Gresham
Gresham, OR water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
gresham, city of
surface water (rivers/reservoirs) · local government · PWSID OR4100357
Below EPA's 15 ppb lead action level at last testing.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1
Gresham is a mid-sized city and the 4th-largest in Oregon, home to roughly 110,553 residents. Gresham's drinking water comes largely from the same regional sources that serve Oregon: Cascade snowpack, Willamette River, Columbia River, and groundwater.
As elsewhere in Oregon, the central challenge is drought. The wet west and arid east create a split state; the Klamath Basin is a flashpoint for water allocation.
Oregon reuses an estimated 12% of its treated wastewater and maintains developing reuse programs; Gresham tracks severe to extreme drought conditions on the U.S. Drought Monitor scale.
Explore the Oregon profile for statewide context, or dig into the water issues shaping Gresham below.
Multnomah County water quality
Source: EPA SDWIS · 2026 Q1
At a glance
- Population ~110,553 (4th-largest in Oregon)
- Primary sources: Cascade snowpack, Willamette River, Columbia River, and groundwater
- Drought: severe to extreme conditions
- State reuse rate: ~12% of wastewater
Statewide drought history
% of Oregon in severe+ drought (Extreme (D3) now).
Source: U.S. Drought Monitor
Common questions
Is tap water safe in Gresham?
Gresham's largest water system, GRESHAM, CITY OF, serves about 73,932 people. EPA records show 0 health-based violation(s) since 2016 and a most-recent 90th-percentile lead level of 3.4 ppb (EPA action level is 15 ppb). Always check your own provider's annual Consumer Confidence Report.
Where does Gresham get its water?
GRESHAM, CITY OF draws primarily from surface water (rivers/reservoirs), part of Oregon's supply from Cascade snowpack, Willamette River, Columbia River.
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.
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