Jayne's Lake Reservoir Report

Last Updated: December 13, 2025

Jayne's Lake, located in Mendocino County, California, is a private dam that was completed in 1985 for flood risk reduction along Toney Creek.


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Summary

Standing at a height of 70 feet with a storage capacity of 1225 acre-feet, this earth dam plays a crucial role in irrigation and water supply for the surrounding area. Despite being regulated by the state and subject to regular inspections, Jayne's Lake is classified as having a low hazard potential and is in satisfactory condition as of the last assessment in September 2017.

Owned by a private entity, Jayne's Lake serves as a vital infrastructure for managing water resources in the region, with its primary purpose being flood risk reduction. The dam spans a length of 650 feet and covers a surface area of 55 acres while also providing essential irrigation and water supply functions. Situated in the city of Hearst, this dam is under the jurisdiction of the California Department of Water Resources and is inspected regularly to ensure its safety and compliance with state regulations.

Managed by the Sacramento District of the US Army Corps of Engineers, Jayne's Lake has not undergone significant modifications since its completion. With a designated emergency action plan yet to be prepared, the dam is deemed to have satisfactory risk management measures in place. As a key component in the water infrastructure of Mendocino County, Jayne's Lake stands as a testament to the importance of sustainable water resource management in the face of climate variability and changing environmental conditions.

Year Completed

1985

Dam Length

650

Dam Height

70

River Or Stream

Toney Creek

Primary Dam Type

Earth

Surface Area

55

Hydraulic Height

65

Nid Storage

1225

Hazard Potential

Low

Nid Height

70
       
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.