Cape Horn dam
Cape Horn
Cape Horn, also known as Van Arsdale, is a privately owned hydroelectric dam located in Mendocino, California, along the Eel River. Completed in 1907, this earth dam stands at a height of 60 feet and has a structural height of 63 feet, with a storage capacity of 390 acre-feet. With a maximum discharge of 115,000 cubic feet per second, Cape Horn plays a crucial role in regulating water flow and generating hydroelectric power in the region.
Managed by the Federal Energy Regulatory Commission, Cape Horn is classified as a high hazard potential dam with a moderate risk assessment rating. Despite its age, the dam is regularly inspected and maintained to ensure its structural integrity and safety. The surrounding area has a normal storage capacity of 102 acre-feet and covers a surface area of 65 acres, serving as a key resource for water supply and management in the region.
With its strategic location and significant contribution to hydroelectric power generation, Cape Horn stands as a vital infrastructure for water resource and climate enthusiasts. Its role in regulating water flow, providing storage capacity, and generating renewable energy showcases the importance of sustainable water management practices in the face of changing climate conditions.
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 Cape Horn -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Ef Russian R Nr Calpella Ca | 50 cfs | → |
| Outlet C Nr Willits Ca | 4 cfs | → |
| Ef Russian R Nr Ukiah Ca | 156 cfs | → |
| Russian R Nr Ukiah Ca | 0 cfs | → |
| Willits C Ab Lk Emily Nr Willits Ca | 0 cfs | → |
| Russian R Nr Talmage Ca | 95 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Cape Horn .
Campgrounds
- Trout Creek Campgounds
- Pine Mountain Lookout
- Fuller Grove Group Campground
- Fuller Grove Campground
- Fuller Grove - Lake Pillsbury
- Pogie Point Campground
Fishing spots
- Lake Pillsbury
- Lake Mendocino
- Cameron's Fishing Hole Catch & Release
- Clear Lake (Lake Cty)
- East Park Reservoir
- Lake Sonoma
Paddle runs
More reservoirs
Track Cape Horn 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 Cape Horn
Where does the data for Cape Horn 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 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 Cape Horn .