Lower Theisman Dam dam
Lower Theisman Dam
Lower Theisman Dam, located in Loudoun, Virginia, is a privately owned earth dam with a primary purpose of recreation. Standing at a height of 20 feet and stretching 660 feet in length, this dam creates a storage capacity of 92.3 acre-feet, providing a serene surface area of 7 acres for visitors to enjoy. Situated on the Limestone Branch tributary, the dam is regulated, permitted, inspected, and enforced by the Department of Conservation and Recreation in Virginia.
Although the dam's hazard potential is currently classified as undetermined and its condition is not rated, Lower Theisman Dam serves as a vital recreational resource for the community. With its picturesque surroundings and ample storage capacity, the dam offers opportunities for outdoor activities and water-based recreation. As water resource and climate enthusiasts, the presence of this dam underscores the importance of sustainable water management practices and the need to balance recreational benefits with dam safety considerations.
As Lower Theisman Dam continues to provide recreational opportunities for visitors, there is a growing emphasis on ensuring its long-term safety and functionality. With the support of regulatory agencies and ongoing inspections, efforts are being made to maintain the dam's integrity and mitigate potential risks. By staying informed and engaged in the management of this essential water resource, enthusiasts can contribute to the preservation of both natural ecosystems and recreational amenities for future generations.
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 Lower Theisman Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Limestone Branch Near Leesburg | 2 cfs | → |
| S F Catoctin Creek At Rt 698 Near Waterford | 4 cfs | → |
| Catoctin Creek At Taylorstown | 17 cfs | → |
| N F Catoctin Creek At Rt 681 Near Waterford | 4 cfs | → |
| Potomac River At Point Of Rocks | 2,470 cfs | → |
| Bennett Creek At Park Mills | 17 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lower Theisman Dam.
Boat launches
- Smart's Mill Rd (Private) Leesburg
- Chesapeake And Ohio Canal Trail Point Of Rocks
- Chesapeake And Ohio Canal Frederick County
- Chesapeake And Ohio Canal Trail Frederick County
- Edwards Ferry Road Montgomery County
- South Maple Avenue 105, Brunswick
Campgrounds
- Marble Quarry Hiker-Biker Campsite
- Marble Quarry
- Turtle Run
- Turtle Run Campsite
- Calico Rocks
- Calico Rocks Campsite
Fishing spots
- Culler Lake
- Potomac River Reservoir
- Chesapeake And Ohio Canal
- Hunting Creek Lake
- Washington Aqueduct
- Dalecarlia Reservoir
Paddle runs
- Headwaters Adjacent To Fdt 573 To State Route 622 Bridge
- Bixler Bridge On State Route 675 To Karo Landing, Approximately 6 Miles South Of Town Of Front Royal
- State Route 675 At Edinburg, Va To State Highway 55 Southeast Of Strasburg, Va
- Segment C--Nf Boundary To Confluence With North Fork Shenandoah River
- Segment B--State Route 730 Bridge To Nf Boundary
- Capon Bridge To Ends Just South Of Largent
Track Lower Theisman Dam 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 Lower Theisman Dam
Where does the data for Lower Theisman Dam 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 Undetermined 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 Lower Theisman Dam.