St. Clair HUC8 04090001
A 3,276 km² sub-basin of the Great Lakes region in CN, MI. 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
74
Moderate
Drought index
100
Moderate
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
0%
of 4 reporting
Median flow
229%
p79 of record
Water assets
593
2 springs · 83 wells
USGS gauges (4)
- ST. CLAIR RIVER AT PORT HURON, MI04159130197,000 cfsp27 · normal
- BELLE RIVER AT MEMPHIS, MI0416060022 cfsp76 · above normal
- MILL CREEK NEAR AVOCA, MI0415990021 cfsp82 · above normal
- BLACK RIVER NEAR JEDDO, MI04159492105 cfsp92 · much above normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 100 | 0 | 0/4 | p79 |
Top water assets
- 66Fords Damreservoir
- 65Dte Energy Greenwood Cooling Reservoirreservoir
- 65Mill Creek Structurereservoir
- 65Black River Near Jeddo, Miriver
- 65Duffy Pond Damreservoir
- 65St. Clair River At Port Huron, Miriver
- 65Belle River At Memphis, Miriver
- 65Mill Creek Near Avoca, Miriver
- 65Hodder Damreservoir
- 65Squier Damreservoir