Berryessa Reservoir Report

Last Updated: December 5, 2025

Berryessa is a reservoir located in Napa County, California, with a capacity of 1.6 million acre-feet.


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Summary

The history of the reservoir dates back to the 1950s when it was constructed as part of the Solano Project. The primary purpose of the reservoir is to provide water for irrigation and municipal use. The water is supplied from the Cache Creek and Putah Creek watersheds, which are the primary surface flow and snowpack providers, respectively. The reservoir also supports recreational activities such as boating, fishing, and camping. Additionally, the surrounding area is home to agricultural activities, including cattle grazing and vineyards. Berryessa serves as a vital water source for the region, and its management is critical to ensure the sustainability of the water supply.

Reservoir Details

Storage 24hr Change -0.11%
Percent of Normal 127%
Minimum 789,195.0 acre-ft
2022-11-30
Maximum 1,675,491.0 acre-ft
2004-02-18
Average 1,147,850 acre-ft
       
Seasonal Comparison
Storage Levels
Pool Elevation Levels
Top Conserv Storage Levels
Inflow Levels

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.