Pa-481 dam
Pa-481
Pa-481 is a crucial earth dam located in Washington, Pennsylvania, specifically in Hanover Township along the Harmon Creek. Constructed in 1984 by the USDA NRCS, this dam serves the primary purpose of flood risk reduction, with a dam height of 51 feet and a length of 560 feet. It has a storage capacity of 1,620 acre-feet and covers a surface area of 11 acres, providing protection for a drainage area of 3.41 square miles.
Managed by the Pennsylvania Department of Environmental Protection, Pa-481 is regulated, permitted, inspected, and enforced to ensure its structural integrity and safety. Despite its high hazard potential, the dam's condition assessment remains satisfactory, with the last inspection conducted in November 2020. As a part of the flood risk management system, Pa-481 plays a vital role in protecting the surrounding community from potential flooding events, highlighting the importance of proper maintenance and monitoring of water resource infrastructure in the face of climate change challenges.
With its significant contribution to flood risk reduction and water resource management in the region, Pa-481 stands as a testament to the collaborative efforts between local government agencies, regulatory bodies, and the USDA NRCS in safeguarding communities against potential natural disasters. As water resource and climate enthusiasts, understanding the critical role of structures like Pa-481 in mitigating flood risks and ensuring public safety underscores the importance of sustainable water management practices and infrastructure investments to build resilience in the face of a changing climate.
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 Pa-481 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Kings Creek At Weirton | 18 cfs | → |
| Ohio River At Sewickley | 20,900 cfs | → |
| Raccoon Creek At Moffatts Mill | 68 cfs | → |
| Chartiers Creek At Carnegie | 143 cfs | → |
| Yellow Creek Near Hammondsville Oh | 64 cfs | → |
| Little Beaver Creek Near East Liverpool Oh | 334 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Pa-481.
Boat launches
Campgrounds
- Raccoon Creek State Park
- Montour Trail - Boggs Trailhead Campsite
- Tomlinson Run State Park
- Jefferson Lake State Park
- Beaver Creek State Park
- Harts Content Campground
Track Pa-481 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 Pa-481
Where does the data for Pa-481 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 Pa-481.