RIVER GAUGE · ST. MARYS RIVER
St. Marys River at Great Mills
St. Marys County, Maryland
Water level1.40 ft
Flow5 cfs
Last readingSep 16, 2026, 4:15 PM UTC (last recorded)
Action5 ft
Minor flood7 ft
Moderate flood8 ft
Major flood10 ft
The past week
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What floods at each level
- 10 ft
Widespread flooding is occurring in Great Mills with water approaching homes and businesses.
- 8 ft
Indian Bridge Road begins to flood as flooding becomes more widespread in Great Mills.
- 7 ft
Flat Iron Road begins to flood with water in some yards in Great Mills.
Highest crests on record
| Date | Level | Flow |
|---|---|---|
| Aug 19, 1969 | 13.34 ft | 7,950 cfs |
| Aug 28, 2011 | 12.98 ft | 6,960 cfs |
| Sep 15, 1999 | 12.82 ft | 6,560 cfs |
Get an alert when St. Marys River rises
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