Whale Rock dam
Whale Rock
Whale Rock, located in Cayucos, California, is a vital water resource structure primarily used for irrigation and water supply purposes. This earth dam stands at a height of 193 feet, with a hydraulic height of 176 feet, and a length of 850 feet. Completed in 1960, Whale Rock has a storage capacity of 40,662 acre-feet and covers a surface area of 594 acres, serving a drainage area of 20.8 square miles.
Managed by a public utility and regulated by the California Department of Water Resources (DWR) under the Safety of Dams program, Whale Rock has a high hazard potential but was assessed to be in satisfactory condition as of September 2017. The dam undergoes regular inspections, with the last one conducted in November 2020, ensuring its safety and reliability for the surrounding community. With its critical role in water supply and irrigation, Whale Rock remains a key infrastructure for water resource management in San Luis Obispo County.
Despite its age, Whale Rock continues to play a crucial role in water management and supply in the region, showcasing the importance of maintaining and monitoring such structures for long-term sustainability. As climate change impacts water resources, the resilience of dams like Whale Rock becomes increasingly significant in mitigating risks and ensuring water availability for agricultural and municipal needs. The careful oversight and maintenance of Whale Rock by regulatory agencies and stakeholders contribute to the overall safety and security of water resources in the area.
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 Whale Rock -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Salinas R A Paso Robles Ca | 1 cfs | → |
| Nacimiento R Bl Nacimiento Dam Nr Bradley Ca | 264 cfs | → |
| Estrella R Nr Estrella Ca | 0 cfs | → |
| Nacimiento R Bl Sapaque C Nr Bryson Ca | 2 cfs | → |
| Lopez C Nr Arroyo Grande Ca | 3 cfs | → |
| San Antonio R Nr Lockwood Ca | · | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Whale Rock.
Boat launches
- Village Road San Luis Obispo County
- Resort Drive, Paso Robles
- Mistletoe Lane San Luis Obispo County
- Saddle Way San Luis Obispo County
- Resort Drive San Luis Obispo County
- West Knoll Circle 10555, San Luis Obispo County
Campgrounds
- Morro Strand State Beach
- Morro Bay State Park
- Cerro Alto
- Cerro Alto Campground
- Montana De Oro State Park
- Camp San Luis Obispo Rv Military
Fishing spots
- Whale Rock Reservoir
- Atascadero Lake
- Franklin Hot Springs
- Barney Schwartz Park Lake
- Nacimiento Lake
- Lake Nacimiento
More reservoirs
Track Whale Rock 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 Whale Rock
Where does the data for Whale Rock 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 Whale Rock.