River WA

Sammamish River

Washington • 47.7543, -122.2506

Hydrography profile Updated Dec 27, 2025

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USGS and NOAA data is for informational purposes. Source notes

Length

14 mi

22 km

Elevation

29′ → 16′

13 ft drop

Stream Order

Large River

Slope

0.02%

1.0 ft/mi

Drainage

243 mi²

631 km²

Avg Flow

450 cfs

1.3 mph velocity

Path to Mouth

30 mi

48 km to ocean

Classification

Tributary

Mid-reach

Elevation Profile

Water Quality

Data from EPA Water Quality Portal (USGS, EPA, state agencies).

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Data from USGS & NOAA for informational purposes only. Read source and safety notes

Access Sites on Sammamish River

There are 1 boat ramps, launches, and public access points on Sammamish River.