About this river
Potomac River is a 7.5 mile river near Calleva's River School in Maryland. Streamflow is measured at the USGS gauge Potomac River at Point of Rocks, MD (site 01638500). The National Hydrography Dataset places it at stream order 8. Reach geometry comes from the USGS National Hydrography Dataset.
Typical flow by month
1895 to 2026
Potomac River typically runs highest in March, at a median 13,700 cfs, and lowest in September, at 2,180 cfs. The highest flow on record for any single day is 434,000 cfs, in 1936.
| Month | Typical (cfs) | Usual range (cfs) | Relative level |
|---|---|---|---|
| January | 7,710 | 4,600 to 13,500 | |
| February | 9,250 | 5,880 to 16,500 | |
| March | 13,700 | 8,690 to 22,100 | |
| April | 11,850 | 7,630 to 18,700 | |
| May | 8,690 | 5,550 to 14,900 | |
| June | 5,075 | 3,515 to 8,215 | |
| July | 3,210 | 2,460 to 5,030 | |
| August | 2,740 | 1,850 to 4,050 | |
| September | 2,180 | 1,530 to 3,605 | |
| October | 2,260 | 1,560 to 4,200 | |
| November | 3,030 | 1,990 to 6,060 | |
| December | 5,850 | 3,090 to 10,300 |
Typical is the median of each month’s daily median values, and the usual range runs from the median 25th to the median 75th percentile, across about 132 years of record. Statistics published by the US Geological Survey for Potomac River at Point of Rocks, MD (site 01638500). Conditions on any given day can fall well outside the usual range. Check the current reading before you go.
Embed this gauge on your site
Paste this snippet anywhere, an outfitter page, a club site, a trip report, to show Potomac River's live streamflow, water level and 7-day trend. It reads the USGS gauge directly, updates itself, and links back here.
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