Loyalhanna Dam dam
Loyalhanna Dam
Loyalhanna Dam, also known as Loyalhanna Lake, is a gravity dam located in Westmoreland, Pennsylvania, along the Loyalhanna Creek. Built in 1942 by the US Army Corps of Engineers, the primary purpose of this dam is flood risk reduction, with additional purposes including recreation. The dam stands at a structural height of 120 feet, with a hydraulic height of 114 feet, and a length of 960 feet. It has a maximum storage capacity of 127,556 acre-feet and a normal storage capacity of 2,000 acre-feet.
The dam is equipped with a controlled spillway and a variety of outlet gates to manage water levels. It has a high hazard potential and is subject to regular inspections and risk management measures. The US Army Corps of Engineers works diligently to monitor the dam's condition, prioritize risk-reducing activities, and collaborate with local emergency managers and the public to ensure preparedness in case of a dam-related emergency. Despite its flood risk reduction capabilities, the dam cannot eliminate all risks of flooding, especially during severe weather events that may overwhelm its capacity.
In summary, Loyalhanna Dam serves as a critical infrastructure for flood risk reduction in the region. With a focus on safety and risk management, the US Army Corps of Engineers implements measures to ensure the dam's structural integrity and collaborates with local stakeholders to enhance emergency preparedness. As a key component of water resource management, Loyalhanna Dam plays a vital role in protecting communities downstream from potential flooding events.
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 Loyalhanna Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Loyalhanna Creek At Loyalhanna Dam | 221 cfs | → |
| Conemaugh River At Tunnelton | 1,220 cfs | → |
| Kiskiminetas River At Vandergrift | 1,610 cfs | → |
| Loyalhanna Creek At Kingston | 203 cfs | → |
| Blacklick Creek At Josephine | 173 cfs | → |
| Crooked Creek At Idaho | 66 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Loyalhanna Dam.
Boat launches
- Tailwater
- Christopher's Road
- Alexandria Launch
- Salem Access
- Bow Ridge (Ada Use Only)
- Keystone State Park Lake
Campgrounds
- Bush
- Keystone State Park
- Crooked Creek Recreation Area
- Camp Ligonier
- Antiochian Village Camp
- Cedar Creek Trekker Campground
Paddle runs
- Begins Below The Youghiogheny River Lake Dam In Confluence, Pennsylvania To Ends In South Connellsville, Pennsylvania
- Howe Bridge (Tr 342), Clarion County To Confluence With Piney Reservoir
More reservoirs
Track Loyalhanna 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 Loyalhanna Dam
Where does the data for Loyalhanna 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 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 Loyalhanna Dam.