Long Branch Near Annandale flow report
As of July 13, 2026, Long Branch Near Annandale is flowing at 1 cfs with a gage height of 2.52 ft, receding 26% over the past 24 hours. Source: USGS gauge #01654500, refreshed throughout the day.
Historical Data
Long Branch Near Annandale at a glance
How Long Branch Near Annandale is running right now, where it sits on the map, and the key gauge stats.
Long Branch Near Annandale is flowing at 1 cfs, with the water sitting 2.52 ft at the gage. Flow is down 26% since yesterday as the gauge recedes.
This is USGS gauge #01654500 in Virginia. Over the past 10 days the average has been 3 cfs, peaking at 15 cfs.
Over the next 5 days, Long Branch Near Annandale is expected to recede from today's 1 cfs, toward roughly 1 cfs by 2026-07-17 (likely range 0-4 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 Virginia 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.
Long Branch Near Annandale
The stream receives water from various sources, including stormwater runoff, groundwater discharge, and precipitation. It is not impacted by any dams, but there are several smaller tributaries that contribute to its flow. Seasonal trends show higher flow during the spring and fall, and lower flow during the summer and winter. Interesting facts about Long Branch include its historical use as a source of water for agriculture and its current designation as impaired due to high levels of bacteria. Overall, understanding Long Branch's hydrology is important for managing its water quality and protecting the health of the Potomac River watershed.
Nearby streamflow levels
Cross-check Long Branch Near Annandale's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Long Branch Near Annandale | 1 cfs |
| Accotink Creek Near Annandale | 14 cfs |
| Cameron Run At Alexandria | 10 cfs |
| Fourmile Run At Alexandria | 5 cfs |
| Potomac River Near Wash | 5,290 cfs |
| Difficult Run Near Great Falls | 23 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Long Branch Near Annandale. 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 |
|---|---|
| Vienna Coop | 0 in |
| Dalecarlia Reservoir Coop | 0 in |
| Wfo Sterling Coop | 0 in |
| Montgomery Village 1.1 Ene | 0 in |
| Ashton-Sandy Spring 1.8 Nnw | 0 in |
| Damascus 3 Ssw Coop | 0 in |
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 Long Branch Near Annandale in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Long Branch Near Annandale crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Long Branch Near Annandale
Where does the streamflow data for Long Branch Near Annandale come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 01654500. 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 Long Branch Near Annandale 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 Long Branch Near Annandale report
Create your free account to track this river — and everything else you love on the water.
- Flow alerts — get pinged the moment this river hits your range
- Save favorites — every river, lake & snowpack in one place
- Full history & forecasts — plus the free iPhone app