Piedmont Reservoir Report

Last Updated: December 5, 2025

Piedmont, also known as Reservoir No 2, is a public utility water supply reservoir located in Oakland, California.


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Summary

Built in 1905, this offstream dam stands at a height of 64 feet and has a maximum storage capacity of 60 acre-feet. The dam serves as a crucial water source for the region, with a primary purpose of water supply.

Managed by the California Department of Water Resources (DWR) under the Safety of Dams program, Piedmont is regulated, permitted, inspected, and enforced upon by the state. With a low hazard potential and a satisfactory condition assessment as of September 2017, the dam is deemed to be in good standing. The last inspection took place on October 16, 2019, with a frequency of every 1 year.

Situated in Alameda County, Piedmont plays a vital role in the water resource management of the area. With its historical significance and ongoing operational efficiency, the reservoir serves as a testament to responsible water infrastructure development and maintenance in the face of climate challenges and evolving regulatory standards.

Year Completed

1905

Dam Length

250

Dam Height

64

River Or Stream

Offstream

Primary Dam Type

Earth

Surface Area

3

Hydraulic Height

62

Nid Storage

60

Hazard Potential

Low

Nid Height

64
       
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.