Sunset South Basin Reservoir Report

Last Updated: December 15, 2025

Sunset South Basin, located in San Francisco, California, is a crucial water supply infrastructure owned by the local government.


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Summary

This offstream dam, completed in 1960, stands at a height of 34 feet and has a storage capacity of 268 acre-feet. The dam serves the primary purpose of water supply, ensuring a reliable source of water for the surrounding area.

Managed by the California Department of Water Resources (DWR) under the Safety of Dams program, Sunset South Basin is subject to regular inspections and state regulations to maintain its structural integrity and operational safety. With a high hazard potential, the dam has been assessed as satisfactory in condition as of September 2017. In case of emergencies, preparedness measures are in place, although specific details regarding emergency action plans and risk assessments are not provided in the available data.

Despite its relatively small surface area of 12 acres, Sunset South Basin plays a significant role in water resource management in the region. With Nancy Pelosi representing the district, this dam signifies the ongoing efforts to sustainably manage water resources and mitigate risks associated with infrastructure in the face of changing climate patterns.

Year Completed

1960

Dam Length

980

Dam Height

34

River Or Stream

Offstream

Primary Dam Type

Earth

Surface Area

12

Hydraulic Height

32

Nid Storage

268

Hazard Potential

High

Nid Height

34
       
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.