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 2026-10-13); 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
25%
of 4 reporting
Median flow
80%
p37 of record
Water assets
593
2 springs · 83 wells
USGS gauges (4)
- BLACK RIVER NEAR JEDDO, MI0415949215 cfsp19 · below normal
- BELLE RIVER AT MEMPHIS, MI0416060014 cfsp27 · normal
- MILL CREEK NEAR AVOCA, MI0415990013 cfsp46 · normal
- ST. CLAIR RIVER AT PORT HURON, MI04159130202,000 cfsp55 · normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-10-19 | 100 | 0 | 1/4 | p37 |
| 2026-10-18 | 100 | 0 | 0/4 | p46 |
| 2026-10-17 | 100 | 0 | 0/4 | p44 |
| 2026-10-16 | 100 | 0 | 2/4 | p27 |
| 2026-10-15 | 100 | 0 | 2/4 | p24 |
| 2026-10-14 | 100 | 0 | 2/4 | p26 |
| 2026-10-13 | 100 | 0 | 1/4 | p36 |
| 2026-10-12 | 100 | 0 | 0/4 | p43 |
| 2026-10-11 | 100 | 0 | 0/4 | p41 |
| 2026-10-10 | 100 | 0 | 0/4 | p54 |
| 2026-10-09 | 100 | 0 | 1/4 | p40 |
| 2026-10-08 | 100 | 0 | 0/4 | p50 |
| 2026-10-07 | 100 | 0 | 0/4 | p49 |
| 2026-10-06 | 100 | 0 | 0/4 | p57 |
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