3-65 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98



### nine RWQCBs are responsible for enforcing compliance with NPDES, including pretreatment regulations. It is, however, the responsibility of the publicly-owned wastewater treatment plants accepting industrial wastes to ensure that industries are complying with pretr eatment requirements. RWQCBs conduct regular inspections on permitted discharges and respond to public complaints on illegal discharges. Wastewater treatment facilities operated under NPDES have, in general, been successful in maintaining the quality of California’s water bodies. However, the discharge permits do not regulate all constituents that may cause adverse impacts. For example, the discharge of organic materials that contribute to the formation of DBPs in drinking water is not regulated. NPDES does not guarantee elimination of pathogens such

as Giardia and Cryptosporidium , which are harder to inactivate (disinfect) than most other waterborne pathogens. In addition, permitted discharges can include nitrogen compounds that can be harmful to aquatic life, cause algae growth in surface water bodies, and force downstream drinking water facilities to
increase their use of chlorine or to switch to alternative disinfection processes. Some wastewater treatment plant processes do not completely remove all synthetic chemicals that can be present in the water.Many municipal wastewater treatment plants discharge to surface waters which are subsequently diverted for urban use. For example, the larger wastewater treatment plants discharging to the Sacramento and San Joaquin river systems above the Delta contribute an average daily discharge volume of almost 250 mgd (280 taf/yr) to the system. Recently, there has been increasing concern about contamination of drinking water sources by methyl tertiary butyl ether. MTBE is a compound added to gasoline to promote more complete combustion and reduce exhaust emissions. In California, MTBE is used
to reduce exhaust emissions and to meet federal Clean Air Act requirements for oxygenated gasoline. MTBE is now being found in wells and reservoirs used for municipal water supply. In drinking water, MTBE causes taste and odor problems at low concentrations. The EPA drinking water advisory of 20 to 40 u g/L or below to protect consumer acceptance of drinking water (taste and odor) would also provide a large margin of protection from MTBE’s carcinogenic effects and noncancer toxicity. In California, an action level of 35 u g/L in drinking
water has been issued. To evaluate the presence of MTBE in California’s drinking water supplies, voluntary testing for MTBE was implemented in 1996 by water suppliers in response to a DHS request. In February 1997, a regulation was adopted requiring public drinking water systems to monitor their drinking water sources for MTBE as an unregulated chemical (a chemical for which there is no established regulatory or enforceable drinking water level or maximum contaminant level). Because MTBE is an unregulated chemical, water suppliers will be monitoring and reporting MTBE in sources of drinking water at least once every three years.
The most extensive MTBE contamination of drinking water sources in California was at two well fields (Charnock and Arcadia) in Santa Monica. This contamination was discovered in February 1996, not long after DHS’ request for voluntary testing for MTBE. These well fields supplied 80 percent of Santa Monica’s municipal water. MTBE concentrations as high as 610 mg/L were observed in the Charnock
well field and seven wells in the field were closed. In the Arcadia well field, two wells were closed due to contamination from an underground storage tank at a nearby gasoline station. As noted in Chapter 2, legislation enacted in 1997 required DHS to begin adopting primary and secondary drinking water standards for MTBE. The secondarydrinking water standard for MTBE was to be established by July 1, 1998, and the primary drinking water standard was to be established by July 1, 1999.
The Office of Environmental Health Hazard
Assessment released a draft technical document entitled Public Health Goal for Methyl Tertiary Butyl Ether (MTBE) in Drinking Water in April 1998. This draft document provided a review of toxicological studies and other reported data related to the adverse effects of exposures to MTBE. Based on the comprehensive review, OEHHA proposed to adopt a drinking water public health goal of 14 u g/L. PHGs adopted by OEHHA are used by DHS in establishing State MCLs. PHGs are based solely on scientific and public health considerations without regard to economic cost considerations. Drinking

water standards adopted by DHS also take into consideration factors related to economic and technical feasibility. PHGs established by OEHHA are not regulatory levels and represent only non-mandatory goals. Federal law requires that MCLs established by DHS must be at least as stringent as the federal MCL (if one exists).3-66 W

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### Establishing and Meeting Water Quality Standards

The establishment and enforcement of water quality
standards for water bodies in California falls under the authority of SWRCB and the nine RWQCBs. The RWQCBs protect water quality through adoption of region-specific water quality control plans, commonly known as basin plans. In general, water quality control plans designate beneficial uses of water and establish water quality objectives designed to protect them. The designated beneficial uses of water may vary between individual water bodies; some are listed in Table 3-26. Water quality objectives are the limits or levels of water quality constituents or characteristics which are established to protect beneficial uses. Because a particular water body may have several beneficial uses,the water quality objectives established must be protective of all designated uses. When setting water quality objectives, several sources of existing water quality limits are used (Table 3-27), depending on the uses designated in a water quality control plan. When more than one water quality limit exists for a water quality constituent or characteristic (e.g., human health limit vs. aquatic life limit), the more restrictive limit is used as the water quality objective. Table 3-28 lists some typical water quality constituents or characteristics for which water quality objectives may be established in water quality control plans. Drinking Water Standards

Drinking water standards for a total of 81 individual drinking water constituents (Table 3-29) are inplace under the mandates of the 1986 SDWA amendments. Using the new SDWA standard setting process established in the 1996 amendments, EPA will select
at least five new constituents from the candidate list published in March 1998 and will determine whether to regulate them by August 2001. EPA will publish a contaminant candidate list and select constituents for regulation every five years thereafter. The agency may promulgate an interim national primary drinking water regulation for a contaminant without making the required determination or analysis to address an urgent threat to public health. Selection of the new constituents for regulation must be geared toward contaminants posing the greatest health risks. Occasionally, drinking water regulatory goals may conflict. For example, concern over pathogens such as Cryptosporidium spurred a proposed rule requiring more rigorous disinfection. At the same time, there was considerable regulatory concern over THMs and other DBPs resulting from disinfecting drinking water with chlorine. If disinfection is made more rigorous,

T

ABLE 3-26

A Partial List of Potential Beneficial

Uses of Water

Municipal and Domestic Supply Agricultural Supply Industrial Supply Groundwater Recharge Freshwater Replenishment Navigation Hydropower Generation

Recreation Commercial and Sport Fishing Aquaculture
Freshwater Habitat
Estuarine Habitat
Wildlife Habitat Preservation of Biological Habitats of Special

Significance Preservation of Rare, Threatened, or Endangered

Species Migration of Aquatic Organisms Spawning, Reproduction, and/or Early Development Shellfish Harvesting T ABLE 3-28 A Partial List of Water Quality Constituents
or Characteristics for Which Water Quality
Objectives May Be Established

Chemical Constituents Pesticides Tastes and Odors pH Human Health and Radioactivity

Ecological Toxicity Bacteria Salinity Biostimulatory Substances Sediment
Color Settleable Material Dissolved Oxygen Suspended Material Floating Material Temperature Oil and Grease Turbidity T

ABLE 3-27 A Partial List of Existing Water Quality Limits

Drinking Water Maximum Contaminant Levels Drinking Water Maximum Contaminant Level Goals
State Action Levels and Recommended Public Health

Levels for Drinking Water EPA Health Advisories and Water Quality AdvisoriesNational Academy of Sciences Suggested No-AdverseResponse Levels Proposition 65 Regulatory Levels EPA National Ambient Water Quality Criteria3-67 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98



### DBP formation is increased. Poor quality source waters with elevated concentrations of organic precursors or bromides complicate the problem of reliably meeting standards for disinfection while meeting standards for DBPs. The regulatory community must balance benefits
and risks associated with efficient disinfection and against higher DBP levels. EPA promulgated its Information Collection Rulein 1996 to obtain data on the tradeoff posed by simultaneous control of DBPs and pathogens in drinking water. The ICR requires all large public water systems to collect and report data on the occurrence of DBPs and pathogens (including bacteria, viruses, Giardia , and Cryptosporidium ) in drinking water over an 18-month period. With this information, an assessment of health risks due to the presence of DBPs and pathogens in drinking water can be made. EPA can then determine the need to revise current drinking water filtration and disinfection requirements, and the need for more stringent regulations for disinfectants and DBPs. Source Water Protection/Watershed Management Activities

The 1996 reauthorization of the federal SDWA requires states to conduct source water assessments and encourages states to establish watershed protection programs. In response to this amendment, DHS, in cooperation with SWRCB, is preparing a drinking water source assessment and protection pr ogram. Key elements of this program include delineation of the area surrounding the water source, an inventory of possible contaminating activities, and an analysis of the vulnerability of the drinking water source to contamination. The program draft must be submittedto EPA for approval by February 1999. The assessments must be completed in 2003. California’s DWSAP program will cover both groundwater and surface water sources. Since California has not developed a wellhead protection program asrequired by the 1986 SDWA amendment, the groundT

ABLE 3-29 Constituents Regulated Under the Federal Safe Drinking Water Act a

1,1-Dichloroethylene Chromium Methoxychlor
1,1,1-Trichloroethane cis-1,2-Dichloroethylene Nickel
1,1,2-Trichloroethane Copper Nitrate 1,2-Dibromo-3-chloropropane (DBCP) Cyanide Nitrite 1,2-Dichlorobenzene Dalapon Oxamyl
1,2-Dichloroethane Dichloromethane Pentachlorophenol 1,2-Dichloropropane Dinoseb Phthalates
1,2,4-Trichlorobenzene Diquat Picloram
1,4-Dichlorobenzene Endothall Polychlorinated biphenyls (PCBs) 2,3,7,8-TCDD (Dioxin) Endrin Polynuclear Aromatic Hydrocarbons (PAHs) 2,4-Dichlorophenoxyacetic acid (2,4-D) Epichlorohydrin Radium 226 2,4,5-TP (Silvex) Ethylbenzene Radium 228 Acrylamide Ethylene dibromide (EDB) Selenium Adipates Fluoride Simazine

Alachlor Giardia lamblia Styrene Antimony Glyphosate Tetrachloroethylene

Arsenic Gross alpha particle activity Thallium

Asbestos Gross beta particle activity Toluene

Atrazine Heptachlor Total coliforms

Barium Heptachlor epoxide Total trihalomethane

Benzene Heterotrophic bacteria Toxaphene Beryllium Hexachlorobenzene trans-1,2-Dichloroethylene

Cadmium Hexachlorocyclopentadiene Trichloroethylene

Carbofuran Lead Turbidity

Carbon tetrachloride Legionella Vinyl chloride

Chlordane Lindane Viruses
Chlorobenzene Mercury Xylenes (total)

a As of February 1997.3-68 W

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### within SWP and CVP service areas outside of the Central Valley. Some water quality actions being considered by CALFED include: • Reducing concentrations of heavy metals from mine drainage entering the Delta and its tributaries. • Reducing pollutant concentrations entering the Delta from the San Joaquin River. • Reducing vulnerability of Delta water quality tosalinity intrusion by implementing a Delta longterm protection plan.• Improving water circulation in the Delta by constructing seasonally operated barriers in south
Delta channels. • Promoting and supporting efforts of local watershed programs that imp rove water quality within the Delta
and its tributaries. • Reducing urban and industrial pollutants entering the Delta and its tributaries by controlling urban
and industrial runoff. • Controlling discharge of domestic wastes from
boats within the Delta and its tributaries. • Identifying and implementing actions to address pollution problems in water and sediment within
the Delta and its tributaries. • Reducing pollutants entering the Delta and its tributaries from agricultural runoff. CALFED identified water quality parameters of
concern to beneficial uses and set numerical or narrative water quality targets for each. These targets represent desirable instream concentrations of parameters of
concern and would be used as indicators of success to determine the effectiveness of the water quality actions. However, the degree to which these targets are realized will depend upon overall CALFED solutions. Targetsmay not be fully realized because of competing CALFED solution requirements or because attainment of a target is technically infeasible. Colorado River Water Quality. The Colorado River is a major source of water supply to Southern California. The river is subject to various water quality influences because its watershed is so large. Much of the watershed is open space and agricultural lands, and municipal and industrial discharges are not a significant source of water quality degradation.
Perchlorate has been detected in the Colorado River. Concentrations ranging from 5 to 9 u g/L have
been found in Lake Havasu. The contamination source has been traced to manufacturing facilities in the Las Vegas/Henderson, Nevada, area. Several federal Superfund sites contribute to uranium contamination water portion of the DWSAP will serve as the State’s wellhead protection program. DHS is responsible for conducting drinking water source assessments, although any public water agency may perform its own assessment, provided it conforms to DHS procedures. When a public water agency has completed an evaluation through another program, that information may be submitted for the drinking water source assessment. For example, drinking water utilities that utilize surface water sources are required under California law to perform watershed sanitary surveys every 5 years. Many of the watershed sanitary surveys completed prior to the DWSAP program will likely satisfy most requirements of the assessment process. Local agencies that choose to conduct their own assessments and implement source protection may receive financial assistance through the drinking water state revolving fund loan program. The potential sources and causes of water quality impairment vary from watershed to watershed. Table 3-30 lists potential sources and causes of water quality impairment in a watershed. A Source Water Protection Example. DHS requested that the Department perform a sanitary survey of the SWP. The Department’s 1990 initial survey and 1996 update provide an example of factors considered insource protection studies. Table 3-31 lists some recommendations for action resulting from the sanitary survey. The 1996 sanitary survey identified the need to address pathogens such as Giardia and Cryptosporidium in SWP waters. The survey recommended investigating each watershed tributary to the SWP to evaluate the potential sources of pathogens and to develop a coordinated microbiological monitoring and reporting system for municipal SWP contractors and agencies. The Department and MWDSC have implemented a pathogen monitoring program. Under this program, regularly scheduled and storm event sampling for
Giardia

, Cryptosporidium , and bacteria which serve as general indicators of microbiological contamination (such as Clostridium perfringens

, Escherichia coli , and total and fecal coliforms) is conducted at sites throughout the SWP. CALFED Bay-Delta Program Water Quality Planning. CALFED’s goal for water quality is to provide good water quality for environmental, agricultural, drinking water, industrial, and recreational beneficial uses. To achieve this goal, CALFED is developing water quality actions to address impairments of beneficial uses in the Bay-Delta, Sacramento River, and San Joaquin River Watersheds, and in streams and rivers3-69 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98

T

ABLE 3-30 Potential Sources and Causes of Water Quality Impairment

Source of Pollutant or Stressor Possible Sources

Contamination
Dissolved minerals Mineral deposits, mineralized waters, hot springs,

seawater intrusion Asbestos Mine tailings, serpentinite formations Hydrogen sulfide Subsurface organic deposits, such as peat soils in Delta
islands

Metals Mine tailings Microbial agents Wildlife Radon Geologic formations
Sediment Forestry activities, stream banks, construction activities, roads, mining operations, gullies Altered flow or habitat modification Impoundments, storm water runoff, artificial drainage, bank erosion, riparian corridor modification

Gasoline Service stations’ underground storage tanks Solvents Dry cleaners, machine shops Metals Photo processors, laboratories, metal plating works

Microbial agents Sewage discharges, storm water runoff Pesticides Storm water runoff, golf courses

Nutrients Storm water runoff Miscellaneous liquid wastes Industrial discharge, household waste, septic tanks

SOCs, industrial solvents, metals, acids Electronics manufacturing, metal fabricating and plating, transformers, storage facilities, hazardous waste disposal Pesticides Chemical formulating plants Wood preservatives Plants that pressure treat power poles, wood pilings,
railroad ties

Solvents, pesticides, metals, organics, Disposal sites receive waste from a variety of industries, petroleum wastes, microbial agents municipal solid wastes, petroleum products
household waste

Pesticides, fertilizers, concentrated Tailwater runoff, agricultural chemical applications, mineral salts, microbial agents, sediment, fertilizer usage, chemical storage at farms and applicators’ nutrients air strips, packing sheds and processing plants, dairies, feed lots, pastures

Solvents, petroleum products, microbial Earthquake-caused pipeline and storage tank failures and agents, other hazardous materials damage to sewage treatment and containment facilities, major spills of hazardous materials, floodwater contamination of storage reservoirs and groundwater

sources General

Commercial

Businesses

Municipal

Industrial

Solid Waste Disposal

Agricultural

Disasters3-70 W

ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98



### in the Colorado River watershed. Uranium mining
occurs in the Colorado River Basin above Lake Mead. As uranium decays, alpha-emitting particles are released. Although gross alpha levels in Colorado River water remain under current federal and State MCLs, a slight upward trend in the levels has been observed. Salts and turbidity from natural geologic formations and from agricultural operations are the primary forms of water quality degradation in the Colorado River. Unlike Delta soils, Colorado River watershed soils are low in organic content. As a result, water from the Colorado River typically has only about one-half the capacity to produce DBPs during drinking water
treatment as does water from the Delta.
Mineral concentrations in the Colorado River are usually much higher than those found in water taken from the Delta. For example, from 1993 to 1995 the average TDS of Colorado River Aqueduct water was 691 mg/L, while the average concentration in the California Aqueduct was 236 mg/L. When possible,
MWDSC blends Colorado River water with SWP
water or other sources to reduce salt concentrations in
the water delivered to customers. MWDSC’s interim policy is to blend SWP water with Colorado River water to obtain a target TDS level between 500 and 550 mg/L, during April through September. The agency will adopt a long-term blending policy following completion of a salinity management study in 1998 (see Chapter 7). The federal Colorado River Basin Salinity Control Act of 1974 authorized and directed the Secretary of
the Interior to construct facilities to control Colorado River salinity to meet salinity requirements expressed in Minute 242 of the U.S. - Mexican Treaty. The act also directed the Secretary to expedite investigation,planning, and implementation of a salinity control program in the United States upstream of Imperial Dam. Currently, salinity control activities are removing over T

ABLE 3-31 SWP Sanitary Survey Update Recommendations

Water Quality Problem Recommendation

Pathogens Implement pathogen monitoring program

Disinfection By-Product Precursors Investigate possible means of reducing organic carbon levels in the Delta (Organic Carbon) and North Bay Aqueduct

Disinfection By-Product Precursors Investigate possible means of controlling bromide concentrations in (Bromide) SWP waters

Dissolved Solids and Turbidity in the Investigate measures to reduce salts and turbidity in the Aqueduct California Aqueduct

Hazardous Waste Facilities Inventory hazardous waste facilities and volume of hazardous materials

Hazardous Materials Releases Review emergency responses to hazardous materials releases to determine types/amounts of materials released and potential for contamination in
watershed

Urban Runoff Review storm water discharges from cities and urbanized areas

Barker Slough/North Bay Aqueduct Study watershed to determine sources and extent of contamination

Solid Waste Landfills Review solid waste landfills in SWP watersheds

Underground Storage Tanks Evaluate status of leaking underground storage tanks within
SWP watersheds

Petroleum Product Pipelines Review pipeline failures resulting in petroleum releases to determine potential for SWP contamination

Emergency Action Plan Review SWP emergency action plan to ensure document is up-to-date and functionally adequate3-71 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98



### 600,000 tons of salt per year from the river system. To maintain the 1975 federally approved salinity standards for the basin it is estimated that by 2010 approximately 1.5 million tons of salt will have to be removed each year. An example of a salinity control measure in the basin is USBR’s Yuma desalting plant, constructed totreat agricultural drainage from Arizona’s WelltonMohawk Irrigation and Drainage District. The plant, said to be the world’s largest reverse osmosis desalter, has a capacity of 73 mgd. Plant construction was completed in 1992, and USBR began operating the plant at one-third capacity. A flood event in the Gila River along with above normal runoff in the Colorado River watershed in years since then has reduced the salinity of Colorado River water, permitting the plant to be taken off-line. Currently, agricultural drainage is bypassed through a concrete-lined canal to the Cienega de Santa Clara in Mexico, as long as Minute 242 water quality requirements are being met. Other salinity control measures implemented in Wyoming, Utah, Colorado, and Nevada have included lining or piping irrigation delivery systems, deep well injection of brines, plugging of flowing brine wells, erosion control on saline lands, and irrigation improvements.

Groundwater Quality
Groundwater pollution presents a serious challenge in California. A variety of contaminants have been found in groundwater; most have been introduced by human activities. Prominent among these are nitrates and chemicals such as pesticides and solvents. Most groundwater contamination sites are small and seldom affect water supplies on a regional basis. These sites may require cessation of pumping from one or two water supply wells, or the installation of wellhead treatment.

T

ABLE 3-32

Waterborne-Disease Outbreaks Associated with Groundwater
Used as a Drinking Water Source, 1993-94

State Date Pathogen Organism No. of Type Cases

Minnesota November 1993 Campylobacter jejuni Bacterium 32
Missouri November 1993 Salmonella serotype Typhimurium Bacterium 625
New York June 1993 Campylobacter jejuni Bacterium 172 Pennsylvania January 1993 Giardia lamblia Protozoan 20 South Dakota September 1993 Giardia lamblia Protozoan 7 Washington April 1993 Cryptosporidium parvum Protozoan 7 Idaho June 1994 Shigella flexneri Bacterium 33

Minnesota June 1994 Campylobacter jejuni Bacterium 19 New York June 1994 Shigella sonnei Bacterium 230 Washington August 1994 Cryptosporidium parvum Protozoan 134 

### Of greater water supply concern from a statewideperspective are areas of regional groundwater contamination—such as organics in the San Gabriel Valley ornitrates in parts of the San Joaquin Valley—which require a significant reconfiguration of local agency water supply systems. Another important consideration in evaluating larger-scale groundwater contamination problems is the treatment preference now accorded to groundwater sources under the SDWA. Because the SDWA is imposing more stringent requirements on treatment of drinking water from surface sources, many communities are planning to meet their future municipal needs by turning to groundwater.In California, nitrates in groundwater are widespread (see Chapter 5). Nitrates may enter the soil as a result of fertilizer application, animal waste, septic tanks, industrial disposal, wastewater treatment plant sludge application, or other sources. Certain organisms have the capacity to take nitrogen from the air and

convert it to nitrates. In California, the most significant source of nitrates in soils is from agricultural practices, primarily farming operations and animal husbandry. Nitrates can move through the soil into groundwater and, once there, may seriously degrade its usability. Nitrate removal is expensive; therefore, it is often not
cost effective to treat nitrate-contaminated waters. There has been growing concern over the potential human health threat of pathogens in groundwater used as drinking water. This concern stems from pathogens
such as Giardia

, Cryptosporidium , bacteria, and viruses being found in well water. Several waterborne-disease outbreaks associated with groundwater have been reported outside California. Some of these outbreaks are listed in Table 3-32. Concern about pathogens in groundwater has led3-72 W

ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98



### to regulatory discussions on disinfection requirements for groundwater. EPA is currently developing a Groundwater Disinfection Rule proposal for release in March 1999, with a final rule by November 2000. Data obtained through the ICR will provide information to assess the extent and severity of risk. The SDWA requires states to implement wellheadprotection programs designed to prevent the contamination of groundwater supplying public drinking water wells. Wellhead protection programs rely heavily on local efforts to be effective, because communities have primary access to information on potential contamination sources and can adopt locally-based measures to manage these potential contaminationsources. EPA has recommended five steps that communities can take to implement wellhead protection: • Form a community planning organization. • Define the land area around the well to be protected. • Identify potential sources of contamination within
the area. • Develop and implement a management plan to protect the area. • Plan for emergencies and future water supply needs. Water Supply Summary by Hydrologic Region

This chapter described how the State’s water supplies are affected by climate and hydrology, how water supplies are calculated, and how water supplies are reallocated through storage and conveyance facilities and through water transfers. Also, this chapter discussed water quality considerations that affect beneficial uses of California’s water supplies. Table 3-33 summarizes average year water supplies by hydrologic region assuming 1995 and 2020 levels of development and existing facilities and programs. Similarly, Table 3-34 summarizes drought year water supplies by hydrologic region for existing and future levels of development. Regional water supplies, along with water demands presented in the following chapter, provide the basis for the statewide water budget developed in Chapter 6 and regional water budgets developed in Chapters 7-9.3-73 W ATER S UPPLIES The California Water Plan Update B ULLETIN 160-98TABLE3-33California Average Year Water Supplies by Hydrologic Region (with existing facilities and programs, in taf)19952020Region Surface GroundwateraRecycled & TotalSurface GroundwateraRecycled & TotalDesalted (rounded)Desalted (rounded)North Coast20,3312631320,61020,3712881320,670San Francisco Bay 7,01168357,1107,06772377,180Central Coast3181,045181,3803681,041421,450South Coast3,8391,1772075,2203,6251,2432735,140Sacramento River 11,8812,672014,55012,1962,636014,830San Joaquin River 8,5622,195010,7608,4582,295010,750Tulare Lake7,8884,340012,2307,7914,386012,180North Lahontan77715789407591838950South Lahontan3222392759043724827710Colorado River4,154337154,5103,920285154,220Total (rounded) 65,09012,49032077,90064,99012,68041078,080aExcludes groundwater overdraft.TABLE3-34California Drought Year Water Supplies by Hydrologic Region (with existing facilities and programs, in taf)19952020Region Surface GroundwateraRecycled & TotalSurface GroundwateraRecycled & TotalDesalted (rounded)Desalted (rounded)North Coast10,1832941410,49010,2123211410,550San Francisco Bay 5,28592355,4105,41789375,540Central Coast1601,142261,3301801,159421,380South Coast3,1961,3712074,7803,1301,4622734,870Sacramento River 10,0223,218013,24010,0123,281013,290San Joaquin River 6,0432,90008,9405,9862,91208,900Tulare Lake3,6935,97009,6603,5935,99909,590North Lahontan55718787505572088770South Lahontan2592732756032629627650Colorado River4,128337154,4803,909284154,210Total (rounded) 43,53015,78033059,64043,32016,01042059,750aExcludes groundwater overdraft.3-74 W

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# Urban, Agricultural, and Environmental Water Use 

# T his chapter describes present and forecasted urban, agricultural, and environmental

water use. The chapter is organized into three major sections, one for each

category of water use.

Water use information is presented at the hydrologic region level of detail under normalized

hydrologic conditions. Forecasted 2020-level urban and agricultural water use have not changed

greatly since publication of Bulletin 160-93. Forecasted urban water use depends heavily on

population forecasts. Although the DOF has updated its California population projections since

the last Bulletin, U.S. census data are an important foundation for the projections, and a new census

will not be performed until 2000. The Department’s forecasts of agricultural water use change

relatively slowly in the short-term because the corresponding changes in forecasted agricultural acreage are a small percentage of the State’s total irrigated acreage. Changes

in base year and forecasted environmental water use from the last Bulletin reflect implementation of SWRCB’s Order WR 95-6 for the Bay-Delta. Nursery products are California’s third
largest farm product

in gross value. The nursery industry is
affected by the
availability of both agricultural and
urban water supplies.4-2 W

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### Water Use Calculation
The urban, agricultural, and environmental water uses calculated in this chapter are combined withwater supply information (Chapter 3) to form statewide balances (Chapter 6) and regional balances (Chapters 7-9). As noted in the Chapter 3 discussion of water supplies, Bulletin 160-98 water balances are computed with applied water data, instead of the net water data used in previous editions of the Bulletin. Figure 4-1 shows statewide water use in terms ofapplied water and depletions. The two methods provide similar results at a statewide level. (The largedepletion associated with environmental water use reflects the magnitude of wild and scenic river outflow to the Pacific Ocean, as discussed later in the chapter.)For purposes of presentation in the Bulletin, urban, agricultural, and environmental water uses are treated separately. In reality, these uses are usually linked by California’s hydrologic system. As discussed in Chapter 3, the return flow from one water user oftenbecomes the supply for a downstream user. The applied water budgets used in Bulletin 160-98 reflect the multiple uses of water in a river basin. Water supplies in a river basin may count toward meeting wild and scenic river use in the Sierra Nevada foothills, count toward urban and/or agricultural uses on the CentralValley floor, and count toward meeting Bay-Delta outflow farther downstream. Another change from Bulletin 160-93 was eliminating the “other” water use category to simplifyinformation presentation. This category included major canal conveyance losses, recreation use, cooling water use, energy recovery use, and use by high water using industries. Water uses previously categorized as“other” are now included in urban, agricultural, or environmental water use, according to their intended purpose. At a statewide level, the magnitude of these other uses is small in comparison to that of the major categories.

Land Use Considerations
It is important to understand how urban, agricultural, and environmental water use are shaped by land use patterns and land use planning. Patterns of future development and water use trends are dictated by city and county land use planning decisions. Urbanization of agricultural lands, open space preservation, habitatcreation, and wetlands preservation policies are examples of land use-related decisions that have water use implications.DOF forecasts that California’s population will increase by more than 15 million people by 2020. Where these additional people live affects statewide urbanwater use. For example, in terms of percent population increase, DOF forecasts that the City and County of San Francisco will have one of the slowest growth rates statewide. Adjoining Bay Area counties are alsoforecasted to grow slowly, reflecting the region’s intensive urbanization and relatively small amounts ofremaining undeveloped land. Areas expected to experience high growth rates include some San JoaquinValley counties and the Inland Empire region in SouthSummary of Key Statistics

Shown below for quick reference are some key statistics presented in this chapter. Water use information values shown are for applied water use in average water year conditions. The details behind the statistics are discussed later.

1995 2020 Change

Population (million) 32.1 47.5 +15.4 Irrigated crops (million acres) 9.5 9.2 -0.3 Urban water use (maf) 8.8 12.0 +3.2 Agricultural water use (maf) 33.8 31.5 -2.3 Environmental water use (maf) 36.9 37.0 +0.1

Percent of total Urban water use (%) 11 15 +4 Agricultural water use (%) 43 39 -4 Environmental water use (%) 46 46 04-3 W ATER U SE The California Water Plan Update B ULLETIN 160-98

Future land use patterns are important in forecasting future water use. How and where presently undeveloped lands are developed—or are preserved from development—affects water use calculations.

1995 APPLIED WATER 2020

Agricultural Environmental Urban
11%

43% 46% Agricultural Environmental Urban
15%

39% 46%

1995 DEPLETION 2020

Agricultural Environmental Urban
11%

43% 46% Agricultural Environmental Urban
15%

40% 45% F IGURE 4-1
California Applied Water Use and Depletion4-4 W

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### capita water use estimates at a statewide level of detail. An urban water agency making estimates for its ownservice area would be able to incorporate more complexity in its forecasting because the scope of its effortis narrow. For this reason, and because DOF population projections seldom exactly match population projections prepared by cities and counties, theBulletin’s water use forecasts are expected to be representative of, rather than identical to, those of local water agencies.

Population Growth
Data about California’s population—its geographic distribution and projections of future population and their distribution—come from several sources. The Department works with base year and projected year population information developed by DOF for each county in the State. The decadal census is a major benchmark for population projections. DOFworks from census data to calculate the State’s population in noncensus years, and to project future populations. Figure 4-2 shows DOF’s projected growth rates by county for year 2020. (State policy requires that all State agencies use DOF population projections for planning, funding, and policy making activities.)DOF uses as its starting population the 1990 census, modified by the Bureau of the Census for known misreporting. (These counts represent a modification to the age distribution of the census count and not an adjustment for undercount to the total.) Between 1950 and 1980 the birthrate in California mirrored the nation’s. A sharp divergence began during the 1980s;
the nation’s birthrate was flat while the birthrate in California rose sharply. California’s annual growth rate was 2 to 3 percent throughout the 1980s. After 1990, the rate slowed to 1.3 percent and the State’s population grew by only 2 million, for a 1995 population of 32.1 million. California’s growth since 1992 has also been affected by lower than projected natural increase (births minusdeaths) and net migration. Domestic migration patterns tend to parallel the unemployment differential rate between California and other states. Between 1990 and 1994, California lost more than 700,000 jobs due to the economic recession. This job loss resulted in a new demographic phenomenon for California—a net migration of California residents to other states. By 1996, California had replaced the jobs lost during the

recession. Migration is the most volatile component of ern California. This population shift to warmer, drier inland areas where urban outdoor water use is higher
affects future statewide water demands. The location of urban development also affectsagricultural water use. For example, subdivisions constructed on non-irrigated grazing lands do not directly displace agricultural use (although they may compete with existing agricultural water users for a supply). Subdivisions constructed on irrigated farmland result in direct conversion of water use from agricultural to urban. Bulletin 160-98 forecasts a statewide decline in irrigated acreage by 2020. Most of that decline isthe result of expected urbanization of irrigated agricultural lands, especially in the San Joaquin Valley and South Coast areas. (To some extent, urbanization mayshift agricultural development to presently undeveloped lands, but such lands are usually of lower quality and can economically support only limited crop types.)Local open space preservation goals can affect the extent of land use conversion. Williamson Act contractsare a commonly used means of encouraging preservation of agricultural land use, especially for agriculturallands near urban areas. Not all open space preservation goals affect water use. For example, some land use planning agencies in urban areas have set aside ridgetop areas as lands to be managed for recreation or open space to preserve viewsheds. If the areas setaside are non-irrigated grazing lands, water use impacts are minimal. Policies to preserve and enhance wetlands can entail creating new wetlands or providing increased water supplies to existing wetlands, thus increasingenvironmental water use, often by conversion of agricultural water supplies. Programs creating new wildlife habitat areas would entail conversion of agricultural lands and water supplies to environmental uses.

Urban Water Use

Forecasts of urban water use for the Bulletin arebased on population information and per capita water use estimates, as described later in this section.Factors influencing per capita water use include expected demand reduction due to implementation of water conservation programs. The Department has
modeled effects of conservation measures and socioeconomic changes on per capita use in 20 major water service areas to estimate future changes in per capita use by hydrologic region. The Department’s Bulletin 160 series makes per4-5 W ATER U SE The California Water Plan Update B ULLETIN 160-98

F IGURE 4-2 Projected Growth Rates by County, 1995-2020

0 - 20%

20 - 40%

40 - 60%

60 - 80%

80 - 100%

Over 100% 

# Legend Legend4-6 W

ATER U SE The California Water Plan Update B ULLETIN 160-98



### population change. Migrants are separated into two categories: domestic (from other states) or foreign (fromother countries). Since 1980, approximately 30 percent of net migration has been domestic and 70 percentforeign. DOF attributes fluctuations in migration primarily to domestic migration, since undocumented migration has been fairly constant and legal foreignmigration has slowly increased. Figure 4-3 shows natural increase and net migration for the years 1940-95. DOF uses a baseline cohort-component method to project population by gender, race/ethnicity, and age. A baseline projection assumes people have the right to migrate where they choose and no major natural catastrophes or wars will occur. A cohort-component method traces people born in a given year throughout their lives. As each year passes, cohorts change due to mortality and migration assumptions. New cohorts are formed by applying birthrate assumptions to womenof childbearing age. Special populations display different demographic behavior and other characteristics and must be projected separately. The primary sourcesof special populations are prisons, colleges, and military installations. Population projections used in Bulletin 160-98 are
based on DOF’s Interim County Population Projections (April 1997). Table 4-1 shows the 1995 through 2020 population figures for Bulletin 160-98 by hydrologic Urban water demand forecasts are driven by the expected increase in California’s population—more than 15 million new residents by 2020. Multipurpose reservoirs help meet needs for water-based recreational opportunities, especially in arid Southern California. -200 0 200 400 600 800 1000

1995 1990 1985 1980 1975 1970 1965 1960 1955 1950 1945 1940 Components of Population Growth, 1940-1995 F IGURE 4-3A n n u a l P o p u l a t i o n C h a n g e i n T h o u s a n d s

Net Migration and Natural Increase

Net Migration4-7 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### region. DOF periodically updates its population forecasts to respond to changing conditions. Its 2020 population forecast used for Bulletin 160-93 was 1.4 million higher than the 2020 forecast used in Bulletin 160-98. The latter forecast incorporated the effects of the recession of the early 1990s. Small fluctuations in
the forecast do not obscure the overall trend—an increase in population on the order of 50 percent. The Department apportioned county population data to Bulletin 160 study areas based on watershed
or water district boundaries. Factors considered in distributing the data to Bulletin 160 study areas included population projections prepared by cities, counties, and local councils of governments, which typically incorporate expected future development from city and county general plans. The local agency projections indicate which areas within a county are expected to experience growth and provide guidance in allocating DOF’s projection for an entire countyinto smaller Bulletin 160 study areas. Table 4-2 compares DOF interim projections with councils of governments projections. Factors Affecting Urban Per Capita Water Use
Urban per capita water use includes residential,commercial, industrial, and institutional uses of water. Each of these categories can be examined at a greaterlevel of detail. Residential water use, for example, includes interior and exterior (e.g., landscaping) water
use. Forecasts of urban water use for an individual community may be separated into components and forecasted individually. It is not possible to use thislevel of detail for each community in the State in Bulletin 160-98. Bulletin 160-98 modeled components of urban use for representative urban water agenciesin each of the State’s ten hydrologic regions and extrapolated those results to the remainder of each hydrologic region, as described later in the chapter. Demand reduction achieved by implementingwater conservation measures is important in forecasting per capita water use. Bulletin 160-98 incorporates demand reductions from implementation of urban best management practices contained in the 1991 Memorandum of Understanding Regarding Urban Water Conservation in California. Bulletin 160-98 assumes implementation of the urban MOU’s BMPs by 2020, resulting in a demand reduction of about 1.5 maf overthe year 2020 demand forecast without BMP implementation. The following subsections detail existingurban water conservation programs and estimated demand reductions. For simplicity of presentation,conservation plans required of USBR water contractors are described in the agricultural water conservation section, since agricultural water supply comprises the majority of CVP water contracts. USBR’s urban watercontractors are also required to comply with these requirements.The relationship of water pricing to water consumption, and the role of pricing in achieving waterconservation, has been a subject of discussion in recent years. Elected board members of public water

T

ABLE 4-2
Comparison Between Department of Finance and Councils of Governments Population Projections

(in thousands)

1990 Census 2010 Projections a

DOF COG

Southern California Counties 17,139 23,352 24,038 Bay Area Counties 6,020 7,489 7,540
Central Coast Counties 1,172 1,508 1,518
Greater Sacramento Counties 1,684 2,542 2,586 San Joaquin Valley Counties 2,742 4,608 4,641

a COG data were only available for 2010, thus 2010 COG forecasts are compared with DOF 2010 forecasts. T

ABLE 4-1
California Population by Hydrologic Region

(in thousands)

Region 1995 2020

North Coast 606 835 San Francisco Bay 5,780 7,025
Central Coast 1,347 1,946
South Coast 17,299 24,327 Sacramento River 2,372 3,813 San Joaquin River 1,592 3,025 Tulare Lake 1,738 3,296
North Lahontan 84 125 South Lahontan 713 2,019 Colorado River 533 1,096 Total (rounded) 32,060 47,5104-8 W

ATER U SE The California Water Plan Update B ULLETIN 160-98



### agencies ultimately have the responsibility for balancing desires to achieve demand reduction through water pricing with desires to provide affordable water rates to consumers. Urban water rates in California vary widely and are affected by factors such as geographic location, source of supply, and type of water treatmentprovided. Water rates are set by local agencies to recover costs of providing water service and are highlysite-specific. Appendix 4A provides background information on urban water pricing. As described in theappendix’s summary of price elasticity studies for urban water use, residential water demand is inelastic in most cases—water users were relatively insensitive to changes in price, for the price ranges evaluated. Waterprice plays a small role in relation to other factors affecting water use, such as public education and plumbing retrofit programs.
Urban Water Conservation Actions. State and federal legislation imposed standards to improve the water use efficiency of plumbing fixtures, requiring thatfixtures manufactured, sold, or installed after specified dates meet the targets shown in Table 4-3. Theserequirements apply to new construction or to retrofitting existing plumbing fixtures, but do not requireremoval and replacement of existing fixtures. One water conservation action being taken by urban wateragencies is to sponsor programs for voluntary retrofitting of fixtures, to accelerate demand reductions. (This
action is one of the BMPs included in the urban MOU.) Some water purveyors, such as the City and County of San Francisco, have regulations requiring
retrofit when homes are sold. More than 200 urban water suppliers have signed
the urban MOU and are now members of the California Urban Water Conservation Council. Some key points from the MOU are highlighted in the sidebar. Water suppliers signing the urban MOU committed to implement BMPs unless a cost-benefit analysis conducted according to CUWCC guidelines showed individual BMPs not to be cost-effective, or unless there was a legal barrier to implementation. The MOU also committed CUWCC to study measures that could be added as new BMPs, such as establishing efficiency standards for water-using appliances. The urban use forecasts in Bulletin 160-98 assume that water users statewide will implement BMPs by 2020, as set forth in Exhibit 1 of the MOU, whether or not the BMPs are cost-effective from a water supply standpoint. In making this assumption, the Bulletinrecognizes that water conservation measures have potential benefits in addition to water supply, such as reduced water and wastewater treatment costs, other water quality improvements, reduced entrainment of fish at urban points of diversion, and greater control of temperature and timing of wastewater discharges.The Department believes this assumption is reasonable, given that funding sources for non-water supply benefits could help support BMP implementation, andthat the planning horizon over which the Bulletin assumes that BMPs would be implemented (from 1995 to 2020) provides more time for implementation than does the MOU. The widespread acceptance that theexisting BMPs have achieved, as evidenced by the number of MOU signatories, indicates that the BMPs are generally considered to be technologically feasible, sotechnology should not be a limiting factor in implementation.Quantifying demand reduction from implementation of some BMPs is difficult (for example, public information programs and water education in schools). These actions contribute to implementation of otherBMPs, such as demand reduction from installing water meters, but do not by themselves save quantifiable amounts of water. CUWCC reviewed implementation Landscape Water Use

The Model Water Efficient Landscape Ordinance was added to Title 23 of the California Code of Regulations in response to requirements of the 1990 Water Conservation in Landscaping Act. Local agencies that did not adopt their own ordinances by January 1993 were required to begin
enforcement of the model ordinance as of that date.

The model ordinance applies to all new and rehabilitated landscaping (more than 2,500 square feet in size) for public agency projects and private development projects that require a local agency permit, and to developer-installed landscaping for single-family and multifamily residential projects. The purpose of the ordinance was to promote water efficient landscape design, installation, and maintenance. The general approach of the ordinance was to use 0.8 ET

0 as a water use goal for new and renovated landscapes. (ET

0 is a reference evapotranspiration, established according to specific criteria.) Tools to help meet that goal include proper landscape and irrigation system design.

To date, there has been no statewide-level review of how cities and counties are implementing this requirement; thus, its water savings potential remains to be quantified.4-9 W ATER U SE The California Water Plan Update B ULLETIN 160-98

T

ABLE 4-3
Summary of California and Federal Plumbing Fixture Requirements

Energy California Policy Act of 1992 Plumbing Device (covers sale and Effective Date (covers only installation) manufacture)

Showerheads 2.5 gpm CA 3/20/92 US 1/1/94 2.5 gpm

Lavatory Faucets a 2.75 gpm CA 12/22/78 2.2 gpm CA 3/20/92 US 1/1/94 2.5 gpm

Sink Faucets a 2.2 gpm CA 3/20/92 US 1/1/94 2.5 gpm

Metering (self-closing) hot water maximum CA 7/1/92

Faucets b flow rates range from US 1/1/94 0.25 gallons/cycle (public restrooms) 0.25 to 0.75 gallons/ (maximum water cycle and/or from 0.5 delivery per cycle) gpm to 2.5 gpm, depending on controls and hot water system

Tub Spout Diverter a 0.1 (new), to 0.3 gpm CA 3/20/92 (does not appear to be (after 15,000 cycles included in EPA) of diverting)

Toilets 1.6 gpf CA 1/1/92 (new (residential) construction) CA 1/1/94 (all toilets for sale or installation) US 1/1/94 (non- 1.6 gpf commercial)

Flushometer valves a 1.6 gpf CA 1/1/92 (new construction) CA 1/1/94 (all toilets) US 1/1/94 (commercial) 3.5 gpf US 1/1/97 (commercial) 1.6 gpf

Toilets 1.6 gpf CA 1/1/94 (all toilets for (Commercial) a sale or installation) US 1/1/97 1.6 gpf

Urinals 1.0 gpf CA 1/1/92 (new) CA 1/1/94 (all) US 1/1/94 1.0 gpf

a California requirements are preexisting and more stringent than federal law; therefore California requirements prevail in California.

b Federal law is more stringent than California requirements.4-10 W

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### and quantification of the initial BMPs, and developed a strategic plan in 1996 that included evaluating theBMPs and revising them to make them easier to quantify. The revised BMPs (see sidebar) were adopted by CUWCC in September 1997. The revisions included restructuring the original 16 BMPs to 14 BMPs (newBMPs were also added—rebate programs for high efficiency washing machines and wholesale water agencyassistance to retail water agencies), revising implementation schedules and coverage requirements, and adding new evaluation criteria. Implementation of some BMPs was extended beyond the original 10-year term of the existing MOU. Appendix 4B presents a synopsis of
the revisions. Local agencies were required by the 1990 Water Conservation in Landscaping Act to enforce ordinances intended to promote water-efficient designs. The act’s requirements apply to landscapes greater than 2,500 sq. ft. in size.

Urban Best Management Practices (1997 Revision)

BMP 1 Water Audit Programs for Single-Family Residential and Multifamily Residential Customers BMP 2 Residential Plumbing Retrofit BMP 3 System Water Audits, Leak Detection and Repair BMP 4 Metering With Commodity Rates for All New Connections and Retrofit of Existing Connections BMP 5 Large Landscape Conservation Programs and Incentives BMP 6 High-Efficiency Washing Machine Rebate Programs (New) BMP 7 Public Information Programs BMP 8 School Education Programs BMP 9 Conservation Programs for Commercial, Industrial, and Institutional Accounts BMP 10 Wholesale Agency Assistance Programs (New) BMP 11 Conservation Pricing BMP 12 Conservation Coordinator (Formerly BMP 14)
BMP 13 Water Waste Prohibition BMP 14 Residential ULFT Replacement Programs (Formerly BMP 16)4-11 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### Bulletin 160-98 estimates water savings due to BMP implementation based on the assumptions set forth in Exhibit 1 of the urban MOU, and assumes
that California will achieve a level of water conservation equivalent to that expected from full BMPimplementation by 2020. The MOU specifies implementation schedules, water use reduction factors, andinstallation and/or compliance rates that allow quantification of water savings for 7 of the 14 BMPs. The MOU identifies the remaining BMPs as not having quantifiable water savings. The Bulletin’s estimated water savings (Appendix 4B) are based on evaluation of the following BMPs in accordance with the Exhibit 1 provisions: residential water use surveys, residential plumbing retrofits, distribution system water audits/ leak detection/repairs, metering with commodity rates,programs for commercial/industrial/institutional accounts, and residential ultra-low flush toiletreplacement. Water savings for the BMP on large landscape water conservation (3 acres or greater) could not be evaluated due to lack of data on existing irrigated landscape acreage. BMP implementation is estimated to result in astatewide 2020 demand reduction of 1.5 maf statewide. As discussed in Chapter 6, this demand reduction is not the same as creating new water supply. Only
conservation actions that reduce irrecoverable losses or reduce depletions actually create new water supply from a statewide perspective. Table 4-4 shows appliedwater and depletion reductions due to BMP implementation by hydrologic region.As more water conservation measures are implemented, especially structural changes such as plumbingretrofits, it will become increasingly difficult for urban water agencies and their customers to achieve drought year demand reductions. Demand hardening is discussed in more detail in Chapter 6. The urban MOU acknowledges that demand hardening will be a Highlights of the Urban MOU Shown below are several excerpts from the urban
MOU that are relevant to the water conservation measures discussed in Chapters 4 and 6.

Recital F It is the intent of this MOU that individual signatory water suppliers (1) develop comprehensive conservation BMP programs using sound economic criteria and (2) consider water conservation on an equal basis with other water management options.

Recital G It is recognized that present urban water use throughout the State varies according to many factors including, but not limited to, climate, types of housing and landscaping, amounts and kinds of commercial, industrial and recreational development, and the extent to which conservation measures have already been implemented. It is further recognized that many of the BMPs identified in Exhibit 1 to this MOU have already been implemented in some areas and that even with broader employment of BMPs, future urban water use will continue to vary from area to area. Therefore, this MOU is not intended to establish uniform per capita water use allotments throughout the urban areas of the State. This MOU is also not intended to limit the amount or types of conservation a water supplier can pursue or to limit a water supplier’s more rapid implementation of BMPs.

Section 4.1 (c) Assumptions for use in developing estimates of reliable savings from the implementation of BMPs. Estimates of reliable savings are the water conservation savings which can be achieved with a high degree of confidence in a given service area. The estimate of reliable savings for each BMP depends upon the nature of the BMP and upon the amount of data available to evaluate potential savings. For some BMPs (e.g., public information) estimates of reliable savings may never be generated. For others, additional data may lead to significant changes in the estimate of reliable savings. It is probable that average savings achieved by water suppliers will exceed the estimates of reliable savings.

Section 4.5 Exemptions. A signatory water supplier will be exempt from the implementation of specific BMPs for as long as the supplier substantiates each reporting period that, based upon then prevailing local conditions, one or more of the following findings applies: (a) A full cost-benefit analysis, performed in accordance with the principles set forth in Exhibit 3, demonstrates that either the program (i) would not be cost-effective overall when total program benefits and costs are considered; OR (ii) would not be cost-effective to the individual water supplier even after the water supplier has made a good faith effort to share costs with other program beneficiaries.

(b) Adequate funds are not and cannot reasonably be made available from sources accessible to the water supplier including funds from other entities. However, this exemption cannot be used if a new, less cost-effective water management option would be implemented instead of the BMP for which the water supplier is seeking this exemption.

(c) Implementation of the BMP is (i) not within the legal authority of the water supplier; and (ii) the water supplier has made a good faith effort to work with other entities that have the legal authority to carry out the BMP; and (iii) the water supplier has made a good faith effort to work with other relevant entities to encourage the removal of institutional barriers to the implementation of BMPs within its service area.4-12 W

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### consequence of BMP implementation.Although there are other urban water conservation programs besides those associated with the urbanMOU, only the MOU presently addresses quantification of water savings. EPA has started developing water conservation guidelines pursuant to Section 1455 of the 1996 SDWA. USBR has developed guidelines for Reclamation Reform Act water conservation plans and for the more detailed conservation plans required by CVPIA. The USBR conservation plans apply to both urban and agricultural contractors, and aredescribed in more detail in a later section on agricultural water conservation.Effects of Droughts on Urban Water Production. To illustrate the effects of droughts, Figure 4-4 shows statewide per capita urban water production over time. (Per capita production is the water provided by urban suppliers, divided by population. Urban water production is not the same as total urban water use;total use includes self-produced supplies, water for recreation and energy production uses, and losses from major conveyance facilities.) After the severe, but brief,1976-77 drought, statewide urban per capita water production rates returned to pre-drought levels within 3 to 4 years. During the longer 1987-92 drought, urban per capita water production rates declined by about19 percent on the average statewide. (Most requirements for water-conserving plumbing fixtures did not take effect until after the 1987-92 drought.) The Department’s data show increases in per capita water production following the drought, due to removal ofmandatory water rationing and other short-term restrictions. When viewed at a statewide level, the data show a strong response to hydrologic conditions.

Urban Water Use Planning Activities
The Department has surveyed retail water agencies and analyzed their water production data for more than 35 years, publishing the data in the Bulletin 166 series, Urban Water Use in California. Bulletin 166-4, published in 1994, summarized monthly urban water production data from 1980-90 for nearly 300 retail water purveyors throughout the State. This water useinformation, updated in the Department’s annual surveys, is a primary data source for water use estimatesmade for Bulletin 160. The Department also conducted a statewide survey of industrial water use bywater-using sector in 1994. Industrial water use information is periodically published in the Department’s Bulletin 124 series, Industrial Water Use in California.The Urban Water Management Planning Act requires that urban water suppliers with 3,000 or more connections, or that deliver over3 taf of water per year, prepare urban water management plans and submit them to the Department. The initial set of plans was due in 1985; plans are to be updated every five years. Table 4-5 shows the number of agencies affected by the law and those submitting their 1995 plans as of March 1997. The 1995 plans received were from agencies representingalmost 90 percent of all urban water deliveries. These plans have multiple purposes, including demonstrating how local agencies T

ABLE 4-4
Annual Reductions in Applied Water and
Depletions Due to BMP Implementation by

2020 (taf)

Region Applied Water Depletion

North Coast 20 11 San Francisco Bay 176 172 Central Coast 48 30 South Coast 768 500
Sacramento River 91 0 San Joaquin River 111 30 Tulare Lake 125 50 North Lahontan 5 2 South Lahontan 59 21 Colorado River 111 52 Total 1,514 868

150 200 250

95 90 85 80 75 70 65 60 5550 45 1940 Statewide Average Per Capita Urban Water Production Over Time F IGURE 4-4G a l l o n s P e r C a p i t a P e r D a y4-13 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### propose to implement water conservation measures andhow the agencies plan to meet drought year water supply reliability goals. The CALFED Bay-Delta program includes wateruse efficiency—urban, agricultural, and environmental—as one of the common elements required for all proposed Delta alternatives. As described in the water use efficiency technical appendix for the March 1998 draft programmatic EIR/EIS, potential elements of an urban water use efficiency program include: • Requirements that urban water management plans be implemented more vigorously and that the Department review and certify those plans.
• Revisions to the BMPs to make them more quantifiable. • Requirements that CUWCC certify BMP implementation.
• Provision of financial and technical assistance towater agencies to encourage program implementation. CALFED is also examining ways to require that the urban water use efficiency program be implemented vigorously. For example, urban water agencies thatchoose not to implement the program could be excluded from participation in water transfers requiring approval by a CALFED agency, from use of facilities operated by a CALFED agency, from new suppliesmade available by a CALFED actions, or from participating in certain loan and grant programs. In addition, CALFED has suggested that SWRCB could be askedto pursue its obligations to investigate waste and unreasonable use more vigorously. Methods to achieve assurances remain under discussion. Depending on the methods chosen, amendments to existing statutes or execution of new agreements would be needed. Quantification of CALFED’s future water use efficiency program is discussed in Chapter 6.

Urban Water Use Forecasting

Urban water use forecasting relates future use to changes in factors influencing water use. Early forecasting methods were relatively simple and relied only on service area population to explain water use, assuming a direct relationship between population growth and applied water demand. These methods canprovide acceptable results over the short term, especially during periods of abundant water supply and steady economic growth. However, mid- to long-term forecast accuracy may decrease sharply due to changes in other variables influencing water use. Among these factors are changes in the ratio of single to multifamily dwellings, commercial and industrial growth, income, future water conservation actions, and water pricing. The price of water currently plays a small role in water use; it could become more important if water pricesincreased substantially. The water price elasticity section in Appendix 4A provides more detail on this subject. New urban water supplies will be relatively expensive, so understanding interactions between price and water use is important for forecasting urban use.As described in the appendix, the Department’s forecast used single family residential price elasticities of
-0.1 for winter months and -0.2 for summer months. The Department forecasted change in per capita water use in each hydrologic region to estimate 2020 urban applied water by hydrologic region. Variablesincluded population, income, economic activity, water price, and conservation measures (implementationof urban BMPs and changes to State and federal plumbing fixture standards). The general forecastingprocedure was to determine 1995 base per capita water use, estimate the effects of conservation measures and socioeconomic change on future use for 20 major representative water service areas in California, and calculate 2020 base per capita water use by hydrologic region from the results of service area forecasts. 1995 Base Per Capita Water Use. The 1995 base per capita water use includes water supplied by public water systems for municipal and industrial purposes and self-produced (not delivered by a water purveyor) surface water and groundwater. Per capita water use isnot the same as the applied water use shown in Bulletin 160 water budgets. Per capita use does not include recreation water use, energy production water use, and T

ABLE 4-5
1995 Urban Water Management Plans by
Hydrologic Region

Region Expected Filed

North Coast 13 10 San Francisco Bay 60 46
Central Coast 28 17 South Coast 187 152
Sacramento River 35 33 San Joaquin River 29 12 Tulare Lake 22 13 North Lahontan 5 2 South Lahontan 12 11 Colorado River 13 6
Total 404 3024-14 W

ATER U SE The California Water Plan Update B ULLETIN 160-98

T ABLE 4-6
Urban Water Use Study Input Variables

Water Use
Water use by sector, base year

Single family Multifamily
Commercial
Industrial Landscape
Seasonal water use, base year

Socioeconomic
Population, base year, and forecast year

Total population Population by dwelling type Persons per household by dwelling type Group quarters population Housing, base year, and forecast year

Number of housing units by dwelling type Growth rate of housing stock by dwelling type Employment, base year, and forecast year

Commercial
Industrial
Income, base year, and forecast year Water price, base year, and forecast year 

### losses from major conveyance facilities (the urban share of the “other” water demand category used in Bulletin 160-93). In most hydrologic regions, 1995 base per capita water use was calculated for each of theDepartment’s DAUs. In the South Lahontan and Colorado River regions, analyses were done at the PSA leveldue to the relatively sparse populations in those regions. The 1995 base per capita water use was computed
from normalized water use data to account for variation in annual weather patterns, water supply, and residual effects of the 1987-92 drought. Appendix 4C discusses the relationship between normalized data andactual urban water production data. Actual urban water use during 1995 was less than the Bulletin 160-98 base level in many areas, largely due to wet hydrologicconditions that decreased landscape irrigation requirements. (Likewise, urban water use during a dry yearwould likely exceed base year use due to higher landscape irrigation water use, assuming no constraints on water supplies). Base per capita 1995 water use was developed from historical water use during recent years with normal water supply and water use patterns. Data for years during and immediately following the drought
were removed from consideration due to the effects ofwater shortages of unprecedented severity and duration, mandatory and voluntary rationing programs, and a multi-year post-drought rebound in per capita water use on water use patterns. The 1995 base was computed from the 1990 per capita use in Bulletin 160-93, adjusted to account for permanent effects of urban BMPs and post-1990 changes to federal and State plumbing fixture standards. The most significant post-1990 change to the plumbing fixture standards
was that all toilets for sale or installation in Californiamust use no more than 1.6 gallons per flush, compared to 3.5 gallons or more per flush for older toilets. Plumbing code effects were quantified based on the proportion of total housing stock subject to the new code. ULFT retrofit water savings were estimated based on information on toilet retrofit programs from local water agencies. The final 1995 base value for each DAU was weighted by population to yield 1995 base per capita water use by hydrologic region. 2020 Per Capita Water Use Forecast. Forecasts for the urban water use study were based on three typesof input data: actual values of base year water and socioeconomic variables, forecasted values ofsocioeconomic variables for the year 2020, and savings assumptions for BMPs. Table 4-6 lists the input variables specified for each water service area. Table 4- 7 shows data sources for the study. The urban water use study estimated future changein per capita water use in 20 representative water service areas. (The results in Tables 4-8 and 4-9 display changes from 1990, rather than from the Bulletin’s1995 base year, to illustrate all effects of water conservation implementation, including the changes in plumbing fixture standards that began in 1992.) Theresults of the 20 individual model runs were extrapolated to forecast 2020 level per capita water use byhydrologic region (Tables 4-9 and 4-10). The difference between the 1995 and 2020 base levels reflectsthe influence of water conservation measures, socioeconomic change, and differential population growth on per capita water use in each region. The forecast results for the representative water service areas were expressed as a percent change in per capita use by 2020, and were averaged (weighted by service area population) to arrive at the percent changein per capita use by hydrologic region. For each region, the 2020 change was applied to the 1995 level per capita water use in each DAU to obtain 2020 per capita water use. The 2020 per capita water use then4-15 W ATER U SE The California Water Plan Update B ULLETIN 160-98

T

ABLE 4-7
Urban Water Use Study Data Sources

Water Use
Survey of Public Water System Statistics, DWR Urban water management plans Regional and local water agency reports on water use and conservation

Socioeconomic
Census of Population and Housing, U.S. Department of Commerce Survey of Current Business, USDC Statistical Abstract of the United States, USDC California Statistical Abstract, DOF California Population Characteristics, Center for Continuing Study of the California Economy Population Projections by Race and Ethnicity for California and its Counties 1990-2040, DOF Regional and local planning agencies

T ABLE 4-8
Model Study Results—Per Capita Water Use With Economic

Growth and Conservation Measures

Region Representative Water 1990 2020 Percent Change from 1990 Service Area (gpcd) (gpcd) Economic Conservation Effects Effects

North Coast City of Santa Rosa 156 136 -14 2

San Francisco Bay EBMUD 196 171 -16 3 Marin Municipal WD 153 136 -16 5 City and County of San Francisco 132 115 -16 3

Central Coast California Water Service Company, Salinas 153 132 -14 0 City of Santa Barbara 177 156 -15 4

South Coast City of Los Angeles 180 158 -16 4 City of San Bernardino 269 243 -11 1 San Diego County WA 196 176 -14 4

Sacramento River California Water Service Company, Chico 296 272 -10 2 City of Sacramento 290 263 -13 3

San Joaquin River California Water Service Company, Stockton 187 162 -12 -1 City of Merced 336 299 -10 0

Tulare Lake California Water Service Company, Visalia 273 235 -11 -3 City of Fresno 285 262 -10 2

North Lahontan South Lake Tahoe PUD 179 147 -15 -2

South Lahontan Indian Wells Valley WD 247 230 -10 3 Victor Valley County WD 340 322 -8 3

Colorado River City of Blythe 349 326 -11 4 City of El Centro 221 197 -13 24-16 W

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### was multiplied by the population forecast to compute 2020 urban applied water use for each DAU. The DAU-level results were aggregated and combined with minor components of urban use (conveyance losses, recreation water use, and energy production water use) to obtain total applied urban water demands.This method of computing future water use captures localized effects of differential population growth. The most significant example of variation in growth patterns is the relatively high growth rate in warmer,
drier inland areas of California where increased landscape irrigation requirements are reflected in higher per capita use values. Growth in inland areas tends topartially offset reductions in per capita use due to water conservation. Summary of Urban Water Use

Table 4-11 summarizes Bulletin 160-98 urbanapplied water use by hydrologic region. Statewide urban use at the 1995 base level is 8.8 maf in average water years and 9.0 maf in drought years. (Droughtyear demands are slightly higher because less precipitation is available to meet exterior urban water uses,such as landscape watering.) Forecasted 2020 use increases to 12.0 maf in average years and 12.4 maf in drought years. Full implementation of urban BMPs is estimated to result in demand reduction of 1.5 maf inaverage year water use by 2020. Without implementation of urban BMPs, average year use would have increased to 13.5 maf. Table 4-9 T

ABLE 4-9
2020 Change in Per Capita Use by Hydrologic Region—
Application of Model Results a

Region Economic Effects Conservation Effects % Change from 1990 % Change from 1990

North Coast 2 -14 San Francisco Bay 3 -16
Central Coast 2 -15 South Coast 4 -14

Sacramento River 3 -12 San Joaquin River -1 -12 Tulare Lake 1 -10 North Lahontan -2 -15 South Lahontan 3 -9 Colorado River 3 -12 Statewide 3 -15

a Model results applied to per capita use in each DAU.

T ABLE 4-10
Effects of Conservation on Per Capita Water Use a by Hydrologic Region
(gallons per capita per day)

Region 1995 2020

without conservation with conservation

North Coast 249 236 215 San Francisco Bay 192 188 166 Central Coast 179 188 166 South Coast 208 219 191
Sacramento River 286 286 264 San Joaquin River 310 307 274 Tulare Lake 298 302 268 North Lahontan 411 390 356 South Lahontan 282 294 268 Colorado River 564 626 535 Statewide 229 243 215

a Includes residential, commercial, industrial, and landscape use supplied by public water systems and self-produced surface and groundwater. Does not

include recreational use, energy production use, and losses from major conveyance facilities. These are normalized data.4-17 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### use. The table also illustrates that precipitation plays asmall role in meeting urban outdoor water needs (landscape water needs) in arid regions such as the Tulare Lake, South Lahontan, and Colorado River regions.

Agricultural Water Use The Department’s estimates of agricultural water use are derived by multiplying water use requirementsfor different crop types by their corresponding irrigated acreage, and summing the results to obtain atotal for irrigated crops in the State. This section begins by covering crop water use requirements, including demand reduction from water conservation programs. Irrigation efficiency and distribution uniformity are discussed in detail. A description of the process forforecasting irrigated acreage and factors affecting acreage forecasts follows. Forecasted 2020 agricultural water
demands are summarized at the end of the section.

Crop Water Use
The water requirement of a crop is directly related to the water lost through evapotranspiration. The amount of water that can be consumed through ET depends in the short term on local weather and in the long term on climatic conditions. Energy from solar radiation is the primary factor that determines the rate of crop ET. Also important are humidity, temperature,wind, stage of crop growth, and the size and aerodynamic roughness of the crop canopy. Irrigation frequency affects ET after planting and during early growth because evaporation increases when the soil All of the acreage amounts discussed in this chapter are irrigated acres, because estimates of irrigated acreage are needed to calculate agricultural water use. Crop production also occurs (to a much lesser extent) on non-irrigated lands. Dry-farmed grains are an example of crop production on non-irrigated lands. T ABLE 4-11
Applied Urban Water Use by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 169 177 201 212 San Francisco Bay 1,255 1,358 1,317 1,428
Central Coast 286 294 379 391 South Coast 4,340 4,382 5,519 5,612
Sacramento River 766 830 1,139 1,236 San Joaquin River 574 583 954 970 Tulare Lake 690 690 1,099 1,099 North Lahontan 39 40 50 51 South Lahontan 238 238 619 619
Colorado River 418 418 740 740 Total (rounded) 8,770 9,010 12,020 12,360



### As indicated in the Table 4-11, the South Coast and San Francisco Bay Hydrologic Regions together
amount to over half of the State’s total urban water4-18 W

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### surface is wet and is exposed to sunlight. Growing season ET varies significantly among crop types, depending primarily on how long the crop actively

grows. Direct measurement of crop ET requires costly investments in time and sophisticated equipment. There are more than 9 million acres of irrigated cropland in California, encompassing a wide range of climate, soils, and crops. Even where annual ET for two areas is similar, monthly totals may differ. For example, average annual ET for Central Coast interior valleys is similar to that in the Central Valley. Central Valley ET is lower than that in coastal valleys during the winterfog season and higher during the hot summers. Obtaining actual measurements for every combination ofenvironmental variables would be prohibitively difficult and expensive. A more practical approach is to estimate ET using methods based on correlation of measured ET with observed evaporation, temperature, and other climatologic conditions. Such methods can
be used to transfer the results of measured ET to other
areas with similar climates.The Department uses the ET/evaporation correlation method to estimate growing season ET. Concurrent with field measurement of ET rates, theDepartment developed a network of agroclimate stations to determine the relationship between measured ET rates and pan evaporation. D ata from agroclimatic studies show that water evaporation from a standard water surface (the Department uses the U.S. Weather Bureau Class A evaporation pan) closely correlates to crop ET. The ET/evaporation method estimates crop water use to
within ± 10 percent of measured seasonal ET. Crop coefficients are applied to pan evaporation data to estimate evapotranspiration rates for specific crops. (Crop coefficients vary by crop, stage of cropgrowth, planting and harvest dates, and growing season duration.) The resulting data, combined with
information on effective rainfall and water use efficiency, form the basis for calculating ETAW and applied water use. Crop applied water use includes theirrigation water required to meet crop ETAW and cultural water requirements. The amount of water applied to a given field for crop production is influenced by considerations such as crop water requirements, soil characteristics, theability of an irrigation system to distribute water uniformly on a given field, and irrigation managementpractices. In addition to ET, other crop water requirements can include water needed to leach soluble salts below the crop root zone, water that must be appliedfor frost protection or cooling, and water for seed germination. The amount required for these uses depends upon the crop, irrigation water quality, and weather
conditions. Part of a crop’s water requirements can be met by rainfall. The amount of rainfall beneficially used for crop production is called effective rainfall. Effective rainfall is stored in the soil and is available to satisfy crop ET or to offset water needed for special cultural practices such as leaching of salts. Irrigation providesthe remainder of the crop water requirement. Irrigation efficiency influences the amount of applied waterneeded, since a portion of each irrigation goes to system leaks and deep percolation of irrigation water below the crop root zone. There is a perception that only drip irrigation is an efficient agricultural water use technology. As described in Chapter 5, high efficiencies are possible with a variety of irrigation techniques. Considerations such as soil type, field configuration, and crop type influence the choice of

irrigation technique.4-19 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### The Bulletin’s 1995 base applied agricultural water use values were computed from normalized data to account for variation in annual weather patterns andwater supply. Normalizing entails applying crop coefficients to long-term average evaporative demand data. Actual applied crop water use during 1995 was less than the Bulletin 160-98 base in many areas due towet hydrologic conditions that increased effective rainfall, thus decreasing crop ETAW. Likewise, applied water use during a dry year (assuming no constraints on water supplies) would likely exceed the base due to less than average effective rainfall with an attendant increase in crop ETAW. For most hydrologic regions,1995 base applied water use was computed for the major crop types found in each of the Department’s DAUs. Analyses were done at the planning subarea
level in the South Lahontan and Colorado River Regions.Figure 4-5 shows ranges of 1995 base applied water and ETAW for some common California crops or crop types. ETAW represents a major depletion of water supply, and therefore is an important component ofstatewide and local water supply planning, groundwater modeling, and water transfer feasibility studies. Except in areas adjacent to the ocean, or areas where the groundwater or surface water is unacceptable for reapplication, irrigation water applied in excess of ET and cultural requirements (e.g., frost protection) is available to downstream users or to users pumping from groundwater. The purpose of the data presented in Figure 4-5 is to illustrate how great the range of applied water andETAW can be for a single crop or crop type in California. Climate and soil types are major factors that affectcrop water use. Other factors include farming practices, irrigation systems, and water availability. Crop water use is extremely site-specific, and no one valueof crop water use can be expected to represent a statewide condition.

Factors Influencing Agricultural Water Use
Irrigation Water Use Efficiency. Distributionuniformity is an important element in on-farm irrigation water use efficiencies. DU measures the variation in the amount of water applied to the soil throughout the irrigated area. Since no irrigation system is capable of applying and distributing water uniformly to all parts of a field, growers often apply enough water to meet crop water requirements of the driest part of the field to achieve optimum crop yields. Achieving a high DU requires excellent system design, maintenance, and management. Irrigation experts maintain that current hardware design and manufacturing technology limit the DU of most systems to 80 percent. As design and manufacturing technology advance and more refined manufacturing processes and hardware are developed, it may be possible to achieve DUs up to 90 percent.Chapter 5 describes the relationship of DU to irrigation efficiencies in more detail. Seasonal application efficiency is the sum of ETAW and cultural water requirements (such as for leaching salts below the root zone) divided by applied water.4-20 W

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### SAE is an appropriate index of water use efficiency for planning purposes, because it is based on the amount of water required to fully satisfy crop water needs while maintaining the favorable salt balance in the root zone required for long-term sustainability of agriculture. It differs from values of irrigation efficiency calculatedby growers to compare the amount of water beneficially used to the amount applied, because the amount beneficially used may be less than that needed to fully satisfy crop and cultural water requirements. Efficiencymeasures used by growers, such as DU and IE, are typically based on the average amount of water infiltrating the quarter of the field receiving the least water. These methods presume that one-half of the low quarter, or 12.5 percent of the field, is under-irrigated to some degree. The result is inadequate leaching and a reduction in crop yield in that part of the field. Values of SAE cannot be directly compared to IE values commonly cited in literature because they are based on different levels of irrigation effectiveness. Optimal SAE occurs when the driest part of the fieldreceives an amount of water equal to ETAW plus leaching water requirements, resulting in a 100 percenteffective irrigation. On the other hand, optimal IE occurs when the amount infiltrated in the low quarter equals ETAW plus leaching requirements, resulting in an 87.5 percent effective irrigation. (Since DU is also calculated based on the low-quarter method, optimal IE is equivalent to DU.) SAE is related to DU and to optimal IE by a linear function so that, for example, aDU of 75 percent implies an optimal SAE of 67 percent. The relationship among DU and optimal values
of IE and SAE is illustrated in Table 4-12. The maximum efficiency values achieved on-farm are generally less than shown due to conveyance losses, evaporation,
and uncollected surface runoff. Relationships between on-farm and regional efficiencies are complex. Often a portion of irrigation water applied to a field runs off the field or percolates into groundwater. Runoff and/or deep percolation from a given field may be considered a water loss to that particular field; nevertheless, this water is not lost to the system unless it goes directly to a nonreusable water source such as saline groundwater or to the ocean. If water quality is good, that water may be reapplied on a field or on other fields several times. Irrigation efficiency formulas developed for on-farm irrigation management cannot necessarily be applied to largerareas or regions. Numerical values of on-farm and regional efficiencies almost always differ. On-farm T

ABLE 4-12
Relationship Among Agricultural Water Use
Efficiency Measures

Distribution Irrigation Seasonal Application Uniformity Efficiency a Efficiency a

90 90 87
85 85 80
80 80 73 75 75 67
70 70 60

a Optimal values

Efficient Water Management Practices for Agricultural Water Suppliers in California List A—Generally Applicable EWMPs • Prepare and adopt a water management plan • Designate a water conservation coordinator • Support the availability of water management services

to water users • Improve communication and cooperation among water suppliers, water users, and other agencies • Evaluate the need, if any, for changes in institutional policies to which the water supplier is subject • Evaluate and improve efficiencies of the water supplier’s

pumps

List B—Conditionally Applicable EWMPs
• Facilitate alternative land use • Facilitate using available recycled water that otherwise would not be used beneficially, meets all health and safety criteria, and does not cause harm to crops or soil • Facilitate financing capital improvements for on-farm irrigation systems • Facilitate voluntary water transfers that do not unreasonably affect the water user, water supplier, the environment, or third parties • Line or pipe ditches and canals • Increase flexibility in water ordering by, and delivery to, water users within operational limits • Construct and operate water supplier spill and tailwater

recovery systems • Optimize conjunctive use of surface and groundwater
• Automate canal structures
List C—Other EWMPs • Water measurement and water use reporting • Pricing or other incentives4-21 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### efficiencies are usually lower than regional efficiencies due to reapplication of water in a region. A region canreach very high efficiencies as a result of a few reapplications, even if on-farm efficiencies are fairly low. Practices that encourage reapplication, such as tailwaterreturn and spill recovery systems, provide an opportunity to increase regional efficiency. Water reapplication can be the fastest and most economical way to boost regional efficiencies. Agricultural Water Conservation Programs. The amount of applied water saved depends on the actions of both water suppliers and irrigation water users.Achieving high on-farm water use efficiency is accomplished by optimizing many factors including management (such as irrigation scheduling), irrigation method, crop selection, and supply reliability. On-farm evaluations conducted by the Department and others show that irrigation management is more importantthan irrigation method in improving water use efficiency. (Chapter 5 describes common irrigation methods.)Bulletin 160-98 quantifies agricultural water conservation based on assumed statewide implementation of the 1996 agricultural MOU described in Chapter 2. The agricultural MOU provides a mechanism for planning and implementing EWMPs (see sidebar) that benefit water suppliers. The primary objective ofEWMPs is for suppliers to better serve farmers in order to facilitate improvements in on-farm practices.As of May 1998, 31 agricultural water agencies serving about 3 million acres of land had signed the MOU.Signatories to the MOU have committed to implement specified EWMPs, based on their evaluation of the benefits of each practice. EWMPs can lessen runoff and deep percolationof irrigation water, reducing the amount of water farmers must order from an irrigation district or pump from
their wells. Because the MOU is orientated to watersuppliers, it does not specify water use reduction factors and installation and/or compliance rates for farmirrigation system improvements. Therefore, the Department estimated water savings due to EWMPs based on their potential to remove impediments to optimal on-farm efficiency, expressed as increased SAE. SAE
resolves the interrelated effects of EWMPs and improved on-farm management into one variable that quantifies the net result of water conservation effortsby water suppliers and irrigation water users. It is expected that increasing use of EWMPs will yield more information on their water savings potential. Water savings due to agricultural water conservation were quantified for each DAU on the basis of expected improvements in SAE. It is assumed that by2020 SAE will reach 73 percent in all regions of California, averaged across crop types, farmland characteristics, and management practices. The DU of irrigation methods limits SAE. The average DU of irrigation systems in California is currently in the 70to 75 percent range, based on irrigation system evaluations conducted by the Department, resource conservation districts, water districts, and others. By2020, the average DU is expected to be about 80 percent. An irrigation method with a DU of 80 percentcan achieve a maximum SAE of about 73 percent, assuming that irrigation events are properly timed, thesoil is well drained, and none of the field is underirrigated.The Bulletin 160-98 forecast of conservation savings was calculated by comparing two scenarios of 2020 crop applied water demand under differing levels of SAE. First, crop applied water demand was computed based on the 2020 forecast of irrigated acreage and crop mix, but at existing (1995 base) levels of SAE foreach major crop category. Then SAE for each crop category was set to the 2020 forecast value and applied water demand was recomputed. Applied water savings
due to conservation were taken as the difference in applied water demand under the two scenarios.Table 4-13 shows that agricultural water conservation would reduce applied water demands by about 800 taf annually by 2020. Such reductions of applied water generally do not create new water supply; in most areas of California, excess irrigation water becomes available to other users. Even so, a reduction in ap- Table 4-13

T

ABLE 4-13
2020 Agricultural Water Use Reductions Due to

Conservation (taf)

Region Applied Water Depletion

North Coast 1 0 San Francisco Bay 1 0 Central Coast 82 0 South Coast 31 10
Sacramento River 203 0 San Joaquin River 148 2 Tulare Lake 45 1 North Lahontan 17 0 South Lahontan 20 10 Colorado River 249 210 Total 797 2334-22 W

ATER U SE The California Water Plan Update B ULLETIN 160-98



### plied water can serve other beneficial purposes such asreducing leaching of plant nutrients, reducing degradation of groundwater quality, and reducing agricultural drainage. Only practices that lessen evaporation from watersurfaces, reduce evapotranspiration, or diminish irrecoverable losses actually reduce depletions. Efficientwater management practices have relatively little effect on evaporation and ET. It is the location of water use, rather than the conservation measure employed,that is key to determining whether a reduction in irrigation water application translates into a depletion reduction. Agricultural lands adjacent to the ocean, orwhere the groundwater or surface water is unacceptable for reapplication, have the greatest potential forreducing depletions through efficient water management practices. In California, such agricultural lands are found in the South Coast Region, the west side ofthe San Joaquin Valley, and the Colorado River Region. Other water conservation planning requirements exist in addition to those in the agricultural MOU,most notably those applying to water agencies contracting with USBR. (CALFED’s proposed future water use efficiency program is discussed in Chapter␣ 6.) The Reclamation Reform Act of 1982 directed DOI to establish a water conservation planning program.In 1992, CVPIA established additional water conservation requirements for federal contractors receiving CVP supplies. USBR published criteria for CVPIA conservation plans and is reviewing the plans which contractors are required to submit. As of March 1998, more than 70 federal water contractors had submittedplans pursuant to CVPIA criteria. Discussions are underway with the agricultural council established by the 1996 MOU regarding developing a way for CVPIAplans to be accepted as plans complying with the agricultural MOU. CVPIA further requires that new, renewed, or amended CVP water service or repayment contracts mandate that surface water delivery systemshave water measurement devices or comparable methods of measuring water use. Agricultural Water Pricing. The relationship of agricultural water pricing to water use and the role ofpricing in achieving water conservation have been subjects of discussion in recent years. For water supplied by public agencies, the elected board members of thoseagencies ultimately have the responsibility for balancing desires to achieve demand reduction through water pricing with desires to provide affordable water rates to growers. For self-supplied agricultural water users, good business practices dictate maximizing water useefficiency, in terms of crop yield per unit of water applied. Agricultural water prices in California vary widely and are affected by factors such as geographiclocation and source of water supply. Appendix 4A provides background information on agricultural waterpricing. As described in the price elasticity information in the appendix, demand for irrigation water isgenerally price inelastic over the price ranges evaluated. There is no other commodity that can besubstituted for the water required to grow crops. Water costs are typically a relatively small percentage of the total cost of producing most crops.Crop markets, not water prices, generally dominate the economics of crop production. Bulletin 160-98 considers markets and other economic effects in the modeling performed to forecast future irrigated acreage, as described later in this chapter. When fully implemented, CVPIA tiered pricing requirements mayprovide new data on water price/water use relationships for CVP contractors, as described in the appendix.

Agricultural Acreage Forecasting
This section describes how 1995 base year irrigated acreage is established, and how that information is used to forecast 2020 irrigated acreage. Quantifying Present Irrigated Acreage. Forecasts of future agricultural acreage start with land use datathat characterize existing crop acreage. The Department has performed land use surveys since the 1950sto quantify acreage of irrigated land and corresponding crop types, and currently maps irrigated acreage in six to seven counties per year. The base data for landuse surveys is obtained from aerial photography or satellite imagery, which is superimposed on a cartographic base. Site visits are used to identify or verify crop types growing in the fields. From this information, mapsshowing locations and acreage of crop types are developed. Figure 4-6 is an example of a typical land use survey map, showing crop types in the Ceres 7.5 minute USGS quadrangle from the Department’s 1996 Stanislaus County survey.The Department’s land use surveys focus on quantifying irrigated agricultural acreage. Although fieldsof dry-farmed crops are mapped in the land use surveys, their acreage is not tabulated for calculating water use. In certain areas of the State, climate and market conditions are favorable for producing multiple cropsper year on the same field (for example, winter veg4-23 W ATER U SE The California Water Plan Update B ULLETIN 160-984-24 W

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### etables followed by a summer cotton crop). In these cases, annual irrigated acreage is counted as the sum of the acreage of the individual crop types. In the yearsbetween county land use surveys, the Department estimates crop types and acreage using data collected fromcounty agricultural commissioners, local water agencies, University of California Cooperative Extension Programs, and the California Department of Food and Agriculture. The starting point for determining Bulletin 160- 98 1995 base acreage was normalized 1990 irrigatedacreage from Bulletin 160-93. Changes in crop acreage between 1990 and 1995 were evaluated to determine if they were due to short-term causes (e.g., drought or abnormal spring rainfall), or if there wasan actual change in cropping patterns. Base year acreage was normalized to represent the acreage that would most likely be expected in the absence of weather andmarket related abnormalities. (More detail on the concept of normalizing base year data is presented in Chapter 3.) Figure 4-7 illustrates some general trends in California cropping patterns over time. Crop acreage by region for the normalized 1995 base is presented in Table 4-14. The 1995 base irrigated land acreage is about 9.1 million acres, which, when multiple cropped areas are tabulated, becomes a base irrigated cropped acreage of about 9.5 million acres. Forecasting Future Irrigated Acreage. The California’s Nursery Industry

When people think of irrigated agriculture, crops that often come to mind are commodities such as hay, grains, rice, row crops, and cotton. However, nursery products (flowers, plants, turf-grass) rank as the State’s fourth largest farm product in gross value, behind milk/cream, grapes, and cattle, and ahead of cotton, almonds, and hay, according to 1996 California Department of Food and Agriculture statistics. The prominence of the nursery industry reflects the extent of urbanization in California, as well as favorable climatic conditions.

California nursery products had a $1.6 billion farmgate value (wholesale value at the farm) in 1996. San Diego is the leading California county in nursery product valuation, followed by Santa Barbara, San Mateo, and Los Angeles Counties. California wholesale production represents about 26 percent of national nursery product sales. An important difference between the nursery industry and other agricultural sectors is the extent to which the industry’s revenues are tied to urban, as well as to agricultural, water supplies. Bulletin 160 treats nursery water use as an agricultural use. Many of the industry’s products, however,
are destined for urban and commercial locations where urban water supply availability influences landscaping choices and the market for nursery products.

About 25,000 acres are devoted to nursery products in California. Much of the acreage is in proximity to urbanized, coastal regions of the State near markets and major transportation routes.

The Central Valley produces most of California’s tomato crop. Much of the crop is used for processed tomato products, such as canned tomatoes and tomato sauces. Acreage devoted to truck crops like tomatoes is expected to increase in the future. 0 10 20 30 40 50 60 70 80

2020 1995 1970C r o p A c r e a g e , P e r c e n t o f S t a t e w i d e T o t a l Field Crops Trees & Vines Truck Crops General Trends in Cropping Patterns Over Time F IGURE 4-74-25 W ATER U SE The California Water Plan Update B ULLETIN 160-98TABLE4-14California Crop and Irrigated Acreage by Hydrologic Region, 1995 level(thousands of acres)Irrigated Crop NC SF CC SC SR SJ TL NL SL CR TotalGrain 72 2 26 11 270 180 260 7 2 70 900Rice0 0 0 0 494 22 0 1 0 0 517Cotton0 0 0 0 9 1851,026 0 0 24 1,244Sugar beets6 0 3 0 54 47 30 0 0 38 178Corn1 1 3 4 92 212 116 0 0 9 438Other field 3 1 16 4 155 120 97 0 1 70 467Alfalfa 53 0 21 10 149 231 296 44 34 256 1,094Pasture 122 5 18 20 352 199 49 107 18 43 933Tomatoes 0 0 10 7 138 82 111 0 0 9357Other truck23 11 382 87 56 130 19423 172 1,060Almond/pistachios0 0 0 0106 251 177 0 0 0534Other deciduous 76 183 219 154 191 0 3 1602Subtropical00 19 161 288 20200 37 455Grapes36 39 566 17 184 37800 20 736Total Crop Area 323 65 572 313 2,139 2,005 3,127 161 61 749 9,515Multiple Crop00 142 30 52 56 6300 104 447Irrigated Land Area 323 65 430 283 2,087 1,949 3,064 161 61 645 9,0684-26 W

ATER U SE The California Water Plan Update B ULLETIN 160-98

Table 4-14



### Department’s 2020 irrigated acreage forecast was derived from staff research, a crop market outlook study, and results from the Central Valley Production Model. As with any forecast of future conditions, there are uncertainties associated with each of these approaches. The Department’s integration of the results from three independent approaches is intended to represent a best estimate of future acreage, absent major changes from present conditions. It is important to emphasize that many factors affecting future cropped acreage are basedon national (federal Farm Bill programs) or international (world export markets) circumstances. California agricultural products compete with products from other regions in the global economy and are affected by trade policies and market conditions that reach far beyond the State’s boundaries. The Federal Agriculture Improvement and Reform Act of 1996, for example, affects agricultural markets nationwide, by changing federal price supports for specified agricultural commodities. Under the terms of that act, federal payments to growers will be reduced by 2002, and prior farm bill provisions that requiredgrowers to reduce planted acreages of regulated commodities are no longer in force. (Commodities with significant federal price support include wheat, feed grains, rice, cotton, dairy products, sugar, and peanuts.) The overall impact of the act to California may be lessthan its impact to states whose agriculture is less diversified and who are less active in export markets. In1994, for example, federal farm bill production payments to California growers represented about 1percent of California’s agricultural revenue. The potential impacts of FAIRA to California’s agricultural market are considered in Bulletin 160-98 by the crop market outlook study. Intrastate factors considered in making acreageforecasts included urban encroachment onto agricultural land and land retirement due to drainage problems (discussed in more detail in the followingsection). Urbanization on lands presently used for irrigated agriculture is a significant consideration in the South Coast Region and in the San Joaquin Valley, based on projected patterns of population growth. (See sidebar on water use impacts of land conversion.) DOF 2020 population forecasts, along with information gathered from local agency land use plans, were used Water Use Impacts from Urbanization of Agricultural Lands—A San Joaquin Valley Example

The Department projects a decline in California’s irrigated acreage by 2020, due in part to urbanization of agricultural
lands. Much of this urbanization will occur in the South Coast Region and in the San Joaquin Valley. Potential changes in water use resulting from land use conversion are often of concern to local agencies responsible for land use planning or for providing water supplies. Changes in water use must be evaluated on a site-specific basis, as the following example for the San Joaquin Valley illustrates.

Changes in water use depend on the kinds of crops grown and the density and type of urban development in an area. In the case of single-family dwellings, applied water use varies with housing density. Numerous studies have shown that dwellings on larger lots use more water per dwelling unit due to the larger landscaped areas. However, higher density developments have the greater applied water use per acre of land. A recent Department study of the Fresno area showed that applied water use of single-family dwellings and agricultural crops were similar at low housing densities (four or five units per acre). However, higher density single-family dwellings (six units or more per acre) that have become common in today’s new home construction market tended to have greater applied water requirements than some

crops. Growth in the Fresno area has caused expansion of urban development onto adjoining agricultural lands. Figure 4-8 is a plot of Department land use data illustrating the long-term expansion of urban development onto agricultural lands in the area. Department data show that average urban applied water use in the Fresno area (urban water use includes residential, commercial, and industrial purposes) is equivalent to about 3.2 af/acre. Typical agricultural applied water use for crops grown in the area is shown below. Actual agriculturalapplied water use for an individual crop will vary with fieldspecific conditions such as soil type and irrigation method.

Type of Use Applied Water Use (af/acre)

Urban 3.2 Agricultural Barley 1.3 Grapes 2.9
Cotton 3.2 Deciduous orchard 3.5 Pasture (improved) 4.5
Alfalfa 4.74-27 W ATER U SE The California Water Plan Update B ULLETIN 160-98

S a n J o a q u i n R i v e r E n t e r p

r i s e

C a n a l F r i a n t

- K e r n C a n a l

F r e s n o C a n a l

K i n g s R i v e r

Fowle r S

w itch Canal

S a n J o a q u i n R i v e r E n t e r p

r i s e

C a n a l F r i a n t

- K e r n C a n a l

F r e s n o C a n a l

K i n g s R i v e rFowle r S witch Canal Clovis

Fresno

Raisin City Fowler Sanger 180 99 41

41

41 99 180 180 168

145 Kerman

Raisin City Fowler Sanger 180 99 41

41

41 99 180 180 168

145

Kerman Fresno Clovis Changes in Land Use Over Time, DAU 233 F IGURE 4-8

1958 Urban

1994 Non-Urban4-28 W

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### to identify irrigated lands most likely to be affected by urbanization. Local water agencies and county farm advisors were interviewed to assess their perspective on land use changes affecting agricultural acreage. For example, urbanization may eliminate irrigated acreage in one area, but shift agricultural development onto lands presently used as non-irrigated pasture. Soil typesand landforms are important constraints in agricultural land development. If urbanization occurs onprime Central Valley farmland, some agricultural production may be able to shift to poorer quality soils on hilly lands adjoining the valley floor. A consequent shiftin crop types and irrigation practices would likely result—for example, from furrow-irrigated row crops to vineyards on drip irrigation. The Department’s crop market outlook, a form of Delphi analysis, was developed using information and expert opinions gathered from interviews with more than 130 University of California farm advisors, agricultural bankers, commodity marketing specialists,managers of cooperatives, and others. Three basic factors guided the CMO: current and future demand forfood and fiber by the world’s consumers; the share California could produce to meet this worldwide demand;and technical factors, such as crop yields, pasture carrying capacities, and livestock feed conversion ratios that affect demand for agricultural products. (Milk anddairy products are California’s largest agricultural product, in terms of gross value. The demand for these products is reflected in the markets for alfalfa, grains, and other fodder used by dairies.) The CMO forecastsa statewide crop mix and estimates corresponding irrigated acreage. The major findings of the CMO for year 2020 were that grain and field crop acreage would decrease, while acreage of truck crops and permanent crops would increase. The Central Valley Production Model is a mathematical programming model that simulates farming decisions by growers. Inputs include detailed information about production practices and costs as well as water availability and cost by source. The modelalso uses information on the relationship between production levels of individual crops and crop market prices. The model’s geographic coverage is limited to the Central Valley, which represents about 80 percent of the State’s irrigated agricultural acreage. The CVPM results also indicated future crop shifting, from grains and field crops to vegetables, trees, and vines. TheCVPM forecast showed a small reduction in crop acreage from 1995 to 2020. Other Factors Affecting Forecasted Irrigated Acreage. The process of estimating future irrigatedacreage considered statewide factors such as crop markets and urban expansion onto agricultural lands. The Department considered an additional region-specificfactor, the long-standing agricultural drainage management issues on the west side of the San Joaquin Valley. Drainage management issues in this area have a dual focus—salt management to permit continued agricultural production on lands requiring drainage systems, and trace minerals management (principallyselenium) to limit adverse water quality and environmental impacts. The need for drainage systems to permit farming in some westside areas was recognized concurrently with the development of irrigated agriculture in theregion. USBR’s San Luis Drain, for example, was originally planned to convey drainage water out of the valley
to the Delta. The drain was instead terminated at Kesterson Reservoir, where waterfowl mortalities led to discovery of elevated selenium levels in the early1980s. The drain was subsequently closed. (A discussion of trial reopening of part of the drain for the Grasslands Bypass Channel Project is provided in Chapter 8.) Post-Kesterson studies of valley drainageproblems have sought to quantify factors such as extent of areas with shallow depths to groundwater, tributary areas in Coast Range sediments from whichtrace minerals are derived, and water quality characteristics of drain water and shallow groundwater. The 1990 report of the interagency San Joaquin Valley Drainage Program projected that as much as 460,000 acres of irrigated land would be taken out ofproduction by the year 2020 if the report’s recommendations were not implemented. The reportrecommended retirement of 75,000 acres of land having the worst drainage problems by 2040. The Bulletin 160-98 year 2020 acreage forecast follows the same procedure used in Bulletin 160-93 and assumes that the 75,000 acres would be retired at an average rate of 1,500 acres per year. Thus, 45,000 acres of land wouldbe retired between 1990 and 2020. USBR’s 1997 request for proposals for the CVPIA land retirement program (described in Chapter 6) elicited offers to sell 31,000 acres of drainage-impaired lands, suggesting that the assumed 45,000 acres of land retirement could occur by 2020. Data from the Department’s monitoring program for groundwater levels in the San Joaquin Valley are shown in Figure 4-9. Agricultural acreage with a water4-29 W ATER U SE The California Water Plan Update B ULLETIN 160-98

Stockton Sacramento

Bakersfield Modesto

Santa Barbara Fresno F IGURE 4-9 Areas of Shallow Groundwater in the San Joaquin Valley

0 - 5 Feet

5 - 10 Feet

10 - 15 Feet

15 - 20 Feet Depth to Free Water (Spring 1997 Data)

CALIFORNIA NEVADA

SAN JOAQUIN

HYDROLOGIC REGION

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HYDROLOGIC REGION

P

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ATER U SE The California Water Plan Update B ULLETIN 160-98



### table within 10 feet of the surface increased from 1,061,000 acres in 1991 to 1,262,000 acres in 1997. Agricultural lands with a water table within 5 feet of the surface increased from 311,000 acres in 1991 to743,000 acres in 1997. Increases in the extent of shallow groundwater coincide with the end of drought conditions and above-average rainfall. (TheDepartment’s monitoring program is limited to measurement of groundwater levels. There has been noregion-wide monitoring of selenium and other constituents in shallow groundwater since the 1987 work performed for the 1990 report.)To implement recommendations of the 1990 report, four State agencies (DWR, SWRCB, DFG, and DFA) and four federal agencies (USBR, USFWS, USGS, and Natural Resource Conservation Service) signed a 1991 MOU to participate in a cooperative interagency program. The program was to address the management plan’s eight major recommendations: source control, drainage reuse, evaporation ponds, landretirement, groundwater management, limiting discharge to the San Joaquin River, and institutional change. (The plan’s recommendations did not address disposal of drain water outside of the Central Valley.)Significant progress has been made on some recommendations. Some examples of drainage management activities are described in Chapters 7-9. In 1997, the interagency drainage program drafted

Factors that influence the conversion of irrigated lands to urban
use include the lands’ proximity to existing
urban areas and

transportation corridors, and local agency land use planning and zoning policies. Agroforestry Research

Agroforestry is being tested for managing drainage impaired lands. Agroforestry systems integrate trees and shrubs into cropping activities to produce marketable products and/or provide resource conservation. Agroforestry principles could be applied to on-farm water management, where increasingly saline water would be applied to successively more salt-tolerant plants to reduce drainage volumes. For example, drainagewater from salt-sensitive crops could be used to irrigate a salttolerant crop like cotton. Drainage water from the cotton would then be used to irrigate salt-tolerant trees, such as eucalyptus. Drainage water from the trees would be reused again to irrigate highly salt-tolerant plants such as saltgrass. Finally, the drainage water would be discharged into a solar evaporator. This is an experimental program. To be commercially successful, markets would need to be found for the eucalyptus trees and other biomass produced. In 1985 a cooperative effort among several growers and agencies began at a 27-acre site near Mendota. A second research project of
622 acres was established at Red Rock Ranch in Fresno County in 1993, and a third research project was started by Tulare Lake Basin Drainage District.4-31 W ATER U SE The California Water Plan Update B ULLETIN 160-98

Alfalfa and Market Conditions

The market for California alfalfa is closely tied to the State’s dairy industry. California is the nation’s leading dairy state. According to DFA’s 1996 statistics, milk/cream production amounted to $3.7 billion, making it the State’s top-valued agricultural commodity. California, with about 1.3 million dairy cows and over 2,300 dairy farms, accounted for almost 17 percent of the nation’s dairy production in 1996. Leading dairy counties are Tulare, San Bernardino, Merced, Stanislaus,
and Riverside.

Alfalfa supports the dairy and livestock industries (including the recreational horse industry) and also provides about one-third of the nation’s honey production. In-state alfalfa production does not meet all of the demand within
California. Alfalfa is trucked from the intermountain states to Central California dairies. Although some alfalfa is exported from California (mostly to Japan), imports into California have exceeded exports by 1 to 8 percent over the past several years.

California milk/cream production has increased more than 50 percent in the past 12 years. About half of this increase is due to increases in milk yield per cow and the remainder is
due to increased numbers of cows. This has created a continuing demand for alfalfa. Most dairy rations in California contain some component of alfalfa. Relatively little raw milk flows into or out of the State. California’s dairy industry is based on in-state production and processing capacity. The demand for milk products is greatest in the State’s major population centers — the San Francisco Bay Area and urbanized Southern California. Dairy production has been concentrated in the San Joaquin Valley and in the Inland Empire region of Southern California, within convenient distances of major markets. Increasing urbanization of formerly agricultural lands in Southern California is shifting more dairy production to the southern San Joaquin Valley. To supply feed to these dairies, the San Joaquin Valley has become the largest production area for alfalfa in the State, producing nearly half of California’s alfalfa.

According to DFA, California’s Grade A milk production can be broken down into the following categories:

Cheese 36% Butter & nonfat dry milk 29% Fluid milk products 24% Frozen dairy products 6% Soft products 5%

### an activity plan to update the report’s recommendations with new information. The activity plan isscheduled for completion in 1999. Source control objectives of the 1990 report have been achieved orexceeded over large areas. In the first year of Grasslands Bypass Channel Project implementation(described in Chapter 8), irrigation and drainage modifications by Grasslands area farmers reduced seleniumdischarges to the San Joaquin River. Tiered water pricing has been implemented in the drainage problem area of the Grasslands subarea. Three agroforestry drainage reuse research projects have been implemented (see sidebar).One factor not included in Bulletin 160-98 irrigated acreage forecasts is the potential large-scale conversion of agricultural land to wildlife habitat forreasons other than the westside drainage problems described above. The CALFED program represents thelargest pending example of potential conversion of irrigated agricultural lands to habitat, as described in CALFED’s March 1998 draft programmatic EIR/EIS and supporting documents. CALFED’s potential land
conversion amounts have not been included in the Bulletin 160-98 irrigated acreage forecast because they are preliminary at this time (a site-specific environmental document with an implementation schedule for land conversion has not yet been prepared), and because CALFED’s preliminary numbers are so large relativeto the Bulletin’s market-based forecast of irrigated acreage that they would negate the results of the forecast. Overall, CALFED program activities as presently planned could convert up to 290,000 irrigated acres to habitat and other uses, an amount almost as greatas the 325,000 acre reduction in irrigated acreage forecast in the Bulletin. Water use implications of large-scale land conversions are not included in theBulletin 160-98 forecast. Impacts of such land conversions are expected to be addressed in the next water plan update, when CALFED’s program may be better
defined.The difficulty in estimating impacts from largescale land conversion programs stems from the domino effect that changes in acreage in one location have on acreage and crop types in other areas, and how crop markets determine which crop shifts are feasible. For example, CALFED’s preliminary reports suggest that up to 190,000 irrigated acres in the Delta could be converted to other land uses. This amount representsabout 40 percent of Delta irrigated acreage, where principal crops are corn, alfalfa, tomatoes, grain, orchard4-32 W

ATER U SE The California Water Plan Update B ULLETIN 160-98TABLE4-15California Crop and Irrigated Acreage by Hydrologic Region, 2020 Level(thousands of acres)Irrigated Crop NC SF CC SC SR SJ TL NL SL CR TotalGrain 66 1 21 5 249 152 201 8 0 97 800Rice0 0 0 0 484 15 0 1 0 0 500Cotton0 0 0 0 15 171 888 0 0 461,120Sugar beets6 0 2 052 18 13 0 029 120Corn2 0 3 290 188 101 1 0 3390Other field31 141 154 139 11000 33 455Alfalfa620 206 147 181 238 50 24 217 945Pasture1235 166 316 165 26 103 18 32 810Tomatoes0 0 8 4141 93 130 0 014 390Other truck28 11 373 43 79 197 30021 231 1,265Almond/pistachios0 0 0 0127 270 198 0 0 0595Other Deciduous 76 203 234 153 199 0 2 1625Subtropical00 18 117 33 10 21500 32 425Grapes38 41 753 29 183 36600 15 750Total Crop Area 335 65 570 190 2,150 1,935 2,985 165 45 750 9,190Multiple Crop00 150 10 70 80 10000 145 555Irrigated Land Area 335 65 420 180 2,080 1,855 2,885 165 45 605 8,6354-33 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### crops, and truck crops (e.g., asparagus). Some land conversion in the Delta might result in production on new agricultural lands—most likely, rolling hills on the edge of the valley floor which are suitable for only limited crop types (orchards and vineyards). Some of the land conversion might result in increased demand in other areas for the affected crops, such as increased demand for asparagus from the Imperial and Salinas Valleys. Results of 2020 Acreage Forecast. Table 4-15 shows the 2020 irrigated acreage forecast. The total irrigated crop acreage is forecasted to decline by 325,000 acres from 1995 to 2020, primarily in the San Joaquin Valley and South Coast areas. Reductionsin crop acreage are due to urban encroachment, drainage problems in the westside San Joaquin Valley, and amore competitive economic market for California agT

ABLE 4-16
Applied Agricultural Water Use by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 894 973 927 1,011 San Francisco Bay 98 108 98 108 Central Coast 1,192 1,279 1,127 1,223 South Coast 784 820 462 484

Sacramento River 8,065 9,054 7,939 8,822 San Joaquin River 7,027 7,244 6,450 6,719
Tulare Lake 10,736 10,026 10,123 9,532 North Lahontan 530 584 536 594
South Lahontan 332 332 257 257 Colorado River 4,118 4,118 3,583 3,583 Total (rounded) 33,780 34,540 31,500 32,330

### ricultural products. Pasture and field crops are forecasted to decline by about 631,000 acres. Truck crops and permanent crops are forecasted to increase by about 238,000 and 68,000 acres, respectively. Acreage with multiple cropping is forecasted to increase by 108,000 acres, reflecting the expected increased production of truck crops. These statewide findings are usedin developing the forecasted agricultural water demands.

Summary of Agricultural Water Use
Crop water use information and irrigated acreage data are combined to generate the 2020 agricultural water use by hydrologic region shown in Table 4-16. As previously noted, the 2020 forecasted values take into account EWMP implementation, which results in a 2020 applied water reduction of about 800 taf. pumpkin photo The proximity of California agriculture to densely populated urban markets encourages the production of specialty crops. Pumpkin patches and Christmas tree lots are examples of specialized urban niche
markets.4-34 W

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### Environmental Water Use

Bulletin 160-98 defines environmental water as
the sum of:
• Dedicated flows in State and federal wild and

scenic rivers • Instream flow requirements established by water right permits, DFG agreements, court actions, or
other administrative documents • Bay-Delta outflows required by SWRCB • Applied water demands of managed freshwater
wildlife areas This definition recognizes that certain quantities of water have been set aside or otherwise managed forenvironmental purposes, and that these quantities cannot be put to use for other purposes in the locations
where the water has been reserved or otherwise managed. This definition also recognizes that these uses of environmental water can be quantified. Unlike urbanand agricultural water use, much of this environmental water use is brought about by legislative or regulatory processes. Certainly the environment uses more water than is encompassed in this definition—
the rainfall that sustains the forests of the Sierra Nevada and the North Coast, the winter runoff that supportsflora and fauna in numerous small streams, the shallow groundwater that supports riparian vegetation in some ephemeral streams—but the Bulletin’s definitioncaptures uses of water that are managed (in one fashion or another) and quantifiable. As described earlier, average annual statewide precipitation over California’s land surface amounts to about 200 maf. About 65 percent of this precipitation is consumed through evaporation and transpiration by the State’s forests, grasslands, and other vegetation. The remaining 35 percent comprises the State’s average annual runoff ofabout 71 maf. The environmental water demands discussed in this section are demands that would be met through a designated portion of that average annual
runoff. The following discussion covers factors affecting the four categories of environmental water use. As with urban and agricultural water use, options for meeting
future environmental water needs—such as federal acquisition and transfer of water to meet CVPIA AFRP goals—are covered in Chapter 6 and in the regionalwater management chapters. The environmental water use categories below are discussed in order of size—from greatest (wild and scenic rivers) to smallest (wildlife refuges). Environmental water use is shown on an applied water basis. Flows in Wild and Scenic RiversFlows in wild and scenic rivers constitute the largest environmental water use in the State. Figure 4-10is a map of California’s State and federal wild and scenic rivers. The 1968 National Wild and Scenic Rivers Act, codified to preserve the free-flowing characteristics ofrivers having outstanding natural resources values, prohibited federal agencies from constructing, authorizing, or funding the construction of water resources projects having a direct or adverse effect on the values for which the river was designated. (This restriction also appliesto rivers designated for potential addition to the national wild and scenic rivers system.) There are twomethods for having a river segment added to the federal system—congressional legislation, or a state’spetition to the Secretary of the Interior for federal designation of a river already protected under state statutes. No new federal designations have been made since publication of Bulletin 160-93. A number of river systems within lands managed by federal agencies are being studied as candidates. Forexample, U.S. Forest Service draft environmental documentation in 1994 and 1996 recommended designation of 5 streams (129 river miles) in Tahoe
National Forest and 160 river miles in Stanislaus National Forest. These waterways drain to the Central Valley where their flows are used for other purposes, and wild and scenic designation would not affect the existing downstream uses. The California Wild and Scenic Rivers Act of 1972prohibited construction of any dam, reservoir, diversion, or other water impoundment on a designatedriver. As shown on Figure 4-10, some rivers are included in both federal and State systems. No new State designations have been made since Bulletin 160-93, although the Mill and Deer Creeks Protection Act of 1995 (Section 5093.70 of the Public Resources Code) gave portions of these streams special status similar towild and scenic designation, by restricting construction of dams, reservoirs, diversions or other water impoundments. Tables 4-17 and 4-18 show the wild and scenic river flows used in Bulletin 160-98 water budgets by waterway and by hydrologic region. The flows shownare based on the rivers’ unimpaired flow. (The unimpaired flow in a river is the flow measured or calculated at some specific location that would be unaffected bystream diversions, storage, imports or exports, and return flows.) For the average year condition, the4-35 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### Redding Federal and State Designation

State Designation Only

Federal Designation Only F IGURE 4-10

California Wild and Scenic Rivers

E. Fork Carson River

W. Walker River

Kings River Eel River S. Fork Van S. Fork

Trinity Smith River

K l a m a t h

R i v e r

D

u z e n R

i v e r

M

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A m e r i c a n

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A

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i v e r

M

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i v e r

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M

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S

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S

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i v e r4-36 W

ATER U SE The California Water Plan Update B ULLETIN 160-98

T

ABLE 4-18
Wild and Scenic River Flows by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 17,800 7,900 17,800 7,900 San Francisco Bay 0 0 0 0 Central Coast 98 28 98 28 South Coast 69 51 69 51
Sacramento River 1,733 736 1,733 736 San Joaquin River 1,974 939 1,974 939 Tulare Lake 1,614 751 1,614 751 North Lahontan 271 154 271 154
South Lahontan 0 0 0 0 Colorado River 0 0 0 0 Total (rounded) 23,560 10,560 23,560 10,560 T

ABLE 4-17
Wild and Scenic River Flows by Waterway (taf)

1995 2020
Waterway Average Drought Average Drought

Klamath 9,070 3,980 9,070 3,980 Smith 2,920 1,720 2,920 1,720 Eel 5,810 2,200 5,810 2,200 Big Sur 83 22 83 22 Sisquoc 15 6 15 6 Sespe Creek 69 51 69 51 Middle Fork Feather 1,129 497 1,129 497
North Fork American 584 239 584 239
Lower American 20 0 20 0 Tuolumne 1,192 572 1,192 572 Merced 782 367 782 367 Kings 896 448 896 448
North Fork Kern 628 275 628 275 South Fork Kern 90 28 90 28 East Fork Carson 71 34 71 34
West Walker 200 120 200 120 Total (rounded) 23,560 10,560 23,560 10,560



### long-term unimpaired flow from the Department’s Bulletin 1 was used. The estimated average unimpaired flow for the 1990-91 water years was used for the drought condition.

Instream Flows

Instream flow is the water maintained in a stream or river for instream beneficial uses such as fisheries, wildlife, aesthetics, recreation, and navigation. Instream flow is a major factor influencing the productivity and diversity of California’s rivers and streams. Instream flows may be established in a variety of ways—by agreements executed between DFG and a water agency, by terms and conditions in a water right permit from SWRCB, by terms and conditions in a FERC hydropower license, by a court order, or by an agreement among interested parties. Required flows on most rivers vary by month and year type, with wet year requirements generally being higher than dry year requirements. Converting from net water use budgets used in prior editions of Bulletin 160 to the appliedwater budgets used in Bulletin 160-98 created a challenge in properly accounting for multiple instreamflows within a river basin. Bulletin 160-98 used a simplified approach in which only the largest downstream flow requirement was included in the water budgets.4-37 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### This simplified approach undercounts applied instreamflow requirements on streams having multiple requirements. The Department is developing a new modeling approach for the next water plan update that will more accurately quantify applied instream flows. Since the determination of 1990-level instream
flow values used as base conditions in Bulletin 160- 93, subsequent agreements or decisions have increased or added instream flow requirements for the Trinity River, Mokelumne River, Stanislaus River, Tuolumne River, Owens River, Putah Creek, and Mono Lake tributaries. In addition, ten new waterways have beenadded to the Bulletin 160-98 instream flow water budgets—the Mad River, Eel River, Russian River, Truckee River, East Walker River, Nacimiento River, San Joaquin River (at Vernalis), Walker Creek, Lagunitas Creek, and Piru Creek. The sidebar on American River
environmental water use illustrates how environmental water demands are treated in Bulletin 160 water budgets. Factors Affecting Future Instream Flows. It isdifficult to forecast future regulatory actions or agreements that could change existing instream flow requirements. Bulletin 160-98 thus does not attemptto quantify the outcome of future regulatory or administrative actions. Factors likely to affect future flow requirements include listings or potential listings ofnew fish species, habitat restoration programs, and programs to acquire water for environmental purposes. Recent decisions on federal listing of coho salmonand steelhead trout (see Chapter 2) are likely to influence water management decisions affecting these species, but the specific actions will ultimately dependon the outcome of consultations, biological assessments, biological opinions, and habitat conservationplans. In 1997, the Governor’s Executive Order W159-97 created the Watershed Protection and
Restoration Council. The council oversees State watershed protection and enhancement activities, including restoration of anadromous fish. One goal of this effort is to provide sufficient protection to coho, steelhead, and other anadromous salmonids to satisfy ESA requirements. Successful implementation of thisprogram could lessen water supply impacts of salmonid listings.
Coho salmon are found in coastal streams and in large river systems such as the Klamath River and itstributaries. Some of the greatest potential for new water supply impacts could be on the Klamath River system (including its Trinity River tributary), where USFWS is finalizing instream flow studies for several salmonids. Steelhead populations are distributed Part of Sespe Creek is
included in the wild and scenic river system. The creek, located in Ventura County, is tributary to the Santa
Clara River.4-38 W

ATER U SE The California Water Plan Update B ULLETIN 160-98



### throughout coastal streams and rivers, and are alsofound in the Sacramento Valley. (Wild stocks of steelhead in the Sacramento River system are mostlyconfined to upper watershed tributaries such as Antelope, Deer, and Mill Creeks, and the Yuba River. TheSan Joaquin River system no longer supports a significant natural steelhead population—most steelhead found in the system are hatchery fish.) Data from the SWP and CVP pumping plants in the southern Delta indicate that most juvenile steelhead move through theDelta during the winter and early spring, when BayDelta Accord restrictions are already in place. Water supply impacts on coastal rivers and streams must be evaluated from a basin-specific standpoint. The spring-run chinook salmon traditionally spawned in upper reaches of Central Valley rivers and their tributaries. Today, Deer, Mill, and Butte Creeks
are considered crucial Sacramento River tributaries forspring-run spawning. Sustaining populations of springrun are also found in Battle Creek, and the Feather and Yuba Rivers, although there are questions about the genetic integrity of these populations because of interbreeding between fall-run and spring-run salmon.Portions of Deer and Mill Creeks have been given special status by State legislation to help protect the fishery. As described in Chapters 5 and 6, many habitat restoration programs are underway and substantialfunding is available for restoration actions. Improvements such as facilitating fish passage, replenishing spawning gravel, and restoring shaded riverine habitat will help in efficient management of water used for environmental purposes. Specific benefits of habitat
restoration will have to be evaluated on a watershedby-watershed basis—it is not possible to quantifypotential water supply implications of present and future habitat restoration actions at a statewide level. Examples of programs or projects now underway are described in later chapters. The 1997 draft programmatic EIS for CVPIAimplementation describes federal water acquisition alternatives for the AFRP. Table 4-19 shows the amounts proposed in alternative 4 of the draft PEIS. These flowsrepresent the high end of potential federal water acquisition actions. Under USBR’s assumptions for alternative 4, the instream flows are not allowed to be exported at the Delta. Quantification of alternative 4 flows was provided by PROSIM operations studies. The federal agencies’ ability to acquire the water would be subject to their finding willing sellers. In addition to water acquisition on major rivers

Environmental Water Use—An American River Example

As discussed in Chapter 3, the return flow from one water use can become the supply for the next downstream use. The applied water budgets in Bulletin 160-98 reflect the multiple uses which supplies in a river basin may have. Reapplication of flows in the American River for environmental purposes provides an illustration of how the Bulletin accounts for multiple uses in its water budgets.

The American River originates in the Sierra Nevada, flowing generally from east to west down through the foothills into the Sacramento Valley, ultimately reaching the Sacramento River and the Delta. The upper watershed of the American River consists of the north, middle and south forks. The mainstem, or Lower American River, begins near Folsom
at the confluence of the north and south forks. Environmental water supplies are reapplied at several locations between the upper watershed and the Delta.

Wild and scenic environmental water demands exist on the American River’s north fork (584 taf) and mainstem (20 taf). In Bulletin 160-98 water budgets, American River wild
and scenic flows are classified as environmental water use on the demand side of the budget and as required environmental instream flow on the supply side of the budget. These environmental demands are not consumptive; hence, the surface supplies are available for downstream use.

The American River has several instream flow requirements on its three forks as well as on its mainstem. For example, a 54 taf (75 cfs) requirement exists below Ralston Afterbay Dam on the middle fork and a 72 taf (100 cfs) requirement exists below Chili Bar Dam on the south fork. The river’s largest instream flow requirement is on the mainstem below Nimbus Dam. This 234 taf requirement is the only American River instream flow requirement accounted for in the water budgets. As with wild and scenic demands, the American River instream flow requirement is shown as environmental water use on the demand side of the budget and as required environmental instream flow on the supply side of the budget. This environmental demand is not consumptive; therefore, the surface supply is available for downstream use.

Required instream flow in the American River is reapplied downstream to meet Delta outflow requirements. The Bulletin 160-98 water budgets classify this flow as reapplied surface water supply. About 70 percent of the Delta’s 5.6 maf environmental demand (4.0 maf) is satisfied through reapplication of water released to meet environmental instream requirements in rivers tributary to the Delta.4-39 W ATER U SE The California Water Plan Update B ULLETIN 160-98

T

ABLE 4-19
Proposed Instream Flows, CVPIA PEIS Alternative 4 (taf)

Location Region Target Average

Merced River San Joaquin River 200 194
Tuolumne River San Joaquin River 200 197 Stanislaus River San Joaquin River 200 194
Calaveras River San Joaquin River 30 27 Mokelumne River San Joaquin River 70 62
Yuba River Sacramento River 100 87 Total 800 761



### for the Alternative 4 instream flows shown in the table, the draft PEIS also proposes water acquisition on smaller Sacramento River tributaries such as Deer, Mill, and Battle Creeks. The draft PEIS does not quantifytarget flows and acquisitions for these smaller tributaries. The public comment period on the draft CVPIA PEIS closed in April 1998 and USBR and USFWSexpect to release a final PEIS in 1999, after the publication date of this Bulletin. CVPIA authorizes DOI to acquire supplemental water from willing sellers. At this time, no long-term sources (e.g., long-term contracts for water transfers)have been established—water acquired has been purchased on a year-to-year basis. It is not possible to identify specifically how and where the supplemental water would be obtained in the future, or what other water demands might be reduced as a result of CVPIA water transfers. Chapter 6 provides more detail on how water marketing arrangements are treated in Bulletin 160 water budgets.As discussed in Chapter 2, CVPIA also affects Trinity River instream flows, by requiring that Trinity River flows be maintained at not less than 340 taf/yr while USFWS conducts an instream flow study that was to be completed by 1996. USFWS’s preliminary results suggest that instream flows of 592 taf/yr (weighted average of five water year types) may be proposed.USBR, USFWS, Trinity County, and the Hoopa Valley Tribe are preparing an EIR/EIS to evaluate impacts of the proposed flows. A draft EIR/EIS has not yet been released. Bulletin 160-98 uses the existing instream flow requirement of 340 taf/yr since a formal proposal for new Trinity River instream flows has not yet been released. Instream Flow Summary. Tables 4-20 and 4-21 show instream flows used in Bulletin 160-98 water budgets by waterway and by hydrologic region. The drought year scenario shown in the tables represents the minimum annual required flow volume. For average water years, the annual required flow volume is computed by combining the expected number of years in each year type (wet, above normal, normal, belownormal, and/or dry, as specified in the existing agreement or order). In water budget computations, the Departmentcounts instream flows as depleted if the flows go directly to a salt sink, such as the ocean. In the Central Valley where some instream flows may reach the ocean,any depletions are counted toward required Delta outflow (see following section). This approach avoids counting depletions twice—once as instream flow and
once as Delta outflow.

Bay-Delta Outflow
Environmental water use for Bay-Delta outflow is computed by using operations studies to quantify SWRCB Order WR 95-6 requirements. This sectionbriefly describes the Delta’s setting and some of its environmental resource issues. Readers interested indetailed descriptions of Delta hydrodynamics, facilities, and environmental resources may wish to review the extensive materials prepared by the Interagency Ecological Program, San Francisco Estuary Program, or CALFED program. Setting. The Bay-Delta has two high tides and two low tides every day. An enormous volume of water (anaverage of about one-fourth of the estuary’s total volume), moves in and out of the estuary with each tidalcycle. Tidal action and Delta outflow are two important physical processes which establish salinity gradients and carry sediments through the system. Tidal action and Delta outflow cause seaward-flowing fresh water from the rivers to mix with denser landward-flowing salt water from the ocean. The average tidal flow rate in the Delta is about 170,000 cfs, much greater than the average seaward flow of fresh water from rivers and

streams.4-40 W

ATER U SE The California Water Plan Update B ULLETIN 160-98

Fish species covered by the CVPIA’s doubling goal are salmon, steelhead, striped bass, sturgeon, and American shad. This sturgeon was photographed at the Steinhart Aquarium. CVPIA Anadromous Fish Restoration Program

One provision of CVPIA directed DOI to develop (by October 1995) and to implement a program “which makes all reasonable efforts to ensure that, by the year 2002, natural production of anadromous fish in Central Valley rivers and streams will be sustainable, on a long-term basis, at levels not less than twice the average levels attained during the period of 1967-1991”. (The San Joaquin River between Friant Dam and Mendota Pool is not covered by this goal.) In response to this provision, USFWS prepared a 1995 working paper listing many potential restoration actions (some involving instream flows, and some not) without regard to their reasonableness. Elements of that working paper were subsequently incorporated into a revised draft restoration plan prepared in May 1997. One function of the draft plan was to evaluate (at a programmatic level) the reasonableness of implementing potential restoration actions, given the authority and funding provided DOI by CVPIA. (For example, a potential restoration action that would involve modifying the diversion works of a local water agency would only be reasonable if the local agency wished to participate with USBR or USFWS in the action.) The revised draft plan is scheduled to be followed by an implementation plan that would review priority actions to be taken in the next three to five years.

The CVPIA tools available to USFWS and USBR to carry out the AFRP include the 800 taf of project water dedicated for environmental purposes, the authority to acquire supplemental water to achieve AFRP goals, and the many physical habitat restoration measures required in the act (e.g., restoring spawning gravel, screening diversions, improving fish passage at Red Bluff Diversion Dam). The CVP dedicatedwater is only available to USFWS and USBR on CVPcontrolled rivers below the major project dams. For other Central Valley waterways, the agencies are proposing to carry out a water acquisition program to buy water to meet AFRP needs. The quantity of water to be acquired is subject to available federal funding and the availability of water on the market. USBR’s 1997 draft CVPIA PEIS illustrates costs and impacts associated with different levels of supplemental water acquisition.4-41 W ATER U SE The California Water Plan Update B ULLETIN 160-98

T

ABLE 4-21
Instream Flow Requirements by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 1,410 1,285 1,410 1,285 San Francisco Bay 17 9 17 9 Central Coast 20 9 20 9 South Coast 4 4 4 4

Sacramento River 3,397 2,784 3,397 2,784 San Joaquin River 1,169 712 1,169 712 Tulare Lake 0 0 0 0 North Lahontan 85 84 85 84
South Lahontan 107 81 107 81 Colorado River 0 0 0 0 Total (rounded) 6,210 4,970 6,210 4,970 T

ABLE 4-20
Instream Flow Requirements by Waterway (taf) a

1995 2020

River or Creek Average Drought Average Drought

Klamath 833 833 833 833 Trinity 341 341 341 341
Mad 46 46 46 46
Eel 49 15 49 15
Russian 142 51 142 51 Lagunitas Creek 10 9 10 9 Walker Creek 6 0 6 0 Carmel 4 2 4 2
Nacimiento 16 7 16 7 Piru Creek 4 4 4 4
Clear Creek 25 25 25 25 Cache Creek 7 7 7 7 Putah Creek 22 22 22 22
Sacramento 1,945 1,702 1,945 1,702 Feather 880 588 880 588 Yuba 274 196 274 196

Bear 10 10 10 10
American 234 234 234 234
Mokelumne 158 84 158 84
Stanislaus 187 158 187 158 Tuolumne 214 94 214 94
Merced 79 67 79 67 San Joaquin 532 309 532 309 Truckee 70 70 70 70 East Walker 15 15 15 15 Mono tributaries 82 56 82 56
Owens 25 25 25 25 Total (rounded) 6,210 4,970 6,210 4,970

a On streams with multiple instream requirements, only the largest downstream requirement is included in Bulletin 160-98 water budgets.4-42 W

ATER U SE The California Water Plan Update B ULLETIN 160-98

Recovery Efforts for Winter-Run Chinook Salmon

As indicated by the plot of winter-run salmon escapement, there has been a long-term decline in the species’ population. The ultimate goal for recovery of winter-run salmon would be restoration of a self-sustaining, naturally spawning population. Two efforts being conducted to help achieve this goal are a captive broodstock program and an artificial propagation program. The purpose of the broodstock program is to maintain the genetic composition of the existing population, and that of the artificial propagation program is to stabilize and increase the naturally spawning population.

Discussions among State and federal agencies and stakeholder groups in 1991 and 1992 led to creation of a program to evaluate the feasibility of rearing Sacramento River winter-run fry in captivity, so that a broodstock would be available if wild winter-run fish were to disappear. (The population’s small size makes it vulnerable to catastrophic loss of a year class, such as a loss that could be caused by a chemical spill in the vicinity of winter-run spawning areas. The captive broodstock would provide an alternative source of genetic material as insurance against such a loss.) Agencies participating in funding the program include USBR, USFWS, NOAA, the Department, and DFG. Rearing facilities were established at the University of California’s Bodega Marine Laboratory and the California Academy of Sciences’ Steinhart Aquarium. Juvenile fish, beginning with the 1991 year class, were delivered to the facilities in 1992. The parent broodstock were wild winter-run captured in the Sacramento River. Presently, fish from four year classes are being held at the
facilities.

The artificial propagation program entails trapping known wild adult winter-run fish, spawning them in a controlled environment, and rearing the offspring for release back to the river system. As adults, the artificially propagated fish would return to winter-run spawning areas and commingle with wild winter-run. Artificial propagation activities were originally begun at USFWS’s Coleman National Fish Hatchery on Battle Creek, but fish reared at Coleman imprinted on Battle Creek water and returned there to spawn, rather than going to the upper Sacramento River as desired. (There were also difficulties associated with distinguishing between winter-run and spring-run chinook, in selecting the fish to be propagated. Better genetic identification techniques have been developed to address this problem.)

The most recent development in the artificial propagation program was construction of an interim rearing facility, the Livingston Stone National Fish Hatchery, on the mainstem Sacramento River immediately downstream from ShastaDam. This facility will allow the artificially spawned winterrun salmon to imprint on mainstem Sacramento River water, so that they will return to natural spawning grounds on the mainstem as adults. Water supply for the hatchery is provided via piping from the dam’s penstocks. The hatchery is beginning operations in 1998.

Additional efforts to help recover winter-run chinook salmon, such as screening diversions and habitat improvement projects, are described in Chapter 8. CVPIA directed USFWS to rehabilitate and expand Coleman National Fish Hatchery. The hatchery was constructed in 1942 to mitigate loss of Sacramento River salmon spawning areas due to construction of Shasta and
Keswick Dams.

0 20 40 60 80 100 120

1995 1990 1985 1980 1975 1970 Winter-Run Salmon EscapementE s c a p e m e n t i n T h o u s a n d s4-43 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### Three major components of Delta inflow include precipitation, inflow from the Sacramento and SanJoaquin Rivers, and inflow from east side streams (including the Calaveras, Mokelumne and Cosumnes Rivers). Figure 4-11 shows annual inflow and outflowvalues for 1980-96. For this period, the average annual inflow to the Delta was 25.7 maf, more than 75 percent of which was contributed by the Sacramento and San Joaquin Rivers.
Delta outflow is the calculated amount of water flowing past Chipps Island at the western edge of theDelta into Suisun Bay. The magnitude of Delta outflow controls salt water intrusion from the ocean intothe estuary. The magnitude of Delta outflow also influences the distribution of many estuarine fishes and invertebrates. Generally, the greater the outflow, the
farther downstream estuarine fish and invertebrates occur. The relationship between Delta outflow and
abundance of fish and invertebrates is much less clear. Some species, such as longfin smelt and juvenile splittail, show strong correlations between abundance and Delta outflow. The effects of outflow on species can vary depending on the time of year volume of
outflow. Suisun Bay, the first bay below the Delta, receives fresh water inflow that contributes dissolved nutrients needed to support estuarine food chains. Adjacent to Suisun Bay is Suisun Marsh, which includes about 58,600 acres of diked managed wetlands, tidal marsh, and adjacent grasslands, 29,500 acres of waterways, and a buffer zone of 27,900 acres of varying land use.Suisun Marsh is one of the largest contiguous brackish water marshes in the United States. Nearly half of the waterfowl and shorebirds migrating on the Pacific flyway pass through the Bay-Delta each year, using the Suisun marsh and other Delta wetlands as feeding and resting stations. Fresh water outflow from the Delta passes throughSuisun Bay and through the Carquinez Straits, entering San Pablo Bay, and eventually reaching the GoldenGate. By comparison, there is limited fresh water outflow and tidal circulation at the southern end of San Francisco Bay. Fresh water outflow to the South Bay comes from local tributaries such as Coyote Creek and the Guadalupe River. San Pablo Bay and the SouthBay both offer shallow water habitat. National wildlife refuges—the San Pablo Bay NWR and the San Francisco Bay NWR—occupy parts of the shoreline in these areas. See Figure 4-12 for a location map of the Bay-Delta.

0 10 20 30 40 50 60 70 80

1995 1990 1985 1980 Annual Delta Inflow and Outflow 1980-96 F IGURE 4-11F l o w i n m a f Inflow Outflow a

a 1983 was the wettest year in Northern California in this century.4-44 W

ATER U SE The California Water Plan Update B ULLETIN 160-98

North Bay Aqueduct

River Sacramento

San Aqueduct Joaquin

River

Delta-Mendota Canal Lodi River Sacramento

San Francisco San Pablo

Bay el

Clifton Court Forebay mne Aqueduct

California Aqueduct

South TracyPumping Plant P a c i f i c
O

c e a n Banks Pumping Plant

S a n F r a n c i s c o B a y

Hetch Hetchy Aqueduct uct Rio Vista Fairfield

Vallejo Vacaville

Costa Canal

Bay umne Mok

San Jose Barker Slough Pumping Plant

Suisun Bay Honker Bay

Contra Grizzly Bay el umne Mok F IGURE 4-12

Bay-Delta Estuary

Coyote Creek Guad

alupe Calaveras River

Stockton

River Moke lu

Pilarcitos Lake San Andreas Lake

Crystal Springs Reservoir Aqued mnes River Cosu

Twitchell Island

Sherman Island Chipps Island Suisun Marsh4-45 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### Delta Fish Species of Special Concern. About two-thirds of California’s salmon migrate through the Delta, including species having commercial importance(fall-run chinook salmon), as well as listed or candidate species (winter-run chinook, spring-run chinook, and steelhead trout). Resident fish species of specialconcern include Delta smelt (listed as threatened under both the State and federal ESAs) and splittail (proposed for federal ESA listing). Habitat needs ofanadromous and resident Delta species of special concern were reflected in actions taken in the Bay-Delta Accord and in SWRCB’s Order WR 95-6. The accord’sprovisions for coordination of CVP and SWP operations in the Delta with the presence of fish species ofconcern have been reflected in actions by the CALFED Operations Group to reduce Delta exports attimes when monitoring indicated that significant numbers of certain fish species were present in the southern Delta. Day-to-day management of CVP and SWPDelta operations under near real-time conditions requires extensive data collection and monitoringsupport. The Interagency Ecological Program, a cooperative effort of nine State and federal agencies (DWR, DFG, SWRCB, USBR, USFWS, EPA,NMFS, USACE, and USGS), acquires and disseminates near real-time fish distribution and abundance The Delta is characterized by miles of meandering waterways and leveed islands used mainly for agricultural purposes.

Delta smelt, native to the Bay-Delta, have a one year life span and relatively low reproductive rate, making their population

abundance sensitive to
short-term habitat changes.4-46 W

ATER U SE The California Water Plan Update B ULLETIN 160-98



### data used by the CALFED Operations Group. Populations of native species of special concern are affected by a variety of factors, many of which are
not related to Delta outflow. One nonflow factor nowreceiving more attention is competition from introduced aquatic species (see Chapter 2 for a descriptionof the National Invasive Species Act of 1996). Introduction of non-native species into an ecosystem canalter the pre-existing balance achieved among the native species. Native species’ populations can be reduced, for example, when introduced species out-compete the native species for food or otherwise alter the food chain, or when introduced species prey upon native species.In the Bay-Delta, new introductions are occurring in a system that already has numerous introduced species. Researchers estimate that the Bay-Delta is nowhome to at least 150 introduced plant and animal species, some of which were introduced deliberately (planting of game fish species such as striped bass) andothers whose arrival was accidental (discharge of invertebrates in ship ballast water). The Asian clam, for example, was first detected in the Bay in 1986 and has
now become the most abundant mollusk in the northern part of the Bay. This clam is a voracious feeder onthe phytoplankton which supports other aquatic species. The zebra mussel—which has caused millions of dollars of damage in the Great Lakes states—has not yet been detected in the Delta, but experts believe thatit may be only a matter of time before the mussel arrives. Invasive plant species in the Delta include Egeria densa and Arundo Donax(giant reed). Hydrilla, another well-known invasive aquatic plant, is now found in Clear Lake in Northern California, and controlmeasures are being taken to eradicate it there, to prevent its spread to Delta waterways. Quantifying Delta Outflow Requirements.SWRCB Order WR 95-6 established numerical objectives for salinity, river flows, export limits, and Delta outflow. DWRSIM operations studies were used to translate these numerical objectives into Delta outflow requirements for average and drought year scenarios.The studies computed outflow requirements of approximately 5.6 maf in average years and 4.0 maf in drought years.

Wetlands

The wetlands component of environmental wateruse is based on water use at freshwater managed wetlands, such as federal national wildlife refuges and State wildlife management areas. The following text reviewsthe status of wetland acreage in California and wetland management programs, then discussesquantification of water demands and supplies for wetlands. In general, wetlands can be divided into saltwater and brackish water marshes (usually located in coastal areas) and freshwater wetlands (generally located ininland areas). Five areas of California contain the largest remaining wetlands acreage in the State—the Central Valley, Humboldt Bay, San Francisco Bay, Suisun Marsh, and Klamath Basin. The majority of the State’s wetland protection and restoration effortsare occurring in these areas. Nontidal wetlands usually depend on a supplemental water supply, and protecting or restoring them may create demands for freshwater supplies. Wetlands Policies and Programs. Many programs and policies have been adopted by federal, State and regional agencies and private entities to protect and
restore wetlands in California. Several of the more reThe Asian clam was first detected in the San Francisco Bay in 1986. By the early 1990s, it was the most abundant mollusk in the northern part of the Bay. Much of the land in the Suisun Marsh is owned and managed by private gun clubs for duck hunting. DFG manages a wildlife area on Grizzly Island.4-47 W ATER U SE The California Water Plan Update B ULLETIN 160-98

California is a wintertime destination for migratory waterfowl on the Pacific flyway. Managed wetlands provide feeding, resting, and overwintering sites for the waterfowl.



### cent wetland programs and policies are discussed below. Ecosystem restoration is a large part of the CALFED program. CALFED’s draft ERP plan proposes habitat restoration goals that include creating 64,000 acres of seasonal and perennial wetlands and 2,000 acres of riparian habitat, returning 37,000 to 57,000 acres to tidal action and enhancing 8,000 acres of existingseasonal wetlands. About 1,700 acres of wetland restoration projects were funded under the accord’s Category III program in 1995 and 1996. CVPIA required DOI to provide water supplies
to the wetlands areas shown in Table 4-22. The Sacramento Valley refuges were to be provided with water supplies specified in a 1989 refuge water supply investigation prepared by USBR, and the San Joaquin Valley wetlands areas with supplies specified in USBR’s San Joaquin Basin Action Plan/Kesterson Mitigation Action Plan. This water supply was to be provided intwo increments—the first corresponding to the existCalifornia Wetlands Conservation Policy

In 1993, a California wetlands conservation policy was established. The goals of the policy were to establish a framework and a strategy that would: • Ensure no overall net loss and achieve a long-term net gain

in the quantity, quality, and permanence of wetlands acreage and values in California in a manner that fosters creativity, stewardship, and respect for private property. • Reduce procedural complexity in the administration of

State and federal wetlands conservation programs. • Encourage partnerships to make landowner incentive programs and cooperative planning efforts the primary
focus of wetlands conservation and restoration. The policy recommended completion of a statewide inventory of wetlands which would lead to the establishment of a formal wetland acreage goal. This inventory is in progress. The Resources Agency expects these policies to result in improved status for 30 to 50 percent of the State’s wetlands by the year 2010. Based on an estimate of 450,000 acres of existing wetlands in the State, as much as 225,000 acres of wetland could be improved, restored or protected.4-48 W

ATER U SE The California Water Plan Update B ULLETIN 160-98



### ing average annual deliveries that the wetlands had been receiving from drain water and other sources, and the second corresponding to the ultimate or optimummanagement levels of the wetlands. The first increment of water supply (Level 2) was to be provided by reallocation of CVP supplies. The second increment (Level 4) was to be acquired through purchases from willing sellers. DOI was to acquire all of the second increment of supply by 2002. USBR has operated the CVP to provide the Level 2 supplies, and has been making year-to-year short-term water purchases for the increments of Level 4 supply. USBR and USFWS havebeen studying conveyance alternatives (and groundwater extraction, in addition to surface water supply alternatives) associated with making these increased supplies available to the refuges. CVPIA also required DOI to prepare a report by September 1997 to investigate methods of improvingwater supplies in the Central Valley for existing private wetlands and for 120,000 acres of new wetlands.The 120,000 acres came from wetland restoration objectives of a Central Valley Habitat Joint Venture report. USFWS’s report is currently in preparation. Additionally, the act required that financial
incentives be made available to farmers within the CVP service area for flooding agricultural lands to provide waterfowl habitat. The incentives include cost-sharingfor water purchases, pumping costs, facility construction (e.g., water control structures), and upgrades or maintenance to existing facilities. CVPIA caps the funding for this program at $2 million per year and the program terminates in 2002.In 1986, the North American Waterfowl Management Plan was signed by the United States and Canada. The plan was updated in 1996 and Mexico became asignatory. NAWMP provides a framework for waterfowl management in North America through 2010; it includes numerical goals for waterfowl populations and for habitat protection, restoration, and enhancement. Implementing NAWMP is the responsibility of joint ventures in which governmental agencies and private organizations pool resources to address habitat needs. T

ABLE 4-22
CVPIA Refuge Water Supplies a (taf)

Refuge Level 2 Supply at Level 4 Supply at Refuge Boundary Refuge Boundary
Sacramento Valley Refuges

Sacramento National Wildlife Refuge 46.4 50.0 Delevan National Wildlife Refuge 20.9 30.0 Colusa National Wildlife Refuge 25.0 25.0 Sutter National Wildlife Refuge 23.5 30.0 Gray Lodge Wildlife Management Area 35.4 44.0 Total for Sacramento Valley Refuges 151.2 179.0 San Joaquin Valley Refuges

San Luis National Wildlife Refuge 19.0 19.0 Kesterson National Wildlife Refuge b 10.0 10.0 Volta Wildlife Management Area 13.0 16.0 Los Banos Wildlife Management Area 16.6 25.5 San Joaquin Basin Action Lands

Freitas 5.3 5.3 West Gallo 10.8 10.8 Salt Slough 6.7 10.0 China Island 7.0 10.5 Grasslands Resource Conservation District 125.0 180.0 Mendota Wildlife Management Area 27.6 29.7 Merced National Wildlife Refuge 15.0 16.0

East Gallo 8.9 13.3 Kern National Wildlife Refuge 9.9 25.0 Pixley National Wildlife Refuge 1.3 6.0 Total for San Joaquin Valley Refuges 276.1 377.1 Total for all Refuges 427.3 556.1

a Table is excerpted from 1997 draft CVPIA PEIS.

b Kesterson NWR was merged with San Luis NWR subsequent to CVPIA enactment.4-49 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### There are four NAWMP joint ventures covering parts of California. A fifth joint venture is being consideredin Southern California. The four existing joint ventures are described below.The Central Valley Habitat Joint Venture, established in 1988, was the first California joint venture. CVHJV adopted six goals for the Central Valley: • Protect 80,000 acres of wetlands through fee acquisition or conservation easement. • Restore (and protect) 120,000 acres of former
wetlands. • Enhance 291,555 acres of existing wetlands. • Enhance water-based habitat on 443,000 acres of private agricultural land. • Secure 402,450 af of water for 15 refuges in the Central Valley. • Secure CVP preference power for public and private lands dedicated to wetland management (i.e., provide access to low-cost power generated at CVP facilities). In 1990, the Legislature authorized the Inland Wetlands Conservation Program administered by the Wildlife Conservation Board. This program carries outsome CVHJV objectives by administering a $2 million per year program to acquire wetland habitat. The Pacific Coast Joint Venture encompasses coastal wetlands, major rivers, and adjacent uplands from northern British Columbia to the northern edgeof San Francisco Bay. In California, there are two focus areas with strategic plans outlining specific target areas and acreage objectives. Almost all the wetlandsare coastal projects with little or no freshwater requirements. Objectives for the northern focus area (Del Norte and Humboldt counties) are:• Maintain 22,000 acres of seasonal wet pasture in agricultural usage compatible with water-associated
wildlife. • Permanently protect an additional 10,500 acres of key wetlands through easements or fee acquisitions. • Protect, restore, and enhance 10,100 acres of wetlands on existing public lands. • Assist landowners to protect, enhance, and restore 5,000 acres through cooperative projects. Objectives of the southern focus area (Mendocino, Sonoma, and Marin Counties excepting watersheds draining to San Francisco Bay) are:• Permanently secure through fee acquisition or easements an additional 20,000 acres of coastal and interior wetlands, riparian habitats, and associated uplands. • Restore 3,500 acres of reclaimed coastal and interior wetlands on private and public lands. • Enhance 5,500 acres of coastal and interior wetlands and riparian habitats on public and private lands. Approximately half of the acreage in the southern focus area is inland (nontidal) habitat requiring fresh

water.The Intermountain West Joint Venture encompasses parts of Canada and Mexico and all or part of eleven western states, including eastern California. TheCalifornia action group has completed a working agreement and drafted plans for six focus areas. Acreage goals for acquisition, restoration, and enhancement have not
been established.The San Francisco Bay Joint Venture was established in 1995. Its management board is drafting an implementation strategy. Formal acreage goals and timelines for acquisition and restoration projects will be established. It is expected that many of the areas protected or restored by the SFBJV will be tidal areas with little or no fresh water requirement. Refuge Water Supply Conservation Programs. In the spring of 1997, a refuge water supply interagencycoordinated program task force was formed as an outgrowth of discussions in CALFED and CVPIA programs regarding the need to have best management practices for water conservation on wildlife refuges. The goal of the task force is to develop a commonmethodology for water management planning, including water conservation actions, for the federal, State, and private refuges covered in CVPIA’s refuge water supply provisions. A draft document containing BMPsor efficient water use guidelines for the refuges is scheduled to be released for public review in 1998.
Wetlands Water Use. Bulletin 160-98 quantifiesapplied water needs only for managed wetlands, because other wetlands types such as vernal pools or coastal wetlands use naturally-occurring water supply (precipitation or tidal action). Managed wetlands are defined for the Bulletin as impounded freshwater and nontidal brackish water wetlands. Managed wetlandsmay be State and federal wildlife areas or refuges, private wetland preserves owned by nonprofit organizations, private duck clubs, or privately owned agricultural lands flooded for cultural practices such as rice straw decomposition. Figure 4-13 showsCalifornia’s publicly owned wetlands. Some of the largest concentrations of privately owned wetlands are the
duck clubs in the Suisun Marsh and the flooded rice fields in the Sacramento Valley. (Acreage of rice fieldsflooded to enhance decomposition of stubble remaining after harvest and to provide habitat for4-50 W

ATER U SE The California Water Plan Update B ULLETIN 160-98

N.W.R. = National Wildlife Refuge

W.A. = Wildlife Area Publicly-Owned Fresh Water Wetlands F IGURE 4-13

Shasta Valley W.A. Butte Valley W.A.
Lower Klamath N.W.R.
Tule Lake N.W.R.
Clear Lake N.W.R.
Modoc N.W.R.
Ash Creek W.A.
Willow Creek W.A. Honey Lake W.A. Upper Butte Basin W.A.

Sacramento River N.W.R.

Sacramento N.W.R.
Delevan N.W.R. Gray Lodge W.A.
Butte Sink N.W.R.
Colusa N.W.R. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16 17
18
19
20
21
22
23
24
25
26
27
28
29
30
31 Sutter N.W.R. Yolo Bypass W.A.
Stone Lakes N.W.R. Grizzly Island W.A.
North Grasslands W.A.

San Luis N.W.R.
Merced N.W.R.
Volta W.A.

Los Banos W.A.
Mendota W.A. Pixley N.W.R.

Kern N.W.R. San Jacinto W.A. Imperial W.A.
Salton Sea N.W.R. 10 11

13 12

15 16 17

18

19

20

21 22

23 24 25

26

27

28

29

30 31 14 1 2 3 4 5

6

7

8
94-51 W ATER U SE The California Water Plan Update B ULLETIN 160-98



### overwintering waterfowl was identified by Department land use surveys.) State and federal wetlands in the Central Valleyare normally managed to support several types of wildlife use areas—permanent marsh, seasonal marsh, irrigated waterfowl food crops (such as millet, rice, orsmartweed), and non-irrigated uplands. Each has different applied water requirements, as indicated in
Table 4-23, which shows typical ranges for CentralValley wetlands. Table 4-24 shows wetlands water demands by region.

T ABLE 4-23
Ranges of Applied Water on Central Valley
Managed Wetlands (af/acre/year)

Type of Use Applied Water

Permanent marsh 5-10 Seasonal marsh 2-10 Irrigated waterfowl food crops 1-4 

### Summary of Environmental Water Use

Table 4-25 shows base 1995 and forecasted 2020 environmental water use by hydrologic region. The large values in the North Coast Region illustrate the magnitude of demands for wild and scenic rivers in comparison to other environmental water demands.

Water Use Summary by Hydrologic Region

Tables 4-26 and 4-27 summarize California applied water use by hydrologic region. The tables combine the urban, agricultural, and environmental water use described in this chapter. These demands, together with the water supply information presented in Chapter 3, are used to prepare the statewide water balance shown at the beginning of Chapter 6 and the regional water balances shown in Chapters 7-9.

T

ABLE 4-25
Applied Environmental Water Use by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 19,544 9,518 19,545 9,518 San Francisco Bay 5,762 4,294 5,762 4,294
Central Coast 118 37 118 37 South Coast 100 82 104 86
Sacramento River 5,833 4,223 5,839 4,225 San Joaquin River 3,396 1,904 3,411 1,919 Tulare Lake 1,672 809 1,676 813 North Lahontan 374 256 374 256
South Lahontan 107 81 107 81 Colorado River 39 38 44 43 Total (rounded) 36,940 21,240 36,980 21,270 T

ABLE 4-24
Wetlands Water Use by Hydrologic Region (taf)

1995 2020 Region Average Drought Average Drought

North Coast 325 325 325 325 San Francisco Bay 160 160 160 160
Central Coast 0 0 0 0 South Coast 27 27 31 31
Sacramento River 632 632 632 632 San Joaquin River 230 230 240 240
Tulare Lake 50 50 53 53 North Lahontan 18 18 18 18 South Lahontan 0 0 0 0 Colorado River 39 38 44 43 Total (rounded) 1,480 1,480 1,500 1,5004-52 W

ATER U SE The California Water Plan Update B ULLETIN 160-98TABLE4-27California Drought Year Water Use by Hydrologic Region (taf)19952020Region Urban Agricultural Environmental Total Urban Agricultural Environmental Total(rounded)(rounded)North Coast1779739,51810,6702121,0119,51810,740San Francisco Bay 1,3581084,2945,7601,4281084,2945,830Central Coast2941,279371,6103911,223371,650South Coast4,382820825,2805,612484866,180Sacramento River 8309,0544,22314,1101,2368,8224,22514,280San Joaquin River 5837,2441,9049,7309706,7191,9199,610Tulare Lake69010,02680911,5301,0999,53281311,440North Lahontan4058425688051594256900South Lahontan2383328165061925781960Colorado River4184,118384,5707403,583434,370Total (rounded) 9,01034,54021,24064,79012,36032,33021,27065,960TABLE4-26California Average Year Water Use by Hydrologic Region (taf)19952020Region Urban Agricultural Environmental Total Urban Agricultural Environmental Total(rounded)(rounded)North Coast16989419,54420,61020192719,54520,670San Francisco Bay 1,255985,7627,1101,317985,7627,180Central Coast2861,1921181,6003791,1271181,620South Coast4,3407841005,2205,5194621046,080Sacramento River 7668,0655,83314,6601,1397,9395,83914,920San Joaquin River 5747,0273,39611,0009546,4503,41110,820Tulare Lake69010,7361,67213,1001,09910,1231,67612,900North Lahontan3953037494050536374960South Lahontan238332107680619257107980Colorado River4184,118394,5707403,583444,370Total (rounded) 8,77033,78036,94079,49012,02031,50036,98080,5004-53 W ATER U SE The California Water Plan Update B ULLETIN 160-984A-1 A PPENDIX 4A The California Water Plan Update B ULLETIN 160-98 Appendix 4A



### This appendix is provided as background to respond to interest expressed by Bulletin 160-98 reviewers in water pricing information. Water prices in California vary widely, as discussed below. The more than 2,800 local agencies in California that providewater service establish their prices based on factors specific to their individual service areas, and those prices are generally reviewed by agencies’ elected or appointed boards of directors, or by the California Public Utility Commission. Public agencies are not permitted to make a profit from their water sales, and the profits that privately owned water purveyors are allowed to make are established by the PUC. Water Retail PricingMany factors influence the prices charged by water agencies. For public water agencies, the types of charges they may levy depend upon the legislation under which they were created. Table 4A-1 shows types of California water supply agencies. Descriptions of the general powers of the public agencies shown in thetable can be found in DWR’s Bulletin 155-94, General Comparison of Water District Acts.Investor-owned utilities’ water rates are set by the California Public Utilities Commission. Privately owned mutual water companies set rates for their members.

T

ABLE 4A-1
Types of Local Supply Water Agencies in California a

Type Ownership Number

County Service Area Public 880 Mutual Water Company Private 801 Community Services District Public 309 Investor-Owned Water Utility Private 195 County Water District Public 178
Water District Public 157 Irrigation District Public 97 Public Utility District Public 52 Flood Control and Water Conservation District Public 41 County Water Works District Public 40 Municipal Water District Public 40 Water Agency or Water Authority Public 31
Water Conservation District Public 13 Water Storage District Public 8 Municipal Utility District Public 5 Water Replenishment District Public 2 Metropolitan Water District Public 1 Total 2,850

a Water supply may also be provided by local agencies having other purposes (e.g., reclamation districts).
Source: Department of Health Services and State Controller’s Office data, 1994-96. 

# Urban and Agricultural Water Pricing 

# 4A4A-2 A

PPENDIX 4A The California Water Plan Update B ULLETIN 160-98 Appendix 4A



### Acquisition and Delivery CostsAcquisition costs are costs associated with obtaining water from a source. These costs may vary greatly from one source to another. Some water agencies have developed their own supply sources, some purchase water wholesale from larger agencies, and some have a mix of their own supplies plus wholesale purchases. Other costs include transportation and local delivery charges and water treatment costs. Supplies delivered for urban use require treatment, which is becoming an increasingly greater component of total cost as more stringent drinking water quality regulations are put into place. Compliance with surface water filtration andinformation collection requirements of the Safe Drinking Water Act, for example, is a substantial cost item for many water agencies.Some water agencies use water rates to fully recover the costs of acquiring, treating, and delivering supplies, others use a combination of water rates and local property taxes. Another important considerationis whether a water agency sets its rates to reflect shortterm or long-term costs. This is significant if a water agency’s system is currently operating at capacity and major system improvements are needed. In this case, the water agency may have to increase rates to reflect the higher marginal costs of future system expansion. During droughts, the rates water agencies charge may vary depending on supply availability. Agencies may have to acquire water from outside sources to meet service area needs or may have to construct interties orother conveyance system improvements to bring purchased supplies to their system. Many water agencies adopted higher rates to fund programs to encourage water conservation during the 1987-92 drought, and several implemented drought penalty rates intended to reduce water use drastically.

Characteristics of Service Area A water agency’s costs will be affected by the mix of residential, commercial, industrial, governmental, and agricultural users within the service area because the costof service to different classes of users is likely to be different. If a water agency serves a heavily populated area with many connections per square mile, the average fixed costsper customer will tend to be less. Conversely, if the purveyor serves a sparsely populated area, average fixed costs of serving each customer will normally be high. Because of pumping costs, changes in elevation within a service area can also affect delivery costs. Rate Structure Water rates are the primary source of income for most water agencies. Although rates can be structured many ways, they typically include fixed charges, consumption-based charges, or both. Fixed charges recover some or all of costs incurred regardless of the amount of water used, such as debt service incurred from project construction. Fixed charges are typically used by water agencies that do not meter consumption. Examples of fixed charges formetered urban water agencies include billing and administrative charges (service charges), lifeline charges for a minimum level of service, readiness to serve charges, and fire protection charges. Agricultural fixed charges (often called water availability or standbycharges) can be levied on a per acre or connection basis. Fixed charges which are levied on a per acre or parcel basis will likely be affected by Proposi tion 218, discussed in more detail in Chapters 2 and 6. Consumption-based charges are set on a per unit volume basis so the total charge varies with the user’s consumption. These charges typically recover variable costs of water deliveries (water purchases, treatment, and pumping). As with fixed rates, there are several forms of consumption-based rates. One form is the constant charge, which is the same unit price for all units of water consumed. Another is block rates, which decrease (declining block) or increase (increasing block) with water consumption. A declining block rate sets a reduced price per unit for increased usage. Increasing block rates set increasing prices per unit for increasedusage. Constant and increasing block rates are the predominant urban rate structures currently used in California. Some forms of declining rates are still used in urban areas, especially in communities using lower water rates as an incentive for industry to locate in their area. Some agencies use declining block rates and other incentives to encourage use of recycled water in lieu of potable supplies. Agricultural water agencies levy consumption-based charges based upon either the
actual amount of water delivered or on the number of irrigated acres (charges may vary depending upon the crop type). Fixed charges and consumption-based chargestypically account for most of a water agency’s total revenues. Revenues can also be obtained from assessments,or taxes, levied upon lands in accord with benefits received from an agency’s actions. Assessments recover a portion of an agency’s fixed costs, and can be levied4A-3 A PPENDIX 4A The California Water Plan Update B ULLETIN 160-98 Appendix 4A



### either on lands which directly benefit from water deliveries (for example, land receiving irrigation water)or on lands which indirectly benefit from water deliveries (adjoining lands which may benefit from groundwater recharge resulting from the deliveries). Cities may charge for sewers and sewage treatment based on water use. In some cities, the sewer chargesare included in monthly service charges and commodity rates paid by the water users. Other cities charge for sewers based on water use, but keep the sewer charges separate from the water charges.

Urban Retail Water Costs

Since 1990 there have been a few statewide surveys of urban retail water costs in California. One, conducted by the Department in 1991, included about 70 communities. The results of this survey are described in the Department’s Bulletin 166-4, Urban Water Use in California . DHS conducted another survey in 1990,and three others were conducted by a private consulting firm in 1993, 1995, and 1997. (The 1993-1997surveys were based on an assumed monthly consumption of 1,500 cubic feet of water per connection, anamount much lower than that used by many households. This assumption limits the usefulness of the survey data.) At a statewide level of coverage, there are no recent retail pricing data based on actual water use

amounts. In 1994, the accounting firm of Ernst & Young conducted a national water rates survey which MWDSC summarized in its 1995 Integrated Resources Plan. That survey showed that the national average for retail urban water supply was almost $600/af. MWDSC’s average was about $625/af; San Francisco’s was about $560/af; and Oakland’s was almost $700/ af. (Other urban areas had higher costs. Indianapolis was about $725/af; Houston was almost $900/af, and Nashville was more than $1,100/af.)

Impacts of Retail Prices on Water Use Price elasticity studies are used to characterize price responsiveness—the degree that water users increase or decrease use in response to a change in water price. Economists define price elasticity of demand as the ratio of the percentage change in quantity of water used to the percentage change in the price of water. When faced with a significant water price increase, urban water users may react in one of three ways: • They may use substantially less water. In this case, water users are sensitive to price changes, and demand is defined to be elastic (its absolute elasticity value is equal to or greater than one). For example,if a 10 percent increase in price caused a 10 percent reduction in demand, economists would
define demand as elastic. • They may use a little less water. In this case, waterusers are not very sensitive to price changes, and demand is said to be inelastic (absolute elasticity value is less than one). For example, if a 10 percent price increase caused a 5 percent reduction in demand,
demand would be defined as inelastic. • They may continue to use the same amount as before. In this case, the water users are completely insensitive to price changes, and demand is said to be perfectly inelastic (elasticity value is equal to zero). A 1989 EBMUD study, for example, estimatedprice elasticity of demand for its residential water supply to be -0.202 from 1981 through 1987. This meansthat a water price increase of 10 percent could be expected to lower the amount of water use by about 2percent. The demand for water in this case was inelastic—residential water users were found to be relatively insensitive to price changes. This has been the case for
most studies of residential water demand. Factors that can affect elasticity include climate, housing type, water users’ income, percentage share ofwater bills in users’ budgets, water rate structure, water conservation measures and education, and users’preferences regarding water use (some users may prefer to irrigate large turf areas regardless of cost). Table 4A-2 provides a survey of recent literature on urban water price elasticities of demand. These studies were performed with statistical modeling which employed historical water use, water price, and demographic and
climatic data. Elasticity estimates derived for one geographic areaare not necessarily representative of another area because of these many potential variables. It is generally not correct to take a value of residential price elasticity estimated for one community during one period oftime and to assume that it is applicable to another community, or for another period of time. Only by carefully examining the factors described above can elasticitiesdeveloped under one set of circumstances be reasonably used for estimating elasticities under other

circumstances. For Bulletin 160-98, the Department contracted4A-4 A

PPENDIX 4A The California Water Plan Update B ULLETIN 160-98 Appendix 4A

T ABLE 4A-2
Urban Water Demand Price Elasticity Studies

Author(s) Study Study Type of Estimated Range of Equivalent Prices Date Area Demand Elasticity Study Water ($/af) a
Prices

Moncur 1987 Honolulu, Hawaii Short-term -0.265 $0.22 - $0.36 $72 - $117
residential /1,000 gal Long-term -0.345 (1983 dollars)
residential

Metzner a 1989 San Francisco Long-term -0.25 $0.73 - $0.78 $318 - $340
residential /100 cu ft (1995 dollars)

Weber 1989 EBMUD Long-term -0.01 to -0.25 $0.24 - $0.94 $105 - $409
residential /100 cu ft (1989 dollars)

Nieswiadomy b 1989 Denton, Texas Long-term -0.55 to -0.86 $0.27 - $0.56 $88 - $183 & Molina residential /1,000 gal (1967 dollars)

Billings & Day 1989 Tucson, Arizona Long-term -0.72 $6.60 - $11.20 $7 - $11 residential monthly bills monthly bills 1974 -1980 (1974 dollars)

MWDSC 1990 South Coast Long-term Not Available Not Available Region single-family
residential
Summer -0.29 to -0.36
Winter -0.03 to -0.16

Schneider & 1991 Columbus, Ohio Short-term -0.262 Not Available Not Available
Whitlach residential Long-term -0.110 residential Short-term -0.504
total urban Long-term -0.123 total urban
Renwick et al. 1996 8 California cities Long-term -0.16 $0.47-$4.25 $205-$1,851 single-family /100 cu ft
residential

a Water rate data was unavailable from the study author. The Department retrieved the historical data and inflated the prices to 1995 levels for display

purposes only.

b Study was for summer months only and was a five-year period of recently adopted increasing block rates. Adjusted R 2 for models which produced -0.86 and -0.55 elasticities was only 0.26 and 0.11, respectively.


### with University of California researchers for an evaluation of the effects of water pricing and non-pricingdemand reduction actions (e.g., public education, rationing, subsidies for adoption of more efficient water use technologies) on urban residential water use. The study covered single-family residential use during 1989 to 1996, a time period incorporating the recent droughtand allowing evaluation of actions taken by water purveyors to reduce residential water use during thedrought. Eight water retailers whose service areas represent 24 percent of California’s population wereincluded—San Francisco PUC, Marin MWD, Contra Costa WD, East Bay MUD, City of San Bernardino, City of Santa Barbara, Los Angeles DWP,and City of San Diego. All of these agencies experienced price increases over the study period and all used4A-5 A PPENDIX 4A The California Water Plan Update B ULLETIN 160-98 Appendix 4A



### non-pricing demand reduction actions during the study period. Price elasticity was estimated to be -0.16 (meaning that a 10 percent price increase would result in a 1.6 percent demand reduction) over a range of marginal prices of $0.47 to $4.25 per hundred cubic feet, showing that residential demand was price inelastic over this range.
The urban water demand forecast used for Bulletin 160-98 assumed single-family residential price
elasticities of -0.1 for winter months and -0.2 for summer months. Studies of urban water pricing to date indicate that the role of pricing by itself in achieving demand reduction is small. The plot of urban water production over time shown in Figure 4-4 illustrated the strong response of water use to the 1987-92 drought. Actions taken by water agencies during the drought to encourage demand reduction—includingpublic education programs, voluntary rationing, rebates for plumbing retrofits—decreased residential water use. However, water use throughout the State is rebounding to earlier levels, even after significant price increases by some agencies. For example, Contra Costa WD increased its average water rates substantially tofinance construction of Los Vaqueros Reservoir. Between 1980 and 1997, CCWD’s average water price increased by about 217 percent (adjusted for inflation). Its use per residential unit declined by 9 percent, muchof which is likely due to plumbing retrofit and building code requirements for new plumbing, and public
education. Agricultural Water CostsIn December 1996, the Department mailed water cost surveys to more than 60 agricultural water agencies in California. This survey was conducted todetermine the range of average agricultural retail surface water costs in the State and to obtain informationon types of water charges being used. Table 4A-3 summarizes the results of this survey by hydrologic region. Many responding agencies based their charges on bothwater use and number of acres irrigated. The information is presented here to illustrate the variability of prices based on local circumstances. Agricultural groundwater costs vary considerably throughout California. Factors influencing these costs include depth to groundwater, water quality, and well yields. Many groundwater users are self-supplied, meaning that individual water users pump their own supplies rather than receiving them from a wateragency. Bulletin 160-93 showed general ranges of agricultural groundwater production costs. TheDepartment does not have sufficient new data to accurately update those general cost ranges for Bulletin
160-98.

Impacts of Price on Agricultural Water Use Price elasticity of demand for agricultural water is a measure of farmers’ responsiveness to changes in theprice of water. Researchers have used a variety of models (programming and econometrics) to estimate the agricultural water use price elasticity in different parts T

ABLE 4A-3
DWR Survey of 1996 Agricultural Surface Water Costs a

Region 1996 1996 Costs ($/af) Water Rates Basis (number of agencies) Total Weighted Max. Min. By Acre By Crop By af Used By Acre Total Deliveries Average & Acre & af (taf) Used

North Coast 80 10 12 220103 San Francisco Bay b

— — — — — — — — —- Central Coast 37 128 533 87 00224 South Coast 92 373 604 13 100178 Sacramento River 1,275 12 32 214128 San Joaquin River 1,339 22 23 8620147 Tulare Lake 2,672 42 16 1 9 1 0 4 6 11
North Lahontan b

— — — — — — — — —- South Lahontan 18 61 61 61 00101 Colorado River 3,403 13 14 820024 Statewide 8,916

——— 8 4 11 23 46

a Average retail costs to the farmer

b No responses4A-6 A

PPENDIX 4A The California Water Plan Update B ULLETIN 160-98 Appendix 4A



### of the country, and have concluded that demand for irrigation water is generally price inelastic, within price ranges typical for agricultural water use. Obviously, there is no other commodity that can be substituted for the water needed to grow crops. As Table 4A-4 illustrates, water costs are typically a relatively small percentage of the total cost of producing most crops.The Central Valley Production Model was used to estimate agricultural price elasticity in the Central Valley. CVPM price elasticity estimates for irrigation waterdemand are based on the level of production of various crops. CVPM also allows for changes in croppingpatterns as water becomes more scarce, more expensive, or both.
Results of CVPM studies are summarized in Table 4A-5. Surface water prices were increased for the studyby different increments, and groundwater costs increased as a result of changes in pumping depths. Both short- and long-term elasticities were estimated. In the short-term study, it was assumed that farmers did not have enough time to adjust to increases in water costs, while in the long-term farmers could switch to more efficient irrigation technologies.
The values in the table are estimates of a farmer’s ability to respond to water price changes. For example, if surface water prices increase by 10 percent in the Sacramento Valley, the demand for surface water will decline by 3.2 percent. The model runs indicated that demand for irrigation water was price inelastic overthe price ranges analyzed. Where groundwater is available in the Central Valley, farmers may increase their groundwater use if pumping costs are less than the costs of their surface water supplies.

CVPIA Tiered PricingSection 3405(d) of CVPIA required that new, renewed, or amended contracts for project water incorporate an inverted block rate pricing structurespecified in the act. The first rate tier applied to a quantity of water up to 80 percent of the contract total. The second rate tier applied to the quantity of waterfrom 80 percent to 90 percent of the water under contract, and was to be halfway between the rate for the first tier and the third tier. The third tier applied tothe quantity of water beyond 90 percent of the contract total, and was to be not less than USBR’s full cost rate. USBR’s municipal and industrial customers are already charged the full cost rate, which includes costof service, principal and interest on facility construction costs, and CVPIA Restoration Fund charges.As noted in Chapter 2, all of USBR’s contract renewals to date have been interim renewals, since the PEIS required by the act has not yet been completed. No long-term renewal contracts can be executed until USBR completes the PEIS, which is now expected to occur in 1999. Through 1996, interim contracts for project water supply represented about 16 percent of project water under contract. In its 1998 public draft PEIS, USBR used CVPM to estimate potential impacts of implementing tiered pricing as set forth in the act. USBR estimated that implementing tiered pricing would reduce average year CVP applied irrigation water in the CVP service area T

ABLE 4A-4
Average Water Costs as a Percent of Total

Production Costs for Selected Crops in
the Tulare Lake Region a

Crop Water Costs as a Percent of Total Costs
Irrigated pasture 36 Alfalfa hay 19 Barley 16 Dry beans 14
Wheat 14

Cotton 12 Sugar Beets 12
Safflower 11 Dry Onions 9 Almonds 6
Pistachios 6 Processing tomatoes 6 Wine grapes 5

a Data from output of the Department’s Central Valley Net Crop

Revenue Model.

T

ABLE 4A-5
Price Elasticities for Surface Water Irrigation Demand

Region Short-Term Elasticity Long-Term Elasticity Range of Water Prices ($/af)

Sacramento River -0.24 -0.32 20 - 240 San Joaquin River -0.20 -0.30 20 - 240
Tulare Lake -0.18 -0.24 20 - 2404A-7 A PPENDIX 4A The California Water Plan Update B ULLETIN 160-98 Appendix 4A



### by 266 taf from CVPIA’s assumed no-action condition. This amount took into consideration the shiftfrom CVP water use to groundwater use, in those areas having access to groundwater supplies. (The estimate assumed that USBR’s ability to pay policy for irrigation remained in effect for principal on capitaland Restoration Fund charges, at an estimated payment capacity of $11/af north of the Delta and $70/af south of the Delta.)USBR also evaluated alternatives to the tiered pricing specified in the act, including an analysis which assumed that ability to pay provisions were not in force. This approach would reduce applied irrigation water by an additional 25 taf in an average water year. Thegreatest reduction in applied irrigation water use occurred in USBR’s alternative which exceeded therequirements of the statute by applying full cost pricing to the first 80 percent of contract water supply, 110 percent of full cost pricing to the second tier, and 120 percent of full cost pricing to the last 10 percent of contract water supply. The draft PEIS estimated that this alternative would reduce applied irrigation water by about 570 taf in an average year.After USBR completes the CVPIA PEIS, longterm contract renewals can begin. The effects of tiered pricing on CVP water use will be manifested over time, as more contracts are renewed. The relationship of CVPtiered pricing to CVP water use, however, cannot necessarily be generalized to price/water use relationships for agricultural users served from non-USBR sources.Agricultural water users served by the SWP, local water projects, and self-supplied sources already pay full cost rates for their supplies.

Comparing Agricultural and Urban Water Costs Generally, agricultural water supply costs are lowerthan urban costs. Much of the State’s earliest largescale water development was for agriculture, and the irrigation works were constructed when water development was inexpensive by present standards. Also,there are basic differences in the delivery systems providing agricultural and urban water supplies. The price of water is determined by the cost of water at the source (from a reservoir or at the Delta, for example) plus the costs of using the facilities associated with conveying, storing, treating, and delivering the water to the final users. Some contracts for agricultural supplies haveallowed agricultural users to pay a lower price for water supplies in return for accepting supplies with a lower level of reliability. Typically this was achieved by deficiency provisions incorporated in the water supply contracts. Both urban and agricultural water agencies must pay transportation costs incurred to bring the water supplies to their service areas. However, agricultural agencies are often closer to the surface water sources and in many cases are able to rely on gravity-operated conveyance and distribution systems, avoiding energycosts associated with pressurized pipelines. Urban water supplies often travel through hundreds of miles ofcanals or pipelines, adding considerably to the transportation costs. For example, by 2000, power costs to deliver SWP water to the San Joaquin Valley service area are estimated to be about $15/af. Power costs to
deliver the same acre-foot of SWP water to the South Bay, Central Coast, and Southern California service areas are estimated to be about $34, $78, and $87, respectively. Urban water systems have additional delivery costs compared to agricultural systems. For example, urbanwater users must pay for terminal storage and pressurization of water. Monitoring and treating water forpublic health protection is expensive, and costs are expected to increase as a result of more stringent drinking water standards. Most urban water systems also incursubstantial costs to install and read meters, and to prepare billings.4A-8 A

PPENDIX 4A The California Water Plan Update B ULLETIN 160-98 Appendix 4A4B-1 A PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4B



### S

c,w,t 

### = U

w,t 

### * R

c,w



### * P

c,w,t



### where

S

c,w,t 

### = water savings resulting from the implementation of conservation measure c , in water use category w , at time t , expressed in gallons per day

U

w,t 

### = base year water use in water use category w at time t , expressed in gallons per capita per day

R

c,w



### = reduction in water consumption resulting from the implementation of conservation measure c , in water use category w , expressed as a proportion of base year water

use

P

c,w,t 

### = population affected by conservation measure c, in water use category w , at time t 

# BMP Revisions and Water Savings Assumptions

Table 4B-1 provides a synopsis of revisions to urban water conservation BMPs, as adopted by CUWCC in September 1997. Table 4B-2 summarizes BMP water savings assumptions specified in the Urban MOU.These assumptions served as the basis for urban water use study conservation savings calculations, according to the following general formula: 

# 4B4B-2 A

PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4B1Water Survey Programsfor Single-FamilyResidential andMultifamily ResidentialCustomersRemoves requirement tospecifically target top 20% ofresidential water users. Allowsagencies to develop targetingand marketing approachestailored to their service areas.Specifies minimum auditelements. Requires agencies todevelop database to trackprogram.Extends the implementationschedule 10 years from thedate the BMP is revised or thedate an agency signs theMOU, whichever is later.Replaces the requirement that70% of the top 20% ofresidential customers accept anaudit by September 1, 2001,with the requirement that15% of residential customersaccept an audit within 10␣ yearsof the date of implementationfor the agency.Requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.2Residential PlumbingRetrofitAdds requirement thatagencies maintain devicedistribution programs at levelssufficient to distribute retrofitkits to not less than 10% ofresidential accounts eachreporting period until coveragerequirement is met. Allowsagencies to use massdistribution methods asappropriate. Allows agencies todevelop targeting andmarketing approaches tailoredto their service areas. Requiresagencies to develop data baseto track program.Replaces the requirement thatagencies realize the coveragerequirement by September 1,2001, with the requirementthat they maintain theprogram at specified level untilthey can demonstrate coveragerequirement is met.Replaces the requirement that75% of single-family and 80%of multifamily residencesconstructed prior to 1980 areretrofitted with therequirement that 75% ofsingle-family and multifamilyresidences constructed prior to1992 are retrofitted.Requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.TABLE4B-1BMP RevisionsChanges to Existing BMP Definitions, Implementation Schedules, CoverageRequirements, and Reporting Requirements Contained in Exhibit 1 of the MOUBMP BMP Name Changes to Changes to Changes to Changes to ReportingNumberBMP Definition Implementation Schedule Coverage RequirementRequirement4B-3 A PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4B3 System Water Audits,Leak Detection andRepairReplaces requirement thatagencies conduct a completesystem audit every three yearswith requirement that agenciesconduct annual pre-screenaudits and conduct full systemaudits only if indicated by thepre-screen audit.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later.No change.Requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.4 Metering withCommodity Rates forAll New Connectionsand Retrofit of ExistingConnectionsAdds requirement thatagencies assess feasibility ofprogram to retrofit mixed-usemetered accounts withdedicated irrigation meters.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later. Extendsdate that coverage requirementmust be met from September1, 2001, to 10␣ years from thedate the BMP is revised or thedate an agency signs theMOU, whichever is later.No change.Requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.TABLE4B-1BMP RevisionsChanges to Existing BMP Definitions, Implementation Schedules, CoverageRequirements, and Reporting Requirements Contained in Exhibit 1 of the MOU (continued)BMP BMP Name Changes to Changes to Changes to Changes to ReportingNumberBMP Definition Implementation Schedule Coverage RequirementRequirement4B-4 A

PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4B5Large LandscapeConservation Programsand IncentivesAdds requirement thatagencies develop water usebudgets for accounts withdedicated irrigation meters.Removes requirement tospecifically target landscapes of3+ acres for audits. Continuesto require audits for customerswithout landscape water usebudgets. Continues to requirecustomer incentive programs.Allows agencies to developtargeting and marketingapproaches tailored to theirservice areas. Requires agenciesto develop database to trackprogram.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later. Allowsagencies 10 years from dateBMP implementation is to beunderway to meet coveragerequirement. Allows agenciesfour years to develop water usebudgets for dedicatedirrigation meter accounts.Removes requirement thatagencies offer audits to 100%of accounts with 3+ acres oflandscape by September 1,2001. Adds requirement thatagencies provide landscapeaudits to 15% of mixed-use,non-residential accountswithin 10 years from dateBMP implementation is to beunderway for agency. Addsrequirement that agencies offeraudits to not less than 20% ofmixed-use, non-residentialaccounts each reportingperiod. Allows agencies tosatisfy audit requirements byimplementing a mixed-usemeter retrofit program or aprogram to develop landscapewater use budgets for accountswith mixed-use meters.Requests data on the number ofaccounts with dedicated irrigationmeters, and number of waterbudgets established duringreporting period. Otherwise,requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.TABLE4B-1BMP RevisionsChanges to Existing BMP Definitions, Implementation Schedules, CoverageRequirements, and Reporting Requirements Contained in Exhibit 1 of the MOU (continued)BMP BMP Name Changes to Changes to Changes to Changes to ReportingNumberBMP Definition Implementation Schedule Coverage RequirementRequirement4B-5 A PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4B6(New)High-EfficiencyWashing MachineRebate ProgramsAdds requirement thatagencies offer maximum costeffective customer rebate forhigh-efficiency washingmachines if energy serviceprovider in service area is alsooffering rebates.7Public InformationProgramsAdds requirement thatagencies conduct publicawareness surveys every threeyears to assess conservationattitudes and guide programdesign.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later.No change.Requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.8 School EducationProgramsNo substantive changes.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later.No change. Requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.9Conservation Programsfor Commercial,Industrial, andInstitutional AccountsReplaces audit requirementwith a two track approach. Anagency can choose either toimplement an audit programfor CII customers, or to meet awater savings performancetarget for the CII sector.Requires CUWCC to developlong-term CII ULFTimplementation targets basedon findings of CUWCC CIIULFT water savings studywithin one year of BMPadoption.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later. Allowsagency 10 years from dateBMP implementation is to bestarted to begin meetingcoverage requirement.Requires either 10% ofcommercial, industrial, andinstitutional accounts toaccept an audit within 10␣ yearsor a reduction in water use bycommercial, industrial, andinstitutional accounts by anamount equal to 10% of theuse by the top 10% ofaccounts.Requires agencies to substantiateeither completed audits or watersavings estimates. Requestssubstantially more information onprogram design andimplementation than what iscurrently being collected throughCUWCC annual reports.TABLE4B-1BMP RevisionsChanges to Existing BMP Definitions, Implementation Schedules, CoverageRequirements, and Reporting Requirements Contained in Exhibit 1 of the MOU (continued)BMPBMP NameChanges toChanges toChanges toChanges to ReportingNumberBMP Definition Implementation Schedule Coverage RequirementRequirementN/AN/AN/A4B-6 A

PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4B10(New)Wholesale AgencyAssistance ProgramsDefines wholesale agencysupport roles in terms offinancial, technical, andprogrammatic assistance toretail agencies implementingBMPs.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later.Requires wholesalers to justifyfinancial, technical, andprogrammatic support levels.Requires additional reporting bywholesale agencies over what iscurrently being collected throughCUWCC annual reports.11Conservation PricingRetains current definitions ofnon-conserving and con-serving rate structures. Addsrequirement that CUWCCundertake a study toempirically assess the affect ofrate structure on customerwater use patterns andquantities, and to specificallyexamine the relationshipbetween customer demandand the proportion of agencyrevenue requirement recoveredthrough commodity charges,fixed charges, and other servicecharges.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later.No change.Requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.12(formerlyBMP 14)ConservationCoordinatorNo substantive change.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later.No change.Requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.TABLE4B-1BMP RevisionsChanges to Existing BMP Definitions, Implementation Schedules, CoverageRequirements, and Reporting Requirements Contained in Exhibit 1 of the MOU (continued)BMP BMP Name Changes to Changes to Changes to Changes to ReportingNumberBMP Definition Implementation Schedule Coverage RequirementRequirement4B-7 A PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4B13 Water WasteProhibitionNo substantive change.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later.No change.Requires similar types andamounts of information ascurrently being collected inCUWCC annual reports.TABLE4B-1BMP RevisionsChanges to Existing BMP Definitions, Implementation Schedules, CoverageRequirements, and Reporting Requirements Contained in Exhibit 1 of the MOU (continued)BMP BMP Name Changes to Changes to Changes to Changes to ReportingNumberBMP Definition Implementation Schedule Coverage RequirementRequirement14(formerlyBMP 16)Residential ULFTReplacement ProgramsRemoves reference to CIIULFT replacementrequirements; otherwise nosubstantive change.Makes implementationschedule relative to the datethe BMP is revised or the datean agency signs the MOU,whichever is later. Allowsagency 10 years from dateimplementation is tocommence to meet coveragerequirement.No change.Requests similar types andamounts of information ascurrently being collected inCUWCC annual reports.4B-8 A

PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4BTABLE4B-2BMP Water Savings AssumptionsBMPBMP NameMOU Savings AssumptionsUrban Water Use StudyNumberCoverage RequirementReduction FactorModeling Assumptions1Water Survey Programs for SingleFamily and Multifamily Customers15% of residential accounts.Pre-1980 ConstructionShower head replacement: 7.2 gpcdToilet retrofit: 1.3 gpcdLandscape Audit: 10% of outdoor usePost-1980 ConstructionShower head replacement: 2.9 gpcdToilet retrofit: 0 gpcdLandscape Audit: 10% of outdoor useModeled based on MOUsavings assumptions.2 Residential Plumbing Retrofit75% of single-family and multifamilyresidences.Pre-1980 ConstructionShower head replacement: 7.2 gpcdToilet retrofit: 1.3 gpcdPost-1980 ConstructionShower head replacement: 2.9 gpcdToilet retrofit: 0 gpcdModeled based on MOUsavings assumptions.3System Water Audits, Leak Detection,and RepairMaintain active distribution systemauditing program and repair systemleaks when cost-effective.Unaccounted water losses assumed tobe no more than 10% of total waterinto the suppliers’ system.Not modeled because statewideaverage unaccounted water losscurrently meets the MOU targetvalue.4Metering with commodity rates for allnew connections and retrofit of existingconnections100% of unmetered accounts to bemetered and billed by volume of use.20% reduction in demand byretrofitted accounts.Modeled based on MOUsavings assumptions.5Large Landscape ConservationPrograms and IncentivesETo- based water use budgets for 90%of accounts with dedicated irrigationmeters; irrigation water use surveys for15% of CII accounts with mixed usemeters.15% reduction in irrigation waterdemand for surveyed landscapes.Not modeled due to insufficientbase year data on landscapewater use and acreage.6High-Efficiency Washing MachineRebate ProgramsCost-effective customer incentive forthe purchase of high-efficiency washingmachines to be offered if incentives arebeing offered by local energy provideror wastewater utility.Not quantified at this time.Not modeled due to “notquantified” status in MOU.4B-9 A PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4BTABLE4B-2BMP Water Savings Assumptions (continued)BMP BMP NameMOU Savings AssumptionsUrban Water Use StudyNumberCoverage RequirementReduction FactorModeling Assumptions7Public Information ProgramsMaintain an active public informationprogram to promote and educatecustomers about water conservation.Not quantified.Not modeled due to “notquantified” status in MOU.8 School Education ProgramsMaintain an active school educationprogram to educate students inagencies’ service areas about waterconservation and efficient water uses.Not quantified.Not modeled due to “notquantified” status in MOU.9Conservation Programs forCommercial, Industrial, andInstitutional Accounts10% of CII customers to accept a wateruse survey or reduce water use by CIIcustomers by an amount equal to 10%of baseline CII water use.Commercial Water Use12% reduction in water use (gallonsper employee per day) occurring from1980-2000.Industrial Water Use15% reduction in water use (gallonsper employee per day) occurring from1980-2000.Modeled based on MOUsavings assumptions.Modeled based on MOUsavings assumptions.10 Wholesale Agency Assistance ProgramsReport on cost effectiveness of eachBMP the agency is potential obligatedto support, agency avoided cost peracre-foot of new water supplies,monetary value of financial incentiveand resources provided to retailmembers to assist or support BMPimplementation, and amount ofverified water savings achieved by eachwholesaler-assisted BMP.Not quantified.Not modeled due to “notquantified” status in MOU.11Conservation PricingMaintain rate structure consistent withthe definition of conservation pricingspecified in the MOU.Not quantified.Although not quantified by theMOU, this BMP was modeledon the basis of DWR waterprice forecasts and recent studiesof urban water price elasticity inCalifornia.4B-10 A

PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4BTABLE4B-2BMP Water Savings Assumptions (continued)BMP BMP NameMOU Savings AssumptionsUrban Water Use StudyNumberCoverage RequirementReduction FactorModeling Assumptions12Conservation CoordinatorMaintain and staff the position ofconservation coordinator and providesupport staff as necessary.Not quantified.Not modeled due to “notquantified” status in MOU.13Water Waste ProhibitionAdopt water waste prohibitionsconsistent with the provisions specifiedin the MOU for this BMP.Not quantified.Not modeled due to “notquantified” status in MOU.14 Residential ULFT ReplacementProgramsSavings to equal or exceed watersavings achievable through anordinance requiring the replacement ofhigh water using toilets with ULFTsupon resale.At least as effective as requiring toiletreplacement at the time of resale.(Exhibit 6 of the MOU presents adetailed methodology for estimatingsavings).Modeled based on MOUsavings assumptions.4B-11 A PPENDIX 4B The California Water Plan Update B ULLETIN 160-98 Appendix 4B4C-1 A PPENDIX 4C The California Water Plan Update B ULLETIN 160-98 Appendix 4C 

# 4C

Normalizing Urban Water Use Data

Some of the public comments the Department received on the draft Bulletin 160-98 dealt with how normalized urban water use data were developed andwhy normalized data differed from actual water production data. This appendix is provided to address
those comments.Bulletin 160-98 estimates of urban water use begin with raw data from the Department’s survey ofpublic water systems. This survey provides local agencies’ annual water production which, when combined with population data, can be shown as agency per capita water production. For each of the Bulletin 160 DAUs(or in some cases, PSAs) representative water purveyors are selected, and their production data are quality-controlled to fill in missing data points, check production numbers, and resolve inconsistencies in the
data.Figure 4-4 in Chapter 4 showed how average statewide urban water production has varied over time. Information used to prepare the figure came from the public water systems surveys. Figure 4C-1 shows sample data for 12 cities or water agencies, to illustrate geographic variability in production, together with statewide average water production. These plotted datado not include self-produced water, water that is developed by entities for their own use. Most self-produced water is developed by industrial users. The Department estimates quantities of self-producedwater through periodic surveys of industrial water users. Statewide, the residential sector accounts for overhalf of total urban water use. The landscape component of residential (and some commercial andinstitutional) use strongly influences year-to-year variations in urban use, reflecting availability of precipitation and other water sources. Landscape water use increases in dry years in most parts of the State, if water supplies are available, since less precipitation occurs. Regionalvariations in landscape water use reflect climatic differences and the extent to which available water supplies depend on local precipitation or on supplies from other

sources.

F IGURE 4C-1
Sample Urban Water Production Data

0 50 100 150 200 250 300 350 400 450

1995 1990 1985 1980Gallons Per Capita Daily

Bakersfield

CCWD EBMUD Fresno Statewide Average4C-2 A

PPENDIX 4C The California Water Plan Update B ULLETIN 160-98 Appendix 4C



### Addressing the impacts of the 1987-92 droughtwas a major consideration in reviewing the water purveyor data used for Bulletin 160-98. As shown in Figure4-4, statewide average urban per capita water production declined during the drought years due to water rationing and other short-term restrictions in use, but then began to rebound. Capturing this rebound effect was important to estimating 1995 normalized urban use for Bulletin 160-98. As described in Chapter 4, the normalizing process is intended to remove water use irregularities due to droughts, extremely wet years, or other conditions. Calendar year 1995 was a wet year. Actual urban water production data for 1995 are thus lower than the Bulletin 160 normalized urban water
use data.
Normalized urban water use is calculated for each DAU, except in the sparsely populated desert areas in southeastern California, where calculations are doneat a PSA level. Recent production data from representative water purveyors are combined with normal watersupplies and water use patterns to produce a composite per capita water production value for each DAU. Data for years during and immediately following the drought are removed from consideration due to the effects of water shortages of unprecedented severity and duration and a multi-year rebound in per capita water F IGURE 4C-1 (continued)

F IGURE 4C-1 (continued)

0 50 100 150 200 250 300 350 400 450

1995 1990 1985 1980G a l l o n s P e r C a p i t a D a i l y

Victor Valley County WD

Santa Barbara San Diego

San Francisco S ta tewide Average 0 50 100 150 200 250 300 350 400 450

1995 1990 1985 1980G a l l o n s P e r C a p i t a D a i l y

S ta tewide Average Sacramento

Marin MWD LADWP San Bernardino4C-3 A PPENDIX 4C The California Water Plan Update B ULLETIN 160-98 Appendix 4C



### use. The composite per capita water production value is adjusted to account for self-produced water supplies, permanent effects of urban BMPs, and post-1990changes to federal and State plumbing fixture standards to result in base year per capita water use. The amount by which a normalized value differs from actual production data for a given year varies from DAU to DAU, as shown in Figure 4C-2 for somesample DAUs. (The 1995 statewide average normalized per capita urban water use was 229 gpcd, of which 9 gpcd represented self-produced water.) Normalized per capita water use data (water purveyor production plus self-produced water) are multiplied by the corresponding population to arrive at base 1995 normalized
urban water use for each DAU. When DAU-level information is combined into hydrologic regions for Bulletin 160 water budgets, the “other” component ofurban water use is added to the regional water budgets. This “other” component is small in comparison and includes recreation water use, energy production water use, and losses from major conveyance facilities. (With the addition of the “other” component, total 1995 normalized statewide average per capita water use is 244 gpcd.)

San Jose DAU 44 Orange DAU 96 F IGURE 4C-2

Actual and Normalized Production Data

0 50 100 150 200 250 300 350

1995 1990 1985 1980G a l l o n s P e r C a p i t a D a i l y

Actual 1 9 9 5 Av e ra g e Ye a r ( No r m a l i z e d ) 

# +

0 50 100 150 200 250 300 350

1995 1990 1985 1980G a l l o n s P e r C a p i t a D a i l y

1 9 9 5 Av e ra g e Ye a r ( No r m a l i z e d ) 

# +

Actual4C-4 A

PPENDIX 4C The California Water Plan Update B ULLETIN 160-98 Appendix 4C

0 50 100 150 200 250 300 350

1995 1990 1985 1980G a l l o n s P e r C a p i t a D a i l y 1 9 9 5 Av e ra g e Ye a r ( No r m a l i z e d ) 

# +

Actual Placer DAU 172 F IGURE 4C-2

(continued)

0 50 100 150 200 250 300 350

1995 1990 1985 1980G a l l o n s P e r C a p i t a D a i l y

1 9 9 5 Av e ra g e Ye a r ( No r m a l i z e d ) 

# +

Actual

Oakland DAU 47 (Alameda County portion)

Fresno DAU 233

0 50 100 150 200 250 300 350

1995 1990 1985 1980G a l l o n s P e r C a p i t a D a i l y

Includes 29 gpcd self-produced industrial water use not accounted for in the plot of actual production data. 1 9 9 5 Av e ra g e Ye a r ( No r m a l i z e d ) 

# +

Actual a

a4C-5 A PPENDIX 4C The California Water Plan Update B ULLETIN 160-98 Appendix 4CT ECHNOLOGY I N W ATER M ANAGEMENT 5-1 The California Water Plan Update B ULLETIN 160-98



# Technology In Water Management 

# T his chapter highlights the present status and anticipated development

of water management technologies. Review of water management technologies provides an important foundation for evaluating water

management options described in later chapters of the Bulletin. For example, it is a common public perception that seawater desalting will solve most of California’s future water

problems. However, the current and reasonably foreseen state of desalting technology suggests that it will be used to meet relatively small, specialized needs due to its high cost. This

chapter presents some case histories of selected technology applications and illustrates a

few innovative examples.

Demand Reduction Technologies

Technological advances have improved urban and agricultural water use efficiency

throughout the State. Future advances are expected to affect landscape irrigation, residential

indoor water use, interior commercial, institutional, and industrial

water use, and agricultural water use. Since the purpose of the

Department’s Bulletin 160 series is to assess water supply benefits, it is

that aspect of demand reduction that the Bulletin addresses. Demand

reduction technologies may provide additional benefits, such as reducing

water treatment costs, reducing fish entrainment at water supply The city of Santa

Barbara’s desalter
was operated
during the drought

in 1992 and is now

on standby status.T ECHNOLOGY I N W ATER M ANAGEMENT 5-2 The California Water Plan Update B ULLETIN 160-98



### diversion structures, or reducing nonpoint source runoff. These other benefits are recognized in the Bulletin’s options evaluation process, as described in Chapter 6.

Landscape Irrigation Technology
New irrigation control system technology can save water by setting irrigation cycles to account for changes
in such factors as soil moisture and ET. New technology includes both retrofit devices and redesigned irrigation controllers.Residential landscape irrigation systems often include sophisticated control devices such as electronic
timers and electric solenoid-controlled valves. This increased sophistication does not always translate intowater savings because homeowners often lack information on landscape plant water requirements. Consequently, many residential irrigation timers are permanently set to meet maximum summer seasonwater requirements. A 1997 study by Utah State University showed that significant water savings could be achieved by retrofitting existing residential irrigation control systems with inexpensive (about $100) soilmoisture-sensing devices. The devices are placed inline between the existing timer and valves and overridea planned irrigation cycle when adequate soil moisture is available. Study results showed that the devices reduced landscape irrigation water use by an average of 10 percent. Follow-up questionnaires revealed that over 70 percent of the study participants observed thattheir lawns were as green or greener than before installation of the device.New irrigation system controllers for the commercial, industrial, and institutional sectors are programmed for irrigation schedules based on normalyear ET rates, and are adjustable to account for deviations from normal year ET. Some of the most advanced controllers can be automatically adjusted to current ET rates using telecommunication pager technology
to access weather data from automated weather stations. Rainfall sensors represent an inexpensive methodto automatically terminate irrigation controller programs during precipitation.

Residential Indoor Water Use TechnologyTechnological advances in residential indoor water use efficiency have come primarily from redesigningplumbing fixtures to meet new State and federal standards. Future efficiencies will come from improved
fixtures and installation of more water-efficient homeappliances. In addition, new technology to characterize residential water use may yield data allowing moreaccurate forecasts of components of urban water demand. This information would help allocate demand reduction program resources. Previously, the breakdown of residential water use was estimated from water meter data and assumptions about the water use of various fixtures and appliances. However, a 1995 study in Boulder, Colorado, showed that detailed information on water use patterns could be gathered through analysis of data obtained from data loggers attached to residential water meters. The traces have sufficient detail to identify flow signatures of individual fixtures and appliances. The techniquealso provides information to differentiate between indoor and outdoor water use. Based on the success of the Boulder study, a larger study was organized by the
American Water Works Association Research Foundation. The goal of this study is to collect informationfrom 1,200 homes in 12 cities, for two 2-week periods—one period in the winter and another in the summer. The information will be sorted into its major end use components: toilets, showers, baths, faucets, dishwashers, washing machines, and leaks. Preliminaryresults are shown in Table 5-1. These data will be combined with information from a survey of study participants to construct a residential water use model.A final report on the study is scheduled for publication in 1999. Plumbing Fixtures. State law requires all toilets
sold or installed in California to use no more than1.6 gallons per flush. These standards have pushed traditional gravity operated toilets to the limit ofacceptable operation. The performance of gravity operated toilets is limited to the flow rate achieved through the bowl under the force of gravity, placing alimit on the potential for reducing the amount of water used in each flush. Pressure-assisted toilets use pressurized flow, in conjunction with siphon action, to give acceptable

T

ABLE 5-1

Distribution of Residential Indoor Water Use

Component Average Use (%)

Toilet 26 Washing Machines 23 Shower/Bath 20
Faucets 15 Leaks 13 Dishwasher 1 Other Uses 2T ECHNOLOGY I N W ATER M ANAGEMENT 5-3 The California Water Plan Update B ULLETIN 160-98

High efficiency horizontal axis washing machines are being used in commercial applications, but are just becoming available for home use. A check of large appliance dealers in 1998 showed that two brands of horizontal axis washers were commonly in stock, at prices ranging from $700 to $1,100. Comparable standard washers cost from $100 to $600 less. Some utilities are offering their customers rebates on the order of $100 to $150 for purchasing the horizontal axis
machines. 

### operation with less flushing water. The increased flow rate (more than 70 gpm compared to about 25 gpm for gravity designs) provides greater force to remove
solids from the bowl and hastens the start of the siphon action. In addition, the surge of water from a pressure-assisted toilet is more effective at pushing waste through the drain line. In the past, use of pressure-assisted technology was limited to the commercial sector due to high costs and increased noise. Current residential designs are less expensive than previous models and only slightly noisier than gravity toilets. Pressure-assisted toilets range in price from $220 to $815, compared to $65 to $575 for gravity toilets. Future residential designs may use 0.5 gallons or less per flush. Washing Machines. Horizontal-axis washingmachines (front loading washing machines) use significantly less water than traditional vertical-axis,central agitator machines. Rather than fully immersing the clothes, the tub of the washer rotates through a horizontal axis in alternating directions to lift and tumble the clothes through a pool of water. Recentstudies show that these washers use about 25 to 35 percent less water than central agitator models.Currently, horizontal axis washing machines produced by American manufacturers range in price from about $700 to $1,100. Models by some European manufacturers are considerably more expensive. Pricesare expected to decrease to within about $200 of central agitator models as the market grows. A recentsurvey of appliance retailers showed the residential market for front loading washers could increase from about 2 percent at present to between 5 to 20 percent over the next five years.

Water Heaters. Hot water demand systems save water by either eliminating the need to drain cold water sitting in the pipe between the water heater and the plumbing fixture, or by reducing the distance between the heater and fixture. Demand systems are designed in two basic configurations: central storage tank and tankless systems. Central storage tank systems are based on traditional water heater and plumbing systems, modified with the addition of a valve to open a loop back to the hot water tank, and a pump to push the cold water back to the water heater while drawing hotwater into the pipe. When hot water reaches the fixture, the loop closes and the hot water exits the fixture.Tankless systems, also known as instantaneous or ondemand water heaters, heat water only when needed.They can be located near the plumbing fixture to reduce the amount of cold water that must be displaced for hot water to reach the fixture. Because they do notstore hot water, tankless systems save energy by eliminating standby losses. Water savings depend on the amount of water to be displaced before hot water reaches the fixture (or the amount of water that would have been displaced, in the case of tankless systems). Measurements by the California Energy Commission show that about two times the pipe volume between the water heater and the fixture must be replaced before hot water reaches the fixture, due to heat lost to the pipe. A 1996 study of potential water savings in Southern Californiashowed that hot water demand systems could save approximately 30 gpd per unit.

Interior CII Water Use Technology Plumbing Fixtures. The water savings potential of 0.5 gpf toilets also applies to the commercial sector. In addition, while State law requires that urinals useno more than an average of 1.0 gpf, this water requirement could be further reduced or eliminated through
the use of waterless urinals. Waterless urinals attach toT ECHNOLOGY I N W ATER M ANAGEMENT 5-4 The California Water Plan Update B ULLETIN 160-98



### standard plumbing stubs, but require no flushing water to operate. Water savings from waterless urinals depends onthe frequency of use and the flushing water requirement of the fixture that is replaced. A 1996 study in Southern California showed potential savings from about 11 gpd per fixture in office buildings to about 55 gpd per fixture in airports and movie theaters. In1995, the U.S. Navy equipped sample bathroom facilities at the Naval Air Station North Island in San Diego with waterless urinals. The study found that replacement saved about 45,000 gallons of water per year, with a pay-back period of about 3 years. Based on the success of the trial, more than 200 waterlessurinals were installed at the station. To date, the urinals remain in operation and perform well whenmaintained according to manufacturer recommendations. Cooling Towers. The largest use of water in the industrial sector is for cooling. Water is used to cool heat-generating equipment, manufactured products, and food products and containers in canneries. The most water-intensive cooling method is once-throughcooling, where water contacts and lowers the temperature of a heat source, then is discharged to waste. Recirculating cooling tower systems reduce water use by using the same water for several cycles. The majority of cooling towers in California arerecirculating evaporative systems, where the temperature of the cooling water is reduced through evaporation. As cooling water is recycled through the

Evaporative cooling towers are used by a wide range of
industries. 

### tower, the salt concentration increases. Salt build-up must be managed to avoid scaling on condenser tubes, which results in reduced heat transfer efficiency. Blowdown is the release of some of the circulating waterto remove the suspended and dissolved solids left behind due to evaporation. Make-up water is added in place of the blowdown to reduce the total dissolved solids. Water savings can accrue by minimizing blowdown or by converting to a dry cooling process based on air heat exchangers.Blowdown can be minimized by treating the recirculating water with sulfuric acid or ozone (to controlscaling and biological fouling), by mechanical filtration of solids, and by the use of conductivity sensors and automatic valves to precisely control the blowdown/makeup process. Savings can be maintainedthrough regular calibration of the conductivity sensors. A 1996 study conducted for MWDSC suggestedthat the majority of potential cooling tower water savings in Southern California could be realized throughthe addition and/or calibration of conductivity controllers. Water savings estimates ranged from about 400 to more than 900 gpd per site. Air heat exchangers use fans to blow air past finned tubes carrying the recirculating cooling water. ThePacific Power and Light Company’s Wyodak Generating Station in Wyoming uses dry cooling to eliminatewater losses from cooling water blowdown and evaporation. The processed steam is condensed by routing it through finned carbon steel tubes as fans force air, at a rate of 45 million cubic feet per minute, throughan 8 million square foot finned-tube surface. This technique results in a water requirement of 300 gpm, compared to about 4,000 gpm of make-up water for equivalent evaporative cooling.

Agricultural Water Use Technology Future technological advances in irrigation systems and irrigation scheduling are expected to result in more efficient agricultural water use. Irrigation Systems. Many terms are used in describing the performance of irrigation systems, but the two most important are DU and SAE, defined in Chapter 4. The accompanying sidebar defines severalagricultural technology terms used throughout this section. Irrigation experts generally agree that an 80 percent DU is achievable by all irrigation systems and is an upper limit for existing systems. With today’ssystems, SAEs of more than 73 percent indicate under-irrigation, potentially resulting in a reduction ofT ECHNOLOGY I N W ATER M ANAGEMENT 5-5 The California Water Plan Update B ULLETIN 160-98



### crop production and an increase in soil salinization.Whether a gravity or pressurized system, a well-designed and well-managed irrigation system appropriate to a field’s ter rain, soil, crop, and flow
constraints can achieve the maximum DU and result in high SAE, provided the irrigation water supply is of adequate quality and is available when needed at the proper rate of delivery. Adoption of new irrigation technology to reduceapplied water must result in a reduction of deep percolation, tailwater runoff, ET, or leaching requirement. Reduced deep percolation and tailwater runoff couldbe achieved by improving in DUs and irrigation management. Evapotranspiration could be reduced byminimizing losses from surface evaporation, or by intentional underirrigation with no loss in production or quality. Reducing the leaching requirement (the amount of water used to leach salts from the soil) isnot a goal because insufficient leaching results in salinization of the soil, rendering it less productive and consequently reducing water use efficiency. Gravity, or surface irrigation, systems use the soil surface to spread and move water on and over a field. The major types of gravity irrigation systems used in California—furrows, border-strip, and level basin— are discussed in the sidebar. The field is optimally rectangular, with the water entering the field from the highest side. The water moves over the surface of thesoil, eventually covering the area intended for irrigation, and infiltrates the soil to replenish soil moisture. The rate of infiltration varies by soil type and time (a sandy soil has a much higher infiltration rate than a clay soil). All soils have a maximum infiltration rate at the beginning of irrigation. The longer the water is incontact with the soil, the more the infiltration rate decreases; in some soils it decreases to almost zero.Important factors for achieving high DUs are intake opportunity time and soil infiltration rate. TheIOT varies within an irrigated field. On furrow systems, the part of the field closest to the source of water usually has the highest IOT. For high DUs, the IOTwithin a field must have a high uniformity. In addition, soil will affect the DU. Different soils with the
same IOT will have different infiltration rates. Themore nonhomogeous the soil, the more soil infiltration rates will vary, resulting in a lower DU. Irrigation timing, applying the correct amount ofwater, and having a high DU are important considerations for achieving high SAE. With most surface systems, the grower must decide how dry the soil can become (its allowable depletion) before an irrigation is applied. The grower’s decision is based on the field, irrigation system design, crop, soil depth, and other factors. If the soil has an AD of 3 inches, irrigation
should occur when the soil in the field has dried to that level. The amount of water applied over the field should be more than 3 inches, because water cannotbe applied with a DU of 100 percent. Irrigating before reaching the AD could result in an over-application of water, and a lower SAE. Irrigating after reaching the AD might result in an under-application, and an overly high SAE, which is not desirable because plant

stress may occur.Pressurized, or piped, irrigation systems use pipelines and water emission devices to discharge water into
a field and onto or under the soil surface. Water is pressurized using a pump and is usually passed through a filter to reduce the chance of clogging the emission devices. The water is distributed from a main pipeline system and sub-mains to lateral pipelines in the cropped
field. Water flows from the emission devices as either a spray or a very small continuous stream. As the water meets the soil, it infiltrates to replenish soil moisture. Pressurized systems are very different from surface systems. The performance of surface systems depends upon soil infiltration rates, IOT, and the amount ofwater applied. With pressurized systems, DU is constant and depends on the hardware design andmaintenance. The DU will not change, unless pipeline leaks or clogging of devices occur, or winds distort the spray pattern. One of the most important designconsiderations for achieving high DUs is pressure regulation, as flow rates change with pressure. Excessive Definition of Irrigation Terms • Distribution Uniformity: A measure of the variation

in the amount of water applied to the soil surface throughout an irrigated area. • Seasonal Application Efficiency: The water

beneficially used for ETAW and cultural practices divided by applied water. • Intake Opportunity Time: The amount of time that

applied irrigation water is in contact with the soil. • Allowable Depletion: Depth of water needed to bring

soil moisture to field capacity—a measure of how dry the soil is allowed to become before an irrigation is applied. • Reference Evapotranspiration (ET

o ): The ET of wellwatered 4 to 6 inch tall turf.T ECHNOLOGY I N W ATER M ANAGEMENT 5-6 The California Water Plan Update B ULLETIN 160-98



### pressure variations in the design will result in a low

DU. The most important considerations for achieving high SAE with pressurized systems are applying the correct amount of water during an irrigation, and maintaining a high DU. Since a pressurized systemcan apply any amount of water with the same uniformity, the amount of water needed to replenish the crop root zone must be determined before the irrigation. Then the irrigation can be operated for the correctamount of time to apply the required water. The major types of pressurized irrigation systems used inCalifornia—sprinkler and micro-irrigation—are discussed in the sidebar. Irrigation Scheduling. All irrigation systems require proper scheduling to achieve high SAEs. To develop an optimized irrigation schedule, the grower considers several factors: allowable or desirable crop water stress, the soil’s water holding capacity within the crop root zone, water availability and/or deliveryconstraints, amount of effective rainfall, and application rate. With this information, along with soil moisture determinations, plant stress indices, and/or estimates of crop ET, a grower can develop a water budget schedule. The water budget compares crop ET with soil AD, allowing the grower to decide when and how long to irrigate.Soil moisture is monitored many ways. Subsurface soil samples can be taken and visually inspected
to estimate the moisture status. Soil moisture can be
estimated with mechanical devices such as tensiometers or with electrical resistance devices such as gypsum blocks that rely on the change in electrical conductivity of water in the device. A neutron probe, another moisture-sensing device, measures the amount
of neutrons reflected from water molecules in the soil.

continued ... Gravity (Surface) Irrigation Systems Furrow Systems

Furrow is the most common gravity system, and is used for field crops, truck crops, trees, and vines. Channels or corrugations are cut or pressed into the soil of a field, usually one furrow between planted rows of crops. Efficient furrow systems have a slight grade, sloping from the head of the field
where water enters the furrows to the bottom of the field. Water is delivered to the furrows using an earthen ditch and siphon tubes, gated pipe, or underground piping and above ground valves. In furrow systems, only the soil in the channel is wetted. Between 20 to 50 percent of the soil surface in a furrow irrigated field usually comes in contact with the irrigation water.

To irrigate sloping furrow systems efficiently, tailwater is allowed to run off the end of the furrows. A tailwater recovery system is needed to reapply this water, either on the same field or on another field. Efficient management requires a relatively high flow at the beginning of the irrigation, to get the water down the furrow quickly, then the flow is cut back to reduce tailwater. With furrow systems, high DUs can be achieved when the advance time (the time it takes the water to move from the top of the field to the end) is relatively short compared to the total time of irrigation.

Furrow systems can be designed and operated to achieve good SAEs for a range of ADs, except for very small ADs. The AD changes as the root zone changes. The early season irrigation of annual crops will not be as efficient as later season irrigations, because the early season AD would be small (shallow root depths), while the later season AD would be large (deep roots). Infiltration rates are typically higher soon after planting and lower later in the season. Technologies and actions to optimize DUs and increase SAEs for furrow systems include: • Dragging torpedoes (heavy metal cylindrical devices) within

a furrow to smooth and compact the soil surface will decrease the advance time. This is most effective for early season irrigations, where the soil surface is rough due to tillage, and the soil intake rate is high. • Shortening the length of the furrow will result in decreased

advance time. (Shortening furrows increases the number of furrows, which can also result in less planted acreage and an increase in the cost of irrigation.) • Laser leveling of fields to achieve a uniform slope, and a

steeper slope (if practical), will decrease the advance time. • Using surge irrigation, a technique where short term

opening and closing of valves provides water to the furrows, resulting in the water “surging” down the furrow. (This technique is better suited to some soil types than others.) This technique will improve the uniformity of IOT in a furrow. It requires a surge valve designed for this application, and can easily be automated. • Reducing the flow rate in each furrow after the water has

reached the end of the furrow is essential to reducing the amount of tailwater produced. • Using a properly planned and designed tailwater recovery

system, along with efficiently using the captured tailwater on the same field or other irrigated fields.

Border-Strip Systems

Border-strip systems are generally used for alfalfa and pasture, but can be used on field crops and trees and vines. A field is divided into a number of strips, usually between 20 toT ECHNOLOGY I N W ATER M ANAGEMENT 5-7 The California Water Plan Update B ULLETIN 160-98

A side roll, wheel move sprinkler system. 100 feet wide. Low levees, or borders, divide each strip. Each strip has a slight slope from the head of the strip to the bottom, and ideally little or no slope between the sides. Water is delivered to each strip using an earthen ditch and siphon tubes, gated pipe, or underground piping and above ground valves. Usually all the soil surface in the strip, other than that in the borders, comes in contact with irrigation water.

A relatively large flow of water is directed into each strip during irrigation. The time it takes for the water to reach the
end of the field is the advance time. When the water is between 60 to 90 percent of the way down the strip, the water is shut off, and the water already in the strip continues to move down the strip. The time it takes for the water to recede from the soil surface (from the top of the strip to the bottom) is the recession time. To achieve a high DU, the advance time must be very similar to the recession time, resulting in a uniform IOT over the strip. G enerally, a border-strip system is designed and operated to have a small amount of tailwater, which requires a tailwater recovery system for reducing applied water. Border-strip systems can be designed to have a high DU and can achieve a high SAE, but only for a specific AD. Border-strip systems are well suited to crops with a constant deep r oot zone, such as alfalfa, pasture, trees,
and vines.

Technologies and actions for border-strip systems to optimize DUs and increase SAEs include: • Modify the advance rate to match the recession rate by adjusting the flow rate, changing border spacing, and using laser leveling to achieve a uniform slope and minimize cross slope. • Use a properly planned and designed tailwater recovery

system, and use the captured tailwater efficiently on the same field or on other irrigated fields.

Level Basin Systems

Level basin systems can be used on alfalfa, pasture, trees, vines, and field crops. The size of each basin is variable and depends upon soil infiltration rate and flow rate of water. Basins can vary from small (50 x 50 feet) to large (10 or more acres). There should be little or no slope within a basin. Earthen berms are built up on all sides of the basin. Water is delivered into each basin from pipelines and valves for smaller basins or from lined or unlined ditches with large gates. Normally, level basins are designed to have no tailwater. To achieve a high DU, the basin must be level, the flow of water must be high enough to cover the soil surface in a very short time (without any soil erosion from the flow), and the soil should be homogeneous.

Technologies and actions to optimize DUs and increase SAEs for level basin systems include: • Use laser leveling to achieve a precise grade. • Minimize soil variability within a basin. Large basins can

be subdivided into smaller basins with uniform soil
characteristics.T ECHNOLOGY I N W ATER M ANAGEMENT 5-8 The California Water Plan Update B ULLETIN 160-98



### Moisture content can also be estimated by dielectric sensors, devices that measure the dielectric content of
a soil. Plant stress indicator devices include pressure bombs and infrared thermometers. A pressure bomb is used to determine the turgor pressure within the cells of a plant’s leaf, which provides information on the plant’s moisture status. Infrared thermometers arehand-held devices used to measure plant canopy temperature. Plants can control water loss by regulating the stomatal openings in their leaves. Monitoring plantcanopy temperatures with this device aids in determining if crop stress is occurring, and can indicate the status
of soil moisture. Crop ET estimates are developed using either evaporation pans or weather information. Class A evaporation pans are commonly used for measuring evaporation. The pans, constructed of galvanized steelor aluminum, are situated in the center of a large irrigated turf area. The pan station includes devices tomeasure rainfall, temperature, wind speed, and relative humidity. Evaporation is measured by monitoringthe change in height of the water in the pan. The evaporation readings are multiplied by crop coefficients to estimate ET of a specific crop. Many growers use automated weather station datafor determining crop ET, such as the California Irrigation Management Information System. CIMIS is a

continued... Pressurized (Piped) Irrigation Systems Sprinkler Systems

Sprinkler systems are the most common type of pressurized systems and can be used for almost all crops. There are many different sprinkler head designs with flow rates that can vary from 10 gpm to less than 1 gpm. The spacing of the sprinkler heads in the field depends upon the flow rates and the radius of the area where the spray contacts the soil. To achieve high DUs, systems for field and truck crops are designed to space sprinkler heads close enough so that there is the proper amount of overlap of their wetted areas. Sprinkler systems for tree crops do not generally depend on overlap.

To achieve high DUs, a system must be designed to have minimal pressure variation, which ensures uniform flow rates from the sprinkler heads. Sprinkler nozzles must be maintained, because clogged or partially clogged nozzles lower DU, and worn nozzles will change flow rates, resulting in larger variations in pressure in the system. The application
rate must be the same or less than the soil’s infiltration rate. There are many variations in sprinkler systems used in
California.

Permanent Systems. Permanent systems use underground pipelines. Risers connect to an underground lateral, usually with a sprinkler head attached less than a foot from the surface. These systems are commonly used for orchard irrigation (under tree), but when connected to taller risers they can be
used for vines.

Solid Set Systems. Solid set systems use above ground aluminum pipelines, usually in 30 foot sections. Short risers connect the aluminum laterals to sprinkler heads. W ith a solid set system, the irrigation system covers a complete field. The system may stay in the field for the whole growing season, and be removed before harvest, or may be used only for germination or transplant establishment of vegetable crops. These systems are used mainly for field and truck crops. Hand Move Systems. Hand move systems are similar to the solid set systems, using the same aluminum pipelines, but do not normally cover a whole field. After an irrigation, the sprinkler laterals are disconnected from the sub-mains, and moved by hand to the next location in the field. After each irrigation, the laterals are systematically moved to the next location. These systems are usually designed for each part of the field to receive irrigation water every 7 to 14 days. These systems are used on field crops, truck crops, and
orchards.

Wheeled Systems. Wheeled systems have the lateral, risers, and sprinkler heads all mounted on wheels that can be moved throughout the field during the irrigation season. Side roll systems are designed to be stationary during the irrigation. After the irrigation, they are moved (using an on-board engine) to the next location.

Linear Move Systems. Linear move systems have the lateral, risers, and sprinklers mounted on pipes between large wheeled towers. The system continuously travels down the field during irrigations. The water is usually supplied to the system via a canal parallel to the travel of the system.

Center Pivot Systems. Center pivot systems are similar in structure to linear move systems, except instead of the lateral traveling down the field, it travels in a circle in the
field. One end of the lateral is fixed in the middle of the field, where the water enters the lateral. The entire lateral rotates around this pivot (which is usually a well), and continuously moves during irrigations.

Low-Energy Precision Application Systems. LEPA systems are similar to linear move sprinkler systems, except that they have drop tubes from the lateral to the soil surface instead of sprinkler heads. These systems are used in fields that have furrows, sometimes with small checks or dams in the furrow. The LEPA system travels perpendicularly to the furrows, and drop tubes emit water uniformly into the
furrows.T ECHNOLOGY I N W ATER M ANAGEMENT 5-9 The California Water Plan Update B ULLETIN 160-98



### repository of climatological data collected at 93 computerized weather stations throughout the State. CIMIS was developed by the Department and theUniversity of California at Davis, and has been in operation since 1985. Weather data are collected dailyfrom each weather station site and automatically transmitted to a central computer in Sacramento. Currently, the CIMIS computer receives over 25,000 requests for ET data annually, representing approximately 75,000 end users. The weather data (solar radiation, temperature, relative humidity, and wind speed) are used with a modified Penman equation to calculate
ET

o 

### . ET

o 

### is used in irrigation scheduling to estimate plant ET, by multiplying ET

o 

### by the appropriate crop or landscape coefficients.Regulated deficit irrigation is a technique to reduce crop ET. Irrigation is reduced during a specific stage of the crop’s growth, resulting in some crop stress at the time, but with little or no negative effects on production, quality, or on future growth. Research hasshown that this management technique may be applied to some tree crops such as pistachios, almonds, Technologies and actions for sprinkler systems to optimize
DUs and increase SAEs include: • Minimize pressure variation within the system. D esign

sprinkler heads, nozzles, and spacings for the proper amount of overlap in spray. Ensure that application rates are lower than the soil infiltration rate, and that filtration is adequate. The sprinkler system must be properly maintained. • To avoid spray losses, avoid irrigation during windy

conditions, and ensure that pressures and nozzles are compatible to avoid misting. • Where appropriate, use flow control nozzles.
Micro-Irrigation (Low Volume) Systems

Use of these systems increases each year. In many areas with trees and vines, they are the predominant method of irrigation. Low volume systems have many of the same components of sprinkler systems: pressurized water sources, filters, main pipelines, sub-mains, and laterals.
The main difference is the devices that emit the water to
the soil. These emit water at a very low flow rate (from 0.5 to 10 gallons per hour). There are two types of devices used, drip and micro-spray. With drip devices (emitters), water flows out as a constant stream (0.5 to 2 gallons per hour) directly
to the soil. W ith micro-spray, the devices (spray heads) produce a spray (4 to 20 gallons per hour) over the soil surface. Other key differences between micro-irrigation systems and sprinkler systems are that the entire main and sub-main pipelines are usually underground rigid plastic pipe, the laterals are flexible plastic hose, and the filters are designed to remove much smaller particles to prevent clogging. Emitter and spray heads use small orifices, channels, or nozzles to regulate flow rates, and are subject to clogging by particulate matter and biological growth. Drip system emitters are usually spaced 2 to 5 feet apart. Drip systems can be buried or placed on the soil surface. Emitter spacing is based upon the soil type being irrigated, with sandier soils needing a closer spacing, and clay soils using the greatest spacing. Drip systems are mostly used for orchards and vines, strawberries, and nurseries, but their use is increasing for vegetable crops. In these systems, the emitters are spaced much closer and are installed 8 to 18 inches below
the soil surface. Micro-spray systems use small plastic sprinklers or jets that spray water over the soil surface, creating a wetted area 12 feet or more in diameter. The droplet sizes are small comparedto a sprinkler system, and the application rate is low. Microspray heads are connected to plastic lateral hoses, usually one hose per row of trees. These systems are not designed to wet the entire soil surface like a typical sprinkler system. These systems are used almost exclusively in orchards. Drip and micro-spray systems can achieve high DUs if pressure variation is minimized. Because of the small nozzles and emitter pathways, partial or full clogging is always a potential problem, and can significantly reduce DU. These systems require regular maintenance to reduce clogging, including frequent flushing of pipelines and lateral hoses, and addition of chemicals (such as chlorine and acids) to kill bacteria and other biological growth and to reduce scale buildup. The systems require filtration and the filters need regular maintenance to ensure that they operate as designed. Achieving a high SAE with these systems is dependent on maintaining a high DU and on proper irrigation scheduling. One advantage to these systems is that irrigation scheduling is more easily controlled than most sprinkler and surface systems. Flow can be started and stopped easily (providing the water delivery system can accommodate this), and they are easier to automate, even to the extent of using remotely sensed field information for making irrigation timing decisions. Technologies and actions for optimizing DUs and increasing SAEs of micro-irrigation systems include : • Ensure that pressure variation within the system is

minimized, the filtration system is adequate, and prevent emitter clogging. • Perform regular inspections of filters, emitters/spray heads,

pressure levels, and tubing/pipelines, and provide regular maintenance, including filter cleaning and hose/pipeline flushing. • Where appropriate, use pressure compensating emitters or

microsprinklers.T ECHNOLOGY I N W ATER M ANAGEMENT 5-10 The California Water Plan Update B ULLETIN 160-98



### and olives. This irrigation strategy may have its greatest value in drought situations, where a grower may be forced to under-irrigate.

Water Treatment Technologies

As discussed in Chapter 3, water quality is a critical factor in determining the usability and reliability of any particular water source. Traditional public healthpractices emphasize the need to use best available quality sources for municipal supplies and to implement source protection measures to maintain high quality raw water sources. Where raw water supplies are of less than pristine quality, greater reliance must be placedon treatment technology. Water recycling and desalting are becoming larger components of potential future supplies, especially for urban areas. To transform theselower quality raw water sources into reliable water supply options, the basic water treatment technologies described in this section are used. Application of thesetechnologies to specific options (such as treating contaminated groundwater) is also outlined.

Description of Water Treatment Technologies
Activated Carbon Adsorption. Treatment by activated carbon adsorption is most applicable to organiccontaminants. By bringing contaminated water in contact with activated carbon in granular or powdered form, the contaminants are adsorbed onto the carbon. The process may be accomplished by batch, column,or fluidized-bed operations. Spent carbon may be regenerated or may be disposed of in accordance with regulatory requirements. In addition to the traditional
use of activated carbon for taste and odor control and dechlorination, carbon adsorption is widely used for removal of volatile organic chemicals and synthetic organic chemicals. Granular activated carbon adsorption is a unitprocess with a proven ability to remove a broad spectrum of organic chemicals from water. EPA considers GAC adsorption as the best available technology for
removal of VOCs and SOCs. Powdered activated carbon has traditionally been used to control taste and odor in water, and is also used for removal of certain SOCs, especially pesticides. PAC, in combination with conventional water treatment technology, can provideacceptable levels of pesticide removal in surface waters. A typical application of PAC would be for seasonal removal of pesticides found in municipal treatment plant raw water supplies during wet weather. Some limitations to use of PAC include the potential need for large doses of carbon to achieve desired levels oftreatment, and the resultant high sludge production. Air-Stripping. This treatment technique removes
VOCs from contaminated water. Countercurrent airstripping in a packed tower is the most commonprocess. The conventional configuration of a unit consists of a tower with water inflow at the top and air
inflow at the bottom. The tower is filled with small diameter random packing. As clean air moves upward, the VOCs transfer from the water phase into the air phase. Treated water exits from the bottom, and the air containing V OCs is discharged from the top of the tower, either into the atmosphere or into a gas

treatment system. Since air-stripping transfers contaminants to theatmosphere, they must take into consideration allowable VOC emissions. In some parts of the State, suchas in the South Coast Air Quality Management District, emissions are strictly regulated and additional treatment to reduce emissions to acceptable levels isneeded. GAC adsorption may be used with air-stripping to control emissions from a packed-tower aeration

system.The closed-loop air-stripping process is an innovative extension of the traditional air-strippingtechnology. The closed-loop air-stripping process combines air-stripping with an ultraviolet photo-oxidation An evaporation pan with weather station in the background.T ECHNOLOGY I N W ATER M ANAGEMENT 5-11 The California Water Plan Update B ULLETIN 160-98

This air stripping system at
McClellan Air Force Base in Sacramento is being used to clean groundwater
contaminated with solvents.



### process to control VOC emissions. In this process, exhaust air is irradiated with UV radiation in a photo-oxidation chamber, and VOCs are destroyed. The end products are carbon dioxide, hydrochloric acid, and ozone. The treated air is recycled to the PTA

unit. Advanced Oxidation. In contrast to GAC or airstripping, advanced oxidation processes can destroy organic contaminants rather than transferring themfrom one medium to another. Examples of AOPs include treatment with UV, ozone/hydrogen peroxide,and ozone/UV. AOPs provide more powerful oxidation and at faster rates than conventional oxidants such as chlorine. As a result, they can remove compounds
which are not treatable with conventional oxidants.These oxidants can also reduce disinfection by-products created by processes such as chlorination. To date,much AOP work has focused on removing low-molecular weight solvents such as TCE and PCE from contaminated groundwater, and on reduction of DBPs. Membrane Technologies. Membrane technologies include reverse osmosis, electrodialysis, microfiltration, ultrafiltration, and nanofiltration. RO, MF, UF, and NF are pressure-driven processes of barrier separation;electrodialysis employs electrical potential as the driving force. Membrane processes have been used fordesalting, removal of dissolved organic materials, softening, liquid-solid separation, pathogen removal, and heavy metals removal. Other promising membrane technologies are membrane phase-contact processes. These processes are not pressure driven but remove contaminants by extraction into another phase, as do air-stripping and solvent extraction. RO membranes permit water to flow throughthem while rejecting the passage of dissolved contaminants. This is based on the natural osmotic processwhere water passes through a semipermeable membrane from a solution of higher concentration to alower one. In RO, a pressure greater than osmotic pressure is applied to the contaminated water. Water passes through the membrane but contaminants are retained. RO systems using newer membranes operate at about 250 psi for desalting brackish groundwater and up to 1,000 psi for seawater desalting.Electrodialysis induces contaminant ions to migrate through a membrane, removing them from the water. In an electrodialysis unit, contaminated wateris pumped into narrow compartments separated by alternating cation-exchange and anion-exchangemembranes, selectively permeable to positive and negative ions. A variation of this process is called electrodialysis reversal. In electrodialysis, the electrical current flow is always in the same direction. In EDR, the electrical polarity is periodically reversed, which reverses ion movement and flushes scale-forming ions
from the membrane surfaces. MF, UF, and NF operate similarly to RO, but atlower pressures. More stringent drinking water regulations coupled with diminishing sources of pristine
waters have stimulated interest in the use of membrane technologies in drinking water treatment. The use of low-pressure membrane filtration for municipal watertreatment is a relatively new concept in the water industry, which has traditionally used membranes for removing salts or organic materials. MF operates at pressures ranging from 20 to 100 psi and is capable ofT ECHNOLOGY I N W ATER M ANAGEMENT 5-12 The California Water Plan Update B ULLETIN 160-98



### removing micron-sized (10 -6 

### m ) materials. Colloidal particles are physically rejected by MF membranes. UF operates at pressures ranging from 3 to 150 psi and is capable of removing materials that are on the order of a nanometer in size (10 -9 

### m) from water. Dissolved inorganic contaminants are not retained by MF and UFmembranes. One of the most novel applications of lowpressure membrane technology is the removal of microorganisms such as coliform bacteria, viruses, giardia, and cryptosporidium from drinking water sources without using chemicals for primary disinfection. The efficiency of low-pressure membranes in removing particles from untreated water supplies has been well documented. MF and UF have shown to be capable of consistently reducing turbidities to less than 0.1 NTU, regardless of the influent turbidity level. NF operates at pressures ranging from 150 to 300 psi and has characteristics between those of RO and MF. The capital cost of an NF plant is typicallyhigh compared to conventional treatment plants because of the cost of membranes and high-pressureequipment. Pilot and bench-scale studies have demonstrated that nanofiltration is effective in removing DBP precursors and SOCs such as pesticides. NF is also frequently used for water softening applications. Ion-Exchange. The process passes contaminated water through a packed bed of anion or cation resins. The resin type is selected based on the contaminant to be removed. The treatment process exchanges ionsbetween the resin bed and contaminated water. By displacing ions in the resin, contaminant ions become part of the resin and are removed from process water.During the ion-exchange process, the exchange capacity of the resin becomes depleted and needs regeneration to become effective. Sodium chloride brine is used to regenerate the resin. Ion-exchange is widely used for removing nitrates in groundwater and for removing some metals. It may also be used for water softening. Its effectiveness in removing radionuclidesis being investigated in a number of full scale applications. Chemical Precipitation . Chemical precipitationis used for removing heavy metals from water. The contaminants are precipitated from solution and removedby settling. There are several types of chemical addition systems including ones using carbonates, hydroxides, and sulfides. The carbonate system uses soda ash and pH adjustment. The hydroxide system is most widely used for removing inorganics and metals. The system uses lime or sodium hydroxide to adjust the pH upward. The sulfide system removes most inorganics (except arsenic). The disadvantage is that sulfide sludges are susceptible to oxidation to sulfate when exposed to air, resulting in resolubilization of
the contaminants. Biological Treatment. Biological treatment uses microorganisms to remove contaminants in waterthrough metabolic processes. The process can be a suspended growth system, where the microorganisms and
nutrients are introduced in an aeration basin as suspended material in a water-based solution, or a fixed-film system where the microorganisms attach to a medium which provides inert support. Biological treatment is used in municipal wastewater treatment and for treating water containing organic compounds such as petroleum hydrocarbons. Biological treatment is often used for remediation of leaking fuel tank sites, either above ground, or in situ

. Disinfection. This treatment inactivates pathogens in water. The most common disinfection process ischlorination, often used to treat wastewater and drinking water. Two relatively new disinfection processes applied in water recycling include UV radiation and ozonation. UV has recently been approved by the DHS for disinfecting recycled water. UV has been shown to be as effective as chlorine or ozone in reducing coliform
bacteria and is more effective at virus removal. UV has the potential to be more cost effective than chlorine disinfection, and eliminates the DBPs and handling
hazards associated with chlorination. Innovative Treatment Technologies. Many innovative technologies are being used to treat contaminated groundwater at hazardous waste sites. These technologies typically combine basic processes with a fewspecial techniques. In the future, these technologies may see broader application in groundwaterrecovery projects. Some examples of these technologies, primarily those applied at pilot or full scales, are
covered below.The EnviroMetal Process, a proprietary technology, treats groundwater in situ using reactive metal (usually iron) to enhance the abiotic degradation ofdissolved halogenated organic compounds. A permeable treatment wall of the coarse-grained reactivemetallic media is installed across a plume of contaminated groundwater, breaking down contaminants as they migrate through the aquifer. This technology hasreceived regulatory approval for use in at least two industrial facilities in California for treating shallow plumes with elevated levels of VOCs.T ECHNOLOGY I N W ATER M ANAGEMENT 5-13 The California Water Plan Update B ULLETIN 160-98



### Integrated vapor extraction and steam vacuumstripping removes VOCs, including chlorinated hydrocarbons, in groundwater and soil. The integrated system has a vacuum countercurrent stripping tower that uses low-pressure steam to treat contaminated groundwater, and a soil vapor extraction process to treatthe soil. The stripper and the soil vapor extraction systems share a GAC unit to decontaminate the combinedvapors. The technology has been used to treat TCEcontaminated groundwater and soil. Steam-enhanced extraction uses injection wells toforce steam through the soil to enhance vapor and liquid extraction thermally. The process extracts volatileand semivolatile organic compounds from contaminated soil and groundwater. The recovered contaminants are condensed or trapped by activated carbon filters. After treatment is complete, subsurface conditions are suitable for biodegradation

.Subsurface volatilization and ventilation technology uses a network of injection and extraction wells to treat subsurface organic contamination through soil vapor extraction and in situ biodegradation. A vacuum pump extracts vapors while an air compressor injects air in the subsurface. In most sites, extraction wells are placed above the water table and injection wells areplaced below the groundwater level. Because it provides oxygen to the subsurface, the process can enhance

in situ bioremediation.The PACT wastewater treatment system is a proprietary technology that combines biological treatmentand PAC adsorption to contaminated water. Microorganisms and PAC contact wastewater in an aeration
tank. The biomass removes biodegradable organiccontaminants, and PAC enhances adsorption of organic compounds. PACT systems treating up to 53 mgd of wastewater are in operation. This process isapplicable to groundwater contamination from hazardous waste sites.Capacitive deionization desalting is an experimental process being researched at Lawrence Livermore National Laboratory. It involves passing water through electrodes made of carbon aerogel and generating a small voltage differential between alternating positive and negative electrodes, thus drawing ions out of thesolution. The ions are removed by electrostatic attraction and are retained on the electrode until the polarity is reversed. The ions are then captured with a small
amount of water. Other dissolved materials such as trace metals and suspended colloids are removed by electrodeposition and electrophoresis. The process has been operating in a laboratory for over two years. Sodium chloride, sodium nitrate, and ammonium perchlorate solutions have been tested with excellentresults. Electrode life has been acceptable in the laboratory, with electrodes operating for more than two years with little degradation. The electrodes appear tobe regenerable with little loss of capability. Energy requirements appear less than current desaltingtechnologies. Field testing has begun in Northern California, and will later be moved to Southern California.

Application of Water Treatment Technologies Water Recycling. Recycled water uses includegroundwater recharge, agricultural and landscape irrigation, wildlife habitat enhancement, industrial use,and recreational impoundments. Groundwater recharge and agricultural and landscape irrigation constitute the greatest uses of recycled water in theState. Table 5-2 lists some water recycling plants having a capacity of at least 10 mgd. Indirect potable reuse of recycled water has beenpracticed for years through groundwater recharge programs. In Los Angeles County, the Montebello Forebay Groundwater Recharge Project began recharging the Central Basin aquifer with recycled water in 1962. Currently up to 60 taf/yr of recycled water percolatesinto the groundwater basin, from which it is later extracted for distribution in potable water systems. Water Factory 21 in Orange County and the West Basin Water Recycling Facility have been producing advanced treated recycled water for seawater intrusion barrierinjection, with the majority of the injected water entering the groundwater and becoming part of the water supply. As advanced treatment technologies become morecost-effective, and as public acceptance increases, augmentation of surface water supplies may become another application for recycled water. The San Diego water repurification program, discussed in the sidebar,would be the first example of planned, indirect potable reuse where repurified water is discharged directlyinto a surface reservoir without percolation or injection into groundwater. (Unplanned, indirect potable reuse occurs whenever treated effluent is dischargedinto a waterway upstream of another user’s water supply intake.) Reservoir retention allows for additionalmonitoring of the repurified water prior to introduction to a potable water supply. Surface water supplyaugmentation projects are approved by DHS on a caseby-case basis.T ECHNOLOGY I N W ATER M ANAGEMENT 5-14 The California Water Plan Update B ULLETIN 160-98

T

ABLE 5-2 Water Recycling Plants with a Capacity of at Least 10 mgd

Name Capacity Treatment Process Type Of Reuse Annual Supply (mgd) a (taf)

San Jose Creek Water Reclamation Plant (Los Angeles County Sanitation District) 100 Primary sedimentation, activated sludge, coagulation, filtration and
chlorination Groundwater recharge, agricultural and landscape irrigation, and nursery stock irrigation 43.2

Donald C. Tillman Water Reclamation Plant (City of Los Angeles) 80 Primary sedimentation, activated sludge, coagulation, filtration, chlorination, and
dechlorination Recreational lake, wildlife lake, and Japanese garden 20.0

Fresno-Clovis Metropolitan Area Regional Wastewater
Facilities 60 Primary sedimentation, trickling filter, and activated sludge Agricultural irrigation 13.7

Los Coyotes Water Reclamation Plant (Los Angeles County Sanitation District) 37 Primary sedimentation, activated sludge, coagulation, filtration, and chlorination Landscape irrigation, industrial reuse (process water, concrete mix, and dust control), and crop irrigation 5.9

West Basin Water Recycling Facility (West Basin Water District) 37 Coagulation, filtration,
clarification and reverse osmosis (5 mgd),
microfiltration and reverse osmosis (2.5 mgd) Industrial use, landscape irrigation, and seawater
intrusion barrier 8.4

Chino Basin Municipal Water District Regional
Plant No. 1 32 Activated sludge, coagulation, filtration, chlorination, and
dechlorination Landscape irrigation and
recreational lakes 1.7

Terminal Island Treatment Plant (City of Los Angeles) 30 Primary sedimentation, activated sludge, filtration, reverse osmosis, and
microfiltration Seawater intrusion barrier and
industrial use 0 b

Salinas Valley Reclamation Plant (Monterey Regional
Water Pollution Control Agency) 30 Primary sedimentation, trickling filters, coagulation, filtration, and disinfection Agricultural irrigation 13.2

Long Beach Water
Reclamation Plant 25 Primary sedimentation, activated sludge, coagulation, filtration, and disinfection Landscape irrigation, nursery irrigation, and repressurization of oil-bearing strata 5.1

City of Modesto Wastewater Quality Control Facility 25 Primary sedimentation, trickling filter, oxidation ponds, and chlorination Fodder crop irrigation 14.4 City of San Diego North City Water Reclamation
Plant 30 Primary sedimentation, activated sludge, coagulation, filtration, and chlorination Landscape irrigation 3.0

Central Contra Costa Sanitary District Water
Reclamation Plant 25 Primary sedimentation, activated sludge, UV disinfection, coagulation, filtration, and chlorination Landscape irrigation, and light
industrial 1.2T ECHNOLOGY I N W ATER M ANAGEMENT 5-15 The California Water Plan Update B ULLETIN 160-98

T

ABLE 5-2 Water Recycling Plants with a Capacity of at Least 10 mgd (continued)

Name Capacity Treatment Process Type Of Reuse Annual Supply (mgd) a (taf)

Laguna Treatment Plant (City of Santa Rosa) 18 Primary sedimentation, activated sludge, coagulation,
filtration and chlorination Fodder irrigation 9.3

Fairfield-Suisun Subregional
Wastewater Treatment
Plant 17 Activated sludge, coagulation, filtration, chlorination, and
dechlorination Sod farming and duck hunting marsh maintenance 2.4

Michelson Water Reclamation Plant (Irvine Ranch Water District) 17 Primary sedimentation, activated sludge, coagulation, filtration, and chlorination Landscape irrigation, nursery irrigation, and toilet flushing 8.2

Whittier Narrows Water Reclamation Plant (Los Angeles County Sanitation District) 15 Primary sedimentation, activated sludge, coagulation, filtration, and chlorination Groundwater recharge and nursery stock watering 9.4

San Jose/Santa Clara Water
Pollution Control Plant 15 Activated sludge, filtration
and chlorination Landscape irrigation and industrial processes 7.5 Los Angeles-Glendale Water Reclamation Plant (City of Los Angeles) 20 Primary sedimentation, activated sludge, coagulation, filtration, chlorination, and
dechlorination Landscape irrigation and
industrial reuse 3.3

City of Bakersfield
Wastewater Treatment Plant

No. 2 19 Primary sedimentation and oxidation ponds Crop irrigation 16.8

Pomona Water Reclamation Plant (Los Angeles County Sanitation District) 13 Primary sedimentation, activated sludge, coagulation, filtration, and chlorination Agricultural irrigation landscape irrigation, and industrial process 12.5

City of Visalia Water
Conservation Plant 12 Primary sedimentation, trickling filter, activated sludge, and chlorination Non-food crop irrigation 4.9

Valley Sanitary District
Wastewater Treatment Facility (Riverside County) 12 Primary sedimentation, trickling filter, activated sludge, and oxidation ponds Non-food crop irrigation 4.3

City of Bakersfield
Wastewater Treatment Plant
No. 3 12 Primary sedimentation, trickling filter Agricultural irrigation 11.6

Desert Water Agency
Wastewater Reclamation Facility (Riverside County) 10 Coagulation, filtration, and
chlorination Landscape irrigation 2.7

Water Factory 21 (Orange County Water District) 10 Coagulation, sedimentation, filtration, carbon adsorption (5 mgd), reverse osmosis (5 mgd), and disinfection Groundwater injection for
intrusion barrier 2.6

Lancaster Water Reclamation Plant 10 Primary sedimentation, oxidation ponds, and
chlorination Wildlife refuge and fodder irrigation 9.7

a One mgd equals 1,120 af/yr

b Expected to operate by 2000 with annual supply of 19 tafT ECHNOLOGY I N W ATER M ANAGEMENT 5-16 The California Water Plan Update B ULLETIN 160-98



### The California Potable Reuse Committee was formed in 1993 to study the viability and safety of indirect potable reuse. The committee, commissioned by DHS and the Department, developed six criteriathat must be met before indirect potable reuse is allowed for augmentation of surface water supplies. (DHS has other proposed regulations and criteria for indirect potable reuse through groundwater recharge projects.) The criteria are: (1) Application of the best available technology in
advanced wastewater treatment with the treatment plant meeting operating criteria. Best available technology must include a membrane component with the functional equivalency of reverse

osmosis. (2) Maintenance of appropriate reservoir retention times based on reservoir dynamics. (3) Maintenance of advanced wastewater treatmentplant reliability to consistently meet primary microbiological, chemical, and physical drinking
water standards. (4) Compliance with applicable State criteria forgroundwater recharge for direct injection of recycled water.(5) Maintenance of reservoir water quality. In addition to meeting drinking water standards, recycled water used for reservoir augmentation shall be ofequal or better quality than that in the storage reservoir on a constituent-by-constituent basis. (6) Provision for an effective source control program. The source control program is to include pretreatment/pollution prevention measures that prohibit the discharge of any substance which, whether
alone or in combination with other wastewater constituents, causes or threatens malfunction orinterference with the wastewater treatment process, constitutes a hazard to human health or safety, or affects the water quality of the potable storage

reservoir.Treatment criteria for reuse of municipal wastewater are mandated in Title 22 of the California Code of Regulations. These criteria specify the treatmentlevel for specific reuse applications. Treatment technologies used for water recycling depend on the reuse application. For most nonpotable reuse applications at least secondary treatment is required. To achieve secondary treatment, conventional biological treatmentprocesses such as activated sludge process, trickling filters, or oxidation ponds are used, followed by
sedimentation and disinfection with chlorine. Tertiary treatment, which is often standard for recycled water, is achieved by adding a filtration step after secondary treatment and before final disinfection. Two major types of filtration technology are applied in tertiary treatment plants: conventional and direct filtration. Conventional filtration, as defined in Title 22, includes coagulation, sedimentation, and filtration
to condition the water. Conventional filtration technology requires that the filters be backwashed toprevent turbidity breakthroughs. The Title 22 backSan Diego Water Repurification Program

The City of San Diego, in conjunction with the San Diego County Water Authority, proposes to repurify 16 taf/yr of wastewater for indirect potable purposes. R esults of pilot studies conducted by the agencies show that wastewater can be repurified to a level suitable for human consumption. The agencies would construct an 18 mgd wastewater repurification facility using state-of-the-art technology to treat recycled water from the City of San Diego’s North City Water Reclamation Plant. The repurified water would be transported over 20 miles to the 90 taf San Vicente Reservoir, where it would be blended with imported raw water supplies and stored for a period of time. The blended water would eventually be conveyed via the existing El M onte Pipeline to the city’s Alvarado Filtration Plant for traditional treatment before being delivered to the city’s drinking water system.

Repurified water is based on a concept of multiple barriers. Recycled water from the North City Water Reclamation Plant, treated to levels acceptable for landscape irrigation and for other nonpotable purposes, would be treated further at the proposed 18 mgd wastewater repurification facility. The repurification process would include subjecting the recycledwater to four more treatment processes — low-pressure microfiltration, reverse osmosis, ion-exchange, and ozonation. These treatment processes, while redundant in their functions,

ensure r eliability of the overall repurification system and produce an end product that would exceed current health and safety standards.

Pilot studies show that the City of San Diego could turn recycled water into an alternative drinking water source. The city is preparing an environmental document and has begun design of the project. The project is expected to begin operation in late 2002.T ECHNOLOGY I N W ATER M ANAGEMENT 5-17 The California Water Plan Update B ULLETIN 160-98



### wash requirements result in an equipment-intensive process. Direct filtration provides a cost-effective andconvenient tertiary technology when secondary effluent quality is high. The technology will likely be incorporated in areas where effluent from residentialareas provides the process water. Newer water recycling facilities use direct filtration as part of the tertiarytreatment process. Direct filtration bypasses the sedimentation step. Continuously backwashed directfiltration technology is available, minimizing equipment needs. Achieving the maximum use of tertiary treatedwater for landscape irrigation and other outdoor applications depends on the ability to store the treatedwater supply when it is not needed. Landscape irrigation demands, for example, have a wide seasonalvariation in the State’s inland areas. (Landscape irrigation demands also vary diurnally, with most sites demanding recycled water at night when supplies are at their lowest levels.) Groundwater recharge is often acost-effective solution to meeting seasonal demand patterns, allowing the storage of relatively large quantities of recycled water without the capital cost investment associated with above-ground reservoirs. Desalting. According to the International Desalting Association’s inventory of worldwide desaltingplants, the United States is second in usage of desalting in the world, with almost 1 maf/yr of installedcapacity. (Only Saudi Arabia has more installed capacity.) In 1985, the United States had less than 7 percent of the world’s capacity; by 1993, that figure had risen to nearly 15 percent. Common feedwater sourcesfor desalting plants include brackish groundwater, municipal and industrial wastewater, and seawater. Costsof desalting increase with increasing feedwater salinity. Table 5-3 lists some larger desalting plants in
California. Reverse osmosis accounts for 89 percent of theinstalled capacity of desalting plants in California, including all the significant plants supplying municipalwater supplies or recycling municipal wastewater. Reverse osmosis is likely to continue to dominate in California, given recent improvements in membrane performance. Reverse osmosis membranes have changed greatly in the last 20 years. Membranes are available to serve many purposes. This allows water suppliers to select and operate membranes specificallysuited to the feedwater quality and the required product water quality. Membranes have developed into two principal classes.
The first class is the traditional reverse osmosis membrane which rejects all salt ions (as well as other dissolved constituents) equally. This process, also called hyperfiltration, is used on water requiring the
removal of all classes of dissolved constituents. The
second class of membrane processes is represented byMF, UF, and NF. For example, nanofiltration membranes reject larger dissolved ions such as calcium and T

ABLE 5-3 Sample Desalting Plants

Site Owner Capacity Comments (mgd) a Brackish Water Desalting Arlington Santa Ana Watershed 6.0 Operational Project Authority Tustin City of Tustin 3.0 Operational Oceanside City of Oceanside 2.0 Operational, being expanded West Basin West Basin MWD 1.5 Operational

Wastewater Desalting Water Factory 21 Orange County WD 5.0 Operational, being expanded West Basin West Basin MWD 5.0 Operational, being expanded to 7.5 mgd San Diego City of San Diego 1.0 Operational

Seawater Desalting Santa Barbara City of Santa Barbara 6.7 Standby as drought reserve Morro Bay City of Morro Bay 0.6 Standby as needed Marina Marina Coast Water District 0.3 Operational Santa Catalina Island Southern California Edison 0.1 Operational

a One mgd equals 1,120 af/yrT ECHNOLOGY I N W ATER M ANAGEMENT 5-18 The California Water Plan Update B ULLETIN 160-98



### sulfate, along with equally large dissolved feedwater constituents. When used in a water softening role, they will remove calcium, magnesium, and sulfate from water, but allow sodium and chloride ions to pass through. Nanofiltration membranes are often used for water softening. Advances in membrane technology have reduced operating pressures, increased flow rates, and increased salt rejection in typical reverse osmosis applications—thereby reducing treatment costs. As operating pressures have decreased, so have energy costs. Energy requirements have accounted for at least 50 percent or more of the operating costs of a reverse osmosis plant.
New membrane materials have allowed more membrane area per module and higher productivity per square foot. Increased productivity of membranes and their longer life expectancy reduces the capital cost of the plant, reducing the cost of water. Increasing salt rejection provides better water quality. In the case of groundwater desalting, the high purity product water
can be blended with raw water to meet the desired overall product water quality.

Treatment of Contaminated GroundwaterThe selection of technologies for treating groundwater contamination depends on site conditions and the contaminants to be removed. Although there are a variety of options, no one technology is necessarily capable of responding to all conditions found at a groundwater contamination site. In practice, treatment technologies are sometimes used in combination to remediate contamination. For example, groundwatercontaminated with nitrates and pesticides requires ionexchange technology to remove the nitrates and GACadsorption to remove the pesticides. Table 5-4 provides some examples of contaminated groundwatertreatment sites. Treatment unit capacities at the locations shown range from 0.3 mgd to 4.1 mgd. Some local agencies have integrated groundwater treatment plants into municipal distribution systems. The West Basin Municipal Water District for example,constructed a 1.5 mgd facility that uses reverse osmosis technology to remove elevated levels of dissolvedsolids from contaminated groundwater. The plant supplies about 1.5 taf annually of recovered groundwater to the district for municipal use and to Dominguez Water Corporation for municipal and industrial uses. The Glenwood nitrate water reclamation plant, owned by Crescenta Valley County Water District, is a 3.7 mgd ion-exchange treatment plant. Treatedgroundwater from the plant is sold to Foothill Municipal Water District and MWDSC for municipal and industrial uses. The plant’s eventual project yield willbe about 1.6 taf annually. The City of Pomona operates a 15 mgd ion-exchange treatment plant, treating nitrate-contaminated groundwater from the Chino Groundwater Basin. At full capacity, the treatment plant supplies about two-thirds of the city’s municipal
water demand.Some aquifers in California are contaminated beSeawater Desalting–
Marina Coast Water District

Marina Coast Water District is the primary water supplier for the City of Marina. MCWD relies on the Salinas Valley groundwater basin as its primary water supply source, as do other Salinas Valley urban and agricultural water suppliers.
Overdraft of the Salinas Basin has caused seawater from Monterey Bay to migrate into two of the three aquifers underlying the coastal part of Salinas Valley. Seawater intrusion has rendered some groundwater unfit for use. MCWD has had to replace shallower wells with deeper wells to meet demands for potable water. MCWD investigated ways to diversify its water supply sources because of potential groundwater extraction limitations, and chose desalting as its preferred option.

MCWD completed construction of a reverse osmosis seawater desalting plant in 1997. The plant produces approximately 300,000 gpd of potable water (equivalent to 340 af/yr), and uses beach wells for seawater intake and brine disposal. A shallow production well drilled into beach deposits near MCWD’s water treatment plant provides intake water for the desalting plant. Using a beach well to supply seawater minimizes the need for extensive pretreatment. Beach sands filter most of the suspended material in the seawater. The reverse osmosis system is a single stage system operated at 40 to 45 percent

recovery rates.

The project produces a reject brine flow of about 450,000 gpd. An injection well in a shallow sand aquifer is used to dispose of the brine. Power requirements for the desalting plant are estimated at 5,000 kWh of electricity per acre-foot of water produced, or about 15 kWh for each 1,000 gallons of desalted water. Total capital costs for the desalting plant were about $2.5 million.T ECHNOLOGY I N W ATER M ANAGEMENT 5-19 The California Water Plan Update B ULLETIN 160-98



### cause of past hazardous waste disposal practices. Anumber of these sites are undergoing remediation. Carbon adsorption, membrane filtration, air stripping, advanced oxidation processes, biological treatment,chemical precipitation, and innovative treatment technologies are examples of technologies used. Forexample, Aerojet General Corporation’s manufacturing facility in Rancho Cordova operates a 6.5 mgd groundwater treatment facility which removes VOCsfrom the groundwater. The treatment facility has airstripping towers and GAC adsorption units. Treated groundwater is reinjected into the aquifer through wells, and is also recharged via surface impoundments. Another example is Valley Wood Treating Company in Turlock, which uses pump-and-treat and in situ treatment techniques for chromium-contaminated groundwater. The company pumps groundwater and uses chemical precipitation for first stage contaminant removal. Next, a reducing agent is added to the treated water, which is then reinjected into the aquifer. The resulting reaction reduces chr omium in situ and subsequently fixes residual chromium in the soil.

Water Supply/Flood Control Technologies

Inflatable Dams
Inflatable rubber, or fabric and rubber, dams and tubes have been used for years as weirs to impound water for water supply and flood control. Inflatable dams were developed and first used in the 1950s in the Los Angeles area. They were typically inflated with water. Since that time, construction materialsand control systems have been improved and features have been added, such as fins to reduce vibrations during overflow. Air is now the preferred inflation medium. The manufacturers report that there are about 1,900 of these dams worldwide, with 50 in the United States. Alameda County Water District’s Rubber DamNo. 3 is a representative example of a modern inflatable dam. The 13-foot-high, 375-foot-long dam was T

ABLE 5-4
Examples of Contaminated Groundwater

Treatment Sites

Location Contaminant Treatment

Lodi DBCP GAC Lodi Pathogens UV
Modesto DBCP GAC Modesto Nitrates Electrodialysis

Fresno DBCP GAC Fresno TCE Air-stripping
Clovis DBCP GAC Monrovia TCE Air-stripping Monrovia VOCs Air-stripping San Gabriel Valley VOCs GAC

Remediation of Nitrate Contamination– City of McFarland

The City of McFarland in Kern County has a population of about 7,650 people. McFarland Mutual Water Company supplies municipal water. The company depends on groundwater for raw water supply and has four active wells.

Elevated levels of nitrates in MMWC’s water were detected in the early 1960s. Many wells sampled showed nitrate levels exceeding the drinking water standard. Studies identified fertilizer application on agricultural lands as a major contributor to nitrates in the groundwater. MMWC abandoned two of its wells due to nitrate contamination and provided treatment for two wells to reduce nitrate levels to meet drinking water standards. Two deeper replacement wells were constructed to extract groundwater unaffected by nitrate or pesticide

contamination.

In 1978, the MMWC received an EPA grant to study groundwater treatment alternatives, leading to the 1983 construction of a 1 mgd ion-exchange treatment plant. A second 1 mgd ion-exchange treatment plant for another well was constructed in 1983. The two wells supply about 20 af annually of treated water to McFarland and adjoining rural areas within
the MMWC service area.

The plants’ designs rely heavily on technology and practices used in the water softening industry. Plant location was dictated by the existing wells and distribution systems. Because there was no centralized distribution system, the plants had to be designed to operate from a single well. Well pumps operate on a demand basis, so the plants had to be able to operate automatically. The system was designed to accept water directly from the well, treat for nitrate removal, and allow treated water to flow directly into the distribution system. The ability of the process to adapt to quick start-up and frequent on-off operation was an important consideration in choosing it over reverse osmosis and biological treatment methods.T ECHNOLOGY I N W ATER M ANAGEMENT 5-20 The California Water Plan Update B ULLETIN 160-98



### constructed in 1989 on Alameda Creek in the City of Fremont. The dam impounds a 154 af reservoir for direct groundwater recharge and diverts flows into adjacent spreading grounds in former aggregate pits.
The air-inflated dam is bolted to a reinforced concrete
slab that was constructed across the stream channel. To clear the leveed channel for flood flows, the dam isdeflated by district personnel, or it automatically deflates slowly when overtopped by substantial flows. The
dam is reinflated when stream flows subside to safe levels and any water-borne debris has passed the dam.These operations are much easier and safer than alternatives such as installing, tripping, and reinstalling hinged flashboards. A similar inflatable dam has been used in the Russian River at Mirabel since 1976, where water is diverted to percolation ponds. The San Gabriel, Los Angeles, and Santa Ana River
Basins also have similar devices. OCWD installed two large air inflatable rubber dams across the Santa Ana River (Imperial Highway Dam in 1992 and Five Coves Remediation of Volatile Organics
Contamination–McClellan Air Force Base

In 1981, McClellan AFB initiated soil and groundwater investigation as part of a Department of Defense program to identify and evaluate suspected contamination at military
installations nationwide. Groundwater contaminants identified included VOCs, SVOCs, petroleum hydrocarbons, and trace heavy metals. Subsequent investigations revealed that contaminants had migrated off the base. At least one municipal well was abandoned because of contamination. In 1986 and 1987, 500 homes with private domestic wells to the west of the base were connected to the City of Sacramento’s

water system.

In 1987, groundwater extraction and on-site treatment began. The treatment involved an air stripper, with incineration and caustic scrubbing of the air stream, followed by carbon adsorption and biological treatment of the effluent. The treatment plant had a capacity of 1.44 mgd and discharged its treated water to Magpie Creek and to a wetland area under permits from the Central Valley RWQCB. Later, the biological treatment unit was removed when the concentration of ketones was low enough to be removed by the air stripper and carbon adsorption units.

In 1996, the air stripper and incinerator were replaced with a UV/ hydrogen peroxide system to remove volatile organics.
The GAC is still in use. O perating and maintaining the new system is less expensive than the air-stripping and incinerating process, and the higher treatment efficiency reduces carbon use in the GAC units. Several more years of extraction and treatment of the groundwater will be required before the contaminated aquifer is restored to usable quality.

Remediation of Pesticide and Fertilizer
Contamination–Occidental Chemical Manufacturing Facility

In the late 1970s, pesticide and fertilizer contamination was discovered in soil and groundwater at the Occidental Chemical Agricultural Products manufacturing facility near Lathrop. The primary contaminants found were dibromochloropropane, ethylene dibromide, and sulfolane. OxyChem removed or capped contaminated soil at the facility in 1981 and 1982. The groundwater remediation program began operation in 1982 and continues today. The original groundwater restoration system was designed to remove DBCP and EDB to 1 ppb. It consisted of five extraction wells, a 500 gpm treatment system, and two wells for deep injection of treated groundwater into an unusable confined aquifer. Sulfolane was not removed from the groundwater, but its injection to the aquifer was considered acceptable since the aquifer was designated unusable for domestic or agricultural purposes. SWRCB Resolution No. 88-63 in 1988, a 1989 revision of MCLs for DBCP and EDB, and a 1989 DHS maximum allowable level for sulfolane in municipal water resulted in more stringent treatment requirements. OxyChem made operational changes in the treatment system and added a biological treatment system in 1992 (microbial inoculation of the carbon treatment system) to remove sulfolane from the groundwater to comply with the new treatment standards of 0.2 ppb DBCP, 0.02 ppb EDB, and 57 ppb sulfolane. Two extraction wells were added, increasing treatment capacity to 600 gpm.

The groundwater restoration system was designed to treat the contaminated groundwater and to control the hydraulic gradient in order to prevent off-site migration of the contaminants. Several dozen monitoring wells were built to monitor the effectiveness of the system. Monitoring reports
have shown reductions of contaminant concentrations and control of contaminant plume. However, it is anticipated that groundwater remediation will continue for many years.T ECHNOLOGY I N W ATER M ANAGEMENT 5-21 The California Water Plan Update B ULLETIN 160-98

This inflatable dam is owned by Alameda County Water District.

### Dam in 1993) to divert flows into groundwater recharge basins. The dams are deflated when flows exceed 1,000 cfs.
Other uses of inflatable dams have evolved. In 1988, PG&E replaced flashboards on its Pit No. 3 dam on the Pit River with 6-foot-high inflatable dams. USBR recently replaced two 18-foot-high by 100- foot-long drum gates on the crest of Friant Dam with Obermeyer gates. The gates are steel panels connected to the dam crest by hinges along theirupstream edge, and are raised and lowered by airinflated bladders. D uring the flood of January 1997, an inflatable rubberized berm was installedon the water side of the Sutter Bypass levee to provide the additional height needed to protect the levee from overtopping. Rubber berms of this type are used as cofferdams during constructionprojects in wet environments or as pollution containment devices.

Weather Modification

Since the early 1950s, California water users have practiced cloud seeding to augment precipitation, mostly along the western slopes of the Sierra Nevadaand along the Coast Range. In 1996, there were 14 active cloud seeding programs operating in California. The goal of these programs is to increase water supply for hydroelectric power generation and for agriculturaland municipal uses. Cloud seeding programs have potential legal and institutional issues associated with them, including claims from third parties who allege damages from flooding. The principal elements of cloud seeding includeselection of cloud masses, seeding materials, and methods to dispense the agents within the clouds. Several classes of seeding agents are available. Seeding agents are introduced into the clouds by either ground-based generators or aerial delivery systems.Precipitation from clouds is a result of two different processes or mechanisms. The first is coalescence,whereby tiny cloud droplets collide to form larger droplets that eventually fall as rain. The coalescence process works at temperatures above freezing. The secondmechanism requires ice particles and occurs at subfreezing temperatures. Many clouds contain supercooled water droplets, sometimes at temperatures far below freezing. Eventually the ice particles fall as snow (which will change to rain if the lower levels of the atmosphere are above freezing). Enhancing either of the two processes of precipitation formation can lead to more efficiency in producing rain or snow from a cloud. Some natural clouds appear to be deficient in ice forming nuclei; those clouds offer an opportunity to assist the rainmaking process. Cloud Seeding Agents. Certain materials haveT ECHNOLOGY I N W ATER M ANAGEMENT 5-22 The California Water Plan Update B ULLETIN 160-98



### been found effective in converting supercooled water droplets into ice crystals. Commonly used seeding agents for this purpose are silver iodide and dry ice.Some other chemicals also work, including some organic compounds. Hygroscopic materials such as salt, urea, and ammonium nitrate have been used in warmer clouds to assist the coalescence process. Dry ice was frequently used in early cloud seeding programs in the United States in the 1950s and early1960s. A switch to silver iodide occurred in the mid1960s, probably because of more convenient storageand dispensing capabilities (dry ice applications are limited to airborne delivery systems). Dry ice has received increased attention in recent years due to its low cost and high effectiveness. Silver iodide has been the preferred seeding agent in the majority of cloud seeding programs in the United States. Particles of silver iodide are usually produced through a combustion process followed by rapid quenching which forms trillions of effective freezingnuclei per gram of silver iodide consumed. Cloud seeding by silver iodide can be carried out using ground-based or aerial generators. Liquid propane is a freezing agent much like dry ice. Liquid propane has the advantage of working athigher temperatures, up to a degree or two below freezing, whereas silver iodide is not very effective when temperatures are warmer than -5 0 

### C. Dispensing is limited to ground-based systems because it is a flammable substance. Liquid propane sprayed into the atmosphere chills the air to temperatures well below 0 0 

### C. As temperatures approach -40 o 

### C, water vapor in the air rapidlycondenses into trillions of cloud droplets which immediately freeze and grow into tiny ice crystals. Propane is used operationally in clearing supercooled fog fromairports in Alaska and the northern portion of the continental U.S. Pseudomonas syringae , a bacterium thought to reduce frost damage in plants, has been shown to be an effective nucleating agent. Use of this bacterium as a seeding agent has been limited to producing snow in ski resorts, although there have been some experiments with aerial applications. Cloud Seeding Delivery Systems. Commonlyavailable aircraft can be modified to carry an assortment of cloud seeding devices. Silver iodide nuclei dispensers include pyrotechnic dispensers and models
that burn a solution of silver iodide and acetone. Inthe burning process, a typical silver iodide-acetone solution is forced through the nozzle into a combustion chamber where it is ignited, and the silver iodide crystals formed through combustion are expelled into theatmosphere. Pyrotechnics are similar to ordinary highway flares. Pyrotechnic flares impregnated with silver iodide can be mounted on aircraft, burned, and dropped into the clouds. Dry ice is frequently dispensedthrough openings through the floor of aircraft modified for cloud seeding. Types of aircraft used in operational cloud seeding programs range from a single engine aircraft to larger twin engine aircraft.The most common type of ground generator consists of a solution tank which holds the seeding agent. Other components include a means of pressurizing thesolution chamber, dispensing nozzles, and a combustion chamber. Frequently, such systems employ a propane tank with a pressure reduction regulator to pressurize the solution tank, as well as to provide
as a combustible material into which the silver iodideacetone solution is sprayed. Other systems utilize nitrogen to pressurize the solution tank. Pyrotechnicsare also used at surface sites. Ground generation systems have been developed which are operated manually or by remote control. Effectiveness. Although precise evaluations of the amount of water produced are difficult and expensive to determine, estimates range from 2 to 15 percent increase in annual precipitation, depending on the number and type of storms seeded. In 1992, both theAmerican Meteorological Society and the World Meteorological Organization issued policy statements cautiously supportive of the effectiveness of weather modification efforts under the proper circumstances.

Long-Term Weather Forecasting California’s experience with flood and drought cycles demonstrates that significant economic benefits would result from the development and application of successful long-term weather forecasting capabilities.With the ability to predict weather patterns in an accurate and timely manner, water resources managers could plan for and mitigate losses associated with floods and droughts. During the 1980s, research on ocean and atmospheric interactions in the tropical Pacific Ocean produced new and significant insights into the predict ability of the so-called El Niño Southern Oscillation cycle. New weather forecasting capabilitiesdeveloped through research on ENSO suggest potential applications in addressing water resources management issues.T ECHNOLOGY I N W ATER M ANAGEMENT 5-23 The California Water Plan Update B ULLETIN 160-98



### Climate researchers at Scripps Institution ofOceanography are engaged in several efforts to provide experimental climate forecasts up to twelve months
in advance. One of these efforts is focused on the use of climate forecasts to improve California’s use of its scarce water resources. Scripps is leading a team of University of California scientists to downscale global climate predictions to describe impacts on local water supplies. See Chapter 3 for a discussion on climate variability.

Environmental Water Use Technologies

Wetlands Management
Wetland plants have been found to remove selenium from water applied to them. University of California, Berkeley, researchers are experimenting in the Tulare Lake Drainage District with wetland plantsirrigated with high-selenium drain water in flowthrough cells. Careful management of such facilitiesto remove selenium while avoiding food chain concentrations may result in developing safe operatingcriteria for wetlands supplied with agricultural drainage water. This may provide another alternative for drainage water management. (Drainage water not used to support wetlands would still have to be disposed of by other means, such as evaporation ponds.)

Real-Time Water Quality Management
One of the actions identified in the 1995 SJRMPplan was establishing a real-time water quality monitoring network for the San Joaquin River, to support water management decisions. The monitoring network collects water quality and quantity data for input to a computer model that forecasts water flow and quality along the lower San Joaquin River. A goal of the real-time monitoring network is toenable water managers to meet San Joaquin River water quality objectives more often and more efficiently. For example, information provided by the network can support decisions related to reservoir releases at New
Melones. A recently completed demonstration project added instrumentation sites, developed analytical tools to collect and process the data, and disseminated weekly forecasts of daily San Joaquin River flow and salinity at Vernalis. In 1997, CALFED approved Category III funding to implement a two year program to expand the monitoring network. The program is scheduled to begin in fall 1998.

Fish Screen Technologies State of the Art. Fish screens on water supply diversions protect fish from potential entrainment losses. A properly designed fish screen, with appropriate sweeping velocities past the screen, allows diversionsto occur (even when juvenile fish may be present) without causing unacceptable fish losses. Fishery and water interests have been working together for several yearsto improve existing screens and add them to older diversions that lack screens.
NMFS and DFG have mandates for the installation and operation of fish screens. If a new diversion is installed or significant changes are made to an existing intake, a new fish screen is usually required. DFG has established a prioritized list of diversions that should be screened based on potential fish losses. Protecting the most significant diversions first will help achievefish protection goals with the available financial resources. Programs to financially assist diverters in the installation of such screens are available through theCVPIA’s AFRP, CALFED’s ecosystem restoration program, the Natural Resources Conservation Service, and provisions of Proposition 204.Current fish screen technology reflects criteria established by NMFS and DFG. Physical screens, combined with low approach velocities and proper cleaning systems, can effectively protect fish greater than about 1 inch long. Conventional screens will not protect smaller or larval-sized fish which may be present
at some sites for limited durations. Smaller pumped diversions (slant or vertical pumpinstallations on a river with flows less than 40 cfs) generally use bolt-on screens available from a variety of
manufacturers. These screens are similar to those usedto reduce debris in sprinkler irrigation systems. Depending on the site and the system, screens may be made of corrosion resistant woven wire, perforatedplate, or wedge-wire material (well screen). These materials can be formed into cylindrical shapes or flat plate panels and designed into the intake system.The number of sites with fish screens (or fish passage improvements) has increased with the availability of public funding assistance (Figure 5-1). For example,the Maxwell Irrigation District now operates a stateof-the-art positive barrier fish screen, one of the first
of its kind installed on the Sacramento River. Completed in 1994, the new pumping plant and screenT ECHNOLOGY I N W ATER M ANAGEMENT 5-24 The California Water Plan Update B ULLETIN 160-98

In February 1998, two large cylindrical fish screens were installed at one of the largest Delta diversions on
Sherman Island.



### facility diverts approximately 80 cfs at a completed cost of nearly $1.6 million. The screens are intended toprotect all fish, but primarily steelhead and winterrun chinook salmon. In 1994, Pelger Mutual WaterCompany completed construction of its new pumping station and positive barrier fish screen near Knights Landing on the Sacramento River. The facility includes pumps with a discharge capacity of 60 cfs and was completed for a total cost of $350,000.Larger diversion sites are screened with low approach positive velocity barrier screens. These intake screens may include significant civil works and are often off the main river channels where they must providefish handling and bypass systems. These facilities require more attention to hydraulic conditions than
smaller intake screens. Several recently constructed facilities have been designed to current regulatory criteria for screening, including screens at the M&T Chico Ranch diversion on the Sacramento River, the Parrott-Phelan diversion on Butte Creek, and the Tehama-Colusa Canal. As part of its environmental restoration activities, M&T Chico Ranch relocated its screened pump station from the mouth of Big Chico Creek to the Sacramento River. This $5 million project provides water supply to over 8,000 acres of permanent wetlands and over 1,500 acres of seasonal wetlands, in addition to protecting habitat for migrating spring-run chinook salmon. Several large facilities are nearing the final phases of design or construction. They include diversions on the Sacramento River at the Glenn-Colusa Irrigation District, Reclamation District 108 near Grimes,Reclamation District 1004 near Princeton, PrincetonCodora-Glenn Irrigation District and ProvidentIrrigation District consolidated diversion, Browns Valley Irrigation District diversion on the Yuba River, andothers. Construction of GCID’s Hamilton City Pumping Plant screen began in spring 1998. This $70 million project will minimize fish losses near the pumping plant and will maximize GCID’s capability to divert its full irrigation supply. Reclamation District 108 began construction in 1997 on a new $10 million A newly constructed fish passage and screening facility on
Butte Creek.T ECHNOLOGY I N W ATER M ANAGEMENT 5-25 The California Water Plan Update B ULLETIN 160-98

5 7 13

10

12

11 15

9

14 3

2 4 17 18 19 20

6 16

1 8

1

2

3

4

5

6

7

8

9

10 Sacramento River - M&T Chico Ranch, 1997

Butte Creek - Adams Dam, 1998

Butte Creek - Durham Mutual Dam, 1998

Butte Creek - Gorrill Dam, 1998

Butte Creek - Parrott - Phelan, 1996
Rock Slough - Contra Costa Canal, 1998

Sacramento River - Glenn-Colusa ID, 1998

Sacramento River - Maxwell ID, 1994
Sacramento River - Pelger MWC, 1994

Sacramento River - Princeton - Codora -

Glenn ID/Provident ID, 1998 11

12

13

14

15

16

17

18

19

20 Sacramento River - RD 108, 1998

Sacramento River - RD 1004, 1998

Sacramento River - Wilson Ranch, 1995
Suisun Marsh - Five Projects, 1996-1997
Yuba River - Browns Valley ID, 1998

Tehama - Colusa Canal, 1990

Butte Creek - Western Canal WD Dams, 1998

Butte Creek - Point Four Diversion Dam, 1993

Butte Creek - McGowan Dam, 1998

Butte Creek - McPherrin Dam, 1998 F IGURE 5-1 Recent Structural Fishery ImprovementsT ECHNOLOGY I N W ATER M ANAGEMENT 5-26 The California Water Plan Update B ULLETIN 160-98

This circular flume, called the fish treadmill, simulates the hydraulic conditions that fish may encounter in the Delta. DWR’s three year treadmill study began in 1997. 

### fish screen. The project, located at the district’s Wilkins Slough diversion, will protect migrating winter-run chinook salmon and other fish. The district anticipates completing the project by the 1999 irrigation season. Reclamation District 1004 began construction of its $8 million fish screen in 1998. The project includesrelocation of the Princeton Pumping Plant and conveyance facilities, in addition to a positive barrier fish screen. In 1998, the Princeton-Codora-Glenn and Provident irrigation districts are expected to complete construction of an $11 million fish screen and pump consolidation project. The 600 cfs project eliminates
three unscreened diversions.
Current Research. There is significant researchand experience in fish screen technology. The technology has responded to a number of factors including ESA requirements in the Northwest and in Californiafor the protection of salmonids, FERC relicensing requirements, and the heightened awareness of fish losses
at diversions.Research can be broken down into two categories: positive barrier technologies and behavioral barrier technologies. Although physical screens are considered state of the art, and are acceptable to the resource agencies, behavioral barriers have been demonstrated to deter fish from being diverted at some sites and may offer enhanced fish protection at even physically
screened sites. Several significant applied research projects are under way on positive barrier technologies. A research pumping plant has been constructed at the USBR’s
Red Bluff Diversion Dam to divert Sacramento River water into the Tehama-Colusa Canal. This facility (see photo, Chapter 2) was developed to provide water to
the Tehama-Colusa Canal when the diversion dam gates are raised for fish passage. The research pumping plant is testing centrifugal and Archimedes screw pumptechnologies to evaluate their impacts on fish. The research plant and the biological evaluations of itseffectiveness now being carried out are providing valuable data on the potential application of these technologies to other sites. Since the early 1950s, fish screen design criteria have been developed for juvenile salmon and a few other anadromous species. Little is known about the screening requirements for resident Bay-Delta species (such as smelt) which require protection. Through acooperative interagency program effort, a large circular screened testing flume has been constructed at University of California at Davis to investigate fishperformance and behaviors under various hydraulic conditions. This research will improve understanding of the needs of fish and help design
more effective screens.Screen cleaning and proper operation and maintenance are essential for the reliability of diversion andfish protection. In the last 10 years, cleaning technologies have advanced in response to possible zebra musselinvasions and clogging from aquatic weeds. Combinations of hydraulic and air backwash systems, improved horizontal and vertical brush cleaners, andautomated controls have proven effective. Screen materials and coatings have also been developed to prevent biofouling. Some investigations under way includeUSBR’s Tracy Pumping Plant Fish Facility Improvement Program, Contra Costa Water District’s new Los Vaqueros and proposed Rock Slough fish screens, and an investigation of air cleaning systems by USBR.Higher velocity fish screens, which reduce exposure to the screen surface, are being studied. These systems are potentially less expensive because of thereduced screen area required. Modular systems are being developed for wider application. Advances inT ECHNOLOGY I N W ATER M ANAGEMENT 5-27 The California Water Plan Update B ULLETIN 160-98



### automation and control systems are being used to regulate screens’ hydraulics and operations and provide better fish protection and diversion reliability. Technological advances have renewed interest in acoustic and electrical fish guidance systems. In the past, these systems have had limited success affecting fish behavior. Some guidance and protection had been observed, but the systems could not achieve the levelof protection desired by State and federal resource agencies. Fish responses to behavioral technologies arevariable since they may respond to other environmental stimuli, including hydraulic conditions,temperature, predator avoidance, and lighting conditions. Behavioral barriers are attractive in some casesbecause physical barriers may not be viable or costeffective.

Temperature Control TechnologyTemperature control technology is used to manage temperature of reservoir releases to improve conditions for downstream fisheries. During summer months, reservoir temperature gradients result in warmer water near the surface of a reservoir, with coolerwater remaining near the bottom. Two types of temperature control devices are currently being used in
Northern California reservoirs: variable-level outlets Behavioral Barrier Demonstration Projects

Several behavioral barrier demonstration projects have been evaluated in the Central Valley. Georgiana Slough Acoustic Barrier

Juvenile salmon survival has been shown to improve significantly if salmon are allowed to remain in the Sacramento River rather than being drawn into the central Delta via Georgiana Slough. Physical barriers and screens have been considered at this site, but are not feasible because of hydraulic conditions, water quality, recreational uses, and adult fish migration issues. A behavioral system is being studied which would improve fish survival by guiding them away from the hydraulic influence of Georgiana Slough. Twenty-one underwater acoustic speakers were installed at the Sacramento River’s junction with the Slough below the town of Walnut Grove. Studies in 1993, 1994, and 1996 showed improved guidance during low flows, but mixed results at higher
flow conditions. R esults have been encouraging enough to continue investigations at this site under low flow conditions. Adverse effects of acoustic system operation have not been
observed.
Reclamation District 108 Acoustic and Electrical Barrier

At this major Sacramento River diversion (700 cfs diversion capacity) near Grimes, acoustic and electrical barriers were tested to see if these technologies could reduce fish losses. Tests were conducted at the site from 1993 until 1996 with mixed results. The acoustic system was suspended from the surface and operated on an on/off cycle to test its effectiveness. The electrical array was mounted to an underwater louver array and was similarly evaluated. Since neither system achieved the required reduction in fish entrainment, RD 108 is constructing a positive barrier fish screen.
Reclamation District 1004 Acoustic Barrier

A similar acoustic barrier was installed at RD 1004’s
diversion on the Sacramento River near the town of Princeton. From 1994 to 1995, the system was evaluated and found to have marginal benefits. RD 1004 is installing a 360 cfs positive
barrier fish screen at its diversion site.
Behavioral Research at Other Sites The use of low frequency “infrasound” systems and the use of lighting systems (strobe lights) is under investigation at several sites outside of California. Many of these systems are being tested and used with other screening technologies to attempt to improve their effectiveness in difficult hydraulic

environments.



### that permit temperature selective releases, such as USBR’s Shasta Dam TCD; and temperature control curtains, such as those at Whiskeytown and Lewiston

Reservoirs. Temperature Control Devices. Some dams, such as the Department’s Oroville Dam, were constructed with temperature-selective reservoir release capability.
Retrofits to reservoir outlets can be constructed for those that were not, such as USBR’s Shasta Dam. USBR completed the Shasta Dam TCD in May 1997,and is now fixing leakage problems that affect operation of the device. The structural steel shutter device is 250 feet wide by 300 feet high and encloses all five penstock intakes on the dam. The shutters allow forselective withdrawal of water, depending on downstream temperature needs. Prior to installation of the structure, USBR had to bypass Shasta powerplant to provide water of adequate temperature. Installation of the TCD will provide USBR with the flexibility to provide optimal water temperature downstream for the salmon fishery, and allow for hydropower generation. Temperature Control Curtains. Curtains can control water withdrawal at intake or outlet structures to provide desired temperatures for salmonids and other aquatic species, allowing water to be conserved for otheruses. Four temperature control curtains have been inT ECHNOLOGY I N W ATER M ANAGEMENT 5-28 The California Water Plan Update B ULLETIN 160-98



### stalled by USBR, two in Lewiston Reservoir (in 1992), and two in Whiskeytown Reservoir (in 1993). Thesecurtains are constructed of Hypalon, a rubberized nylon fabric. They are supported in the water column by steel tank floats and anchored to stay in place. At Lewiston Reservoir, an 830-foot-long, 35-foot deep curtain is suspended from flotation tanks and secured by a cable and anchor system. This curtain was designed to block warm surface water from the Clear Creek Tunnel intake. As a result, cold water
from the bottom of the reservoir is diverted to Whiskeytown R eservoir. A second curtain was installed around the Lewiston Fish Hatchery intake structure to allow warmer or colder water, depending on the season, to be taken into the hatchery. The curtain,300 feet long by 45 feet deep, was designed to either skim warmer water or underdraw cooler water, depending on whether the curtain was in a sunken or floating position. Ideally, cold water diverted from Lewiston should be routed through Whiskeytown’s hypolimnion (deep,cold water layer) into the Spring Creek Conduit intake. To accomplish this, two curtains were installed: a tailrace curtain downstream at Carr Powerplant, andan intake curtain surrounding the Spring Creek Conduit intake. The tailrace curtain (600 feet long and 40 feet deep) was installed to force cold water from Carr Powerplant into Whiskeytown’s hypolimnion with a limited amount of mixing with the epilimnion(warm surface water). This curtain restrains warm surface water from moving upstream toward Carr Powerplant. With the tailrace curtain in place, mixing is reduced where the density current plunges into thehypolimnion upstream of the tailrace curtain. The second curtain (a 2,400-foot long, 100-foot deep, surface-suspended curtain) surrounds the Spring CreekConduit intake. This curtain, like the Lewiston curtain, was designed to retain warm surface water while allowing only cold water withdrawal. The temperature curtains at Lewiston and Whiskeytown Reservoirs reduce the temperature of Trinity River diversions to the Sacramento River by as much as 5 0 

### F. According to USBR, this decrease is significant, making the temperature curtains a successful tool for conserving reservoir releases.The smaller temperature control curtains generally cost about $1,000 per foot. The large curtain at Whiskeytown Reservoir cost about $1.8 million. Theexpected duration of use is about 10 years before replacement may be required. To date, none of the four curtains in place at these two reservoirs has needed major repairs. A number of studies are ongoing to better refinethe curtains’ use for temperature control, and to ensure that no adverse impacts result to biological resources in the reservoirs where they are installed.

### i The California Water Plan Update B ULLETIN 160-98

D E P A R T M E N T O

F W A

T E R R E S O U R C E S

S T A T E O

F C A

L I F O R N I A 

# C ALIFORNIA


# W ATER 

# P LAN 

# U PDATE


# B ULLETIN 

# 160-98

Volume 2

November 1998

Pete Wilson

Governor

Douglas P. Wheeler Secretary for Resources The Resources Agency

David N. Kennedy

Director Department of Water Resources

### ii The California Water Plan Update B ULLETIN 160-98

Department of Water Resources, Sacramento, 1998

Copies of Bulletin 160-98 may be purchased for $25 from: California Department of Water Resources
P. O. Box 942836 Sacramento, CA 94236-0001

Make checks payable to: Department of Water Resources
California residents add current sales tax C

### iii The California Water Plan Update B ULLETIN 160-98



### Chapter 6. Evaluating Options From a Statewide Perspective Statewide Water Budget .............................................................................................................................. 6-2 The Bulletin 160-98 Planning Process ........................................................................................................ 6-2 Major Steps in Planning Process ........................................................................................................... 6-4 Shortage Management .......................................................................................................................... 6-6 Using Applied Water Budgets to Calculate New Water Needs .............................................................. 6-6 Demand Reduction Options ....................................................................................................................... 6-8 Urban Water Conservation Options ..................................................................................................... 6-9

Outdoor Water Use ....................................................................................................................... 6-9

Residential Indoor Water Use ................................................................................................... ... 6-10

Interior CII Water Use ................................................................................................................. 6-10 Distribution System Losses .......................................................................................................... 6-11 Agricultural Water Conservation Options ........................................................................................ .. 6-11 Irrigation Management (Options 1, 2, and 3) .............................................................................. 6-12 Water Delivery Flexibility (Option 4) .......................................................................................... 6-13 Canal Lining and Piping (Option 5) ............................................................................................ 6 -13 Tailwater and Spill Recovery Systems (Option 6) ......................................................................... 6-13 Environmental Water Conservation Options ...................................................................................... 6 -13 Water Supply Augmentation Options ....................................................................................................... 6-14 Conveyance Facilities ......................................................................................................................... 6-14 SWP Interim South Delta Program ............................................................................................. 6-14 CALFED Delta Conveyance ........................................................................................................ 6-14 Mid-Valley Canal ......................................................................................................................... 6-16 Surface Storage Facilities ..................................................................................................................... 6-16 Area of Origin Protections ........................................................................................................... 6-16 CALFED Surface Storage ......................................................................................................... ... 6-16 Multipurpose Storage Facilities ................................................................................................ .... 6-20 Groundwater and Conjunctive Use ................................................................................................ .... 6-22 Potential for Conjunctive Use in the Central Valley ..................................................................... 6-22 Recent Groundwater Studies with Statewide Scope ...................................................................... 6-23 Water Marketing ............................................................................................................................... 6-25 Sources of Water for Marketing ................................................................................................. .. 6-26 Prospects for Water Marketing .................................................................................................. ... 6-27 Drought Year Marketing .............................................................................................................. 6-29 Every Year Marketing ................................................................................................................... 6-31 Water Recycling and Desalting ........................................................................................................... 6-32 Water Recycling ........................................................................................................................... 6-32 

# Contents

. . .

### iv The California Water Plan Update B ULLETIN 160-98



### Desalting ..................................................................................................................................... 6-33

Weather Modification ........................................................................................................................ 6-35 Other Supply Augmentation Options.............................................................................................. ... 6-36 Importing Water from Out of State ............................................................................................. 6 -36
Gray Water .................................................................................................................................. 6-36 Watershed Management on National Forest Lands ...................................................................... 6-36 Long-Range Weather Forecasting ................................................................................................. 6-37 Summary of Statewide Supply Augmentation Options ....................................................................... 6-37

CALFED ..................................................................................................................................... 6-37 Other Statewide Options ............................................................................................................. 6-38 Allocating Options Yield Among Hydrologic Regions ................................................................. 6-38 Uncertainties in the Bulletin Planning Process ............................................................................. 6-38 Options for Future Environmental Habitat Enhancement ........................................................................ 6-41 Central Valley Project Improvement Act ......................................................................................... .... 6-41 Category III Program ......................................................................................................................... 6-45 CALFED Bay-Delta Ecosystem Restoration Program ......................................................................... 6-46 Other Environmental Enhancement Options ..................................................................................... 6-47 SWP’s Sherman and Twitchell Islands Wildlife Management Plans .............................................. 6-47 Fish Protection Agreements.......................................................................................................... 6-47 Upper Sacramento River Fisheries and Riparian Habitat Restoration Program ............................. 6-47 Financing Local Water Management Options ....................................................................................... .... 6-47

Sources of Revenues ........................................................................................................................... 6-48 Financing Methods............................................................................................................................. 6-48 Self-Financing .............................................................................................................................. 6-49 Short-Term Debt Financing ...................................................................................................... ... 6-49 Conventional Long-Term Debt Financing ................................................................................... 6-49 Innovative Long-Term Debt Financing ........................................................................................ 6-49

Credit Substitution and Enhancement ......................................................................................... 6-50 State and Federal Financial Assistance Programs........................................................................... 6-51 Relationship Between Financing and Water Agency Ownership and Size ........................................... 6-51 Public Water Agencies .................................................................................................................. 6-51

Investor-Owned Water Utilities ................................................................................................. .. 6-51 Mutual Water Companies ......................................................................................................... ... 6-52

Appendix 6A. Regional Water Budgets with Existing Facilities and Programs............................................6A-1

Appendix 6B. Applied Water Shortages by Hydrologic Region with Existing Facilities and Programs ....... 6B-1

Appendix 6C. Estimating a Water Management Option’s Unit Cost ........................................................ 6C-1

Appendix 6D. Calculation of Minimum New Water Needs ..................................................................... 6D-1

Appendix 6E. Net Water Budgets ............................................................................................................. 6E-1

### v The California Water Plan Update B ULLETIN 160-98



### Appendix 6F. Land Retirement Analysis in Drainage-Impaired Areas ........................................................ 6F-1

Appendix 6G. Review and Evaluation of Statewide-Level Storage Facilities That Could Be Included in CALFED Alternatives .............................................................................................................................. 6G-1

Chapter 7. Options for Meeting Future Water Needs in Coastal Regions of California North Coast Hydrologic Region ................................................................................................................. 7-3 Description of the Area ........................................................................................................................ 7-3 Water Demands and Supplies ............................................................................................................... 7-3 Local Water Resources Management Issues ........................................................................................ ... 7-5 Klamath River Fishery Issues.......................................................................................................... 7-5 Trinity River Fish and Wildlife Management Program ................................................................... 7-5
Water Supplies of Small Coastal Communities .............................................................................. 7-6

Russian River Environmental Restoration Actions ......................................................................... 7-7 City of Santa Rosa Long-Term Wastewater Project ........................................................................ 7-8 SCWA Water Supply and Transmission Project .............................................................................. 7-8 Potter Valley Project ....................................................................................................................... 7-8 Water Management Options for the North Coast Region .................................................................... 7-8

Water Conservation ....................................................................................................................... 7-8 Modifying Existing Reservoirs or Operations ............................................................................... 7-10
New Reservoirs and Conveyance Facilities ................................................................................... 7-10 Groundwater Development or Conjunctive Use .......................................................................... 7-11 Water Recycling ........................................................................................................................... 7-11 Desalting ..................................................................................................................................... 7-11
Other Local Options.................................................................................................................... 7-11 Options Likely to be Implemented in North Coast Region ................................................................ 7-11 San Francisco Bay Hydrologic Region ....................................................................................................... 7-15 Description of the Area ...................................................................................................................... 7-15 Water Demands and Supplies ............................................................................................................. 7-15 North Bay .................................................................................................................................... 7-15
South Bay .................................................................................................................................... 7-17 Local Water Resources Management Issues ........................................................................................ . 7-20 Bay-Delta Estuary ........................................................................................................................ 7-20

Suisun Marsh ............................................................................................................................... 7-20 Local Water Agency Issues ........................................................................................................... 7-20 Bay Area Regional Water Recycling Program ............................................................................... 7-24 Water Management Options for the San Francisco Bay Region .......................................................... 7-24

Conservation ............................................................................................................................... 7-24 Modify Existing Reservoirs/Operations ........................................................................................ 7- 24
New Reservoirs and Conveyance Facilities ................................................................................... 7-27

### vi The California Water Plan Update B ULLETIN 160-98



### Groundwater Development or Conjunctive Use .......................................................................... 7-28 Water Marketing .......................................................................................................................... 7-28 Water Recycling ........................................................................................................................... 7-28 Desalting ..................................................................................................................................... 7-29
Other Local Options.................................................................................................................... 7-29
Statewide Options ....................................................................................................................... 7-29 Options Likely to be Implemented in San Francisco Bay Region ........................................................ 7-29 Central Coast Hydrologic Region ............................................................................................................. 7-33 Description of the Area ...................................................................................................................... 7-33 Water Demands and Supplies ............................................................................................................. 7-34

Northern PSA .............................................................................................................................. 7-34

Southern PSA .............................................................................................................................. 7-34 Local Water Resources Management Issues ........................................................................................ . 7-35

Seawater Intrusion ....................................................................................................................... 7-35 Local Water Agency Issues ........................................................................................................... 7-36 Seawater Desalting ....................................................................................................................... 7-37 Water Management Options for the Central Coast Region ................................................................ 7-37

Water Conservation ..................................................................................................................... 7-40 Modify Existing Reservoirs or Operations .................................................................................... 7-40
New Reservoirs and Conveyance Facilities ................................................................................... 7-40 Groundwater Development and Conjunctive Use ........................................................................ 7-41 Water Marketing .......................................................................................................................... 7-41 Water Recycling ........................................................................................................................... 7-42 Desalting ..................................................................................................................................... 7-42
Other Local Options.................................................................................................................... 7-42
Statewide Options ....................................................................................................................... 7-42 Options Likely to be Implemented in Central Coast Region .............................................................. 7-42 South Coast Hydrologic Region ................................................................................................................ 7-47 Description of the Area ...................................................................................................................... 7-47 Water Demands and Supplies ............................................................................................................. 7-47 Los Angeles Aqueduct .................................................................................................................. 7-48
Colorado River Aqueduct ........................................................................................................ .... 7-48
State Water Project....................................................................................................................... 7-49 Local Surface Water Supplies ................................................................................................... .... 7-50 Groundwater Supplies ................................................................................................................. 7-52 Local Water Resources Management Issues ........................................................................................ . 7-54 Water Supply Reliability .............................................................................................................. 7-54 Management of California’s Colorado River Water ...................................................................... 7-56

Mono Basin ................................................................................................................................. 7-57

### vii The California Water Plan Update B ULLETIN 160-98



### Restoration of Coastal Wetlands and Estuaries ............................................................................. 7-57

Flood Control .............................................................................................................................. 7-58 Salinity Management Actions .................................................................................................... .. 7-59

Groundwater Issues...................................................................................................................... 7-60 Southern California Comprehensive Water Reclamation and Reuse Study ................................... 7-61 Water Marketing .......................................................................................................................... 7-61 New Conveyance Facilities from Colorado River Region to South Coast Region ......................... 7-62 Mexican Border Environmental Quality Issues ............................................................................ 7-62 Water Management Options for South Coast Region ......................................................................... 7-62

Water Conservation ..................................................................................................................... 7-63 Modify Existing Reservoirs or Operations .................................................................................... 7-63

New Reservoirs ............................................................................................................................ 7-63 Groundwater Development and Conjunctive Use ........................................................................ 7-67 Water Marketing .......................................................................................................................... 7-67 Implementing the CRB’s Draft 4.4 Plan ...................................................................................... 7-68 Water Recycling ........................................................................................................................... 7-68 Desalting ..................................................................................................................................... 7-70 Other Local Options.................................................................................................................... 7-71 Statewide Options ....................................................................................................................... 7-71 Options Likely to be Implemented in South Coast Region ................................................................. 7-71

Appendix 7A. Options Evaluations for Coastal Regions ........................................................................... .7A-1

Chapter 8. Options for Meeting Future Water Needs in Interior Regions of California Sacramento River Hydrologic Region ......................................................................................................... 8-3 Description of the Area ........................................................................................................................ 8-3 Water Demands and Supplies ............................................................................................................... 8-3 CVP Water Supply ........................................................................................................................ 8-4 Supply from Other Federal Water Projects ..................................................................................... 8-5 SWP Water Supply ........................................................................................................................ 8-5 Local Surface Water Supply............................................................................................................ 8-5 Groundwater Supply...................................................................................................................... 8-6 Local Water Resources Management Issues ........................................................................................ ... 8-6 Sierra Nevada Foothills Water Supply ........................................................................................... . 8-6 Foothill Area Water Supply from American River Basin ................................................................. 8-7

Sacramento Area Water Forum .................................................................................................... .. 8-8 Colusa Basin Drainage District ...................................................................................................... 8-9 Groundwater Management Actions ............................................................................................... 8-9

American River Flood Protection ................................................................................................ . 8-10

Yuba River Flood Protection .................................................................................................... .... 8-11

### viii The California Water Plan Update B ULLETIN 160-98



### Sacramento River Mainstem Flood Protection and Water Supply................................................. 8-12 Putah Creek Adjudication ............................................................................................................ 8-12 Fish Passage at Red Bluff Diversion Dam ..................................................................................... 8-12 Glenn-Colusa Irrigation District Fish Screen ............................................................................... 8-13 Fish and Wildlife Restoration Activities in the Sacramento Valley ................................................ 8-13 Water Needs for Rice Field Flooding............................................................................................ 8-15 Water Management Options for the Sacramento River Region ........................................................... 8-15

Water Conservation ..................................................................................................................... 8-15 Modify Existing Reservoirs/Operations ........................................................................................ 8- 15

New Reservoirs ............................................................................................................................ 8-17 New Conveyance Facilities ........................................................................................................... 8-19 Groundwater Development or Conjunctive Use .......................................................................... 8-19 Water Marketing .......................................................................................................................... 8-19 Water Recycling ........................................................................................................................... 8-19
Other Local Options.................................................................................................................... 8-19
Statewide Options ....................................................................................................................... 8-20 Options Likely to be Implemented in the Sacramento River Region................................................... 8-20 San Joaquin River Hydrologic Region ....................................................................................................... 8-23 Description of the Area ...................................................................................................................... 8-23 Water Demands and Supplies ............................................................................................................. 8-24

Surface Water............................................................................................................................... 8-24

Groundwater ............................................................................................................................... 8-26 Local Water Resources Management Issues ........................................................................................ . 8-27 Cosumnes River Flood Management ........................................................................................... 8-27 Integrity of Delta Levees .............................................................................................................. 8-27 Interim South Delta Program and Temporary Barriers Project ..................................................... 8-28
San Joaquin County Groundwater Overdraft ............................................................................... 8-29

Penn Mine Remediation ......................................................................................................... .... 8-29
Conservation Storage in Farmington Reservoir ............................................................................ 8-29 New Melones Reservoir Water Supply and Operations ................................................................ 8-30
Urban Growth Pressures from San Francisco Bay Area ................................................................. 8-30
East County Water Supply Study ................................................................................................. 8-31

Los Banos Grandes Reservoir Studies ........................................................................................... 8 -31 Merced Area Conjunctive Use Study............................................................................................ 8- 32 Agricultural Drainage .................................................................................................................. 8-32 Enlargement of Friant Dam ...................................................................................................... ... 8-33 Instream Flow Requirements Below Friant Dam .......................................................................... 8-33
Environmental Restoration Activities in the San Joaquin River Basin ........................................... 8-33
San Joaquin River Parkway Development .................................................................................... 8-34

### ix The California Water Plan Update B ULLETIN 160-98



### January 1997 San Joaquin River Region Flood Event ................................................................... 8-34 Water Management Options for the San Joaquin River Region .......................................................... 8-35

Water Conservation ..................................................................................................................... 8-35 Modify Existing Reservoirs .......................................................................................................... 8-35

New Reservoirs ............................................................................................................................ 8-35 New Conveyance Facilities ........................................................................................................... 8-37 Groundwater Development or Conjunctive Use .......................................................................... 8-38 Water Recycling ........................................................................................................................... 8-38 Desalting ..................................................................................................................................... 8-38 Statewide Options ....................................................................................................................... 8-38 Options Likely to be Implemented in the San Joaquin River Region .................................................. 8-38 Tulare Lake Hydrologic Region ................................................................................................................. 8-43 Description of the Area ...................................................................................................................... 8-43 Water Demands and Supplies ............................................................................................................. 8-44 Local Water Resources Management Issues ........................................................................................ . 8-45

Groundwater Overdraft ............................................................................................................... 8-45 Groundwater Banking Programs .................................................................................................. 8 -46 Agricultural Drainage .................................................................................................................. 8-46 Arroyo Pasajero and Other Westside Cross-Drainages .................................................................. 8-47 Kings River Fishery Restoration Actions ...................................................................................... 8- 47 Water Management Options for the Tulare Lake Region .................................................................... 8-47

Water Conservation ..................................................................................................................... 8-47 Modifying Existing Reservoirs and New Reservoirs ...................................................................... 8-49 New Conveyance Facilities ........................................................................................................... 8-50 Groundwater Development or Conjunctive Use .......................................................................... 8-50 Water Marketing .......................................................................................................................... 8-51 Water Recycling and Desalting .................................................................................................. .. 8-52 Statewide Options ....................................................................................................................... 8-52 Options Likely to be Implemented in the Tulare Lake Region ............................................................ 8-52

Appendix 8A. Options Evaluations for Interior Regions.......................................................................... ..8A-1

Chapter 9. Options for Meeting Future Water Needs in Eastern Sierra and Colorado River Regions of California North Lahontan Hydrologic Region ........................................................................................................... 9-3 Description of the Area ........................................................................................................................ 9-3 Water Demands and Supplies ............................................................................................................... 9-3 Local Water Resources Management Issues ........................................................................................ ... 9-7 Truckee River Operating Agreement .............................................................................................. 9-7

Walker River .................................................................................................................................. 9-8

Lake Tahoe .................................................................................................................................... 9-8