TidalMapPatuxent River near Unity, MD Water Level Today
NWS river forecast
| When | Stage | Flow |
|---|
Forecast from the NOAA National Water Prediction Service. Issued a few times a day and only while a forecast is active. Not for navigation.
Last 30 days
About this gauge
USGS gauge 01591000 sits on the Patuxent River and reads everything draining 35 square miles of the Patuxent basin. Its datum sits 364 feet above sea level NAVD88. Daily flow has been on record here since 1944, 82 years of it.
Where this gauge sits in the drainage
No gauged site sits above this one on the mainstem, so this is the first published reading on the river. Downstream the next reading comes from Patuxent River below Brighton Dam near Brighton MD at 79 square miles, so what passes this gauge is about 44% of the water measured there. Water passing here goes on to Patuxent River near Laurel, MD and Patuxent River near Bowie, MD.
Normal flows here
The Patuxent River runs a median of 26 cfs at this gauge across 82 years of record. March is the fullest month at a median 47 cfs, and September the leanest at 12 cfs. The highest daily mean on record is 2,590 cfs in 1975, and the lowest is 0.2 cfs in 1966.
| Month | Median flow | Share of annual median |
|---|---|---|
| Jan | 34 cfs | 133% |
| Feb | 41 cfs | 161% |
| Mar | 47 cfs | 184% |
| Apr | 46 cfs | 178% |
| May | 36 cfs | 141% |
| Jun | 25 cfs | 98% |
| Jul | 17 cfs | 67% |
| Aug | 14 cfs | 55% |
| Sep | 12 cfs | 47% |
| Oct | 14 cfs | 55% |
| Nov | 18 cfs | 71% |
| Dec | 26 cfs | 102% |
Medians from the USGS daily-statistics record, 1944 to 2026. A month at 100% is running at its own long-term median.
Flood stages and record crests
The Patuxent River reaches flood stage at this gauge at 8 feet. NWS starts watching it at 7 feet. The highest crest on record is 18.6 feet, in September 1971.
| Category | Gage height |
|---|---|
| Action | 7 ft |
| Minor flooding | 8 ft |
| Moderate flooding | 11 ft |
| Major flooding | 18 ft |
| When | Crest |
|---|---|
| September 1971 | 18.6 ft |
| June 1972 | 16.1 ft |
| July 1956 | 14.3 ft |
| August 1945 | 13.6 ft |
| September 1975 | 12.7 ft |
Flood categories and crest history from the NOAA National Water Prediction Service, gauge PRUM2. Stages are gage height, not depth. Not for navigation.
Nearby river gauges
- Cattail Creek near Glenwood, MD
- Patuxent River below Brighton Dam near Brighton MD
- Hawlings River near Sandy Spring, MD
- Paint Branch Tributary near Colesville, MD
- Turkey Branch near Rockville, MD
- Northwest Branch Anacostia River near Colesville, MD
- Little Seneca Creek Tributary at Brink, MD
- Little Seneca Creek Tributary near Clarksburg, MD
- Little Patuxent River at Guilford, MD
- Patuxent River near Laurel, MD
- Little Seneca Creek Tributary near Germantown, MD
- Paint Branch near College Park, MD
Live streamflow and gage height: USGS gauge 01591000. Percentile context computed against the gauge's period of record. Not for navigation.
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