Lower Peak Lake Auxiliary dam
Lower Peak Lake Auxiliary
Lower Peak Lake Auxiliary is a private hydroelectric dam located in Placer County, California, near the town of Washington. Built in 1860, this earth dam stands at a height of 7 feet and has a hydraulic height of 3.5 feet. With a storage capacity of 484 acre-feet, the dam serves the primary purpose of hydroelectric power generation and is regulated by the Federal Energy Regulatory Commission.
Situated on the South Yuba River, Lower Peak Lake Auxiliary has a surface area of 33.3 acres and a maximum discharge of 312 cubic feet per second. The dam features an uncontrolled spillway with a width of 55 feet and has a low hazard potential. Although the condition assessment is not available, the risk assessment is moderate, with a risk level of 3. Emergency action plans have been prepared and last revised in December 2020, ensuring that the dam is well-prepared for any potential hazards.
Overall, Lower Peak Lake Auxiliary is a historic structure with a vital role in providing hydroelectric power to the region. Its location in the picturesque surroundings of Placer County makes it a significant landmark for water resource and climate enthusiasts interested in the sustainable development of water infrastructure in California.
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 Lower Peak Lake Auxiliary -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Donner C A Donner Lk Nr Truckee Ca | 9 cfs | → |
| Donner C At Hwy 89 Nr Truckee Ca | 53 cfs | → |
| Truckee R Nr Truckee Ca | 438 cfs | → |
| Independence C Nr Truckee Ca | 19 cfs | → |
| Sagehen C Nr Truckee Ca | 9 cfs | → |
| Little Truckee R Bl Div Dam Nr Sierraville Ca | 3 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lower Peak Lake Auxiliary .
Boat launches
- Lake Spaulding Road 10260, Nevada City
- Fuller Lake Boating Site
- Meadow Lake Road Nevada County
- Mosquito Ridge Rd, California
- Woodcamp Access Road Nevada County
- Henness Pass Road, Sierraville
Campgrounds
- Muninnvagl
- Cold Springs Campground
- Hampshire Rocks
- Hampshire Rocks Campground
- Loch Leven Lakes Dispersed Camping
- Big Bend Group Campground
Fishing spots
Paddle runs
- Royal Gorge (Soda Springs To Tadpole Creek)
- Generation And Giant Gaps (Tadpole To Colfax-Iowa Hill Road)
- Langs Crossing Bridge To One-Half Mile West Of Confluence With Fall Creek (Boundary Of Nf And Private Land)
- Hell Hole Dam To Ellicotts Bridge
- Headwaters Se 1/4 Of Sec 10, T18, R15e To Stampede Reservoir
- Tahoe City To River Ranch
Track Lower Peak 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 Lower Peak Lake Auxiliary
Where does the data for Lower Peak 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 Low 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 Lower Peak Lake Auxiliary .