West Fork Bitterroot (Painted Rocks) dam
West Fork Bitterroot (Painted Rocks)
West Fork Bitterroot (Painted Rocks) is a state-owned dam located in Ravalli, Montana, along the West Fork of the Bitterroot River. Completed in 1940, this earth dam stands at a height of 143 feet and serves primarily for irrigation purposes, with a storage capacity of 45,100 acre-feet. Despite its age, the dam has a high hazard potential and is currently rated as in poor condition, requiring regular inspections and maintenance to ensure its safety and functionality.
The dam's spillway, with a width of 160 feet, is uncontrolled, and it has a maximum discharge capacity of 3,300 cubic feet per second. The surrounding area covers 655 acres, with a drainage area of 316 square miles. The dam's reservoir has a normal storage capacity of 31,706 acre-feet, providing vital water resources for agricultural irrigation in the region. The dam is under the regulatory oversight of the Montana Department of Natural Resources and Conservation (DNRC), with state permitting, inspection, and enforcement in place to ensure compliance with safety standards.
With its historical significance and critical role in water resource management for irrigation, West Fork Bitterroot (Painted Rocks) serves as a key infrastructure in the region. As climate change impacts water availability and quality, the maintenance and upkeep of this dam become increasingly important to ensure the sustainable use of water resources for agriculture and other essential purposes. Ongoing risk assessments and management measures are necessary to address the dam's high hazard potential and poor condition, highlighting the importance of proactive measures to safeguard this vital piece of infrastructure for the future.
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 West Fork Bitterroot (Painted Rocks) -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| West Fork Bitterroot River Nr Conner Mt | 782 cfs | → |
| Bitterroot River Near Darby Mt | 3,250 cfs | → |
| Salmon River Nr Shoup Id | 5,140 cfs | → |
| Middle Fork Salmon River At Mouth Nr Shoup Id | 8,250 cfs | → |
| Napias Creek Below Arnett Creek Near Leesburg | 74 cfs | → |
| Big Hole River Bl Big Lake Cr At Wisdom Mt | 43 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near West Fork Bitterroot (Painted Rocks).
Boat launches
- West Fork Boating Site
- Applebury Boating Site
- Rocky Mountain Road Ravalli County
- Darby Boat Ramp
- Salmon River Road Lemhi County
- Lake Como Road Ravalli County
Campgrounds
Fishing spots
Paddle runs
- Nez Perce Fork Bitterroot River, Sec. 26, T1s, R22w To Painted Rocks Dam, Sec. 26, T1s, R22w
- Paradise To Selway Falls
- Lick Creek Bridge, Sec. 18, T4n, R21w To Bear Creek Pass, Sec. 5, T4n, R23w And Twin Lakes Dam, Sec. 29, T5n, R23w
- Nf Boundary At 4th Of July Creek To Confluence With North Fork
- Headwaters To Confluence With Salmon River
- Sec. 28, T30n, R13e To Boundary Selway-Bitterroot Wilderness
Track West Fork Bitterroot (Painted Rocks) 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 West Fork Bitterroot (Painted Rocks)
Where does the data for West Fork Bitterroot (Painted Rocks) 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 West Fork Bitterroot (Painted Rocks).