Sacramento Water Supply: Rivers, Wells, Districts

Which rivers supply Sacramento water?

The American River and the Sacramento River supply most Sacramento-region tap water. The City of Sacramento treats American River water at its E.A. Fairbairn plant and Sacramento River water at its Sacramento River plant, together about 80% of its supply in 2025.

East of the City, suppliers draw from Folsom Lake on the American River: San Juan Water District, Folsom, Roseville and El Dorado Irrigation District each run their own plants. West and south, West Sacramento, the Sacramento County Water Agency's Vineyard plant and the Woodland-Davis Clean Water Agency all take Sacramento River water. The full story for City water, from intake to tap, is on where Sacramento tap water comes from.

How much Sacramento water supply is groundwater?

It depends on the supplier, from none to all of it. The City of Sacramento pumps about 20%, Carmichael about 30% in a typical year, and Rio Linda/Elverta 100%; Orange Vale and San Juan's retail area use none.

Groundwater is usually the harder, more mineral-rich share. City wells test at 15–154 mg/L hardness against 34 mg/L for its American River water, and Sacramento Suburban Water District's wells averaged 120–130 mg/L in its 2025 report. Wells also carry most of the region's hexavalent chromium, which California limits to 10 µg/L under rules on the State Water Board's chromium 6 page.

Which district supplies your address?

Your water bill names your supplier; if water comes through rent or HOA dues, Sacramento County's address search returns it. More than 20 suppliers serve the county, and boundaries do not follow city limits: Rancho Cordova and Elk Grove addresses can each fall in more than one system.

The difference matters at the tap. El Dorado Irrigation District's water tested at 13 mg/L hardness in 2025, while Cal Am's Fruitridge Vista system averaged 172 mg/L, per the 2025 report listed on Cal Am's report index. The district-by-district breakdown is on which Sacramento water district serves you.

How do you read a supplier's report?

Start with each row's average and range, compare them with the MCL, then read the hardness, lead and unregulated tables. Every supplier publishes a yearly Consumer Confidence Report; the City's 2025 edition came out June 1, 2026, and West Sacramento's latest posted edition is from 2024.

Reports use ppm, ppb and ppt, which equal mg/L, µg/L and ng/L. They list only what was detected, and ND means below the reporting limit, not zero. The report-reading walk-through uses the City's own tables as the worked example.

What about private wells?

Private wells are the owner's responsibility: Sacramento County permits well construction and repair, but the State Water Board's GAMA program says the state does not regulate water quality in most private domestic wells. It recommends testing yearly for total coliform bacteria, nitrate and electrical conductivity.

Basic lab analysis typically costs $100–400, per the State Water Board, and certified labs are listed on its ELAP map. Nearby public wells show which rows to watch, especially nitrate, arsenic and hexavalent chromium. See private well testing in Sacramento County for the full schedule and limits.

• Supply: River to tap: the City's sources and plants
• Supply: Find your supplier and compare districts
• Supply: MCL, PHG and the rows that matter
• Supply: Well tests, limits and certified labs

Downstream questions