Dam Report

Gathright Dam dam

Virginia, USA Jackson River Hazard High
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Dam height
257ft
Hazard rating
High
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Gathright Dam -- Virginia dam
Gathright Dam Virginia · Jackson River
About this dam

Gathright Dam

Gathright Dam, also known as Lake Moomaw, is a rockfill dam located on the Jackson River in Alleghany, Virginia. Completed in 1978 by the US Army Corps of Engineers, the dam stands at a height of 257 feet and has a maximum storage capacity of 421,500 acre-feet. The primary purpose of Gathright Dam is flood risk reduction, with additional benefits for fish and wildlife, recreation, and water supply.

USACE has identified Gathright Dam as having a high hazard potential, with a moderate risk assessment rating. The dam poses a risk of catastrophic flooding downstream if uncontrolled releases were to occur, impacting communities along the Jackson and James Rivers. To manage and reduce this risk, USACE conducts regular inspections, maintains the structure, and collaborates with local emergency managers for emergency preparedness. Additionally, mitigation measures were implemented during construction to address potential risks to the dam's integrity, such as water seepage and earth material slides.

Overall, Gathright Dam serves as a critical infrastructure for flood control in the region, with USACE actively working to ensure its safety and reliability through risk management measures and ongoing maintenance activities. As a key component of water resource management in Virginia, the dam plays a crucial role in safeguarding downstream communities from the impacts of potential flood events.

StateVirginia
River / streamJackson River
NID IDVA005001
Owner typeFederal
Primary purposeFlood Risk Reduction
Dam typeRockfill
Year built1978
Dam height257 ft
Dam length1,208 ft
Max storage421,500 AF
Normal storage123,700 AF
Surface area2,530.0 ac
Drainage area345.0 sq mi
Hazard potentialHigh
ConditionNot Available
Last inspectionFri, 03 May 2019 00:00:00 GMT
EAP preparedYes
Detailed forecast

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.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

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.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

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Regional inflow

Nearby streamflow gauges

USGS streamgauges around Gathright Dam -- inflows here typically show up in storage 24-72 hours later.

Around the water

Make a day of it

Boat launches, lakeside camping, fishing access, and other reservoirs near Gathright Dam.

FAQ

About Gathright Dam

Where does the data for Gathright 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 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 below 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.

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.