Lewis HUC8 17080002
A 2,716 km² sub-basin of the Pacific Northwest region in WA. Drought coverage is from the US Drought Monitor (map of 2026-09-01); streamflow classes place each USGS gauge's latest reading against its own day-of-year record.
Health score
69
Moderate
Drought index
100
Moderate
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
33%
of 6 reporting
Median flow
91%
p40 of record
Water assets
2,170
269 springs · 804 wells
USGS gauges (6)
- LEWIS RIVER ABOVE MUDDY RIVER NEAR COUGAR, WA14216000208 cfsp9 · much below normal
- MUDDY RIVER BELOW CLEAR CREEK NEAR COUGAR, WA14216500126 cfsp21 · below normal
- SPEELYAI CREEK NEAR COUGAR, WA142198002 cfsp31 · normal
- EAST FORK LEWIS RIVER NEAR HEISSON, WA1422250059 cfsp49 · normal
- LEWIS RIVER AT ARIEL, WA142205001,290 cfsp51 · normal
- CANYON CREEK NEAR AMBOY, WA1421900032 cfsp65 · normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 100 | 0 | 2/6 | p40 |
Top water assets
- 76Ir — Ce S2-*11791Cwrisspring
- 76Ir St — Ce S2-21907Alcwrisspring
- 76Fp Ir — Ap S2-28836spring
- 76Fs — Ap S2-30553spring
- 76Fs — Ap S2-30556spring
- 76Fs — Ap S2-30414spring
- 76Ir — Ce S2-25465Gwrisspring
- 76Po — Ap S2-28278spring
- 76Ci Ir — Ce S2-*20093Cwrisspring
- 73Ir — Ce S2-25912Gwrisspring