Greenhorn dam
Greenhorn
Greenhorn Reservoir, located in Yreka, California, is a vital water resource managed by the local government for water supply and recreation purposes. The earth dam, completed in 1960, stands at a height of 35 feet and has a storage capacity of 251 acre-feet. Situated on Greenhorn Creek, the reservoir covers an area of 25 acres and serves as a key source of water for the surrounding community.
With a high hazard potential, the dam undergoes regular inspections by the Department of Water Resources to ensure its structural integrity. The latest assessment in September 2017 deemed the dam's condition as satisfactory, providing confidence in its ability to withstand potential risks and emergencies. Despite its critical role in water management, the reservoir also offers recreational opportunities for visitors to enjoy the scenic beauty of the area.
Managed by the Natural Resources Conservation Service, Greenhorn Reservoir plays a crucial role in water supply and environmental conservation efforts in the region. As climate change continues to impact water resources, the sustainable management of reservoirs like Greenhorn becomes increasingly important to ensure the resilience of communities and ecosystems in the face of evolving environmental challenges.
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 Greenhorn -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Shasta R Nr Montague Ca | 63 cfs | → |
| Shasta R Nr Yreka Ca | 68 cfs | → |
| Klamath R Bl Iron Gate Dam Ca | 1,450 cfs | → |
| Scott R Nr Fort Jones Ca | 198 cfs | → |
| West Fork Ashland Creek Near Ashland | 5 cfs | → |
| East Fork Ashland Creek Near Ashland | 4 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Greenhorn.
Boat launches
- A. Ash Creek River Access
- B. Cayuse River Access
- C. Skeahan Bar River Access
- D. Gottville River Access
- E. Brown Bear River Access
- Mountain Wood Drive 15182, Siskiyou County
Campgrounds
- Tree Of Heaven
- Tree Of Heaven Campground
- Sarah Totten
- Sarah Totten Campground
- Joss - Johnson Park (Etna City Park)
- Indian Scotty
Fishing spots
Paddle runs
- Shasta River
- Iron Gate Dam To Happy Camp
- Little Applegate River
- Headwaters In Marble Mtn. Wilderness To Wilderness Boundary
- Headwaters In Marble Mtn. Wilderness To Confluence With Fish Creek
- Confluence With Rancheria Creek To Forest Road 46n24x
More reservoirs
Track Greenhorn 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 Greenhorn
Where does the data for Greenhorn 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 Greenhorn.