Rancho Seco dam
Rancho Seco
Rancho Seco, located in Herald, California, is a public utility dam on Tr Hadselville Cr, managed and regulated by the Department of Water Resources and the Safety of Dams agency. Completed in 1972, this earth dam stands at a height of 58 feet and has a hydraulic height of 50.5 feet, with a total length of 3400 feet and a storage capacity of 2950 acre-feet. The dam serves primarily for tailings storage, with secondary purposes including recreation. Despite its high hazard potential, Rancho Seco has been assessed as being in satisfactory condition as of September 2017.
The dam's surrounding area covers 165 acres and drains an area of 1.8 square miles. The last inspection in November 2020 found the structure to be in good condition, with regular inspections conducted every 1 year. Rancho Seco's Emergency Action Plan was last revised in August 2020, ensuring that necessary measures are in place in case of emergencies. The dam is under the jurisdiction of the state of California and is subject to state permitting, inspection, and enforcement protocols to maintain its safety and functionality, making it an essential component in water resource management and climate resilience efforts in the region.
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 Rancho Seco -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Cosumnes R A Michigan Bar Ca | 168 cfs | → |
| Laguna C Nr Elk Grove Ca | 1 cfs | → |
| Deer C Nr Cameron Park Ca | 8 cfs | → |
| American R A Fair Oaks Ca | 1,920 cfs | → |
| Morrison C Nr Sacramento Ca | 11 cfs | → |
| Sacramento R A Freeport Ca | 5,550 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Rancho Seco.
Boat launches
- Harrington Way 950, Carmichael
- Jedediah Smith Memorial Trail, Gold River
- Watt Avenue, Sacramento
- Willow Creek Boat Ramp
- Pennsylvania Avenue 3885, Fair Oaks
- Rossmoor Drive Rancho Cordova
Campgrounds
- Rancho Seco Rec Area
- Acorn - New Hogan Lake
- Oak Knoll - New Hogan Lake
- Acorn Campground
- Gold Strike Village Campers
- Koa Placerville
Fishing spots
Paddle runs
More reservoirs
Track Rancho Seco 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 Rancho Seco
Where does the data for Rancho Seco 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 Rancho Seco.