Johnston dam
Johnston
Johnston is a privately owned dam located in Allegheny Township, Butler County, Pennsylvania. Built in 1978, this Earth dam stands at 26 feet tall and spans a length of 925 feet, containing a storage capacity of 281 acre-feet of water for recreational purposes. Situated on TR Carrs Run, a small stream with a drainage area of 0.42 square miles, Johnston provides a surface area of 20 acres for recreational activities.
Managed by the Pennsylvania Department of Environmental Protection, Johnston is regulated, permitted, inspected, and enforced by the state to ensure its safety and compliance with regulations. With a low hazard potential and a condition assessment that is not rated, this dam serves as a recreational resource for the local community. Despite not having an Emergency Action Plan (EAP) in place currently, Johnston maintains a relatively low risk profile, emphasizing the importance of ongoing monitoring and maintenance to ensure the safety of its surrounding area.
Overall, Johnston in Butler County, Pennsylvania, is a modest-sized dam that offers recreational opportunities while also being subject to state regulations and inspections. With a focus on public safety and risk management, the dam continues to provide valuable recreational amenities to the local community while emphasizing the need for ongoing monitoring and maintenance to ensure its continued safe operation.
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 Johnston -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Allegheny River At Parker | 12,700 cfs | → |
| Allegheny River At Franklin | 10,200 cfs | → |
| Clarion River Near Piney | 1,330 cfs | → |
| French Creek At Utica | 1,670 cfs | → |
| Redbank Creek At St. Charles | 530 cfs | → |
| Muddy Creek Near Portersville | 69 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Johnston.
Boat launches
- Pa 38;Pa 208 Scrubgrass Township
- Parker City
- Kahle Lake -Clarion Access
- Kahle Lake -Venango Access
- Heck Dr 102, Armstrong County
- Main Street 215, Rockland Township
Campgrounds
- Copperhead Retreat
- Danner Campground
- Kamp Kennerdell
- Seneca Hills Bible Camp & Retreat Center
- Burnt Ridge Campground
- Two Mile Run County Park
Paddle runs
Track Johnston 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 Johnston
Where does the data for Johnston 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.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Johnston.