Glen Martin Reservoir Report

Last Updated: December 5, 2025

Glen Martin, also known as Shadow Lake, is a private water supply dam located in Yucaipa, California.


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Summary

Built in 1950, this earth-type dam stands at a height of 55 feet and has a hydraulic height of 49 feet, with a storage capacity of 33 acre-feet. The dam serves the primary purpose of water supply, while also providing opportunities for recreation in the area.

Managed by the California Department of Water Resources (DWR) under the Safety of Dams program, Glen Martin Dam is regulated, permitted, inspected, and enforced by the state authorities to ensure its safety and compliance with regulations. With a fair condition assessment and a high hazard potential, the dam undergoes regular inspections to monitor its structural integrity and mitigate any risks associated with its operation.

Situated on Mountain Home Creek in San Bernardino County, Glen Martin Dam plays a crucial role in water resource management in the region. With its significant storage capacity and strategic location, the dam not only supports water supply needs but also contributes to the overall ecosystem health and recreational activities in the area. Enthusiasts in water resources and climate can appreciate the importance of Glen Martin Dam in sustaining water availability and ecological balance in the region.

Year Completed

1950

Dam Length

302

Dam Height

55

River Or Stream

Mountain Home Cr

Primary Dam Type

Earth

Surface Area

2

Hydraulic Height

49

Drainage Area

0.3

Nid Storage

33

Hazard Potential

High

Nid Height

55
       
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.