St. Marys HUC8 04100004
A 2,054 km² sub-basin of the Great Lakes region in IN, OH. 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
83
Healthy
Drought index
0
None
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
17%
of 6 reporting
Median flow
155%
p58 of record
Water assets
386
0 springs · 90 wells
USGS gauges (11)
- SPY RUN CREEK NEAR PARK DRIVE AT FORT WAYNE, IN041828081 cfsp19 · below normal
- ST. MARYS RIVER AT MAIN ST. AT FORT WAYNE, IN0418276979 cfsp34 · normal
- ST. MARYS RIVER NEAR FORT WAYNE, IN0418200058 cfsp56 · normal
- St Marys River at Walcot Street at Willshire OH0418104938 cfsp60 · normal
- ST. MARYS RIVER AT DECATUR, IN0418150070 cfsp62 · normal
- St. Marys River at Rockford OH0418098849 cfsp67 · normal
- BLUE CREEK NR PLEASANT MILLS, IN04181100no readingno long-term record
- ST. MARYS RIVER AT PLEASANT MILLS, IN0418112051 cfsno long-term record
- JUNK DITCH AT FORT WAYNE, IN04182755-2 cfsno long-term record
- DRAIN TILE NORTH OF CR 1000 N NR DECATUR, IN4053270845554010 cfsno long-term record
- OVERLAND FLOW NORTH OF CR 1000 N NR DECATUR, IN4053270845554020 cfsno long-term record
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-10-20 | 0 | 0 | 1/6 | p58 |
| 2026-10-19 | 0 | 0 | 0/7 | p59 |
| 2026-10-18 | 0 | 0 | 0/7 | p61 |
| 2026-10-17 | 0 | 0 | 0/7 | p76 |
| 2026-10-16 | 0 | 0 | 0/7 | p65 |
| 2026-10-15 | 0 | 0 | 0/7 | p77 |
| 2026-10-14 | 0 | 0 | 0/6 | p73 |
| 2026-10-13 | 0 | 0 | 0/6 | p71 |
| 2026-10-12 | 0 | 0 | 0/6 | p68 |
| 2026-10-11 | 0 | 0 | 0/7 | p72 |
| 2026-10-10 | 0 | 0 | 0/7 | p69 |
| 2026-10-09 | 0 | 0 | 0/7 | p79 |
| 2026-10-08 | 0 | 0 | 0/7 | p80 |
| 2026-10-07 | 0 | 0 | 0/6 | p86 |
Top water assets
- 65St. Marys River At Rockford Ohriver
- 65Blue Creek Nr Pleasant Mills, Inriver
- 65St. Marys River At Main St. At Fort Wayne, Inriver
- 65Spy Run Creek Near Park Drive At Fort Wayne, Inriver
- 65St. Marys River At Pleasant Mills, Inriver
- 65St. Marys River At Decatur, Inriver
- 65Blue Creekriver
- 65St. Marys River Near Fort Wayne, Inriver
- 65St Marys River At Walcot Street At Willshire Ohriver
- 65Forty Acre Pond Damreservoir