Little Falls Dam - Potomac River dam
Little Falls Dam - Potomac River
Little Falls Dam on the Potomac River, also known as Potomac River Dam #1, is a gravity dam managed by the US Army Corps of Engineers in Montgomery County, Maryland. Completed in 1958, this dam primarily serves as a water supply source, with a normal storage capacity of 1008 acre-feet and a total storage capacity of 13360 acre-feet. The dam stands at a height of 12 feet and spans a length of 1300 feet, making it a vital infrastructure for regulating water flow and ensuring water availability in the region.
The dam has a low hazard potential and is not currently rated for its condition. However, it is subject to regular inspections by the Maryland Dam Safety agency, with the last inspection conducted in December 2013. Little Falls Dam plays a crucial role in managing water resources in the area, with a maximum discharge capacity of 484,000 cubic feet per second. Despite its age, the dam has undergone modifications in 1986 to enhance its hydraulic capabilities, reflecting a commitment to maintaining and improving its functionality for the future.
Located in Washington, DC, the Little Falls Dam is part of the larger water management infrastructure on the Potomac River. With its rock foundation and uncontrolled spillway, it ensures the efficient control of water flow and protects against potential flooding events. As climate change brings about increased variability in weather patterns, the significance of dams like Little Falls in ensuring water security and mitigating risks from extreme weather events becomes ever more critical.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
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. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Little Falls Dam - Potomac River -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Potomac River Near Wash | 2,450 cfs | → |
| Rock Creek At Sherrill Drive Washington | 38 cfs | → |
| Difficult Run Near Great Falls | 14 cfs | → |
| Fourmile Run At Alexandria | 3 cfs | → |
| Nw Branch Anacostia River Near Hyattsville | 10 cfs | → |
| Nw Branch Anacostia River Near Colesville | 5 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Little Falls Dam - Potomac River.
Boat launches
- Gravelly Point Boat Ramp
- Potomac Hills Street Fairfax County
- Wayne F Anderson Bikeway Alexandria
- Anacostia Park Boat Ramp
- Rileys Lock Road Darnestown
- Ludgate Drive Mount Vernon
Campgrounds
- Marsden Tract Campground
- Marsden Tract Group Campsite
- Swains Lock Hiker-Biker Campsite
- Lake Fairfax
- Camp Loop D
- Camp Loop C
Track Little Falls Dam - Potomac River in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Little Falls Dam - Potomac River
Where does the data for Little Falls Dam - Potomac River come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Low hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Little Falls Dam - Potomac River.