Sandy River Basin – Streamflow, Reservoir & Stage Gages

About the Sandy River Basin

The Sandy River drains about 500 square miles on the west side of Mount Hood, flowing about 56 miles from the Reid and Sandy glaciers to the Columbia River at Troutdale, east of Portland. Glacier melt gives the upper river its milky summer color, and the Salmon and Zigzag rivers join it near Brightwood and Welches. Marmot Dam, near the Marmot gage, was removed in 2007, leaving the Sandy free-flowing from the mountain to the Columbia; the lower river through the Sandy River Gorge to Oxbow and Dabney parks is popular for drift boats, kayaks, swimming and winter steelhead and spring Chinook fishing. The Bull Run River, the Sandy’s largest tributary, is the City of Portland’s main drinking-water source; its watershed is closed to public entry, and two water-supply dams form Bull Run Reservoirs No. 1 and No. 2. The Oregon Water Resources Department’s Sandy Basin also includes the Oregon streams of the Columbia River Gorge east to Bonneville Dam. River Flow Planner covers 18 gages here: long USGS streamflow records such as the Sandy River near Marmot (since 1911) and the Bull Run River near Bull Run (since 1907), the Bull Run watershed gages, Bull Run Lake and reservoir levels, the Oregon Water Resources Department’s Salmon River gage near Government Camp, and the Columbia River stage below Bonneville Dam.

What River Flow Planner shows for each gage

Each gage page turns the agency’s full daily record into planning tools for fishing, rafting, kayaking, swimming, boating, irrigation and in-stream work:

• Summary hydrograph of typical flows, river stages or lake levels through the year
• Percent of time flows fall within a range you choose
• Likely range of flows on future dates you pick
• How a recent period compares with normal, plus a year-by-year spaghetti plot
• Flood frequency statistics for USGS gages with peak-flow records
• CSV downloads and links to current real-time data and short-term forecasts

Sandy & Salmon Rivers

Listed upstream to downstream.

Bull Run River

The Bull Run River is the City of Portland’s drinking-water source; the watershed above the lower river is closed to public entry. Listed upstream to downstream.

Bull Run Tributaries

Small tributaries of the Bull Run River, including the Little Sandy River.

Lower Sandy & Columbia River

Beaver Creek and Kelly Creek near Troutdale and Gresham, and the Columbia River below Bonneville Dam.

Lake & Reservoir Levels

Daily midnight water-surface elevations of Bull Run Lake and the two Bull Run water-supply reservoirs.

Other basins

Rogue River Basin · Klamath River Basin · Deschutes River Basin · North Coast Basin · Mid Coast Basin · Umpqua River Basin · South Coast Basin · Willamette River Basin · Hood River Basin · John Day River Basin · Umatilla River Basin · Grande Ronde River Basin · Powder River Basin · Malheur River Basin · Owyhee River Basin · Malheur Lake Basin · Goose & Summer Lakes Basin