Oakland
Oakland, CA water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
east bay mud
surface water (rivers/reservoirs) · local government · PWSID CA0110005
Below EPA's 15 ppb lead action level at last testing.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1
Oakland is a large city and the 8th-largest in California, home to roughly 419,267 residents. Oakland's drinking water comes largely from the same regional sources that serve California: Sierra snowpack, Colorado River, State Water Project, and groundwater.
As elsewhere in California, the central challenge is drought. Orange County runs the world's largest groundwater replenishment system, and the state adopted direct potable reuse rules in 2023 — but the Central Valley's groundwater overdraft remains severe.
California reuses an estimated 23% of its treated wastewater and maintains established reuse programs; Oakland tracks abnormally dry to moderate drought conditions on the U.S. Drought Monitor scale.
Explore the California profile for statewide context, or dig into the water issues shaping Oakland below.
Alameda County water quality
Source: EPA SDWIS · 2026 Q1
At a glance
- Population ~419,267 (8th-largest in California)
- Primary sources: Sierra snowpack, Colorado River, State Water Project, and groundwater
- Drought: abnormally dry to moderate conditions
- State reuse rate: ~23% of wastewater
Statewide drought history
% of California in severe+ drought (Moderate (D1) now).
Source: U.S. Drought Monitor
Common questions
Is tap water safe in Oakland?
Oakland's largest water system, EAST BAY MUD, serves about 1,442,800 people. EPA records show 0 health-based violation(s) since 2016 and a most-recent 90th-percentile lead level of 0 ppb (EPA action level is 15 ppb). Always check your own provider's annual Consumer Confidence Report.
Where does Oakland get its water?
EAST BAY MUD draws primarily from surface water (rivers/reservoirs), part of California's supply from Sierra snowpack, Colorado River, State Water Project.
Related water issues
Drought
Much of the American West is in a multi-decade dry period that researchers describe as the most severe in over a millennium, reshaping how communities plan for water.
ExploreColorado River
The river that supplies 40 million people has lost roughly a fifth of its flow since 2000, forcing a renegotiation of how seven states share the water.
ExploreGroundwater Depletion
Aquifers from the Central Valley to the Ogallala are being pumped faster than they recharge, causing land subsidence and threatening long-term supply.
ExplorePotable Reuse
Advanced purification turns treated wastewater into water that meets or exceeds drinking-water standards — increasingly essential in water-stressed regions.
Explore