TidalMapBynum Run at Bel Air, 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 01581500 sits on Bynum Run and reads everything draining 8.5 square miles of the Gunpowder-Patapsco basin. Its datum sits 250 feet above sea level NAVD88. Daily flow has been on record here since 1944, 47 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 Bynum Run near Abingdon, MD at 21 square miles, so what passes this gauge is about 41% of the water measured there.
Normal flows here
Bynum Run runs a median of 5.5 cfs at this gauge across 47 years of record. March is the fullest month at a median 9.7 cfs, and September the leanest at 2.4 cfs. The highest daily mean on record is 1,320 cfs in 1999, and the lowest is 0.0 cfs in 2002.
| Month | Median flow | Share of annual median |
|---|---|---|
| Jan | 7.4 cfs | 136% |
| Feb | 8.8 cfs | 161% |
| Mar | 9.7 cfs | 178% |
| Apr | 8.4 cfs | 153% |
| May | 6.6 cfs | 121% |
| Jun | 4.4 cfs | 81% |
| Jul | 3.2 cfs | 59% |
| Aug | 2.9 cfs | 53% |
| Sep | 2.4 cfs | 44% |
| Oct | 3.4 cfs | 62% |
| Nov | 4.7 cfs | 85% |
| Dec | 7.2 cfs | 132% |
Medians from the USGS daily-statistics record, 1944 to 2025. A month at 100% is running at its own long-term median.
Flood stages and record crests
Bynum Run reaches flood stage at this gauge at 9 feet. NWS starts watching it at 6 feet. The highest crest on record is 11.2 feet, in August 2016.
| Category | Gage height |
|---|---|
| Action | 6 ft |
| Minor flooding | 9 ft |
| Moderate flooding | 13 ft |
| Major flooding | 17 ft |
| When | Crest |
|---|---|
| August 2016 | 11.2 ft |
| September 1999 | 9.9 ft |
| August 2017 | 9.3 ft |
| June 2006 | 9.2 ft |
| June 2021 | 9.2 ft |
Flood categories and crest history from the NOAA National Water Prediction Service, gauge BABM2. Stages are gage height, not depth. Not for navigation.
Nearby river gauges
- Winters Run near Bel Air, MD
- Winters Run near Benson, MD
- Plumtree Run near Bel Air, MD
- Wheel Creek near Abingdon, MD
- Bynum Run near Abingdon, MD
- James Run near Belcamp, MD
- Little Gunpowder Falls at Laurel Brook, MD
- Deer Creek at Rocks, MD
- Foster Branch near Joppatowne, MD
- Deer Creek near Darlington, MD
- Long Green Creek at Glen Arm, MD
- Deer Creek at Eden Mill Dam near Pylesville, MD
Live streamflow and gage height: USGS gauge 01581500. Percentile context computed against the gauge's period of record. Not for navigation.
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