Dam Report

Rocky Pen Run #4a dam

Virginia, USA Rocky Pen Run Hazard Low
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Tonight low
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Dam height
27ft
Hazard rating
Low
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Rocky Pen Run #4a -- None dam
Rocky Pen Run #4a None · Rocky Pen Run
About this dam

Rocky Pen Run #4a

Rocky Pen Run #4a is a state-regulated dam located in Stafford, Virginia, along the Rocky Pen Run river. The dam serves the primary purpose of flood risk reduction and water supply, standing at a height of 27 feet and with a storage capacity of 128 acre-feet. Despite its low hazard potential, the dam has a satisfactory condition assessment as of the last inspection in September 2019.

Managed by the Department of Conservation and Recreation, this earth dam has a structural length of 220 feet and covers a drainage area of 0.61 square miles. With a normal storage capacity of 34.87 acre-feet and a surface area of 7.32 acres, Rocky Pen Run #4a plays a crucial role in mitigating flood risks in the region. The dam has not undergone any modifications in recent years and meets state regulatory standards for inspection, enforcement, and permitting.

For water resource and climate enthusiasts, Rocky Pen Run #4a offers a fascinating case study in dam infrastructure management and its impact on local water systems. With its dual purpose of flood risk reduction and water supply, this dam is a vital component of the region's water management strategy. As climate change continues to pose challenges to water resources, understanding the role of structures like Rocky Pen Run #4a becomes increasingly important in ensuring the resilience of communities and ecosystems in the face of changing environmental conditions.

StateNone
River / streamRocky Pen Run
NID IDVA179013
Owner typeNot Listed
Primary purposeFlood Risk Reduction
Dam height27 ft
Dam length220 ft
Max storage128 AF
Normal storage35 AF
Surface area7.3 ac
Drainage area0.6 sq mi
Hazard potentialLow
ConditionSatisfactory
Last inspectionFri, 20 Sep 2019 00:00:00 GMT

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.
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 Rocky Pen Run #4a -- inflows here typically show up in storage 24-72 hours later.

Track Rocky Pen Run #4a 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.

FAQ

About Rocky Pen Run #4a

Where does the data for Rocky Pen Run #4a 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.

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