Mosquito Flat dam
Mosquito Flat
Mosquito Flat, located in Challis, Idaho, is a privately owned water resource site regulated by the Idaho Department of Water Resources. Constructed in 1950 by the State of Idaho in collaboration with USDA NRCS, this earth dam stands at a height of 58.4 feet and serves a primary purpose of "Other." It holds a storage capacity of 793 acre-feet, with a spillway width of 15 feet and a maximum discharge of 4360 cubic feet per second.
With a significant hazard potential and fair condition assessment as of August 2017, Mosquito Flat is closely monitored through inspections every four years. The dam's hydraulic height of 49.4 feet and stone core types contribute to its structural integrity. The site's risk assessment is moderate, indicating the need for ongoing risk management measures to ensure the safety of the surrounding areas, including Custer County, Idaho, and the Salmon River.
Despite its uncontrolled spillway type and slide outlet gates, Mosquito Flat remains a vital water management structure in the region, with a drainage area of 16.1 square miles and a surface area of 46 acres. Its location along Challis Creek and the Salmon River underscores its importance in managing water resources and mitigating potential flood risks in the area. Enthusiasts of water resources and climate management will find Mosquito Flat to be a fascinating example of collaborative efforts in water infrastructure development and regulation.
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 Mosquito Flat -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Squaw Creek Bl Bruno Creek Nr Clayton Id | 91 cfs | → |
| Thompson Creek Nr Clayton Id | 44 cfs | → |
| Pahsimeroi River At Ellis Id | 235 cfs | → |
| Yankee Fork Salmon River Nr Clayton Id | 712 cfs | → |
| Salmon River Bl Yankee Fork Nr Clayton Id | 2,470 cfs | → |
| Mf Salmon River At Mf Lodge Nr Yellow Pine Id | 4,440 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Mosquito Flat.
Boat launches
- Challis Bridge Recreation Site
- Corrigan Ln Custer County
- Dugway Dispersed Site
- Old Road Custer County
- Id 75 Custer County
- Us 93 North Challis
Campgrounds
- Mosquito Flat Reservoir Campground
- Mosquito Flat Reservoir
- Twin Peaks Camping Area
- Bayhorse Campground
- Big Bayhorse
- Big Bayhorse Campground
Fishing spots
Paddle runs
- Headwaters To Nf Boundary
- Bayhorse Creek
- Challis Bridge To Deer Gulch
- West Fork Morgan Creek
- Squaw Creek
- Thompson Creek
More reservoirs
Track Mosquito Flat 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 Mosquito Flat
Where does the data for Mosquito Flat 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 Mosquito Flat.