Water Stress and a Changing San Joaquin Valley Technical Appendices
CONTENTS Technical Appendix A: The San Joaquin Valley’s Water Balance 3 Brad Arnold and Alvar Escriva-Bou
Technical Appendix B: The San Joaquin Valley’s Economic Trends, Agricultural and Rural Community Characteristics, and Institutions 26 Jelena Jezdimirovic, Ellen Hanak, Brian Gray, Sarge Green, Josué Medellín-Azuara
Technical Appendix C: Native Species in the San Joaquin Valley: Drivers of Water and Land-use Regulation 41 Nathaniel Seavy and Peter Moyle
Supported with funding from the S. D. Bechtel, Jr. Foundation, the TomKat Foundation, and the US Environmental Protection Agency
This publication was developed with partial support from Assistance Agreement No.83586701 awarded by the US Environmental Protection Agency to the Public Policy Institute of California. It has not been formally reviewed by EPA. The views expressed in this document are solely those of the authors and do not necessarily reflect those of the agency. EPA does not endorse any products or commercial services mentioned in this publication.
Water Stress and a Changing San Joaquin Valley Technical Appendix A: The San Joaquin Valley’s Water Balance CONTENTS Figure A1 5 FIgure A2 7 FIgure A3 7 FIgure A4 8 FIgure A5 9 FIgure A6 10 FIgure A7 11 FIgure A8 12 FIgure A9 12 FIgure A10 13 FIgure A11 13 FIgure A12 15 FIgure A13 16 FIgure A14 16 FIgure A15 18 Figure A16 19 Table A1 20 FIgure A17 21 FIgure A18 22 FIgure A19 22 FIgure A20 23 FIgure A21 24
Brad Arnold and Alvar Escriva-Bou
Supported with funding from the S. D. Bechtel, Jr. Foundation, the TomKat Foundation, and the US Environmental Protection Agency
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 3
Assessing the Water Balance of the San Joaquin Valley
Objective This appendix provides information on data sources and methods used to assess the annual water balances in the San Joaquin Valley for 1986–2015.1 A water balance is an accounting statement that estimates water inflows (including precipitation and other water flowing into the area), outflows (including net or consumptive water used locally and water flowing out of the area),2 and changes in water stored in surface reservoirs and aquifers. As with any mass balance, the sum of inflows, outflows, and changes in storage has to be zero every year. By presenting inputs and outputs in an understandable way—and accounting for their variability—a water balance depicts the water uses and availability in a region. Water balances also illustrate how change in a water system—such as new policies, new infrastructure, or climate change—affects water availability and the system’s ability to meet water demands. The water balance presented here is a high-level overview of major water sources and uses. For the San Joaquin Valley, a particular interest is understanding the extent of long-term groundwater overdraft, or long-term depletions of water stored in aquifers. This practice will need to end as water users implement the state’s 2014 Sustainable Groundwater Management Act. Ending overdraft can be achieved by augmenting other usable inflows and reducing net water use. Estimating regional water balances is challenging in California. Official estimates of flows and uses often are not available over a time period that is both sufficiently long and up-to-date for long-term planning purposes.3 In addition, many of the flows needed are not available in a comprehensive and consistent manner. In particular, groundwater withdrawals and use are not tracked in a comprehensive way within the valley, and there are no systematic, long-term estimates of net water use. For these reasons, water balance estimation requires numerous intermediate calculations and assumptions. In the following sections, we first define the region’s boundaries. We then present estimates of inflows, outflows, and changes in water stored. We then summarize the overall water balance for the valley and compare our results with other estimates for overlapping years. Despite the inherent uncertainties, we believe our estimates provide a good “big picture” representation of the valley’s water balance for the past three decades.
Definition of the Region’s Boundaries The San Joaquin Valley includes two hydrologic regions: the San Joaquin River Basin and the Tulare Lake Basin. The valley is bounded by the Sierra Nevada mountains to the east, the Tehachapi mountains to the south, and the Coastal Range to the west. North of the San Joaquin Valley is the Sacramento–San Joaquin River Delta, the
1 In this technical appendix we always refer to water years: the 12-month period between October 1st and September 30th of the following year. The water year is designated by the calendar year in which it ends and which includes 9 of the 12 months. 2 Gross water use is the total amount of water applied to fields for irrigation or used indoors. Net (or consumptive) water use is the portion consumed by people or plants, embodied in manufactured goods, evaporated into the air, or discharged into saline water bodies or groundwater basins, where the water is not reusable without significant (and costly) treatment. Net water use excludes “return flows”—the portion of gross water use that returns to rivers, streams, or aquifers after use and is available for reuse. Return flows mainly come from irrigation water not consumed by crops and urban wastewater discharges. Because they are available for reuse, return flows are not considered a use in the water balance. 3 As described below, the Department of Water Resources’ (DWR) California Water Plan Update (Bulletin 160-13) provides estimates for 1998–2010; these estimates are problematic for key measures including groundwater overdraft. DWR’s C2VSim model has long-term estimates of water balances of surface water and groundwater for the region, but they only go through 2009. In both cases, these estimates stop before the onset of the severe drought in 2012, which has seen record levels of groundwater pumping.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 4
terminus of the San Joaquin River for water entering San Francisco Bay. The southern valley floor consists of low alluvial plains and fans, overflow lands, and old terminal lake beds. We calculate the water balance for the two regions combined—the commonly accepted definition of the greater San Joaquin Valley. Together, these two regions have a clear physical limit as an external boundary—the Sierra Nevada in the east, the Tehachapi Mountains in the south, the Coastal Range in the west, and the Delta in the North—with considerable internal hydrological connectivity. Flows from the San Joaquin River are conveyed to the Tulare Lake region through the Central Valley Project’s (CVP) Friant–Kern canal; flows from the Kings River in the Tulare basin run to the San Joaquin River during flood periods; both hydrologic regions receive water imported from Northern California through the Delta; and there is also significant joint water management and water trading across the combined region, using local, state, and federal infrastructure. To assess the water balance, we focus on the valley floor. Most water available in the San Joaquin Valley is either native to the Central and Southern Sierra Nevada or imported from the Sacramento hydrologic region through the Delta. The Valley floor is where most net or consumptive uses occur—especially from irrigated agriculture, but also from evapotranspiration from urban and environmental uses, and natural landscapes. The objective is to assess the annual net balance of inflows, outflows, and changes in water stored in surface reservoirs and aquifers. We define the Valley floor as the intersection of the Department of Water Resources (DWR) Planning Areas 602, 603, 606, 607, 608, 609, 702, 703, 704, 705, 706, 708, 709 and 7010 (Figure A1).
FIGURE A1 San Joaquin River and Tulare Lake watersheds
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Inflows Four types of water inflows are considered here: flows into the valley from local watersheds (including the Central and Southern Sierra Nevada and the Western Costal range), direct diversions from the Delta, water from net precipitation on the valley floor, and water imported from other regions—especially through the Sacramento– San Joaquin Delta, but also much smaller imports through the Folsom South Canal. These inflows can be either used the same year or stored in surface reservoirs or aquifers for later use. Conversely, some of the water used can be obtained from withdrawals from surface and groundwater storage.
Inflows from local watersheds To assess inflows into the valley floor from local watersheds we obtained estimates of “full natural” or “unimpaired” flows for the main rivers and creeks in the region.4 We obtained full natural flows (monthly volume) for the period of study from California Data Exchange Center (CDEC) for the following local watersheds (initials in parentheses are used to designate CDEC stations): . San Joaquin River hydrologic region o San Joaquin River – Friant Dam (SJF) o Merced River – Near Merced Falls (MRC) o Tuolumne River – La Grange Dam (TLG) o Stanislaus River – Goodwin (SNS) o Mokelumne River – Mokelumne Hill (MKM) o Cosumnes River – Michigan Bar (CSN) . Tulare Lake Basin hydrologic region o Kings River – Pine Flat Dam (KGF). o Kaweah River – Terminus Dam (KWT) o Tule River – Success Dam (SCC) o Kern River – Bakersfield (KRB) For some minor local watersheds in the San Joaquin River hydrologic region, where CDEC data were insufficient or inconsistent, we used 1986–2003 data from DWR (2007). We estimated the data after 2003 calibrating a simplified rainfall-runoff model that mimics the runoff response to rainfall in the gaged catchments. The catchments are: . Fresno River . Chowchilla River . Calaveras River . San Joaquin Valley East Side and West Side Minor Flows Figure A2 shows total annual inflow volumes from each watershed. California’s climate has pronounced annual variability, with substantial droughts—1987–92 and 2012–15—and wet periods—1995–98. Although there are inflows from 15 local watersheds, 5 rivers account for nearly 70 percent of the total average: Tuolumne (19%), San Joaquin (18%), Stanislaus (11%), Kings (11%) and Merced (10%).
4 Unimpaired flow is the natural runoff of a watershed in the absence of storage regulation and stream diversions. Full natural flow is the natural runoff of a watershed that would have occurred prior to human influences on the watershed, such as storage or diversions, but also land use changes. In this report we used full natural flows from CDEC stations where available, and unimpaired flows from DWR (2007) for the remaining watersheds.
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FIGURE A2 Inflows from local watersheds SJ Westside Minor SJ Eastside Minor Cosumnes River Mokelumne River Calaveras River Stanislaus River Tuolumne River Merced River 25,000 Chowchilla River Fresno River San Joaquin River Kings River Kaweah River Tule River Kern River
20,000
15,000
10,000 Local Local Inflows [TAF]
5,000
0 1986 1987 1988 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
Direct Delta diversions Central and southern Delta agricultural lands—included in the San Joaquin Valley floor—use water diverted directly from the Delta. Most of this water flows naturally from the Sacramento River and some from the San Joaquin River and other Delta tributaries, and it is not imported through the CVP or State Water Project (SWP) pumps. To account for this inflow, we assume that all the agricultural water use in the portion of the Delta that is included in the San Joaquin Valley floor is directly diverted from the Delta. Therefore these inflows can be estimated as the net or consumptive use of these agricultural lands. The methods to obtain net or consumptive water use are described in detail in a section below. To obtain the direct Delta diversions we use the same methodology for the area of the Delta that is in the San Joaquin Valley floor. The estimated annual diversions average roughly 750 thousand acre feet (taf) per year (Figure A3).
FIGURE A3 Direct Delta diversions
1,200 1,000 800 600 TAF 400 200 0 1986 1987 1988 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
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Net valley floor precipitation Total monthly precipitation on the valley floor has been obtained by clipping the gridded datasets from the PRISM Climate Group, Oregon State University, using a GIS layer of the study area. We assume that 15 percent of total monthly precipitation becomes net precipitation—the precipitation that does not evaporate and remains in the valley, where it is used by plants, flows into streams, or percolates to an aquifer. This estimate is based on the water balances from DWR’s California Water Plan (DWR 2013) for the entire Central Valley, and in the Central Valley water balance of C2VSim model (Brush et al. 2013). Relative to inflow from the Sierra (shown in Figure A2), net precipitation on the valley floor is less variable across dry and wet years because precipitation is more variable in the upper watershed (Figure A4).
FIGURE A4 Net precipitation on the valley floor
2,500
2,000
1,500 TAF 1,000
500
0 1986 1987 1988 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
Imports from other regions Water is imported into the valley from Northern California through pumps in the south Delta. A small volume is also imported through the Folsom South Canal.
Delta imports Delta imports are primarily from the Sacramento River with a small share from the San Joaquin River. These sources mix as they enter the Delta. Daily data for Delta imports from SWP facilities (Banks Pumping Plant or Clifton Court Intake), the CVP C.W. “Bill” Jones Pumping Plant at Tracy, and the Contra Costa Canal are obtained from Dayflow—a computer program designed to estimate daily average Delta outflows (DWR 2016).5, 6
Imports through the Folsom South Canal The Folsom South Canal imports a small volume of water from the American River into the northeastern side of the San Joaquin Valley. Data on water imported through the South Folsom Canal is obtained from the US Bureau of Reclamation Central Valley Operations Annual Delivery Reports (Table 21).
5 Note that CVP deliveries under the Friant Division are not included in these totals—this water is diverted from the San Joaquin River at Millerton Lake and diverted to the Friant-Kern Canal, which delivers water to users on the east side of the Tulare Basin. For the purposes of this regional water balance, these are considered local flows. 6 Note that Contra Costa Canal imports are included because the pumps are inside the San Joaquin Valley floor, but as the Contra Costa Water District is entirely out of the valley floor, these imports are later considered exports to the Bay Area.
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Figure A5 shows annual imports from the CVP and SWP pumps in the south Delta (Jones and Banks, respectively), the Contra Costa Canal, and Folsom South Canal.7 Total imports averaged 4.9 million acre-feet (maf) per year (53% from SWP and 47% from CVP), but in dry years imports from the Delta fall below 2 maf, as occurred in 2015. Imports through the South Folsom Canal averaged around 26,000 acre-feet/year.
FIGURE A5 Imports from other regions
Folsom South Canal Contra Costa Canal CVP pumps SWP pumps 7,000
6,000
5,000
4,000
3,000
Delta Imports [TAF] 2,000
1,000
0
1986 1987 1988 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
Outflows Four types of water outflows are considered: consumptive water use from evapotranspiration (water consumed by plants within the valley, and other evaporation to the atmosphere from the valley floor), San Joaquin Valley outflows to the Delta, exports from San Joaquin River tributaries to Bay Area water users, and exports of imported water that enters the valley.8
Consumptive water use Similar to precipitation, monthly consumptive water use was obtained by clipping evapotranspiration gridded datasets from the operational Simplified Surface Energy Balance model (Senay et al. 2013) using a GIS layer (Figure A6). This dataset provides high-resolution estimates of evapotranspiration, but only covers from 2000 to the present. To obtain earlier values, we employed multiple regression analysis, using temperature, precipitation, and potential evapotranspiration from crops, as independent variables (Figure A7).
7 Note that the CVP and SWP pumps and related conveyance infrastructure sometimes move water besides CVP and SWP project deliveries. This includes water transfers between parties located to the north and east of the Delta and those in the south and west of the Delta. 8 This may slightly understate total net water use insofar as it does not include water embodied in manufactured goods produced in the valley.
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FIGURE A6 Actual monthly evapotranspiration on the valley floor in water year 2001
SOURCE: Actual evapotranspiration obtained from the Simplified Surface Energy Balance (SSEBop) Model (Senay et al. 2013). NOTE: Maps show the San Joaquin Valley’s actual evapotranspiration (in millimeters) at a 1 km resolution using the same scale for each month in water year 2001.
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FIGURE A7 Evapotranspiration in the valley floor estimated by the SSEBop model for available years and predicted using multiple regression analysis for the entire period
Actual evapotranspiration estimated by SSEBop model Predicted evapotranspiration using multiple 20,000 regression 18,000 16,000 14,000 12,000 10,000 8,000 6,000 Evapotranspiration [TAF] Evapotranspiration 4,000 2,000 0 1986 1987 1988 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
NOTES: The values show the sum over the water year of the actual evapotranspiration in the valley floor. The actual evapotranspiration for the years 2001–15 is obtained from the SSEBop model (Senay et al. 2013) and the predicted evapotranspiration for the entire period is obtained from a multiple regression analysis using temperature, precipitation, and potential evapotranspiration from crops, as independent variables.
This approach enables us to obtain estimates of total evapotranspiration on the valley floor, but it does not enable us to assess consumptive uses for different end users (i.e., agriculture, urban, environmental, and natural landscapes). The California Water Plan (DWR, 2013) estimates consumptive uses for each hydrologic region by end use from 1998 to 2010.9 From this dataset we obtain the average share of consumptive uses by end use, and then apply these shares to the estimates of evapotranspiration for the entire 30-year period (Figure A8). The consumptive use of cities, managed wetland areas, and natural landscapes is quite small as a share of the total (4%, 2% and 5% respectively), making agriculture the predominant consumptive water user (89%) (Figure A9).
9 As discussed below, the California Water Plan’s consumptive use estimates differ significantly from the evapotranspiration estimates obtained by the method described above between wet and dry years, but the annual average for 1998–2010 is very close, at roughly 13.7 million acre-feet.
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FIGURE A8 Annual evapotranspiration by end use
20,000 Agriculture Urban Wetlands Other 18,000 16,000 14,000 12,000 10,000 8,000 6,000
Evapotranspiration [TAF] Evapotranspiration 4,000 2,000 0 1986 1987 1988 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
FIGURE A9 Average evapotranspiration by end use, 1986–2015
Cities 4% Wetlands Farms 2% 89% Other evaporation 5%
NOTES: Other evaporation is an estimate of evapotranspiration from natural landscapes (not farms or irrigated landscapes in urban areas). Total evapotranspiration averages 13.3 maf over the 1986–2015 period, with evapotranspiration from farms averaging 11.9 maf, from cities 0.5 maf, from wetlands 0.2, and 0.7 maf from natural landscapes. Gross or applied water use on farms, cities, and managed wetlands averaged 18.8 maf, with 90% on farms, 7% in cities, and 3% on managed wetlands.
San Joaquin Valley outflows Outflows for San Joaquin River and other minor Delta tributaries (Figure A10) were obtained from Dayflow calculations. These flows are reported as Delta inflows from the San Joaquin River (measured at the Vernalis gage) and eastern Delta inflow (including the Cosumnes and Mokelumne rivers and other minor creeks).10 San Joaquin Valley maximum outflows are determined by the ability to capture them for later use in upstream reservoirs in wet years, whereas minimum outflows are required by environmental and water quality regulations in the river and the Delta.
10 San Joaquin Valley outflows that are subsequently recaptured as Delta imports or direct Delta diversions are counted as inflows to the region, and included in the Delta import measures presented below.
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FIGURE A10 San Joaquin Valley outflows
12,000
10,000
8,000
6,000 TAF
4,000
2,000
0 1986 1987 1988 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
Exports from San Joaquin River tributaries The San Joaquin Valley exports several hundred thousand acre-feet of water annually from local sources to the San Francisco Bay Area (Figure A11). Water from the Tuolumne River is stored in the Hetch Hetchy Reservoir and then conveyed to the San Francisco Public Utilities Commission (SFPUC) service area. Water from the Mokelumne River is stored in the Camanche Reservoir and transported to the East Bay Municipal Utility District (EBMUD) service area.
FIGURE A11 Water exports from San Joaquin River tributaries
SF Bay El DorradoDorado IDID 500 450 400 350 300 250 TAF 200 150 100 50 0 1986 1987 1988 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
Data from 1998–2010 was obtained from the California Water Plan (DWR, 2013) (imports to the San Francisco Bay Hydrologic Region). The remaining years have been estimated with a regression analysis, using the unimpaired flows of the rivers for the entire series as an independent variable, and extrapolating the shares of the
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 13
diverted data with respect to the unimpaired flows for the 1998–2010 dataset. The average annual exports for 1986-2015 are 0.38 maf/year. Figure A11 also includes a small volume of exports to the El Dorado Irrigation District in the Sacramento River hydrologic region. This water is diverted from Jenkinson Lake in the Sly Park Creek, a tributary of the Cosumnes River, and averages 18,000 af per year. Diversion data is obtained from CDEC (station CCN). Note the low variability of water exports from the San Joaquin Valley tributaries compared with the high variability of inflows in these tributaries shown in Figure A2.
Exports of Delta imports Some Delta imports that enter the valley through the CVP and SWP pumps are then delivered to the San Francisco Bay Area, the Central Coast, and Southern California (Figure A12).
. Exports to the San Francisco Bay Area: This includes water from two points of diversion: (1) through the South Bay Aqueduct from the South Bay Pumping Plant (data are from the SWP Annual Reports of Operations), and (2) through the Contra Costa Canal (data are from USBR Central Valley Project Annual Reports of Operations, Table 21). 1986–2015 average: 0.24 maf/year. . Exports to the Central Coast: This includes water from two points of diversion: (1) through Las Perillas Pumping Plant on the California Aqueduct (from SWP Annual Reports of Ops: Table 1); and (2) through the Pacheco Tunnel.11 1986–2015 average: 0.22 maf/year. . Exports to Southern California: This includes water delivered through the A.D. Edmonston Pumping Plant on the California Aqueduct (from DWR SWP Annual Reports of Ops: Table 1 Totals). 1986–2015 average: 1.2 maf/year.
11 San Luis Reservoir Operations from DWR SWP Annual Reports of Operations: post-2000 Reports, Table 15 Annual San Luis Joint-Use Facility Total, and pre-2000 Reports, Table 13 San Luis Reservoir Operations Total Outflow (Pacheco Tunnel). 2015 data obtained from Santa Clara Valley Water District urban water supply data. Some water going through the Pacheco Tunnel goes to the Santa Clara Valley Water District and could be included in the exports to the San Francisco Bay Area. As we do not have access to sufficient data to separate the flows that remain in the Central Coast and those that go to the San Francisco Bay Area, we include them as exports to the Central Coast.
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FIGURE A12 Exports of Delta imports
3,000 Southern California Central Coast SF Bay
2,500
2,000
1,500 TAF
1,000
500
0 1986 1987 1988 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 Changes in storage Two main storage types are considered: surface reservoirs and water stored in aquifers. Data exist for water stored in surface reservoirs. Changes in aquifer storage are estimated as the volume required to close the water balance for the valley.
Changes in reservoir storage From CDEC, we obtained data for monthly storage for 13 major reservoirs in the San Joaquin Valley: New Melones (NML), Don Pedro (DNP), Lake McClure (EXC), Pine Flat (PNF), Lake Isabella (ISB), Success Dam (SCC), Kaweah Lake (TRM), Millerton Lake (MIL), Eastman Lake (BUC), Mariposa Reservoir (MAR), Bear Reservoir (BAR), New Hogan Lake (NHG), and Camanche Reservoir (CMN). Figure A13 shows monthly storage for these reservoirs. Annual storage change is the water stored at the beginning of the prior water year minus the storage at the beginning of a new water year (October 1). The reliability of data for the 1986 and 1987 water years is lower, because there were more gaps in the series.12
12 As discussed below, this could affect the results of the water balance for these years.
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FIGURE A13 Water stored in the 13 major reservoirs of the San Joaquin Valley between October 1987 and September 2015 (monthly)
ISB SCC TRM PNF MIL BUC MAR 9,000 BAR EXC DNP NML NHG CMN
8,000
7,000
6,000
5,000 TAF 4,000
3,000
2,000
1,000
0 Oct-87 Oct-88 Oct-89 Oct-90 Oct-91 Oct-92 Oct-93 Oct-94 Oct-95 Oct-96 Oct-97 Oct-98 Oct-99 Oct-00 Oct-01 Oct-02 Oct-03 Oct-04 Oct-05 Oct-06 Oct-07 Oct-08 Oct-09 Oct-10 Oct-11 Oct-12 Oct-13 Oct-14 Oct-15
To include water stored in other minor reservoirs, we obtained the change in total water stored from the California Water Plan (DWR 2013) for the two hydrologic regions and extrapolated the other years using a linear relationship between total changes in storage and changes in the storage in the 13 major reservoirs (Figure A14).
FIGURE A14 Linear relationship between total water stored at the beginning of the water year (WY) in the San Joaquin Valley and the valley’s 13 major reservoirs
12,000
y = 1.4274x + 739.21 10,000 R² = 0.9746
8,000
6,000
4,000
2,000 from Californi Water Plan (TAF) Water Californi from
Storage at the beginning of WYof the beginning at the Storage 0 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 Storage at the beginning of the WY in the 13 major reservoirs from CDEC data (TAF)
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Total net changes in annual surface storage are shown in Figure A15b. The long-term average change in surface water stored is roughly zero.
Changes in water stored in aquifers Finally, we obtain the change in water stored in aquifers as the residual that closes the water balance for the valley. In short, the net available water supply (from inflow, precipitation, and changes in storage) must equal the net volume of water used within the valley (consumptive use) or exported. The mass balance equation can be formulated as:
=
+ ∆ 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴+ +
𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿 𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊ℎ𝑒𝑒𝑒𝑒𝑒𝑒 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑁𝑁𝑁𝑁𝑁𝑁 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝑟𝑟𝑡𝑡𝑡𝑡 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 𝑂𝑂𝑂𝑂ℎ𝑒𝑒𝑒𝑒 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 − Changes𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 in annual𝑈𝑈𝑈𝑈𝑈𝑈 − a𝑆𝑆quifer𝑆𝑆𝑆𝑆 𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂 storage− are𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 shown𝑓𝑓𝑓𝑓𝑓𝑓 below𝑓𝑓 𝑆𝑆𝑆𝑆 𝑅𝑅 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅in Figure𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 A15c.− As𝐸𝐸𝐸𝐸 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸discussed𝑜𝑜𝑜𝑜 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 below,𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼 these𝐼𝐼 − estimates∆ 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 are𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 in the neighborhood of estimates of groundwater depletion found by others. Long-term overdraft of San Joaquin Valley aquifers is roughly 1.8 maf/year.
San Joaquin Valley Water Balance Once all annual inflows, outflows, and changes in storage are estimated, the balance for each year is calculated (Figure A15). Although consumptive water use remains fairly constant (averaging more than 13 million acre feet over 1986–2015), inflows from local supplies13 and net imports into the Valley14 are highly variable depending on annual precipitation. The difference between annual water supply and consumptive use—shown in Figure A15a— is reflected in changes in surface storage (Figure A15b) and groundwater storage (Figure A15c). In wet years when annual supplies exceed consumptive use, there is net recharge. In other years, there are net withdrawals. This highlights that water storage is essential in managing water in the San Joaquin Valley because of the high variability in annual precipitation and between drought and wet cycles. Figure A15 shows that only a few very wet years increase water storage. Most years have a net withdrawal from surface and groundwater storage. Average change in surface storage is close to zero over the 1986–2015 period because all water that enters a reservoir has to get out sooner or later. However, on average 1.8 million acre feet per year have been withdrawn from aquifers over this period.15 Surface storage capacity is much more limited than underground storage capacity. Figure A15b shows that surface reservoirs help greatly in the first years of a drought, but if the drought persists and reservoir levels drop significantly, much more water is pumped from aquifers. This behavior has worsened in the past decade, when reduced Delta imports coincided with dry years—2007–09 and 2012–15—resulting in an average aquifer overdraft of 2.4 million acre feet per year during 2006–15 (Figure A15c).
Figure A16 shows a schematic representation of the average balance for the period 1986–2015, and Table A1 summarizes the net uses and water sources depicted in the figure.
13 Inflows from local supplies can be used directly as surface diversions but also indirectly by replenishing aquifers and pumped later as sustainable groundwater use. 14 Net imports into the valley are the total water imported from other regions minus the water that is exported to other regions. 15 As mentioned above, reservoir data for the years 1986 and 1987 had low reliability. This could explain why in 1986, a wet year, our model is not reporting an increase in reservoir storage, but a very large increase in water stored in aquifers.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 17
FIGURE A15 Components of the San Joaquin Valley’s annual water balance
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 18
FIGURE A16 Average water balance in the San Joaquin Valley, 1986–2015
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 19
TABLE A1 The San Joaquin Valley’s water balance (1986-2015)
Annual Average Volumes Uses and Sources (maf)
Net Uses (13.3)
Agriculture (11.9)
Cities (0.5)
Wetlands (0.2)
Evaporation (0.7)
Net Water Sources 13.3
Local supplies remaining in the SJ Valley 7.4
Local inflows from the Sierra 10.4
Precipitation in the valley Floor 0.9
San Joaquin River outflow (3.5)
SJV exports to Bay Area (0.4)
Delta imports remaining in the SJ Valley 3.3
Delta imports (total) 4.9
Delta imports to Bay Area (0.2)
Delta imports to Central Coast (0.2)
Delta imports to Southern California (1.2)
Direct Delta diversions 0.8
Groundwater overdraft 1.8
NOTES: Outflows from the region are shown in parentheses.
Figure A17 shows the average share of water sources in the San Joaquin Valley in different time periods. Local supplies are substantial, averaging 56 percent of the total over the past 30 years. These local supplies can be used directly as surface water and indirectly by replenishing aquifers and pumped later as sustainable groundwater use. The valley also relies significantly on imported water and groundwater overdraft. For the entire 30-year period, imports provided 25 percent of supplies, direct Delta diversions supplied 6 percent, and groundwater overdraft provided 13 percent. These shares have shifted over the second half of the period, marked by prolonged drought and reduced local and imported surface sources. From 2001 to 2015, local supplies were 54 percent of supplies, down from 58 percent in the first half of the period. Imports fell from 27 to 23 percent. And groundwater significantly increased, from 10 to 17 percent of total supplies.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 20
FIGURE A17 Average share of water sources in the San Joaquin Valley over different periods.
Panel A: Period 1986–2015 Panel B: Period 1986–2000 Panel C: Period 2001–2015 Local Local Supplies Local Supplies Supplies 56% 58% 54%
Direct Delta Direct Delta Direct Delta Diversions Diversions Diversions 6% 5% 6%
Imports Imports Imports 25% 27% 23%
Groundwater Groundwater Groundwater Overdraft Overdraft Overdraft 13% 10% 17%
NOTES: During the 1986–2015 period the total supplies were 13.2 maf, during the 1986–2000 period 13.7 maf, and during the 2001–15 period 12.2 maf. Local supplies include changes in reservoir storage. Carryover storage from the previous years contributed roughly 350 taf/year (3%) to local supplies from 2001–15 (Panel C). For the entire period from 1986–2015, carryover storage contributed about 150 taf/year (1%). It was negligible for 1986–2000.
Other trends in water sources The San Joaquin Valley receives the largest share of Delta imports. However, this share has declined over time, as Southern California’s share has increased (Figure A18). This shift reflects Southern California’s increased ability to take and store water under its long-standing State Water Project contracts, thanks to investments in new surface storage (e.g., construction of Diamond Valley Lake, expansion of San Diego’s San Vincente Dam) and increases in groundwater banking within Southern California and in Kern County. In addition, some San Joaquin Valley irrigation districts have sold project contracts to Southern California urban agencies on a permanent or long-term basis (Hanak and Stryjewski 2012).16 From 1986 to 2000, the San Joaquin Valley received an average of 72 percent of all Delta imports; that share fell to an average of 61 percent in 2001-2015. Meanwhile, Southern California’s share rose from 19 percent to 29 percent. On average, this represents a shift of about 0.5 maf/year. Deliveries to the San Francisco Bay Area and Central Coast remained fairly stable, with each receiving just under 5 percent.
16 From 1998 to 2009, San Joaquin Valley irrigation districts sold State Water Project contracts with a face value of 110,000 acre-feet to Southern California agencies; long-term transfer agreements for over 12,000 acre-feet were also negotiated. The average annual volume of water transferred through these agreements totaled 83,000 acre-feet from 2003 to 2011 (Hanak and Stryjewski 2012, appendix table B6c and B8). During the latest drought, deliveries were lower, commensurate with cuts in SWP deliveries. Southern California also made net withdrawals from Kern County groundwater banks in the 2001–15 period. San Joaquin Valley irrigation districts also permanently transferred 50,000 acre-feet of contracts to San Francisco Bay Area agencies, and agreed to long-term transfers of more than 13,000 acre-feet.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 21
FIGURE A18 Share of Delta imports by region
San Joaquin Valley Southern California SF Bay Central Coast 100% 90%
80%
70%
60%
50%
40%
30%
20% 10% 0%
1986 1987 1988 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
The largest surface water outflow from the valley is outflow from the San Joaquin River into the Delta. Figure A19 compares unimpaired flow—runoff that would have occurred without storage and human diversions and uses—and the actual outflow. The difference between unimpaired flow and actual flow in the San Joaquin River is water diverted and used consumptively in the basin.17 Over the past 30 years, outflow has averaged 61 percent of unimpaired San Joaquin River flows, and there has been no appreciable trend in this ratio.
FIGURE A19 Unimpaired and actual San Joaquin River outflows
16,000 SJR Unimpaired SJR Outflows
14,000
12,000
10,000
8,000
6,000 Annual flows [TAF] Annual 4,000
2,000
0 1986 1987 1988 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
17 Natural flows in the era before economic development in the valley would have been substantially lower than these unimpaired flows, because the extensive wetlands on the valley floor would have generated much more evapotranspiration than the remaining wetlands do today.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 22
Comparison with other water balance efforts Several other efforts have sought to develop water balances for the Central Valley’s hydrologic regions for some of the years examined here, using somewhat different approaches. The most comprehensive analyses for the Central Valley are: 1) the California Water Plan (DWR 2013); 2) the California Central Valley Groundwater- Surface Water Simulation Model (C2VSim); 3) the Central Valley Hydrologic Model (CVHM).
The California Water Plan (CWP) includes water balances by hydrologic region from 2001–10, with data extending back to 1998 on the webpage. We used CWP data—combining the San Joaquin River and Tulare Lake hydrologic regions—to develop many of our variables, as reported above. Although CWP data are comprehensive, they contain important gaps and inconsistencies. First, the balances omit estimates of natural groundwater recharge, so CWP’s estimates of groundwater overdraft are too high. Second, the CWP’s estimate of consumptive water use deviates considerably from actual evapotranspiration obtained using the SSEBop model (reported above). Figure A20 shows how the CWP underestimates evapotranspiration in wet years and overestimates it in dry years compared with the SSEBop model, although average evapotranspiration over the Valley is similar. As the approach that the CWP has used to estimate consumptive use is not explicit, we prefer to use the result of the SSEBop model.18
FIGURE A20 Comparison of consumptive use estimates from the California Water Plan water balances and the SSEBop model.
SSEBop 20,000 CA Water Plan 18,000
16,000
14,000
12,000
10,000 TAF 8,000
6,000
4,000
2,000
0 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
C2VSim is an integrated numerical model that simulates water movement through the linked land surface, groundwater and surface water flow systems in California’s Central Valley. The model contains monthly historical stream inflows, surface water diversions, precipitation, land use and crop acreages from October 1921 through September 2009. Groundwater pumping and changes in groundwater storage also can be obtained from the model. The data by hydrologic region is available for download from their database.
18 Evapotranspiration is a function of water availability in the soil and energy in the form of solar radiation. It therefore makes sense that in wet years, when there is more water available in the soils, evapotranspiration goes up, as the results of the SSEBop model show. Because soils are wetter in wet years, this often results in lower demand for irrigation—something reflected in the CWP water balance numbers for applied or gross farm water use. However, the CWP estimates also assume reductions in net water use in such years because they do not consider the contribution of soil moisture to plant ET.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 23
Figure A21 presents a comparison of net groundwater recharge for the three sources for which annual estimates are available—PPIC, C2VSim, and California Water Plan. Results of the C2VSim model and the PPIC estimates are similar for most years. In contrast, as anticipated, the California Water Plan balances substantially overestimate overdraft. (For 1998–2009, years for which estimates are available from all three sources, CWP estimates average annual overdraft of 4.5 maf, versus 1.4 maf for C2VSim and 1.7 maf for PPIC.) For the longer period during which both C2VSim and PPIC estimates are available (1986-2009), the annual averages from these two sources are both 1.5 million acre-feet.19
FIGURE A21 Comparison of changes in annual groundwater storage using the C2VSim model, the California Water Plan water balances, and the PPIC water balance
PPIC C2VSim CA Water Plan 8
6
4
2
0 MAF
-2
-4
-6
-8
-10 1986 1987 1988 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
Finally, the Central Valley Hydrologic Model (CVHM) is an extensive, detailed, three-dimensional (3D) computer model of the hydrologic system of the Central Valley (Faunt et al. 2016). The model simulates groundwater and surface-water flow, irrigated agriculture, subsidence, and other key processes in the Central Valley. From the last article published (Faunt et al., 2016) we estimate that cumulative overdraft in the entire Central Valley for the period 1986–2015 has been approximately 60.8 million acre feet. This suggests a Central Valley-wide average (which includes the Sacramento Valley plus the San Joaquin Valley) of 2 million acre feet per year—slightly higher than our estimate of 1.8 million acre-feet for the San Joaquin Valley alone. This also suggests relatively consistent results with our estimates of overdraft, given that most Central Valley overdraft occurs in the San Joaquin Valley. These comparisons make us fairly confident that our 30-year regional estimates of groundwater overdraft—the “balancing” element in our San Joaquin Valley’s water balance—are “in the ballpark.” Moreover, this exercise
19 Our estimate for 1986 differs substantially from C2VSim results. As discussed above, the surface storage data that we used for this year had many gaps. 1986 was a wet year, so it seems logical that surface storage should increase during this year. Our data are not showing this increase, so it may be that our estimation method overestimates groundwater recharge for this year, relative to surface storage.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 24 underscores the importance of improving estimates of key elements of the water balance for detailed planning purposes, including the development of local and regional groundwater sustainability plans. Although there is value in understanding the regional picture of water sources and uses, it will be essential to understand these balances at the sub-regional scale, where management actions and planning occur. As described in the main report, conditions vary considerably across the valley’s sub-regions, reflecting differential access to surface and groundwater supplies, and the extent of intensive crop production.
ACRONYMS C2VSim California Central Valley Groundwater–Surface Water Simulation Model CDEC California Data Exchange Center CVP Central Valley Project DWR Department of Water Resources EBMUD East Bay Municipal Utility District SFPUC San Francisco Public Utility Commission SWP State Water Project USBR United States Bureau of Reclamation
REFERENCES Brush, C.F., Dogrul, E.C., and Kadir, T.N. June 2013. Development and Calibration of the California Central Valley Groundwater– Surface Water Simulation Model (C2VSim). Version 3.02-CG. California Department of Water Resources (DWR), Bay-Delta Office. 2007. California Central Valley Unimpaired Flow Data, Fourth Edition. California Department of Water Resources (DWR). 2013. “California Water Plan, Update 2013.” Faunt, Claudia C., et al. “Water Availability and Land Subsidence in the Central Valley, California, USA.” Hydrogeology Journal 24.3 (2016): 675-684. Senay, G. B., Bohms, S., Singh, R. K., Gowda, P. H., Velpuri, N. M., Alemu, H., et al. (2013). “Operational Evapotranspiration Mapping Using Remote Sensing and Weather Datasets: A New Parameterization for the SSEB Approach.” Journal of the American Water Resources Association, 1–15.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 25 Water Stress and a Changing San Joaquin Valley
Technical Appendix B: The San Joaquin Valley’s Economic Trends, Agricultural and Rural Community Characteristics, and Institutions
CONTENTSFigure B1 28 Figure B2 28 Figure B3 29 Figure B4 30 Figure B5 31 Table B1 32 Figure B6 33 Table B2 34 Figure B7 35 Table B3 36 Figure B8 37 Table B4 38
Jelena Jezdimirovic, Ellen Hanak, Brian Gray, Sarge Green, Josué Medellín-Azuara
Supported with funding from the S. D. Bechtel, Jr. Foundation, the TomKat Foundation, and the US Environmental Protection Agency
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 26
The San Joaquin Valley’s Economic Trends, Agricultural and Rural Community Characteristics, and Institutions
This appendix provides supplemental information and data sources and methods used to describe economic trends, agricultural and rural community characteristics, and institutions, as summarized in the main report Water Stress and a Changing San Joaquin Valley.
Agriculture and the Valley Economy The San Joaquin Valley is a major supplier of fruits, nuts, dairy, and beef to national and international markets. But just how big is the agriculture’s share in the regional economy, and how has it evolved over time? To understand the current picture, we use estimates of gross domestic product (GDP), revenue, and employment. And to examine long-term trends, we look at income (the largest component of GDP) and employment.
A cross-sectional look at regional economy To estimate recent employment, revenues, and GDP, we used county-level IMPLAN model data for 2012 and 2014 for the eight San Joaquin Valley counties (Fresno, Kern, Kings, Madera, Merced, San Joaquin, Stanislaus, Tulare). We include both primary crop and animal production (including agricultural services) and food and beverage processing, a downstream activity closely related to farm production. The 2012 data provide a useful snapshot of economic activity prior to the onset of drought-related acreage reductions and a boom in prices for many commodities, including almonds, so we consider it more representative of recent conditions. The 2014 data (the most recent available at the time of writing) reflect some acreage reductions, but also very high prices for some commodities. Figure B1 compares employment, revenues, and GDP for agriculture and related food and beverage manufacturing in the San Joaquin Valley and California in 2012; it shows that agriculture has a much larger economic footprint in the Valley than in the state as a whole. (This share would be even larger if one included all the related economic activity in sectors such as transportation and farm inputs.) Figure B2 compares the same economic indicators in the Valley for 2012 and 2014. In 2014, the spike in commodity prices outweighed losses related to reductions in irrigated acreage, so both the volume and the share of agriculture in GDP grew. Prices dropped somewhat in 2015, leading some news outlets to confound price- and drought-related impacts on California agriculture (e.g., Lang 2016).
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 27
FIGURE B1 Agriculture is much more important to the valley’s economy than to California’s economy
30% San Joaquin Valley California 25% 13% 20% Crop and animal production
Food & beverage 15% 3% 5% processing 13% 10% 12% 10%
5% 3% 1% 1% 0% 2% 2% 1% Employment Revenue GDP Employment Revenue GDP
SOURCE: Author calculations using IMPLAN data for 2012. NOTES: Estimates shown are for direct effects, including support services to agriculture. Employment includes full-time, part-time, and seasonal jobs. For the San Joaquin Valley, total employment is 1,681,112; total revenue is $258 billion; total GDP is $138 billion. For California, total employment is 20,189,314; total revenue is $3,402 trillion; total GDP is $2,050 trillion.
FIGURE B2 High commodity prices in 2014 led to agricultural GDP gains in the valley despite acreage reductions
2014 2012 30% Food & beverage processing 25% (%) of total SJV
20% Crop and animal 13% 13% 4% production (%) of total SJV 15% 3% 4% 5% 10% 17%
13% 12% 13% 12% 5% 10%
0% Employment Revenues GDP Employment Revenues GDP
SOURCE: Author calculations using IMPLAN data for 2012 and 2014. NOTES: Estimates shown are for direct effects, including support services to agriculture. Employment includes full-time, part-time, and seasonal jobs. For 2012, total employment is 1,681,112; total revenue is $258 billion; total GDP is $138 billion. For 2014, total employment is 1,824,908; total revenue is $303 billion; total GDP is $165 billion.
Figure B3 provides comparable county-level data for 2012, and reveals some diversity within the region in the economic importance of farming. In three of the eight counties—Fresno, Kern, and San Joaquin—agriculture’s share of GDP is lower than for the valley as a whole (though still considerably larger than the statewide average). These three counties have the most populous urban centers in the valley—Fresno, Bakersfield, and Stockton—and the highest GDP numbers in absolute terms.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 28
All eight counties have a significant portion of crop and animal GDP from dairy and/or fruit and nut farming. This is consistent with the longer term trends of valley farmers switching to more permanent crops and dairy production (Figures 3 and 4 in the main report, respectively). Stanislaus County leads in food and beverage processing overall and in relative terms—driven mainly by a large poultry processing industry. In absolute terms, Fresno has the second highest food and beverage GDP—especially from fruit and vegetable canning and poultry processing—but this sector only accounts for 4 percent of county GDP, further highlighting the difference between rural and more urbanized counties in the valley. This divide is visible in employment as well—close to a quarter of total employment is related to agriculture in the more rural Kings, Madera, Merced, and Tulare counties.
FIGURE B3 Agriculture is an economic driver in the valley but with some variation across counties Employment (2012) Crop and animal production (%) of total 1% 4% Food & beverage 6% 8% processing 2% 3% 3% (%) of total 23% 6% 20% 16% 3% 12% 15% 13% 13% 7% 8%
Fresno Kern Kings Madera Merced San Stanislaus Tulare 8 county average Joaquin Revenues (2012)
31% 20% 17% 7% 11% 23% 13% 21% 11% 21% 5% 18% 21% 11% 8% 7% 8% 12%
Fresno Kern Kings Madera Merced San Stanislaus Tulare 8 county average Joaquin
GDP (2012)
7% 6% 2% 9%
4% 10% 5% 2% 19% 18% 19% 14% 4% 10% 9% 8% 7% 6% Fresno Kern Kings Madera Merced San Stanislaus Tulare 8 county average Joaquin SOURCE: Author calculation using IMPLAN data. NOTES: Estimates shown are for direct effects, including support services to agriculture. Employment includes full-time, part-time, and seasonal jobs.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 29
Trends in agricultural income and employment Over time—even with rapid population growth and urbanization—agriculture has maintained a strong economic presence in the regional economy. To examine longer-term economic trends, we use personal income (wages and proprietors) as a proxy for GDP, since long-term county GDP estimates are not available.20 Our primary source is the Regional Economic Accounts from the Bureau of Economic Analysis (BEA). In addition to being available for a long period (1970– 2015), these series have two other advantages: they include income from most proprietors and workers, and they provide estimates for the “agriculture services” sector—including farm contract labor which has been growing in importance as a share of total farm employment.21 Figure B4 shows the farm-related share of total valley income over time. This share has dropped since the 1970s and early 1980s, reflecting faster growth in other sectors. (Note also that the spikes during this period reflected international commodity price booms in the mid-1970s and 1979–1980.)22 But over the past 25 years, agriculture has broadly maintained its share of regional economic activity. From 2011 to 2015, farm-related income averaged 18 percent of regional income, comparable to the average in the late 1980s to early 1990s. It dipped to an average of 14 percent in the early 2000s, a period of lower commodity prices.
FIGURE B4 Farm-related share of regional income
30%
25%
20%
15%
10%
5%
0% 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014
Total Farm Income Total Farm-Related Income (including food and beverage processing)
SOURCE: Bureau of Economic Analysis (2016a). NOTE: Farm income includes income from crop and animal production and forestry, fishing, hunting, and related activities (agricultural services).
20 In addition to proprietor and wage income, GDP includes taxes and other income. In 2012, the shares of San Joaquin Valley GDP were: wage income (51%), proprietor income (11%), taxes (7%) and other income, including payments for rents, royalties, and dividends (30%). 21 While BEA datasets are comprehensive in scope, they do have some gaps. Sometimes (especially for small county industry sectors), BEA does not disclose sector level data for confidentiality purposes. Most of the income data we worked with was disclosed, including all direct farm and food and beverage processing. We encountered a few gaps in agriculture services, which we estimated in two ways. Where possible, we used linear interpolation (if a county had values for some years, but not others). Elsewhere, we used Quarterly Census of Employment and Wages (QCEW) data to calculate a ratio of agriculture services income to total income for a particular county and a year. We then applied that ratio to total income in the BEA series. 22 For a discussion of price fluctuations in this period, see Agricultural Commodity Price Spikes in the 1970s and 1990s: Valuable Lessons for Today (Peters et al. 2009).
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 30
For employment, we use the Regional Economic Accounts for farm employment and the Bureau of Labor Statistics Quarterly Census of Employment and Wages (QCEW) for food and beverage processing.23 Farm-related employment has grown modestly, from an average of roughly 215,000 in the mid-1970s to over 290,000 in 2015 (Figure B5a). Although it has declined over time as a share of total valley employment, its share has remained relatively stable for the past decade (Figure B5b).24
FIGURE B5 Farm-related jobs have grown but are a shrinking share of overall employment
A) Farm-related employment B) Farm-related share of employment
350,000 30%
300,000 25% 250,000 20% 200,000 15% 150,000 10% 100,000
50,000 5%
- 0% 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 2006 2009 2012 2015 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 2006 2009 2012 2015
Total farm-related employment (including food and beverage processing) Total farm employment
SOURCES: Bureau of Economic Analysis (2016b) (farm employment), Bureau of Labor Statistics (2016) (food and beverage processing employment). NOTES: Employment in food and beverage processing is taken from the Bureau of Labor Statistics Quarterly Census of Employment and Wages (QCEW) series which begins in 1975. Total farm employment includes crop and animal production and forestry, fishing and hunting, and related activities (agricultural services). Employment includes full-time, part-time, and seasonal jobs.
Agriculture and Farm Characteristics
Dairy cows in the valley Dairy cows produce milk—a significant portion of the valley’s agricultural revenues—and nitrogen—a growing environmental management challenge. To estimate trends in both milk production and nitrogen excretion, we
23 QCEW is less complete for on-farm employment because it excludes employment not subject to unemployment insurance. It also excludes most government employment, so it does not provide an appropriate base for estimating the share of farm-related employment in total employment. 24 To estimate non-disclosure gaps in the employment data, we used the same techniques as discussed in footnote 22. Additionally, since the BEA employment data do not report food and beverage separately from other non-durable goods, we combined farm employment from BEA and food and beverage employment from QCEW. These two series have consistent definitions of employment (number of jobs). QCEW only counts those covered under unemployment insurance, and it does not include self-employed workers, so it is not suitable for estimating farm employment. However, it provides a good estimate for the food and beverage industry.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 31
looked at post-war growth in dairy cow numbers in the valley (as summarized in Figure 4 in the main report). Table B1 shows trends in dairy cow numbers from 1945 to 2012, using Census of Agriculture data.
TABLE B1 All valley counties have seen significant expansion in number of dairy cows
1945–2012 1945 1950 1959 1974 1992 2002 2007 2012 % increase
Fresno 36,000 34,695 40,167 47,457 72,350 90,550 114,768 112,207 312%
Kern 11,830 9,962 10,844 20,913 34,566 74,708 124,756 130,828 1,106%
Kings 26,908 24,012 25,761 43,426 86,235 138,292 163,600 168,494 626%
Madera 11,430 13,209 13,100 13,496 24,259 48,086 76,811 67,769 593%
Merced 60,703 58,698 61,667 65,249 144,771 223,303 273,242 285,235 470%
San Joaquin 38,496 39,995 47,592 49,807 76,003 103,534 109,336 109,683 285%
Stanislaus 63,681 69,897 69,062 79,669 137,351 162,878 191,729 179,617 282%
Tulare 38,044 38,981 49,893 82,657 215,480 412,462 474,497 489,436 1,286%
San Joaquin Valley 287,092 289,449 318,086 402,674 791,015 1,253,813 1,528,739 1,543,269 538%
California 714,034 713,304 753,932 768,848 1,249,038 1,644,692 1,840,730 1,815,655 254%
SOURCE: USDA agricultural census (cows) (accessed from Haines et al. 2016). NOTES: For 1945, we use series “cows milked,” and for other years the series “cows kept for milk production.” The latter is generally slightly higher.
Farm size In 2012, there were approximately 20,000 irrigated farms in the San Joaquin Valley, close to 40 percent of the state’s irrigated farms. Irrigated farms already play a major role in local water management, and this role will expand with the implementation of the Sustainable Groundwater Management Act (SGMA). To that end, we were interested in looking at farm characteristics, especially size—which might affect how farmers respond to changing conditions brought on by SGMA. We were also interested in longer term farm size trends, given the widely held perception that farm consolidation is pervasive in the valley. We used Census of Agriculture data, available from Haines et al. (2016). This census reports numbers of irrigated farms by size, and the corresponding irrigated acreage. The size categories often vary from census to census, so we combined data into comparable categories to allow for the longest possible time series. Although some farm consolidation has occurred since 1969, there have not been major shifts (Figure B6). Since 1969, farms with more than 1,000 acres grew from 4 to 6 percent of total irrigated farms, and from 50 percent to 60 percent of irrigated acreage. Farms in the 100-449 and 500-999 acres range saw small increases in their shares, while the small farms in the 10-49 and 50-99 acres categories saw their shares drop. The share of the smallest farms (0-9 acres) doubled—jumping from 9 to 19 percent—but these farms are a very small portion of irrigated acreage (0.3%). The total number of irrigated farms went down from just over 24,000 in 1969 to 19,900 in 2012.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 32
Total irrigated acreage increased from 3.9 million acres in 1969 to 4.2 million acres in 2012.25 The increase in the share of smallest farms is partly due to the way the census identifies farms as “any place from which $1,000 or more of agricultural products were produced and sold, or normally would have been sold, during the census year.”26 This is a very low threshold, and it allows for many large residential properties to be counted as farms which would “normally” be able to produce and sell $1,000 of agricultural products.27 Even without the share of farms smaller than 10 acres, the share of farms between 10 and 500 acres is large—they represent 70 percent of all farms, and 25 percent of all acreage.
FIGURE B6 Even with some consolidation over time, valley farms are diverse in size
1969 46% 50%
21% 23% 16% 14% 9% 6% 6% 0.2% 4% 4%
0-9 acres 10-49 acres 50-99 acres 100-499 acres 500-999 acres >1000 acres Irrigated farms Irrigated acreage
60% 38% 2012 19% 12% 20% 18% 15% 0.3% 3% 3% 5% 6%
0-9 acres 10-49 acres 50-99 acres 100-499 acres 500-999 acres >1000 acres
Irrigated farms Irrigated acreage
SOURCE: USDA Census of Agriculture data from Haines et al. (2016). NOTE: The figure reports the share of irrigated farms for the eight San Joaquin Valley counties, and the share of irrigated acreage by farm size reported to the 1969 and 2012 agricultural censuses.
Farm sizes vary geographically as well. Table B2 uses 2012 census data to show that relatively small family farms and ranches still predominate in some eastern parts of the valley, while large agribusinesses managing thousands of acres occupy much of the southern and western farmland.
25 Irrigated acreage estimates reported in the Census of Agriculture are smaller than, and not as reliable as, those provided by USDA National Agricultural Statistics Service (reported in Figure 3 in the main report). For instance in 2012 the census reports 4.2 million irrigated acres, while NASS reports 5.5 million. 26 See USDA (2014). 27 See Koerth-Baker (2016) for a discussion of farm sizes in the Census of Agriculture.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 33
TABLE B2 Farm sizes in the valley vary geographically
Farms with Farms with Farms with Farms with 500- Farms with over Farms with 0-9 acres 10-49 acres 50-99 acres 100-499 acres 999 acres 1,000 acres Number Acreage Number Acreage Number Acreage Number Acreage Number Acreage Number Acreage Fresno 15% 0.3% 42% 4% 13% 4% 17% 16% 6% 17% 6% 59% Kern 11% 0.0% 20% 1% 8% 1% 31% 10% 11% 11% 19% 78% Kings 19% 0.1% 27% 1% 11% 1% 22% 9% 9% 11% 12% 77% Madera 8% 0.1% 29% 3% 20% 5% 27% 18% 7% 16% 8% 58% Merced 10% 0.2% 43% 4% 11% 3% 21% 17% 6% 15% 8% 61% San 20% 0.5% 40% 4% 11% 4% 19% 22% 5% 17% 5% 53% Joaquin Stanislaus 24% 1.1% 43% 9% 10% 6% 17% 34% 3% 15% 3% 34% Tulare 26% 0.7% 34% 5% 12% 5% 19% 24% 4% 17% 4% 48% All SJV 19% 0.3% 38% 3% 12% 3% 20% 18% 5% 15% 6% 60% SOURCE: USDA Census of Agriculture data from Haines et al. (2016). NOTES: The figure reports the share of irrigated farms for the eight San Joaquin Valley counties, and the share of irrigated acreage by farm size reported to the 2012 agricultural census. Table shows shares of each county total.
New irrigation-well construction In times of drought, when surface water supplies are scarce, farmers pump more groundwater to keep crops alive. During the latest drought, farmers in the San Joaquin Valley drilled a record number of new irrigation wells. More than 2,500 new irrigation wells were drilled in 2015, almost twice as many as during the peak of the drought in early 1990s (Figure B7). The increases were most significant in Fresno and Tulare Counties. Figure B7 uses data compiled by regional offices of Department of Water Resources (DWR).28 The data are aggregated from well completion reports submitted to DWR whenever a driller constructs, alters, or destroys a well (Department of Water Resources 2015). The well-completion reports go back to 1979, and they only provide information for additional wells drilled each year. From 1979 to 2015, more than 19,000 new irrigation wells were drilled. However, this number is most likely a subset of the total wells that exist today.29
28 For a related news article, see Sabalow (2016). 29 See Viers et al. (2012) for a discussion of number of irrigation wells in Tulare Basin prior to 1977.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 34
FIGURE B7 The latest drought saw a record number of new irrigation wells drilled in the valley
3,000
2,500
2,000
1,500
1,000
500
-
1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 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 Dry Years Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare
SOURCE: California Department of Water Resources (2015). NOTE: Data for San Joaquin County is underreported in 2015, since well-completion reports are still being processed by DWR.
Rural Communities
Drought and domestic wells In the latest drought, many rural communities in California have faced drinking water shortages. These issues affected San Joaquin Valley communities disproportionately. Many rural households in the valley rely on shallow domestic wells for drinking water. The extra pumping of groundwater for farming during this drought has likely increased the pace of domestic wells going dry. Table B3 updates the data reported in Hanak et al. (2015) on dry domestic wells. Although domestic wells are not directly under state oversight, the state’s drought emergency team has sought to track information on dry domestic wells with the goal of providing emergency drinking water supplies. From January 2014 to November 2016, close to 80 percent of dry domestic wells reported in California were located in San Joaquin Valley counties. Table B3 also reports estimates of the total number of domestic wells by county from a recent US Geological Survey study, which uses well-completion report data.30 The numbers reported are somewhat lower than those
30 Johnson and Belitz (2015) georeferenced all well completion reports provided by DWR (more than 600,000). Since well completion reports are submitted for all types of wells (including non-domestic ones) and the data was stored in image files, the authors came up with a spatially distributed randomized sampling routine to classify them. They randomly selected for viewing 10% of well completion reports within each township in California, and recorded the type of well to get a ratio of domestic wells to other wells. The ratio calculated from the “viewed” logs was applied to total number of completion reports in the township for an estimate of total domestic wells. Since not all of the well completion reports in the state have been digitized, the number of domestic wells might be underestimated.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 35
estimated in Viers et al. (2012) for the Tulare Basin counties, which drew on DWR well-completion reports available at the time (1977–2009), and also estimated the number of wells prior to 1977.
TABLE B3 Most domestic wells that went dry during the latest drought are in the valley
Number of domestic wells Number of domestic wells (estimates County reported dry from Johnson and Belitz (2015) Fresno 228 22,200 Kern 5 4,494 Kings 38 2,401 Madera 599 8,097 Merced 318 5,984 San Joaquin 14 7,400 Stanislaus 313 8,433 Tulare 1,609 10,235 Total San Joaquin Valley 3,124 69,244 Total California 3,918 290,154 SOURCES: California Governor’s Office of Planning and Research (2016): dry well reports (2016); Johnson and Belitz (2015): domestic well estimates. NOTES: Dry well counts are cumulative from January 2014 to November 2016. We report cumulative household water supply shortages reported to the state, including still active outages (“reported outages”) and already resolved outages (“Reported Resolved/Interim Solutions Obtained”).
Small water systems susceptible to contamination Figure B8 shows small water systems serving less than 3,300 people with contaminated wells and maximum contaminant limit (MCL) violations from 2002 to 2010. Nitrate (principally from farm runoff) and arsenic (naturally occurring) were the most frequent MCL violations, accounting for almost 80 percent of drinking water violations for small community systems. Such systems are especially prevalent in the Tulare Basin and Salinas Valley, but there are significant quality problems in many other regions, including the San Joaquin River hydrologic region. Small water systems are also particularly susceptible to increasing costs when drinking water standards become more stringent, because they do not benefit from economies of scale in water treatment.31 For instance, the introduction of new standards for Chromium 6 (which occurred after the data in this map were compiled) increased treatment costs in many groundwater-dependent systems.
31 For more on small water system problems and finance issues, see Chappelle et al. (2014).
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 36
FIGURE B8 Most small water systems with contaminated groundwater are located in the San Joaquin Valley
SOURCE: Authors’ calculations using data from State Water Resources Control Board (2013). NOTE: For population figures by county and region, see Table 4 State Water Resources Control Board (2013).
Local water and land management institutions Like California more generally, the San Joaquin Valley has evolved with a highly decentralized and often fragmented set of institutions to manage and oversee water and land use decisions. Table B4 summarizes the types and numbers of local and regional entities with managing and/or regulatory responsibilities over drinking water, irrigation water, water pollution, floods, land use, habitat, and air quality. Since most entities are listed by county, we used the eight-county definition of the valley; this results in the inclusion of some institutions outside the San Joaquin River and Tulare Lake hydrologic regions (e.g., in southeastern Kern County). Notes to Table B4 list the sources and the caveats for estimating numbers for each entity.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 37
TABLE B4 Decentralized local institutions manage and oversee most water and land use decisions in the valley
Local entities with water and land use
decision making responsibilities Number water Drinking water Irrigation pollution Water Floods use Land Habitat quality Air
Local governments: Cities 1 62 ◐ ○ ◐ ◐ ◐ ◐ ○ Counties 8 ◐ ○ ◐ ◐ ◐ ◐ ○ Water supply: Agricultural groundwater users (irrigation wells) 2 >19,900 ● ● ● Irrigation water suppliers 3 ~150 ◐ ● Community water systems 4 671 ◐ ◐ State small water systems 5 ~300 ● ● Household groundwater users (domestic wells) 6 ~70,000 ● ● Non-community water systems (e.g., schools) 7 ~1,300 ● ● Flood control: Land reclamation/levee districts 8 65 ◐ ◐ ◐ Flood control districts 9 25 ◐ ◐ ◐ Water pollution management: Wastewater agencies 10 179 ◐ ◐ Drainage districts 11 97 ◐ ◐ Central Valley Salinity Alternatives for Long-term Sustainability (CV-SALTS) 1 ◐ Habitat: National wildlife refuges (incl. Grasslands Wildlife Management Area) 12 10 ◐ ◐ California Department of Fish and Wildlife ecological reserves 27 ◐ ◐ and wildlife areas 13 State Parks 14 10 ◐ ◐ Private conservation areas (e.g., land trust preserves) 15 54 ● ● Resource conservation districts 16 27 ◐ ◐ Conservation easements held by non-profits and state agencies 17 105 ◐ ◐ Conservation easements held by federal agencies 18 ~390 ◐ ◐ Habitat conservation plans/Natural community conservation plans 19 24 ◐ ◐ Safe harbor agreements 20 3 ◐ ◐ CDFW-approved conservation banks 21 7 ◐ Integrated resource management: Integrated regional water management regions 22 17 ● ● ● ● Irrigated lands coalitions 23 12 ● ● ● ● Groundwater sustainability agencies (15 SGMA sub-basins) 24 >76 ◐ ◐ ◐ ◐ ◐
● Resource management ○ Regulation ◐ Resource management and regulation SOURCES: Listed for each table entry in the notes. Unless otherwise noted, we used the eight-county definition of San Joaquin Valley to estimate numbers for each institution, so the totals may include some institutions outside of the San Joaquin River and Tulare Lake hydrologic regions. NOTES: (1) We counted city governments in the eight counties, listed in the State Controller’s Office city data. (2) Number of irrigation wells comes from summarized DWR Well Completion Reports for 1979–2015 (see Figure B6 and related discussion). This may be an underestimate because there are no comprehensive estimates of how many wells drilled before 1979 are still in operation. (3) Irrigation water suppliers are districts that have a water supply function (per information in the State Controller’s Office special districts data) but do not have a drinking water delivery responsibility (per information in the USEPA’s Safe Drinking
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 38
Water Information System data). Our number likely slightly underestimates agriculture water suppliers because it excludes private and mutual water suppliers that exist in some parts of the valley. (4) We counted only active community water systems from USEPA Safe Drinking Water Information System. Most of these systems are very small. There are 481 community water systems with fewer than 200 service connections; 85 systems with 200-1,000 connections; 105 systems with more than 1,000 connections. (5) State small water systems were estimated using county-level data provided by California Department of Public Health in 2013. (6) Domestic well estimates are from Johnson and Belitz (2015). For county-level estimates see Table B3. (7) We counted active transient and non-transient non-community systems, listed in USEPA Safe Drinking Water Information System. (8) Source for number of land reclamation and levee districts is State Controller’s Office data. (9) Source for number of flood control districts is State Controller’s Office data. (10) Source for number of wastewater agencies is State Controller’s Office data for cities and special districts and California Public Utilities Commission (CPUC) for private utilities. Wastewater agencies include 58 cities, 118 special districts, and 3 private utilities. (11) Source for number of drainage districts is State Controller’s Office data. (12) Number of National Wildlife Refuges is from US Fish and Wildlife, List of Refuges. (13) Number of CDFW ecological reserves and wildlife areas is from California Department of Fish and Wildlife, Ecological Reserves and Wildlife Areas of California list. (14) Number of State Parks is from California Department of Parks and Recreation. (15) Number of private conservation areas is from California Protected Areas Database, 2016. (16) Source for number of resource conservation districts is State Controller’s Office data. (17) Number of conservation easements held by state agencies and nonprofits is in California Conservation Easements Database. (18) Number of conservation easements held by federal agencies is from California Conservation Easements Database. (19) Number of habitat conservation plans is from US Fish and Wildlife Service (USFWS) Environmental Conservation Online System (ECOS). (20) Number of safe harbors is from USFWS ECOS. (21) Number of CDFW approved conservation banks is from CDFW. (22) We counted Integrated Regional Water Management in the San Joaquin River and Tulare Lake regions from DWR. (23) Number of Irrigated Lands Coalitions is from SWRCB. (24) We only counted basins in the San Joaquin River and Tulare Lake hydrologic regions. Number of SGMA basins is from DWR.
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 39
REFERENCES Bureau of Economic Analysis. 2016a. Personal Income by Major Component and Earnings CA5/CA5N. (accessed on November 22, 2016). Bureau of Economic Analysis. 2016b. Total Full-Time and Part-Time Employment CA25/CA25N (accessed on November 22, 2016). Bureau of Labor Statistics. 2016. Quarterly Census of Employment and Wages (accessed on November 22, 2016). California Department of Fish and Wildlife. N.d.a. Ecological Reserves and Wildlife Areas of California (accessed on December 6, 2016). California Department of Fish and Wildlife. N.d.b. “Conservation and Mitigation Banks in California Approved by CDFW” (accessed on December 6, 2016). California Governor’s Office of Planning and Research. 2015. California Household Water Shortage Data (accessed on November 28, 2016). California Public Utilities Commission. N.d. Regulated Water & Sewer Utilities (accessed on December 6, 2016). Chappelle, Caitrin, Andrew Fahlund, Emma Freeman, Brian Gray, Ellen Hanak, Katrina Jessoe, Jay Lund, Josué Medellín-Azuara, Dean Misczynski, David Mitchell, James Nachbaur and Robyn Suddeth. 2014. Technical Appendix B: Estimates of Water Sector Expenditures, Revenues, and Needs. Paying for Water in California. PPIC. Department of Water Resources. 2015. Integrated Regional Water Management 48 IRWM Planning Regions Updated: December, 2015 (accessed on December 6 2016). GreenInfo Network. 2015. California Conservation Easement Database (accessed on November 7, 2016). GreenInfo Network. 2016. California Protected Areas Database (accessed on November 7, 2016). Haines, Michael, Price Fishback, and Paul Rhode. 2016. United States Agriculture Data, 1840 - 2012. ICPSR35206-v3. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor]. http://doi.org/10.3886/ICPSR35206.v3 Johnson, Tyler, and Kenneth Belitz. 2015. “Identifying the Location and Population Served by Domestic Wells in California.” Journal of Hydrology: Regional Studies. http://dx.doi.org/10.1016/j.ejrh.2014.09.002 Koerth-Baker, Maggie. 2016. “Big Farms Are Getting Bigger and Most Small Farms Aren’t Really Farms At All,” November 17, 2016. FiveThirtyEight.com. Lang, Marissa. 2016. “California Farm Revenue Plummets After Years of Drought.” San Francisco Chronicle. August 31. Peters, May, Suchada Langley, and Paul Westcott. 2009. “Agricultural Commodity Price Spikes in the 1970s and 1990s: Valuable Lessons for Today.” USDA Economic Research Service. Sabalow, Ryan, Dale Kasler, and Phillip Reese. 2016. “Farmers Say, ‘No Apologies,’ as Well Drilling Hits Record Levels in San Joaquin Valley.” Sacramento Bee. September 25. State Controller’s Office. 2016a. Cities Raw Data for Fiscal Years 2003–2015 (accessed on December 6). State Controller’s Office. 2016b. Special Districts Raw Data for Fiscal Years 2003–2015 (accessed on December 6). State Water Resources Control Board. 2013. Communities that Rely on a Contaminated Groundwater Source for Drinking Water. Report to the California Legislature. State Water Resources Control Board. 2016. Irrigated Lands Regulatory Program (ILRP)—Information About Coalition Groups (accessed on December 6, 2016). US Department of Agriculture. 2014. United States Summary and State Data Volume 1 • Geographic Area Series • Part 51. US Environmental Protection Agency. 2016. Safe Drinking Water Information System, Federal Reports Search (accessed on October 10, 2016). US Fish & Wildlife Service. N.d.a. Refuge List by State. (accessed on December 6, 2016). US Fish & Wildlife Service. N.d.b. Environmental Conservation Online System: Conservation Plans by type and US FWS Region (accessed on December 6, 2016). Viers, Joshua, Daniel Liptzin, Todd Rosenstock, Vivian Jensen, Allan Hollander, Alison McNally, Aaron King, Giorgos Kourakos, Elena Lopez, Nicole De La Mora, Anna Fryjoff-Hung, Kristin Dzurella, Holly Canada, Sarah Laybourne, Chiara McKenney, Jeannie Darby, James Quinn, and Thomas Harter. 2012. Nitrogen Sources and Loading to Groundwater. Technical Report 2 in Addressing Nitrate in California’s Drinking Water with a Focus on Tulare Lake Basin and Salinas Valley Groundwater. Report for the State Water Resources Control Board Report to the Legislature. Center for Watershed Sciences, University of California, Davis
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 40
Water Stress and a Changing San Joaquin Valley
Technical Appendix C: Native Species in the San Joaquin Valley: Drivers of Water and Land-Use Regulations
CONTENTS Table C1 43
Nathaniel Seavy and Peter Moyle
Supported with funding from the S. D. Bechtel, Jr. Foundation, the TomKat Foundation, and the US Environmental Protection Agency
Native Species in the San Joaquin Valley: Drivers of Water and Land-Use Regulations
Valley Native Species: Drivers of Water and Land-Use Regulations Our goal was to identify vertebrate species that are currently driving the regulatory context of the San Joaquin Valley, species that have already disappeared from the valley and are no longer drivers of management, and species that could become regulatory drivers in the future. We defined the San Joaquin Valley as the area from the Sacramento/San Joaquin Delta south to the Tulare Basin, from the Valley floor up to an elevation of about 500 feet. This area includes species associated with rivers (below the major dams), wetlands, and uplands. We defined three categories of vertebrate species:
. Extinct or extirpated. These are species that once occurred in the San Joaquin Valley, but are either extinct, extirpated, or occur at such low densities that they are not major drivers of land management or regulation in this region. Examples include red-legged frog, southwestern willow flycatcher, and pronghorn. . Management drivers. Federal- or state-listed species that currently drive management and regulation in the San Joaquin Valley. This list was derived from the California Department of Fish Wildlife (CDFW), Natural Diversity Database, Special Animals List. . Potential management drivers in the future. Species of special concern that could become federally or state-listed in the future and would have a greater impact on management and regulation in the San Joaquin Valley. This list was based on the California Species of Special Concern lists and expert opinion on the distribution of these species. Species with widespread distributions across California (e.g., loggerhead shrike and northern harrier) were not included. For all taxa we included all priority levels of the Species of Special Concern lists. Already, many of these species are addressed proactively by state and federal agencies and through voluntary conservation actions. However, if they were to be listed as threatened or endangered the level of regulation would be increased.
The list in Table C1 covers only vertebrate wildlife, and is not inclusive of all taxa (e.g., bats were excluded because information on historical and current distribution is limited). Taxonomy follows CDFW (2016). 9
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 42
TABLE C1 List of species currently driving regulatory context in the San Joaquin Valley
Fish Extinct or extirpated Thicktail chub, Siphatales crassicauda
Sacramento perch, Archoplites interruptus SSC
Current drivers
Delta smelt, Hypomesus transpacificus FT,SE
Central Valley spring Chinook salmon, Oncorhynchus tshawytscha FT,ST
Central Valley fall Chinook salmon, Oncorhynchus tshawytscha SSC
Steelhead (Central Valley DPS), Oncorhynchus mykiss irideus FT
Potential future drivers
Pacific lamprey, Entosphenus tridentata SSC
Kern brook lamprey, Lampetra hubbsi SSC
Sacramento hitch, Lavinia e. exilicauda SSC
White sturgeon, Acipenser transmontanus SSC
Sacramento splittail, Pogonichthys macrolepidotus SSC
Hardhead, Mylopharodon conocephalus SSC
Riffle sculpin, Cottus gulosus SSC
Amphibians Extinct or extirpated
Foothill yellow-legged frog, Rana boylii SSC
California red-legged frog, Rana draytonii FT, SSC
Current drivers
California tiger salamander, Ambystoma californiense FT, ST
Potential future drivers
Western spadefoot toad, Spea hammondii SSC[1]
Reptiles Extinct or extirpated Current drivers
Blunt-nosed leopard lizard, Gambelia sila FE,SE
Giant gartersnake, Thamnophis gigas FT,ST
Potential future drivers
Western pond turtle, Emys marmorata SSC
California glossy snake, Arizona elegans occidentalis SSC
San Joaquin coachwhip, Masticophis flagellum ruddocki SSC
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 43
Coast horned lizard, Phrynosoma blainvillii SSC
Northern California legless lizard, Anniella pulchra SSC
Birds Extinct or extirpated
California condor, Gymnogyps californianus FE,SE
Western yellow-billed cuckoo, Coccyzus americanus occidentalis FT,SE
Southwestern willow flycatcher, Empidonax traillii extimus FE,SE
Current drivers
Swainson's hawk, Buteo swainsoni ST
Greater sandhill crane, Grus canadensis tabida ST
Least Bell's vireo, Vireo bellii pusillus FE,SE
Potential future drivers
Fulvous whistling-duck, Dendrocygna bicolor SSC
Tricolored blackbird, Agelaius tricolor SSC
Least bittern, Ixobrychus exilis SSC
Black tern, Chlidonias niger SSC
Burrowing owl, Athene cunicularia SSC
Yellow warbler, Dendroica petechia SSC
Yellow-breasted chat, Icteria virens SSC
Redhead, Aythya americana SSC
Lesser sandhill crane, Grus canadensis canadensis SSC
Short-eared owl, Asio flammeus SSC
Song sparrow "Modesto" population, Melospiza melodia SSC
Mountain plover, Charadrius montanus SSC
Mammals (except bats) Extinct or extirpated
Gray wolf, Canis lupus FE,SE
Grizzly bear, Ursus arctos californicus Pronghorn, Antilocapra Americana Tule elk, Cervus canadensis nannodes Current drivers
Buena Vista Lake ornate shrew, Sorex ornatus relictus FE, SSC
Riparian brush rabbit, Sylvilagus bachmani riparius FE, SE
Nelson’s antelope squirrel, Ammospermophilus nelsoni ST
Giant kangaroo rat, Dipodomys ingens FE, SE
PPIC.ORG/WATER Technical Appendices Water Stress and a Changing San Joaquin Valley 44
Fresno kangaroo rat, Dipodomys nitratoides exilis FE, SE
Tipton kangaroo rat, Dipodomys nitratoides nitratoides FE, SE
Riparian (=San Joaquin Valley) woodrat, Neotoma fuscipes riparia FE, SSC
San Joaquin kit fox, Vulpes macrotis mutica FE,ST
Potential future drivers
Short-nosed kangaroo rat, Dipodomys nitratoides brevinasus SSC
Tulare grasshopper mouse, Onychomys torridus tularensis SSC
SOURCES: CDFW (2016), Moyle et al. (2015), Shuford and Gardali (2008), Thomson et al. (2008). NOTES: SSC – species of special concern, FE – federally listed endangered species, SE – state-listed endangered species, FT – federally listed threatened species, ST – state-listed threatened species.
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REFERENCES Moyle, Peter, Rebecca Quiñones, Jacob. Katz, and Jeff Weaver. 2015. Fish Species of Special Concern in California. California Department of Fish and Wildlife, Sacramento. Shuford, David, and Thomas Gardali, editors. 2008. California Bird Species of Special Concern: A Ranked Assessment of Species, Subspecies, and Distinct Populations of Birds of Immediate Conservation Concern in California. Studies of Western Birds 1. Western Field Ornithologists, Camarillo, California, and California Department of Fish and Game, Sacramento. Thomson, Robert, Amber Wright, and Bradley Shaffer. 2016. California Amphibian and Reptile Species of Special Concern. University of California Press. California Department of Fish and Wildlife (CDFW). 2016. Natural Diversity Database, Special Animals List.
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