Boulder Lake dam
Boulder Lake
Boulder Lake, located in Valley County, Idaho, is a privately owned reservoir with a primary purpose of irrigation. The dam, a masonry structure with a multi-arch core, stands at a height of 15 feet and was completed in 1902. With a storage capacity of 1310 acre-feet and a surface area of 114 acres, Boulder Lake serves as a vital resource for the surrounding agricultural community.
The reservoir is fed by Boulder Creek, a tributary of the North Fork Payette River, and has a drainage area of 1.8 square miles. The spillway, which is uncontrolled and 480 feet wide, allows for a maximum discharge of 160 cubic feet per second. The dam's condition was last assessed as "fair" in July 2018, with a significant hazard potential and a moderate risk assessment score of 3. Despite its age, Boulder Lake continues to play a crucial role in water resource management and agricultural irrigation in the region.
Water resource and climate enthusiasts interested in the history and engineering of irrigation infrastructure will find Boulder Lake to be a fascinating case study. From its construction over a century ago to its continued operation and maintenance today, the reservoir exemplifies the intersection of human ingenuity and natural resource management. With its location in the scenic town of McCall, Idaho, Boulder Lake is not just a functional reservoir but also a reminder of the importance of sustainable water utilization in a changing climate.
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 Boulder Lake -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Lake Fork Payette River Ab Jumbo Cr Nr Mccall Id | 529 cfs | → |
| Nf Payette River At Mccall Id | 825 cfs | → |
| Sf Salmon River Nr Krassel Ranger Station Id | 1,330 cfs | → |
| Johnson Creek At Yellow Pine Id | 1,380 cfs | → |
| Sugar Creek Nr Stibnite | 45 cfs | → |
| Efsf Salmon R Abv Sugar Crk Nr Stibnite | 132 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Boulder Lake.
Boat launches
- Warren Wagon Road Mccall
- Valley County
- Fisher Creek Road Adams County
- Granite Lake Dam Road Valley County
- Grouse Creek Campground Road Adams County
- National Forest Development Road 422 Valley County
Campgrounds
- Lake Fork Campground
- Rapid Creek Dispersed Camping Area
- Paddy Flat Dispersed Camping Area
- Paddy Flat Guard Station Rental Cabin
- Kennally Creek
- Kennally Creek Campground
Paddle runs
- Secesh To Main (The Canyon)
- Ponderosa Campground To Confluence With South Fork Salmon River
- Chinook Campground To Ponderosa Campground
- Junction Fr 447 To Confluence With Johnson Creek
- Confluence With Bear Creek To Confluence With Hanson Creek
- Payette Nf Boundary On Lake Creek (Just West Marshall Lake) To To And Including Chinook Campground
More reservoirs
Track Boulder Lake 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 Boulder Lake
Where does the data for Boulder Lake 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 Significant 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 Boulder Lake.