Pr-40 Retention Dam dam
Pr-40 Retention Dam
Located in Hinsdale, Montana, the Pr-40 Retention Dam is a crucial water resource managed by the Bureau of Land Management. Built in 1942, this gravity dam stands at a structural height of 18 feet and has a hydraulic height of 14 feet, serving multiple purposes such as fire protection, stock, and small fish pond. With a storage capacity of 127.69 acre-feet and covering a surface area of 22.6 acres, this dam plays a vital role in managing water resources in the region.
The Pr-40 Retention Dam is situated on the Larb Creek/Milk River and has a low hazard potential. Despite not being rated for its condition, the dam underwent its last inspection in August 2016 with a scheduled inspection frequency of 5 years. While the dam does not have an emergency action plan in place, it remains under the jurisdiction of the Bureau of Land Management, ensuring continued oversight and management to mitigate any potential risks or hazards associated with the structure.
Water resource and climate enthusiasts will appreciate the historical significance and functional importance of the Pr-40 Retention Dam in sustaining water supply, protecting against wildfires, and supporting local ecosystems. As part of the larger network of water infrastructure in Montana, this dam stands as a testament to effective resource management and proactive measures taken to ensure the safety and sustainability of water resources in the region.
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 Pr-40 Retention Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Beaver Cr Bl Guston Coulee Nr Saco Mt | 67 cfs | → |
| Milk River At Juneberg Bridge Nr Saco Mt | 182 cfs | → |
| Beaver Creek Near Hinsdale Mt | 35 cfs | → |
| Milk River At Malta Mt | 56 cfs | → |
| Milk River At Tampico Mt | 52 cfs | → |
| Milk River Near Dodson Mt | 17 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Pr-40 Retention Dam.
Campgrounds
Track Pr-40 Retention 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 Pr-40 Retention Dam
Where does the data for Pr-40 Retention 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 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 Pr-40 Retention Dam.