Willow Creek dam
Willow Creek
Willow Creek, also known as Lodge Grass Reservoir, is a federal-owned irrigation structure located in Big Horn, Montana. Managed by the Bureau of Indian Affairs, this earth dam was completed in 1941 and serves the primary purpose of irrigation. With a structural height of 113 feet and a length of 2508 feet, the reservoir has a normal storage capacity of 23,000 acre-feet.
The dam's spillway type is controlled, and it has a high hazard potential, with a risk assessment rating of very high. Despite not being state-regulated, Willow Creek has undergone regular inspections, with the last one conducted in July 2012. The emergency action plan was last revised in August 2012, ensuring that necessary measures are in place to mitigate risks associated with the reservoir.
Located in a picturesque setting along Willow Creek, this irrigation structure plays a crucial role in supporting agriculture in the region. Enthusiasts interested in water resources and climate will appreciate the engineering marvel of Willow Creek and the efforts taken by the Bureau of Indian Affairs to ensure its safe operation and maintenance.
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 Willow Creek -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Little Bighorn River At State Line Nr Wyola Mt | 335 cfs | → |
| West Pass Creek Near Parkman | 10 cfs | → |
| East Pass Creek Near Dayton | 12 cfs | → |
| Bighorn River Near St. Xavier | 1,570 cfs | → |
| Tongue River Near Dayton | 48 cfs | → |
| Rosebud C At Reservation Bndry Nr Kirby Mt | 7 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Willow Creek.
Campgrounds
- Afterbay - Bighorn Canyon National Rec Area
- Afterbay Campground
- Bighorn Fas
- Tongue Canyon Campground
- Mallards Landing Fas
- Tongue River Camp - Amsden Creek Wma
Fishing spots
- Bighorn Lake
- Tongue River Fishing Site
- Tongue River Fishing East
- Tongue River Fishing West
- Big Horn Lake
- Sheridan Fairgrounds Pond
Paddle runs
- Wagon Box Creek To Dry Fork Trail
- Dry Fork River From Its Confluence With Lake Creek To Confluence With Little Big Horn
- Southeastern Boundary Of Bighorn Canyon National Recreation Area To Confluence With Bighorn River
- Fools Gold Crossing (Fdr 480) To Wagon Box Creek
- Bridge At Tongue River Canyon To Burgess Picnic Grounds
- Porcupine Creek
Track Willow Creek 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 Willow Creek
Where does the data for Willow Creek 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 Willow Creek.