Upper Chehalis HUC8 17100103
A 3,364 km² sub-basin of the Pacific Northwest region in WA. Drought coverage is from the US Drought Monitor (map of 2026-10-13); streamflow classes place each USGS gauge's latest reading against its own day-of-year record.
Health score
58
Moderate
Drought index
5
Abnormally dry
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
83%
of 12 reporting
Median flow
46%
p11 of record
Water assets
4,994
25 springs · 4,886 wells
USGS gauges (12)
- SKOOKUMCHUCK RIVER NEAR VAIL, WA1202570015 cfsp7 · much below normal
- SOUTH FORK NEWAUKUM RIVER NEAR ONALASKA, WA1202400022 cfsp8 · much below normal
- CHEHALIS RIVER NEAR DOTY, WA1202000027 cfsp9 · much below normal
- NEWAUKUM RIVER NEAR CHEHALIS, WA1202500038 cfsp9 · much below normal
- CHEHALIS RIVER AT PORTER, WA12031000346 cfsp10 · much below normal
- NF NEWAUKUM RIVER ABOVE BEAR CREEK NEAR FOREST, WA1202440010 cfsp11 · below normal
- CHEHALIS RIVER NEAR ADNA, WA1202180055 cfsp12 · below normal
- CHEHALIS RIVER NEAR GRAND MOUND, WA12027500240 cfsp14 · below normal
- ELK CREEK BELOW DEER CREEK NEAR DOTY, WA1202052519 cfsp16 · below normal
- SKOOKUMCHUCK RIVER BL BLDY RUN CR NR CENTRALIA, WA12026150108 cfsp22 · below normal
- SKOOKUMCHUCK RIVER NEAR BUCODA, WA12026400108 cfsp34 · normal
- SOUTH FORK CHEHALIS RIVER NEAR WILDWOOD, WA1202080018 cfsp44 · normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-10-20 | 5 | 0 | 10/12 | p11 |
| 2026-10-19 | 5 | 0 | 10/12 | p15 |
| 2026-10-18 | 5 | 0 | 8/11 | p15 |
| 2026-10-17 | 5 | 0 | 9/12 | p13 |
| 2026-10-16 | 5 | 0 | 9/12 | p14 |
| 2026-10-15 | 5 | 0 | 10/12 | p16 |
| 2026-10-14 | 5 | 0 | 10/12 | p17 |
| 2026-10-13 | 5 | 0 | 8/12 | p20 |
| 2026-10-12 | 5 | 0 | 7/12 | p21 |
| 2026-10-11 | 5 | 0 | 6/12 | p25 |
| 2026-10-10 | 5 | 0 | 5/12 | p25 |
| 2026-10-09 | 5 | 0 | 6/12 | p23 |
| 2026-10-08 | 5 | 0 | 7/12 | p24 |
| 2026-10-07 | 5 | 0 | 5/12 | p28 |
Top water assets
- 76Ir — Ap S2-30113spring
- 76Mu — Ap S2-30405spring
- 76Ir — Ap S2-29380spring
- 67Skookumchuckreservoir
- 66Ir — Ap S2-29760spring
- 66Ds Po — Ap S2-29167spring
- 66Ir St — Ap S2-29762spring
- 66Ir — Ap S2-29614spring
- 65Centralia Coal Mine Pond 46 Damreservoir
- 65Centralia Coal Mine Dam No 3Breservoir