California Water Plan Update 2005

**Volume 3** Regional Reports 6 9 problems. These include groundwater contamination from septic tank discharges in urban subdivisions near Susanville and Eagle Lake, and MTBE contamination in South Lake Tahoe. Drinking water quality has also become a greater issue for many surface water systems around Lake Tahoe, forcing many of the smaller private systems to consolidate or changeownership because they are unable to afford the new monitoring and treatment regulatory requirements. South Tahoe Public Utility District, the largest water purveyor in the Tahoe basin, is also experiencing some difficulty in meeting these water quality requirements. The abandoned Leviathan Mine, a Superfund site in the upper reaches of the Carson River watershed, impactslocal creeks with acid mine drainage water. The top water quality issues emerging from the Lahontan Regional Water Quality Control Board’s (RWQCB’s) 2003 Triennial Review included proposals to revise the waste discharge prohibition for piers in Lake Tahoe, and sodium standards for the Carson and Walker Rivers and their tributaries.
Lake Tahoe is the subject of its own chapter in the region’s basin plan, and receives many specific and extraordinary water quality protections. The Porter-Cologne Water Quality Control Act bans the discharge of domestic wastewater from California in the Lake Tahoe Basin; the same ban is in effect in Nevada by executive order, resulting in the export of all domestic wastewater from the basin. Discharges of industrial wastewater, wastes from boats and marinas, food wastes, and solid waste are also prohibited in the Tahoe basin. Lake Tahoe’s clarity has declined as development has increased around the shoreline, increasing the sediment load and nutrients reaching the lake and its tributaries. In the late 1960s, the clarity of the lake – as measured by the depth to which a Secchi disk (a small white disk of specific size) is visible – was about 100 feet; but in recent years, the average Secchi disk visibility has been closer to 70 feet. Nutrients, such as nitrogen and phosphorous used in landscaping fertilizers, can enter the lake via storm waterrunoff, promoting growth of algae and thereby reducing clarity

. Nitrogen pollution in the basin is primarily due to vehicles, while phosphorous is mostly derived from erosion and dust (phosphate-based detergents are banned).
Roads and road maintenance, including snow removal and de-icing, are the focus of new restrictions that are intended to reduce erosion and other water quality impacts into the streamsthat enter Lake Tahoe. The traditional use of salt for road deicing had resulted in adverse impacts to the trees and plants which help prevent erosion and sediment from flowing into the lake. Forest fires, grazing, and logging also present a threat to the lake’s water clarity due to related and subsequent erosion into the stream systems. The use of agricultural pesticides in the Lake Tahoe Basin is prohibited, and the Tahoe Regional Planning Agency has more recently banned the use of two-stroke engines in all boats on Lake Tahoe, to prevent contamination from gasoline components such as benzene and MTBE. Other restrictions on land development and soil disturbances are used in the continuing efforts to maintain or improve the lake’s water quality, and programs that purchase and preserve sensitive lands are being implemented. Lake Tahoe is now extensively monitored by many federal and State agencies, and researchers such as the University of California, Davis, Tahoe Research Group, and the University of Nevada Desert Research Institute.
Local California interests in the northern part of the Lahontan Region have been apprehensive for several years about plans and proposals from northern Nevada interests in the Reno area that have envisioned the development of additional water supplies from the northeastern California watersheds. In the late 1980s, the Silver State Plan triggered concerns about water exports to Nevada from as far north as ModocCounty, more than 150 miles north of Reno. The plan proposed building a pipeline north nearly to the Oregon border to tap groundwater basins, some of which extend across the California-Nevada line. More recently, the proposed Truckee Meadows Project has generated concern about potential depletion of California groundwater supplies in the Honey Lake and Long Valley Creek areas. To date, none of these proposals have been finalized or implemented. 

### Accomplishments Years of disputes over the waters of the Truckee and Carson rivers led to the enactment of the Truckee-Carson-Pyramid Lake Water Rights Settlement Act (Public Law 101-618) in 1990. Provisions of the Settlement Act, including interstate water allocation, will not take effect until several conditions are completed, which include the negotiation and approval of a new Truckee River Operation Agreement (TROA). The act specifies an interstate allocation of the waters between California and Nevada, provides for the settlement of Native American water rights claims at Pyramid Lake, and pro

v ides water supplies for specified environmental purposes in Nevada. When it is implemented the act will allocate to California 23,000 acre-feet of surface water annually in the Lake Tahoe Basin, and 32,000 acre-feet of surface water annually in the Truckee River Basin below Lake Tahoe. In the Carson River Basin California will receive water allocations that correspond to existing water uses, and the remainder of the water supplies from both watersheds will be allocated to uses in Nevada.7 9 **Chapter 9** North Lahontan Hydrologic Region California Water Plan Update 2005

Negotiation of a proposed Truckee River Operating Agreement began in 1991, involving California and Nevada, the U.S. Department of Interior, the Pyramid Lake Paiute Indian Tribe, Sierra Pacific Power Company, and local water users in both California and Nevada. The language for this 220-page draft operating agreement was finalized in October 2003, and the draft EIR/EIS for implementation of the TROA was released in mid-2004. After the final EIS/EIR is completed and certified, the negotiating parties will sign TROA. When executed, the TROA would establish new daily river operations procedures to meet water rights on the Truckee River and to enhance spawning flows in the lower Truckee River for the threatened fishery species of cui-ui and Lahontan cutthroat trout. TROA would provide formanagement of water in the Truckee basin in California, includi ng instream flow requirements and reservoir storage for fisheryand recreation uses, and would include procedures for coordin ating releases and exchanges of water among the watershed’s reservoirs. TROA would become the exclusive federal regulations governing water stored in Lake Tahoe, Martis Creek, Prosser Creek, Stampede, and Boca reservoirs. The agreement wouldalso provide an accounting procedure for surface and groundwater diversions in California’s part of the Truckee Basin and would enhance streamflows for recreational purposes.
Programs to manage and restore the water quality and clarity of Lake Tahoe are making progress by regulating developmentwithin the basin and by working to reduce surface water pollutants from entering the lake. The Tahoe Regional Planning Agency is a bistate agency created by Congress with authority to set regional environmental standards, issue land use permits,including conditions to protect water quality, and take enforcem ent actions throughout the basin. TRPA’s regional plan includes specific goals and timetables for accomplishing environmental objectives, and this bi-state agency also implements capital improvement programs to repair environmental damage and restore water quality. TRPA has identified nearly $500 million in capital improvements that are needed to achieve the regional plan’s environmental targets. Federal, state, and local govern

m ents have invested nearly $90 million in erosion control, storm water drainage, stream zone restoration, public transit, andother capital projects. The USFS’s Lake Tahoe Basin Management Unit controls more than 70 percent of the land in the Lake Tahoe Basin. The LTBMU has begun a watershed restorationprogram and a land acquisition program to prevent developm ent of sensitive private lands. Within the California side of this basin, the Lahontan Regional Water Quality Control Board has a major role in protecting Lake Tahoe, by actively monitoring and enforcing surface water quality for all uses and discharges. In recent years, federal and state agencies have increased funding to protect the environment of Lake Tahoe. Nevada approved a $20 million bond measure to perform erosion control and other measures on the east side of the lake. In California, Proposition 204 recently provided $10 million in bond funds for land acqui

sition and programs to control soil erosion, restore watersheds, and preserve environmentally sensitive lands.
On the Carson and Walker rivers, the California Department of Fish and Game is also concerned about maintaining instream flows and reservoir pools to restore and preserve the fishery. In conjunction with American Land Conservancy, a private land trust organization, DFG has been acquiring lands and water rights at Heenan Lake in the upper watershed of the East Fork of the Carson River. This small reservoir was originally built to supply irrigation water for Nevada, but it is now being used by DFG to raise Lahontan cutthroat trout to stock in other locations throughout the Sierra Nevada. Selected sections of the upper Carson River tributaries are managed by DFG as wild trout waters, where stocking of hatchery fish is not allowed. The goal of these efforts is to maintain and preserve the trout fishery in both the upper Carson and Walker rivers, which are recog

nized as some of the best trout fishing in the state.


## Relationship with Other Regions Because the river channels of the Truckee, Carson and Walker rivers’ naturally flow into Nevada, a large amount of the surface water from these watersheds has historically been reserved for use by Nevada interests under various interstate water rights settlements and agreements. Most of the surplus flows from these three rivers also flow into Nevada, where it is used for a variety of purposes. There are two small historic exports of surface water out of the North Lahontan hydrologic region to the Sacramento River region. At Echo Lakes in the upper Lake Tahoe Basin, an average of about 2,000 acre-feet per year is exported through a tunnel into the south fork of the American River in conjunction with a hydroelectric power development that began in 1876. Another water export of about 6,000 acre-feet per year is taken from the upper reaches of the Little Truckee River for irrigation use in Sierra Valley (a part of the Feather River Basin within the Sacramento River region). Near the southern end of the North Lahontan region another small water diversion exists, providing surface water from the upper tributaries of the Walker River to the Mono Lake Basin for summer irrigation purposes.

The only water import into the North Lahontan region occurs in northern Lassen County, where an average of about 3,000 acre-feet is imported from a tributary of the South Fork Pit River (Sacramento River Region) for irrigation in the Madeline Plains area.California Water Plan Update 2005

**Volume 3** Regional Reports 8 9 

## Looking to the Future The northern part of this hydrologic region contains portions of Modoc, Lassen and Sierra counties, in which no major changes in water use are anticipated in the near future. A small amount of agricultural expansion may be possible in areas that can support additional groundwater development. Likewise, the modest need for additional municipal and irrigation supplies can be met by some expansion of present surface systems or by increased use of groundwater.
Concern for protecting the limited groundwater resources of the region has led to establishment of formal groundwater management programs in the Honey Lake and Long Valley basins. In Modoc County, similar groundwater proposals are being considered for the Surprise Valley region. At present, neither the Honey Lake nor Long Valley groundwater manage

ment districts are active, but can be activated when needed. In the Lake Tahoe and Truckee River basins, the proposed Truckee River Operating Agreement (TROA) interstate allocation would also establish limits on groundwater procedures and withdrawal limits from these areas.

T he interstate surface waters of the Truckee, Carson and Walker rivers are controlled by federal watermasters according to existing federal court decrees. Each of these legal decrees may be revised to some degree within the next decade, as a result of TROA implementation on the Truckee River and through mediation regarding the Walker River water uses. Since further water development in these basins may be limited, especially in Nevada, water transfers are expected to play an increasing role to meet changing and higher-priority needs. In Nevada, such water transfers have already occurred through the acquisition of agricultural lands and water rights which are then transferred to meet municipal needs in Reno/Sparks region.

Within the Placer and Nevada county portions of the North Lahontan region, several large residential and commercial developments are being proposed for the Truckee and Martis Valley regions. If these developments are completed, it is likelythat significant new demands will be placed on the groundwater supplies and sewage disposal capabilities of this region.



## Water Portfolios for Water **Y ears 1998, 2000, and 2001**  Water year 1998 was a wet year for this region, with annual
pr ecipitation at 142 percent of normal, while the statewide annual precipitation was 171 percent of average. Year 2000 represents approximately normal hydrologic conditions with annual precipitation at 89 percent of average for the North Lahontan region. 2001 reflected dry-water-year conditions with annual precipitation at 49 percent of average. For comparison, statewide average precipitation in year 2001 was 72 percent of normal. Table 9-1 provides more detailed information about the total water supplies available to this region for these three specific years from precipitation, imports and groundwater, and also summarizes the uses of all of the water supplies. The data in Table 9-1 shows that more water from these three interstate rivers flows into Nevada than is consumptively used in the North Lahontan region.

A

more detailed tabulation of the dedicated portion of thetotal available water used for urban, agricultural and environmental purposes is presented in Table 9-2. Because most of the North Lahontan region is largely undeveloped, dedicated environmental water uses are a larger component of the total developed water uses in this region. Table 9-2 also provides detailed information about the sources of the developed water supplies, which are obtained from a mix of both surface water and groundwater supplies. The water portfolio tables at the end of this chapter summarize the detailed regional water accounting for all agricultural, urban and dedicated environ

m ental water uses of the region. Graphical representations of the regions water supplies and uses are also presented in the water portfolio diagrams in Figures 9-4 and 9-5.



## Selected References 2002 California 305(b) Report on Water Quality, State Water Resources Control Board C alifornia’s Groundwater Bulletin 118-03, Update 2003, California Department of Water Resources N onpoint Source Program Strategy and Implementation Plan, 1998-2013, State Water Resources Control Board, California Coastal Commission, January 2000 S trategic Plan, State Water Resources Control Board, Regional Water Quality Control Boards, November 15, 2001 T

ruckee River Operation Agreement, Draft October 2003 W ater Quality Control Plan, Regional Water Quality Control Board W atershed Management Initiative Chapter, Regional Water

Quality Control Board9 9 **Chapter 9** North Lahontan Hydrologic Region California Water Plan Update 2005

**Water Entering the Region** Precipitation 10,655 6,708 3,756 Inflow from Oregon/Mexico 0 0 0 Inflow from Colorado River 0 0 0 Impor ts from Other Regions 3 3 3 **Total 10,658 6,711 3,759 Water Leaving the Region**  Consumptive Use of Applied Water * 263 327 307 (Ag, M&I, Wetlands) Outflow to Nevada 1,391 754 552 Exports to Other Regions 12 12 9 Statutor y Required Outflow to Salt Sink 180 141 113 Additional Outflow to Salt Sink 83 92 92 Evaporation, Evapotranspiration of Native Vegetation, Groundwater Subsurface Outflows, 8,572 5,493 3,223 Natural and Incidental Runoff, Ag Effective Precipitation & Other Outflows **Total 10,501 6,819 4,296 Storage Changes in the Region**  [+] Water added to storage [-] Water removed from storage Change in Surface Reservoir Storage 147 -66 -430 Change in Groundwater Storage ** 10 -42 -107 **Total 157 -108 -537**

Applied Water * (compare with Consumptive Use) 432 524 490

*Footnote for applied water Consumptive use is the amount of applied water used and no lon ger available as a source of supply. Applied water is greater than consumptive use because it includes consumptive use, reuse, and outflows.

**Footnote for change in Groundwater Storage

C hange in Groundwater Storage is based upon best available information. Basins in the north part of the state (North Coast, San Francisco, Sacramento River and North Lahontan regions and parts of Central Coast and San Joaquin River regions) have been modeled – spring 1997 to spring 1998 for the 1998 water year and spring 1999 to spring 2000 for the 2000 water year. All other regions and year 2001 were calculated using the following equation:
GW change in storage = intentional recharge + deep percolation of applied water + conveyance deep percolation - withdrawals
This equation does not include the unknown factors such as natu ral recharge and subsurface inflow and outflow. Water Year (Percent of Normal Precipitation) 1998 (142%) 2000 (89%) 2001 (49%) **Table 9-1 North Lahontan Hydrologic Region Water Balance Summary - TAF**  Water Entering the Region – Water Leaving the Region = Storage Changes in RegionCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 10 9 Applied Net Depletion Applied Net Depletion Applied Net Depletion Water Use Water Use Water Use Water Use Water Use Water Use 2001 1998 2000

**WATER USE**

**DEDICATED WATER SUPPLIES Table 9-2**  **North Lahontan Hydrologic Region Water Use and Distribution of Dedicated Supplies (TAF)**

**Urban** Large Landscape 2.3 2.6 2.6 Commercial 9.0 9.7 9.3 Industrial 12.5 12.5 12.5 Energy Production 0.0 0.0 0.0 Residential - Interior 7.9 9.0 8.7 Residential - Exterior 6.2 6.3 7.2 Evapotranspiration of Applied Water 8.8 8.8 8.7 8.7 9.4 9.4 Irrecoverable Losses 0.0 0.0 0.0 0.0 0.0 0.0 Outflow 14.9 14.9 16.1 16.1 16.5 16.5 Conveyance Losses - Applied Water 0.0 0.0 0.0 Conveyance Losses - Evaporation 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Losses - Irrecoverable Losses 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Losses - Outflow 0.0 0.0 0.0 0.0 0.0 0.0 GW Recharge Applied Water 0.0 0.0 0.0 GW Recharge Evap + Evapotranspiration 0.0 0.0 0.0 0.0 0.0 0.0 **Total Urban Use 37.9 23.7 23.7 40.1 24.8 24.8 40.3 25.9 25.9 Agriculture**  On-Farm Applied Water 375.1 462.4 428.4 Evapotranspiration of Applied Water 241.1 241.1 301.3 301.3 281.1 281.1 Irrecoverable Losses 19.5 19.5 20.2 20.2 12.5 12.5 Outflow 66.8 66.8 75.8 75.8 74.7 74.7 Conveyance Losses - Applied Water 23.5 13.4 6.2 Conveyance Losses - Evaporation 2.3 2.3 1.7 1.7 1.0 1.0 Conveyance Losses - Irrecoverable Losses 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Losses - Outflow 1.5 1.5 1.1 1.1 0.0 0.0 GW Recharge Applied Water 0.0 0.0 0.0 GW Recharge Evap + Evapotranspiration 0.0 0.0 0.0 0.0 0.0 0.0 **Total Agricultural Use 398.6 331.2 331.2 475.8 400.1 400.1 434.6 369.3 369.3 Environmental**  Instream Applied Water 84.6 85.0 84.5 Outflow 84.6 84.6 85.0 85.0 84.5 84.5 Wild & Scenic Applied Water 404.1 233.3 152.5 Outflow 95.6 95.6 56.2 56.2 28.7 28.7 Required Delta Outflow Applied Water 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Managed Wetlands Habitat Applied Water 18.7 25.9 20.5 Evapotranspiration of Applied Water 13.2 13.2 19.8 19.8 16.9 16.9 Irrecoverable Losses 0.2 0.2 0.3 0.3 0.2 0.2 Outflow 0.0 0.0 0.6 0.6 0.0 0.0 Conveyance Losses - Applied Water 0.0 0.0 0.0 Conveyance Losses - Evaporation 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Losses - Irrecoverable Losses 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Losses - Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Total Managed Wetlands Use 18.7 13.4 13.4 25.9 20.7 20.7 20.5 17.1 17.1 **Total Environmental Use 507.4 193.6 193.6 344.2 161.9 161.9 257.5 130.3 130.3 TOTAL USE AND LOSSES 943.9 548.5 548.5 860.1 586.8 586.8 732.4 525.5 525.5** 

**Surface Water** Local Deliveries 501.4 501.4 501.4 469.5 469.5 469.5 311.8 311.8 311.8 Local Imported Deliveries 0.3 0.3 0.3 0.3 0.3 0.3 3.3 3.3 3.3 Colorado River Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 CVP Base and Project Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Other Federal Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 SWP Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Required Environmental Instream Flow 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Groundwater Net Withdrawal 41.8 41.8 41.8 112.0 112.0 112.0 189.6 189.6 189.6 Artificial Recharge 0.0 0.0 0.0 Deep Percolation 46.7 49.6 45.3 Reuse/Recycle Reuse Surface Water 348.7 223.7 161.6 Recycled Water 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0
**TOTAL SUPPLIES 943.9 548.5 548.5 860.1 586.8 586.8 716.6 509.7 509.7 Balance = Use - Supplies**  **0.0 0.0 0.0 0.0 0.0 0.0 -15.8 -15.8 -15.8**11 9 **Chapter 9** North Lahontan Hydrologic Region California Water Plan Update 2005



# Water Portfolios

North Lahontan Hydrologic RegionCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 12 9 **Table 9-3 North Lahontan region water portfolio (TAF)** 

ID North Lahontan North Lahontan North Lahontan Number: Flow Diagram Component (see legend) 1998 2000 2001 1 Colorado River Deliveries

- - - 2 Total Desalination

- - - 3 Water from Refineries

- - - 4a Inflow From Oregon

- - - b Inflow From Mexico

- - - 5 Precipitation 10,654.6 6,708.3 3,755.9 6a Runoff - Natural N/A N/A N/A b Runoff - Incidental N/A N/A N/A 7 Total Groundwater Natural Recharge N/A N/A N/A 8 Groundwater Subsurface Inflow N/A 9 Local Deliveries 501.1 464.6 381.9 10 Local Imports 0.3 0.3 0.3 11a Central Valley Project :: Base Deliveries

- - - b Central Valley Project :: Project Deliveries

- - - 12 Other Federal Deliveries

- - - 13 State Water Project Deliveries

- - - 14a Water Transfers - Regional

- - - b Water Transfers - Imported

- - - 15a Releases for Delta Outflow - CVP b Releases for Delta Outflow - SWP c Instream Flow Applied Water 84.6 85.0 84.5 16 Environmental Water Account Releases

- - - 17a Conveyance Return Flows to Developed Supply - Urban

- - - b Conveyance Return Flows to Developed Supply - Ag

- - - c Conveyance Return Flows to Developed Supply - Managed Wetlands

- - - 18a Conveyance Seepage - Urban

- - - b Conveyance Seepage - Ag 5.8 3.6 2.1 c Conveyance Seepage - Managed Wetlands

- - - 19a Recycled Water - Agriculture 5.0 5.0 5.0 b Recycled Water - Urban

- - - c Recycled Water - Groundwater

- - - 20a Return Flow to Developed Supply - Ag

- - - b Return Flow to Developed Supply - Wetlands

- - - c Return Flow to Developed Supply - Urban

- - - 21a Deep Percolation of Applied Water - Ag 19.8 28.9 29.3 b Deep Percolation of Applied Water - Wetlands 0.3 0.4 0.3 c Deep Percolation of Applied Water - Urban 12.8 13.3 12.6 22a Reuse of Return Flows within Region - Ag 27.9 36.2 30.8 b Reuse of Return Flows within Region - Wetlands, Instream, W&S 313.5 181.9 126.9 24a Return Flow for Delta Outflow - Ag

- - - b Return Flow for Delta Outflow - Wetlands, Instream, W&S

- - - c Return Flow for Delta Outflow - Urban Wastewater

- - - 25 Direct Diversions N/A N/A 26 Surface Water in Storage - Beg of Yr 853.2 903.5 837.6 27 Groundwater Extractions - Banked

- - - 28 Groundwater Extractions - Adjudicated

- - - 29 Groundwater Extractions - Unadjudicated 88.8 162.0 183.8 23 Groundwater Subsurface Outflow N/A N/A N/A 30 Surface Water Storage - End of Yr 1,000.0 837.6 407.8 31 Groundwater Recharge-Contract Banking

- - - 32 Groundwater Recharge-Adjudicated Basins

- - - 33 Groundwater Recharge-Unadjudicated Basins

- - - 34a Evaporation and Evapotranspiration from Native Vegetation N/A N/A N/A b Evaporation and Evapotranspiration from Unirrigated Ag N/A N/A N/A 35a Evaporation from Lakes 294.6 313.6 317.6 b Evaporation from Reservoirs 175.5 213.7 267.6 36 Ag Effective Precipitation on Irrigated Lands 62.6 32.5 12.2 37 Agricultural Water Use 374.8 457.6 428.4 38 Managed Wetlands Water Use 18.7 25.9 20.5 39a Urban Residential Use - Single Family - Interior 3.2 4.3 3.6 b Urban Residential Use - Single Family - Exterior 5.2 5.0 5.8 c Urban Residential Use - Multi-family - Interior 4.0 4.3 4.6 d Urban Residential Use - Multi-family - Exterior 1.0 1.1 1.2 40 Urban Commercial Use 8.3 9.0 8.5 41 Urban Industrial Use 14.3 14.3 14.4 42 Urban Large Landscape 2.2 2.4 2.5 43 Urban Energy Production

- - - 44 Instream Flow 84.6 85 84.5 45 Required Delta Outflow

- - - 46 Wild and Scenic Rivers 95.6 56.2 28.7 47a Evapotranspiration of Applied Water - Ag 241.1 298.2 281.1 b Evapotranspiration of Applied Water - Managed Wetlands 13.2 19.8 16.9 c Evapotranspiration of Applied Water - Urban 8.6 8.5 9.2 48 Evaporation and Evapotranspiration from Urban Wastewater

- - - 49 Return Flows Evaporation and Evapotranspiration - Ag 19.5 20.2 12.5 50 Urban Waste Water Produced 25.1 27 27.1 51a Conveyance Evaporation and Evapotranspiration - Urban

- - - b Conveyance Evaporation and Evapotranspiration - Ag 2.3 1.7 1

c Conveyance Evaporation and Evapotranspiration - Managed Wetlands 0.2 0.3 0.2 d Conveyance Outflow to Mexico N/A 52a Return Flows to Salt Sink - Ag 68 75.2 74.7 b Return Flows to Salt Sink - Urban 15.3 16.6 16.9 c Return Flows to Salt Sink - Wetlands

- 0.6

- 53 Remaining Natural Runoff - Flows to Salt Sink 180.2 141.2 113.2 54a Outflow to Nevada 1390.6 753.9 551.9 b Outflow to Oregon

- - - c Outflow to Mexico

- - - 55 Regional Imports 3.0 3.3 3.3 56 Regional Exports 11.9 11.8 10 59 Groundwater Net Change in Storage 9.8 -41.5 -107.2 60 Surface Water Net Change in Storage 146.8 -65.9 -429.8 61 Surface Water Total Available Storage 1,181.2 1,181.2 1,181.2
Inflows Outflows Green number signifies included in summary boxes**Chapter 9** North Lahontan Region 1 3 9 **Volume 3**  Regional Reports California Wa ter Plan Update 200 51 4 9 **Volume 3**  Regional Reports **Chapter 9** North Lahontan Region California Wa ter Plan Update 200 5

## Chapter 10 South Lahontan Hydrologic Region 

# Volume 3i 10 **Chapter 10** South Lahontan Hydrologic Region California Water Plan Update 2005 

# Chapter 10 South Lahontan Hydrologic Region

Contents Chapter 10 South Lahontan Hydrologic Region .......................................................................................................10-1 Setting ............................. 10-1 Climate ............................ 10-1 Population ....................... 10-2 Land Use ......................... 10-2 Water Supply and Use ...... 10-2 State of the Region ........... 10-5 Challenges .................. 10-5 Accomplishments ......... 10-8 Relationship with Other Regions ........................................................................................................................10-9 Looking to the Future ........ 10-9 Regional Planning ............ 10-9 Water Portfolios for Water Years 1998, 2000, and 2001 ..................................................................................10-11 Water Year 1998 ....... 10-11 Water Year 2000 ....... 10-11 Water Year 2001 ....... 10-11 Selected References ........ 10-12



## Boxes Box 10-1 Death Valley Temperatures .....................................................................................................................10-1 Box 10-2 Mojave River Adjudication .....................................................................................................................10-9



## Figures Figure 10-1 South Lahontan Hydrologic Region (map) ............................................................................................ 10-ii Figure 10-2 South Lahontan Hydrologic Region population .....................................................................................10-4 Figure 10-3 South Lahontan region water balance for water years 1998, 2000, 2001 (2 bar charts) .........................10-6 Figure 10-4 South Lahontan region - illustrated water flow diagram .......................................................................10-15 Figure 10-5 South Lahontan region - schematic flow diagram ................................................................................10-16



## Tables Table 10-1 South Lahontan Hydrologic Region water balance summary ...................................................................10-3 T able 10-2 South Lahontan Hydrologic Region water use and distribution of dedicated supplies .................................10-7 T able 10-3 South Lahontan region water portfolios ...............................................................................................10-14**Volume 3** Regional Reports California Water Plan Update 2005

Flow in TAF 1998 917 2000 1,509 2001 1065 **Tulare Lake Region** California Aqueduct (SWP) Flow in TAF 1998

1 2000 1 2001 1 **Nor th Lahontan Region**  Virginia Creek

Flow in TAF 1998 1,286 2000 1,695 2001 1,255 **South Coast Region** Los Angeles Aqueduct California Aqueduct (SWP)

**Some Statistics** Area -26,732 square miles (16.9% of State) Average annual precipitation - 7.8 inches Year 2000 population - 721,490 2030 population projection - 1,266,375 Total reservoir storage capacity - 459 TAF 2000 irrigated crop area - 65,080 acres .

.

.

.

.

. INYO

KERN

LOS ANGELES SAN BERNARDINO MONO **Figure10-1 South Lahontan Hydrologic Region**

The South Lahontan Hydrologic Region contains the Eastern Sierra and the Mojave Desert and includes both the highest point (Mount Whitney) and lowest point (Death Valley) in the lower 48 states. Arrows indicate annual flows entering and leaving the region for water years 1998, 2000, and 2001.1 10 **Chapter 10** South Lahontan Hydrologic Region California Water Plan Update 2005



# Chapter 10 South Lahontan Hydrologic Region

any significant agricultural areas. The floodwaters eventually flow south to a low-lying area near Silver Lake and Soda Lake, which is also the terminus for the Mojave River.



## Climate The climate of the South Lahontan region is generally arid. Annual average precipitation is less than 10 inches, except for the higher mountains. Annual average precipitation in the higher elevations of the Sierra Nevada ranges from 25 to 50 inches, which can generate significant snow accumulations for spring runoff. Some of the central and eastern portions of the Mojave Desert average 4 inches of precipitation annually. Death Valley receives a little less than 2 inches of rain on the average, but just a few tenths of an inch falls in some years (see Box 10-1). Daytime temperatures in the winter are generally cold in the mountains and mild in the desert valleys.
Precipitation for the region is summarized as part of regional water uses and supplies for recent years 1998, 2000 and 2001 in Table 10-1. Year 1998 was a very wet year in the South Lahontan region with 188 percent of normal precipi

tation (compared to 171 percent statewide). For year 2000 statewide precipitation was average (97 percent of normal), but the South Lahontan region was very dry with only 66 percent of normal precipitation. In the generally dry year 2001, the annual precipitation in this region was 91 percent of normal, while the statewide amounts averaged 72 percent of normal precipitation. 

## Setting Although the South Lahontan hydrologic region brings to mind images of desert with Joshua trees, sand dunes, and dry lakes, it also contains the glacier-carved topography of the eastern slopes of the Sierra Nevada and the eastern slopes of the San Gabriel and San Bernardino mountains. The northern half of the region includes Mono Lake, Owens Valley, Panamint Valley, Death Valley, and the Amargosa River Valley. The Mojave Desert occupies the southern half of the region, and is characterized by many small mountain ranges and valleys with playas, or dry lakes. The region has the highest and lowest elevation points in the continental United States: Mount Whitney with an elevation of 14,495 feet and Death Valley at 282 feet below sea level. The region includes all of Inyo County and parts of Mono, San Bernardino, Kern, and Los Angeles counties (Figure 10-1).` The South Lahontan region has fewer permanent rivers and streams due to the dryer hydrology on the east side of the Sierra Nevada. The largest river in this region is the Owens River, which flows from north to south over the length of Owens Valley. This river drains both the east side of the Sierra Nevada and the western slopes of the White Mountain range, and flowed into Owens Lake until 1913, when most of its flow was diverted for use in Los Angeles. Another important riverin the region is the Mojave River. Although seldom seen flowi ng on the surface, it has significant underground flow that supports nearly all the groundwater-supplied agriculture and urban population in the Mojave River Valley. The Amargosa River is the only other significant river in the region, but it only generates surface flows during flash floods and does not serve



## Box 10-1 Death Valley Temperatures
Death Valley experiences an oven-hot environment in the summer, when daytime maximum temperatures routinely reach the 110s and low 120s. Most seasons even see a few searing days with temperatures reaching the middle and upper 120s. A reading of 134 degrees was attained on a July day in 1913, the record for the wester n hemisphere.California Water Plan Update 2005

**Volume 3** Regional Reports 2 10 

## Population Although the South Lahontan region covers 16.9 percent of the land mass of the state, its year 2000 population was 721,490, roughly 2 percent of California’s total population. Nearly 450,000 people now live in the southern portion of the region, in the areas of Antelope, Apple, and Victor valleys. The cities of Palmdale and Lancaster were among the fastest-growing cities in the state in the 1990s. Rapid population growth is projected to continue over the next 25 years, based on projections fromthe State department of Finance. Figure 10-2 provides a graphical depiction of the South Lahontan region’s total population from 1960 through 2000, with current projections to 2030.



## Land Use The region supports a variety of urban and agricultural uses, including a moderate amount of agricultural acreage and several growing cities. Much of the land in the region remains undeveloped and is under protected or managed status for recreational, scenic, environmental, or military purposes. Even though 18,000 acres in the Antelope Valley remain agriculturally productive, that area and Victor Valley have now become highly urbanized. Other than these two valleys and the cities of Barstow and Ridgecrest, the rest of the region is rural and generally consists of widely scattered small towns with populations of less than 8,000. Agricultural land uses are concentrated in the Antelope and Owens valleys and along the Mojave River. Of the 65,000 acres of crops harvested in 2000, alfalfa and pasture grass constituted about 75 percent of the total acreage, while truck crops, mostly carrots and onions, represent about 12 percent.


## Water Supply and UseThe Los Angeles Aqueduct is the region’s major water developm ent feature. In 1913, the initial 223-mile-long aqueduct was completed by the Los Angeles Department of Water and Power (LADWP) and began transporting water from Owens Valley to the city of Los Angeles. The aqueduct was extended 115 miles The northern half of the South Lahontan region includes Mono Lake (in photo), Owens Valley, Panamint Valley, Death Valley, and the Amargosa River Valley. The Mojave Desert occupies the southern half of the region. (DWR photo)3 10 **Chapter 10** South Lahontan Hydrologic Region California Water Plan Update 2005

**Water Entering the Region** Precipitation 20,409 7,476 9,741 Inflow from Oregon/Mexico 0 0 0 Inflow from Colorado River 0 0 0 Impor ts from Other Regions 918 1,510 1,066 **Total 21,327 8,986 10,807**  **Water Leaving the Region** Consumptive Use of Applied Water * 259 321 316 (Ag, M&I, Wetlands) Outflow to Oregon/Nevada/Mexico 0 0 0 Expor ts to Other Regions 1,286 1,695 1,255 Statutory Required Outflow to Salt Sink 80 67 58 Additional Outflow to Salt Sink 111 150 126 Evaporation, Evapotranspiration of Native Vegetation, Groundwater Subsurface Outflows, 19,745 7,055 9,352 Natural and Incidental Runoff, Ag Effective Precipitation & Other Outflows **Total 21,481 9,288 11,107**  **Storage Changes in the Region** [+] Water added to storage [-] Water removed from storage Change in Surface Reservoir Storage 72 -8 -1 Change in Groundwater Storage ** -226 -294 -299 **Total -154 -302**  **-300 Applied Water ** * (compare with Consumptive Use) 480 612 570

*Footnote for applied water Consumptive use is the amount of applied water used and no lon ger available as a source of supply. Applied water is greater than consumptive use because it includes consumptive use, reuse, and outflows.

**Footnote for change in Groundwater Storage

C hange in Groundwater Storage is based upon best available information. Basins in the north part of the state (North Coast, San Francisco, Sacramento River and North Lahontan regions and parts of Central Coast and San Joaquin River regions) have been modeled – spring 1997 to spring 1998 for the 1998 water year and spring 1999 to spring 2000 for the 2000 water year. All other regions and year 2001 were calculated using the following equation:
GW change in storage = intentional recharge + deep percolation of applied water + conveyance deep percolation - withdrawals
This equation does not include the unknown factors such as nat ural recharge and subsurface inflow and outflow. Water Year (Percent of Normal Precipitation) 1998 (188%) 2000 (66%) 2001 (91%) **Table 10 -1 South Lahontan Hydrologic Region water balance summary - TAF**  Water Entering the Region – Water Leaving the Region = Storage Changes in RegionCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 4 10 north into the Mono Basin in 1940 and additional water was diverted. A second, 137-mile-long pipeline was completed in 1970. More recently, exports have been modifi ed and reduced as a result of litigation to preserve Mono Lake and to mitigate the dust problems that resulted from the diversion of water from Owens Lake.

There are eight small reservoirs in the Los Angeles Aqueduct system with a combined storage capacity of about 323,000 acre-feet. These reservoirs were built to store and regulate fl ows in the aqueduct. The northernmost reservoir is Grant Lake in Mono County. Six of the eight reservoirs are in the South Lahontan region. Bouquet and Los Angeles Reservoirs are in the South Coast region. Water from the aqueduct system passes through 12 hydropower plants on its way to Los Angeles. The annual energy generated is more than 1 billion kilowatt-hours, enough to supply the needs of 220,000 homes.

The only dam on the Mojave River, at the base of the San Bernardino Mountains, is the Mojave River Forks Dam. This U.S.Corps of Engineers fl ood control facility provides a maximum reservoir storage capacity of 179,400 acre-feet. The lower Mojave River is seldom seen fl owing on the earth’s surface. Instead it existsas groundwater underfl ow which supports much of the agriculture crops and urban population in the Mojave River Valley. Groundwater provides about 41 percent of the average annual water supply in the region. Groundwater is used conjunctivelywith surface water in the more heavily pumped basins. Seventysix groundwater basins underlie about 55 percent of this hydrologic region. The total estimated demand met by groundwater in the region is about 239,000 acre-feet, according to the 2003 update of DWR Bulletin 118 California’s Groundwater. Most of the groundwater production is concentrated, along with the population, in basins in the southern and western parts of this hydrologic region. Many other areas of this hydrologic regionare designated as public land and have low population density. As such, many of the groundwater basins have not been signifi cantly used, and there is thus little data available about groundwater volume and quality.
Five water agencies in the southwest portion of this region have contracts with the State Water Project for a total of about 250,000 acre-feet of surface water annually. The East Branch of the SWP California Aqueduct brings imported water into the region. Some of this SWP water is used to recharge groundwater in the Mojave River Valley. The Mojave Water Agency (MWA) has taken little of its SWP contract entitlement to date, although that may change in the near future as the water agency seeks ways to reduce the over-pumping of the groundwater basin. **Figure 10-2 South Lahontan Hydrologic Region population**

0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000

1960 1970 1980 1990 2000 2010 2020 2030

Data from California Department of Finance provide decadal population from 1960 to 2000 and population projection for 2030 for South Lahontan region.5 10 **Chapter 10** South Lahontan Hydrologic Region California Water Plan Update 2005

The Mojave Water Agency is developing a Regional WaterManagement Plan Update that will provide a regional framew

ork for managing water resources and ensuring reliable water for the future of the MWA desert region. While MWA relies predominately on groundwater, it also receives water from the California Aqueduct as one of 29 SWP contractors. The RWMPUpdate will address population growth, water demand project ions, stakeholder needs and issues, facilities needed to replenish groundwater supplies, and revenue alternatives.
Antelope Valley-East Kern Water Agency (AVEK) is the largest SWP water contractor in this region and one of the largest in the state. AVEK provides water to five major municipal agencies, 16 smaller water service agencies, Edwards Air Force Base, Palmdale Air Force Plant 42, and the U.S. Borax and Chemical Facilities. AVEK was formed to bring imported surface water from the SWP into this region.

T he 2,700 acre-feet capacity Littlerock Reservoir provides waterto Littlerock Creek Irrigation District and to Palmdale Water Dist rict (PWD). PWD recently funded most of a seismic rehabilitation of the original dam (constructed in 1924) in exchange for control of the water supply for the next 50 years. Water from Littlerock Reservoir is released into a canal that conveys flows to PWD’s Lake Palmdale, a 42,000 acre-foot storage reservoir.
In the San Bernardino Mountains, Lake Arrowhead, owned by the Arrowhead Lake Association, is a 48,000 acre-foot reservoir providing recreational opportunities and water for Arrowhead Woods property owners. Figure 10-3 provides a graphical summary of all the water supply sources that are used to meet the developed water uses in this hydrologic region for years 1998, 2000, and 2001.
In the northern part of the South Lahontan region, the town of Mammoth Lakes provides water from surface and groundwatersources to a permanent population of about 5,000, an average daily population of about 13,000, and a peak weekend and holiday period population of up to 30,000 people per day. In communities that are popular tourist destinations, this pattern of peak population and water use that is several times the permanent base level is a common water supply and distribution problem.
Most of the quantified environmental water demands (listed in Table 10-3) are in the northern part of this hydrologic region, and involve the restoration of the water surface elevation for Mono Lake. The required inflows are the result of several years of court litigation, and have resulted in improving water surface elevations in recent years. Another identified environmental water demand involves current and proposed, releases into the Owens River to restore flows that were previously intercepted for use in Los Angeles after 1913, and for use in restoring surface water to Owens Lake.

A lfalfa produced in the region uses groundwater as the primary source of irrigation water. In the Mono and Owens valleys, water supplies from the Los Angeles Aqueduct are sometimes used for flood irrigation of fields for improved production of native pasture grass. Ground and surface water is not the only source of water available to grow alfalfa. In the Antelope Valley region of Los Angeles County, 680 acres of alfalfa have been irrigated for the past 14 years with municipal effluent water. The treated water comes from the Lancaster Water Reclamation Plant owned and operated by County Sanitation District No. 14 of Los Angeles County.

The water balance data shown in Table 10-1 and Table 10-2 summarize the detailed regional water accounting contained in the water portfolio data sets for years 1998, 2000 and 2001. These tabulated water supplies and uses provide acomparison of how the patterns of water use and distribution can change from a very wet year (1998) to a dryer year (2000), and for an average water year such as 2001.


## State of the Region Challenges Many of the rapidly developing urban parts of this region are susceptible to shortfalls in available water supplies. For example, a recent study by the Antelope Valley Water Group concluded that the valley has low reliability to meet demandsfrom existing and future groundwater supplies, the SWP, Littlerock Reservoir, and recycling. The report further stated that the region could only expect to meet full 1998 water demands about half the time without overdrafting the groundwater resources. The capability to meet water demands for projected growth and development is a concern for many water agencies in the southern portions of the South Lahontan region. There is concern that overdrafting the groundwater resources will generate adverse environmental impacts, such as diminished flows in springs and surface streams that support wildlife.
The quality of the limited surface water resources is excellent in the region, and is greatly influenced by snowmelt from the eastern Sierra Nevada. However at lower elevations, groundwater and surface water quality can be degraded, both naturally from geothermal activity, and as a result of activities such as recreational uses and cattle grazing. Nutrients enter ingCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 6 10 **Figure 10-3 South Lahontan region water balance for water years 1998, 2000, 2001**

0 100 200 300 400 500 600 700 800

1998 2000 2001Thousand Acre-Feet Dedicated Environ
Reuse & Recycle Ground Water

State Project
Local Projects 0 100 200 300 400 500 600 700 800

1998 2000 2001Thousand Acre-Feet Instream Flow

Irrigated Agriculture

Urban

**Dedicated Water Supplies Applied Water Uses** 

Three years show a marked change in the amount and relative pro portions of water delivered to South Lahontan region’s urban and agricultural sectors and water dedicated to the environment ( applied water, top chart), where the water came from, and how much water was reused among sectors (dedicated water supplies, botto m chart).7 10 **Chapter 10** South Lahontan Hydrologic Region California Water Plan Update 2005

Applied Net Depletion Applied Net Depletion Applied Net Depletion Water Use Water Use Water Use Water Use Water Use Water Use 2001 1998 2000

**WATER USE Table 10-2**  **South Lahontan Hydrologic Region Water Use and Distribution of Dedicated Supplies (TAF)**

**DEDICATED WATER SUPPLIES Urban**  Large Landscape 8.4 6.6 5.3 Commercial 27.8 19.0 20.1 Industrial 8.1 4.7 5.6 Energy Production 6.3 6.3 6.3 Residential - Interior 86.4 137.0 113.5 Residential - Exterior 62.9 77.2 75.3 Evapotranspiration of Applied Water 71.3 71.3 83.8 83.8 80.6 80.6 E&ET and Deep Perc to Salt Sink 30.5 30.5 40.4 40.4 34.5 34.5 Outflow 32.0 32.0 49.5 49.5 35.6 35.6 Conveyance Applied Water 4.9 5.1 4.8 Conveyance Evaporation & ETAW 4.9 4.9 5.1 5.1 4.8 4.8 Conveyance Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Outflow 0.0 0.0 0.0 0.0 0.0 0.0 GW Recharge Applied Water 6.4 12.9 5.6 GW Recharge Evap + Evapotranspiration 0.0 0.0 0.0 0.0 0.0 0.0 **Total Urban Use 211.2 138.7 138.7 268.8 178.8 178.8 236.5 155.5 155.5**  **Agriculture** On-Farm Applied Water 280.6 361.0 344.0 Evapotranspiration of Applied Water 187.8 187.8 237.7 237.7 235.0 235.0 E&ET and Deep Perc to Salt Sink 5.7 5.7 7.3 7.3 6.7 6.7 Outflow 51.7 51.7 65.4 65.4 60.0 60.0 Conveyance Applied Water 0.0 0.0 0.0 Conveyance Evaporation & ETAW 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Outflow 0.0 0.0 0.0 0.0 0.0 0.0 GW Recharge Applied Water 0.0 0.0 0.0 GW Recharge Evap + Evapotranspiration 0.0 0.0 0.0 0.0 0.0 0.0 **Total Agricultural Use 280.6 245.2 245.2 361.0 310.4 310.4 344.0 301.7 301.7**  **Environmental** Instream Applied Water 98.4 88.8 78.4 Outflow 79.8 79.8 67.4 67.4 57.8 57.8 Wild & Scenic Applied Water 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Required Delta Outflow Applied Water 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Managed Wetlands Habitat Applied Water 0.0 0.0 0.0 Evapotranspiration of Applied Water 0.0 0.0 0.0 0.0 0.0 0.0 E&ET and Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Applied Water 0.0 0.0 0.0 Conveyance Evaporation & ETAW 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Total Managed Wetlands Use 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 **Total Environmental Use 98.4 79.8 79.8 88.8 67.4 67.4 78.4 57.8 57.8** 
**TOTAL USE AND OUTFLOW 590.2 463.7 463.7 718.6 556.6 556.6 658.9 515.0 515.0** 

**Surface Water** Local Deliveries 56.6 56.6 56.6 58.1 58.1 58.1 46.8 46.8 46.8 Local Imported Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Colorado River Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 CVP Base and Project Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Other Federal Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 SWP Deliveries 73.1 73.1 73.1 108.0 108.0 108.0 81.9 81.9 81.9 Required Environmental Instream Flow 79.8 79.8 79.8 67.4 67.4 67.4 57.8 57.8 57.8 Groundwater Net Withdrawal 226.2 226.2 226.2 294.1 294.1 294.1 299.0 299.0 299.0 Deep Percolation of Surface and GW 107.9 140.6 123.3 Reuse/Recycle Reuse Surface Water 18.6 21.4 20.6 Recycled Water 28.0 28.0 28.0 29.0 29.0 29.0 29.5 29.5 29.5

**TOTAL SUPPLIES 590.2 463.7 463.7 718.6 556.6 556.6 658.9 515.0 515.0**  **Balance = Use - Supplies 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0** California Water Plan Update 2005

**Volume 3** Regional Reports 8 10 Crowley Reservoir, on Owens River south of Mono Lake, have contributed to low dissolved oxygen levels in the reservoir. Water quality and quantity are inherently related in the Owens River watershed because of the large exports of surface and groundwater to the city of Los Angeles. Arsenic, a known human carcinogen, is a health concern in the basin, and therefore, in Los Angeles as well, especially with the recently proposed lower drinking water standard for this chemical. The vast majority of public water supply wells do meet drinking water standards. However, in places where these standards are exceeded, it is most often for TDS, fluoride, or boron. Several domestic water supply wells in the Barstow area have been closed due to historical contamination from industrial and domestic wastewater. Three military installations in the southwestern part of the region are on the federal Superfund National Priorities List because of volatile organic compounds and other hazardous contaminants, and the PG&E chromium groundwater contamination site in Hinkley is also within this region. In its triennial review, the Lahontan Regional Water Quality Control Board identified the need for site-specific ammonia objectives for Paiute Ponds and Amargosa Creek in Los Angeles County. Also, the monitoring and cleanup of chromium in groundwater and the cleanup of sites contami

nated by mining wastes are additional water quality needs for this region.

In the Owens Valley, a restoration project is in operation to mitigate for dust generated as a result of the City of Los Angeles diverting water from the Owens Lake into its aqueduct. The barren playa on Owens Lake at one time regularly exceeded federal standards for airborne particulate pollution due to the prevailing winds moving across the dry lakebed. After years of litigation, the Los Angeles Department of Water and Power is using water from the aqueduct to irrigate large tracts of lakebed to reduce the dust hazard in the area. To date significant reductions in airborne pollution have dramatically improved conditions at Owens Lake. The full implementation measures are expected to occur by January 2007.
In the vicinity of Ridgecrest, the Indian Wells Valley Water District has been involved in a cooperative study and project to alleviate declining groundwater levels and to manage water quality problems. The proposal is evaluating the availability and use of imported water for groundwater recharge. Studies are being conducted to determine where recharge would be most feasible. Additional studies will also attempt to determine the age and source of deep groundwater aquifers, which may contain higher levels of minerals and potential water quality issues. 

### Accomplishments The region has developed solutions to two major water issues during the past 10 years, which are the overuse of the Mojave River Valley groundwater basin and changes to water diversions from the Owens River/Mono Basin by the city of Los Angeles. The Mojave River groundwater basin was in overdraft since the early 1950s, which led to court adjudication in 1996 and theappointment of the Mojave Water Agency as the basin watermaster (see Box 3-2). The Los Angeles Department of Water and Power is involved with many restoration projects for the Owens River and Mono Basin. In 1993, LADWP began final flow releases to restore Mono Lake to a water surface elevation of 6,392 feet. By 2003, Mono Lake elevation had reached 6,382, a level where LADWP can export 16,000 acre-feet per year. LADWP has developed plans to help ranchers manage grazing practices in the Crowley Lake tributary area. The Owens Gorge Rewatering Project and the Lower Owens River Project are two other significant restoration programs being implemented by LADWP to restore the river after 50 years of dewatering.

In 1994, Mojave Water Agency completed its Morongo Basin project, which is a 70-mile pipeline from the East Branch of the SWP to the Morongo Basin. This system has a capacity of 100 cubic feet per second or nearly 72,300 acre-feet per year to the Mojave River, and then reduces to a capacity of 15,700 acre-feet per year to Morongo Basin and Johnson Valley. The pipeline allows MWA to bring SWP water into part of its almost 5,000-square-mile service area. MWA has been delivering about 3,500 acre-feet per year to the Hi-Desert Water District since completion of the Morongo Basin Pipeline. In 1997, MWA began construction of another 61-mile Mojave River Pipeline with 67,900 acre-feet per year capacity to bring imported water to the Barstow area and neighboring communities downstream to the Newberry Springs area. This 61-mile pipeline has been built to a recharge facility along the river near the community of Daggett. Recharge facilities have also been built along the river near the communities of Hodge and Lenwood. When completed, the final reaches of the pipeline will extend to a groundwater recharge facility in the Newberry Springs area.
Mojave Water Agency has entered into a creative multiyear groundwater banking and exchange agreement with the Solano County Water Agency in northern California. During any wet year, SCWA can bank up to 10,000 acre-feet of its annual SWP water in MWA’s groundwater basin, not to exceed a total balance of 20,000 acre-feet. During droughts, SCWA can take part of MWA’s SWP water by exchange, using theNorth Bay Aqueduct to divert the water from the SacramentoSan Joaquin Delta. MWA has developed the ability to store9 10 **Chapter 10** South Lahontan Hydrologic Region California Water Plan Update 2005



## Box 10-2 Mojave River Adjudication
The Mojave River Groundwater basin has experienced overdraft since the early 1950s, with the largest increase in groundwater overdraft occurring in the 1980s. In January 1996, the Riverside County Superior Court issued a final ruling on the adjudication of this basin (the case having been transferred out of San Bernardino County). The court ruling confirmed that the area had been in overdraft for decades, and directed that the Mojave Water Agency must alleviate overdraft through conservation and the purchase of supplemental water. MWA was appointed as the basin watermaster. Some parties challenged the Stipulated Judgment in the 4th District Court of Appeal, which partially overturned the Superior Court’s decision. The MWA petitioned the California Supreme Court to accept review of the Court of Appeal’s decision, which resulted in the case being heard by the California Supreme Court in August 2000. The higher court affirmed the stipulated judgment with regard to the parties involved, but determined that some of the appellants held overlying water rights that are not subject to the judgment. Consequently, this final judgment has been implemented in the Mojave Basin Area.

The adjudication stipulated that any party pumping more than 10 acre-feet per year of groundwater must become a party to the judgment and be bound by it. The judgment stated that each party has a right to its base annual groundwater production, which was determined from the highest usage between 1986 and 1990. The judgment also required the watermaster to initially reduce this amount by at least 5 percent each year for four years as one way to achieve a physical solution to the longstanding overdraft. Any party exceeding its annual allotment must purchase replenishment water from MWA or from other parties to the judgment. If there is still overdraft after the end of the first five years of the judgment, water use in overdrafted subareas will be further reduced. The judgment recognized five basin subareas and required that if an upstream subarea does not meet its water obligation to a downstream subarea, then the upstream area must pay for supplemental water. more imported supplies in the Mojave River Basin at MWA’sRock Springs groundwater recharge facility and is consideri ng more recharge facilities in other areas. Several other districts are also studying potential groundwater recharge and exchange projects. Funds from loan and grant programs, especially for drought relief, will play an important role in the continued development of water projects for this region.


## Relationship with Other Regions While most of Mojave Water Agency’s service area is in the South Lahontan region, a portion of its service area does extend into the Colorado River Hydrologic Region (Lucerne and Johnson valleys and the Morongo Basin). This includes the community of Yucca Valley, which has an allocation for up to 7,200 acre-feet of MWA’s surface water from the SWP.
As described in previous sections, imported State Water Project water is used to recharge groundwater supplies in the Mojave River Valley basins. Some of these surface water and groundwater supplies are also exported from the Owens and Mono portions of South Lahontan Hydrologic Region to the South Coast Hydrologic Region by the Los Angeles Department of Water and Power, using the Los Angeles Aqueduct. Recent exports through these facilities to the South Coast region were 442,000 acre-feet in 1998, 294,000 acre-feet in year 2000, and 272,000 acre-feet in 2001.


## Looking to the Future To address the needs of expanding urban areas in the southernportion of the region, many water districts have taken a proactive approach to the water reliability problems by initiating studies and projects that could provide partial or complete solutions. These include water conservation programs, water recycling projects, groundwater exchanges and recovery,water marketing, and other water supply augmentation strategies. Agricultural practices and water uses in rural areas are anticipated to remain at current levels for the near future.


## Regional Planning Mojave Water Agency is updating its previous 1994 Regional Water Management Plan, which will allow it to identify and prioritize future water supply projects. This update process began in 2002 and is expected to be completed in 2005. As an example of regional planning, MWA has initiated aCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 10 10 demonstration project in the Oro Grande Wash south of the city of Victorville to evaluate the effectiveness of off-river artificialgroundwater recharge using State Water Project water. The project site is located several miles away from the main stem of the Mojave River and intends to supply imported surface water for groundwater recharge. When needed, the local water purveyors would subsequently pump this stored groundwater for use in the rapidly growing urban areas. This project is the first of several off-river recharge projects that the agency considers as the next major phase in water supply infrastructure development.

With a growing population and increasing demands on the limited supplies of fresh water for its service area, Victor Valley Wastewater Reclamation Authority (VVWRA) has been planninga program with new facilities that would recycle millions of gall ons of wastewater daily. The current wastewater flows are about 9 MGD from more than 100,000 residents, and are expected to increase to more than 18.7 MGD by the year 2020. In 1997, the VVWRA completed a feasibility study that projected population growth and wastewater treatment requirements, and identified potential reclamation strategies and costs through 2020. These strategies included potential uses of the fully-treated effluent for beneficial purposes such as landscape irrigation and industrial process water. In 2000, VVWRA adopted amendments to the plan, which projected future wastewater flows within it’s service area with greater accuracy, and recommended the completion of four sub-regional wastewater reclamation facilities by the year 2010. In 2002 VVWRA also completed an interim expansion of its treatment plant to accommodate wasteflows of up to 11 million gallons-per-day.
The VVWRA Board of Commissioners also approved a draft policy to sell the recycled water at the current river discharge location to stipulated parties from the Mojave Adjudication, and held a public hearing on the policy in 2001. Under the proposed policy, recycled water would be sold and credited to individual parties for use in meeting makeup water or replacement water requirements as specified by the Mojave River adjudication. However, the board has delayed approval of this proposed policy until legal challenges to the Mojave Adjudication are settled by the Superior Court.
The Antelope Valley Water Group (AVWG) was formed in 1991 to provide coordination among valley water agencies and other planning groups. AVWG members include the cities of Palmdale and Lancaster, Edwards Air Force Base, AVEK, Antelope Valley United Water Purveyors Association, Los Angeles County Waterworks Districts, PWD, Rosamond Community Services District, and Los Angeles County. AVWG then completed the Antelope Valley Water Resource Study in 1995 to address regional water management issues. That study evaluated the valley’s existing and future water supplies from groundwater, the SWP, Littlerock Reservoir, and recycling, and then compared those supplies with projected water demands. The study concluded that there is a low level of water supply reliability in the study area, and concluded that full 1998 waterdemands could only be met half of the time without overdrafti ng groundwater resources. The report recommended water conservation, recycling, and conjunctive use as strategies to reduce expected water shortages, and identified three potential sites (two on Amargosa Creek and one on Littlerock Creek) with high potential as groundwater recharge spreading ponds. The study also identified several potential groundwater injection sites within existing Los Angeles County Waterworks and PWD municipal well fields, and treated SWP water was identified as a potential recharge source. AVWG agencies are now developingindividual programs and projects based on the recommendations from that 1995 water resource study

. In 2001, Palmdale Water District adopted a water facilities master plan for its service area, which updated previous 1989 and 1996 master plans. PWD relies on three water sources: Littlerock Reservoir, local groundwater, and SWP surface water.The master plan highlights PWD’s desire to maintain the capability to obtain 40 percent of its water supply from groundwater.However, because declining groundwater levels are an ongoing concern in the Palmdale area, there is uncertainty about whether the groundwater basin’s perennial yield could support the desired level of pumping. In addition, this plan indicated that existing supplies would not be insufficient to meet demands in drought periods, and projected possible water supply shortfalls during normal years by 2010.
To help meet future demands, the PWD plan recommended building up to six new wells and modifications to four existing cased wells, so that they could be used to help meet potable water demands. The Draft Environmental Impact Report for the plan identified a continuing decline in groundwater levels as an unavoidable effect from building new wells and pumping additional groundwater, as desired to maintain groundwater as 40 percent of PWD’s total supply. Mitigation measures have been developed which recommend more water conservation, drought-year reductions in water demands, more conjunctive use programs, the acquisition of additional SWP surface water,participation in water marketing and transfers, and the expansion of available uses for recycled water

. In 2002, the Quartz Hill Water District constructed six wellsin order to develop the capability to participate in future conjunctive use projects. Only four of these wells were equipped11 10 **Chapter 10** South Lahontan Hydrologic Region California Water Plan Update 2005

with groundwater pumps because the water yield from theother two wells was too small. Quartz Hill WD is also plann ing to add groundwater injection equipment to some of it’s wells, so that recharge of the groundwater basin can occur whenever surplus SWP water supplies are available.



## Water Portfolios for Water **Y ears 1998, 2000, and 2001**  Water Year 1998 Water year 1998 was a wet year for this region, with annual precipitation at 188 percent of normal, while the statewide annual precipitation was 171 percent of average. The reservoirs in the region increased storage by about 72,000 acre-feet as a result of the additional rainfall and runoff, but the regions groundwater basins were drawn down by about 226,000 acre-feet. The expanding urban developments in the southern portion of this region have become dependent on the use of groundwater to meet water demands, because significant surface water resources and facilities do not exist. As a result more groundwater is pumped and used annually than can be recharged, even during the wetter years.

The primary agricultural water use in the region is irrigation of alfalfa and pasture grass for raising beef. Smaller amounts of land are dedicated to truck crops, such as carrots and onions, and still less is used for grain crops and orchards. As shown in Table 10-3 the total agricultural applied water use for 1998 in this region was 280,600 acre-feet, which is about 48 percent of the total developed use of 590,200 acre-feet. Agricultural water use in 1998 was less than in years 2000 and 2001 because the significant amount of rainfall in this wet year reduced the need for irrigation.

Total urban applied water use for the region was 211,200 acrefeet in 1998, which represents about 36 percent of all water use. The wet winter of 1998 also reduced the amount of urban water use compared to years 2000 and 2001 (as shown in Table 10- 3), because this category also includes outdoor landscape, parks and recreation facilities which generally require less water in a wetter year. Total environmental water use for this region was 98,400 acre-feet, primarily for uses related to the preservation of Mono Lake and Owens River flows.
In 1998 about 442,000 acre-feet of surface water was exported from this region to the South Coast through the Los Angeles Aqueduct, as a result of the wet winter and abundant water supplies. SWP water deliveries into the South Lahontan regionwere 73,000 acre-feet from the California Aqueduct. An additional 844,000 acre-feet of SWP surface water flowed through this region in the California Aqueduct, passing from the Tulare Lake region for deliveries to the South Coast region. These regional imports and exports are summarizedon the regional map in Figure 10-1.



### Water Year 2000 Year 2000 was dry in the South Lahontan region with annual precipitation at 66 percent of average, while the state as a whole received near normal rainfall. The lack of rainfall increased the need to apply water to crops, resulting in a total agricultural applied water use of about 361,000 acre-feet, which is about 50 percent of the total developed use of 718,600 acre-feet. As shown in Table 10-3, urban water use also increased in year 2000 (compared to 1998), and the 269,000 acre-feet of urban use represented about 37 percent of total applied water uses. Dedicated environmental water uses in the region declined slightly in year 2000 compared to 1998, and represent about 13 of the total applied water uses.
During year 2000, total storage in the surface reservoirs decreased by 8,000 acre-feet as more water was releasedfor use than was available for storage. Net groundwater storage declined by roughly 294,000 acre-feet, as more water is pumped to meet demands in a dryer water year. Only 294,000 acre-feet of surface water was diverted from the South Lahontan region through the LA Aqueduct to the South Coast region, which is significantly less than the 1998 amount. However more SWP water from the California Aqueduct flowed through the region, with 108,000 acre-feet diverted to meet local uses and 1,401,000 passed to the South Coast region (see Figure 10-1).



### Water Year 2001 Year 2001 produced slightly below normal water supply conditions in the South Lahontan region with annual precipitation at 91 percent of average. For comparison, statewide average precipitation in year 2001 was only 72 percent of normal. Because the South Lahontan region is a relatively arid part of the State (average annual precipitation is less than 10 inches), a single storm event can significantly alterthe regional average in comparison to statewide precipitation. The reduced amounts of rainfall in other regions of the State resulted in lower SWP deliveries to water contractors, and SWP imports to the South Lahontan region were about 82,000 acre-feet. As shown in Table 10-3, urban, agricultural and environmental water uses were all slightly less than in year 2000, and accounted for roughly the same percentages of the total developed water supply.California Water Plan Update 2005

**Volume 3** Regional Reports 12 10 About 272,000 acre-feet of surface water was exported through the L.A. Aqueduct to the South Coast region in 2001, which is slightly less than in year 2000. An additional 983,000 acre-feet of SWP surface water flowed through this region in the California Aqueduct, passing from the Tulare Lake region for deliveries in the South Coast region. As shown in Table 10-1, the region’s surface reservoir storage in 2001 remained nearly the same as in year 2000, but the amount of groundwater in storage continued to decline, by 299,000 acre-feet during this year.
A more detailed tabulation of the developed urban, agricultural and environmental water uses and water depletion is presented in Table 10-3. This table also provides details about the sources of the developed water supplies, which include surface water, groundwater and some SWP water imports from other regions. The three water portfolio data sets included in Table 10-3 and the companion water portfolio flow diagrams (Figures 10-4 and 10-5 ) provide more detailed information about how the available water is routed, distributed and used throughout this region.



## Selected References 2002 California 305(b) Report on Water Quality, State Water Resources Control Board A ntelope Valley Water Resource Study by Kennedy/Jenks Consultants Engineers and Scientists for Antelope Valley Water Group, November 1995 C alifornia’s Groundwater Bulletin 118-05, Update 2003, California Department of Water Resources D raft Environmental Impact Report and Statement for the West Mojave Plan, Bureau of Land Management, May 2003 L ancaster Water Reclamation Plant 2020 Plan EIR, District 14, Antelope Valley Los Angeles County, September 2003 N onpoint Source Program Strategy and Implementation Plan, 1998-2013, State Water Resources Control Board, California Coastal Commission, January 2000 Mojave Water Agency Regional Water Management Plan, June 1994, Bookman-Edmonston Engineering, Inc., Glendale California P almdale Water District Final Water System Master Plan Update, March 2001, Montgomery Watson S trategic Plan, State Water Resources Control Board, Regional Water Quality Control Boards, November 15, 2001 T echnical Memorandum, Establishing Objectives and Standards based on Existing Management Framework Owens Lake Groundwater Evaluation, Inyo County, CA, December 1998 T echnical Memorandum, Description of Existing Investigations and Data Relevant to the Owens Lake Groundwater Evaluation, Inyo County CA, Camp, Dresser & McKee, March 29, 1999 W

ater Quality Control Plan, Regional Water Quality Control Board W atershed Management Initiative Chapter, Regional Water

Quality Control13 10 **Chapter 10** South Lahontan Hydrologic Region California Water Plan Update 2005



# Water Portfolios

South Lahontan Hydrologic RegionCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 14 10 **Table 10-3 South Lahontan region water portfolio (TAF)** 

ID South Lahontan South Lahontan South Lahontan Number: Flow Diagram Component (see legend) 1998 2000 2001 1 Colorado River Deliveries

- - - 2 Total Desalination

- - - 3 Water from Refineries

- - - 4a Inflow From Oregon

- - - b Inflow From Mexico

- - - 5 Precipitation 20,409.3 7,476.1 9,740.9 6a Runoff - Natural b Runoff - Incidental 7 Total Groundwater Natural Recharge 8 Groundwater Subsurface Inflow N/A 9 Local Deliveries 56.6 58.1 46.8 10 Local Imports

- - - 11a Central Valley Project :: Base Deliveries

- - - b Central Valley Project :: Project Deliveries

- - - 12 Other Federal Deliveries

- - - 13 State Water Project Deliveries 73.1 108.0 81.9 14a Water Transfers - Regional

- - - b Water Transfers - Imported

- - - 15a Releases for Delta Outflow - CVP b Releases for Delta Outflow - SWP c Instream Flow Applied Water 98.4 88.8 78.4 16 Environmental Water Account Releases

- - - 17a Conveyance Return Flows to Developed Supply - Urban

- - - b Conveyance Return Flows to Developed Supply - Ag

- - - c Conveyance Return Flows to Developed Supply - Managed Wetlands

- - - 18a Conveyance Seepage - Urban

- - - b Conveyance Seepage - Ag

- - - c Conveyance Seepage - Managed Wetlands

- - - 19a Recycled Water - Agriculture

- - - b Recycled Water - Urban 28.0 29.0 29.5 c Recycled Water - Groundwater

- - - 20a Return Flow to Developed Supply - Ag

- - - b Return Flow to Developed Supply - Wetlands

- - - c Return Flow to Developed Supply - Urban

- - - 21a Deep Percolation of Applied Water - Ag 35.4 44.2 42.1 b Deep Percolation of Applied Water - Wetlands

- - - c Deep Percolation of Applied Water - Urban 66.1 83.5 75.6 22a Reuse of Return Flows within Region - Ag

- - - b Reuse of Return Flows within Region - Wetlands, Instream, W&S 18.6 21.4 20.6 24a Return Flow for Delta Outflow - Ag

- - - b Return Flow for Delta Outflow - Wetlands, Instream, W&S

- - - c Return Flow for Delta Outflow - Urban Wastewater

- - - 25 Direct Diversions 26 Surface Water in Storage - Beg of Yr 329.4 326.2 317.8 27 Groundwater Extractions - Banked

- - - 28 Groundwater Extractions - Adjudicated 61.8 61.8 61.8 29 Groundwater Extractions - Unadjudicated 272.3 372.9 360.5 23 Groundwater Subsurface Outflow N/A N/A N/A 30 Surface Water Storage - End of Yr 401.5 317.8 316.5 31 Groundwater Recharge-Contract Banking

- - - 32 Groundwater Recharge-Adjudicated Basins

- - - 33 Groundwater Recharge-Unadjudicated Basins

- - - 34a Evaporation and Evapotranspiration from Native Vegetation b Evaporation and Evapotranspiration from Unirrigated Ag 35a Evaporation from Lakes 162.4 163.7 163.4 b Evaporation from Reservoirs 45.1 45.1 42.1 36 Ag Effective Precipitation on Irrigated Lands 33.5 9.9 7.2 37 Agricultural Water Use 280.6 361.0 344.0 38 Managed Wetlands Water Use

- - - 39a Urban Residential Use - Single Family - Interior 74.5 109.0 100.8 b Urban Residential Use - Single Family - Exterior 55.8 68.6 68.4 c Urban Residential Use - Multi-family - Interior 11.9 28.0 12.7 d Urban Residential Use - Multi-family - Exterior 7.1 8.6 6.9 40 Urban Commercial Use 27.8 19.0 20.1 41 Urban Industrial Use 8.1 4.7 5.6 42 Urban Large Landscape 8.4 6.6 5.3 43 Urban Energy Production 6.3 6.3 6.3 44 Instream Flow 79.8 67.4 57.8 45 Required Delta Outflow

- - - 46 Wild and Scenic Rivers

- - - 47a Evapotranspiration of Applied Water - Ag 187.8 237.7 235 b Evapotranspiration of Applied Water - Managed Wetlands

- - - c Evapotranspiration of Applied Water - Urban 71.282 83.791 80.591 48 Evaporation and Evapotranspiration from Urban Wastewater

- - - 49 Return Flows Evaporation and Evapotranspiration - Ag 5.7 7.3 6.7 50 Urban Waste Water Produced 29.34 36.14 33.34 51a Conveyance Evaporation and Evapotranspiration - Urban 8.51 10.6 8.81 b Conveyance Evaporation and Evapotranspiration - Ag

- - - c Conveyance Evaporation and Evapotranspiration - Managed Wetlands

- - - d Conveyance Outflow to Mexico 52a Return Flows to Salt Sink - Ag 51.7 65.4 60 b Return Flows to Salt Sink - Urban 58.89 84.41 66.1 c Return Flows to Salt Sink - Wetlands

- - - 53 Remaining Natural Runoff - Flows to Salt Sink 79.8 67.4 57.8 54a Outflow to Nevada

- - - b Outflow to Oregon

- - - c Outflow to Mexico

- - - 55 Regional Imports 917.7 1,509.7 1,065.7 56 Regional Exports 1286 1695.0 1255 59 Groundwater Net Change in Storage -226.2 -294.1 -299.0 60 Surface Water Net Change in Storage 72.1 -8.4 -1.3

61 Surface Water Total Available Storage 458.9 458.9 458.9
Inflows Outflows Green number signifies included in summary boxes**Chapter 10** South Lahontan Region 15 10 **Volume 3**  Regional Reports California Wa ter Plan Update 200 516 10 **Volume 3**  Regional Reports **Chapter 10** South Lahontan Region California Wa ter Plan Update 200 5

## Chapter 11 Colorado River Hydrologic Region 

# Volume 3i11 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005 

# Chapter 11 Colorado River Hydrologic Region

Contents Chapter 11 Colorado River Hydrologic Region ........................................................................................................11-1 Setting .............................. 11-1 Climate ............................. 11-1 Population ........................ 11-1 Land Use .......................... 11-1 Water Supply and Use ....... 11-4 State of the Region .......... 11-11 Challenges ................ 11-11 Accomplishments ....... 11-14 Relationship with Other Regions .......................................................................................................................11-14 Looking to the Future ....... 11-16 Water Portfolios for Water Years 1998, 2000, and 2001 ...................................................................................11-17 Selected References ......... 11-20



## Box Box 11-1 Acronyms Used in the Colorado River Regional Report ..............................................................................11-2 Box 11-2 Salton Sea Description ..........................................................................................................................11-11 Box 11-3 Salton Sea Ecosystem ............................................................................................................................11-12 Box 11-4 Key Elements of Califor nia’s Colorado River Quantification Settlement Agreement .....................................11-16



## Figures Figure 11-1 Colorado River Hydrologic Region (map) ..............................................................................................11-ii Figure 11-2 Colorado River Hydrologic Region population .......................................................................................11-3 Figure 11-3 Colorado River region water balance for water years 1998, 2000, 2001 (2 bar charts) ..........................11-6 Figure 11-4 Colorado River region - illustrated water flow diagram ........................................................................11-25 Figure 11-5 Colorado River region - schematic flow diagram .................................................................................11-26



## Tables Table 11-1 Key elements of the Law of the River .......................................................................................................11-5 T able 11-2 Annual apportionment of use of Colorado River water (interstate/international) ........................................11-7 T able 11-3 Annual apportionment of water from the Colorado River mainstream to the lower basin states ...................11-7 T able 11-4 Annual intrastate apportionment of water from the Colorado River mainstream within California under the Seven Party Agreement ..... 11-8 T able 11-5 QSA for Priorities 1-3 annual use of Colorado River water by Califor nia agencies ....................................11-8 T able 11-6 SWP contractors in the Colorado River region ........................................................................................11-9 T able 11-7 Existing Colorado River region water conservation actions/agreements since 1980 .................................11-15 T able 11-8 Colorado River Hydrologic Region water balance summary ...................................................................11-18 T able 11-9 Colorado River region water use and distribution of dedicated supplies ..................................................11-19 T able 11-10 Colorado River region water portfolios ...............................................................................................11-24**Volume 3** Regional Reports California Water Plan Update 2005

**Some Statistics** Area - 19,962 square miles (12.6% of State) Average annual precipitation - 5.7 inches Year 2000 population - 606,535 2030 population projection -1,166,550 Total reservoir storage capacity - 620 TAF 2000 irrigated crop area - 731,890 acres .

.

.

.

.

.

Flow in TAF
1998 4,986 2000 5,349 2001 5,197 **Colorado River** Flow in TAF
1998 1,081 2000 1,296 2001 1,250 **South Coast Region** Colorado River Aqueduct **Figure 11-1 Colorado River Hydrologic Region**

The Colorado River Hydrologic Region is in the southeastern corner of California and includes the Imperial and Coachella valleys, known for year-round agricultural production. Arrows indicate annual flow s entering and leaving the region for water years 1998, 2000, a nd 2001. SAN BERNARDINO

RIVERSIDE

SAN DIEGO IMPERIAL

Inflow From Mexico 1998 182 2000 166 2001 155111 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005



# Chapter 11 Colorado River Hydrologic Region

to 90 percent of the maximum possible sunshine each year,the highest value in the United States. Winter maximum temperatures are mild, but summer conditions are generally very hot, with more than 100 days with temperatures of over 100 degrees Fahrenheit each year in the Imperial Valley.


## Population In 2000, the population for the region was about 606,000, which represented an increase of 31 percent from the 1990 population. More than half of the region’s populationresides in the Coachella Valley, where significant urbanizat ion has occurred. Most of the remaining population is in the Imperial Valley and in the corridor between the cities of Yucca Valley and Twenty-nine Palms along Highway 62. From 2000 to 2030, the California Department of Finance projects that the regional population will almost double to 1,166,550 people. Figure 11-2 provides a graphical depiction of the Colorado River region’s total population from 1960 through 2000, with projections to 2030.



## Land Use The region is a land of unequalled agricultural bounty with agrowing urban sector, and large expanses of open, wild terr ain. The U.S. Bureau of Land Management (BLM) administers a large portion of the region’s land, but many other entities also oversee significant areas. (See Box 11-1 for acronyms used in this chapter.)
Famous parks in the region include Joshua Tree National Park, the Mojave National Scenic Preserve, Anza-Borrego Desert State Park, and the Salton Sea and the Picacho state recreation areas. There are also several areas set aside for preservation or other land management purposes, including national recreation and wilderness areas, wildlife refuges, Indian tribal reservations and U.S. Navy facilities. 

## Setting The Colorado River hydrologic region covers the southeast portion of California and contains 12 percent of the state’s land area. The Colorado River forms most of the region’s eastern boundary and the international boundary with Mexico forms its southern boundary (Figure 11-1 is a map and table of statistics that describe this region). The region includes all of Imperial County, about the eastern one-fourth of San Diego County, the eastern two-thirds of Riverside County, and the southeastern one-third of San Bernardino County. Ithas a variety of arid desert terrain that includes many bowlshaped valleys, broad alluvial fans, sandy washes, and hills and mountains.

The Colorado River region includes a large portion of the Mojave Desert, primarily in that part of the region in San Bernardino County and eastern Riverside County. The area to the east and south of the Mojave Desert is a portion of the Sonoran Desert. Elevations in the region generally range from 1,000 to 3,000 feet in the Mojave Desert, to less than 1,000 feet along the Colorado River. The lowest areas in this region are more than 200 feet below mean sea level in the Coachella and Imperial Valleys. Mountain peaks attain elevations of 6,000 to 7,000 feet. Many of these arid valleys contain playas (dry lake beds), some of which are quite large. Bristol Dry Lake, near the Mojave National Preserve, is a playa that covers more than 50 square miles.



## Climate Nearly all of the Colorado River region has a subtropical desert climate with hot summers and generally mild winters. Average annual rainfall is very low and precipitation ranges between 3 to 6 inches per year, most of which occurs in the winter months. However, summer storms do occur and can generate significant rainfall in some years. Clear and sunny conditions typically prevail, and the region receives from 85California Water Plan Update 2005

**Volume 3** Regional Reports 211 Despite the arid conditions, significant areas of agricultural and urban land use exist in the region. Agriculture is the most prominent land use, with more than $1.5 billion of agricultural commodities produced in the region each year. Over 600,000 acres of land are farmed each year. The largest agricultural area occurs in the Imperial Valley where over 450,000 acres of land are farmed annually. More than 93,000 acres are farmed in the Palo Verde Valley, followed by 60,000 acres in the Coachella Valley. Smaller, but equally important agricultural operations also exist in the Bard and Mojave valleys. Despite its arid conditions, the region produces more than $1.5 billion of agricultural commodities annually. The largest water body in the Colorado River region is the Salton Sea (in photo background), a saline body of water about 50 feet deep. (DWR photo)



## Box 11-1 Acronyms Used in the Colorado River Regional Report

BWD Bard Water District CVWD Coachella Valley Water District DFG California Department of Fish and Game DW A Desert Water Agency DWR California Department of Water Resources IID Imperial Irrigation District L CR MSCP L ower C olorado River Multi-Species Conservation Program maf million acre-feet MWD Metropolitan Water District of Southern California PVID Palo Verde Irrigation District QSA Quantification Settlement Agreement of 2003 SGPW A San Gorgonio Pass Water Agency SDCW A San Diego County Water Authority SSAM Salton Sea Accounting Model SWP State Water Project USBR US Bureau of Reclamation USFS US Fish and Wildlife Service311 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

A wide variety of crops are planted and harvested in the region, some of which are grown only during specifi c times of the year. In terms of acres, alfalfa is the leading crop produced in the Colorado River region. Almost 250,000 acres were grown in 2000, of which 180,000 acres were in the Imperial Valley. Although constrained by summer climate, winter and spring vegetables, which include carrots, broccoli, lettuce, onions, and melons, rank second in overall acres. Of the150,000 acres harvested, almost 100,000 acres of the vegetables harvested in 2000 came from the Imperial Valley.
The Coachella and Bard valleys are noteworthy for citrus and subtropical fruit production, especially dates. The table grape industry is also well established in the Coachella Valley.
The cattle industry in the Imperial Valley is extremely important to the region’s $1 billion per year agricultural production. In 2001, the cattle industry, with a value of $243 million, ranked as the third highest-value commodity produced in the Imperial Valley. Vegetable and melon crops were ranked fi rst with a value of $403 million, while fi eld crops were the second-ranked commodity worth $285 million. Other important crops grown in the Colorado River region include wheat, sugar beets, and Sudan grass. Although less cotton is grown now than at its peak in the early 1980s, some cotton is still grown, mostly in the Palo Verde Valley.
Multiple-cropping is the prevalent agricultural practice in the Imperial, Palo Verde, Coachella, and Bard valleys. During2000, it was estimated that over 100,000 acres were doublecropped in the region.

Urban land uses and acreage are expanding, and co-exist with agriculture in the region. In the northern Coachella Valley, urbanization continues to expand between the Cities of Palm Springs and Indio. Other growing cities in the Coachella Valley include Palm Desert, Rancho Mirage, and La Quinta. This corridor is characterized by the presence of numerous extensively landscaped residential developments, expansion of local business and consumer service centers, construction of luxury hotels and resort properties, and the operation of over 100 private and public golf courses. Upscale commercial and residential expansion, which has been under way for several decades, is continuing at a robust pace. This expansion supports the region’s recreation and tourism industry and its growing number of wealthy retirees and part-time residents. 

### Figure 11-2 Colorado River Hydrologic Region population

0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000

1960 1970 1980 1990 2000 2010 2020 2030

Data from California Department of Finance provide decadal population from 1960 to 2000 and population projection for 2030 for Colorado River region.California Water Plan Update 2005

**Volume 3** Regional Reports 411Although smaller in scale, the region’s urban areas in the corridor between the cities of El Centro and Imperial and around the city of Calexico have also been expanding. Business and consumer services there support the population of the Imperial Valley and the neighboring Mexicali Valley. In 2001 a third port of entry across the border with Mexico opened, which generates increased traffic resulting from NAFTA-related business activity.
In the Imperial and Palo Verde valleys and the southern one-half of the Coachella Valley, small to moderately sizedcities and communities provide support for the surroundi ng agricultural and non-agricultural activities. There arealso numerous single-family residential dwellings scatt ered throughout the region. Many of the business and industrial sectors in the cities of Blythe, Brawley and Indio provide services that also support this type of lifestyle.


## Water Supply and Use About 85 percent of the region’s urban and agricultural water supply comes from surface water deliveries from the Colorado River. Water from the river is delivered into the region through the All-American and Coachella canals, local diversions, and the Colorado River Aqueduct by means of an exchange for State Water Project (SWP) water. The Colorado River is an interstate and international river whose use is apportioned among the seven Colorado River Basin states and Mexico by a complex body of statutes, decrees, and court decisions known collectively as the “Law of the River” (Table 11-1). Local surface water, groundwater, and the SWP provide the remainder of water to the region. In addition, many of the alluvial valleys in the region are underlain by groundwater aquifers that are the sole source of water for local communities. There are other alluvial valleys that have poor quality water that is not suitablefor potable use. Figure 11-3 presents two bar charts that summarize all of the dedicated and developed urban, agricultural and environmental water uses and the sources of supply within this hydrologic region for years 1998, 2000 and 2001.
In California, the Seven Party Agreement of 1931 established local agencies’ apportionments of Colorado River water, whichwere further defined in the Quantification Settlement Agreement of 2003 (Tables 11-2, 11-3, 11-4, and Table 11-5). The Secretary of the Interior apportions water to California water users according to the Seven Party and the Quantification Settlement Agreement (QSA). Water use that occurs within a state is charged to that state’s Colorado River apportionment. T hus, federal water uses, including uses associated with federal reserved rights (for example, tribal water rights), must also be accommodated within California’s basic apportionment of 4.4 million acre-feet per year plus one-half of any available surplus water.
Neither Coachella Valley Water District (CVWD) nor Desert Water Agency (DWA) has facilities to take direct delivery of SWP water. Instead, both agencies have entered into exchange agreements with the Metropolitan Water District of Southern California (MWD), whereby MWD releases water from its Colorado River Aqueduct into the Whitewater River for storage in the upper Coachella Valley groundwater basin. In exchange, MWD takes delivery of an equal amount of the agencies’ SWP water. San Gorgonio Pass Water Agency (SGPWA), which serves the Banning-Beaumont area, also lacks the facilities to take delivery of SWP water into the portion of its service area that is within the Colorado River region. However, SGPWA is currently delivering SWP waterinto the Santa Ana planning area of the South Coast Hydrologic Region. When Phase 2 of the East Branch Extension is eventually completed, SWP water will be delivered into the Colorado River Hydrologic Region. However, the California Department of Water Resources (DWR) is still developing plans for this Phase 2 extension project. (See Table 11-6 for SWP contractors in the Colorado River region.)

G roundwater provides about 7.5 percent of the region’s applied water supply in normal years and about 7.7 percentin drought years (DWR 1998). Groundwater storage capacity has been estimated for 40 of the region’s 57 groundwaterbasins and totals more than 175 million acre-feet. The largest water-using area in the region, the agricultural area of the Imperial Valley, is located mostly over a saline basin and therefore lacks usable groundwater.
In the Coachella Valley, groundwater levels began declining in the late 1920s due to extensive pumping. Since 1948, imported water supplies have been brought into this area from the Colorado River via the Coachella Canal. These surface water deliveries have enabled decreased pumping of groundwater in the southeastern portion of the valley and have thus helped recharge the basin. As a result, groundwater levels rose in this part of the valley until the 1980s. Since then the groundwater levels have again declined because of urban development and increased groundwater pumping.

L ocal water districts in the Coachella Valley have been working to address the decline in groundwater levels. The agreement between CVWD and DWA to bring SWP supplies into the511 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

Document Date Main Purpose Colorado River Compact 1922 The Upper Colorado River Basin and the Lower Colorado River Basin are each provided a basic apportionment of 7.5 maf annually of consumptive use. The Lower Basin is given the right to increase its consumptive use an additional 1 maf annually. Boulder Canyon Project Act 1928 Authorized USBR to construct Boulder (Hoover) Dam and the All-American Canal (including the Coachella Canal), and gave congressional consent to the Colorado River Compact. Provided that all users of Colorado River water stored in Lake Mead must enter into a contract with USBR for use of the water. California Limitation Act 1929 Limited California's share of the 7.5 maf annually appor- tioned to the Lower Basin to 4.4 maf annually, plus no more than half of any surplus waters. Seven Party Agreement 1931 An agreement among seven California water agencies/ districts to recommend to the Secretary of the Interior how to divide use of California's apportionment among the California water users. U.S. - Mexican Treaty 1944 Apportions Mexico a supply of 1.5 maf annually of Color ado River water except under surplus or extraordinary drought conditions. U.S. Supreme Court Decree in 1964 Apportions water from the mainstream of the Colorado River Arizona v. California, et al. among the Lower Division states. When the Secretary determines that 7.5 maf of mainstream water is available, it is apportioned 2.8 maf to Arizona, 4.4 maf to California, and 0.3 maf to Nevada. Quantifies tribal water rights for specified tribes, including 131,400 af for diversion in California. Colorado River Basin Project Act 1968 Authorized construction of the Central Arizona Project (CAP). Requires Secretary of the Interior to prepare long-range operating criteria for major Colorado River reservoirs. U.S. Supreme Court Decree in 1979, Quantifies Colorado River mainstream present perfected Arizona v. California, et al. 1984, rights in the Lower Basin states. supplemental decrees 2000 Quantification Settlement Agreement 2003 Complex package of agreements that, among other things, and Related Agreements further quantifies priorities established in the 1931 Seven- Party Agreements and enables specified water transfers in California. **Table 11-1 Key Elements of the Law of the River** California Water Plan Update 2005

**Volume 3** Regional Reports 611 **Figure 11-3 Colorado River region water balance for water years 1998, 2000, 2001**

0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000

1998 2000 2001Thousand Acre-Feet Managed Wetlands
Irrigated Agriculture

Urban

0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000

1998 2000 2001Thousand Acre-Feet Reuse & Recycle
Ground Water

State Project

Colorado Project Local Projects **Dedicated Water Supplies Applied Water Uses** 

Three years show a marked change in the amount and relative pro portions of water delivered to Colorado River region’s urban and agricultural sectors and water dedicated to the environment ( applied water, top chart), where the water came from, and how much water was reused among sectors (dedicated water supplies, botto m chart).711 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

**Table 11-2 Annual apportionment of use of Colorado River water**  (amounts represent consumptive use)

Upper Basin. Required to deliver 75 maf over a 10-year period m easured at Lee Ferry. (small portion of Arizona, Colorado, New Mexico, Utah, and Wyoming) 7.5 maf
Lower Basin 7.5 maf (portions of Arizona, California, Nevada, New Mexico, and Utah draining below Lee Ferry) plus 1 maf Republic of Mexico a 1.5 maf Total 17.5 maf b a. Plus 200 taf of surplus water, when available as determined by the United States. Water delivered to Mexico must meet specified salinity requirements. During an extraordinary drought or other cause resulting in reduced uses in the United States, deliveries to Mexico would be reduced proportionally with uses in the United States. b. The total volume is (7.5 + 7.5 + 1.0 + 1.5) = 17.5 maf/yr. Note that this total refers to all waters of the Colorado River System, which is defined as that portion of the Colorado River and its tributaries in the United States. 

### Interstate/International

Arizona 2.8 maf Nevada 0.3 maf California 4.4 maf Total 7.5 maf **Table 11-3 Annual Apportionment of Water from the Colorado River Mainstream to the Lower Basin**  **(amounts represent consumptive use)**California Water Plan Update 2005

**Volume 3** Regional Reports 811 **Table 11-4 Annual Intrastate Apportionment of Water from the Colorado River**  **Mainstream within California under the Seven Party Agreement c**  (amounts represent consumptive use) Priority 1 Palo Verde Irrigation District for beneficial use on 104,500 acres of lands within the Palo Verde Valley. Priority 2 USBR’s Yuma Project in California for beneficial use on up to 25,000 acres of lands within said Project Priority 3 Imperial Irrigation District and lands served from the All American Canal in Imperial and Coachella Valleys, and Palo Verde Irrigation District for use on 16,000 acres in the Lower Palo Verde Mesa. Priorities 1 through 3 collectively are not to exceed 3.85 maf/yr. The Seven Party Agreement did not quantify the division of this volume among the three priorities. Priorities 1-3 were further defined in the 2003 Quantification Settlement Agreement. Priority 4 Metropolitan Water District of Southern California (MWD) for coastal plain of Southern California – 550 taf/yr. Priority 5 An additional 550 taf/yr to MWD, and 112 taf/yr for the City and County of San Diego d

. Priority 6 e Imperial Irrigation District and lands served from the All-American Canal in Imperial and Coachella Valleys and Palo Verde Irrigation District for use on 16,000 acres in the Lower Palo Verde Mesa, for a total not to exceed 300 taf/yr. Total of Priorities 1 through 6 is 5.362 maf/yr. Priority 7 e All remaining water available for use in California, for agricultural use in California's Colorado River Basin. c. Indian tribes and miscellaneous present perfected right holders that are not encompassed in California’s Seven Party Agreement have the right to divert up to approximately 90 taf/year (equating to about 50 taf/yr of consumptive use) within California’s 4.4 maf/yr basic apportionment. Present consumptive use under these miscellaneous and Indian present perfected rights is approximately 15 taf/yr. d. Subsequent to execution of the Seven Party Agreement, MWD, SDCWA, and the city of San Diego executed a separate agreement transferring its apportionment to MWD. e. Under the 2003 Quantification Settlement Agreement, MWD (& S DCWA) gained access to water that may be available under Priority 6 and 7,

**Table 11-5 Quantification Settlement Agreement for Priorities 1- 3**  **Annual Use of Colorado River Water by California Agencies (amounts represent consumptive use)**  Priority 3 Approved Net Approved Net Quantification Consumptive Consumptive Use in 2003 a Use in 2003 a Priority 1,2, and 3b – Based on historical average use; deliveries above this amount in a given year will be deducted from MWD’s diversion (order) for the 420 taf 420.0 taf 420.0 taf next year; as agreed by MWD, IID, CVWD, and Secretary of the Interior (PVID & Yuma Project are not signatories to the QSA and are unaffected by it) Imperial Irrigation District 3,100 taf 2972.2 taf 2607.8 taf Coachella Valley Water District 330.0 taf 347.0 taf 424.0 taf Total Priority 1-3 Use 3,850 taf 3745.0 taf 3466.3 taf Remainder of 3.85 for use by MWD (& SDCWA) through priority rights and transfer agreements 0 taf 105.0 taf b 383.7 taf b a. Consumptive use is defined in the QSA as “the diversion of w ater from the main stream of the Colorado River, including water drawn from the main stream by underground pumping, net of measured and unmeasured return flows.” b. Includes miscellaneous present perfected rights, federal rights reserved, and decreed rights.911 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

valley was an important fi rst step. In 1984, another agreement was reached among CVWD, DWA, and MWD which allowed for the advanced deliveries of Colorado River water into the Coachella Valley during periods of high fl ows on the river. These supplies helped speed the pace of groundwater replenishment of the basin and provided water for future uses. However, groundwater levels still continue to decline in much of the basin.

U nder the 1984 agreement, MWD was also permitted to bank up to 600,000 acre-feet of surface water in the groundwaterbasin. When withdrawals are needed, MWD will use its Colorado River surface water along with CVWD’s SWP allocations, and CVWD will then use the banked groundwater until the volume stored under this agreement is gone.

In 2000, the estimated applied water demands for urban, agriculture, and the environment for the Colorado River region totaled 4,727,000 acre-feet. The estimated applied water demand for agriculture was 4,013,000 acre-feet, or about 85percent of the total. In accordance with the terms of the October 2003 QSA and related agreements, actual agricultural water use is expected to be reduced in future years.

Almost all of the agricultural demands in the region occur in the three major agricultural areas previously described, the Imperial, Palo Verde, and Coachella valleys. The Imperial Valley, with more than 500,000 acres of crops harvested each year (including double cropping), accounts for almost 70 percent of the total applied water demands for the region. In the Imperial and Palo Verde valleys, all agricultural demands are met with water from the Colorado River. In the Coachella Valley, agricultural demands are supplied by a combination of Colorado River surface water and groundwater.
Urban applied water demands account for about 15 percent of the overall totals for the Colorado River region. In 2000,total urban applied water was estimated to be 683,000 acrefeet. Most of these urban demands occur in the Coachella Valley, amounting to 527,000 acre-feet in year 2000 which is almost 80 percent of the total urban applied water for the region. Established housing and commercial uses have been augmented by large housing tracts with intensive landscaping, hotels, shopping centers, country clubs, golf courses, and polo fi elds. Landscape irrigation demands in the Coachella Valleyare large because of the expanse of turf grass and landscaping that have occurred in the past two decades.

Despite the availability of a reliable and inexpensive water supply, water districts and users are well aware of the importance of water conservation programs to effi ciently use and managewater. The agricultural growers in all of the districts do precision land forming for specifi c crops and use plastic and other mulches to reduce evapotranspiration and improve productivity. **Table 11-6 SWP contractors in the Colorado River region** 

Maximum

Annual Deliveries (taf)

23.1

38.1

75.8

17.3

153.3 SWP Deliveries in

2000 (taf)

42.3

58.2

11.2

0

111.7 Agency

Coachella Valley

W ater District
Desert Water Agency Mojave Water

Agency (a) San Gorgonio Pass W ater Agency Total SWP Delivery

a Maximum Annual Amounts include amounts for both the South Lahontan and Colorado River Regions; 7.3 taf of this amount is allocated to Colorado River Region.California Water Plan Update 2005

**Volume 3** Regional Reports 1011 For the past 50 years, the Imperial Irrigation District (IID), the region’s largest irrigation district, has implemented programs and completed projects designed to improve the efficiency of its water conveyance system. Under the 1988 IID/MWD Water Conservation Agreement and the Approval Agreement in 1989, 15 new projects were completed. These included the construction of three lateral interceptors serving more than 83,400 acres, the building of two regulatory reservoirs and four interceptor reservoirs, concrete-lining of nearly 200 miles of lateral canals, installation of new hardware and software to upgrade the existing telemetry control on the IID conveyance system, and completion of a new, state-of-the-art Water Control Center. These infrastructure upgrades complemented existing IID programs including farmer-initiated measures, canal lining, canal seepage recovery, and regulatory reservoirs.
In addition to the improvements to its water conveyance system, IID also implemented 13-Point and 21-Point Water Conservation Programs. IID also provides training and technical assistance to its agricultural customers through its Irrigation Management and Monitoring program. Its most valued service has been the dissem

i nation of information to farmers and irrigation personnel about methods to improve their irrigation operations. These programs actively promote the use of technical methods and instruments to improve irrigation efficiencies; including level basin drip systems,level basin laser-leveling, irrigation scheduling, portable pumpback and tailwater return systems, salinity assessment, and soil moisture sensors. IID also has a training program that it uses to provide growers with flow records, based on metering of the water delivered and tailwater runoff, for any particular irrigation site.

I n addition to the water supply savings in the IID/MWD agreem ent, improvements to IID’s water distribution system and other water conservation activities conserve more than 525,000 acre-feet of water annually. Of this amount, the IID estimates that 385,000 acre-feet of the savings are attributable to the efforts by its agricultural customers.
CVWD has also made important improvements to its water conv eyance system. Water is delivered to its agricultural customers through metered, underground pipelines. The conveyance system is computerized, which adds to the system’s efficiency. In addition to the infrastructure improvements, CVWD provides technical services in efficient irrigation management to its agricultural and residential customers.
The districts have also examined their water operation policies and procedures. This review has resulted in modifications in the delivery procedures that have improved efficiencies and assisted farmers in their irrigation scheduling. Palo Verde Irrigation District (PVID) has installed telemetry controls for more than 132 key control structures, which has improved the management of water in its canals. Most of thefields in the PVID and other district service areas have been laserleveled. Flattened fields help improve the uniform distribution of water. All deliveries to the PVID’s retail agricultural customers are measured, as are IID’s and CVWD’s.
PVID, IID, and CVWD, in cooperation with the University of California Cooperative Extension and DWR, have installed California Irrigation Management Information System (CIMIS) stations to collect the climatological data that agricultural water users need to estimate crop evapotranspiration of applied water (ETAW) and to develop irrigation schedules. Water users are made aware of improvements in irrigation managementand crop growing procedures through local water conservation boards and far m advisory boards.
To assist CVWD, PVID entered into an emergency six-month fallowing program in 2003. More than 16,417 acres of farmland were idled and the unused water, 41,000 acre-feet, was made available to CVWD.

I ID, PVID, and CVWD signed a Memorandum of Understanding Regarding Efficient Water Management Practices by Agricultural Water Suppliers in California. By signing the MOU, the districts demonstrated their intention to adopt and use agricultural water management plans that would improve agricultural water management and have beneficial environmental impacts within their service areas. IID’s 2002 Agricultural Water Management Plan has been endorsed by the Agricultural Water Management Council that oversees the MOU.

Growers in the major agricultural areas use the latest irrigation hardware and management techniques to increase both the efficiencies of their operations and crop yields. In the Imperial Valley, it is common to see drip, micro-sprinklers, and drip tape systems being used along with the traditional systems of furrow, basin, and hand-move sprinklers. Drip tape is most commonly used for high-market value crops such as vegetables. Drip and micro-sprinkler systems are commonlyused to irrigate the citrus and subtropical fruit orchards. Curr ently, less than 1 percent of the total orchard acreage, mainly date palms, is flood irrigated.
In the Coachella Valley most irrigation operations with vegetables and truck crops use drip tape and hand-move sprink lers. Some furrow irrigation is still used. Citrus and subtropical1111 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

fruit orchard irrigation is done with drip and micro-sprinklers; although flood or basin irrigation is still used for mature date palms. Almost all the vineyards are being irrigated by some type of drip system; only a very small portion still rely on furrow irrigation. The use of overhead sprinkler systems is a common sight in vineyards throughout the valley, where they are used for frost protection and the inducement of vine dormancy for earlier fruit-sets.
Although most of the water conservation has been directed to agriculture, water districts in the Coachella Valley provide technical assistance to the managers of large landscapedareas, such as golf courses, to evaluate and offer suggestions about irrigation hardware and operations. CVWD also provides loans to its retail customers for irrigation upgrades. Desert Water Agency offers classes in English and Spanish to homeowners, property managers, and government and school personnel on irrigation efficiency strategies and tools.
The largest water body in the region is the Salton Sea, a saline body of water about 50 feet deep. (See Box 11-2 Salton Sea Description.) Today’s surface water elevation is about229 feet below sea level. The Salton Sea has a concentration of total dissolved solids of about 46,000 mg/L, which is about 33 percent greater than that of ocean water. Most of the environmental water demands in the region are for the Sonny Bono Salton Sea National Wildlife Refuge, DFG Imperial Wildlife Area, wetland areas on the shore of the Salton Sea, and to maintain the viability of the sea under the QSA through 2017. To meet conditions for the IID/SDCWA transfer approved under the 2003 Colorado River QSA, from 2003 through 2017, IID will fallow enough ground to provide 800,000 acre-feet to the Salton Sea as mitigation for transferring water to San Diego. The Salton Sea ecosystem is considered a critical link on the international Pacific Flyway, providing wintering habitat for migratory birds, including some species whose diets are based exclusively on fish. The expected average annual inflows to the Salton Sea during the 25-year time frame of the California Water Plan Update 2005 are expected to be about 962,000 acre-feetper year, based on estimates using the Salton Sea Accounting Model (SSAM). This estimate has a standard deviation sensitivity range of about +/- 100,000 acre-feet per year.


## State of the Region Challenges Threatened or endangered fish species on the mainstem of the Colorado River include the Colorado pikeminnow, razorback sucker, humpback chub, and bonytail chub. Efforts to protect these fish may impact reservoir operations and streamflow in the mainstem and tributaries, which is critically important to California’s ability to store and divert Colorado River water supplies. Other species of concern in the basin include the bald eagle, Yuma clapper rail, black rail, southwestern willow flycatcher, yellow warbler, vermilion flycatcher, yellow-billed cuckoo, and Kanab ambersnail.

In 1993, the UFSWS published a draft recovery implementation plan for endangered fish in the upper Colorado River Basin. The draft plan included protecting instream flows, restoring habitat, reducing impacts of introduced fish andsportsfish management, conserving genetic integrity, monitori ng habitat and populations, and increasing public awareness of the role and importance of native fish.



## Box 11-2 Salton Sea Description
The present day Salton Sea was formed in 1905, when Colorado River water flowed through a break in an irrigation diversion structure that had been constructed along the U.S./Mexican border to divert the river’s flow to agricultural lands in the Imperial Valley. Until that break was repaired in 1907, the uncontrolled diversions of river water drained into the Salton Sink, a closed interior basin whose lowest point is about 278 feet below sea level.
Historically , the Colorado River’s course has changed several times. At times, the river discharged to the Gulf of California as it does today. At other times it flowed into the Salton Sink. Lake Cahuilla, the name used for any of the several prehistoric lakes to have occupied the Salton Sink, dried up some 300 years ago. In the past 2000 years, archaeological records indicate that the Colorado River actually headed northwest into the Salton Sink or Trough more often than it headed south into the Gulf of California.California Water Plan Update 2005

**Volume 3** Regional Reports 1211 Problems facing native fish in the mainstem Colorado River and its tributaries will not be easily resolved. For example, two fish species most in danger of extinction, the bonytail chub and razorback sucker, are not expected to survive in the wild. In recent years, most stream and reservoir fisheries in the basin have been managed for non-native fish. These managementpractices have harmed residual populations of native fish. Howe

ver the native fish species are readily propagated in hatcheries, such that recovery plans include captive broodstock programs to maintain the species.

R eestablishing wild populations from hatchery stocks will have to be managed in unison with programs that manage river habitat. For example, although 15 million juvenile razorback suckers were planted in Arizona streams from 1981through 1990, the majority of these planted fish were likely eaten by introduced predators. In 1994, the states of Colorado, Wyoming, and Utah reached an agreement with USFWS on protocols for stocking non-native fish in the Upper Basin. Stocking protocols are consistent with native fish recovery efforts. In a program which began in 1989, USBR and other federal and state agencies have cooperated to capture, rear, and successfully reintroduce about 15,000 razorback sucker larvae in Lake Mojave. Instream flows in the mainstem and key tributaries are being evaluated as components of native fish recovery efforts. State and federal agencies are conducting studies to estimate base flow and flushing flow needs for listed and sensitive species in various river reaches.

In the Lower Colorado River Basin, representatives of the three states, federal agencies, several Native American tribes, and Colorado River water and power users have completed and signed the Lower Colorado River Multi-Species Conservation Program (LCR MSCP). The LCR MSCP is intended to providelong-term compliance with the federal and California Endang ered Species Acts, as well as the fully protected species statutes in California.
The LCR MSCP is a 50-year program that is designed to provide more than 8,100 acres of high quality aquatic, wetland, and native broadleaf riparian habitat along the Lower Colorado River from Lake Mead to Mexico. The restored and maintained habitats are expected to provide ecological benefits and mitigate potential impacts to 26 covered species being addressed within the LCR MSCP. Some of the proposed habitat restoration may involve the conversion of existing agricultural lands to native riparian habitats, as well as removal of non-native salt cedar (tamarisk) and replacement with native broadleaf riparian habitat – cottonwood, willow, and mesquite, for example.


## Box 11-3 Salton Sea Ecosystem
The Salton Sea, a saline lake with a total dissolved solids of approximately 46,000 ppm (mg/L) - 33 percent greater than that of ocean water is California’s largest (surface area) lake and has been famous for its sport fishing and other recreational uses. It is also a federally designated repository to receive and store agricultural, surface, and subsurface drainage waters from the Imperial and Coachella valleys. The Salton Sea has a water surface elevation of about 229 feet below mean sea level.

Wildlife and aquatic species, which are dependent upon habitat created by the discharge of agricultural return flows, are threatened by the increasing salinity of the sea, as salts in the water are concentrated through evaporation. Thesea’s importance to wildlife has grown because about 95 percent of California’s wetlands in other areas have disappeared through changes in land use.

The Salton Sea ecosystem, including the Sonny Bono Salton Sea National Wildlife Refuge and adjacent agricultural lands, is considered a critical link on the International Pacific Flyway for migratory birds. The amount of freshwater inflow available to the Sea will be affected by water transfers to the South Çoast region as well as by water conservation in Mexico. As specified by the State Water Resources Control Board, IID is required to provide a defined freshwater inflow for mitigation from 2003 through 2017.
By the end of 2006, the California Resources Agency is required to complete a Salton Sea ecosystem restoration study and an environmental document to idenntify a preferred alternatiive for Salton Sea Restoration.1311 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

Additionally, the LCR MSCP participants plan to rear and reintroduce more than 660,000 razorback suckers and 620,000 bonytail to the mainstream of the Colorado River during the 50-year LCR MSCP. More than 360 acres of backwater habitats are to be created along the Lower Colorado River to provide nursery habitat for juvenile native fish and additional wetland habitat for marsh species and migratory waterfowl.
Several California water and power agencies that use Color ado River water were participants in the LCR MSCP planning process and are signatories to the plan. The LCR MSCP is expected to begin implementation in early 2005. The USBR, in conjunction with representatives of the three states and the U.S. Fish and Wildlife Service, will be the agency primarily responsible for implementing the LCR MSCP.
The Salton Sea, with its increasing salinity, selenium contamin ation, and eutrophication, is the primary focus of water quality issues within this hydrologic region. The largest sources of surface water inflow to the sea are the New and Alamo riversand the Imperial Valley agriculture drains, all of which contribu te pesticides, nutrients, selenium, and silt. The New River has been described as the most polluted river in the United States. Originating in Mexicali, Mexico, the New River flows across the border, through the city of Calexico, and then north, and empties into the Salton Sea. It conveys urban runoff, untreated and partially treated municipal and industrial wastes from the Mexicali Valley, and agricultural runoff from the Mexicaliand Imperial valleys. These pollution sources contribute pesticides, pathogens, silt, nutrients, trash, and volatile organic compounds (the latter, primarily from Mexican industry) to the sea. The Alamo River, which originates just two miles south of the border and also flows north to the Salton Sea, consists mainly of agricultural drainage from the Imperial Valley. The Coachella Valley Stormwater Channel, which also drains to the sea, at its north end is heavily contaminated with pathogens from municipal wastewater plants in the Coachella Valley and agricultural drainage.

A multiagency group, The Citizen’s Congressional Task Force on the New River, was created in 1997. Its mission is to improve agricultural drain water quality that flows intothe New River and, ultimately, to the Salton Sea. Participating agencies include IID, Desert Wildlife Unlimited, County of Imperial, USBR, U.S. Geological Survey, USFS, DFG, California Regional Water Quality Control Board, USEPA, Ducks Unlimited, and U.C. Riverside. In 2000, the Task Force constructed two pilot wetland projects, a seven-acre site nearBrawley and a 68-acre site near Imperial, to test the effectiven ess of constructed wetlands in lowering non-point source poll utants. Due to the success of the pilot sites, up to 30 additional wetland sites are proposed on both the New and Alamo rivers. Additional information on this program can be found on the Task Force web site at www.newriverwetlands.com.
Contamination in the Salton Sea presents threats to migrating birds on the Pacific Flyway. At certain times of the year, nutrient loading to the sea supports large algal blooms that contribute to odors, as well as low dissolved oxygen levels which adversely affect fisheries. Selenium is a more recent constituent of concern,and has the potential to adversely affect fish and wildlife.
The relatively saline Colorado River provides irrigation anddomestic water to much of Southern California. Of recent conc ern to human health is the presence of low levels of perchlorate in the Colorado River from a Kerr-McGee chemical facility in the Las Vegas Wash, the nation’s largest perchlorate contamination site. In addition high levels of hexavalent chromium occur in groundwater wells near the town of Needles, resulting from aPG&E natural gas compressing station. Septic systems at recrea tional areas along the river are also a concern for domestic and recreational water uses. Other important water quality issues in this region include increasing levels of salinity, nitrates and other substances in groundwater associated with animal feeding and dairy operations and septic tank systems, especially in the Desert Hot Springs area and in the Cathedral City Cove area. In the Coachella Valley, high levels of nitrates restrict the use of several domestic water supply wells.

T o address the issue of declining groundwater levels, CVWD prepared a water management plan for the lower Coachella Valley. The plan considered alternatives that include basin adjudication, water conservation, water recycling and direct or in lieu recharge with water imported from the Colorado River or from the SWP. This plan was completed and approved in 2002.

As a result of a 1964 U.S. Supreme Court decree in Arizona v. California, California’s basic apportionment of Colorado River water was quantified and five lower Colorado River Indian tribes were awarded 905,000 acre-feet of annual diversions, 131,400acre-feet of which were allocated for diversion in and chargeable to California pursuant to a later supplemental decree. In 1978, the tribes asked the court to grant them additional water rights, alleging that the U.S. failed to claim a sufficient amount of irrigable acreage, called omitted lands, in the earlier litigation. The tribes also raised claims called boundary land claims forCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 1411 more water based on allegedly larger reservation boundaries than had been assumed by the court in its initial award. In 1982, a Special Master appointed by the Supreme Court to hear these claims recommended that additional water rights be granted to the tribes. In 1983, however, the U.S. Supreme Court rejected the claims for omitted lands from further consideration and ruled that the claims for boundary lands could not be resolved until disputed boundaries were finally determined.
Three of the five tribes – the Fort Mojave Indian Tribe, the Fort Yuma-Quechan Indian Tribe, and the Colorado River Indian Tribe – are pursuing additional water rights related to the boundary lands claims. A settlement has been reached on the claims of the Fort Mojave Indian Tribe and the Colorado River Indian Tribe. The settlements as approved by the U.S. Supreme Court provide 5,122 acre-feet of additional diversions to these two tribes. An agreement has also been reached to settle the claim of the Fort Yuma - Quechan Indian Tribe, which is currently before the U.S. Supreme Court.
In 2003 legislation was enacted to enable the QSA’s local agency signatories to reach agreement on how to reduce their use of Colorado River water to California’s basic interstate apportionment of 4.4 million acre-feet annually. As a result of this legislation the State accepted significant responsibilities and liabilities for mitigation of QSA environmental impacts and for restoration of the Salton Sea ecosystem, The QSA implementa

tion legislation is contained in three approved bills, SB 277 (Ducheny), SB 317 (Kuehl), and SB 654 (Machado), which were chaptered in 2003. Among other things, the legislation establishes State policy with respect to Salton Sea, stating theintent of the Legislature that the State would undertake the restoration of Salton Sea ecosystem and permanent protection of its fish and wildlife. It provides that no further funding obligations or in-kind contributions for Salton Sea restoration would be required of IID, CVWD, MWD, or SDCWA. Any future actions to restore Salton Sea would be the sole responsibility of the State. Additionally, IID is held harmless from Salton Sea impacts resulting from transfers of conserved water.
With respect to QSA implementation, the legislation authorizes DFG to issue incidental take permits for California’s fully protected species, and provides that DFG chair a joint powers authority whose other members are SDCWA, IID, and CVWD. The three local agencies are to contribute $133 million to the joint powers authority for QSA environmental mitigation, with the State being responsible for mitigation in excess of that amount. The three local agencies are also to contribute $30 million to the Salton Sea Restoration Fund managed by DFG. The legislation provides for a conditional transfer of conservedwater from IID to MWD of up to 1.6 million acre-feet of Color ado River water, under specified terms. Proceeds from sale of the water – estimated at up to $300 million – are to go to the Salton Sea Restoration Fund. The Secretary for Resources is directed to prepare a Salton Sea ecosystem restoration study and environmental documentation, and identify a preferred alternative by the end of 2006. The study, to be conducted in consultation with a legislatively mandated advisory committee and with the Salton Sea Authority, is to include a proposed funding plan for implementing the preferred alternative. 

### AccomplishmentsOver the past 20 years, several large-scale water conserv ation actions involving Colorado River water users have been completed, as shown in Table 11-7. Since 1993, development and implementation of these programs andprojects have included consideration of environmental issues and environmental justice values.


## Relationship with Other RegionsAfter eight years of negotiations, the signing of the Quantificat ion Settlement Agreement on October 10, 2003, facilitated a second long-term water transfer from the Imperial Irrigation District in the Colorado River Hydrologic Region to urban water users in the South Coast Hydrologic Region. It will also make possible the transfer of additional water to be obtained through lining of the All American and the Coachella canals. The water transfer from IID will help stabilize MWD’s, SDCWA’s and CVWD’s water supplies, satisfy outstanding miscellaneous and Indian water rights, and provide funding that IID and farmers in the Imperial Valley will use for addi

tional water conservation measures once the required interim fallowing period is completed.
Although the facilities to deliver SWP water supplies to the region have yet to be built, CVWD and DWA receive theirannual allocations of SWP water through an exchange agreement with the South Coast region’s largest water wholesale agency, MWD. These districts are also participants in another agreement that delivers and stores water from the Colorado River into the Coachella Valley’s largest groundwater basin during periods of high flows.
Water districts in both regions are also cooperating in water conservation and land fallowing programs. The 1988 IID/ MWD Water Conservation Agreement resulted in conservation1511 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

Year Action Participants Comments/Status Estimated Savings 1980 Line 49 miles USBR, CVWD, Project completed. 132 taf/yr of Coachella Canal 1990 IID distribution IID, MWD Project completed. Under QSA agreement Conservation verification in 1998 - system extends through 2037 (2047, if not 107 taf improvement terminated by SDCWA; 2077, if renewed and on-farm by mutual consent of IID / SDCWA) water Conservation projects - canal lining, management regulatory reservoirs, lateral spill projects interceptor canals, tailwater return designed to systems, non-leak gates, 12-hour water conserve 100 delivery, drip irrigation, and system taf/yr. automation. MWD funded $96.5 million (1988$) for program costs; pays O&M for duration of agreement. 1992 Groundwater MWD, Central T est program to bank up to 300 taf. MWD and SNWA have stored 139 banking in Arizona WCD, taf in Arizona groundwater basins. Arizona So. Nevada WA 1992 PVID land PVID, MWD Project completed. Two-year land fallowing 186 taf were made available, but fallowing test program. Covered 20,215 acres in the water was subsequently spilled PVID.MWD paid $25 million to farmers from Lake Mead when flood control over a two-year period. releases were made from the reservoir. 1995 Partnership USBR, CVWD Provides, among other things, for studies N/A agreement to optimize reasonable beneficial use of water in the district. 2003 Water transfer IID, SDCWA, Initial term of 35 years; 45 years if not ter- In 2003, SDCWA receives 10 taf and agreement CVWD minated by SDCWA; 75 years if renewed the Salton Sea receives 5 taf. By 2017, by mutual consent of IID / SDCWA. SDCWA amount increases to100 taf SDCWA pays for water transferred & and the Salton Sea amount increases to Sea. to 150 taf. From 2018 through the remainder of agreement (2077, if extended), SDCWA would receive 200 taf (from 2001 on) and the Salton Sea would receive 0 acre-feet. For CVWD, it receives 4 taf in 2008 and 103 taf by 2024. This decreases to 100 taf in 2039, if agreement is extended. 2003 Land lease PVID, PVID conser ved and transferred water 40.6 taf in 2003. agreement CVWD supplies to CVWD. 2003 Canal Lining IID, CVWD, Portions of the All American Canal and 67.7 taf/yr - All American Canal San Luis Rey the Coachella Canal will be lined. 26 taf/yr - Coachella Canal River Indian SDCWA pays for construction and O&M. Water Authority, 16 taf will be provided for the San Luis other Indian Rey Indian water rights settlement. tribes **Table 11-7 Existing Colorado River Region Water Conservation Actions / Agreements Since 1980** California Water Plan Update 2005

**Volume 3** Regional Reports 1611 

## Box 11-4 Key Elements of California’s Colorado River Quantification Settlement Agreement
The California Colorado River Quantification Settlement Agreement and related agreements will have the following ef fects:

• Permit the utilization of interim surplus water.

• Transfer as much as 30 million acre-feet of water from farms to cities in Southern California for up to the 75 year term of the agreement.

• Settle potential lawsuits between the Imperial Irrigation District and the U.S. Department of the Interior.

• Obligate California with the sole responsibility for restoration of the Salton Sea ecosystem.

• Provide for cooperation on the environmental review and mitigation for the Imperial Irrigation District/ San Diego County Water Authority Transfer Agreement, IID/ Coachella Valley Water District Acquisition Agreement, and Salton Sea habitat conservation plan/natural community conservation plan.

• Fund a $200 million project to line with concrete a portion of the earthen All-American Canal and a portion of the earthen Coachella Canal. Water conserved by reducing seepage will be transferred to San Diego and the San Luis Rey Indian Tribes, who will pay proportionally for operation and maintenance costs.

• Quantify, for the first time, the total Colorado River apportionments in California. of water supplies from the construction of new facilities, water

s ystem automation, and the implementation of technical assistance programs for farmers within the IID water service area. The conserved water is delivered to MWD and CVWD.
As part of an on-going agreement, MWD will provide technical and financial assistance to the PVID for theconstruction of facilities and implementation of prog rams to conserve water supplies within the PVID service area. MWD will be permitted to divert conserved water supplies resulting from these projects and programs.


## Looking to the Future On October 10, 2003, MWD, IID, CVWD, SDCWA, and the Secretary of the Interior signed the Colorado River WaterDelivery Agreement: Federal Quantification Settlement Agreement (QSA) for the purpose of Section 5(B) of the Interim Surplus Guidelines. This agreement specifies, how, over time, California will reduce its use of Colorado River water to its basic apportionment of 4.4 million acre-feet per year in all years, except for those years in which the Secretary of the Interior declares a surplus of water on the Colorado River.
The QSA will remain in effect for 35 years, or 45 years if not terminated by SDCWA, or 75 years if renewed by mutual consent of IID and SDCWA. The QSA is expected to achieve the objective sought by the other Colorado River Basin states and the federal government of reducing California’s use of Colorado River water to its annual basic apportionment of 4.4 million acre-feet. This reduction will be achieved through, among other practices, transfer of water use from IID to SDCWA and to CVWD. While it is the intent of IID to transfer water saved through conservation, from 2003 through 2012 all of the water transferred to SDCWA will come from land fallowing. Fallowing for this transfer will decrease from a high of 90,000 acre-feet per year in 2012, until by 2017 all water transferred to SDCWA will come from efficiency conservation measures. At the same time, additional land fallowing will occur to meet flow requirements (5,000 acre-feet per year in 2003, growing to 150,000 acre-feet in 2017 unless reduced or eliminated as a result of “Salton Sea Restoration”) for envi

ronmental mitigation as a result of the reduced agricultural drainage to the Salton Sea.

At its peak, land fallowing in the IID service area is anticipated to be up to 40,000 acres, as needed to provide up to 150,000 acre-feet of mitigation water to the Salton Sea in 2017. After 15 years, it is expected that improvements in water use efficiency will be sufficient to meet the terms of the QSA, and land fallowing would no longer be needed for environmental mitigation. One of the long-term assumptions in MWD’s Integrated Resources Plan is that MWD’s Colorado River supply will be maximized through water transfers from agricultural water users in the Colorado River hydrologic region (IID and PVID) to urban water users in the South Coast hydrologic region (SDCWA and MWD).1711 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

The agricultural water purveyors in the region (IID, PVID, CVWD, and Bard Water District) will continue to implement Efficient Water Management Practices. Water districts in the Coachella Valley will continue with their efforts to provide technical assistance to the managers of large landscape areas to help improve the efficiencies of irrigation.
CVWD and DWA will continue to work together to addressdeclining water levels in the Coachella Valley’s largest groundw ater basin, the Indio sub-basin. CVWD is operating an active groundwater recharge program for the upper end of the Coachella Valley, generally, the urbanized part of the valley. CVWD recharges groundwater with imported Colorado River water and with Whitewater River flows using percolation ponds. CVWD and DWA levy extraction fees on larger groundwater users in the upper Coachella Valley.
With support from the Quechan Indian Reservation and fromthe Southern Low Desert Resource Conservation and Development Council, Bard Water District (BWD) is undertaking an$8 million project for capital improvements on the Reservation Division of the USBR’s Yuma Project. This improvement project is mostly funded by a $4 million matching grant from the North American Development Bank. The Quechan Indian Reservation contributed $2 million of the matching funds and$2 million was raised by BWD customers. BWD is rehabilitating about 10 miles of earthen canals with concrete lining and pipeline in 2004 and an additional 10 miles are to be rehabilitated in 2005. BWD will also be replacing more than 100 irrigation gates and structures. These improvements will greatly increase the effectiveness of its system by reducing canal seepage and evaporation.
Over the years, the USBR and others have considered potential solutions to stabilize the Salton Sea’s salinity and elevation. Most recently, the Salton Sea Authority has been performing appraisal level evaluations of some of the frequently suggested alternatives, such as large scale pump-in, pump-out pipelines to the Pacific Ocean. The authority is investigating integrated strategies where a smaller, lower salinity lake with a stable water surface would be coupled with treatment/desalination of some brackish inflows. The treated water could then be sold or could be part of a water transfer that would help fund the project.
Under direction contained in the QSA implementing legislation,the Secretary of the California Resources Agency is undertaking a study of alternatives for restoration of the Salton Sea. A deadline of December 31, 2006 was established for the completion of the study and submittal to the legislature. T he Colorado River Quantification Settlement Agreem ent (QSA), finalized and signed in October 2003, outlines key elements for California to operate within its basic annual allotment of 4.4 million acre-feet from the Colorado River, as summarized in Box 11-4.



## Water Portfolios for Water Years **1998, 2000, and 2001** Above average rainfall occurred during water year 1998 in Blythe, with near average rainfall elsewhere in the region. For water years 2000 and 2001, rainfall totals were below average; and 2000 could also be considered as a dry year. In water year 1998, rainfall totals were 176 percent above average for the National Weather Service station in Blythe, 104 percent of average for the El Centro 2 SSW station and 108 percent of average for Palm Springs.

W

ater year 2000 was very dry. Rainfall totals measured by the Blythe station for the year were only 17 percent of average; for El Centro, 10 percent of normal; and for Palm Springs, 35 percent of normal. Conditions improved slightly for water year 2001. The Blythe station measured rainfall that was 120 percent of normal. For El Centro, it was 78 percent of normal. For Palm Springs, it was 74 percent.

T ables 11-8 through 11-10 present actual information about the water supplies and uses for the Colorado River hydrologic region for these three years. About 85 percent of the region’s water comes from surface deliveries from the Colorado River. The high level of agricultural activity in the region is reflected by the large agricultural water demand relative to other water uses. In 2000, agricultural water demand was 85 percent of all developed applied water uses in the region. By contrast, urban water use only accounted for 14 percent of total demand. The Water Portfolio Flow Diagrams (Figures 11- 4 and 11-5) provide a graphical presentation of how water supplies are distributed and used throughout this region.

D espite the climatological conditions, demands for water supplies by the region’s urban and agricultural users and the environment did not exhibit any large fluctuations during the years between 1998 and 2001. The total applied water demand for 1998 was 4,602,000 acre-feet. For 2000, the demand increased slightly to 4,726,900 acre-feet. In 2001, it decreased to 4,536,800 acre-feet.California Water Plan Update 2005

**Volume 3** Regional Reports 1811 **Water Entering the Region** Precipitation 9,455 3,034 4,770 Inflow from Mexico 182 166 155 Inflow from Colorado River 4,986 5,349 5,197 Imports from Other Regions 0 0 0 **Total 14,623 8,549 10,122**  **Water Leaving the Region** Consumptive Use of Applied Water * 2,814 2,865 2,775 (Ag, M&I, Wetlands) Outflow to Oregon/Nevada/Mexico 0 0 0 Expor ts to Other Regions 1,081 1,296 1,250 Statutory Required Outflow to Salt Sink 0 0 0 Additional Outflow to Salt Sink 1,185 1,252 1,228 Evaporation, Evapotranspiration of Native V egetation, Groundwater Subsurface Outflows, 9,646 3,320 5,049 Natural and Incidental Runoff, Ag Effective Precipitation & Other Outflows **Total 14,726 8,733 10,302**  **Storage Changes in the Region** [+] Water added to storage [-] Water removed from storage Change in Surface Reservoir Storage -15 -19 1 Change in Groundwater Storage ** -88 -165 -181 **Total -103 -184 -180**  **Applied Water *** (compare with Consumptive Use) 4,107 4,288 4,174

*Footnote for applied water Consumptive use is the amount of applied water used and no lon ger available as a source of supply. Applied water is greater than consumptive use because it includes consumptive use, reuse, and outflows.

**Footnote for change in Groundwater Storage

C hange in Groundwater Storage is based upon best available information. Basins in the north part of the state (North Coast, San Francisco, Sacramento River and North Lahontan regions and parts of Central Coast and San Joaquin River regions) have been modeled – spring 1997 to spring 1998 for the 1998 water year and spring 1999 to spring 2000 for the 2000 water year. All other regions and year 2001 were calculated using the following equation:
GW change in storage = intentional recharge + deep percolation of applied water + conveyance deep percolation - withdrawals
This equation does not include the unknown factors such as natu ral recharge and subsurface inflow and outflow. Water Year (Percent of Normal Precipitation) 1998 (154%) 2000 (50%) 2001 (80%) **Table 11-8 Colorado River Hydrologic Region Water Balance Summary - TAF**  Water Entering the Region – Water Leaving the Region = Storage Changes in Region1911 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

Applied Net Depletion Applied Net Depletion Applied Net Depletion Water Use Water Use Water Use Water Use Water Use Water Use 2001 1998 2000

**WATER USE Table 11-9**  **Colorado River Region Water Use and Distribution of Dedicated Supplies (TAF)**

**DEDICATED WATER SUPPLIES Urban**  Large Landscape 156.9 148.8 122.4 Commercial 71.4 123.5 145.0 Industrial 3.3 4.6 4.6 Energy Production 76.7 76.7 76.7 Residential - Interior 170.0 170.3 159.1 Residential - Exterior 65.2 59.1 75.1 Evapotranspiration of Applied Water 222.1 222.1 207.9 207.9 196.5 196.5 E&ET and Deep Perc to Salt Sink 76.6 76.6 82.8 82.8 84.6 84.6 Outflow 124.7 124.7 129.9 129.9 131.0 131.0 Conveyance Applied Water 0.0 0.0 0.0 Conveyance Evaporation & ETAW 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Outflow 0.0 0.0 0.0 0.0 0.0 0.0 GW Recharge Applied Water 156.4 100.6 24.1 GW Recharge Evap + Evapotranspiration 0.0 0.0 0.0 0.0 0.0 0.0 **Total Urban Use 700.0 423.4 423.4 683.5 420.6 420.6 606.9 412.1 412.1**  **Agriculture** On-Farm Applied Water 3,531.8 3,674.6 3,561.7 Evapotranspiration of Applied Water 2,560.4 2,560.4 2,627.3 2,627.3 2,548.5 2,548.5 E&ET and Deep Perc to Salt Sink 80.3 80.3 86.8 86.8 83.5 83.5 Outflow 723.3 723.3 778.9 778.9 752.1 752.1 Conveyance Applied Water 338.6 338.6 338.6 Conveyance Evaporation & ETAW 64.0 64.0 64.0 64.0 64.0 64.0 Conveyance Deep Perc to Salt Sink 167.6 167.6 167.6 167.6 167.6 167.6 Conveyance Outflow 107.0 107.0 107.0 107.0 107.0 107.0 GW Recharge Applied Water 0.0 0.0 0.0 GW Recharge Evap + Evapotranspiration 0.0 0.0 0.0 0.0 0.0 0.0 **Total Agricultural Use 3,870.4 3,702.6 3,702.6 4,013.2 3,831.6 3,831.6 3,900.3 3,722.7 3,722.7**  **Environmental** Instream Applied Water 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Wild & Scenic Applied Water 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Required Delta Outflow Applied Water 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Managed Wetlands Habitat Applied Water 31.6 30.2 29.6 Evapotranspiration of Applied Water 31.6 31.6 30.2 30.2 29.6 29.6 E&ET and Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Applied Water 0.0 0.0 0.0 Conveyance Evaporation & ETAW 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Total Managed Wetlands Use 31.6 31.6 31.6 30.2 30.2 30.2 29.6 29.6 29.6 **Total Environmental Use 31.6 31.6 31.6 30.2 30.2 30.2 29.6 29.6 29.6**  **TOTAL USE AND OUTFLOW 4,602.0 4,157.6 4,157.6 4,726.9 4,282.4 4,282.4 4,536.8 4,164.3 4,164.3**

**Surface Water** Local Deliveries 6.6 6.6 6.6 6.3 6.3 6.3 4.0 4.0 4.0 Local Imported Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Colorado River Deliveries 3,905.1 3,905.1 3,905.1 4,053.0 4,053.0 4,053.0 3,946.6 3,946.6 3,946.6 CVP Base and Project Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Other Federal Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 SWP Deliveries 156.4 156.4 156.4 100.6 100.6 100.6 24.1 24.1 24.1 Required Environmental Instream Flow 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Groundwater Net Withdrawal 73.4 73.4 73.4 105.3 105.3 105.3 171.7 171.7 171.7 Deep Percolation of Surface and GW 313.6 311.0 237.1 Reuse/Recycle Reuse Surface Water 130.8 133.5 135.3 Recycled Water 16.1 16.1 16.1 17.2 17.2 17.2 17.9 17.9 17.9 **TOTAL SUPPLIES 4,602.0 4,157.6 4,157.6 4,726.9 4,282.4 4,282.4 4,536.7 4,164.3 4,164.3**  **Balance = Use - Supplies 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0** California Water Plan Update 2005

**Volume 3** Regional Reports 2011 Minor reductions in the irrigated crop acres occurred from 1998 to 2000, followed by a slight increase for 2001. Total crop acreage for the region (including double-cropping) was 761,760 acres in 1998, 731,890 acres for 2000, and 739,830 for 2001. Noticeable declines were observed for irrigated grains and other field crop categories. A steady increase in production acreage has been observed for the vegetables crops classified in the “other truck” category.



## Selected References 2002 California 305(b) Report on Water Quality, State Water Resources Control Board. Agency for Toxic Substances and Disease Registry. “Toxicological Profile for Chromium”. May 25, 2001. www.atsdr.cdc.gov/toxprofiles/tp7.html A ssociated Press. “Key elements of Colorado River water deal.” October 17, 2003. Califor nia Environmental Protection Agency (EPA) website. www.calepa.ca.gov/ o List of Drinking W ater Contaminants and MCLs. o Drinking Water Contaminant Candidate List. o Regulations and Guidance. Califor nia’s Groundwater Bulletin 118 (Draft), Update 2003, California Department of Water Resources. www.ground water.water.ca.gov/bulletin118/index.cfm C hemical & Engineering News, “Rocket-Fueled River<” August 18, 2003. www.pubs.acs.org/cen/coverstory/ 8133/8133perchlorates.html Coachella V alley Water District. www.cvwd.org/ Colorado River Basin Regional Water Quality Control Board. www.waterboards.ca.gov/coloradoriver/ Colorado River Board of Califor nia. www.crb.ca.gov/ Colorado River Water Delivery Agreement: Federal Quantification Settlement Agreement for Purposes of Section 5(B)of Interim Surplus Guidelines. October 10, 2003. www.saltonsea.water.ca.gov/crqsa/index.cfm [DHS] California Department of Health Services, “Drinking Water Standards”. www.dhs.ca.gov/ps/ddwem/publica tions/Regulations/regulations_index.htm D HS. “Chemical Contaminants in Drinking Water”. July 3, 2003. www.dhs.ca.gov/ps/ddwem/chemicals/chemindex.htm DHS. “Drinking Water Action Level, Chemicals with Recent Detections”. June 12, 2003. DHS. “Drinking Water Action Levels, Historic Action Levels and Action Levels for Contaminants Detected Infrequently”. June 30, 2003. DHS. “Specific Contaminants of Current Interest: arsenic, chromium-6, manganese, methyl tertiary butyl ether (MTBE), N-nitrosodimethylamine (NDMA), perchlorate, 1, 2, 3-trichloropropane. D HS. “Perchlorate in California Drinking Water: Status of Regulations and Monitoring”. July 2, 2003. D HS. “Chromium-6 in Drinking Water: Background Information”. April 8, 2003. D HS. “Chromium-6 in Drinking Water: Regulation and Monitoring Update”. July 16, 2003. G roundwater Resources Association of California. “Perchlorate and NDMA: Rocket Fuel Contaminants a Serious Challenge to Drinking Water Suppliers”. News release. April 4, 2002. www.grac.org/pernewsrelease.html Imperial Irrigation District. www.iid.com/water/ Lower Colorado River Multi-Species Conservation Program Web site. www.lcrmscp.org Metropolitan W ater District of Southern California. www.mwdh2o.com/ N onpoint Source Program Strategy and Implementation Plan, 1998-2013, State Water Resources Control Board, California Coastal Commission, January 2000. www.coastal.ca.gov/nps/npsndx.html Palo Verde Irrigation District. www.citlink.net/~davegun/pvid.html “Presentation by staff of the State Water Resources Control Board and staff of the Department of Toxic Substances Control”. 2003. Salton Sea Authority

. www.saltonsea.ca.gov/ State Water Resources Control Board. “Perchlorate Contamination of California’s Groundwater Supplies”. www.swrcb. ca.gov/rwqcb4/html/perchlorate.html S trategic Plan, State Water Resources Control Board, Regional Water Quality Control Boards, November 15, 2001. www.waterboards.ca.gov/strategicplan/index.html US Bureau of Reclamation. www.usbr.gov/ US Fish and Wildlife Ser vice. www.fws.gov/ US Geological Survey National Water Quality Assessment Program. www.water.usgs.gov/nawqa/ US Geological Sur vey online publications. www.pubs.usgs.gov/products/ U S EPA. Ground Water & Drinking Water website. “Perchlorate”. January 23, 2003. www.epa.gov/safewater/ US EPA. “Perchlorate Environmental Contamination: Toxicological Review and Risk Characterization (External Review Draft)”. 2002. www.cfpub.epa.gov/ncea/cfm/recordis play.cfm?deid=240022111 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005

Water Quality Control Plan, Regional Water Quality Control Board. www.swrcb.ca.gov/rwqcb3 W ater Quality Control Plan, Regional Water Quality Control

Board. www.swrcb.ca.gov/rwqcb3 W atershed Management Initiative Chapter, Regional Water

Quality Control Board. www.waterboards.ca.gov/lahon tan/WMI/WMI_Index.htm W

estern Regional Climate Center website. www.wrcc.dri.edu/2311 **Chapter 11** Colorado River Hydrologic Region California Water Plan Update 2005



# Water Portfolios

Colorado River Hydrologic RegionCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 2411 **Table 11-10 Colorado River region water portfolio (TAF)** 

ID Colorado River Colorado River Colorado River Number: Flow Diagram Component (see legend) 1998 2000 2001 1 Colorado River Deliveries 3,905.1 4,053.0 3,946.6 2 Total Desalination

- - - 3 Water from Refineries

- - - 4a Inflow From Oregon

- - - b Inflow From Mexico 182.4 165.6 154.7 5 Precipitation 9,454.8 3,033.9 4,769.9 6a Runoff - Natural N/A N/A N/A b Runoff - Incidental N/A N/A N/A 7 Total Groundwater Natural Recharge N/A N/A N/A 8 Groundwater Subsurface Inflow N/A 9 Local Deliveries 6.6 6.3 4.0 10 Local Imports

- - - 11a Central Valley Project :: Base Deliveries

- - - b Central Valley Project :: Project Deliveries

- - - 12 Other Federal Deliveries

- - - 13 State Water Project Deliveries 156.4 100.6 24.1 14a Water Transfers - Regional

- - - b Water Transfers - Imported

- - - 15a Releases for Delta Outflow - CVP b Releases for Delta Outflow - SWP c Instream Flow Applied Water

- - - 16 Environmental Water Account Releases

- - - 17a Conveyance Return Flows to Developed Supply - Urban

- - - b Conveyance Return Flows to Developed Supply - Ag

- - - c Conveyance Return Flows to Developed Supply - Managed Wetlands

- - - 18a Conveyance Seepage - Urban

- - - b Conveyance Seepage - Ag

- - - c Conveyance Seepage - Managed Wetlands

- - - 19a Recycled Water - Agriculture

- - - b Recycled Water - Urban 16.1 17.2 17.9 c Recycled Water - Groundwater

- - - 20a Return Flow to Developed Supply - Ag

- - - b Return Flow to Developed Supply - Wetlands

- - - c Return Flow to Developed Supply - Urban

- - - 21a Deep Percolation of Applied Water - Ag 47.8 48.8 44.6 b Deep Percolation of Applied Water - Wetlands

- - - c Deep Percolation of Applied Water - Urban 109.4 161.6 168.4 22a Reuse of Return Flows within Region - Ag 130.8 133.5 135.3 b Reuse of Return Flows within Region - Wetlands, Instream, W&S

- - - 24a Return Flow for Delta Outflow - Ag

- - - b Return Flow for Delta Outflow - Wetlands, Instream, W&S

- - - c Return Flow for Delta Outflow - Urban Wastewater

- - - 25 Direct Diversions N/A N/A 26 Surface Water in Storage - Beg of Yr 580.8 585.4 566.9 27 Groundwater Extractions - Banked

- - - 28 Groundwater Extractions - Adjudicated

- - - 29 Groundwater Extractions - Unadjudicated 387.0 416.3 408.8 23 Groundwater Subsurface Outflow N/A N/A N/A 30 Surface Water Storage - End of Yr 566.3 566.9 568.3 31 Groundwater Recharge-Contract Banking -14.7 -59.2 -8.9 32 Groundwater Recharge-Adjudicated Basins

- - - 33 Groundwater Recharge-Unadjudicated Basins

- - - 34a Evaporation and Evapotranspiration from Native Vegetation N/A N/A b Evaporation and Evapotranspiration from Unirrigated Ag N/A N/A 35a Evaporation from Lakes 1555.5 1552.5 1552.4 b Evaporation from Reservoirs 120 121.5 120.6 36 Ag Effective Precipitation on Irrigated Lands 146.6 14.1 76.2 37 Agricultural Water Use 3,531.8 3,674.6 3,561.7 38 Managed Wetlands Water Use 31.6 30.2 29.6 39a Urban Residential Use - Single Family - Interior 144.2 154.6 123.1 b Urban Residential Use - Single Family - Exterior 57.1 55.8 67.4 c Urban Residential Use - Multi-family - Interior 25.9 15.7 36.0 d Urban Residential Use - Multi-family - Exterior 8.1 3.3 7.7 40 Urban Commercial Use 71.4 123.5 145.0 41 Urban Industrial Use 3.3 4.6 4.6 42 Urban Large Landscape 156.9 148.8 122.4 43 Urban Energy Production 76.7 76.7 76.7 44 Instream Flow

- - - 45 Required Delta Outflow

- - - 46 Wild and Scenic Rivers

- - - 47a Evapotranspiration of Applied Water - Ag 2560.4 2627.3 2548.45 b Evapotranspiration of Applied Water - Managed Wetlands 31.6 30.2 29.6 c Evapotranspiration of Applied Water - Urban 222.102 207.9 196.48 48 Evaporation and Evapotranspiration from Urban Wastewater

- - - 49 Return Flows Evaporation and Evapotranspiration - Ag 80.3 86.8 83.5 50 Urban Waste Water Produced 61.9 67.6 69.2 51a Conveyance Evaporation and Evapotranspiration - Urban 13.91 14.42 14.6 b Conveyance Evaporation and Evapotranspiration - Ag 64 64 64 c Conveyance Evaporation and Evapotranspiration - Managed Wetlands

- - - d Conveyance Outflow to Mexico N/A N/A 52a Return Flows to Salt Sink - Ag 997.9 1053.5 1026.7 b Return Flows to Salt Sink - Urban 187.39 198.28 201 c Return Flows to Salt Sink - Wetlands

- - - 53 Remaining Natural Runoff - Flows to Salt Sink

- - - 54a Outflow to Nevada

- - - b Outflow to Oregon

- - - c Outflow to Mexico

- - - 55 Regional Imports 4,986.0 5,349.0 5,197.0 56 Regional Exports 1081 1296 1250 59 Groundwater Net Change in Storage -88.1 -164.5 -180.6 60 Surface Water Net Change in Storage -14.5 -18.5 1.4 61 Surface Water Total Available Storage 620.4 620.4 620.4
Inflows Outflows Green number signifies included in summary boxes**Chapter 11** Colorado River Region 2 5 11 **Volume 3**  Regional Reports California Wa ter Plan Update 200 52 6 11 **Volume 3**  Regional Reports **Chapter 11** Colorado River Region California Wa ter Plan Update 200 5

## Chapter 12 Sacramento-San Joaquin Delta Region 

# Volume 3i12 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005 

# Chapter 12 Sacramento-San Joaquin Delta Region

Contents Chapter 12 Sacramento-San Joaquin Delta Region ..................................................................................................12-1 Setting

............................. 12-1 Topography and Climate ...............................................................................................................................12-1 Land Use ..................... 12-2 Population ................... 12-2 Water Use ................... 12-2 Water Exported from the Delta ......................................................................................................................12-4 Water Standards .......... 12-5 CALFED Bay-Delta Program ...............................................................................................................................12-6 State of the Region ............ 12-7 Water Supply Reliability 12-9 Water Quality .............. 12-9 Salinity .................. 12-9 Mercury ................ 12-9 Dissolved Oxygen (DO) ........................................................................................................................12-10 Organic Carbon (TOC) .........................................................................................................................12-10 Selenium ............. 12-11 Pesticides ............. 12-11 Toxicity of Unknown Origin ...................................................................................................................12-12 Ecosystem Restoration . 12-12 Levee System Integrity . 12-13 Recreation .................. 12-13 Looking to the Future ....... 12-14 Water Supply Reliability ..............................................................................................................................12-15 Delta Improvements Package .................................................................................................................12-16 In-Delta Storage Project ........................................................................................................................12-15 Los Vaqueros Reservoir Expansion .........................................................................................................12-15 Water Quality ............ 12-16 Delta Improvements Package .................................................................................................................12-15 Delta Region Water Quality Management Plan .......................................................................................12-18 DWR MWQI Program ..........................................................................................................................12-18 CALFED Storage Projects ......................................................................................................................12-18 Ecosystem Restoration . 12-18 Delta Improvements Package .................................................................................................................12-18 Delta Region Farmland Preservation and Private Lands Stewardship Program ...........................................12-19 Other CALFED ERP Projects ...................................................................................................................12-19 Levee System Integrity . 12-19 Oversight ............. 12-19 Funding ............... 12-19 Ecosystem Integration ...........................................................................................................................12-20 Recreation .................. 12-20 Other Activities ........... 12-20 Selected References ......... 12-21Page intentionally blankiii12 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005



## Boxes Box 12-1 California Bay-Delta Authority .................................................................................................................12-7 Box 12-2 Organic Carbon ... 12-11 Box 12-3 Ongoing Planning Ef forts ......................................................................................................................12-14 Box 12-4 Franks T ract Description ........................................................................................................................12-17



## Figures Figure 12-1 Delta water balance for year 2000 ..................................................................................................... 12-iv Figure 12-2 Delta region population .......................................................................................................................12-3 Figure 12-3 CALFED objectives ..............................................................................................................................12-5 Figure 12-4 Proposed Delta gates map ...................................................................................................................12-8 Figure 12-5 Delta Improvements Program map ......................................................................................................12-10 Figure 12-6 In-Delta Storage Project (map) ...........................................................................................................12-16



## Tables Table 12-1 Crop acreage and applied water demand in the Delta service area as of 2000 .........................................12-4 T able 12-2 Water balance for the Delta region ........................................................................................................12-6**Volume 3** Regional Reports California Water Plan Update 2005

**Figure12-1 Delta water balance for year 2000**

Water entering the Delta Water leaving the Delta Delta Boundary - Section 12220 of the Water Code Delta Service Area - The area that is irrigated from nearby Delta channels Delta Uplands - Those lands above the five-foot contour which area served from the Lowland Delta channels Delta Lowlands - Those lands approximately at the five-foot countour and below

0 2 4

Sc ale 6 Miles Delta Water Balance Average Water Year 2000 N O RT

H B

A Y A

Q U E D U CT 50

580 205 5 5 80 80

4

4

120 99 99

12

12 12 1 13 220

160 160 84

RIVER SACRAMENTO

SAN JOAQUIN

RIVER LODI SACRAMENTO

RIO VISTA

UPLANDS UPLANDS DELTA SERVICE AREA

DELTA BOUNDARY

LOWLANDS Yolo Bypass 2,956 TAF

North Bay Aqueduct (SWP) 47 TAF

Outflow 18,144 TAF

Contra Costa Water District 126 TAF Consumptive Use 1,690 TAF Precipitation

954 TAF Sacramento River 18,327 TAF

Eastside Tributaries 1,076 TAF

San Joaquin River 2,841 TAF Central Valley Project 2,482 TAF Banks Pumping Plant (SWP) 3,666 TAF Tracy Pumping Plant Banks Pumping

Plant

Delta water balance for water year 2000 includes key annual Del ta inflows, exports, precipitation, consumptive use, and Net Delta Outflow.112 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005



# Chapter 12 Sacramento-San Joaquin Delta Region

The region’s resources must be managed for generations to come. The overarching challenge involves finding ways for all the interests who benefit from the Delta to integrate a vast array of projects intended to improve water quality, ecosystem health, levee stability, and water supply in ways that provide long-term, sustainable benefits at reasonable costs to everyone. This regional report for the Delta Region is an overview of recent efforts to carry out actions that will help the region to continue to serve society’s demand for farm products, fishing, recreation, and water—all while protecting the Delta’s ecosys

t em and water quality. The intent of the profile is to give readers a sense of the region’s water resource management prioritiesand outline major efforts to integrate water resource management activities in the Delta. For more detailed information about actions and projects mentioned in this profile, consult the selected references noted at the end of this chapter. 

### Topography and Climate The Delta is a unique and valuable resource and an integral part of California’s water system. Located at the confluence of the Sacramento and San Joaquin Rivers, the Delta is part of the largest estuary system on the West Coast and is the keystone to operation of the two largest water projects in California the SWP and the federal Central Valley Project (CVP). The region extends from the confluence of the two rivers inland to Sacramento and Stockton and spans roughly 750,000 acres. A large part of this land is below sea level, and relies on more than 1,100 miles of levees for protection against flooding along the hundreds of miles of interlaced waterways.
The Delta’s network of waterways conveys runoff toward San Francisco Bay and the Pacific Ocean from over 40 percent of California’s land area. Major tributaries include the Sacra

mento, San Joaquin, Calaveras, Cosumnes, and Mokelumne rivers. These rivers plus their tributaries carry 47 percent of the state’s total annual runoff. 

## Setting Until 1850, the Sacramento-San Joaquin Delta (Delta) was wild, a tidal marsh with islands and river channels that changed according to nature’s will. By the 1870s, settlers had built levees and turned marshland into farmland. Farming on a commercial scale became a way of life. The 1870s and 1880s saw the arrival of commercial fisheries that introduced nonnative species—striped bass and American shad. As decades passed, commerce grew, and ocean shipping began using Delta ports to transport goods between California and foreign markets. Along with international shipping came invasive aquatic species unintentionally carried to the Delta in the ballast water of these vessels. By 1951, with completion of the Delta-Mendota Canal, the Delta was forever changed. This federal project for moving water to California’s Central Valley farms was the start of large-scale water supply infra

s tructure that would, with the addition of the State Water Project (SWP) and other smaller projects, evolve into today’s multibillion dollar system.

The Delta was formally defined in the Delta Protection Act of1959 (California Water Code Section 12220) and is composed of The Uplands Zone (lands above the 5-foot elevation contour) and the Lowlands Zone (lands at or below the 5-foot contour line). The statutory Delta Boundary that defines the Legal Delta is shown in Figure 12-1.

T his massive network of canals, levees, pumps, and fish screens moves water to farms, industries, and residents hundreds of miles from the Delta. What was once a continually changing tidal marsh with a rich variety of thriving, native species is now a complex maze of natural and man-made resources providing multiple benefits to the California economy.
The challenge the region faces in the 21st century is how to sustain the viability of these resources while demand for them continues to grow.California Water Plan Update 2005

**Volume 3** Regional Reports 212 

### Land Use The vast majority of the Delta land is agricultural (about 538,000 acres). These acres are among the most highly productive in the world. Open water covers about 60,000 acres, while urban and commercial property comprises approximately 64,000 acres. The remainder of the region presently consists of undeveloped natural plant vegetation. 

### PopulationThe legal Delta encompasses portions of six counties: Alame da, Contra Costa, Sacramento, San Joaquin, Solano andYolo. According to the census figures used in the 1995 Sacramento-San Joaquin Delta Atlas, the population in the Delta was an estimated 410,000 in 1990. A more recent estimate was obtained using data from the California State Census DataCenter for areas of these counties within the legal Delta, indicating that about 462,000 people resided in the Delta region as of the 2000 Census. Figure 12-2 shows a map of population estimates for each of the county areas within the legal Delta. Rapid growth is occurring in urban areas in and surrounding the Delta, especially in Elk Grove (27.0 percent growth per year – the highest growth rate in California), Tracy (5.9 percent per year), Brentwood (12.3 percent per year), and Rio Vista (11.1 percent per year) 1

. 

### Water Use Water use in the Delta region is mostly agricultural, with over 4,000 cubic feet per second of surface water diversions usedto irrigate crops during peak summer months. Irrigation diversions from about 1,800 sites in the Delta total about 1 million acre-feet annually. The main crops grown in the Delta are corn, alfalfa, other grains, tomatoes, and safflower. Grapes are being harvested in increasing numbers within the Delta region, and are quickly becoming one of the primary crops. Table 12-1 shows the approximate number of acres planted in various crops within the Delta Service Area and the associated applied water demand, as of year 2000. The Delta is at the confluence of the Sacramento and San Joaquin rivers. Its network of waterways conveys runoff toward San Francisco Bay and the Pacific Ocean to the west. (Photo courtesy of NASA)

1 G rowth rates are for the period between Jan. 1, 2003, and Jan. 1, 2004, and are from the California Department of Finance, E-1 City Populat ion Estimates, May 5, 2004.312 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005

County People Delta Region Population (Estimate - Year 2000) Legal Delta Boundary

Alameda
Contra Costa
Sacramento San Joaquin Solano Yolo Total 173 175,011 57,707 205,481 1,353 22,055 461,780 SOLANO

CONTRA COSTA SACRAMENTO

ALAMEDA SAN JOAQUIN YOLO **Figure 12-2 Delta region population**

Data from California Department of Finance provide decadal population from 1960 to 2000 and population projection for 2030 for Sacramento-San Joaquin Delta.California Water Plan Update 2005

**Volume 3** Regional Reports 412 Most Delta farms use water taken directly from Delta sloughs and rivers under riparian water rights, and drainage water from the islands is pumped back into the Delta waterways. Small communities in the Delta primarily use groundwater wells for their water needs, and urban water use in the Delta only accounts for a small percentage of the total developed supply 2 . The remaining portion of water in the Delta is either used by other forms of evapotranspiration or contributes to Delta outfl ow, through which it can provide wildlife habitat and salinity control benefi ts. Recreation water uses do not have a large affect on the Delta water balance, but are still important in the Delta, with an estimated 12 million “user days” 3 recorded each year for recreation purposes. 

### Water Exported from the DeltaThe Delta is the major source of fresh water to the San Francisco Bay and provides a portion of the water supply for many other communities in the bay region. Water from the Delta supplies drinking water for over two-thirds of the state’s population (over 23 million people) and irrigation water for more than 3-million acres of farmland statewide. The largest source of water for the Delta is the Sacramento River, which transports about 18.3 million acre-feet into the Delta in an average year. Additional fl ows from the Yolo Bypass and the San Joaquin River bring in an average of 5.8 million acre-feet, with precipitation adding about another 1 million acre-feet.Larger diversions in the Delta include the SWP (Banks Pump**Table 12-1 Crop Acreage and Applied Water Demand in the Delta Service Area as of 2000 (DWR Central Dist. 2004)** 

**Crop 1,000 Acres**  **Applied Water (TAF)**

Corn 113.2 325 Alfalfa 55.1 298 Other Grains 47.2 51 Processed Tomatoes 36.2 117 Safflower 33.8 26 Pasture 32.4 192 Vine Crops (grapes) 23.6 42 Other Truck Crops (strawberries, chili, etc.) 21.4 56 Other Deciduous Crops (apples, etc.) 18.3 78 Dry Beans 10.2 26 Other Field Crops 9.2 24 Fresh Market Tomatoes 6.6 16 Sugar beets 6.5 28 Cucurbits (cucumbers, gourds, melons, pumpkins) 4.7 10 Potatoes 3.9 12 Almonds, Pistachios 1.8 7 Rice 0.9 5 Onion and Garlic 0.6 2 Subtropical Crops (citrus, kiwis, etc.) 0.1 0.3 TOT AL 1 425.7 1,315.3

1 The total crop acreage listed here (425,700 acres) is less t han the 538,000 acres of agricultural land listed in the Delta Atlas (1991 land survey) for several reasons. The 2000 level in Table 12-1 only includes planted irrigated acres while the 1991 number includes other types of agricultural land, and the 2000 data is for the Delta Service Area – a smaller area than the Legal Delta used in the Delta Atlas. Urbanization of agricultural lands and weather conditions at the time of surveys are among the other reasons.

2 One important exception is the Contra Costa Water District, which provides treated Delta surface water to roughly 500,000 people, but not all of the serviced population is within the Legal Delta. 3 A “user day” is a measure of the number of people visiting or using a site over part or all of a given day. Since some recreation users will visit recreation areas more than once each year, the total number of people using recreation facilities over a year in the Delta is less than 12 million.512 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005

ing Plant and the North Bay Aqueduct), CVP (Tracy Pumping Plant), and Contra Costa Water District, which withdraw about 3.7 million, 2.5 million, and 126 thousand acre-feet in an average year, respectively. Figure 12-1 shows the primary locations and amounts of Delta infl ows, outfl ows and exports, as they occurred in water year 2000. Table 12-2 summarizes the Delta water balance for years 1998 (wet), 2000 (average), and 2001 (a dry year) and identifi es the major water inputs and outputs for the Delta.


### Water Standards Requirements of the State Water Resource Control Board (SWRCB) govern the release of upstream fl ows and curtailment of export pumping to maintain Delta water quality and outfl ow requirements for the San Francisco Bay. The fi rst water quality standards for the Delta were adopted in May 1967, when the State Water Rights Board (predecessor to the SWRCB) released Water Right Decision 1275, approving water rights for the SWP while setting agricultural salinity standards as terms and conditions. These requirements were altered in 1971 under SWRCB Decision 1379 (D-1379), which added standards that the CVP and SWP are to meet for non-consumptive uses (water dedicated to fi sh and wildlife), along with agricultural, municipal, and industrial consumptive use standards. In 1978, the SWRCB issued D-1485 and the 1978 Delta Plan, which together revised fl ow and salinity standards and required the US Bureau of Reclamation (USBR) and Department of Water Resources (DWR) to reduce pumping, release stored water upstream, or both when needed to meet the standards. **Figure 12-3 CALFED objectives**

**Water Supply Reliability**  **Levee System Integrity** 

**Water Quality Ecosystem**  **Restoration**California Water Plan Update 2005

**Volume 3** Regional Reports 612 In 1986, Congress passed the CVP-SWP Coordinated Operation Agreement (Title I of Public Law 99-546), requiring that the CVP be operated in coordination with the SWP to meet state water quality standards. Also in 1986, the Supreme Court upheld the Racanelli Decision, which recognized SWRCB authority and discretion over water rights and water quality issues, including authority over CVP operations. As a result of increasing use of Delta waters combined with escalating environmental and fi shery problems, the SWRCB adopted a new Bay-Delta Plan in 1991, which included objectives for salinity, dissolved oxygen, and temperature. The United States Environmental Protection Agency (EPA) followed with federal standards for the Estuary through EPA regulations in 1994. In December of 1999, theSWRCB issued a new Decision 1641 as a part of the1995 BayDelta Water Quality Control Plan, which replaced earlier Delta standards and conditioned the water rights permits of the SWP and CVP to implement the new objectives. The requirements set in D-1641 covered Phases 1 – 7 of the Bay-Delta Water Rights Hearings. In April of 2001, the SWRCB went on to adopt Water Rights Order 2001-05, which facilitates negotiationsto settle the responsibilities for implementing and maintaining the 1995 WQCP.
Currently the SWP and the CVP coordinate project operations to maintain the standards established by D-1641, by releasing water from upstream reservoirs for Delta outfl ow requirements, and by curtailing export pumping at the SWP Banks and CVP Tracy Pumping Plants during specifi edtime periods. This combination of Delta outflow requirements and export pumping limitations impose the most diffi cult challenges to the process of transporting water from upstream reservoirs to meet water needs in the San Joaquin Valley, San Francisco Bay Area, and Southern California.


## CALFED Bay-Delta Program The mission of the CALFED Bay-Delta Program is to develop and implement a long-term, comprehensive plan that will restore ecological health and improve water management for benefi cial uses of the Sacramento – San Joaquin Bay-Delta system. The plan was adopted by CALFED agencies when they signed the Record of Decision on August 28, 2000, approving a 30-year comprehensive plan. The ROD identifi es priorities for implementing the plan for the fi rst seven years and describes additional actions complementary to the plan. Since the ROD was adopted, CALFED agencies have been investing in collaborative regional projects that provide local benefi ts while helping achieve overall program objectives. 

### Table 12-2 **Water Balance for the Delta Region (IEP Dayflow Data TAF)** 1998 (wet) 2000 (average) 2001 (dry) **Water Entering the Region** Precipitation 1,421 954 762 Sacramento River 28,964 18,327 10,499 Yolo Bypass (incl. Sac. Weir spill and South Putah Cr.) 8,980 2,956 366 San Joaquin River 8,441 2,841 1,729 Cosumnes River 785 372 116 Mokelumne River 969 360 127 Misc. Eastside Tribs. 339 344 128 

### Total 49,899 **26,155 13,727 Water Leaving the Region**  Consumptive Use (Gross Channel Depletion for Ag, M&I, Wetlands, ET) 1,688 1,690 1,688 SWP Exports Banks Pumping Plant 2,111 3,666 2,599 North Bay Aqueduct 39 47 45 CVP Exports 2,470 2,482 2,328 Contra Costa WD Exports 160 126 104 Outflow to Bay/Ocean 43,430 18,144 6,963 

### Total 49,899 26,155 13,727712 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005

Some of the major water-related challenges facing the Deltahave been summarized by the Bay-Delta Authority as “priorities and issues” for the region:

• Restore healthy ecosystems to benefit native species.

• Preserve a viable agricultural base.

• Maintain strong levees.

• Protect water quality for agricultural and urban water

users in and around the Delta.

• Protect and increase recreational opportunities.

T hese goals incorporate the four broad CALFED resource management objectives of water supply reliability, water quality, ecosystem restoration, and levee system integrity, and respond to concerns expressed by stakeholders in the Delta and other regions of the state (Figure 12-3).

A uthorized by the Delta Protection Act of 1992, the Delta Protection Commission (DPC) is the regional entity charged with protecting the natural, agricultural, and recreational resources of the Delta. The Act required the DPC to develop and adopt a resource management plan for the primary zone of the Delta (defined in Public Resources Code Section 29728). The DPC’s mission is to guide the protection of the Delta’s unique natural quality, cultural viability, economic viability, and recreational opportunities using three main objectives:

• Protection, maintenance, and enhancement and restor ation of the overall quality of the Delta environment including agriculture, wildlife habitat, and recreational activities;

• Assurance of orderly, balanced conservation and development of Delta land resources; and

• Improvement of flood protection to ensure an increased

level of public health and safety

. The CALFED Program, its implementing agencies, and the DPC recognize that activities of the CALFED Ecosystem Restoration, Conveyance, Storage, and Levee System Integrity program elements must be in concert with the Delta region’s land use and recreation objectives. Therefore, CALFED and the DPC coordinate activities on a regular basis. 

## State of the Region The Delta is a focal point for water management, ecosystem restoration, land use planning, and other major initiatives in California. The Delta Improvements Package, which has been identified as a critical CALFED implementation mechanism, is focused on actions within the Delta. Over $155 million has already been spent on ecosystem projects, studies, and acquisition within the Delta through this Bay-Delta Program. Urban encroachment in the Delta is becoming a critical issue, and some of the fastest growing communities in the state can be found within and around the Legal Delta. Concerns over increased water diversions from northern to southern Califor

nia are based on pumping operations within the Delta. TheDelta is, and will likely continue to be, a hot spot for both controversy and innovation in ter ms of resource management.
Two of the agencies identified with key planning roles in the Delta are the California Bay-Delta Authority and the Delta Protection Commission (DPC). The Bay-Delta Authority is responsible for implementing the Bay-Delta Program (Box 12-1) . The DPC comments on applications for CALFED eco

s ystem restoration grants that affect the Delta and participates in meetings with other CALFED agencies to provide input toCALFED Program management decisions. DPC staff also provides input to the following BDPAC subcommittees: Working Landscapes Subcommittee (created to pursue partnerships with private landowners in meeting CALFED ecosystem, water quality, levee, and water supply reliability goals); the Delta Levees and Habitat Advisory Committee; and the Ecosystem Restoration Subcommittee. Many projects and programs are being carried out to address local and statewide needs related to the Delta. The stakeholders involved in Delta imple

mentation issues are increasingly aware of how complex and interrelated solutions must be to avoid adverse impacts to other stakeholders and to provide long-term, comprehensive management of Delta land and water resources. Some of the major implementation issues and achievements to date are summarized below.



## Box 12-1 California Bay-Delta Authority
The California Bay-Delta Authority officially became a State agency in January 2003. The authority oversees implementationof the CALFED Bay-Delta Program to improve water supplies in California and the health of the San Francisco Bay–Sacram ento/San Joaquin River Delta. The organization and focus of this Authority is being reviewed and changed in 2005.California Water Plan Update 2005

**Volume 3** Regional Reports 812 **Figure 12-4 Proposed Delta gates map**

Freeport Regional Water Project (Not on this map)

Delta Cross Channel and4 through delta conveyance

Stockton Ship Channel dissolved oxygen improvements

Agricultural barriers Fish barrier

Lower San Joaquin River water quality and flow improvements Central Valley Project pumps
Central Valley Project/ State Water Project Intertie State Water Project pumps Old River and Rock Slough water quality improvements Franks

Tract

San Luis low point (not on this map)912 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005



### Water Supply Reliability Because water users within the Delta divert directly from adjacent

c hannels running through the Delta, they normally have immed iate access to water. However, water levels in these channels are influenced by river inflows, ocean tidal levels, and CVP and SWP operations, especially diversions at the south Delta export pumps. Lower water levels in the south Delta channels can make it difficult for local irrigators to pump or siphon the water from the channels to their farmlands. In addition, the flow of water to the export pumps can sometimes draw water with a higher salinity into the south Delta from the western Delta.
To help address these water level problems, CALFED agencies provide assistance in creating temporary barriers in portions of the Delta to raise water levels and improve water quality for irrigators. The Environmental Water Account helps improve water supply reliability by acquiring water from willing sellers to compensate for lost supplies during periods of export pumping curtailment for fish protection.
Longer-term solutions involving the installation of flow controlgates are being analyzed as part of the South Delta Improvem ents Program(see figure 12-4), which would eventually make possible increased pumping operations at Banks Pumping Plant to 8,500 cubic feet per second during acceptable periods of theyear. Design and environmental reviews of the SDIP are ongoi ng. Other water supply activities in the Delta currently under investigation by CALFED include: adding an intertie between the CVP and SWP canals south of the Delta; re-operating the Delta Cross-Channel (DCC) for the benefit of fish and water quality; and feasibility studies for an in-Delta storage project. Thus far, modeling studies for the CVP-SWP intertie and two years of research experiments on DCC re-operation have been completed. In addition, a draft report about the engineering feasibility of the in-Delta storage project has been published for review and consideration. 

### Water QualityThe Delta is a source of drinking water for over 23 million Californians, which underscores the importance of carefully managing water quality in the region. Key drinking water constituents that are of concern are bromide and organic carbon, because they are known to contribute to the production of trihalomethanes (THMs) during the drinking water chlorination process. There are a wide range of water quality issues in the Delta, and several different initiatives have been organized in response. SalinityThe impact of salinity on water quality in the Delta is important and directly related to water supply reliability. The balance between ocean tides, river outflows, salinity input from agricultural and urban drainage, export pumping rates, and other factors directly impacts aquatic health in the Delta and the public health of those who use Delta drinking water. One problematic component of water salinity is bromide, which is known to produce trihalomethanes (THMs) during drinking water chlorination. THMs are known carcinogens and are subject to strict federal drinking water quality standards. South Delta agricultural diverters are often faced with high levels ofwater salinity, which can damage crops and reduce productivi ty. DWR’s South Delta Temporary Barriers Project is designedto limit saltwater intrusion into areas with agricultural diversions, while also raising Delta water levels (Figure 12-5).

Mercury Mercury can be found in waterways throughout the Delta as

a result of historical mining activities that were widespread throughout the Sacramento Valley, such that the entire Delta is presently on the SWRCB’s 303(d) list 4 for sources of mercury. Miners used mercury to separate gold from rock in the Coast Range, and abandoned gold and mercury mines continue toleach mercury today. While mercury in its natural form is usually not easily transmitted into living organisms, some natural processes encourage conversion to methyl mercury, which is a powerful neurotoxin that accumulates in fish tissue and is harmful to animals and humans. Restoration of wetlands has faced increasing scrutiny because the conversion of mercury to methylmercury (that is, methylation) may be encouraged by certain natural wetland processes.
In response to this threat, research is now under way to study mercury transport, how to reduce the risks associated withhuman exposure, and potential methods to reduce methy lation—particularly in restoration activities. The CALFED Ecosystem Restoration Program (ERP) has invested over $4 million in two research projects that investigated a wide variety of mercury issues, and culminated in a “mercury strategy” developed by a team of independent mercury experts. The new strategy includes recommendations for how to carry out future restoration work while minimizing methylation impacts. A more intensive follow-up study is now under way to expand on this knowledge and reduce the levels of uncertainty.

4 The Clean Water Act requires that states and territories identify impaired and threatened water bodies that are not expected to meet water quality standards, as outlined in Section 303(d) of the Act. These lists result in the development of Total Maximum Daily Loads (TMDLs), which establish the maximum amount of pollutants the water body can receive while still meeting water quality standards.California Water Plan Update 2005

**Volume 3** Regional Reports 1012 The Department of Conservation with assistance from ERP has created two workgroups to deal with mercury source issues related to abandoned mines. A “fi sh consumption workgroup”has also been organized to coordinate funding and management efforts between the various agencies in order to educate people about reducing consumption risks resulting from mercury contamination. Other agencies and organizations working to address mercury include the Delta Tributary Mercury Council, the Central Valley Regional Water Quality Control Board, the San Francisco Bay Regional Monitoring Program, the Offi ce of Environmental Health Hazard Assessment (OEHHA), the Department of Health Services, the San Francisco Bay Regional Water Quality Control Board, EPA, the Sierra Trinity Abandoned Mine Lands Agency Group, and the Bay-Delta Public Advisory Subcommittee on Environmental Justice.

Dissolved Oxygen (DO) Current water quality standards call for at least 5 milligrams per liter of dissolved oxygen in Delta water to protect aquatic organisms (including fi sh), allow for successful fi sh reproduction and juvenile rearing, and prevent odor problems. Discharges into the San Joaquin River and the Delta sometimes contain material with a high biochemical oxygen demand or a high nutrient level, which can encourage algae growth and trigger subsequent oxygen depletion. These discharges, along with depleted freshwater fl ows, channel confi guration, and water temperatures, have resulted in isolated areas in the Delta with DO levels below the current standard. On the San Joaquin River, low DO levels may pose a barrier to fall-run salmon migrating upstream to spawn.

T he DO problem is not a new phenomenon, and has been studied for some time. DWR and the Inter-agency Ecological Program (IEP) have maintained monitoring efforts on the San Joaquin River and the Stockton Deep Water Channel since the 1980s. CALFED ERP expenditures of about $4 million have been spent on monitoring and research activities related to DO, including development of models to better understand thermal stratifi cation in the San Joaquin River. ERP has also begun a feasibility study forusing water aeration techniques to increase DO levels, and several aeration and nonaeration methods are under development.

Organic Carbon (TOC) Organic carbon is itself not a harmful constituent—In fact it is essential for aquatic life (Box 12-2). Problems occur when water containing high levels of organic carbon is treated in **Figure 12-5 Delta Improvements Program**1112 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005

drinking water treatment plants, which use chemicals to inactivate harmful pathogens. Some forms of organic carbon react with these beneficial disinfection agents, such as chlorine, and produce potentially carcinogenic disinfection byproducts (for example, trihalomethanes). Since wetland restoration efforts could potentially increase the level of vegetation and organiccarbon in Delta water supplies, there may be conflicting object ives between ecosystem restoration and water quality initiatives, as is also the case with mercury.
Because some organic carbon processes are still poorly understood, much of the current work is focused on investigating how carbon is used in the aquatic food web and how natural and anthropogenic factors affect the type and amount of organic carbon released into the system. As part of approximately $10 million in funds designated for CALFED ERP organic carbon projects, one research project, funded jointly with the CALFED Drinking Water Quality Program, is attempting to determine if coagulants could be used to remove organic carbon from Delta island drainage. The U.S. Geological Survey (USGS) is spearheading much of the organic carbon efforts, working in conjunction with ERP. The CALFED DWQ Program is also involved, investing $1.7 million in 2003 in four drinking water quality projects to monitor and assess organic carbon sourcesand processes in the Delta. DWR’s Municipal Water Quality Investigations (MWQI) Program has also funded organic carbon projects in the Delta, including real-time monitoring, source assessment, and studies of byproduct formation potential.

Selenium Selenium enters the Delta region from multiple sources, i nclud ing groundwater discharges from selenium-containing soils, agricultural runoff, and refinery water input from the San Francisco Bay. Selenium, like mercury, bioaccumulates in aquatic life and has been shown to have negative affects on fish and waterfowl. High selenium concentrations could cause disruptions in drinking water and agricultural water deliveries, and are often correlated with high salinity levels as well. C ALFED’s ERP is currently implementing several projects to study the sources, transport, and biological affects of selenium in the Delta. One ERP project is also examining the potential for using bacteria to reduce selenium contamination in agricultural return water. The DWQ Program is also coordinating projects that focus on selenium in irrigation drainage water from the San Joaquin Valley.
Other agencies involved with the selenium issue include the USGS, which has worked on ERP projects and other initiatives to forecast selenium discharges and study its affects on the aquatic environment. In the San Joaquin Valley, USBR and the San Luis & Delta Mendota Water Authority have successfully developedthe Grasslands Bypass Project to reduce selenium loads in agricultural drainage water before it enters the San Joaquin River.Both the Central Valley and San Francisco Regional Water Quality Control Boards are now developing Total Maximum Daily Loads (TMDLs) for the San Joaquin River and San Francisco Bay,respectively. The University of California, Davis has also participated in selenium research, particularly with bioaccumulation and the use of microalgae to treat agricultural drainage water.

Pesticides Pesticides include insecticides, herbicides, fungicides, and other substances used to prevent, destroy, repel, or prevent pests. In the Delta, several types of chemical pesticides are widespread, including organophosphates, organochlorines, and pyrethroids. Each of these materials has certain risks for humans and aquatic organisms because they are, by design, meant to disrupt biological processes 5

.Organophosphates (also called organophosphorous pesticides) affect the nervous system and were used in World War II as nerve agents in addition to being used as insecticides(such as chlorpyrifos and diazinon). While usually not persistent in the environment, organophosphates have been found in the Bay-Delta watershed and could impact the distribution and abundance of aquatic species. Organochlorines, which



## Box 12-2 Organic Carbon
Organic carbon can be found in different forms in nature, including dissolved organic carbon (DOC) and particulate organic carbon. Total organic carbon (TOC) is a measurement of all forms of organic carbon, and is usually primarily made up of DOC. The sources and fate of DOC and TOC are nearly identical, and the ter ms are often used interchangeably.

5 Much of the pesticide information is taken from U.S. EPA Pesticide Program Web site (www.epa.gov/pesticides).California Water Plan Update 2005

**Volume 3** Regional Reports 1212 include DDT and chlordane, were used extensively in the past but now are much less widely used because of their toxicity and persistence. Like mercury, organochlorines accumulate in fish tissue and could contaminate humans and animals who consume them. Pyrethroids are synthetic versions of a naturally occurring pesticide in chrysanthemums, and some forms can be extremely toxic to the nervous systems of fish and invertebrates. Pyrethroids are becoming more widely used, but current monitoring equipment is unable to measure concentrations in the environment.

Several projects are now under way to evaluate practices that could reduce pesticide and fertilizer use in the Delta, limit urbanpesticide applications in Sacramento and Contra Costa count ies, and to study the impact of pesticides on aquatic life. CALFED ERP is involved with many of these efforts, along with a study todevelop water quality criteria for the organophosphates diazinon and chlorpyrifos.

Toxicity of Unknown Origin In addition to the above described constituents that are known
to impact organisms in the Delta, there is the possibility that other substances yet to be identified may be contributing to toxicity problems. The CALFED ERP is funding several projectsto monitor and attempt to identify the source of certain episodes of toxicity in the Delta. Studies regarding splittail and delta smelt exposures to unknown toxics are being conducted as part of the ERP projects. An implementation plan is alsobeing developed to reduce toxicity associated with these asof-yet unknown materials.

There are many other constituents and issues related to water quality that are important in the Delta region. Like some formsof organic carbon, bromide, which is a component of salinity

, can produce disinfection byproducts when treated with certain, necessary disinfection processes used in domestic water treatment plants. Various pathogens are also present in Delta waterways, and the CALFED DWQ Program is leading several projects to assess pathogen fate and transport fromhuman and animal sources, including animal feeding operations and recreational water use. DWR’s MWQI Program is also funding pathogen studies related to hydrostatic pressure,pathogen survivability, and confined animal feeding operations. Sediment is another issue of concern, particularly with respect to dredging operations to maintain the Stockton andSacramento deepwater ports, which may re-suspend contaminants (from sediment) that are toxic to aquatic life. The US Forest Service has been involved in projects to reduce sediment loading, along with the CALFED watersheds, DWQ, and ERP programs. In addition, studies are under way to model and evaluate water quality improvements that could achieved from proposed Delta conveyance and storage alternatives.


### Ecosystem Restoration Over the past century, the health of the Delta ecosystem has declined in response to the reduction of habitat for both aquatic and terrestrial biota. Remaining habitat quality has also declined due to several factors including water diversions, toxic pollutants, and the introduction of exotic species. In fact, few aquatic ecosystems in North America have been invaded and changed by as many exotic species as those in the Bay-Delta. The Delta no longer provides the broad diversity or quality of habitat necessary to maintain ecological functions and support healthy populations of native plants and animals. Conversion of agricultural land to accommodate ecosystem improvements under the Bay-Delta Program could provide some relief, but these actions are also a major concern for Delta agricultural interests, who rely on the land for their economic survival.
During the past several decades, as water diversions and the recognition of environmental water needs have increased, so have the conflicts among different interests. Water flow and timing requirements have been established for certain fish andwildlife species in response to declining fish and wildlife populat ions. These requirements restrict the amount of water that can be diverted from the Delta, and constrain the time over which these withdrawals can be made. Over the past decade, a number of other protective actions have been implemented to protectfish and wildlife, including the Central Valley Project Improvement Act (CVPIA) and the 1994 Bay-Delta Accord. While the programs that have resulted have helped provide flows and habitat essential to endangered and threatened species, they have also reduced the ability of the CVP and SWP to meet thewater demand of their contractors at the time of year that supplies are needed. This timing issue has contributed to the false perception of a zero-sum game, in which ecosystem or water supply interests can only benefit to the other’s detriment, and has created heightened tension between various groups.
To address ecosystem health issues, the CALFED ERP hasinvested in cooperative projects such as wildlife-friendly agric ultural practices, which have shown that different interest groups do not have to compete against each other to prosper in the Delta. Other ecosystem efforts underway include wetlands protection studies, invasive species eradication initiatives, and fish studies to monitor the effects of pesticides on aquatic health. About $155 million has been spent on 107 ecosystem projects1312 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005

in the Delta, representing one of the largest investments in ecos ystem restoration in the United States. The ERP has also funded major studies to examine the effects of pesticides on fish in the Bay-Delta system and the release of dissolved organic carbon and methyl mercury from restored wetlands.
Closely associated with ERP, the CALFED Multi-species Conserv ation Strategy (MSCS) is a comprehensive regulatory plan for the CALFED Program developed in accordance with the federal Endangered Species Act (ESA), the California ESA (CESA), and the Natural Community Conservation Planning Act (NCCPA). The MSCS establishes the programmatic State and federal regulatory requirements for numerous species and habitat typeswithin the MSCS-ERP Focus Area. By implementing and adheri ng to the MSCS, the CALFED Program can be implemented in compliance with the ESA, CESA, and NCCPA.


### Levee System Integrity The Delta levees confine flow to channels and protect Delta lands from daily flooding by the tidal fluctuations. Without the levees, the Delta would be a 740,000-acre brackish inland sea. In the late 1800s and early 1900s, levees were originally built using the peat soils native to the Delta. This material is weak and highly compressible, which has left many of the levees vulnerable to failure, especially during earthquakes or floods.
The high organic content in the soil contributes to rapid decomposition and settling, and decreases the integrity of the levee structures and their ability to hold back water flows. Delta island farmland, residential land and homes, wildlife habitat, and critical infrastructure could be flooded as a result of a levee failure. Flooding in the Delta has historically resulted in millions of dollars of damages. The State formed a partnership with local agencies in 1986 to improve the condition of the extensive Delta levee system. As a result of that partnership, a new levee maintenance assistance program was implemented, and incidents of levee failure from winter floods have decreased compared to prior years.

Levee failures during the summer (the most recent in June 3, 2004) or fall that inundate islands under non-flood conditions can also cause impacts by pulling salty water into the Delta from San Francisco Bay. The resulting increased salinity in the Delta could shut down CVP and SWP exports from the Delta until fresh water inflows return. Increased salinity in the Delta would be of particular concern in a low water year, when less freshwater is available to flush the salt out of the Delta. This damaging scenario occurred in 1972, when the Brannan-Andrus Island levee failed, resulting in the depletion of about 400,000 acre-feet of water supplies and requiring the removal of about 50 tons of salt. Long-term flooding of specific Delta islands could also affect water quality over a longer time horizon by changing the rate of saltwater intrusion and the area of the mixing zone. A long interruption of water supply for in-Delta uses and exports would affect both urban and agricultural users, until the salt water could be flushed from the Delta channels.
CALFED’s Levee System Integrity efforts work in conjunction with the DWR Delta Levees Program to maintain and strengthen the levee system. DWR in turn works with local groups and agencies, particularly with reclamation boards, to assist in the planning and funding of levee projects. Under Base Level Protection efforts, non-project levees 6 are maintained and strengthened, with the ultimate goal of bringing all appropriate levies to auniform base level of protection. DWR also provides partial funding and assistance for CALFED’s Special Improvement Projects, which help establish protection above base level standards inregions with particular public interests – such as highly popul ated islands. Special cost share requirements are used with levee projects, which allocate costs between the local participants and the State, and DWR oversees two funding mechanisms that are used to provide the State contribution.

In addition to levee maintenance and enlargement, other leveerelated efforts include levee subsidence studies, emergency response coordination (including the distribution of flood fight boxes containing emergency materials such as sandbags and hand tools), analysis of levee risks associated with seismic events, and dredged material management. The Levee System Integrityefforts have incorporated a number of ecosystem-related projects, such as the habitat development work currently underway at Decker Island, and certain provisions of the Program require that levee activities must result in net habitat improvement. Other agencies involved with the Delta Levee efforts include the U.S. Army Corps of Engineers and the California Department of Fish and Game, which serve along with DWR as Implementing Agencies of the Levee System Integrity Program.



### RecreationAccording to figures used in the 1995 Sacramento-San Joaquin Delta Atlas, the Delta is estimated to support more than 12 million recreational user days a year. According to surveys conducted in 1996 by the Delta Protection Commission (DPC) and the Department of Parks and Recreation (DPR), 23.5

6 A “non-project” levee is defined by State Water Code as “a local flood control levee in the delta that is not a project facility under the State Water Resources Law of 1945”.California Water Plan Update 2005

**Volume 3** Regional Reports 1412 percent of registered boat owners and 23 percent of licensed anglers in the State of California participated in recreation activities within the Delta. Fishing, cruising, water skiing, swimming, and sailing are all popular ways of recreating in the Delta, as well as sightseeing and wildlife viewing. As a result of the growing population within the Delta and across the State, the popularity and use of the Delta as a major recreational location is expected to increase.

The DPC, DPR, and the Department of Boating and Waterways (DBW) have important oversight and regulatory roles for Delta recreation. In addition to the 1996 surveys, DBW cooperatedwith DPC’s Recreation Citizen’s Advisory Committee in December of 2002 to produce a Boating Needs Assessment, which inventoried existing recreational boating infrastructure in the Delta and projected future boating needs.

This assessment followed a 1995 Report conducted by DPC,which made recommendations to improve recreation condit ions and access. A detailed Delta Recreation Master Planis currently being prepared by the Delta Protection Commiss ion, with assistance from DPR and the California Coastal Commission. The first phase of this study addresses Delta user and facility needs for water-based and water-enhanced recreation. The resulting estimates of recreation use in theDelta confirm that recreation is a key component in management of Delta resources. When completed, the second phase of this master plan will focus more on land-based recreation needs, and present a “big picture” summary of all recreationwithin the Delta. As a public resource and economic bene fit, recreation opportunities in the Delta are highly valued. 

## Looking to the Future On a long-term continuing basis, a wide variety of studies and projects are being undertaken to protect water quality, maintain and improve ecosystem health, maintain the stability of levees, and improve water supply reliability (Box 12-3). Most of these activities are being conducted by state and federal agencies in partnership with local landowners and Delta interests, and many of the major projects are critical to implementing the CALFED Bay-Delta Program Plan.

Ef forts are continuing to develop major programs and projects that are intended to address long-standing Delta water management issues. Interest groups and government agencies are grappling with how to package interdependent actions and programs in a manner that will protect the Delta’s water quality and ecosystem, and keep the levee system stable. Among the many challenges facing this effort is the issue of how to reconcile the engineering and technical realities with the economic and political realities.

C ALFED implementing agencies, in conjunction with other Delta interests, are attempting to move critical projects forward through the Delta Improvements Package. These projects are outlined in the CALFED Bay-Delta Program Record of Decision (ROD), which calls for balanced implementation of CALFED program elements. In the Delta Region, implementation of the CALFED resource management objectives includes the following priorities: improving the environment so that threatened and endangered species populations can recover; making continual improvements in Delta water quality; increasing conveyance



## Box 12-3 Ongoing Planning Efforts

• American Farmland Trust study of Delta agriculture.

• Delta Regional Ecosystem Restoration Implementation Plan (DRERIP) for the Delta, lead by DFG.

• SAFCA study of new flood control projects for Sacramento and West Sacramento in Yolo Bypass.

• Yolo Flyway Center – proposed public education facility adjacent to Yolo Bypass.

• Delta Science Center – proposed public education facility at Big Break Regional Shoreline (East Bay Regional Park

District).

• Rio Vista--proposed public education and recreation facility at former military property recently transferred to

City of Rio V ista.

• New Research Facility proposed by CALFED Science Consortium at former military property recently transferred

to City of Rio V ista.

• Delta Protection Commission study of Delta recreation

• California Bay-Delta Authority, various investigations for implementation of the Bay-Delta Plan1512 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005

capacity of the Delta pumping plants (to improve water supplyreliability statewide); assuring adequate water levels for agric ultural diverters; and improving levee system integrity.
The Delta Improvements Package is a framework for moving forward in several of these areas simultaneously while makingconsiderations beyond what is required by the ROD. For examp le, although the CALFED ROD did not require that Delta water quality improvements occur before increasing the pumping capacity of Delta pumping plants, DWR and USBR are working with Delta interests to improve salinity levels in the south Delta while proceeding with studies for the SDIP, which is included as a part of the overall Delta Improvements Package.
The following is a summary of major programs and actions that are critical to achieving desired benefits for the Deltaregion. In addition to listing major project milestones establ ished for Stage 1 (years 1 through 7) of the CALFED Bay-Delta Program, other Delta initiatives, including recreation efforts, are also included. 

### Water Supply Reliability Many of the proposed future water supply activities in theDelta are included as part of the Delta Improvements Packa ge, while others are being considered independently as described below.
Delta Improvements Package The Delta Improvements Package (DIP) could eventually include several components related to water supply reliability:

• South Delta Improvements Project/8,500 cfs – Under the SDIP , permitted pumping at Banks Pumping Plant would be increased to 8,500 cfs. To mitigate the affects of the higher pumping rate, interim actions would be taken to maintain water levels for South Delta agriculture, protect water quality, prevent fish entrainment, and comply with environmental obligations. More permanent mitigation measures would include the construction of permanent operable barriers, development of a comprehensive San Joaquin River Salinity Management Plan, construction of water quality projects for Old River and Rock Slough,complying with Natural Community Conservation Plann ing Act 7 (NCCPA) and ESA requirements, and developing a long-ter m Environmental Water Account. • SWP/CVP Integration Plan – Excess capacity at Banks P umping Plant, part of the SWP, could be used to convey up to 50,000 acre-feet of Level 2 CVP refuge water in return for using up to 37,000 acre-feet of CVP water to meet SWP in-basin water quality and flow requirements. These quantities could be raised if pumping at Banks is allowed to reach 8,500 cfs.

• SWP/CVP Intertie – SWP and CVP operations could be

m ore closely linked through the construction of an intertie between the California Aqueduct and the Delta-Mendota Canal just south of the Delta. This intertie would provide enhanced flexibility between the two systems, and create additional conveyance capacity for the CVP.
In-Delta Storage Project DWR and USBR are also investigating the In-Delta Storage Project as part of the Bay-Delta Program. The Project would include two storage islands (Webb Tract and Bacon Island) and two habitat islands (Holland Tract and Bouldin Island), and could provide for about 217,000 acre-feet of new storage for a wide variety of potential uses, including exports and Delta outflow.
A State feasibility study for the project was completed in January 2004, and a final EIR/EIS is anticipated in December 2005. Initial estimates from the feasibility study showed an equivalent annual cost for the project of $60 million, with annual watersupply benefits between $23 and 26 million and another $2 mill ion in annual recreation, flood damage reduction and avoided levee maintenance benefits. Evaluations on how In-Delta Storage would impact organic carbon and salinity levels in the Delta are ongoing, and will be important in determining the overall feasibility of the project.

Los Vaqueros Reservoir Expansion Contra Costa Water District (CCWD) owns and operates Los V

aqueros Reservoir, a 100,000 acre-foot, offstream reservoir that, while located outside of the Legal Delta, diverts water from the Delta. Planning studies are underway to evaluate expansion of this reservoir’s capacity up to a maximum of 500,000 acre-feet through the construction of a new, larger dam. Depending on how the reservoir would be operated, a portion of the storage at Los Vaqueros could be used by the Environmental Water Account. CCWD customers voted in March 2004 to continue planning studies for the project, and final feasibility studies and environmental documentation are scheduled for completion by the winter of 2007.

7 California Department of Fish and Game Code.California Water Plan Update 2005

**Volume 3** Regional Reports 1612 

### Water QualityProjects designed to improve Delta water quality are prominently included within the Delta Improvements Package, as well as in other initiatives. A few of the most important water quality efforts that can currently be identifi ed as important to the future of the Delta are listed below.
Delta Improvements Package A large number of water quality projects have been included i n the Delta Improvements Package, some of which were included in the CALFED ROD and others that were more recently conceived.

• South Delta Improvements Package/Permanent Operable B arriers – Permanent operable barriers would be required before full implementation of 8,500 cfs pumping capacity at SWP Banks Pumping Plant. One of the primary reasons for the barriers would be to improve water circulation and water levels within the south Delta.

• San Joaquin River Salinity Management Plan – To comply

w ith the salinity requirements in SWRCB Water RightDecision 1641, DWR and USBR are developing a comprehensive plan, in cooperation with SWRCB and the CentralValley Regional Water Quality Control Board. The proposed San Joaquin River Salinity Management Plan would address agricultural drainage issues, salt load reduction from Salt and Mud Sloughs, recirculation of Delta exports into the San Joaquin River, voluntary water transfers for **Figure 12-6 In - Delta Storage Project**1712 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005

quality benefits, and real-time water quality monitoring.

• Vernalis Flow Objectives – Water Right Decision 1641 also included flow requirements at Vernalis on the lower San Joaquin River, which have also been addressed in the Delta Improvements Package. The USBR and DWR, along withthe CALFED agencies in the Water Operations Managem ent Team, would work together to meet flow requirements that protect fish and wildlife dependent on San Joaquin River flows.

• Old River and Rock Slough Water Quality Improvement Projects – Before any permanent operable barriers are used, agricultural drains on the Veale and Byron Tracts would be relocated. In addition, efforts would be made to reduce seepage into the Contra Costa Canal to protect the quality of the District’s water supply.

• San Joaquin River Dissolved Oxygen – DWR and USBR, in coordination with other CALFED agencies and local participants, would develop a comprehensive strategy to alleviate dissolved oxygen problems in the Stockton Deep Water Channel. These improvements could go beyond water project obligations, and would be coordinated with SWRCB and Central Valley Regional Water Quality Control Board.

• Franks Tract – Salinity levels at the major export pumps in the Delta may be significantly reduced through water quality actions at Franks Tract (Box 12-4). Reconfiguration of levees and modification of water circulation are possible alternatives for the Franks Tract project. • Delta Cross Channel Program – Building on completed

s tudies of the Delta Cross Channel, USBR and other agencies would continue, under the Delta Improvements Package, to develop methods for improving central and south Delta water quality while encouraging fish passage around the channel.

• Relocation of CCWD Water Intake – If the Delta water quali ty improvements from the above measures do not provide acceptable continuous improvements in water quality, the State and federal agencies will evaluate alternatives to move the Contra Costa Canal intake to the lower part of Victoria Island. This project would require appropriate environmental review, as well as agreement on cost sharing requirements. CCWD is conducting studies to evaluate this location as an alternative point of diversion.

• Through-Delta Facility – As identified in the CALFED ROD,

a screened diversion facility on the Sacramento River could be used to move 4,000 cfs of water through the Delta to the Mokelumne River to enhance water quality. The Through-Delta Facility (TDF) could also have water supply and environmental benefits, although Delta salinity impacts could be difficult to predict due to the complex flow regime of the Delta. Overall impacts on water quality in the Delta will be dependent on other projects and operational strategies, such as how the Delta Cross Channel would be managed in conjunction with the TDF.



## Box 12-4 Franks Tract Description
Once a reclaimed tidal marsh, Franks Tract was flooded in 1938 following a levee breach, and has since become a focus of water supply and water quality initiatives in the Delta. Franks Tract is used for recreation purposes, and also plays an important role in Delta water circulation. Saline water from ocean tides tends to become “stuck” within the tract, creating water quality problems for the export pumps and the Delta as a whole. The proliferation of egeria densa, an invasive species known commonly as Brazilian waterweed, is also a problem in Franks Tract.
In response to these and other issues, DWR and the Bay-Delta Authority are conducting studies to see if levee modifications, salinity tidal gates, and other measures could be used not only to solve current problems, but to create additional benefits for the Delta. Recreation interests and state agencies have also identified potential sites for islands in the tract, which could be used for recreation and ecosystem habitat while providing erosion protection for the southern levees. The addition of trenches in certain segments could also enhance boating opportunities while limiting the spread of egeria densa, which requires shallow water for optimum growth.

T he CALFED Science Program and DWR’s Franks Tract Project are leading the way in developing alternatives to improve conditions in Franks Tract while providing new benefits for the Delta. CALFED efforts in the tract are ongoing, and a DWR-led feasibility study is now underway, with full implementation expected by 2011.California Water Plan Update 2005

**Volume 3** Regional Reports 1812 Delta Region Water Quality Management Plan This plan is being developed by Solana County Water Agency, CCWD, and the City of Stockton, all three of which are interestedin new water supply diversions from the Delta. In addition to evaluating the potential for additional Delta water intake structures, these entities are also investigating water treatment technologies and source water protection actions as part of management plan.

DWR MWQI Program The Municipal Water Quality Investigations (MWQI) Program under DWR investigates water quality issues for State Water Contractors and other Delta water users. Issues that MWQIintends to pursue in the near future are greater use of realtime data in modeling and O&M applications, expanded investigations into organic carbon loading from wetlands, and greater coordination with the CALFED Bay-Delta Public Advisory Committee’s Drinking Water Subcommittee.

CALFED Storage Projects Investigations are currently underway to determine if CALFEDstorage projects could be used to enhance water quality conditions in the Delta by releasing water of the appropriate temperature and quantity at the beneficial times, or used in lieu of surface diversions to maintain the quality of Delta inflows. Newreservoirs could also have negative water quality impacts, however , such as additional organic carbon input, and the overall affect will have to be considered for each project. 

### Ecosystem Restoration Ecosystem restoration efforts will continue to be critical in the future for the Delta. Many of the efforts listed here will also benefit as better scientific information is obtained to developspecific, quantitative habitat objectives for ecosystem restoration. The population objectives that are being developed for listed species of anadromous fish (via processes under theEndangered Species Act) will also be of use towards measuring the success of restoration ef forts.
Delta Improvements Package The Delta Improvements Package includes several programs with ecosystem restoration components. While this list is still under development, a preliminary outline is included here.

• OCAP ESA Consultation – DWR and USBR have prepared

a Biological Assessment for the Operations Criteria and Plan (OCAP), which provides a detailed explanation and analysis of the criteria and procedures used to coordinate operations of the SWP and CVP. USFWS and NOAA Fisheries will later respond with Biological Opinions based on the OCAP Biological Assessment, and DWR and USBR will continue to work with the federal agencies and the California Department of Fish and Game to develop future policies for integrated CVP/SWP operations.

• SDIP ESA Consultation – DWR and USBR are also working on an Action Specific Implementation Plan (ASIP) for species covered under the CALFED ROD Multi-species Conservation Strategy (MSCS). USFWS and NOAA Fisheries will review the SDIP Preliminary Biological Opinions and the ASIP to determine if SDIP consultation should be reinitiated, and DFG will review the ASIP to consider if it should receive Natural Community Conservation Plan (NCCP) authorization.

• Update of CALFED ROD Programmatic Regulatory Commitments – The CALFED ROD required that USFWS, NOAA Fisheries, and DFG review and approve the programmatic regulatory commitments established in the ROD by September 30, 2004. A Notice of Determination for the Environmental Water Account EIS/EIR was signed in 2004, the Record of Decision was signed, and the Notice of Determination was issued in October 2004. Implementation of the EWA through 2007 has been authorized, and the EWA Operating Principles have been extended to December 31, 2007. The State and federal agencies that are signatories to the CALFED Multi Species Conservation Strategy (“Conservation Agreement”) have also agreed to extend these regulatory commitments to December 31, 2007 to support protection and recovery of the covered species.

• Environmental Water Account – Work will continue on determining if and how a long-term Environmental Water Account (EWA) could be established beyond the short-term EWA set up for the CALFED Stage 1 period. DWR, USBR, USFWS, NOAA Fisheries, and DFG are the lead agencies working to develop a long-term EWA which will protect Delta fisheries while pro viding water supply reliability benefits to SWP and CVP exporters.

• Delta Regional Ecosystem Restoration Implementation Plan – The Delta Regional Ecosystem Restoration Implementation Plan (DRERIP) is a long-term regional planning effort under the CALFED ERP to help examine the Program’s actions, targets, and milestones for the Delta. The DRERIP process includes agency review and public input, and will be the primary forum for revising ERP targets. DRERIP is currently being prepared by the Department of Fish and Game in cooperation with the Bay-Delta Authority, USFWS, NOAA Fisheries, other CALFED agencies, academic institutions, science advisors,1912 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005

and stakeholder scientists. Through DRERIP, the ERP

expects to refine and prioritize actions, evaluate the scientific foundation for actions and milestones, and use adaptive management feedback. The Bay-Delta Public Advisory Committee’s Ecosystem Subcommittee provides public input for DRERIP activities, and additional oppor- tunities for future public participation in the Program will continue in the future.

• Focused Study on South Delta Hydrodynamics and Fish

– As a science-related action, DWR, USBR, USGS,DFG and USFWS will study fish movement, distribution, and entrainment in the south Delta to better understand the impacts of the Delta export pumps and barrier operations.

• South Delta Fish Facilities – The fish facilities for both the SWP and CVP will be evaluated by USBR and DWR, and recommendations for modifying operations to better manage changing environmental conditions will be developed. Alternative facilities and intake locations will be included as options, and special consideration will be made for future SWP pumping operations.
Delta Region Farmland Preservation and Private Lands Stewardship Program The DPC has partnered with the American Farmland Trust to
prepare an inventory of Delta agriculture resources and their economic value. This inventory will help identify and preserve the best farmland in the DPC jurisdiction and the five Delta counties, while developing “wildlife friendly” practices on as much of the agricultural land as possible. The resulting DPCplan could help in the implementation of the CALFED ecosystem restoration goal of protecting and enhancing 45,000- 75,000 acres of wildlife friendly agriculture in the Delta.
Other CALFED ERP Projects While DRERIP represents ERP’s focus for long-term regional

e cosystem restoration planning, there are many other activities that the Program intends to carry forward into the future. The CALFED Programmatic EIS/EIR identified six strategic goals for the 30-year planning horizon of the Bay-Delta Program, which include issues such as endangered species recovery, invasive species, ecological processes, harvested species, habitats, and water and sediment quality. The CALFED ERP has developed multiple objectives for each of these goals, which include developing strategies for high priority topics, conducting a long-term program of milestone assessment for ecosystem-related CALFED programs, and identification offunding allocations to support a unified CALFED-wide restoration and recover y process. 

### Levee System IntegrityThe future of levee management in the Delta is currently evolving, and several recent developments may play a role in future levee implementation activities. Key issues that will have a strong influence on future levee work can be grouped into three main categories: oversight, funding, and ecosystem integration.
Oversight In recent history, levee maintenance and construction in the Delta ha s primarily been the responsibility of reclamation districts and, to a lesser extent, the U.S. Army Corps of Engineers. In the extreme northern part of the Delta near Sacramento, the Sacramento Flood Control Agency (SAFCA) was created in 1989 to manage levies in the Sacramento region as a joint powers agency, and it now has management responsibili

ties in the Delta as well. The Department of Water Resources has provided financing, planning, engineering, research andmonitoring capabilities to assist local groups (reclamation districts), and the California Department of Fish and Game and Bay-Delta Authority have also played important management and oversight roles.

In the future, the form and magnitude of responsibility shouldered by the participating levee agencies could be modified. Recently proposed State legislation (AB 1983) could increase the responsibilities of the Reclamation Board, which monitors reclamation districts and collects their tax revenues. The CALFED Record of Decision (ROD) envisioned a larger federal role through the Army Corps in levee maintenance and improvements than has yet materialized, and the Corps has been discussing ways to play a greater role with other participating agencies. A recent court decision regarding the liability of the State in the event of levee failures is another driving force that could lead DWR and other agencies to reexamine how levee responsibilities and oversight are assigned within the Delta.
Funding As already mentioned, the CALFED ROD recommended greater levels of federal participation, including financial participation, than has actually occurred. The majority of funding for Delta levees work over the last decade has come from State and local sources, with only a small amount of federal contributions. The federal government has historically identified flood protection as a national goal eligible for federal financing, and Delta interests could attempt to obtain more Congressional appropriations forfuture levee projects. Congress approved recent CALFED Legislation to authorize additional federal funds for levee programs, but very little of those funds have actually been appropriated by the federal budget process.California Water Plan Update 2005

**Volume 3** Regional Reports 2012 Following the CALFED principle of “beneficiary pays”, the sources for levee funding could also be modified to draw more contributions from those receiving benefits from Delta levees. Because of the location of the Delta levees and the important rolethey play in protecting the drinking water supply for the majority of Californians, some have argued that a greater portion of levee costs should be assigned to consumers of Delta waterexports. The Bay-Delta Authority is currently conducting studies to attempt to quantify ranges of benefits associated with all CALFED Program Elements, including the Levee System Integrity Program. Potential alternative revenue sources identified by a draft Bay-Delta Authority “Finance Options” report include recreational boating fees and a state-administered water user fee assessed on CVP and SWP water users, with the possible inclusion of non-project water users as well.

Ecosystem IntegrationThe degree in which levee programs include ecosystem restoration activities could also be changed in the future. The same legislation that would increase the role of the Reclamation Board in levee improvement work (AB 1983) would also allow the Board to directly finance habitat restoration work, instead of having to partner with other state agencies as is currently required. While the legislation could potentially streamline required restoration work and allow levee maintenance and enlargement to move forward more quickly, it can also be argued that ecosystem responsibilities should be limited to agencies such as the Department of Fish and Game so that Reclamation Districts can focus on preventing and fighting floods. Delta levee initiatives in the future will have to consider what level ecosystem management should be involved in levee efforts, and what groups and agencies should participate in ecosystem activities.

T he North Delta Flood Control and Ecosystem Restoration Project is an example of how the Department of Water Resources is addressing levee and ecosystem restoration issues in the North Delta. Also known as the North Delta ImprovementsProject (NDIP), the Project is considering several “wildlifefriendly” modifications to levees in the North Delta, including setback levees. A draft EIR/EIS for the Project is currently being developed, and alternatives have already been identified that include a number of levee-related initiatives.



### Recreation Recreation-related activities in the Delta will continue to be important in the future, and several new initiatives are being planned to better characterize current recreational resources while developing a vision for future Delta recreation activities. One major effort is the Delta Recreation Master Plan. In 2003, DPC received funding for preparation of phase one of the Delta Recreation Master Plan, which has now been completed and addresses water-based recreation needs The second phase of this plan will evaluate land-based recreation needs in the Delta, as soon as funding for the study is secured. The Master Plan intends to draw from existing Delta recreation studies and documents, use public outreach and stakeholder involvement,and include new GIS mapping technologies to produce a Deltawide recreation plan.


### Other Activities Many other potential actions that could be taken by the California Bay-Delta Authority and others in the upstream Sacramento River and San Joaquin River hydrologic regions can benefit the Delta, especially with respect to water quality and flood flows. These actions may include improvements for conveyance, storage, levee stability, water quality, water useefficiency, and watersheds. A few of these additional initiatives are listed here.

• **WUE Agricultural and Urban Water Use Measurement**

- One of the Bay-Delta Program’s Water Use Efficiency projects being developed throughout California is the Agricultural and Urban Water Use Measurement initiative.This program to produce consistent, complete, and compatible water measurement practices statewide is critical for monitoring and managing diversions and instream flows within Delta, and in other parts of the state as well. Considerable stakeholder input has been obtained for the WUE measurement efforts, and assistance from the State legislature will also be required for the project to be fully implemented.

• **Lower Sacramento River Regional Flood Control Project**

- The Sacramento Area Flood Control Agency (SAFCA) is currently considering a project to expand the Yolo Bypass and use the Sacramento Deep Water Channel to convey floodwaters for the protection of urban areas. This project could potentially be integrated with CALFED activities, which have to date included studies on the modification of the Yolo Bypass to enhance fisheries, easement acquisitions, and modeling efforts led by the California Reclamation Board. Local governments, particularly the City of Rio Vista, would need to be included in planning and implementation to address downstream flooding concerns.2112 **Chapter 12** Sacramento-San Joaquin Delta Region California Water Plan Update 2005

The above projects will provide incremental improvements in water supply, water quality, levees, and ecosystem, but will not totally achieve the desired goals for the Delta in themselves. Toachieve the desired cumulative benefits, integration and linkage of these projects is essential. Coordination of the CALFEDProgram, its implementing agencies, local and regional stakeholders, and the Delta Protection Commission with adequate funding will help the region to continue to serve society’s demand for farm products, fishing, recreation, and water—all while protecting the Delta’s ecosystem and water quality.


## Selected References

• 2002 California 305(b) Report on Water Quality, State

W ater Resources Control Board.

• 2003 Annual Report, California Bay-Delta Authority.

• Bay-Delta Authority Website calwater.ca.gov/

• California’s Groundwater. Bulletin 118 03 (Draft), Update

2003, Califor nia Department of Water Resources.

• Delta Atlas, California Department of Water Resources,

July 1995.

• Delta Primer, a field guide to the California Delta, Jane

W

olff, William Stout Publishers, San Francisco, 2003.

• Delta Protection Commission Web site www.delta.

ca.gov/

• DRAFT California Bay Delta Program Ecosystem Restoration Program & Drinking Water Quality Program: Water Quality Issues, California Bay-Delta Authority, Draft July 2003.

• DRAFT Finance Options Report, California Bay-Delta

Authority , Draft May 2004.

• DRAFT Memorandum of Understanding Regarding

C ALFED Bay Delta Program Activities in the Delta (Including Attachment A: Summary of Status of Activities Under Consideration), California Bay-Delta Authority, Draft May 21, 2004.

• Layperson’s Guide to the Delta, Water Education Foundation, 2000.

• Nonpoint Source Program Strategy and Implementation

Plan, 1998-2013, State Water Resources Control Board, California Coastal Commission, January 2000.

• Strategic Plan, State Water Resources Control Board,

Regional Water Quality Control Boards, November 15, 2001.

• Water Quality Control Plan, Regional Water Quality

Control Board.

• Watershed Management Initiative Chapter, Regional

W ater Quality Control Board.i 13 **Chapter 13** Mountain Counties Area California Water Plan Update 2005 

# Chapter 13 Mountain Counties Area

Contents Chapter 13 Mountain Counties Area ......................................................................................................................13-1 Setting .............................. 13-1 Climate ............................. 13-1 Population ........................ 13-1 Land Use .......................... 13-1 Water Supply and Use ....... 13-1 State of the Region ............ 13-5 Challenges ................... 13-5 Accomplishments .......... 13-6 Relationship to Other Regions .............................................................................................................................13-7 Looking to the Future ......... 13-7 Regional Planning ............. 13-7 Water Portfolios for Water Years 1998, 2000, and 2001 .....................................................................................13-8 Selected References ......... 13-10



## Boxes Box 13-1 Regulation of Ditch Water .......................................................................................................................13-2 Box 13-2 1997 Flood Damage to Canals ................................................................................................................13-5 Box 13-3 1996 Sierra Nevada Ecosystem Study ......................................................................................................13-6 Box 13-4 South Sutter W ater District’s Canal Improvement Plan ................................................................................13-8



## Figures Figure 13-1 Mountain Counties area (map) .............................................................................................................13-ii Figure 13-2 Mountain Counties water balance for water years 1998, 2000, 2001 (2 bar charts) ...............................13-3 Figure 13-3 Mountain Counties - illustrated water flow diagram .............................................................................13-15 Figure 13-4 Mountain Counties - schematic flow diagram ......................................................................................13-16



## Tables Table 13-1 Mountain Counties water balance summary ...........................................................................................13-9 T able 13-2 Mountain Counties water use and distribution of dedicated supplies .......................................................13-11 T able 13-3 Mountain Counties water portfolios ......................................................................................................13-14**Volume 3** Regional Reports California Water Plan Update 2005



### LASSEN

PLUMAS

BUTTE SIERRA

NEVADA

PLACER YUBA

EL DORADO

ALPINE

TUOLUMNE CALAVERAS AMADOR

MARIPOSA

MADERA

FRESNO Flow in TAF 1998 3,116 2000 4,611 2001 2,411 **Lake Oroville**

Flow in TAF 1998 4,191 2000 2,619 2001 1,357 **Folsom Lake**

Flow in TAF 1998 1,268 2000 741 2001 380 **Camanche Reservoir Mokelumne Aqueduct**  Flow in TAF 1998

10 2000 9 2001 7 **Nor th Lahontan Region**  **Little Truckee**

Flow in TAF 1998

0 2000 1 2001 2 **Nor th Lahontan Region** 

**Echo Lake Conduit**

Flow in TAF 1998 764 2000 1,212 2001 735 **Millerton Lake Friant-Kern Canal (CVP)**  Flow in TAF 1998 5,429 2000 3,181 2001 1,598 **New Melones Reservoir New Don Pedro Lake**  **Hetch Hetchy Aqueduct**

Flow in TAF 1998 2,215 2000 1,184 2001 895 **Hensley Lake Eastman Lake**  **Mariposa Reservoir Owens Reservoir** 

**Bear Reservoir Lake McClure**  **Figure13-1 Mountain Counties Area**

The Mountain Counties area includes the foothills and mountains on the western slopes of the Sierra Nevada, extending from Lassen County on the north to Fresno County on the south. Arrows indicate annual flows entering and leaving the region for water years 1998, 2000, and 2001. **Some Statistics** Area -15,758 square miles (9.9% of State) Average annual precipitation - 42.7 inches Year 2000 population - 541,710 2030 population projection - 840,025 Total reservoir storage capacity -18,185 TAF 2000 irrigated crop area - 93,600 acres .

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. **Some Statistics** Area -15,758 square miles (9.9% of State) Average annual precipitation - 42.7 inches Year 2000 population - 541,710 2030 population projection - 840,025 Total reservoir storage capacity -18,185 TAF 2000 irrigated crop area - 93,600 acres .

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.1 13 **Chapter 13** Mountain Counties Area California Water Plan Update 2005



# Chapter 13 Mountain Counties Area

the same five-year period was about 7 percent. Although total population in the area is low, the area’s rate of growth is projected to continue to out pace that of the state as a whole. The projected population increase between 2000 and 2030 is about 55 percent for this foothill and mountain area, while the state’s growth is projected at about 41 percent.



## Land Use
The economies of these mountain and foothill areas have historically been tied to the land. Tourism, ranching, timber h arvesting, limited mining, and agriculture, primarily in thelower elevations, continue as an economic base for many comm unities. A limiting factor for the area’s population growth is the relatively small amount of land in private ownership. The federal government is the dominant landowner in the area, with most of the higher elevation lands being under the management of the U.S. Forest Service or National Park Service.
Much of the state’s developed water supply originates inthis upland area, including several CVP and SWP reserv oirs. Although the region has abundant surface water supplies, most of it is unavailable locally because of prior water rights appropriations for downstream or out-of-basin users. Local use of water originating within this region is less than 3 percent of the total statewide consumption.


## Water Supply and Use Locally developed surface water supplies account for almost 70 percent of the public consumptive water supply for this region. Water is either diverted directly from the area’s streams and lakes or from local storage reservoirs and conveyance facilities.
Many of the residents in the unincorporated areas are dependent on small, independent municipal water systems, and afew areas still use untreated water diverted directly from rawwater ditch delivery systems (see Box 13-1). In addition, many 

## Setting The Mountain Counties Area of California includes the foothills and mountains of the western slope of the Sierra Nevada and a portion of the Cascade Range. The area extends from the southern tip of Lassen County to the northern part of Fresno County (Figure 13-1) and covers the eastern portions of the Sacramento River and San Joaquin River hydrologic regions. The foothill and mountain areas of these two hydrologic regions are grouped together for the purpose of presenting their common characteristics. The area generally includes all or portions of Shasta, Lassen, Plumas, Butte, Sierra, Yuba, Nevada, Placer, El Dorado, Amador, Alpine, Calaveras, Tuolumne, Mariposa, Madera, and Fresno counties. Elevations vary from around 100 feet near the edge of the valley floor to more than 10,000 feet at locations along the Sierra Nevada and Cascade Range crest line. The major rivers in the area include the Feather, Yuba, Bear, Rubicon, and American rivers in the Sacramento River region; and the Cosumnes, Moke

lumne, Calaveras, Stanislaus, Tuolumne, Merced, Chowchilla, Fresno, and San Joaquin rivers in the San Joaquin River region.



## Climate The climate is closely tied to the topography and varies widely throughout the area; mean annual precipitation ranges from more than 80 inches at Strawberry Valley, east of Lake Oroville, to less than 12 inches at Fresno County. Much of the precipitationfalls as snow in the higher elevations in the winter. Water managers throughout the area rely on this natural storage as snow in the winter months and capture or divert spring snowmelt runoff.


## Population The 2000 population of the area was about 541,710, less than 2 percent of the state’s total population. However, the effects of urbanization are beginning to affect some of the foothill areas. Population growth in the area from 1990 to 1995 was almost 10 percent. The state’s growth rate duringCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 2 13 individual water users throughout the area have developed their own supplies, typically groundwater for domestic use and small surface storage or in limited cases, groundwater foragricultural use. Figure 13-2 provides a graphical presentation of all of the water supply sources that are used to meet the developed water uses within this hydrologic subarea for 1998, 2000, and 2001. M ining operations, especially hydraulic mining, from the Gold Rush Era marked the beginning of much of the water supply development to the foothill and mountain areas. Many of those early mining water systems were later taken over by other water users. Pacific Gas & Electric Co. and other hydropower utilities subsequently developed an extensive hydroelectricpower and consumptive water use delivery system through

## Box 13-1 Regulation of Ditch Water
Regulation of Ditch Water – Water users in the foothills who obtain their water from ditches are no longer able to use that water for domestic purposes. New rules promulgated by the California Department of Health Services and the U.S. Environmental Protection Agency prohibit residential customers from cooking, drinking or brushing teeth with ditch water, including water processed by home treatment systems. In order to meet these requirements, several water districts are requiring customers to receive 5 gallons of bottled drinking water per month. This quantity meets the state’s minimum estimate of what a normal household would use in a month. The Mountain Counties Area had less than 2 percent of the state’s total population in the 2000 Census. However, the effects of urbanization are beginning to affect some of the foothills like those east of Sacramento. (DWR photo)3 13 **Chapter 13** Mountain Counties Area California Water Plan Update 2005

**Dedicated Water Supplies Figure 13-2 Mountain Counties water balance for water years 1998, 2000, 2001** 

0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000

1998 2000 2001Thousand Acre-Feet Wild & Scenic R.

Instream Flow
Irrigated Agriculture

Urban

0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000

1998 2000 2001Thousand Acre-Feet Reuse & Recycle
Ground Water

Federal Projects Local Projects **Applied Water Uses**

Three years show a marked change in the amount and relative pro portions of water delivered to Mountain Counties region urban and agricultural sectors and water dedicated to the environment ( applied water, top chart), where the water came from, and how much water was reused among sectors (dedicated water supplies, bottom chart).California Water Plan Update 2005

**Volume 3** Regional Reports 4 13 out the Sierra Nevada, often incorporating some of the old mining ditches. Most of the early water conveyance facilities were later transferred to local water agencies for consumptive water deliveries. Some of these water agencies still use the ditch systems as a primary means of water delivery to both their water treatment plants and to the individual water users along the route to the treatment plants. Many of these old and unimproved conveyance systems, including ditches, flumes, and pipes have been in use for more than 100 years.

While logging and mining operations have decreased, recreation and tourism have increased in the Mountain Counties region which produces different effects on water use and quality. Second homes and vacation rentals are a growing trend in many of the foothill and mountain areas. This typeof residential usage means that, although there is no permanent population associated with these homes, water use can be high on most weekends during the popular summer and winter vacation periods. For example, Groveland Community Services District, near Yosemite National Park in southern Tuolumne County, estimates that the service area population more than doubles during peak vacation periods. Tourism water use, which is most significant in the central Sierra, tends to inflate the area’s per capita water use because the volume of water consumed is greater than the permanent residential population would indicate.
Most of the area’s irrigated acres are found in the foothills and mountains of the Sacramento River Region. The dominant crop is pasture, which constitutes about 70 percent of thetotal irrigated acreage. Other crops with significant acreage include alfalfa, grain, wine grapes, apples and other deciduous fruit, and olives. Projections indicate almost no change in future irrigated acreage, with a slight change in crop mix. Significant amounts of unirrigated lands are also used as rangeland for livestock.
Environmental water use in the region consists of instream flow requirements and Wild and Scenic River designations. Instream flow requirements within the area are found on the Stanislaus River, below Goodwin Dam, and the TuolumneRiver, below La Grange Dam. The controlling instream minimum flow requirements for the remainder of the area’s major rivers are located on the valley floor, which is downstream and outside of the Mountain Counties region. In addition, there are many smaller reservoirs in the area that do have instream flow requirements, which are met by the project operators. However, only the largest instream flow requirements for the major rivers have been counted as the instream demands for this water use tabulation. Documented Wild and Scenic River designations in this region include portions of the Feather River (north fork), Yuba River, American River, Tuolumne River andMerced River. Figure 13-2 presents a bar chart that summarizes all of the dedicated and developed urban, agricultural, and environmental water uses within the Mountain Counties region for 1998, 2000, and 2001.

G roundwater constitutes less than 10 percent of region’s water supply and is generally used as a supply for single family homes. Groundwater availability is often limited to fractured rock and small alluvial deposits immediately adjacent to the area’s many streams. In the rural areas, many individual residences are wholly dependent upon groundwater for domestic use. In addition, many homes are not connected to a municipal water system and are typically dependent upon individual wells, which are often unreliable during drought periods. A limited number of farmers have developed wells with enough production to irrigate their lands in all but the driest of years. In general, groundwater is an inadequate and unreliable supply for large scale usage in this region, due to the limitations of the fractured granite formations that constitute much of the Sierra Nevada foothills and the western slopes of the mountains.

In addition to locally supplied surface water, some water isprovided by storage facilities of the federal Central Valley Project, other federal water facilities, locally developed imports, and reclaimed wastewater. In the American River basin, the Foresthill Public Utility District has a water supply contract for CVP water. Calaveras County Water District and Union Public Utility District receive water from New Hogan Reservoir, which is operated by the U.S. Army Corps of Engineers. Irrigated pasture in Sierra County receives a small amount of water imported from the Little Truckee River in the North Lahontan Hydrologic Region. In addition, PG&E imports water from Echo Lake near Lake Tahoe in the North Lahontan Hydrologic Region as part of a hydropower diversion into the American River basin. Reclaimed wastewater is used to a limited extentto irrigate golf courses and meet other landscaping and agricultural needs throughout the region.

The water use and water supply graphs in Figure 13-2 summarize the detailed regional water accounting contained inthe water portfolio tables at the end of this regional description. As shown on the map in Figure 13-1, most of the area’s surface water either flows to or is diverted to other regions outside of the Mountain Counties area.5 13 **Chapter 13** Mountain Counties Area California Water Plan Update 2005



## State of the Region Challenges By virtue of their location in the upstream watersheds, domestic water users in the Mountain Counties generally benefit from higher quality surface water than most other areas of the state. Many water supplies originate from pristine foothill or mountain sources, which are largely unaffected by agricultural or urban pollution. Unfortunately, this higher quality surface water is often degraded as it flows downstream or is diverted through the numerous canals and delivery systems (see Box 13-2). Water drainage from abandoned mines, including Penn Mine in the Mokelumne River watershed, contributes metals and other water quality problems downstream. Mercury was imported into this region as part of the gold mining activities of past eras, and it remains in some water supplies as a water quality issue. Erosion from natural flooding, logging and land development, and areas devastated from forest fires, introduces sedimentation and nutrients to waterways, as well as causing elevated stream temperatures due to the reduction of riparianshade canopy. This is a concern to both domestic water treatment operations and to spawning and migration of salmonids, particularly below the major dams on the Stanislaus, Tuolumne, and Merced rivers. The conversion of agricultural land to residential use, and undeveloped land to both agricultural and residential use, could present new and different water quality problems in the future.

The biggest water issue facing users in the area is the need to improve the water supply reliability of the various water delivery systems throughout the area. The population of some areas is increasing rapidly because people are migrating to the foothills from the metropolitan areas. Despite rapid population growth, the customer base for many of the water districts is still relatively small and widely dispersed. This smaller base, coupled with previous development of the less costly reservoir sites, as wellas the mountainous topography, makes water system improvements expensive and makes interconnections between systems impractical. Also, a limited array of options are available to meet current and projected needs, due to the local water users’ limited ability to pay the costs of improvements and the lack of groundwater aquifers to facilitate groundwater banking and conjunctive use strategies. Some local officials directly responsible for water delivery within the Mountain Counties Area are evaluating the potential use of California’s “Area of Origin and Watershed Protection” water laws as a method for meeting projected growth within their respective areas as well as improving water supply reliability to existing users. These legal statutes provide for the reservation of water supplies for counties in which the water originates when a state water right filing is assigned for use elsewhere, as well as setting aside water for future development in the area. Typically, however, the upland areas have not had the population and financial base to contract with SWP or CVP for a water supply, nor has the SWP or CVP had adequate supplies of unallocated water to meet the needs of most Mountain Counties communities.

H istorically many small water systems in the foothills and mountains of California have relied on surface water or local springs with minimal or no water treatment. Some small rural water systems have also relied upon water from open ditch systems,sometimes in use for over 100 years, that were intended primarily for agriculture or hydropower purposes and used onlyincidentally for domestic water. However, with a greater recognition of the health risk posed by pathogens in drinking water sources, these systems must now maintain reliable filtration and disinfection facilities and in most cases required improvements are being made. In addition, low housing densities in this region result in a large number of isolated, small water systems, which individually do not have the technical or financial capacity to upgrade their treatment facilities and infrastructure, and cannot consolidate to take financial advantage of a larger water utility customer base. When such treatment upgrades are infeasible, water purveyors are instead requiring customers to use bottled water for drinking purposes.

A nother common problem for the older open ditch delivery systems within the Mountain Counties region is the tendency to have significant conveyance seepages and evaporation, as well as sanitary hazards associated with open water systems. Repairs and replacement of some open ditch systems have sometimes been opposed by various groups and landowners who argue



## Box 13-2 1997 Flood Damage to Canals
After the 1997 floods, a landslide destroyed a 30-foot section of Georgetown’s canal, which supplies water to 9,000 customers in six towns in rural El Dorado County. Nearby, El Dorado Irrigation District also lost use of it flume from the forebay on the American River due to a separate landslide.California Water Plan Update 2005

**Volume 3** Regional Reports 6 13 against the reduction of the aesthetics of the flowing canal, and of vegetation and wildlife sustained by leakage and percolation. Many other water users in this region are on private wells, which are unregulated statewide and, thus, have never been assessed for potential water quality contamination.

M ost areas within the Mountain Counties region are very concerned with forest fires and the damage they cause to the watersheds and the wooden infrastructure associated with the ditch systems. Every year, numerous forest fires occur in the Sierra Nevada which expose the watersheds to soil erosion. Sediment loads from erosion can obstruct water flow in openditches, reduce reservoir capacity, add nutrient loading, diminish water quality and cause excessive algae growth. Fires have damaged components of the ditch systems including diversion structures and flume sections. As a result some small communities have been left without water for extended periods of time.

W

ater supply managers in the area are concerned about federal and State designations of Wild and Scenic streams (see Box 13- 3). When a river or stream is designated as Wild and Scenic, the accompanying regulations can sometimes preclude water resources development. Environmental interests are concerned about preserving the few undeveloped streams or sections of streams remaining in the area. Federal statutes prohibit federal agencies from constructing, authorizing, or funding water resources projects that would have a direct and adverse effect on the values for which the river was designated. The state wild andscenic law prohibits construction of any dam, reservoir, divers ion, or other water impoundment in specific regions. However in some situations where a diversion is needed to supply domestic water to residents of an area through which the wild and scenic river flows, such diversions may sometimes be authorized. Like surface water, groundwater in this region is generally ofgood quality, but it may be contaminated by naturally occurring radon, uranium, or sulfide mineral deposits containingheavy metals. In particular, radon contamination is associated with granite, such as the granite batholith of the Sierra Nevada. Meeting State secondary standards for both iron and magnesium can also be difficult for some groundwater sources. Also, because of the lack of community wastewater systems, individual septic tanks are prevalent for rural residential development in this region. The failure of septic tank systems can create sewage flows that have the potential to adversely affecting nearby wells and groundwater quality. 

### AccomplishmentsIn 1997, Sacramento area interests released the Draft Recomm endations for the Water Forum Agreement. This group is pursuing two objectives: (1) provide a reliable water supply for the region through 2030 and (2) reserve the fishery, wildlife recreation, and aesthetic values of the Lower American River. The proposed draft solution includes an integrated package of seven actions. Generally, foothill water interests would increase their diversions from the American River in average and wet years and decrease those diversions in drier and driest years. Placer County Water Agency would be providing excess water from non-American River sources to many of the participating water agencies during drier water years to help make up the decreased American River diversions in those years. PCWA’s participation in many of these specific agreements is dependent upon State Water Resources Control Board approval for changes to conditions of its existing water rights.



## Box 13-3 1996 Sierra Nevada Ecosystem Study
In 1996, the University of California released its “Sierra Nevada Ecosystem Study,” as a part of a project by the samename. The report is the result of a three year congressionally mandated study of the entire Sierra Nevada, with a primar y emphasis on gathering and analyzing data to assist Congress and other decision-makers in future management of the mountain range. The project goal is to maintain the health and sustainability of the ecosystem while providing resources to meet human needs. The study states that, “excluding the hard-to-quantify public good value of flood control and reservoir-based recreation, the hydroelectric generating, irrigation and urban use values of water are far greater than the combined value of all other commodities produced in the Sierra Nevada.” The report estimates the value of water at 60 percent of all commodities produced in the foothills and mountains of the Sierra Nevada. This commodity-based view of water leads to some of the study’s related conclusions that, “increased concern about the ecological impacts of diversions as well as the social decisions about who should bear the financial burdens of plans to reduce, or at least stop the growth of, these impacts requires a greater understanding of how diversions, economic benefits, and ecological impacts are linked.”7 13 **Chapter 13** Mountain Counties Area California Water Plan Update 2005



## Relationship to Other Regions Much of the state’s developed water supply originates from the Sierra Nevada in the upland portions of this region. Many surface storage and diversion facilities capture and export water, including several CVP and SWP reservoirs, and local facilities operated by Yuba County Water Agency, East Bay Municipal Utility District, the city of San Francisco, Modesto and Turlock Irrigation districts, and Merced Irrigation District. The map in Figure 13-1 provides information about the volume of water exports from the Mountain Counties region for years 1998, 2000 and 2001. 

## Looking to the Future Urban and agricultural water users in most of the Mountain Counties region have limited water supply options to meet future needs, because of the mountainous topography, lack of significant groundwater aquifers, limited financial resourcesfor water development, and the fact that most water originating in the area was previously allocated to downstream users and exports through the water rights process. However, most water agencies are actively pursuing a wide variety of supply augmentation and demand reduction actions to secure water for future needs. For example, El Dorado Irrigation District is considering feasibility studies for development of a 31,000acre-feet Alder Reservoir, which would provide drought stora ge, enhanced environmental flows, and hydropower generat ion benefits. In addition to its ongoing water conservation and water recycling programs, the district is planning on lining a 2.5-mile ditch system to save an estimated 1,300 acre-feet that is currently lost through seepage.

At the southern end of the Mountain Counties region in the Upper San Joaquin River basin, the California Bay-Delta Authority is conducting feasibility studies for development of additional surface storage in the upper watershed. Severalalternative sites will be evaluated including one called Temperance Flat. If it is determined to be feasible, such storage could help to contribute to restoration and improvement of water flows and quality in the lower San Joaquin River, and would facilitate conjunctive water management and water exchanges among downstream water agencies.

T hroughout California there are more than 100 existing hydroelectric projects that hold Federal Energy Regulatory Commission (FERC) licenses which will be up for federal license renewal within the next ten years. A large number of these projects are located on river systems within the Mountain Counties region. As part of the FERC license renewal process, the project owners must conduct studies to evaluate the future use, impacts and alternatives for each hydroelectric project.For local water agencies this process will provide key opport unities to develop and improve integrated resource planning, so that the proposed reoperation and federal re-licensing of hydroelectric projects can also consider improved benefits to local water supplies, instream flows, and recreation uses. 

## Regional Planning The Mountain Counties Water Resources Association assists water agencies and local governments in coordinating water resource matters important to the region. The association also interfaces with applicable state officials and departments on water resource matters. Some agencies are looking for new supplies from expansion of existing storage, re-operation ofexisting hydroelectric storage, or construction of new storage. For example, Lyons Reservoir, in the Tuolumne Utilities District is a 5,800 acre-foot joint use facility, supplying both hydroelectric power and consumptive water storage. TUD is considering the expansion of Lyons Reservoir to 50,000 acre-feet. While large quantities of groundwater are not generally available in the Sierra-Cascade Mountain Area, a number of local agencies are implementing groundwater management strategies to help ensure the reliability of local groundwater supplies.

Some counties and water districts meet regularly to discuss regional water issues. One example is the Mokelumne River Forum. The Forum consists of thirteen entities that have an interest in the Mokelumne Watershed and have signed an MOU to have DWR facilitate regional collaboration to help resolve the complex water supply issues.

S everal local agencies and governments are developing recycled water projects. A few examples are:

• El Dorado Irrigation District is investigating construction

o f up to 5,000 acre-feet of seasonal storage to more efficiently use recycled water in the district. The storage would allow for meeting recycled water demands, without supplemental water or shortages through 2025.

• The city of Auburn is developing a proposal to sell up to

5,000 acre-feet of recycled water to agricultural users by 2020. The water is expected to be delivered near Lincoln, on the valley floor. This option is included in the Sacramento River Region management plan.

• The city of Angels Camp in Calaveras County is developi ng plans to expand its reclaimed water deliveries by 300 acre-feet to agricultural, environmental, and landscape users by 2020.California Water Plan Update 2005

**Volume 3** Regional Reports 8 13

• Two other projects in Calaveras County will deliver 470

acre-feet for landscape irrigation.

• Groveland Community Services District, in southern

T

uolumne County anticipates 425 acre-feet being made available to agricultural customers by 2020.

• The Sierra Conservation Center in Tuolumne County is

planning a project to deliver almost 300 acre-feet for agriculture and landscape irrigation by 2020.

Urban growth, with an average of 1,800 new homes eachyear in the city of Lincoln, has created a need for new drinking water in an area that has been served agricultural water since 1926. An association consisting of the Nevada Irrigation District, Placer County Water Agency, and the city of Lincoln, is investigating how to accommodate this change in water use in order to eliminate the need to find additional water supplies or to continue groundwater pumping to meet the domestic water needs.
In February 2000, South Sutter Water District, Camp Far West Irrigation District, and the California Department of Water Resources entered an agreement to meet the State Water Resource Control Board’s water quality objectives -- Phase 8 ofthe Water Quality Control Plan for the San Francisco/Sacramento-San Joaquin Delta Estuary. In exchange for up to 4,400 acre-feet of water from Camp Far West Reservoir in each dry and critical year, DWR agreed to assume all responsibility for all Bear River water rights holders’ obligations under Phase 8. Inaddition, South Sutter Water District is implementing its Conveya nce Canal Improvement Plan to increase the system conveyance capacity (see Box 13-4). The additional water for conveyance will be obtained from increases in diversion of stored water and water that is spilled from Camp Far West Reservoir. 

## Water Portfolios for Water **Y ears 1998, 2000, and 2001**  The following tables and graphs present actual information about the water supplies and uses for the Mountain Counties hydrologic region. Water year 1998 was a wet year for this region, with annual precipitation at 154 percent of normal, while the statewide annual precipitation was 171 percent of average. Year 2000 represents nearly normal hydrologicconditions with annual precipitation at 107 percent of average for the Mountain Counties region, and 2001 reflected dryer water year conditions with annual precipitation at 65 percent of average. For comparison, statewide average precipitation in year 2001 was 72 percent of normal. Table 13-1 provides more detailed information about the total water supplies available to this region for these three specific yearsfrom precipitation, imports and groundwater, and also summarizes the uses of all of the water supplies.

A more detailed tabulation of the portion of the total available water that is dedicated to urban, agricultural and environmental purposes is presented in Table 13-2. Table 13-3 also provides detailed information about the sources of the developed water supplies, which are primarily from surface water systems and include a large percentage of water imports from other regions. These developed water use and supplies for the three years are also presented graphically in Figures 13-2. The three Water Portfolio tables included in Table 13-3 and companion Water Portfolio flow diagrams (Figures 13-3 and 13-4) provided more detailed information about how the available water supplies are distributed and used throughout this region.



## Box 13-4 South Sutter Water District’s Canal Improvement Plan

• Increase the flexibility , timing, and reliability of surface water supplies.

• Replenish groundwater supplies for extraction in drier years.

• Recharge the groundwater basin to reduce the ef fect of declining groundwater levels.

• Provide the ability to meet additional water needs (including Bay Delta Authority environmental objectives) outside of SSWD.

• Replace older conveyance structures with advanced control technology.

• Enhance SSWD’ s conjunctive water management activities.

• Reduce the need for cropping changes during drier water years.

• Increase power generation and decrease power use for pumping.

• Increase water use efficiency by installing state-of-the-ar t water control and measurement structures.9 13 **Chapter 13** Mountain Counties Area California Water Plan Update 2005

**Water Entering the Region** Precipitation 55,206 38,412 23,445 Inflow from Oregon/Mexico 0 0 0 Inflow from Colorado River 0 0 0 Impor ts from Other Regions 10 10 9 **Total 55,216 38,422 23,454 Water Leaving the Region**  Consumptive Use of Applied Water * 237 279 264 (Ag, M&I, Wetlands) Outflow to Oregon/Nevada/Mexico 0 0 0 Expor ts to Other Regions 19,983 13,548 7,376 Statutory Required Outflow to Salt Sink 1,227 1,090 654 Additional Outflow to Salt Sink 81 174 180 Evaporation, Evapotranspiration of Native Vegetation, Groundwater Subsurface Outflows, 31,274 24,153 17,781 Natural and Incidental Runoff, Ag Effective Precipitation & Other Outflows **Total 52,802 39,244 26,255 Storage Changes in the Region**  [+] Water added to storage [-] Water removed from storage Change in Surface Reservoir Storage 2,420 -802 -2,721 Change in Groundwater Storage ** -6 -20 -80 **Total 2,414 -822 -2,801**
**Applied Water *** (compare with Consumptive Use) 402 472 452

*Footnote for applied water Consumptive use is the amount of applied water used and no lon ger available as a source of supply. Applied water is greater than consumptive use because it includes consumptive use, reuse, and outflows.

**Footnote for change in Groundwater Storage

C hange in Groundwater Storage is based upon best available information. Basins in the north part of the state (North Coast, San Francisco, Sacramento River and North Lahontan regions and parts of Central Coast and San Joaquin River regions) have been modeled – spring 1997 to spring 1998 for the 1998 water year and spring 1999 to spring 2000 for the 2000 water year. All other regions and year 2001 were calculated using the following equation:
GW change in storage = intentional recharge + deep percolation of applied water + conveyance deep percolation - withdrawals
This equation does not include the unknown factors such as nat ural recharge and subsurface inflow and outflow. Water Year (Percent of Normal Precipitation) 1998 (154%) 2000 (107%) 2001 (65%) **Table 13-1 Mountain Counties Water Balance Summary - TAF**  Water Entering the Region – Water Leaving the Region = Storage Changes in RegionCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 10 13 

## Selected References

• 2002 California 305(b) Report on Water Quality, State

W ater Resources Control Board

• California’s Groundwater Bulletin 118-03, Update 2003,

Califor nia Department of Water Resources

• Nonpoint Source Program Strategy and Implementation

Plan, 1998-2013, State Water Resources Control Board, California Coastal Commission, January 2000

• Strategic Plan, State Water Resources Control Board,

Regional Water Quality Control Boards, November 15, 2001

• Water Needs Assessment, Mountain Counties Water

Resources Association, March 1999.

• Water Quality Control Plan, Regional Water Quality

Control Board

• Watershed Management Initiative Chapter, Regional

W ater Quality Control Board11 13 **Chapter 13** Mountain Counties Area California Water Plan Update 2005

Applied Net Depletion Applied Net Depletion Applied Net Depletion Water Use Water Use Water Use Water Use Water Use Water Use 2001 1998 2000

**WATER USE**

**DEDICATED WATER SUPPLIES Table 13-2**  **Mountain Counties of California Water Use and Distribution of Dedicated Supplies (TAF)**

**Urban** Large Landscape 11.2 11.0 11.4 Commercial 11.8 12.1 12.2 Industrial 14.6 14.6 14.8 Energy Production 0.0 0.0 0.0 Residential - Interior 40.4 40.3 41.4 Residential - Exterior 63.6 63.5 66.1 Evapotranspiration of Applied Water 59.7 59.7 55.4 55.4 57.1 57.1 E&ET and Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Outflow 59.2 59.2 64.6 64.6 66.8 66.8 Conveyance Applied Water 19.9 15.7 18.9 Conveyance Evaporation & ETAW 10.1 10.1 8.1 8.1 9.7 9.7 Conveyance Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Outflow 9.8 9.8 7.6 7.6 9.2 9.2 GW Recharge Applied Water 0.0 0.0 0.0 GW Recharge Evap + Evapotranspiration 0.0 0.0 0.0 0.0 0.0 0.0 **Total Urban Use 161.5 138.8 138.8 157.2 135.7 135.7 164.8 142.8 142.8**  **Agriculture** On-Farm Applied Water 260.2 330.6 306.5 Evapotranspiration of Applied Water 177.1 177.1 223.9 223.9 206.5 206.5 E&ET and Deep Perc to Salt Sink 6.0 6.0 7.8 7.8 6.0 6.0 Outflow 63.4 8.4 80.8 80.8 82.6 82.6 Conveyance Applied Water 49.1 59.6 58.1 Conveyance Evaporation & ETAW 10.6 10.6 22.8 22.8 22.7 22.7 Conveyance Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Outflow 26.3 3.7 21.3 21.3 21.5 21.5 GW Recharge Applied Water 0.0 0.0 0.0 GW Recharge Evap + Evapotranspiration 0.0 0.0 0.0 0.0 0.0 0.0 **Total Agricultural Use 309.3 283.4 205.8 390.2 356.6 356.6 364.6 339.3 339.3**  **Environmental** Instream Applied Water 1,569.5 1,563.0 1,450.6 Outflow 313.0 313.0 326.5 326.5 340.9 340.9 Wild & Scenic Applied Water 6,381.6 4,098.7 1,968.8 Outflow 914.1 914.1 763.0 763.0 313.3 313.3 Required Delta Outflow Applied Water 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Managed Wetlands Habitat Applied Water 0.0 0.0 0.0 Evapotranspiration of Applied Water 0.0 0.0 0.0 0.0 0.0 0.0 E&ET and Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Applied Water 0.0 0.0 0.0 Conveyance Evaporation & ETAW 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Deep Perc to Salt Sink 0.0 0.0 0.0 0.0 0.0 0.0 Conveyance Outflow 0.0 0.0 0.0 0.0 0.0 0.0 Total Managed Wetlands Use 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 **Total Environmental Use 7,951.1 1,227.1 1,227.1 5,661.7 1,089.5 1,089.5 3,419.4 654.2 654.2**  **TOTAL USE AND OUTFLOW 8,421.9 1,649.3 1,571.7 6,209.1 1,581.8 1,581.8 3,948.8 1,136.3 1,136.3**

**Surface Water** Local Deliveries 1,582.1 1,582.1 1,506.3 1,514.9 1,514.9 1,514.9 1,064.4 1,064.4 1,064.4 Local Imported Deliveries 9.7 9.7 9.2 10.4 10.4 10.4 8.5 8.5 8.5 Colorado River Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 CVP Base and Project Deliveries 25.7 25.7 24.5 26.3 26.3 26.3 18.4 18.4 18.4 Other Federal Deliveries 1.6 1.6 1.5 1.1 1.1 1.1 1.6 1.6 1.6 SWP Deliveries 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Required Environmental Instream Flow 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Groundwater Net Withdrawal 29.0 29.0 29.0 27.9 27.9 27.9 42.2 42.2 42.2 Deep Percolation of Surface and GW 37.3 38.4 36.7 Reuse/Recycle Reuse Surface Water 6,735.3 4,588.9 2,775.8 Recycled Water 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 **TOTAL SUPPLIES 8,421.9 1,649.3 1,571.7 6,209.1 1,581.8 1,581.8 3,948.8 1,136.3 1,136.3**  **Balance = Use - Supplies 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0** 13 13 **Chapter 13** Mountain Counties Area California Water Plan Update 2005



# Water Portfolios

Mountain Counties AreaCalifornia Water Plan Update 2005

**Volume 3** Regional Reports 14 13 **Table 13-3 Mountain Counties water portfolios (TAF)** 

ID Mountain Counties Mountain Counties Mountain Counties Number: Flow Diagram Component (see legend) 1998 2000 2001 1 Colorado River Deliveries

- - - 2 Total Desalination

- - - 3 Water from Refineries

- - - 4a Inflow From Oregon

- - - b Inflow From Mexico

- - - 5 Precipitation 55,205.7 38,412.2 23,444.5 6a Runoff - Natural N/A N/A N/A b Runoff - Incidental N/A N/A N/A 7 Total Groundwater Natural Recharge N/A N/A N/A 8 Groundwater Subsurface Inflow 9 Local Deliveries 1,582.1 1,514.9 1,064.4 10 Local Imports 9.7 10.4 8.5 11a Central Valley Project :: Base Deliveries

- - - b Central Valley Project :: Project Deliveries 25.7 26.3 18.4 12 Other Federal Deliveries 1.6 1.1 1.6 13 State Water Project Deliveries

- - - 14a Water Transfers - Regional

- - - b Water Transfers - Imported

- - - 15a Releases for Delta Outflow - CVP b Releases for Delta Outflow - SWP c Instream Flow Applied Water 1,569.5 1,563.0 1,450.6 16 Environmental Water Account Releases

- - - 17a Conveyance Return Flows to Developed Supply - Urban

- - - b Conveyance Return Flows to Developed Supply - Ag 22.6

- - c Conveyance Return Flows to Developed Supply - Managed Wetlands

- - - 18a Conveyance Seepage - Urban

- - - b Conveyance Seepage - Ag 3.6 4.7 3.7 c Conveyance Seepage - Managed Wetlands

- - - 19a Recycled Water - Agriculture 1.2 1.2 1.2 b Recycled Water - Urban

- - - c Recycled Water - Groundwater

- - - 20a Return Flow to Developed Supply - Ag 55.0

- - b Return Flow to Developed Supply - Wetlands

- - - c Return Flow to Developed Supply - Urban

- - - 21a Deep Percolation of Applied Water - Ag 6.0 6.1 4.5 b Deep Percolation of Applied Water - Wetlands

- - - c Deep Percolation of Applied Water - Urban 22.7 21.5 22.0 22a Reuse of Return Flows within Region - Ag 7.7 12.0 6.9 b Reuse of Return Flows within Region - Wetlands, Instream, W&S 6,724.0 4,572.2 2,765.2 24a Return Flow for Delta Outflow - Ag

- - - b Return Flow for Delta Outflow - Wetlands, Instream, W&S 1,227.1 1,089.5 654.2 c Return Flow for Delta Outflow - Urban Wastewater

- - - 25 Direct Diversions N/A N/A N/A 26 Surface Water in Storage - Beg of Yr 11,595.4 12,504.6 11,702.6 27 Groundwater Extractions - Banked

- - - 28 Groundwater Extractions - Adjudicated

- - - 29 Groundwater Extractions - Unadjudicated 66.3 66.3 78.9 23 Groundwater Subsurface Outflow

- - - 30 Surface Water Storage - End of Yr 14,015.1 11,702.6 8,982.1 31 Groundwater Recharge-Contract Banking

- - - 32 Groundwater Recharge-Adjudicated Basins

- - - 33 Groundwater Recharge-Unadjudicated Basins

- - - 34a Evaporation and Evapotranspiration from Native Vegetation N/A N/A N/A b Evaporation and Evapotranspiration from Unirrigated Ag N/A N/A N/A 35a Evaporation from Lakes 92.4 92.4 92.4 b Evaporation from Reservoirs 630.2 630.2 630.2 36 Ag Effective Precipitation on Irrigated Lands 82.3 57.8 77 37 Agricultural Water Use 260.2 330.6 306.5 38 Managed Wetlands Water Use

- - - 39a Urban Residential Use - Single Family - Interior 29.1 28.8 29.7 b Urban Residential Use - Single Family - Exterior 59.3 58.8 61.4 c Urban Residential Use - Multi-family - Interior 11.3 11.5 11.7 d Urban Residential Use - Multi-family - Exterior 4.3 4.7 4.7 40 Urban Commercial Use 11.8 12.1 12.2 41 Urban Industrial Use 14.6 14.6 14.8 42 Urban Large Landscape 11.2 11.0 11.4 43 Urban Energy Production

- - - 44 Instream Flow 313 326.5 340.9 45 Required Delta Outflow

- - - 46 Wild and Scenic Rivers 914.1 763 313.3 47a Evapotranspiration of Applied Water - Ag 177.1 223.9 206.5 b Evapotranspiration of Applied Water - Managed Wetlands

- - - c Evapotranspiration of Applied Water - Urban 59.7 55.4 57.1 48 Evaporation and Evapotranspiration from Urban Wastewater

- - - 49 Return Flows Evaporation and Evapotranspiration - Ag 6 7.8 6 50 Urban Waste Water Produced 45.6 53.2 54.9 51a Conveyance Evaporation and Evapotranspiration - Urban 10.1 8.1 9.7 b Conveyance Evaporation and Evapotranspiration - Ag 10.6 22.8 22.7 c Conveyance Evaporation and Evapotranspiration - Managed Wetlands

- - - d Conveyance Outflow to Mexico

- 0 0 52a Return Flows to Salt Sink - Ag 12.1 102.1 104.1 b Return Flows to Salt Sink - Urban 69 72.2 76 c Return Flows to Salt Sink - Wetlands 0 0 0 53 Remaining Natural Runoff - Flows to Salt Sink 0 0 0 54a Outflow to Nevada

- - - b Outflow to Oregon

- - - c Outflow to Mexico

- - - 55 Regional Imports 49.7 39.8 31.9 56 Regional Exports 2153.1 2476.7 1561.2 59 Groundwater Net Change in Storage -5.5 -20.1 -79.5 60 Surface Water Net Change in Storage 2,419.7 -802.0 -2,720.5 61 Surface Water Total Available Storage 18,185.0 18,185.0 18,185.0
Inflows Outflows Green number signifies included in summary boxes**Chapter 13** Mountain Counties Area 1 5 13 **Volume 3**  Regional Reports California Wa ter Plan Update 200 51 6 13 **Volume 3**  Regional Reports **Chapter 13** Mountain Counties Area California Wa ter Plan Update 200 51G **Glossary** California Water Plan Update 2005 

# Glossary

**A** acre-foot (af) – The volume of water that would cover one acre to a depth of one foot; equal to 43,560 cubic feet or 325,851 gallons. 

### adjudication – The act of judging or deciding by law. In the context of an adjudicated groundwater basin, landowners or other parties have turned to the courts to settle disputes over how much groundwater can be extracted by each party to the decision. 

### agricultural discharge standards – State and federal water quality regulations regarding discharge of water used for agricultural production to streams, rivers, groundwater aquifers, or evaporation ponds. Context: Scenario Factor

. 

### agricultural lands stewardship – Conserving natural resources and protecting the environment by compensating owners of private farms and ranches for implementing stewardship practices. Context: Resource Management Strategy. 

### agriculture water reliability (average) – A measure of a water system’s ability to sustain the social, environmental, and economic agricultural systems that it serves during a year of average precipitation 

### agricultural water use efficiency – The ratio of applied water to the amount of water required to sustain agricultural productivity. Efficiency is increased through the application of less water to achieve the same beneficial productivity or by achieving more productivity while applying the same amount of water. Context: Scenario Factor, Resource Management Strategy. 

### allocation of long-term contractual imports – Interregional allocation of water for periods of time more than one year through mechanisms such as the State and federal water projects. Context: Scenario Factor

. 

### alluvial – Of or pertaining to or composed of alluvium.



### alluvium – A general term for clay, silt, sand, gravel, or similar unconsolidated detrital material, deposited during comparatively recent geologic time by a stream or other body of running water, as a sorted or semi-sorted sediment in the bed of the stream or on its fl oodplain or delta, as a cone or fan at the base of a mountain slope. 

### anthropogenic – Of human origin or resulting from human activity. 

### applied water – The amount of water from any source needed to meet the demand for beneficial use by the user. It includes consumptive use, reuse, and outflows. 

### applied water reduction – A decrease in the amount of water needed to meet the demand for beneficial use; can be a supply for both new (real) water and reused water. Context: Resource Management Strategy. See also new water. 

### appropriative right – The right to use water that is diverted or extracted by a nonriparian or nonoverlying party for nonriparian or nonoverlying beneficial uses. In California, surface water appropriative rights are subject to a statutory permitting process while groundwater appropriation is not. 

### aquifer – A body of rock or sediment that is sufficiently porous and permeable to store, transmit, and yield significant (i.e. economic) quantities of groundwater to wells and springs. 

### aquifer remediation – See groundwater remediation/aquifer remediation 

### aquitard – A confining bed or formation composed of rock or sediment that retards but does not prevent the flow of water to or from an adjacent aquifer. It does not readily yield water to wells or springs, but stores groundwater.California Water Plan Update 2005

2G 

### artesian aquifer – A body of rock or sediment containing groundwater that is under greater than hydrostatic pressure; that is, a confined aquifer. When an artesian aquifer is penetrated by a well, the water level will rise above the top of the aquifer.


### artesian pressure – Hydrostatic pressure of artesian water, often expressed in terms of pounds per square inch; or the height, in feet above the land surface, of a column of water that would be supported by the pressure. 

### artificial recharge – The (intentional) addition of water to a groundwater reservoir by human activity, such as putting surface water into dug or constructed spreading basins or injecting water through wells. 

### available groundwater storage capacity – The volume of a groundwater basin that is unsaturated and capable of storing groundwater.



### available soil water – The amount of water held in the soil that can be extracted by a crop; often expressed in inches per foot of soil depth. It is the amount of water released between in situ fi eld capacity and the permanent wilting point. 

### average annual cost of implementing option – Annualized total monetary cost of option required for “turn key” implementation including environmental and third party impact mitigation, storage, conveyance, energy, capitalized operations and maintenance, administrative, planning, legal and engineering costs. Context: Evaluation Criteria; Planning Concept/Consideration. 

### average annual runoff – The average value of total annual runoff volume calculated for a selected period of record, at a specified location, such as a dam or stream gage. 

### average year water demand – Demand for water under average hydrologic conditions for a specific level of development.



## B basin irrigation – Irrigation by flooding areas of level land surrounded by dikes. Used interchangeably with level border irrigation, but usually refers to smaller areas. 

### basin management objectives (BMOs) – See management objectives


### beneficial use – Use of water either directly by people or for their overall benefit. There are 24 categories of beneficial uses identified by the State Water Resources Control Board. 

### border irrigation – Irrigation by flooding strips of land, rectangular in shape and cross leveled, bordered by dikes. Water is applied at a rate sufficient to move it down the strip in a uniform sheet. Border strips having no downfield slope are referred to as level border systems. Border systems constructed on terraced lands are commonly referred to as benched borders.



## C catastrophic vulnerability – The probability and magnitude of potential negative economic, public health, and environmental impacts associated with water management actions. Context: Scenario Factor , Evaluation Criteria.. 

### Central Valley Project deliveries – The volume of water imported to a given area through the Central Valley Project. Context: Scenario Factor. 

### check irrigation – Modification of a border strip with small earth ridges or restrictions (checks) constructed or inserted at intervals to retain water as it flows down the strip.3G **Glossary** California Water Plan Update 2005



### CIMIS – California Irrigation Management Information System- A network of automated weather stations that are owned and operated cooperatively between the DWR and local agencies. The stations are installed in most of the agricultural and urban areas in the State and provide farm and large landscape irrigation managers and researchers with “real-time” weather data to estimate crop and landscape ET rates and make irrigation management decisions. 

### climate change – Changes in average annual temperature and precipitation and their monthly patterns in 2050 compared to today. 

### Colorado River supply – The volume of water California has the right to import from the Colorado River. California’s allocation is 4.4 million acre-feet per year plus 50% of any declared surplus. Context: Scenario Factor

. 

### commercial activity mix – The mix of high- and low-water using commercial activity. Note that commercial activity is broken into two factors: total commercial activity and commercial activity mix. The latter factor allows designation of the type of commercial activity that is occurring. See also total commercial activity . Context: Scenario Factor.


### community water system – A public water system that serves at least 15 service connections used by yearlong residents or regularly serves at least 25 yearlong residents. See also public water system.


### consumed fraction – the portion of agricultural applied irrigation water that satisfies evapotranspiration.



### conveyance – Provides for the movement of water and includes the use of natural and constructed facilities including open channels, pipelines, diversions, fi sh screens distribution systems and pump lifts. 

### conveyance facilities – Canals, pipelines, pump lifts, ditches, etc. used to move water from one area to another. Context: Study Plan Building Block, Resource Management Strategy. 

### confined aquifer – An aquifer that is bounded above and below by formations of distinctly lower permeability than that of the aquifer itself. An aquifer containing confined groundwater. See also artesian aquifer. 

### conjunctive management and groundwater storage – Coordinated operation of surface water storage and use, ground water storage and use, and conveyance facilities. Context: Resource Management Strategy

. 

### conjunctive use – Application of surface and groundwater to meet the demand for a beneficial use. Coordinated and planned management of both surface and groundwater resources in order to maximize the efficient use of the resource; that is, the planned and managed operation of a groundwater basin and a surface water storage system combined through a coordinated conveyance infrastructure. Water is stored in the groundwater basin for later and planned use by intentionally recharging the basin during years of above-average surface water supply. 

### conservation tillage – A tillage practice that leaves plant residues on the soil surface for erosion control and moisture conservation


### consumptive use – A quantity of applied water that is not available for immediate or economical reuse. It includes water that evaporates, transpires, or is incorporated into products, plant tissue, or animal tissue. Consumptively used water is removed from available supplies without return to a water resource system (uses such as manufacturing, agriculture, landscaping, food preparation, and in the case of Colorado River water, water that is not returned to the river.)



### contaminant – Any substance or property preventing the use or reducing the usability of the water for ordinary purposes such as drinking, preparing food, bathing washing, recreation, and cooling. Any solute or cause of change in physical properties that renders water unfi t for a given use. (Generally considered synonymous with pollutant.)California Water Plan Update 2005

4G 

### cost recovery – Designates who (marginal or existing users) pays the marginal and existing water costs. Also specifies cir cumstances where other revenue sources are used to recover costs. Costs can include capital, O&M, financing, environmental compliance (documentation, permitting and mitigation), etc. Context: Scenario Factor 

### cost of reliability enhancement – The total cost required to add an increment of reliability. Context: Evaluation Criteria. 

### cost of unreliability – The sum of the forgone long-term value and short-term costs incurred to the users. Context: Evaluation Criteria



### critical conditions of overdraft – A groundwater basin in which continuation of present practices would probably result in significant adverse overdraft-related environmental, social, or economic impacts. The definition was created after an extensive public input process during the development of the Bulletin 118-80 repor t.



### cover crop – Close growing crop, that provides soil protection, seeding protection, and soil improvement between periods of normal crop production, or between trees in orchards and vines in vineyards. When plowed under and incorporated into the soil, cover crops may be referred to as green manure crops. 

### crop coefficient – A numerical factor (normally identified as Kp or Kc) that relates the evapotranspiration (ET) of the individual crop (ETc) to reference evaporation or some other index. 

### crop idling – The temporary or permanent fallowing of land previously under irrigation that results in a reduction in stresses to a water system (e.g., alternate land use must result in a reduction in water use and/or enhancement of water quality, etc.). Context: Scenario Factor.


### crop rotation – A system of farming in which a succession of different crops are planted on the same land area, as opposed to growing the same crop time after time (monoculture).


### crop unit water use – The volume of irrigation water used per unit area of land, commonly expressed in acre feet per acre. As used in scenario evaluation, a change in unit water use can be a function of evapotranspiration rates and cultural practices, but NOT use efficiency. Agricultural use efficiency is captured under its own distinct factor. Context: Scenario Factor.



## D deep percolation – Percolation of water through the ground and beyond the lower limit of the root zone of plants into groundwater 

### deep percolation of surface and groundwater – Water that is applied for agricultural, urban, and managed wetlands in excess of the net use requirements. Water either is applied for groundwater recharge or percolates naturally to the water table. This does not include reuse, evaporation, evapotranspiration of applied water, or flows/percolation to a salt sink. Context: Water Portfolio 

### depletion – Water consumed through evapotranspiration, flows to salt sinks or is otherwise no longer available as a source supply.



### desalination – Water treatment process for the removal of salt from water for beneficial use. Source water can be brackish (low salinity) or seawater. Context: Study Plan Building Block. 

### dewvaporation (Atmospheric Pressure Desalination) – Desalination through humidification and subsequent dehumidification (collection of evaporated water). Context: Resource Management strategy

. 

### distribution system – System of ditches or conduits and their controls that conveys water from the supply canal to the farm points of delivery5G **Glossary** California Water Plan Update 2005



### domestic well – A water well used to supply water for the domestic needs of an individual residence or systems of four or fewer service connections. 

### drinking water standards – State and federal regulations regarding water delivered by water purveyors that is used as a potable supply. Context: Scenario Factor. 

### drinking water system – see public water system 

### drinking water treatment and distribution – Treatment is the physical, biological and chemical processes that make water suitable for potable use. Distribution includes storage, pumping, and pipe systems to protect and deliver the treated water to customers. Context: Study Plan Building Block. 

### drip irrigation – A method of micro irrigation wherein water is applied to the soil surface as drops or small streams through emitters. Discharge rates are generally less than 8 L/h (2 gal/h) for a single-outlet emitters and 12 L/h (3 gal/h) per meter for line-source emitters. 

### drought preparedness– The magnitude and probability of economic, social or environmental consequences that would occur as a result of a sustained drought under a given study plan. Evaluation criteria measure the “drought tolerance” of study plans. Context: Water Management Objective 

### drought condition – Hydrologic conditions during a defined period, greater than one dry year, when precipitation and runoff are much less than average. 

### drought year supply – The average annual supply of a water development system during a defi ned drought period. 

### duty of water – The total volume of irrigation water required to mature a particular type of crop. It includes consumptive use, evaporation, and seepage as well as the water returned to streams by percolation and surface water.



## E earthquake vulnerability – see seismic vulnerability



### economic incentives – Financial assistance and pricing policies intended to influence water management including, for example, amount of use, time of use wastewater volume, and source of supply . Context: Resource Management Strategy.


### ecosystem restoration – The activity of improving the condition of natural landscapes and biotic communities. Context: Study Plan Building Block. 

### effective precipitation – That portion of precipitation that supplies crop evapotranspiration. It includes precipitation stored in the soil before and during the growing season 

### effective porosity – The volume of voids or open spaces in alluvium and rocks that is interconnected and can transmit fluids. 

### effective rooting depth – The depth from which soil moisture is extracted; it is determined by the crop rooting characteristics and soil depth limitations. 

### electrical conductivity (EC) – The measure of the ability of water to conduct an electrical current, the magnitude of which depends on the dissolved mineral content of the water.California Water Plan Update 2005

6G 

### energy availability – The energy consumption to facilitate water management-related actions such as desalting, pump-storage, groundwater extraction, conveyance or treatment. This criterion pertains to the economic feasibility of a proposed water management action in terms of O&M costs. Context: Evaluation Criteria.



### energy costs – Refers to the cost of energy use related to producing, conveying and applying water. It also refers to the cost of energy use for processes and inputs not directly related to water, but which can affect the demand for water (e.g., the cost of nitrogen fertilizer, tractor manufacturing, etc.). Context: Scenario Factor. 

### energy production – Both instantaneous capacity (megawatt) and energy produced (kilowatt hours). Context: Evaluation Criteria. 

### environmental justice – The fair treatment of people of all races, cultures, and incomes with respect to the development, adoption, implementation, and enforcement of environmental laws, regulations, and policies. (Section 65040.12. (c) Government code) 

### environmental water (flow based) – The amount of water dedicated to instream fishery uses, Wild and Scenic rivers, BayDelta outflow and aquatic habitat.


### environmental water (land based) – The amount of water used for fresh-water managed wetlands and native vegetation. 

### environmental water quality – Water quality in terms of ecosystem health, recreation, salinity intrusion, usability per sector, treatment costs, etc. Aquatic species and water bodies are vulnerable to changes to water quality

. 

### ETo (Reference Evapotranspiration) – The evapotranspiration rate from an extended surface of 3 to 6 inch (8–15 cm) tall green grass cover of uniform height, actively growing, completely shading the ground, and not short on water (the reference ET reported by CIMIS).



### evaluation criteria – The technical information that will be used to compare the favorability of different response packages of resource management strategies against future scenarios in California Water Plan Update 2010. They are designed to identify and measure potential effects on water supply, the environment, energy use or production, recreational opportunities, groundwater overdraft, and many more.


### evaporation – The physical process by which a liquid or solid is transformed to a gaseous state. 

### evaporative demand – The collective infl uence of all climatic factors on the rate of evaporation of water

. 

### evapotranspiration (ET) – The quantity of water transpired by plants, retained in plant tissues, and evaporated from plant tissues and surrounding soil surfaces 

### evapotranspiration of applied water (ETAW) – The portion of ET satisfied by applied irrigation water.



## F flood irrigation – Method of irrigation where water is applied to the soil surface without flow controls, such as furrows, borders, or corrugations 

### floodplain management – Actions designed to reduce risks to life, property, and the environment due to flooding. Actions can include watershed management, infrastructure construction and operation, variations in land use practices, floodway designations, etc. Context: Study Plan Building Block.7G **Glossary** California Water Plan Update 2005



### flood risk – The magnitude and probability of consequences that would occur as a result of flood-induced infrastructure damage under a given study plan. Context: Evaluation Criteria. 

### flow diagram – Diagram that characterizes a region’s hydrologic cycle by documenting sources of water such as precipitation and inflows and tracks the water as it flows (through many different uses) to its ultimate destinations. 

### flow diagram table – An itemized listing of all the categories contained in the Flow Diagram including more detailed information, organized by “inputs” and “withdrawals.”


### full cost – (1) all monetary costs associated with project planning, implementation, financing, or impact mitigation plus any recurring costs required to sustain benefits; PLUS (2) all nonmonetary costs that are incurred either at implementation or on a recurring basis such as unmitigable environmental or cultural impacts, public trust, environmental justice, or other nonmarket-based societal values. (Coincides with CEQA/NEPA study and other permitting requirements.) Context: Planning Concept/Consideration. 

### furrow irrigation – Method of surface irrigation where the water is supplied to small ditches or furrows for guiding across the field.



## G groundwater – Water that occurs beneath the land surface and fills the pore spaces of the alluvium, soil, or rock formation in which it is situated. It excludes soil moisture, which refers to water held by capillary action in the upper unsaturated zones of soil or rock. 

### groundwater basin – An alluvial aquifer or a stacked series of alluvial aquifers with reasonably well-defined boundaries in a lateral direction and having a definable bottom. 

### groundwater budget – A numerical accounting, the groundwater equation, of the recharge, discharge and changes in storage of an aquifer, part of an aquifer, or a system of aquifers. 

### groundwater in storage – The quantity of water in the zone of saturation. 

### groundwater management – The planned and coordinated management of a groundwater basin or portion of a groundwater basin with a goal of long-term sustainability of the resource. 

### groundwater management plan – A comprehensive written document developed for the purpose of groundwater management and adopted by an agency having appropriate legal or statutory authority. 

### groundwater mining – The process, deliberate or inadvertent, of extracting groundwater from a source at a rate in excess of the replenishment rate such that the groundwater level declines persistently, threatening exhaustion of the supply or at least a decline of pumping levels to uneconomic depths. 

### groundwater monitoring network – A series of monitoring wells at appropriate locations and depths to effectively cover the area of interest. Scale and density of monitoring wells is dependent on the size and complexity of the area of interest, and the objective of monitoring. 

### groundwater overdraft – The condition of a groundwater basin in which the amount of water withdrawn by pumping exceeds the amount of water that recharges the basin over a period of years during which water supply conditions approximate average conditions.California Water Plan Update 2005

8G 

### groundwater quality – See water quality 

### groundwater recharge facility – A structure that serves to conduct surface water into the ground for the purpose of replenishing groundwater. The facility may consist of dug or constructed spreading basins, pits, ditches, furrows, streambed modifications, or injection wells. 

### groundwater recharge – The natural or intentional infiltration of surface water into the zone of saturation. 

### groundwater remediation/aquifer remediation – Groundwater Remediation involves extracting contaminated groundwater from an aquifer, treating it, and then either putting it back in the aquifer or using it for agricultural or municipal purposes. Aquifer Remediation is usually accomplished by treating groundwater while it is still in the aquifer, using in-situ methods involving biological, physical, or chemical treatment or electrokinetics. Context: Study Plan Building Block, Resource Management Strategy. 

### groundwater source area – An area where groundwater may be found in economically retrievable quantities outside of normally defined groundwater basins, generally referring to areas of fractured bedrock in foothill and mountainous terrain where groundwater development is based on successful well penetration through interconnecting fracture systems. Well yields are generally lower in fractured bedrock than wells within groundwater basins. 

### groundwater storage capacity – Volume of void space that can be occupied by water in a given volume of a formation, aquifer, or groundwater basin. 

### groundwater subbasin – A subdivision of a groundwater basin created by dividing the basin using geologic and hydrologic conditions or institutional boundaries. 

### groundwater table – The upper surface of the zone of saturation in an unconfined aquifer. 

### groundwater quality – Water quality can affect supply integrity. Many pollutants are hydrophilic and not easily filtered by soil. Treated groundwater can be added to water supply. Context: Evaluation Criteria.



## H hazardous waste – Waste that poses a present or potential danger to human beings or other organisms because it is toxic, flammable, radioactive, explosive, or has some other property that produces substantial risk to life. 

### hydraulic barrier – A barrier created by injecting fresh water to control seawater intrusion in an aquifer, or created by water injection to control migration of contaminants in an aquifer. 

### hydraulic conductivity – A measure of the capacity for a rock or soil to transmit water; generally has the units of feet/day or cm/sec. 

### hydrograph – A graph that shows some property of groundwater or surface water as a function of time at a given point. 

### hydrology – A science related to the occurrence and distribution of natural water on the earth including the annual volume and the monthly timing of runoff. 

### hydrologic cycle – The circulation of water from the ocean through the atmosphere to the land and ultimately back to the ocean.9G **Glossary** California Water Plan Update 2005



### hydrologic region – A study area consisting of multiple planning subareas. California is divided into 10 hydrologic regions. 

### hydrostratigraphy – A geologic framework consisting of a body of rock having considerable lateral extent and composing a reasonably distinct hydrologic system. 

### hyporheic zone – The region of saturated sediments beneath and beside the active channel and that contain some proportion of surface water that was part of the flow in the surface channel and went back underground and can mix with groundwater.



## I in-lieu recharge – The practice of providing surplus surface water to historic groundwater users, thereby leaving groundwater in storage for later use. 

### industrial activity mix – The mix of high and low water using industrial activity. Note that Industrial Activity is broken into two factors: Total Industrial Activity and Industrial Activity Mix. The latter factor allows designation of the type of industry that is occurring. This is necessary to account for the large variation in water demands by industry type. See also total industrial activity. Context: Scenario Factor.


### infiltration – The flow of water downward from the land surface into and through the upper soil layers. 

### infiltration capacity – The maximum rate at which infiltration can occur under specifi c conditions of soil moisture.


### infrastructure – the underlying foundation or basic framework of a system 

### integrated regional water management – A comprehensive, systems approach for determining the appropriate mix of demand and supply management options that provide long-term, reliable water supply at lowest reasonable cost and with highest possible benefi ts to customers, economic development, environmental quality, and other social objectives.


### intercropping – The simultaneous planting of two or more crops in the same field. The practice is used to help control pest populations that can occur on monoculture crops, sometimes called “polycropping” or “plant stratifi cation.” 

### interregional import projects – Movement of water between regions through mechanisms such as the State and federal water projects. Context: Scenario Factor.


### irrecoverable water – the amount of applied water that is not available for supply or reuse, including discharge to saline sinks, evaporation, and evapotranspiration. See recoverable water 

### irrigation efficiency (IE) – The efficiency of water application and use, calculated by dividing a portion of applied water that is beneficially used by the total applied water, expressed as a percentage The two main beneficial uses are crop water use (evapotranspiration, ETc) and leaching to maintain a salt balance.


### irrigation water requirements – The quantity of water exclusive of precipitation that is required from various uses.



## J joint powers agreement (JPA) – An agreement entered into by two or more public agencies that allows them to jointly exercise any power common to the contracting parties. The JPA is defined in Ch. 5 (commencing with Section 6500) of Division 7 of Title 1 of the California Government Code.California Water Plan Update 2005

10G 

## L land subsidence – The lowering of the natural land surface due to groundwater (or oil and gas) extraction. 

### leaching requirements – The fraction of water entering the soil that must pass through the root zone in order to prevent soil salinity from exceeding a specific value. 

### leaching efficiency – The ratio of the average salt concentration in drainage water to an average salt concentration in the soil water of the root zone when near field capacity. 

### leaky confining layer – A low-permeability layer that can transmit water at sufficient rates to furnish some recharge from an adjacent aquifer to a well. 

### lithologic log – A record of the lithology of the soils, sediments and/or rock encountered in a borehole from the surface to the bottom. 

### lithology – The description of rocks, especially in hand specimen and in outcrop, on the basis of such characteristics as color, mineralogic composition, and grain size.



## M management objectives – Objectives that set forth the priorities and measurable criteria of water management. Examples include improve water quality, augment water supplies, improve use efficiency, etc. 

### matching water quality to use – a resource management strategy that recognizes not all water uses require the same quality water. High quality water sources can be used for drinking and industrial purposes that benefit from higher quality water, and lesser quality water can be desirable for some uses, such as riparian streams with plant materials benefiting fish. Context: Resource Management Strategy. 

### maximum contaminant level (MCL) – The highest drinking water contaminant concentration allowed under federal and State Safe Drinking Water Act regulations.


### microirrigation – The frequent application of small quantities of water as drops, tiny streams, or miniature spray through emitters or applicators placed along a water delivery line. Microirrigation encompasses a number of methods or concepts such as bubbler, drip, trickle, mist, or spray. 

### multicropping – The practice of consecutively producing two crops (double cropping) or more of either like or unlike com modities on the same land within the same year. An example of double cropping might be to harvest a wheat crop by early summer and then plant corn or beans on that acreage for harvest in the fall. Suitable climates and reliable water supplies are important factors with this practice.



## N naturally occurring conservation – The amount of background conservation occurring independent of the BMP and EWMP programs (e.g., plumbing codes, etc.). Context: Scenario Factor. 

### natural recharge – Natural replenishment of an aquifer generally from snowmelt and runoff; through seepage from the surface. 

### net groundwater withdrawal - groundwater extraction in excess of percolation into a groundwater basin. Context: Water Portfolio11G **Glossary** California Water Plan Update 2005



### net water use (demand) – the amount of water needed in a water service area to meet all requirements or demands. It is the sum of several components including evapotranspiration of applied water in an area, the irrecoverable water from the distribution system, and the outflow leaving the service area; does not include reuse of water within a service area.



### new water – Water that is legally and empirically available for a beneficial use; can be developed through many strategies such as capturing surplus water, desalination of ocean water and reductions in depletions. (Same meaning as real water) Context: Planning Concept/Consideration.


### nonpoint source – Pollution discharged over a wide land area, not from one specific location. These are forms of diffuse pollution caused by sediment, nutrients, etc., carried to lakes and streams by sur face runoff. See also point source



## O operational flexibility – The temporal or spatial operational efficiency of existing and proposed infrastructure to maximize benefits. Context: Evaluation Criteria. 

### operational yield – An optimal amount of groundwater that should be withdrawn from an aquifer system or a groundwater basin each year. It is a dynamic quantity that must be determined from a set of alternative groundwater management decisions subject to goals, objectives, and constraints of the management plan.



### ordinance – A law set forth by a governmental authority. 

### other interregional import deliveries – This factor is intended to capture the interregional movement of water for “projects” such as Russian River, Trinity River Exports or Putah South Canal. Note that the project name must be specified in the study plan narrative. Context: Scenario Factor.


### overdraft – See groundwater overdraft 

### overlying right – Property owners above a common aquifer possess a mutual right to the reasonable and beneficial use of a groundwater resource on land overlying the aquifer from which the water is taken. Overlying rights are correlative (related to each other) and overlying users of a common water source must share the resource on a pro rata basis in times of shortage. A proper overlying use takes precedence over all non-overlying uses.



## P pelagic fish – fish that spawn in open water, often near the surface. Many river-dwelling anadromous fishes, such as shad are also pelagic spawners 

### perched groundwater – Groundwater supported by a zone of material of low permeability located above an underlying main body of groundwater. 

### percolation – Process in which water moves through a porous material, usually surface water migrating through soil toward a groundwater aquifer. 

### perennial yield – The maximum quantity of water that can be annually withdrawn from a groundwater basin over a long period of time (during which water supply conditions approximate average conditions) without developing an overdraft condition. 

### permeability – The capability of soil or other geologic formations to transmit water.California Water Plan Update 2005

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### pesticide – Any of a class of chemicals used for killing insects, weeds, or other undesirable entities. Most commonly associated with agricultural activities, but has signifi cant domestic use in California.


### point source – A specific site from which wastewater or polluted water is discharged into a water body. See also nonpoint source 

### pollution (of water) – The alteration of the physical, chemical, or biological properties of water by the introduction of any substance into water that adversely affects any beneficial use of water. 

### pollution prevention – Improving water quality for all beneficial uses by protecting water at its source, reducing the need and cost for other water management actions and treatment. Context: Resource Management Strategy

. 

### population density – The average number of people per square mile for a planning area. Context: Scenario Factor

. 

### population distribution – The geographic location within California of the population projection. Context: Scenario Factor. 

### population projection – The 2030 forecast of population made by the California Department of Finance or other agencies. Context: Scenario Factor.


### porosity – The ratio of the voids or open spaces in alluvium and rocks to the total volume of the alluvium or rock mass. 

### possible contaminating activity (PCA) – Human activities that are actual or potential origins of contamination for a drinking water source. PCAs include sources of both microbiological and chemical contaminants that could have an adverse effect upon human health. 

### precipitation enhancement – The action of artificially stimulating clouds “cloud seeding” to produce more rainfall/snowfall than would naturally occur. Context: Resource Management Strategy. 

### prescriptive right – Rights obtained through the open and notorious adverse use of another’s water rights. By definition, adverse use is not use of a surplus, but the use of non surplus water to the direct detriment of the original rights holder

. 

### public trust doctrine– A legal doctrine recognizing public rights in the beds, banks, and waters of navigable waterways, and the State’s power and duty to exercise continued supervision over them as trustee for the benefit of the people. 

### public water system – A system for the provision of water for human consumption through pipes or other constructed conveyances that has 15 or more service connections or regularly serves at least 25 individuals daily at least 60 days out of the year. 

### pueblo right – A water right possessed by a municipality which, as a successor of a Spanish or Mexican pueblo, entitled to the beneficial use of all needed, naturally occurring surface and groundwater of the original pueblo watershed Pueblo rights are paramount to all other claims.



## R rate structure – Designates the rate basis for cost recovery (e.g., flat, uniform, tiered, etc.). Block/Tiered rates are assumed to provide cost signals to consumers. Costs can include capital, O&M, financing, environmental compliance (documentation, permitting and mitigation), etc. Context: Scenario Factor.



### real water – See new water. Context: Planning Concept/Consideration.13G **Glossary** California Water Plan Update 2005



### recharge – Water added to an aquifer or the process of adding water to an aquifer. Groundwater recharge occurs either naturally as the net gain from precipitation or artificially as the result of human influence. See also artificial recharge. 

### recharge area protection – The action of keeping recharge areas from being paved over or otherwise developed and guarding the recharge areas so they don’t become contaminated Context: Resource Management Strategy. 

### recharge basin – A surface facility constructed to infiltrate surface water into a groundwater basin.



### recoverable water – the amount of applied water that is available for supply or reuse; including surface runoff to non-saline bodies of water and deep percolation that becomes groundwater. See irrecoverable water



### recreation – Water-dependent recreation activities that are consumptive (e.g., parks), flat-water (e.g., boating), or flow-based (e.g., whitewater rafting). Context: Scenario Factor.


### recreation (reservoir-based) – Flat water recreation, such as boating and skiing, in the form of future storage facilities as well as operation of existing surfaces storage facilities. Context: 

### recreation sport-fish populations – Populations of fish species that support recreational fishing.


### recreation (watercourse-based) – Activities that are dependent on instream fl ows such as whitewater rafting. Context: 

### recycled water – Treated municipal, industrial, or agricultural wastewater to produce water that can be reused. Context: Resource Management Strategy 

### regional self-sufficiency – The degree to which a study plan involves implementation of regional water management options. Context: Evaluation Criteria. 

### reliability planning – Water reliability management planning is done by comparing the costs of taking actions to maintain or increase reliability to the costs of accepting less reliability. On this basis, accepting of the costs of adverse effects of less than 100 percent reliability could be a legitimate planning decision. Providing full water supply to meet 100 percent of projected future water demand is not the planning goal, rather, the goal is to find the justified level of reliability. Context: Planning Concept/Consideration.



### resource management strategy – A project, program, or policy that helps federal, State or local agencies manage water and related resources. Resource Management Strategies can reduce water demand, improve operational flexibility, increase water supply, improve water quality, or practice resource stewardship. 

### response packages – Additional sets of resource management strategies to be tested against future scenario conditions for performance comparison. This analysis will take place in California Water Plan Update 2010. Comparing the performance of different response packages will provide useful information to decision-makers and water managers as they choose actions to achieve a desirable future water condition. 

### return-flow system – A system of pipelines or ditches to collect and convey surface or subsurface runoff from an irrigated field for reuse. 

### reused agricultural water – Water that is used by more than one grower and is, therefore, not available for reallocation should one grower become increasingly efficient (i.e., applied water reductions minus real water equal zero). Context: Planning Concept/Consideration.California Water Plan Update 2005

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### riparian right – A right to use surface water, such right derived from the fact that the land in question abuts the banks of streams.



### root zone – The portion of the soil profile through which plant roots readily penetrate to obtain water and plant nutrients, expressed in inches or feet of depth.


### runoff – The volume of surface flow from an area.



## S safe yield – The maximum quantity of water that can be continuously withdrawn from a groundwater basin without adverse effect



### saline soil – A nonalkali soil containing soluble salts in such quantities that they inter fere with the growth of most plants.



### saline intrusion – The movement of salt water into a body of fresh water. It can occur in either surface water or groundwater bodies. 

### salinity – Generally, the concentration of mineral salts dissolved in water. Salinity may be expressed in terms of a concentration or as electrical conductivity. When describing salinity influenced by seawater, salinity often refers to the concentration of chlorides in the water.



### saturated zone – The zone in which all interconnected openings are filled with water, usually underlying the unsaturated zone.



### scenarios – Sets of plausible future conditions based on different assumptions of factors such as population size, density, and distribution, per capita income, commercial and industrial activity, and crop area and water use. In California Water Plan Update 2005, the three scenarios for 2030 are strictly narrative and are “no action” (i.e., they do not reflect any additional resource management strategies in the form of response packages beyond those currently planned, such as new water efficiency programs). 

### seasonal vs. permanent crop mix – Shifts in crop type between seasonal and permanent. This factor depicts the diminished ability to reduce water use during times of increased water scarcity (due to shifting from seasonal to permanent crops). In other words, shortage losses increase when shifting from season to permanent. Context: Scenario Factor.



### seawater intrusion barrier – A system designed to retard, cease or repel the advancement of seawater intrusion into potable groundwater supplies along coastal portions of California. The system may be a series of specifically placed injection wells where water is injected to form a hydraulic barrier. 

### secondary porosity – Voids in a rock formed after the rock has been deposited; not formed with the genesis of the rock, but later due to other processes. Fractures in granite and caverns in limestone are examples of secondary openings.



### seepage – The gradual movement of water into, through, or from a porous medium. Also, the infiltration of water into the soil from canals, ditches, laterals, watercourse, reservoir, storage facilities, or other body of water, or from a field. 

### semi-confined aquifer – A semi-confined aquifer or leaky confined aquifer is an aquifer that has aquitards either above or below that allow water to leak into or out of the aquifer depending on the direction of the hydraulic gradient.



### service area – The geographic area served by a water agency.



### soil moisture – The water in soils. Usually expressed as a percentage of the dry weight of the soil. Can also be expressed on a wet weight or a volume basis.15G **Glossary** California Water Plan Update 2005



### soil texture – Soil texture refers to the percentage of sand, silt, and clay particles in a soil. Sand, silt, and clay particles are defined by their size. Soil texture has important effects on soil properties. Water-holding capacity, drainage class, consistence, and chemical properties are just a few examples of properties that are affected by soil texture. 

### specific retention – The ratio of the volume of water a rock or sediment will retain against the pull of gravity to the total volume of the rock or sediment. 

### specific yield – the ratio of the volume of water a rock or soil will yield by gravity drainage to the total volume of the rock or soil.


### spring – a location where groundwater flows naturally to the land surface or a surface water body. 

### sprinkler irrigation – Method of irrigation in which the water is sprayed, or sprinkled, through the air to the ground surface.



### stakeholder – individuals or groups who can affect or be affected by an organization’s activities. or: Individuals or groups with an interest or “stake” in what happens as a result of any decision or action. Stakeholders do not necessarily use the products or receive the services of a program. 

### State Water Project deliveries – The volume of water imported to a given study area from the State Water Project. Context: Scenario Factor. 

### statewide water management systems – These include physical facilities (more than 1,200 State, federal, and local reservoirs, as well as canals, treatment plants, and levees), which make up the backbone of water management in California, and statewide water management programs, which include water-quality standards, monitoring programs, economic incentives, water pricing policies, and statewide water-effi ciency programs such as appliance standards, labeling, and education. 

### strategic plan – The long-term goals of an organization or program and an outline of how they will be achieved (e.g., adopting specific strategies, approaches, and methodologies). 

### stratigraphy – The science of rocks. It is concerned with the original succession and age relations of rock strata and their form, distribution, lithologic composition, fossil content, geophysical and geochemical properties—all characters and attributes of rocks as strata—and their interpretation in terms of environment and mode of origin and geologic history.


### stress irrigation – Management of irrigation water to apply less than enough water to satisfy the soil water deficiency in the entire root zone. (Preferred term is limited irrigation.) 

### subirrigation – Application of irrigation water below the ground surface by raising the water table to within or near the root zone. 

### subsurface drip irrigation – Application of water below the soil surface through emitters, with discharge rates generally in the same range as drip irrigation. This method of water application is different from and not to be confused with subirrigation where the root zone is irrigated by water table control. 

### surface irrigation – Irrigation in which the soil surface is used as the conduit, as in furrow and border irrigation, and as opposed to sprinkler, drip, and subirrigation. 

### surface storage facilities – The volume and yield of usable reservoir storage in a given area. Context: Resource Management Strategy.


### surge irrigation – A surface irrigation technique wherein flow is applied to furrows (or less commonly, borders) intermittently during a single irrigation set.California Water Plan Update 2005

16G 

### subsidence – See land subsidence



### subterranean stream – Subterranean streams “flowing through known and definite channels” are regulated by California’s surface water rights system. 

### surface supply – Water supply obtained from streams, lakes, and reservoirs. 

### surplus water – Water that is not being used directly or indirectly to benefit the environmental, agricultural or urban use sectors. Context: Planning Concept/Consideration. 

### sustainability – A specific resource that avoids complete depletion over a specified time horizon. The continued feasibility of a specified economic activity over a specified time horizon, usually influenced by management and policy actions t Context: Economic Activity.


### system reoperation – Changing existing water system operation and management procedures or priorities to either meet competing beneficial uses or derive more total benefits from the water system by operating more efficiently. Context: Resource Management Strategy.



## T third party impacts – The occurrence of incidental economic impacts to parties not directly related to (impact-causing) water management actions. For example, agricultural land retirement can impact local tax revenues and/or labor conditions, etc. Context: Evaluation Criteria. 

### total capital cost – Total monetary cost of option required for “turn key” implementation including environmental and third party impact mitigation, storage, conveyance, energy, capitalized O&M, administrative, planning, legal and engineering costs. Context: Planning Concept/Consideration. 

### total commercial activity – The amount of commercial activity (e.g., employment, productivity, commercial land use, etc) that occurs in a given study area. This factor is a driver of (and indicator for) commercial water use and includes institutional water use (government offices, schools, etc.) as well. See also commercial activity mix. Context: Scenario Factor. 

### total industrial activity – The total amount of industrial activity (e.g., employment, productivity, industrial land use, etc) that occurs in a given study area. This factor is a driver of (and indicator for) industrial water use. Context: Scenario Factor

. 

### total irrigated crop area – The total area of irrigated crops (by type) planted in a planning area during a given year. This number includes multiple cropping. Context: Scenario Factor. 

### total population – The statewide total population projection regardless of geographical distribution. Context: Scenario Factor.


### transpiration – An essential physiological process in which plant tissues give of f water vapor to the atmosphere.



## U unconfined aquifer – An aquifer which is not bounded on top by an aquitard. The upper surface of an unconfined aquifer is the water table. 

### underground stream – Body of water flowing as a definite current in a distinct channel below the surface of the ground, usually in an area characterized by joints or fi ssures. Application of the term to ordinary aquifers is incorrect.17G **Glossary** California Water Plan Update 2005



### unit applied water – The quantity of water applied to a specific crop per unit area (sometimes expressed in inches of depth).



### unsaturated zone – The zone below the land surface in which pore space contains both water and air. 

### urban land use management – Planning for the housing and economic development needs of the growing population while providing for the efficient use of water and other resources. 

### urban runoff management – A broad series of activities to manage both storm water and dry weather runoff. 

### Urban Water Management Planning Act – Sections 10610 through 10657 of the California Water Code. The Act requires urban water suppliers to prepare urban water management plans which describe and evaluate sources of water supplies, efficient uses of water, demand management measures, implementation strategies and schedules, and other relevant information and programs within their water service areas. Urban water suppliers (CWC Section 10617) are either publicly or privately owned and provide water for municipal purposes, either directly or indirectly, to more than 3,000 customers or supply more than 3,000 acre-feet of water annually. 

### [urban] water reliability (average) – A measure of a system’s ability to sustain the social, environmental and economic systems that it serves during a year of average participation. Context: Evaluation Criteria. 

### [urban] water reliability (dry) – A measure of a system’s ability to sustain the social, environmental and economic systems that it serves during a dry year. Context: Evaluation Criteria. 

### [urban] water reliability (wet) – A measure of a system’s ability to sustain the social, environmental and economic systems that it serves during a wet year. Context: Evaluation Criteria. 

### urban water use efficiency – Methods or technologies resulting in the same beneficial residential, commercial, industrial, and institutional uses with less water or increased beneficial uses from existing water quantities. Context: Scenario Factor, Resource Management Strategy. 

### usable storage capacity – The quantity of groundwater of acceptable quality that can be economically withdrawn from storage.



## V volatile organic compound (VOC) – A manmade organic compound that readily vaporizes in the atmosphere. These com pounds are often highly mobile in the groundwater system and are generally associated with industrial activities.



## W water bag transport/storage technology – Water diverted in areas that have unallocated fresh water supplies, storing the water in large inflatable bladders, and towing to an alternate coastal region. Context: Resource Management Strategy.



### water balance – An analysis of the total developed/dedicated supplies, uses, and operational characteristics for a region.



### water demand – The desired quantity of water that would be used if the water is available and a number of other factors such as price do not change. Demand is not static. 

### water demand elasticity – The desire to use water is based on a number of factors such as the intended use for the water, the price of water, and the cost of alternative ways to meet the intended use.California Water Plan Update 2005

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### water portfolio – A picture of the water supply and use for a given year statewide or by region, subject to availability of data; includes the flow diagram, fl ow diagram table, water balances, and summary table. 

### water quality – Description of the chemical, physical, and biological characteristics of water, usually in regard to its suitability for a particular purpose or use. 

### water reliability (dry) – A measure of a system’s ability to sustain the social, environmental, and economic systems that it serves during a dry year. 

### water reliability (wet) – A measure of a system’s ability to sustain the social, environmental, and economic systems which it serves during a wet year. 

### water supply exports – The amount of water that a region transfers to another to meet needs. Context: Regional Repor ts. 

### water supply imports – The amount of water that needs to be brought in from other regions to meet needs. Context: Regional Reports.



### water table – See groundwater table


### water transfers – A temporary or long-term change in the point of diversion, place of use, or purpose of use due to a transfer or exchange of water or water rights. A more general definition is that water transfers are a voluntary change in the way water is usually distributed among water users in response to water scarcity. Context: Scenario Factor, Resource Management Strategy.



### water year – A continuous 12-month period for which hydrologic records are compiled and summarized. Different agencies may use different calendar periods for their water years.



### watershed – The land area from which water drains into a stream, river, or reservoir. 

### watershed management – The process of evaluating, planning, managing, restoring, and organizing land and other resource use within an area that has a single common drainage point. Context: Resource Management strategy

.19G **Glossary** California Water Plan Update 2005

**Quantity To Convert from Metric Unit**  **To Customary Unit Multiply Metric Unit To Convert to Metric By**  **Unit Multiply Customary Unit By**  millimeters (mm) inches (in) 0.03937 25.4 Length centimeters (cm) for snow depth inches (in) 0.3937 2.54 meters (m) feet (ft) 3.2808 0.3048 kilometers (km) miles (mi) 0.62139 1.6093

Area square millimeters (mm 2 ) square inches (in 2 ) 0.00155 645.16 square meters (m 2 ) square feet (ft 2 ) 10.764 0.092903 hectares (ha) acres (ac) 2.4710 0.40469 square kilometers (km 2 ) square miles (mi 2 ) 0.3861 2.590 Volume liters (L) gallons (gal) 0.26417 3.7854 megaliters (ML) million gallons (10*) 0.26417 3.7854 cubic meters (m 3 ) cubic feet (ft 3 ) 35.315 0.028317 cubic meters (m 3 ) cubic yards (yd 3 ) 1.308 0.76455 cubic dekameters (dam 3 ) acre-feet (ac-ft) 0.8107 1.2335
Flow cubic meters per second (m 3 /s) cubic feet per second (ft 3 /s) 35.315 0.028317 liters per minute (L/mn) gallons per minute (gal/mn) 0.26417 3.7854 liters per day (L/day) gallons per day (gal/day) 0.26417 3.7854 megaliters per day (ML/day) million gallons per day (mgd) 0.26417 3.7854 cubic dekameters per day (dam 3 /day) acre-feet per day (ac-ft/day) 0.8107 1.2335
Mass kilograms (kg) pounds (lbs) 2.2046 0.45359 megagrams (Mg) tons (short, 2,000 lb.) 1.1023 0.90718 Velocity meters per second (m/s) feet per second (ft/s) 3.2808 0.3048

Power kilowatts (kW) horsepower (hp) 1.3405 0.746 Pressure kilopascals (kPa) pounds per square inch (psi) 0.14505 6.8948 kilopascals (kPa) feet head of water 0.32456 2.989 Specific liters per minute per meter drawdown gallons per minute per foot 0.08052 12.419 capacity drawdown Concentration milligrams per liter (mg/L) parts per million (ppm) 1.0 1.0 Electrical microsiemens per centimeter (μS/cm) micromhos per centimeter 1.0 1.0 conductivity (μmhos/cm) Temperature degrees Celsius (°C) degrees Fahrenheit (°F) (1.8X°C)+32 0.56(°F-32) **Metric Conversion Factors**I 1 **C hapter**  **1** Introduction California Wa ter Plan Update 200 5**Volume 3**  Strategic Plan California Wa ter Plan Update 200 5