Contra Loma Dike No. 3 Reservoir Report

Last Updated: December 5, 2025

Contra Loma Dike No.


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Summary

3 is a federal-owned structure located in Antioch, California, along the San Joaquin River. Built in 1967 by the Bureau of Reclamation, this dike stands at a height of 10 feet and serves a primary purpose that is not specified in the data. With a storage capacity of 2,630 acre-feet, it plays a crucial role in water resource management in the region.

Although classified as having a low hazard potential, Contra Loma Dike No. 3 is subject to regular inspections by the Bureau of Reclamation, with the last one conducted in August 2020. The dam's emergency action plan was last revised in April 2017, ensuring preparedness for any unforeseen events. Despite its importance in water storage, the condition assessment of the dam is currently listed as "Not Available," indicating a need for further evaluation and monitoring.

With its strategic location and significant storage capacity, Contra Loma Dike No. 3 remains a vital component of the water infrastructure in Contra Costa County. As water resource and climate enthusiasts, monitoring and maintaining the integrity of such structures is essential for ensuring the sustainability and resilience of our water systems in the face of changing environmental conditions.

Year Completed

1967

Dam Length

300

Dam Height

10

River Or Stream

SAN JOAQ RIVER OS

Hydraulic Height

6

Nid Storage

2630

Structural Height

6

Hazard Potential

Low

Nid Height

10
       
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.