Lake Spaulding No. 3 Auxiliary Dam
Lake Spaulding No. 3 Auxiliary
Lake Spaulding No. 3 Auxiliary is a concrete gravity dam located in Nevada County, California, near the city of Washington. Built in 1919, this hydroelectric structure stands at 91 feet tall and has a capacity of 74,773 acre-feet, serving as a vital component of the South Yuba River's water resource management system. Managed by a private entity, this dam is regulated and inspected by the California Department of Water Resources for safety compliance.
The dam's spillway type is uncontrolled, with a width of 90 feet, and it has a high hazard potential due to its location and structural components. The dam's emergency action plan was last revised in December 2020, ensuring that proper guidelines are in place for potential risks. Lake Spaulding No. 3 Auxiliary has a moderate risk assessment rating, indicating the need for ongoing monitoring and risk management measures to maintain public safety and environmental integrity in the face of changing climate patterns and water resource demands.
As a crucial part of the Federal Energy Regulatory Commission's oversight, this dam plays a significant role in supporting hydroelectric power generation and water supply for the surrounding area. With its historical significance and engineering ingenuity, Lake Spaulding No. 3 Auxiliary stands as a testament to the enduring importance of sustainable water resource management in the face of evolving climate challenges.
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 Lake Spaulding No. 3 Auxiliary -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Little Truckee R Bl Div Dam Nr Sierraville Ca | 3 cfs | → |
| N Yuba R Bl Goodyears Bar Ca | 170 cfs | → |
| Independence C Nr Truckee Ca | 6 cfs | → |
| Donner C A Donner Lk Nr Truckee Ca | 4 cfs | → |
| Sagehen C Nr Truckee Ca | 2 cfs | → |
| Donner C At Hwy 89 Nr Truckee Ca | 7 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lake Spaulding No. 3 Auxiliary .
Boat launches
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Campgrounds
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Fishing spots
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River runs
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About Lake Spaulding No. 3 Auxiliary
Where does the data for Lake Spaulding No. 3 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 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 below 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.
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.