Crystal Sprgs Res A Dam Nr San Mateo Ca Reservoir Report

Last Updated: December 5, 2025

Crystal Springs Reservoir is located near San Mateo, California, and was created by the construction of the Crystal Springs Dam in 1878.


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Summary

The reservoir is operated by the San Francisco Public Utilities Commission and serves as a major water supply for the Bay Area, providing up to 23 million gallons of water per day. The area is known for its unique hydrology, as it is fed by both surface flow and snowpack from the nearby Santa Cruz Mountains. The reservoir also serves as a popular recreational destination for activities such as hiking, fishing, and boating, and is surrounded by several parks and nature preserves. While there is some agricultural use in the surrounding area, the primary focus of the reservoir is on providing a reliable water source for the region.

Reservoir Details

Lake Or Reservoir Water Surface Elevation Above Navd 1988, Ft 24hr Change -0.01%
Percent of Normal 100%
Minimum 257.15 ft
2007-10-02
Maximum 292.51 ft
2023-01-17
Average 281 ft
       
Seasonal Comparison
Lake Or Reservoir Water Surface Elevation Above Navd 1988, 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.