precipitation at Lake Elsinore....................... 5-23 Figure 5-2. Effect of Climate Change on Precipitation and Evapotranspiration.................. 5-24 Figure 5-3. Land Use in 2018................................................................................................ 5-25 Figure 5-4. Surface Water Budgets 1990 through 2018 ...................................................... 5-26 Figure 5-5. Effect of Clipping on Simulated Tributary Stream Flow..................................... 5-27 Figure 5-6. Annual Groundwater Budgets 1990 to 2018..................................................... 5-28 Figure 5-7. Annual Groundwater Budgets Future Baseline ................................................. 5-29 Figure 5-8. Annual Groundwater Budgets, Growth Plus Climate Change ........................... 5-30 Figure 5-9. Dispersed Recharge ........................................................................................... 5-31 Figure 5-10. Cumulative Storage Changes 1990 to 2068..................................................... 5-32 Figure 6-1. Water Level Key Wells....................................................................................... 6-38 Figure 7-1. Groundwater Level Monitoring Wells............................................................... 7-12 Figure 7-2. Water Quality Monitoring Wells........................................................................ 7-13 Figure 8-1. Potential Shallow Monitoring Well Locations ................................................... 8-14 Temescal Basin GSP xi
Appendices (following text)
Appendix A – Memorandum of Understanding forming the Temescal Groundwater Sustainability Agency
Appendix B – Temescal GSA Notice of Decision to become a Groundwater Sustainability Agency
Appendix C – Groundwater Sustainability Plan Elements Guide Appendix D – Temescal Groundwater Sustainability Plan Stakeholder Outreach Plan Appendix E – List of Public Meetings During GSP Development and GSP Comments and Responses
Appendix F – Summaries of Technical Advisory Committee Meetings Appendix G – Summaries of Public Workshops and Associated Fact Sheets Appendix H – Summaries of Neighboring Basin Coordination and Community Leader Outreach Meetings
Appendix I – Draft GSP Comments and Responses
Appendix J – Temescal Groundwater Sustainability Plan Numerical Groundwater Model Documentation Report
Appendix K – Detailed Annual Surface and Groundwater Budgets Appendix L – Temescal Groundwater Sustainability Plan Data Management System Description
Temescal Basin GSP xii
Acronyms
1,2,3-TCP 1,2,3- Trichloropropane
AF acre-feet
AFY acre-feet per year
Basin Plan Water Quality Control Plan for the Santa Ana River Basin Basin Temescal Subbasin
BMP Best management practices
CASGEM California Statewide Groundwater Elevation Monitoring CDA Chino Desalter Authority
CEQA California Environmental Quality Act
cfs cubic feet per second
cfs/mi cubic feet per second per mile
CIMIS California Irrigation Management Information System COC constituent of concern
Corona City of Corona
DAC disadvantaged community
DBP disinfection byproduct
DDW State Water Resources Control Board Division of Drinking Water DMS Data Management System
DWR California Department of Water Resources
DWSAP Drinking Water Source Water Assessment Program
ET Evapotranspiration
ETo Reference evapotranspiration
ft feet
ft/day feet per day
GAMA Groundwater Ambient Monitoring and Assessment
GDE groundwater dependent ecosystem
GIS geographic information system
gpcd gallons per-capita per day
gpd/ft2 gallons per day per square foot
GPS global positioning system
GSA Groundwater Sustainability Agency
GSP Groundwater Sustainability Plan
GWMP Groundwater Management Plan
HCP habitat conservation plan
HGCWD Home Gardens County Water District
in/yr inches per year
InSAR Synthetic Aperture Radar
IRWMP Integrated Regional Water Management Plan
JPA joint powers authority
K hydraulic conductivity
km2 square kilometers
LSCE Luhdorff and Scalmanini Consulting Engineers
Temescal Basin GSP xiii
M&I Municipal, commercial, and industrial
MA Management Area
MCL Maximum Contaminant Level
Met Metropolitan Water District of Southern California
mg/L milligrams per liter
mgd million gallons per day
mi2 square miles
mm millimeter
MO Measurable Objective
MODFLOW United States Geological Survey modular finite-difference flow model
MOU Memorandum of Understanding
MSHCP Western Riverside County Multiple Species Habitat Conservation Plan
msl mean sea level
MT Minimum Threshold
NAD83 North American Datum of 1983
NAVD88 North American Vertical Datum of 1988
NCCAG Natural Communities Commonly Associated with Groundwater NDMI Normalized Difference Moisture Index
NDVI Normalized Difference Vegetation Index
NO3 nitrate
NOAA National Oceanic and Atmospheric Administration
Norco City of Norco
NPS nonpoint source
NRCS U.S. Department of Agriculture, Natural Resources Conservation Service
NTU Nephelometric Turbidity Unit
NWIS National Water Information System
O&M operation and maintenance
ORP oxidation-reduction potential
Outreach Plan Stakeholder Outreach Plan
OWOW Plan One Water One Watershed Plan
OWTS On-Site Wastewater Treatment System
PCE Tetrachloroethylene
pCi/L picocuries per liter
PFAS per and polyfluoroalkyl substances
PFOA perfluorooctanoic acid
PFOS perfluorooctane sulfonate
PLSS Public Land Survey System
POTW publicly owned treatment works
ppt parts per trillion
PVC polyvinyl chloride
QA/QC Quality Assurance and Quality Control
Temescal Basin GSP xiv
RCDEH Riverside County Department of Environmental Health RCFCWCD Riverside County Flood Control and Water Conservation District RFP request for proposals
RMP Recharge Master Plan
RO reverse osmosis
RWMP Reclaimed Water Master Plan
RWQCB Santa Ana Regional Water Quality Control Board
SAR Santa Ana River
SARHCP Upper Santa Ana River Habitat Conservation Plan
SARWQCB Santa Ana Regional Water Quality Control Board
SAWPA Santa Ana Watershed Project Authority
SCAG Southern California Association of Governments
SDAC severely disadvantaged community
SFR Streamflow Routing Package
SGMA Sustainable Groundwater Management Act
SMCL Secondary maximum contaminant level
SNMP Salt and Nutrient Management Plan
SSURGO Soil Survey Geographic Database
SWP State Water Project
SWRCB State Water Resources Control Board
TAC Technical Advisory Committee
TCE Trichloroethylene
TCP 1,2,3-Trichloropropane
TDS total dissolved solids
Temescal GSA Temescal Groundwater Sustainability Agency TMDL Total Maximum Daily Load
TSS total suspended solids
TVWD Temescal Valley Water District
µg/L micrograms per liter
USBR United States Bureau of Reclamation
USDA United States Department of Agriculture
USEPA United State Environmental Protection Agency
USFS United States Forest Service
USGS United States Geological Survey
UWMP Urban Water Management Plan
VOCs volatile organic compounds
WMWD Western Municipal Water District
WRCRWA Western Riverside County Regional Wastewater Authority WRF Water Reclamation Facility
WSCP water shortage contingency plan
Temescal Basin GSP xv
This page is intentionally blank.

Temescal Basin GSP ES-1

EXECUTIVE SUMMARY
The Sustainable Groundwater Management Act (SGMA) requires local agencies in groundwater basins designated as high- or medium-priority to form Groundwater Sustainability Agencies (GSAs) and develop a Groundwater Sustainability Plan (GSP) to plan for achieving and/or maintaining sustainability within 20 years of implementing the plan.

The Temescal Groundwater Subbasin (Basin) has been designated by the California Department of Water Resources (DWR) as medium priority and must prepare a GSP.

Wishing to provide a framework for cooperative groundwater management and SGMA compliance, the City of Corona (Corona), City of Norco (Norco), and the Home Gardens County Water District (HGCWD) executed a Memorandum of Understanding (MOU) in March 2017 establishing the Temescal Basin Groundwater Sustainability Agency (Temescal GSA). In August 2017, the Temescal GSA became the GSA for the Basin by submitting a formation notice to DWR. While Corona is leading this effort, the GSP will be developed jointly among the three agencies, with coordinated implementation toward sustainable management.

ES-1 BASIN SETTING
Figure ES-1 shows the Basin located in western Riverside County. Figure ES-1 also shows the adjacent Bedford Coldwater, Chino, and Riverside-Arlington Subbasins of the Upper Santa Ana Groundwater Basin and the Coastal Plain of Orange County Basin. The Temescal Basin is bounded on the west by the Santa Ana Mountains and the east by low-lying El Sobrante de San Jacinto and La Sierra hills.

The Basin is located within one of the structural blocks of the Peninsular Ranges of Southern California. The Basin occurs in a linear low-lying block, referred to as the Elsinore-Temecula trough, between the Santa Ana Mountains on the west and the Perris Plain on the east (Todd and AKM 2008). The trough extends from Corona to the southeast some 30 miles and was formed along an extensive northwest-southeast trending fault zone including the Elsinore, Chino, and related faults. The Elsinore and Chino fault zones bound the Basin on the west and trend along the mountain fronts.

The basin-fill alluvial deposits and, to some extent, the underlying sedimentary units make up the aquifers in the Basin. However, these deposits do not fall neatly into two categories of permeability, such as bedrock and basin fill. Aquifer packages composed of various geologic units have been defined based on depositional environment, degree of consolidation, groundwater production, and location throughout the Basin.

Three aquifer packages provide water supply to wells in Basin: the Channel Aquifer, the Alluvial Fan aquifers, and, to a lesser extent, consolidated sandstone aquifers (Todd and AKM 2008). Of these three aquifers, the Channel Aquifer is the only principal aquifer as it the most productive aquifer and provides most of the groundwater supply in the Basin, Figure ES-2.

Temescal Basin GSP ES-2
Figure ES-1. Temescal Basin
Temescal Basin GSP ES-3
Figure ES-2. Channel Aquifer
Temescal Basin GSP ES-4
ES-2 GROUNDWATER CONDITIONS
Water levels in the Channel Aquifer vary in response to wet and dry hydrologic cycles.

Increased pumping and prolonged drought have resulted in a slight decline in water levels over the past twenty years. Groundwater levels reached their respective highs in the early 1980s in response to a wet hydrologic cycle that began in 1978. These higher levels also correlate to a period of relatively low pumping in the Basin. During a later wet cycle from 1992 to 1998, water levels did not recover to 1980s levels, likely related to an increase in Basin pumping. The lowest groundwater levels generally correspond to dry periods and periods of increased pumping, though the responses throughout the Basin are not uniform.

Figure ES-3. Representative Hydrograph, Corona Well 15
Temescal Basin GSP ES-5
1980s levels; pumping in the Basin had increased in this period. Hydrographs from most wells show lowering water levels from 2000 to 2004, a period that was not hydrologically dry but had increased pumping in Corona. In the Well 15 hydrograph, the lowest water levels occurred during the 2015 to 2017 period, during and following drought conditions.

There have been slight increases since then in 2018 through 2019 due in part to increased precipitation after 2015.

Total Dissolved Solids (TDS) and nitrate are the primary constituents of concern in the Basin.

Groundwater in the Basin is somewhat mineralized, with high TDS concentrations in many monitored wells. Recent average TDS concentrations in the Basin are above the 500 milligrams per liter (mg/L) lower secondary maximum contaminant level (SMCL) for drinking water, but below the upper SMCL of 1,000 mg/L.

Groundwater in the Basin has been impacted by human activities both in the Basin and watershed including agricultural, urban, and industrial land uses. Elevated nitrate concentrations have been documented in the Basin since at least the 1950s. Recent average nitrate as nitrate (NO3) concentrations in the Basin are moderate; the recent average concentration in the Basin is 42.8 mg/L. The maximum contaminant level (MCL) for nitrate as NO3 in drinking water is 45 mg/L.

ES-3 WATER SUPPLY
Sources of water supply for agricultural, municipal and industrial (M&I), and domestic uses include groundwater, imported water, and recycled water. Metropolitan Water District of Southern California (Met) is the wholesaler for imported water and its sources of water include the Colorado River and the State Water Project. Both Corona and Norco receive imported water from Met for distribution in the Basin.

Groundwater has been an important component of water supply in the Basin for more than 100 years. Until the 1970s, most of the groundwater production in the Basin was for agricultural supply. A few well owners have also produced small amounts of groundwater for domestic and industrial use. There are no current private domestic groundwater users in the Basin. Production for municipal supply increased in the 1960s and 1970s and continues today.

For more than 50 years, Corona and HGCWD have relied on groundwater from the Basin for municipal uses, and these agencies have long been responsible for managing groundwater conditions in the Basin. Norco has also relied on groundwater but their wells are located outside of the Temescal Basin (in the unadjudicated portion of the Chino Subbasin). Corona, in coordination with HGCWD and Norco, adopted a Groundwater Management Plan (GWMP) in 2008 that covers the Basin.

ES-4 WATER BUDGET
A water balance (or water budget) is a quantitative tabulation of all inflows, outflows, and storage change of a hydrologic system. This GSP contains a detailed water balance for both the groundwater system and surface water system of the Basin. The water budgets were Temescal Basin GSP ES-6
developed for time periods representing historical, current, future no project (baseline), and future growth plus climate change (growth plus climate change) conditions.

Surface water and other inflows came from multiple sources. Monthly inflows in Temescal Wash were obtained from the baseline and growth plus climate change simulations produced by the Bedford-Coldwater Subbasin groundwater model (Todd, H&H, and Stantec 2021), which is concurrently being used to develop the GSP for that subbasin. Small stream and bedrock inflows simulated for 1993 to 2017 of the calibration model period were repeated twice to obtain 50 years of data.

In the historical model, the Basin water budgets were overall negative for the historical and current analysis periods, due to a variety of reasons and reflecting the different time periods. Storage declines during the early years of the simulation may have resulted from incorrectly estimated initial water levels. During 2000 to 2011, relatively high amounts of municipal groundwater pumping might have caused a gradual decrease in storage. Since 2011, the predominantly dry climatic conditions have resulted in reduced inflows and thus a decrease in storage. These historical storage declines have not resulted in undesirable results related to water levels or groundwater storage in the Basin to date. Most groundwater production in the Basin is for Corona municipal use, and Corona and the other GSA agencies have a portfolio of alternative water supply sources for future use.

Two future scenarios were simulated to test sustainability. In the baseline scenario, land use remains the same as the current conditions. The growth plus climate change scenario incorporated anticipated effects of climate change, urban development, and associated changes in water and wastewater management.

In both future scenarios, the total pumping was adjusted to pump within the sustainable yield of the Basin; the remaining municipal water demand will be supplied by imported and recycled water. Simulating pumping within the sustainable yield of the Basin in the groundwater model produced essentially no long-term storage change in the future baseline simulation.

Growth and climate change had relatively small effects that tended to offset each other. The warmer, drier climatic conditions tended to decrease stream percolation and rainfall recharge. Urban growth—much of which is projected to be in tributary watershed areas— tended to increase recharge because of irrigation deep percolation, pipe leaks and percolation of runoff from disconnected impervious areas. Notably, total water use and percolation of reclaimed water were assumed not to change appreciably, consistent with assumptions in the Corona’s Urban Water Management Plan (UWMP) (Michael Baker 2021) that population growth will be offset by decreases in per-capita water use. Consequently, individual inflows and outflows in the growth plus climate change scenario were identical to or very close to the values in the future baseline scenario.

Average annual storage changes during both future scenarios were very slightly positive, with total inflows about34 AFY greater than total outflows. This was the intentional result of adjusting Corona pumping to achieve close to zero net storage change during 2019 to 2068.

Temescal Basin GSP ES-7
ES-5 SUSTAINABLE MANAGEMENT CRITERIA
The sustainable management goal of the Temescal Basin is to sustain groundwater resources for the current and future beneficial uses of the Basin in a manner that is adaptive and responsive to the following objectives:
• Provide a long-term, reliable and efficient groundwater supply for municipal, industrial, and other uses
• Provide reliable storage for water supply resilience during droughts and shortages • Protect groundwater quality
• Support beneficial uses of interconnected surface waters, and • Support integrated and cooperative water resource management.

This goal is consistent with SGMA and is based on information from the Plan Area, Hydrogeologic Conceptual Model, Groundwater Conditions, and Water Budget sections of this GSP that:
• Identify beneficial uses of Temescal Basin groundwater and document the roles of local water and land use agencies
• Describe the local hydrogeologic setting, groundwater quality conditions, groundwater levels and storage, and inflows and outflows of the Basin • Document the ongoing water resource monitoring and conjunctive management of groundwater, local surface water, recycled water, and especially imported water sources that help protect groundwater quality and maintain water supply.

A GSP must develop quantitative sustainability criteria for all applicable sustainability indicators that allow the GSA to define, measure, and track sustainable management. These criteria include the following:
• Undesirable Result – significant and unreasonable conditions for any of the six sustainability indicators.
• Minimum Threshold (MT) – numeric value used to define undesirable results for each sustainability indicator.
• Measurable Objective (MO) – specific, quantifiable goal to track the performance of sustainable management.

The sustainability indicators and sustainable management criteria are clearly defined and provide a quantitative analysis of the Basin’s sustainability. As the Basin has been managed without significant undesirable results, the following sustainability criteria are defined to avoid future undesirable results:
• The Minimum Threshold for defining undesirable results relative to chronic lowering of groundwater levels is defined at each Key Well by historical groundwater low levels. Undesirable results are indicated when two consecutive exceedances occur in each of two consecutive years, in sixty percent or more of the Key Wells.

Temescal Basin GSP ES-8
• The Minimum Threshold for reduction of groundwater storage for all Management Areas is fulfilled by the minimum threshold for groundwater levels as proxy. • The Minimum Threshold for subsidence is defined as a cumulative decline equal to or greater than one foot since 2015, which represents current conditions and the SGMA start date. This corresponds to a rate of decline equal to or greater than 0.2 feet in any five-year period.
• The Minimum Thresholds for degradation of water quality address nitrate and total dissolved solids (TDS) for the entire Basin.
o The Minimum Threshold for nitrate is defined initially as the percentage of wells with concentrations exceeding the nitrate MCL (45 mg/L) based on current conditions (2015-2019).
o The Minimum Threshold for TDS is defined initially as the percentage of wells with concentrations exceeding the TDS value of 1,000 mg/L based on current conditions (2015-2019).
• The Minimum Threshold for depletion of interconnected surface water is the amount of depletion that occurs when the depth to the water along the southern edge of the Prado Wetlands is greater than 15 feet for a period exceeding one year.

ES-6 MONITORING NETWORK
The monitoring network for GSP implementation has been established to document groundwater and related surface conditions as relevant to the sustainability indicators, MTs, and MOs. The components of the monitoring network are built from existing programs and will be carried out by the Temescal GSA.

The Temescal GSA, Corona specifically, has actively engaged in assessment and improvement of its monitoring network. This process has been intensified as part of the GSP, given the need to identify data gaps and to assess uncertainty in setting and tracking sustainability criteria. Monitoring improvements such as adding or replacing monitoring infrastructure are part of GSP implementation and will be reviewed and updated for each five-year GSP update.

ES-7 PROJECTS AND MANAGEMENT ACTIONS
During the preparation of the GSP, the Temescal GSA identified five specific management actions (Actions) and three projects (Projects) to achieve the sustainability goal. The Actions are generally focused on data collection, storage and reporting of information necessary to monitor sustainability, and assessment of when Actions may be necessary (i.e., when MTs are approached or exceeded). The projects are generally designed to reduce uncertainty in areas where data gaps have been identified during development of the GSP. These projects and management actions are aimed at achieving sustainability goals and responding to changing conditions in the Basin. The projects and management actions are divided into three groups:
• Group 1 - Existing or established projects and management actions o Groundwater Treatment
Temescal Basin GSP ES-9
o Water Reclamation Facility (WRF) Percolation Ponds
o Water Level Quality Assurance and Quality Control (QA/QC) o Water Shortage Contingency Plans
o Water Conservation Program
o Participation in Integrated Regional Water Management Plans (IRWMP) o Western Riverside County Regional Wastewater Authority (WRCRWA) o Santa Ana Watershed Involvement
• Group 2 - Projects and management actions that have been or are under development
o Shallow Monitoring Well Installation
o Potable Reuse Feasibility Study
o Mountain Runoff Capture Feasibility Study
• Group 3 - Conceptual projects and management actions that can be considered in the future if any Group 2 projects fail to be implemented or additional intervention is required to achieve basin sustainability goals
o Groundwater Treatment
o Stormwater Capture, Treatment, and Recharge
o Santa Ana River Wastewater Discharge Coordination for Shallow The Projects and Actions will be implemented by a combination of existing resources from the three agencies within the Plan Area and contracted resources.

ES-8 IMPLEMENTATION
The official adoption of the GSP by the Temescal GSA will initiate Plan implementation. After submittal of the GSP to DWR, and during the DWR review period, the Temescal GSA will continue to communicate with stakeholders via the Corona’s website and begin implementing the projects and management actions described in this GSP. The Plan will be implemented to sustainably manage groundwater in the Basin under the authority of the Temescal GSA and its member agencies.

The Temescal GSA is required to submit an annual report to DWR by April 1st of each year following adoption of the GSP. The first annual report will be due in April of 2022. The Temescal GSA has committed to implementing the GSP upon adoption and completing the projects and management actions necessary to monitor and maintain sustainability within the first five years of initiation of the GSP.

Temescal Basin GSP 1-1

INTRODUCTION
The City of Corona (Corona) is actively managing the Temescal Subbasin (Basin) of the Upper Santa Ana River Groundwater Basin (Figure 1-1) in collaboration with the City of Norco (Norco) and Home Gardens County Water District (HGCWD). Corona, Norco, and HGCWD have previously participated in active management of water resources in the Basin. This management has included cooperation in preparing the 2008 Groundwater Management Plan (Todd and AKM 2008) and participation in regional planning and management. This historical experience provides a good foundation for continuation of groundwater management consistent with the Sustainable Groundwater Management Act (SGMA).

Wishing to provide a framework for cooperative groundwater management and SGMA compliance Corona, Norco, and HGCWD executed a Memorandum of Understanding (MOU) in March 2017 (Appendix A) establishing the Temescal Basin Groundwater Sustainability Agency (Temescal GSA). In August 2017, the Temescal GSA became the GSA for the Basin by submitting a formation notice to the California Department of Water Resources (DWR). This notice included publication of the MOU and each individual party’s resolutions to become a GSA to DWR through the SGMA web portal. In the MOU, Corona has accepted the primary responsibility to develop a GSP for the Basin, to submit the GSP to DWR, and to prepare Annual Reports and GSP updates thereafter. While Corona is leading this effort, the GSP will be developed jointly among the three agencies, with coordinated implementation toward sustainable management.

The GSP reflects the rigorous, systematic process through which the Temescal GSA will manage the Basin. Figure 1-1 shows the Plan Area for this GSP, which encompasses the entire Basin.

Sustainable management of the Temescal Basin is critical to local water supply reliability.

The three local agencies (both individually and jointly) in the Temescal GSA have developed water supply portfolios including imported water, groundwater from multiple local basins, and reclaimed water for landscape irrigation. Water conservation measures also have been implemented (as documented in the recent Corona and Norco Urban Water Management Plans (Michael Baker 2021, Norco 2021)), providing an important tool for responding to water shortages. Local agencies are active in regional water management and recognize that local groundwater is a primary source of supply and needs to be reliable. The Temescal Basin area historically has experienced significant land use changes—shifting from agricultural to urban land uses—and subsequent water demand and supply changes. This transition was achieved in part with reliance on local groundwater. In fact, the Corona Groundwater Management Plan indicated that overdraft conditions occurred in the Temescal Basin during the last three years of the 1990 to 2004 period as pumping increased.

While conditions subsequently improved, this illustrates that overdraft can occur. Concerns about water supply reliability persist, given the uncertainties of imported water and climate change. Moreover, groundwater quality generally is poor; in fact, sustainable groundwater use is dependent on treatment at the Temescal Desalter. SGMA and the GSP process provide an important set of tools for Corona and the Temescal GSA partners to address these conditions and plan for water supply reliability into the future.

Temescal Basin GSP 1-2

1.1. PURPOSE OF THE GROUNDWATER SUSTAINABILITY PLAN
The purpose of this GSP is to assess water resource and land use conditions within the Basin, through an open and collaborative process, and to implement management activities to achieve (or maintain) long-term groundwater sustainability as defined by SGMA.

The GSP assesses sustainability related to each of the six SGMA defined sustainability criteria listed below:
• Lowering Groundwater Levels
• Reduction of Groundwater Storage
• Seawater Intrusion
• Degraded Water Quality
• Land Subsidence
• Surface Water Depletion.

The GSP presents conditions in the Basin relevant to each of these categories, defines thresholds for maintaining sustainability, outlines groundwater monitoring protocols, and management actions and projects designed to improve monitoring capabilities and/or to protect and enhance groundwater conditions. The GSP also includes a schedule and cost estimate for GSP implementation. Each element of the GSP is designed to promote Basin health and achieve and maintain the sustainability goal established for the Basin by the GSA.

1.2. SUSTAINABILITY GOAL
The sustainability goal is to sustain groundwater resources for the current and future beneficial uses of the Basin in a manner that is adaptive and responsive to the following objectives:
• Provide a long-term, reliable, and efficient groundwater supply for municipal, industrial, and other uses
• Provide reliable storage for water supply resilience during droughts and shortages • Protect groundwater quality
• Support beneficial uses of interconnected surface waters, and • Support integrated and cooperative water resource management.

1.3. AGENCY INFORMATION
The GSA agencies collaborated on preparation of this GSP, as described in the March 2017 MOU between the agencies. The City of Corona, City of Norco, and HGCWD each passed resolutions to authorize the MOU to establish the GSA:
• City of Corona - On March 15, 2017, Corona held a public hearing to determine whether to become a GSA, and adopted Resolution No. 2017-013, electing to jointly become a GSA with Norco and HGCWD.
• Norco - On March 15, 2017, Norco held a public hearing to determine whether to become a GSA, and adopted Resolution No. 2017-12, electing to jointly become a GSA with Corona and HGCWD.

Temescal Basin GSP 1-3
• HGCWD - On March 23, 2017, HGCWD held a public hearing to determine whether to become a GSA, and, by minute action, elected to jointly become a GSA with Corona and Norco.

On May 10, 2017, Temescal GSA submitted to DWR a Notice of Decision to Become a Groundwater Sustainability Agency, along with required information including a boundary map of the GSA and a list of interested parties. After the 90-day review period, on August 8, 2017, Temescal GSA became the groundwater sustainability agency for the Basin.

As required by GSP Regulations §354.6 and SGMA §10723.8, the Notices of Decision to become a Groundwater Sustainability Agency are included in Appendix B. These each include the resolution, list of interested parties, and boundary map.

The point of contact for the Temescal GSA is:

Katie Hockett, Assistant General Manager
City of Corona Department of Water and Power
Temescal Basin GSA
755 Corporation Yard Way Corona, CA 92880
(951) 279-3601
[email protected]

1.4. GROUNDWATER SUSTAINABILITY AGENCY INFORMATION
As described above, the Temescal GSA was formed through a MOU between Corona, Norco, and HGCWD to act as the GSA for the Basin (Temescal Subbasin of the Upper Santa Ana Valley Basin, Basin Number 8-002.09), which is a DWR-designated medium priority basin.

The Temescal GSA is dedicated to participating in the collective goal of reaching groundwater sustainability in California.

Corona, Norco, and HGCWD have relied on groundwater from the Basin for municipal use for decades. In 2008, Corona adopted a Groundwater Management Plan that covers the entire Basin.

1.4.1. Decision Making
As detailed in the MOU, decisions in by the Temescal GSA are reached by unanimous consent of the parties; however, if unanimous consent is not possible, a majority vote of the three agencies rules.

1.4.2. Roles and Responsibilities
The MOU also documents the responsibilities of the individual agencies, including:
• Corona shall have the primary responsibility to develop a GSP within the boundaries of the Temescal GSA and submit the GSP to DWR for review and evaluation.Corona shall also have the primary responsibility to prepare and submit the annual and five year reports to DWR pursuant to SGMA and DWR’s implementing regulations.

Temescal Basin GSP 1-4
• The parties will work jointly to fulfill the purpose of the MOU within the boundaries of the Temescal GSA.
• The parties will meet regularly to discuss SGMA, GSP development, and implementation activities, assignments, and ongoing work progress. • The parties may form committees as necessary from time to time to discuss issues that impact the Temescal GSA.
• Corona is responsible for implementing the GSP in areas of the Temescal GSA that are within Corona’s service area boundaries and within Corona’s sphere of influence.
• Norco is responsible for implementing the GSP in areas of the Temescal GSA that are within Norco’s service area boundaries.
• HGCWD is responsible for implementing the GSP in areas of the Temescal GSA that are within HGCWD’s service area boundaries.

1.4.3. Legal Authority of the GSA
The GSA has authority to develop a GSP and implement SGMA in the Temescal Basin. SGMA specifies additional enabling powers; for example, GSAs may choose to adopt standards for measuring and reporting water use, develop and implement metering, and manage extraction from individual wells.

Corona’s Authority. Corona is a local agency qualified to become a GSA because Corona manages water, has a water supply, and has land use responsibilities over a portion of the Basin.

Norco’s Authority. Norco is also a local agency qualified to become a GSA because Norco manages water, has a water supply, and has land use responsibilities over a portion of the Basin.

HGCWD’s Authority. HGCWD is also a local agency qualified to become a GSA because HGCWD is a county water district formed and operating pursuant to and in accordance with Division 12 of the California Water Code that manages water, has a water supply and overlies a portion of the Basin.

Those portions of the Basin outside of these service areas are not within the area of any other proposed GSA. While the service areas of Corona, Norco, and HGCWD do not cover the entire Basin, these agencies do propose to serve as the GSA for the entire Basin. The three agencies in the GSA are coordinating with Riverside County Flood Control and Water Conservation District (RCFCWCD) for these currently unmanaged areas. Specifically, the RCFCWCD recognized the ongoing efforts for this GSA and offered to participate in any advisory or stakeholder committee formed by the GSA.

1.4.4. GSP Development Costs and Funding Sources
In November 2017, the City of Corona applied for a Sustainable Groundwater Management Planning (SGMP) Grant to fund preparation of this GSP. In April 2018, DWR awarded the City of Corona with full funding of $732,338.

Temescal Basin GSP 1-5
Each party will be financially responsible for collecting data or information from within that party’s service area that is required to be provided for development of the GSP. Norco and HGCWD will not incur any financial expense related to development of the GSP and submittal of the GSP to the DWR.

Implementation costs include costs to continue monitoring as described in Chapter 7, implement management actions and projects as described in Chapter 8, and complete annual reports and periodic GSP evaluation and updates as required by SGMA. As summarized in Chapter 9, total annual costs (2021 dollars) are estimated at approximately $100,000 per year and single occurrence costs for projects and management actions anticipated to occur in the first five years of GSP implementation and the first periodic GSP evaluation and update total approximately $515,000 to $575,000 (2021 dollars).

The funding method for operating expenses and GSP implementation costs is by contributions by GSA member agencies (Corona, Norco, and HGCWD). This is the same mechanism utilized to fund development of the GSP (with significant supplemental contribution though California Proposition 1 Grant funding). Corona will be responsible for most of the ongoing implementation costs, which are within budget projections for the next several years. Funding for planning and implementation of some projects and management actions may be achieved with local, state, and federal sources. The local agencies track opportunities for outside financing (grants or loans) from state water programs and federal infrastructure funding. For local financing, the agencies update their financial plans and rates as needed.

1.5. GSP ORGANIZATION
This GSP is organized generally to follow the GSP Annotated Outline provided by DWR as one of its Guidance Documents (DWR 2016a). Major sections include:
• Executive Summary
• Chapter 1 – Introduction, purpose of the GSP, sustainability goal, agency information, and GSP organization.
• Chapter 2 – Plan Area description, water use sectors, water supply sources, water resources monitoring and management programs, current general plans, and other GSP elements.
• Chapter 3 – Hydrogeologic Conceptual Model, description of the physical basin setting including surface water features, soils, geologic setting, faults, and aquifers, defined basin bottom, recharge and discharge areas, and cross sections. • Chapter 4 – Current and Historical Groundwater Conditions, discussion of groundwater elevations, land subsidence, groundwater quality and current monitoring, constituents of concern regarding water quality, interconnection of surface water and groundwater and the effects on groundwater dependent ecosystems (GDEs).
• Chapter 5 – Water Budget, discussion of the water budget, groundwater model, surface water and groundwater balance, change in groundwater storage, and estimate of sustainable yield.

Temescal Basin GSP 1-6
• Chapter 6 – Sustainable Management Criteria, sustainability goal and sustainability criteria for the six undesirable results.
• Chapter 7 – Monitoring Network, discussion of the monitoring that will continue to assess sustainability in the future.
• Chapter 8 – Projects and Management Actions, descriptions of projects and management actions for the Basin.
• Chapter 9 – Implementation Plan, estimate of GSP implementation costs, schedule, and plan for annual reporting and periodic evaluations. • Chapter 10 – References
A Preparation Checklist providing further organizational guidance to the GSP content requirements is provided in Table 1-1 and the GSP Elements Guide detailing GSP content in comparison to SGMA articles is included in Appendix C.