Petranek Reservoir dam
Petranek Reservoir
Petranek Reservoir, located in Fergus County, Montana, is a private earth dam constructed in 1937 by the USDA NRCS for fire protection, stock, and as a small fish pond. The reservoir has a dam height of 34 feet and a storage capacity of 125 acre-feet, providing a reliable water source for agricultural and wildlife needs in the area. Situated on TR-ARMELLS CREEK, Petranek Reservoir plays a crucial role in maintaining water supply security in the region.
Despite being privately owned, Petranek Reservoir is state-regulated by the Montana Department of Natural Resources and Conservation (DNRC), ensuring that it meets necessary safety and operational standards. With a low hazard potential and a condition assessment of "Not Rated," the reservoir poses minimal risks to the surrounding community. While the dam has not been modified in recent years, regular inspections and enforcement by state agencies guarantee its structural integrity and functionality for the future.
In the event of an emergency, the reservoir is equipped with an Emergency Action Plan (EAP) to guide response efforts and ensure public safety. Although the details of the EAP and risk assessment are not currently available, Petranek Reservoir remains a vital resource for water management and climate resilience in the region, serving as a model for sustainable water infrastructure development.
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 Petranek Reservoir -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Missouri River Near Landusky Mt | 7,240 cfs | → |
| Judith River Nr Mouth | 416 cfs | → |
| Peoples Creek Near Hays Mt | 2 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Petranek Reservoir.
Boat launches
- Homestead - Gus Nelson
- Woodhawk (Lower)
- Woodhawk (Middle)
- Hideaway Recreation Area
- Woodhawk (Upper)
- James Kipp Recreation Area
Campgrounds
- Woodhawk Recreation Area
- Woodhawk (Middle)
- Hideaway Recreation Area
- Woodhawk (Upper)
- James Kipp
- James Kipp Recreation Area - Umrbnm
Track Petranek Reservoir 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 Petranek Reservoir
Where does the data for Petranek Reservoir 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 Petranek Reservoir.