Nacimiento Reservoir Report

Last Updated: December 5, 2025

Nacimiento Dam, located in San Luis Obispo, California, is a vital water resource structure managed by the local government.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1956, this Earth dam stands at a impressive height of 210 feet and serves multiple purposes including flood risk reduction, hydroelectric power generation, irrigation, recreation, and water supply. With a storage capacity of 470,000 acre-feet and a maximum discharge rate of 102,400 cubic feet per second, Nacimiento Dam plays a crucial role in water management in the region.

Owned and regulated by the Federal Energy Regulatory Commission, Nacimiento Dam is subject to regular inspections to ensure its safety and functionality. With a high hazard potential and a very high risk assessment rating, the dam is closely monitored for any potential issues. While the condition assessment is not currently available, emergency action plans are in place to address any unforeseen events. The surrounding area benefits from the dam's presence, with a surface area of 5,400 acres and a drainage area of 330 square miles.

Overall, Nacimiento Dam is a key infrastructure project that not only provides essential water management services but also supports various recreational activities and environmental benefits. As climate change continues to impact water resources, structures like Nacimiento Dam will play a crucial role in ensuring water security and sustainability for the region.

Year Completed

1956

Dam Length

1630

Dam Height

210

River Or Stream

Nacimiento River

Primary Dam Type

Earth

Surface Area

5400

Hydraulic Height

185

Drainage Area

330

Nid Storage

470000

Structural Height

255

Hazard Potential

High

Foundations

Soil

Nid Height

255
       
Seasonal Comparison

Weather Forecast

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. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
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. Investigations and studies are necessary.
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.
Not Available
Dams for which the condition assessment is restricted to approved government users.

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, environment 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.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.