What’s an Acre Foot of Water?

• An acre-foot of water is about 326,000 gallons, or enough water to supply two typical families for a year.
  
• One acre-foot of water is enough to meet the needs of two typical families for a year.
  
• It takes 3.3 acre-feet of water to grow enough food for an average family for a year.

Household Water Use

• Landscaping accounts for about half the water Californians use at home. Showers account for another 18%, while toilets use about 20%.
• Central Valley residents use up to 300 gallons per person per day, while some Central Coast residents use as little as 50 gallons per day.
• How much water does it take to…
• Brush your teeth? - 2 to 5 gallons
• Wash the car? - 50 gallons
• Use the dishwasher? - 8 to 15 gallons
• Flush the toilet? - 1.5 to 4 gallons (each flush)
• Take a shower or bath? - 17 to 24 gallons
• Run the washing machine? - 35 to 50 gallons (each load)
• How you Can Use Water More Wisely?
• High efficiency clothes washers can make a big difference. Whereas old-style washing machines use about 45 gallons of water per load, new high efficiency models use only 15 gallons per load.
• We all love beautiful gardens and landscapes. But traditional lawns and gardens can require lots of water to maintain. For example, the typical lawn requires about 57 inches of water a year. While some of that comes from rain, the rest has to be provided by irrigation.
• A small lawn of 1,000 square-feet uses about 35,000 gallons of water per year. If the lawn is over-irrigated, as is common in many areas, it can use up to 75,000 gallons a year.
• Local water agencies can provide expert advice and tips on how to have a lovely yard and garden that uses much less water.
• “SMART” irrigation controllers are a good example of how technology is helping to reduce water use. These controllers monitor weather conditions and limit watering to when it’s really needed.
• Many local water agencies offer free water-wise visits that can provide water efficiency advice tailor-made for individual businesses.

Using Water Wisely

• As our population continues to grow, water use efficiency will be more critical than ever.
• Using water more efficiently reduces water and wastewater bills, and also lowers energy bills. It can also reduce demand on sensitive rivers and estuaries such as the Sacramento-San Joaquin River Delta, and help communities avoid the tremendous expense of developing new water supplies.
• California water agencies are leaders in water use efficiency. Over the past decade, local agencies statewide have invested roughly $400 million in programs to reduce water use.
• Today, water efficiency efforts in California rival those found anywhere in the world. Thanks to more efficient plumbing fixtures and active conservation programs, California is saving more than 700,000 acre-feet of water per year, enough to meet the household needs of over 2 million people for a year.
• Thanks to water use efficiency efforts, urban Southern California today uses about the same water it used in the 1980s – even though it’s population has grown significantly.
• Similarly, major water agencies in the San Francisco Bay Area report that total water demand today is about the same as it was in the 1980s, due to water-saving programs and incentives.
• From toilet rebates to water audits to “SMART” landscape irrigation technology, California water agencies are helping their customers use less water and less energy, without comprising their lifestyle.

Where Does Our Water Supply Come From?

• Precipitation varies widely from year to year. In average years, close to 200 million acre-feet (MAF) of water falls in the form of rain or snow in California.
• Over half of that water soaks into the ground, evaporates or is used by native vegetation. That leaves somewhere around 82 million acre-feet of usable surface water in average years. Of that water:
• 48% goes to environmental uses such as instream flows, wild and scenic river flows, required Delta outflow and managed wetlands.
• 41% is used by agriculture
• 9% is used by cities and industry.
• Most of the rain and snowfall occurs between October and April, while demand is highest during the hot and dry summer months.
• About 75% of California’s available water occurs north of Sacramento, while about 80% of the demand occurs in the southern two-thirds of the state.
• Groundwater provides about 40% of the state’s water supply. In dry years, that percentage can go as high as 60%.
• California is prone to both droughts and floods. The most recent prolonged dry spell was a six-year drought from 1987 to 1992. The most severe drought on record occurred in two consecutive years, 1976 and 1977, in which California received very little precipitation and surface water reservoirs were extremely low.

California’s Water Delivery (Federal, State and Local)

• California's communities, farms, businesses, and environment rely on water from a variety of sources. Surface water projects, which capture and deliver rain and snow runoff, provide a major portion of the state's total water supply. The projects include more than 1,000 federal, state and local reservoirs and conveyance systems.
• Two of the most important projects are the federal Central Valley Project (CVP) and the State Water Project (SWP). The CVP and SWP bring water from Northern California through the Sacramento-San Joaquin River Delta for delivery to users in the San Joaquin Valley, parts of the San Francisco Bay Area and Southern California.
• Local water agencies perform a number of functions to deliver water to California’s cities, farms and businesses. Local agencies fund, build and maintain water supplies.
• The 200 biggest reservoirs have a combined capacity of more than 41 million acre-feet.
• Reservoirs are operated for a number of purposes:

• Flood control
• Water supply
• Hydroelectricity generation
• Water quality improvement
• System flexibility
• Reliability against droughts / catastrophic events

• Key state and federal reservoirs were built 40 to 60 years ago.
• Some locally owned reservoirs were built 80 to 100 years ago.

The Central Valley Project (CVP)

• The CVP was formulated in the 1930’s as a way to prevent water shortages in the Central Valley, however, during the Depression the State was unable to finance the project in its entirety. Most of the water projects envisioned by the state were financed thru the federal government starting in 1935.
• There are over 200 CVP contractors who receive water from the project and in return, pay down the general obligation bonds and revenue bonds that were originally authorized.
• The CVP stretches 400 miles consisting of 20 dams and reservoirs, 11 power plants and 500 miles of canals. The CVP 200 contractors manage 9 MAF of water and generate 5.6 billion kilowatt hours of electricity to meet the needs of 2 million Californians.
• New Melones Reservoir is the last CVP storage facility completed in 1979.
• Central Valley Project Major Storage facilities (federal) -- 7 MAF
• Shasta Dam 4.55 MAF
• Trinity Dam 2.1 MAF
• Folsom Dam 1 MAF
• New Melones Dam 2.4 MAF
• Friant Dam and Millerton Reservoir 520,528 AF
• San Luis Dam and Reservoir 2.04 MAF

The State Water Project (SWP)

• The State Water Project is the nation’s largest state-built water and power conveyance system. It includes facilities—pumping and power plants; reservoirs, lakes, and storage tanks; and canals, tunnels, and pipelines—that capture, store, and convey water to 29 water agencies, which deliver 2.3 MAF of water.
• The SWP is comprised of 21 lakes and reservoirs with 5.8 MAF of total reservoir storage.

• State Water Project Reservoirs (state) -- 2.3 MAF
• Lake Oroville, ForeBay and AfterBay
• Lake Del Valle
• San Luis Reservoir
• Sisk Dam
• O’Neill Forebay
• Bethany Reservoir
• Lake Davis
• Frenchman Lake
• Antelope Lake
• Silverwood Lake
• Lake Perris
• Pyramid Lake
• Castaic Lake
• Quail Lake
• Devil Canyon Afterbay
• State Water Project Pumping and Powerplants –generates 6.5 billion kilowatt hours of electricity
• State Water Project Contracting Agencies (State Water Project Contractors)
• There are 29 State Water Project Contractors (SWP). SWP contractors are public water agencies who receive annual allocations, specified annual amounts of water, as agreed to in their contracts signed in the 1960’s and set to expire in 2035. In return, the contractors repay principal and interest in both general obligation bonds that initially funded the Project’s construction and the revenue bonds that paid for additional facilities. The contractors also pay all costs including labor and power to maintain and operate the Project’s facilities.
• State Water Project Contracting Agencies (State Water Project Contractors)
• City of Yuba
• County of Butte
• Plumas County Flood Control and Water Conservation District
• Napa County Flood Control and Water Conservation District
• Solano County Water Agency
• Alameda County Flood Control & Water Conservation District, Zone 7
• Alameda County Water District
• Santa Clara Valley Water District
• County of Kings
• Dudley Ridge Water District
• Empire West Side Irrigation District
• Kern County Water Agency
• Oak Flat Water District
• Tulare Lake Basin Water Storage District
• San Luis Obispo County Flood Control and Water Conservation District
• Santa Barbara County Flood Control and Water Conservation District
• Antelope Valley-East Kern Water Agency
• Castaic Lake Water Agency
• Coachella Valley Water District
• Crestline-Lake Arrowhead Water Agency
• Desert Water Agency
• Littlerock Creek Irrigation District
• Mojave Water Agency
• Palmdale Water District
• San Bernardino Valley Municipal Water District
• San Gorgonio Pass Water Agency
• The Metropolitan Water District of Southern California
• Ventura County Flood Control District

Local Water Agencies

• Local water agencies perform a number of functions to deliver water to California’s cities, farms and businesses.
• Local water agency projects include:
• All-American Canal (local) -- 3 MAF
• Colorado River Aqueduct (local) -- 1.2 MAF
• Los Angeles Aqueduct (local) -- 200,000 AF
• Mokelumne Aqueduct (local) -- 364,000 AF
• San Francisco Hetch Hetchy Project (local) -- 330,000 AF

• Many agencies purchase water from the major state and federal water projects. They then treat the water as needed, and deliver it to their customers.
• Some agencies operate their own local water supply systems, including reservoirs and canals that store and move water as needed.
• Some agencies rely on groundwater exclusively, and operate local wells and distribution systems.
• In recent decades, local agencies have developed more diversified sources of water supplies. Many agencies use a combination of imported surface water and local groundwater. They also produce or purchase recycled water for use in irrigating golf courses and other landscaping.
• Many coastal agencies are pursuing ocean desalination projects to further diversify their water supplies or for use on brackish groundwater.
• Some agencies have worked out water transfer agreements in which they purchase water from other agencies.
• Urban and agricultural agencies have invested billions of dollars in water conservation and water use efficiency programs that reduce demand for water. Today, urban Southern California is using less water than it did a few decades ago, even though its population has grown tremendously.
• Water agencies throughout the state are moving toward integrated regional water management planning, which generally includes a mix of programs such as water recycling, water use efficiency, groundwater management and conjunctive use, water transfers, flood protection and watershed management.
• In addition to providing water supplies, many local water agencies have responsibility for providing local flood control and flood protection. Some are responsible for managing and replenishing groundwater basins, while others also treat wastewater.

What Are Watersheds?

• Watersheds are nature’s way of dividing up the landscape.
  
• In simplest terms, a watershed is defined as an area of land that captures rainfall and snowmelt, and then drains into the same place. That place may be a river, lake, estuary, wetland, stream, groundwater basin or even the ocean.
  
• The actions of people who live within a watershed affect the health of the water that drain into it.
  
• Watersheds come in all shapes and sizes. Some are millions of square miles, while others are just a few acres. Some (like the Mississippi River basin) are very large and include many smaller river basins or watersheds. These smaller watersheds can be subdivided into even smaller areas.
  
• Some watersheds cut across county, state and even international borders. Their area can encompass homes, farms, ranches, forests, small towns, big cities and more.
  
• A watershed is a dynamic and unique place. It is a complex web of natural resources, including soil, water, air, plants and animals. We all rely on water and other natural resources to exist.
  
• Everyday activities within a watershed have an impact on its natural resources. Cities, homes, roads and factories modify the watershed and affect its natural resources. Farming, recreation, hydroelectricity generation, mining, construction and forestry can also significantly affect a watershed. All of these impacts ultimately affect our health, our environment, and our economy.

Why Are Watersheds Important?

• Healthy watersheds are vital for a healthy environment and economy. Watersheds provide water for drinking, irrigation and industry as well as hydroelectric power for communities and businesses. They are also important to our recreational needs, providing opportunities to enjoy natural beauty as well as boating, fishing and swimming.
  
• Fish and wildlife also need healthy watersheds for food and shelter.
  
• In recent decades, many people have come to recognize that the best way to protect our vital natural resources is to understand and manage them on a watershed basis. When viewed this way, it’s easy to see that any action taken in a watershed can affect everyone and everything that is part of that watershed’s system.

Watersheds and Water Quality

• Scientists and water managers realize that protecting watersheds is one of the most effective ways to protect and maintain a clean water supply for people and the environment.
  
• In the past, most efforts to address water pollution focused on specific causes or locations such as industrial leaks or sewage discharge sites. Tremendous progress has been made over the past 30 years to detect and control these problems and prevent further pollution from so-called “point sources.”
  
• Today, much of the focus is on “non-point sources,” or pollution that results from a wide variety of activities over a wide area. These sources, which can be harder to identify and measure, can be difficult to control. Parking lots, construction sites, and water that drains from agricultural land or freeways are all sources of “non-point” pollutants that can affect the quality of our water supply.
  
• Watershed partnerships are emerging as a key way to address these water quality problems. With their focus on education and pollution prevention, these partnerships are proving to be more cost-effective than trying to clean up a polluted watershed or remove contaminants from drinking water supplies.
  
• Partnerships can include anyone who lives, works or recreates in the watershed. Likely members include landowners, homeowners, local businesses, developers, recreationists, local government agencies, elected officials, teachers, civic groups and environmental organizations.
  
• Partnerships can establish a sense of cooperation and help identify concerns, educate community members and encourage people to take action to protect their watershed.
  
• Watershed plans developed by local partnerships are often more effective and efficient than other methods such as broad sweeping regulations. The result is the improved environmental and economic health of a watershed.

Snow Pack

• California relies on the snow pack for a major part of its water storage. Annual runoff from the Sierra during April-July averages 14 million acre-feet a year – mostly from snowmelt.
  
• Some climate change models show that climate change could significantly reduce the snow
  pack in the future, thereby diminishing the state’s total water storage capacity. One scenario showed a 2-degree rise in average temperatures could reduce annual runoff by 52%. A 2-degree rise is well within the 1.4-degree to 5-degree increase predicted by some models.

Sea Level

• Sea level as measured at the Golden Gate has risen more than six inches since the early 20 th century. Models predict a median rise of another 1.6 feet over the 21 st century due to climate change.
• In the Delta, some researchers believe sea level could rise as much as 12-16 inches over the coming decades.
• Sea level rise would have a serious effect on the Delta. It could disrupt ecosystems, undermine wetlands restoration efforts, and put even more pressure on the Delta’s fragile levee system, putting at risk the water supply for about 22 million Californians and millions of acres of irrigated farmland.
• Some models show that a single-foot rise in sea level rise in the Delta would increase the frequency of extremely high tides in the Western Delta and increase salinity intrusion from the ocean, degrading freshwater supplies exported from the Delta unless more fresh water is released from upstream reservoirs.
• Coastal aquifers also could be threatened.

Colorado River

History of the Colorado River

• 1922 CO River Compact allocated water among the river’s seven basin states. In addition to its allotted 4.4 MAF share, California was allotted half of all surplus water when available.
• 1928 Boulder Canyon Project Act was authorized for the construction of Hoover Dam, the All-American Canal and Imperial Dam.
• 1931, seven CA entities entered into a permanent contract for the distribution of CA’s 4.4 MAF. The contract specified that 3.85 MAF would go to irrigation districts for agricultural uses. These entities were as follows:
• The City of San Diego
• Coachella Valley Water District
• Imperial Irrigation District
• Los Angeles Department of Water and Power
• Metropolitan Water District of Southern CA
• Palo Verde Irrigation District
• San Diego County

Key Facts About the Colorado River

• Length of River: 1400 Miles
• Source of the CO River is in the Rocky Mountains
• River ends in the Gulf of California in Mexico
• States in the Upper Basin: Wyoming, Utah, Colorado, and New Mexico
• States in the Lower Basin: Arizona, California, Nevada, New Mexico, and Utah
• Lower Colorado River Watershed Area: 246, 000 square miles
• Average Assumed CO River Annual Flow to Lower Basin at Lees Ferry: 15 MAF
• Historic Yearly Flows:
• High: 24 MAF
• Low: 5 MAF
• Amount of Water in an Acre-Foot: 326,000 gallons
• Average Rainfall in Majority of Basin
• 4 inches or less
• Average Power Generated Using CO River Water: 12.2 trillion kilowatts
• Amount of Colorado River Water Allotted to California: 4.4 million acre-feet plus 50% of any declared surplus
• Amount of California’s Share of CO River Water Dedicated to Agriculture: 3.85 MAF
• California Acreage Irrigated by CO River Water: 800,000 acres
• California Irrigation Water Users:
• Imperial Irrigation District
• Coachella Valley Water District
• Palo Verde Irrigation District
• Bard Irrigation District and Indian Agencies

The All-American Canal

• Dimensions
• Overall length 82 miles
• Width 150-200 feet
• Depth 7-20 feet
  
• Capacity
• From Imperial Dam to Siphon Drop Power Plant: 15,155 c.f.s.
• From Siphon Drop Power Plant to Pilot Knob: 13,155 c.f.s.
• From Pilot Knob to Drop No. 1: 10,155 c.f.s.

• The All-American Canal is the Imperial Valley's lifeline from the Colorado River. Approximately 3.1 million acre-feet of Colorado River water is diverted annually into the All-American Canal and delivered to agricultural land and cities.
  
• 70,000 acre-feet per year of water seeps out along a 23-mile section.
  
• The new, lined section will result in the conservation of 67,700 af/yr.
  
• The State of California is paying $135 million for lining the earthen portions of the canal with concrete, in exchange for some of the water saved. Costs above this amount will be paid for by the San Diego County Water Authority, which will receive the conserved water.

IID/San Diego County Water Authority Water Transfer Agreement

• Largest ever transfer of water from agricultural to urban areas.
  
• First 10,000 af flowed to San Diego in 12/03
  
• Under the agreement, the water transfer increases to 200,000 acre-feet annually in year 19 (2022) and stays at that level each year thereafter. It has an initial term of 45 years and a renewal term of 30 years. The transfer represents a new supply of 12.9 million acre-feet of water for San Diego County Water Authority over the 45 or 75-year life of the agreement.

Lower Colorado River Multi-Species Conservation Program

• Cost: $626 million, to be funded by AZ, CA, and NV
  
• A habitat-based conservation program aimed at providing for the conservation of over twenty-seven species, including six that are currently listed as threatened or endangered under the federal Endangered Species Act and eleven species listed as threatened or endangered under the California ESA.
  
• Specific measures include creation of 8,132 acres of habitat, the establishment of mesquite woodlands and cottonwood-willow riparian zones for birds and animals, and the formation of marsh and backwater areas for certain birds and fish. A fish rearing and stocking program also are planned to help increase populations of two endangered fish species.

What is Ocean Desalination?

• Ocean desalination is the process of converting seawater into drinking water. Fresh water is separated from the salty ocean water and used for drinking and other potable water uses. The remaining salts and impurities are then discharged as brine.
  
• There are two main methods for producing desalinated water: distillation and reverse osmosis.
  
• Distillation is the oldest desalination process and has been used throughout the world for centuries. Distillation uses heat to evaporate water and separate it from salt and impurities. The evaporated water is captured and condensed as fresh water. The process is energy-intensive and used primarily in the Middle East and other oil-rich areas of the world.
  
• Reverse osmosis uses membranes to separate fresh water from seawater. Ocean water is forced at very high pressures through a series of membranes, which allow water molecules to pass but not salts and other impurities. The remaining salts and residual water are discharged as brine, typically into the ocean.
  
• Thanks to recent advances in technology, turning ocean water into drinking water is not as energy-intensive as it was a decade ago. These technological developments have reduced the costs and energy requirements of producing desalinated water. In some coastal areas, it is beginning to look like an increasingly feasible way to develop a drought-proof and reliable supply of water.
  
• The desalination process also can be used to remove salt from brackish groundwater or recycled water with a high salt content. The energy required for desalting brackish groundwater is generally less than for ocean desalination.

Facts and Statistics About Ocean Desalination

• According to the U.S. Desalination Coalition, there are more than 11,000 desalination facilities operating in 120 countries around the world. Most of those are located in the Middle East.
  
• In the U.S., there are about 1,200 plants in operation that desalinate either seawater or brackish groundwater. Almost all of the seawater desalination facilities in the United States are small systems used for high-valued industrial or commercial needs. This may change in coming years.
  
• In California, several small-scale pilot ocean desalination plants have been developed in coastal areas such as the San Francisco Bay Area and Southern California.
  
• Currently, there are about 24 desalting plants operating in California that provide water for municipal purposes, with a total capacity of about 79,000 acre-feet. The number includes both seawater and brackish groundwater desalting facilities.
  
• Over the past five years, public agencies and private entities together have put forward more than 20 proposals for large desalination facilities along the California coast. Some of the proposed projects would represent the largest desalination plants in the United States.
  
• If all of those proposed projects were built, the state’s seawater desalination capacity would rise to more than 450 million gallons per day, which would supply roughly 6% of the state’s urban water demand.
  
• The proposed plants range in size from a small facility providing water for a private development in Monterey to much larger plants in Southern California that would rank among the largest desalination plants in the United States.
  
• California communities are pursuing desalination for a variety of reasons. For Southern California, a key factor driving interest is population growth, the need for drought reliability and a desire to reduce reliance on imported water supplies.
  
• On the Central Coast, local water supply limitations, growth and drought concerns are prompting many agencies to consider seawater desalination.
  
• In Northern California, where four desalination plants are proposed, agencies are seeking improved water reliability during droughts and emergencies as well as additional supplies for growing service areas.
  
• Although the cost and energy requirements are coming down, ocean desalination is still a costly endeavor. There are also potential environmental impacts associated with ocean intakes that bring water into plants and the disposal of brine produced in the desalination process.

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What is Water Recycling?

• Water recycling is defined as the planned reuse of treated wastewater for purposes such as landscape irrigation or toilet flushing. It is sometimes called water reuse or water reclamation.

• Though many people associate the word “recycling” with glass bottles and aluminum cans, the fact is California water agencies and communities have been recycling water for decades with great success. With scores of new recycling projects in the planning stages, the amount of water recycled in California is expected to double in the near future.

• Water recycling has many benefits. It reduces demands for freshwater supplies, and cuts down on pollution and wastewater discharges into sensitive rivers, bays and estuaries. It also allows communities to stretch existing water supplies and reduce their reliance on water imported from other areas.

• Recycled water can also be used to create or enhance wetlands and riparian habitats.

• As California’s population continues to grow, water recycling will play a key role in meeting water needs. It will be one component of a diverse mix of strategies that include water use efficiency, desalination, groundwater management, water transfers and more.

Facts and Statistics about Water Recycling

• Over 525,000 acre-feet of wastewater is recycled annually in California. That frees up enough freshwater to meet the needs of more than 1 million typical households.

• There are more than 250 water recycling projects in operation today. More are coming online each year.

• In the coming years, experts say water recycling efforts will greatly expand with a goal of generating over 1 million acre-feet of water each year. That level of recycling will go a long way toward meeting the needs of the 17 million additional residents California will have by 2030.

• Today, recycled water is used for a variety of purposes. It is used to irrigate lawns, landscaping, golf courses, crops and freeway medians, replenish groundwater basins and act as a barrier to seawater intrusion. In office buildings, it is used to flush toilets and urinals.

• Recycled water is also increasingly being used by industry in cooling processes and for other purposes such as carpet dyeing, recycled newspaper processing and laundries.

• Nearly one-half (48%) of the state’s recycled water is used for agricultural irrigation. Another 20% is used for landscape irrigation, and about 12% is for groundwater recharge.

• At least 20 varieties of food crops are grown with recycled water, including vegetables such as lettuce and celery. Eleven non-food crops, such as pasture and alfalfa for animals, as well as flowers and nursery products are irrigated with recycled water.

• Over 125 golf courses in California are irrigated with recycled water today, as well as numerous parks, schoolyards, and freeway medians.

• In many areas long the coast, recycled water is injected into groundwater aquifers to create barriers to prevent seawater from intruding into inland.

The History of Water Recycling

• Water recycling in California dates back to as early as 1890, when wastewater was used for agricultural irrigation in the Central Valley.

• By 1910, at least 35 communities were using wastewater to irrigate farmland.

• Landscape irrigation with treated wastewater began in Golden Gate Park in San Francisco in 1912.

• By 1952, there were 107 communities using recycled water to irrigate farms and landscape.

• Over time, wastewater treatment and recycling processes have greatly improved to protect public health.

• Through the natural water cycle, the earth has recycled and reused water for millions of years.