Don Pedro Res Nr La Grange Ca Reservoir Report

Last Updated: December 5, 2025

Don Pedro Reservoir is a man-made lake situated in the Sierra Nevada foothills of California, about 10 miles from La Grange.


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Summary

This reservoir was created by the construction of the Don Pedro Dam on the Tuolumne River in 1923. It has a storage capacity of 2,030,000 acre-feet and is one of the largest water storage facilities in California. The reservoir serves as a critical source of water for irrigation, hydroelectric power generation, and municipal supply. It is also a popular recreational destination, offering activities such as fishing, boating, camping, and hiking. The reservoir receives its water from various sources, including snowmelt from the Sierra Nevada mountains, rainfall, and surface flow from the Tuolumne River. The snowpack providers are the Sierra Nevada Mountains, and the surface flow is provided by the Tuolumne River. The water from the reservoir is used for agricultural purposes in the Central Valley and in cities such as San Francisco and Modesto.

Reservoir Details

Lake Or Reservoir Water Surface Elevation Above Ngvd 1929, Ft 24hr Change 0.0%
Percent of Normal 103%
Minimum 670.95 ft
2015-10-10
Maximum 829.76 ft
2017-02-23
Average 760 ft
Dam_Height 585
Hydraulic_Height 560
Drainage_Area 1540
Year_Completed 1971
Nid_Storage 2300000
Structural_Height 585
River_Or_Stream Tuolumne River
Foundations Rock
Surface_Area 13000
Hazard_Potential High
Outlet_Gates Tainter (radial) - 3
Dam_Length 1900
Primary_Dam_Type Earth
Nid_Height 585
       
Seasonal Comparison
Reservoir Storage, Acre-Ft Levels
Lake Or Reservoir Water Surface Elevation Above Ngvd 1929, Ft 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.