Lake Aloha Auxiliary No. 4 dam
Lake Aloha Auxiliary No. 4
Lake Aloha Auxiliary No. 4, also known as Medley Lakes Auxiliary No. 4, is a private water resource located in El Dorado County, California, near South Lake Tahoe. This hydroelectric facility, completed in 1917, serves multiple purposes including hydroelectric power generation and irrigation. The dam, a rockfill structure standing at 9 feet tall with a structural height of 8.5 feet, contributes to the storage of water in the South Fork American River watershed.
With a storage capacity of 5063 acre-feet and a surface area of 630 acres, Lake Aloha Auxiliary No. 4 plays a crucial role in water management and conservation in the region. Although classified as having a low hazard potential, its risk assessment is considered high, emphasizing the importance of regular inspections and adherence to safety protocols. Managed by the Federal Energy Regulatory Commission, this dam is subject to state regulations and inspections to ensure its integrity and safety for the surrounding community and environment.
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 Lake Aloha Auxiliary No. 4 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Upper Truckee R At Hwy 50 Above Meyers Ca | 188 cfs | → |
| Upper Truckee R At S Upper Truckee Rd Nr Meyers Ca | 4 cfs | → |
| Up Truckee R A South Lake Tahoe Ca | 195 cfs | → |
| Trout C Nr Tahoe Valley Ca | 52 cfs | → |
| Edgewood Ck At Stateline | 2 cfs | → |
| Eagle Rock Ck Nr Stateline | 1 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lake Aloha Auxiliary No. 4.
Boat launches
- Ice House Road El Dorado County
- Amador County
- Dry Lakes Trail El Dorado County
- Cave Rock Boat Launch Douglas County
- Junction Boat Ramp Road El Dorado County
- Indian Creek Camp Ground Day Use Area
Campgrounds
Fishing spots
Paddle runs
- 1/4 Mile North Of State Highway 50 To Avalanche Lake
- State Highway 50 To 1/4 Mile North Of State Highway 50
- Headwaters In Sec 7, T11n, R18e To Blair Bridge
- Headwaters To South Of Upper Truckee Road (Sec Line Between 17/20 Intercepts River And Unnamed Tributary)
- Headwaters In Sec 15,T10n, R17e To Confluence With Silver Fork Of American River
- Headwatersa In Sec 18, T9n, R16e To Confluence With Van Horn Creek
Track Lake Aloha Auxiliary No. 4 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 Lake Aloha Auxiliary No. 4
Where does the data for Lake Aloha Auxiliary No. 4 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 Lake Aloha Auxiliary No. 4.