Waterlands
St Marys River
USGS · 01661500
ST MARYS RIVER
USGS · 01661500LIVE

ST MARYS RIVER AT GREAT MILLS, MD

SAINT MARY'S COUNTY, MD38.2418°N, -76.5037°W Updated 23 hr ago
FLOW RATE
30cfs
Flow Rate Historical Avg
MEDIAN FLOW RATE · 30 DAY
30cfs 75.8% vs avg
Optimal band: 2–2 cfs
PERIOD HIGH
30cfs
PERIOD LOW
1cfs
RUNNABLE
55%
last 30 day in band
Precipitation History
Your History · ST MARYS RIVER AT GREAT MILLS, MD

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Station Location

38.2418, -76.5037
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DATA · USGS · NOAA · NWSUPDATED 2026-07-07 00:00 UTC
Site #01661500·USGS

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