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Tap water and supply

Where your water comes from and who sends it. 4 items.

Tap water and supplyWater map: your supplier, watershed and groundwaterEnter an address or click the map. We show who supplies your water, which watershed you live in, and which groundwater basin is under you.Updated Oct 11, 2026

Tap water and supplyWhere Sonoma County tap water comes fromMost tap water served by Sonoma Water starts in the Russian River system. It is pulled from the ground beside the river, treated lightly, and piped to your city or district.Tap water and supplyIs your Sonoma County water safe to drink? City, well, tank, creek and rainCity water is disinfected with chlorine, and Sonoma Water and Santa Rosa say they add no fluoride. Wells, tanks, creeks and rain have no one testing them for you. Look up your supplier, then find your source below.Tap water and supplyWater filters: what to buy for city, well and rural waterFor city water, a certified carbon filter takes out chlorine. A pitcher is the cheapest start and an under-sink unit is the better long-term choice. For a well, test first, then match the filter. For germs from a well, tank, creek or rain, add a sediment filter and UV.