Tigard Water Hardness & Quality Report (2026)

Tigard, Oregon, in Washington County southwest of Portland — a major Portland southwest suburban community known for Bridgeport Village (one of Oregon's premier retail centers), Washington Square Mall, and a diverse community with significant Korean-American and Vietnamese-American populations — draws its municipal water supply from the Tualatin River (Hagg Lake Reservoir) and supplemental Portland Water Bureau supplies via the Tualatin Valley Water District (TVWD) and the City of Tigard Water Division. Water hardness in Tigard measures 38.5 mg/L — classified as very soft.

Tigard's very soft supply reflects the Tualatin Valley watershed's Oregon Cascade and Coast Range volcanic terrain. The Tualatin River above Hagg Lake–Forest Grove drains: the Oregon Coast Range (Eocene Tillamook Volcanics — submarine basalt flows of the Coast Range, calcium-poor mafic rock); the Tualatin Mountains (the west Portland hills — Eocene Waverly Heights Basalt and Aloha Basalt — mafic basalt flows, calcium-poor); and the Cascade Range foothills (Quaternary basalt and andesite volcanic outwash — mafic, calcium-poor). The dominant Oregon Coast Range and Cascade volcanic terrain produces the very soft 38.5 mg/L at Tigard.

With hardness at 38.5 mg/L, Tigard residents enjoy very soft water with essentially no scale challenges. Tualatin Valley Water District and City of Tigard Water Division consistently deliver water meeting all Oregon DEQ and EPA Safe Drinking Water Act requirements.