Goodwin Reservoir Report

Last Updated: December 5, 2025

Goodwin, located in Knights Ferry, California, is a public utility dam on the Stanislaus River that serves multiple purposes, including flood risk reduction, irrigation, and water supply.


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Summary

Built in 1912, this multi-arch dam stands at a height of 101 feet and has a storage capacity of 500 acre-feet. With a drainage area of 996.5 square miles, Goodwin plays a crucial role in managing water resources in Calaveras County.

Managed by the California Department of Water Resources (DWR) under the Safety of Dams program, Goodwin is subject to regular state inspections, enforcement, and permitting to ensure its structural integrity and operational safety. Despite being classified with a high hazard potential, the dam's condition was assessed as satisfactory in 2017. Emergency action plans are in place, with the last revision conducted in September 2020, to address any potential risks and ensure swift responses in case of emergencies.

With a historical significance dating back over a century, Goodwin continues to be a vital infrastructure for the local community in managing water resources and mitigating flood risks along the Stanislaus River. As water resource and climate enthusiasts, understanding the operational and safety measures surrounding dams like Goodwin is essential for promoting sustainable water management practices and ensuring the resilience of our water infrastructure in the face of changing climate conditions.

Year Completed

1912

Dam Length

460

Dam Height

101

River Or Stream

Stanislaus Rv

Primary Dam Type

Multi-Arch

Surface Area

70

Hydraulic Height

81.1

Drainage Area

996.5

Nid Storage

500

Hazard Potential

High

Nid Height

101
       
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.