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Water in Solano County

Where our water comes from

The Solano County Water Agency provides untreated water to the cities and agricultural districts of Solano County from two sources: the Solano Project delivers water from the Putah Creek watershed, including Lake Berryessa and Lake Solano; the North Bay Aqueduct delivers water from the Sacramento-San Joaquin Delta to both Napa and Solano Counties. The Solano Irrigation District (SID) delivers Solano Project water to various contracted users throughout the County, including four of Solano County’s seven cities, as well as the members of the irrigation district. This water is used for both drinking and agriculture. Benicia uses water from the North Bay Aqueduct and other local sources. Rio Vista uses Sacramento River water as its main water supply. Dixon uses ground water exclusively for the older parts of town and partners with SID to supply water to the newer development. Suisun City partners with SID, and all water used in the city comes from the Solano Project. The cities of Vacaville, Fairfield and Vallejo rely on both Solano Project and North Bay Lake Solano from canoe Aqueduct water for their water supply. Vallejo also draws water from two lakes owned by the city.

In some cases, SID manages and delivers well water to groups of rural users. Other rural homes draw their water from private wells.

Availability of a good quality and reliable water source is essential to the operations of many businesses in the County. Large water users in the county include Anheuser-Busch in Cordelia, and Genentech in Vacaville. Water is also used in manufacturing, at the State Medical Facility in Vacaville, at UC Davis (which straddles Yolo and Solano Counties) and by agricultural operations big and small.

Presently, the Solano Project is able to supply enough water to all its contracted users. Solano County is fortunate that Lake Berryessa has had great water storage for the last several years, sparing them the water delivery cutbacks suffered by many users of Sierra Nevada water. As Solano County continues to grow, water will become a bigger issue. Some private ground water users are struggling with adequate and reliable water supply. Citizens and local governments in all the County’s watersheds will likely need to consider the availability and cost of water as they approve new development or land usage changes.

Where water goes after we use it

After we use water, it returns to the watershed in one of two ways. The water used outside – for wetland shore bird_SRCD irrigation, car washing, agriculture, etc., either is absorbed into the soil or becomes runoff, moving along the natural and man-made flow routes in the watershed. If you live in an area with streets and storm drains, most of the water that runs off your property will end up in one of these engineered drainage systems, where it will eventually flow untreated into the Sacramento River, Suisun Marsh, Napa River or the Carquinez Strait, depending on where you live. If you live in a rural area, your outside water will also flow along natural and man-made routes, such as culverts and ditches and eventually drain into either the Sacramento River or the Suisun Marsh.

The path tap water takes to return to the watershed also varies, depending on where you live. Urban residents who are hooked up to a municipal water system send their used water into the City’s sewage system, where it is treated to exacting standards at a wastewater treatment plant and then released back into a canal or creek to make it’s way to the river, Marsh or Carquinez Strait. Rural residents send their used water into their property’s septic tank, where the system’s enzymes break down solid wastes and toxins and the cleaned water eventually leaches down into the ground water supply.

Water Quality- Keeping our streams and Drinking water clean and safe

Good water quality is an essential piece of a healthy watershed. Multiple agencies in Solano County have regulatory responsibility for maintaining water quality, including the Solano County Water Agency (through its Integrated Water Resources Management Plan, or IWRMP), Solano Irrigation District, all County Sewer Districts and each of the County’s seven cities.

As water from rainfall and irrigation flows over and through our watersheds, it picks up and carries contaminants from many different sources. This is called Non-Point Source pollution, which is the term regulators use for polluted runoff. This polluted water ends up in streams, lakes and the ocean by flowing directly in or by going through untreated storm drains. Water also carries pollutants into underground drinking water sources as it soaks into the ground.

Here are some things you can do to prevent non-point source pollution from damaging our water quality:

Reduce the amount of water, fertilizers and pesticides you use. Excess water can carry contaminants directly to our creeks and into the Delta system.

Wash your car at a commercial car wash where the dirty water will be treated by the sewer district, or on a permeable surface such as the lawn to keep detergents and street trash from entering the storm drain system.

Fit your roof with gutters and downspouts that discharge onto a permeable surface (such as grass or a sand-pit), or collect rainwater in a cistern or tank for fire protection and irrigation.