Loon Lake Auxiliary dam
Loon Lake Auxiliary
Loon Lake Auxiliary, located in El Dorado County, California, is a rockfill dam primarily used for hydroelectric power generation and recreational purposes. Built in 1963 by Bechtel, this dam stands at a height of 90 feet and has a structural height of 102 feet. It has a storage capacity of 69,309 acre-feet, with a normal storage level of 51,000 acre-feet, covering a surface area of 1,450 acres.
Managed by the Federal Energy Regulatory Commission, the dam is inspected annually and is deemed to have a significant hazard potential. The surrounding area is at high risk, according to a risk assessment, with emergency action plans in place. While the dam has not undergone a recent condition assessment, it is regulated and permitted by the California Department of Water Resources, ensuring its safety and compliance with state standards. Overall, Loon Lake Auxiliary serves as a vital resource for water supply, electricity generation, and recreational activities 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 Loon Lake Auxiliary -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Blackwood C Nr Tahoe City Ca | 36 cfs | → |
| General C Nr Meeks Bay Ca | 7 cfs | → |
| Ward C At Hwy 89 Nr Tahoe Pines Ca | 22 cfs | → |
| Pilot C Ab Stumpy Meadows Res Ca | 3 cfs | → |
| Truckee R A Tahoe City Ca | 352 cfs | → |
| Pilot C Bl Mutton Canyon Nr Georgetown Ca | 2 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Loon Lake Auxiliary .
Boat launches
- Ice House Road El Dorado County
- Dry Lakes Trail El Dorado County
- Mosquito Ridge Rd, California
- Junction Boat Ramp Road El Dorado County
- Poho Ridge El Dorado County
- Forebay Road El Dorado County
Campgrounds
- Loon Lake Chalet
- Loon Lake Campground
- Loon Lake Group Campground
- Northshore Campground
- Red Fir Group Campground
- Northshore
Fishing spots
Track Loon Lake Auxiliary 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 Loon Lake Auxiliary
Where does the data for Loon Lake Auxiliary 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 Loon Lake Auxiliary .