Potomac River at Little Falls, MD
USGS gauge 01646500 · drainage 11,560 sq mi · observed Oct 16, 9:50 PM EDT · 30 min old
Weather alerts Official NWS
No active National Weather Service alerts were returned for this location. This is not a statement that conditions are safe.
Source: National Weather Service alerts for the gauge location, fetched Oct 16, 10:16 PM EDT.
Last 7 days Live gauge
Source: USGS Water Data API (continuous values), observed to Oct 16, 9:50 PM EDT. Shaded band: 25th to 75th percentile of USGS daily statistics for each date; dashed: median. Flow in cfs.
Gage height and flood stages Live gauge
| Measure | Gage height | Note |
|---|---|---|
| Latest gage height | 3.94 ft | Oct 16, 9:50 PM EDT |
| Action stage | 5.0 ft | 1.1 ft above the latest gage height |
| Minor stage | 10.0 ft | 6.1 ft above the latest gage height |
| Moderate stage | 12.0 ft | 8.1 ft above the latest gage height |
| Major stage | 14.0 ft | 10.1 ft above the latest gage height |
| Forecast high | 3.9 ft | Oct 17, 2:00 AM EDT |
Source: USGS Water Data API (continuous gage height), observed to Oct 16, 9:50 PM EDT. Flood stages and the forecast (dashed curve) from National Weather Service forecast point BRKM2, forecast issued Oct 16, 9:52 AM EDT. Dashed horizontal lines are drawn only where they fall inside the axis; all stages are in the table.
Gauge location Mapped layer
Source: Map services and data available from U.S. Geological Survey, National Geospatial Program (USGS Topo). Map about 10 miles across, centred on the gauge at 38.9498, -77.1276.
Radar Official NWS
Source: National Weather Service radar, station KLWX. The loop is served live by the NWS and shows its own frame times.
Weather forecast Official NWS
Source: National Weather Service point forecast, updated Oct 16, 7:53 PM EDT.
Public land at this gauge Mapped layer
| Unit | Managed by | Public access |
|---|---|---|
| Chesapeake and Ohio Canal National Historical Park | National Park Service | Restricted access |
| George Washington Memorial Parkway | National Park Service | Restricted access |
| Sangamore Local Park | Regional or county agency | Open access |
Source: USGS Protected Areas Database (PAD-US), within about half a mile of the gauge, downloaded 2026-10-12. Mapped land is not proof of legal access.
About USGS gauge 01646500 Historical record
| Item | Value |
|---|---|
| USGS site name | POTOMAC RIVER NEAR WASH, DC LITTLE FALLS PUMP STA |
| Site type | Stream |
| Agency | U.S. Geological Survey |
| County and state | Montgomery County, Maryland |
| Drainage area | 11,560 sq mi |
| Altitude | 37 ft (NAVD88) |
| Hydrologic unit code | 020700081005 |
| Coordinates | 38.9498, -77.1276 |
| Daily mean flow record | Mar 1, 1930 to Oct 14, 2026 |
| Instantaneous flow record | Jun 9, 1972 to Oct 16, 2026 |
| Instantaneous gage height record | Oct 1, 2007 to Oct 16, 2026 |
| Annual peaks on file | 95, 1931 to 2025 |
Source: USGS Water Data API monitoring-locations and time-series-metadata, fetched Oct 16, 10:12 PM EDT.
Sources and method
- Forecasts, alerts and observations: National Weather Service. NWS material is not subject to copyright. Terms
- Data: U.S. Geological Survey. Terms
- Map services and data available from U.S. Geological Survey, National Geospatial Program. Terms
- Rain estimates and radar: NOAA and National Weather Service. Terms
- Public land: USGS Protected Areas Database of the United States. Terms
USGS daily statistics, downloaded 2026-10-12
Percentile method: trailing 24 h mean vs USGS daily percentiles for calendar date 10-16.
Percentile is estimated from USGS published daily percentiles. Readings are provisional until USGS reviews them. Not endorsed by USGS, NOAA or the National Weather Service. Not for navigation or safety-of-life decisions; the absence of an alert is not a statement that conditions are safe.