Potomac River Near Wash flow report
As of July 13, 2026, Potomac River Near Wash is flowing at 5,290 cfs with a gage height of 3.40 ft, rising 8% over the past 24 hours. Source: USGS gauge #01646500, refreshed throughout the day.
Historical Data
Potomac River Near Wash at a glance
How Potomac River Near Wash is running right now, where it sits on the map, and the key gauge stats.
Potomac River Near Wash is flowing at 5,290 cfs, with the water sitting 3.40 ft at the gage. Flow is up 8% since yesterday — a rising hydrograph.
This is USGS gauge #01646500 in Maryland. Over the past 10 days the average has been 3,800 cfs, peaking at 7,080 cfs.
Over the next 5 days, Potomac River Near Wash is expected to recede from today's 5290 cfs, toward roughly 4321 cfs by 2026-07-18 (likely range 2379-7851 cfs) -- drier than normal for the date.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Maryland flow report.
Streamflow Forecast
Powered by PULSE — Snoflo’s Predictive Unified Learning & Simulation Engine, which learns from how this river has answered every past storm, snowmelt, and dry spell to forecast where it’s headed with a precision generic models can’t match.
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
Potomac River Near Wash
This river is a major source of freshwater for the Chesapeake Bay and serves as a drinking water source for millions of people in the region. There are several tributaries that feed into the Potomac, including the Anacostia River, which has a history of pollution. The river's flow rate can vary greatly depending on seasonal trends, with higher flows during the spring and lower flows during the summer. The river's hydrology is also affected by several dams along its length, including the Great Falls Dam. Interestingly, the river played a significant role in the American Civil War and is home to a variety of wildlife, including bald eagles and river otters.
Nearby streamflow levels
Cross-check Potomac River Near Wash's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Potomac River Near Wash | 5,290 cfs |
| Rock Creek At Sherrill Drive Washington | 82 cfs |
| Difficult Run Near Great Falls | 23 cfs |
| Fourmile Run At Alexandria | 5 cfs |
| Nw Branch Anacostia River Near Hyattsville | 10 cfs |
| Nw Branch Anacostia River Near Colesville | 3 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Potomac River Near Wash. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| Dalecarlia Reservoir Coop | 0 in |
| Vienna Coop | 0 in |
| Ashton-Sandy Spring 1.8 Nnw | 0 in |
| Montgomery Village 1.1 Ene | 0 in |
| Wfo Sterling Coop | 0 in |
| Damascus 3 Ssw Coop | 0 in |
Plan a trip
Reservoirs, boat launches, river runs, and fishing spots within driving distance of Potomac River Near Wash.
Boat launches
See all →
River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track Potomac River Near Wash in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Potomac River Near Wash crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Potomac River Near Wash
Where does the streamflow data for Potomac River Near Wash come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 01646500. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when Potomac River Near Wash rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free Potomac River Near Wash report
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