Fair Lakes Dam #1 dam
Fair Lakes Dam #1
Fair Lakes Dam #1, also known as Seven Fair Lakes Dam, is a privately owned structure located in Fairfax, Virginia. This earthen dam stands at a height of 25 feet and stretches 980 feet in length, serving the primary purpose of flood risk reduction along the Big Rocky Run tributary. With a storage capacity of 99.43 acre-feet and a surface area of 3.81 acres, this dam plays a crucial role in managing water resources in the area.
Managed by the Department of Conservation and Recreation in Virginia, Fair Lakes Dam #1 has a high hazard potential but is currently assessed to be in satisfactory condition. Regular inspections take place to ensure its operational integrity, with the last assessment conducted in February 2020. Despite its critical role in flood risk reduction, there is limited information on its construction date or any modifications over the years, highlighting the importance of continued monitoring and maintenance to safeguard against potential risks and ensure its efficacy in the face of changing climate dynamics.
With the dam's location in a densely populated area and its vital function in mitigating flood risks, Fair Lakes Dam #1 serves as a key infrastructure for water resource and climate enthusiasts to study and monitor. As climate change impacts become more pronounced, understanding and maintaining such structures will be crucial in safeguarding communities and ecosystems from the escalating threats of extreme weather events and water resource management challenges.
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 Fair Lakes Dam #1 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Long Branch Near Annandale | 1 cfs | → |
| Accotink Creek Near Annandale | 3 cfs | → |
| Difficult Run Near Great Falls | 11 cfs | → |
| Broad Run Near Leesburg | 18 cfs | → |
| Potomac River Near Wash | 2,160 cfs | → |
| Cameron Run At Alexandria | 6 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Fair Lakes Dam #1.
Boat launches
- Sinclair Lane Prince William County
- Potomac Hills Street Fairfax County
- Forest Hill Road Lake Ridge
- Doves Trail Prince William County
- Ashburn Village Boulevard 20585, Lansdowne
- Rileys Lock Road Darnestown
Campgrounds
- Bull Run Regional Park
- Lake Fairfax
- Burke Lake Park
- Marsden Tract Group Campsite
- Marsden Tract Campground
- Outpost 60 Campsite
Fishing spots
- Gillam Branch (Historical)
- Davis Branch (Historical)
- Washington Aqueduct
- Dalecarlia Reservoir
- Maddox Branch
- Georgetown Reservoir
Paddle runs
- Bixler Bridge On State Route 675 To Karo Landing, Approximately 6 Miles South Of Town Of Front Royal
- Segment C--Nf Boundary To Confluence With North Fork Shenandoah River
- Segment B--State Route 730 Bridge To Nf Boundary
- State Route 675 At Edinburg, Va To State Highway 55 Southeast Of Strasburg, Va
- Headwaters Adjacent To Fdt 573 To State Route 622 Bridge
Track Fair Lakes Dam #1 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 Fair Lakes Dam #1
Where does the data for Fair Lakes Dam #1 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 High 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 Fair Lakes Dam #1.