Bonita Long Canyon Reservoir Report

Last Updated: December 5, 2025

Bonita Long Canyon, located in Bonita, California, is a local government-owned earth dam constructed in 1986 with the primary purpose of flood risk reduction along the Tr Sweetwater River.


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Summary

Standing at a height of 29 feet and a hydraulic height of 23.5 feet, the dam spans 400 feet in length and has a storage capacity of 49 acre-feet. Despite its modest size, the dam serves an important role in safeguarding the surrounding community from potential flooding events.

Managed by the California Department of Water Resources (DWR) and subject to state regulation, inspection, and enforcement, Bonita Long Canyon Dam has been assessed as having a low hazard potential with a satisfactory condition as of September 2017. The dam boasts a well-maintained status, evidenced by the last inspection conducted in March 2021. With a steady track record of safety and operational effectiveness, the dam continues to fulfill its critical function of mitigating flood risks in the region. For water resource and climate enthusiasts, Bonita Long Canyon serves as a noteworthy example of local infrastructure contributing to the resilience and protection of communities against natural disasters.

Year Completed

1986

Dam Length

400

Dam Height

29

River Or Stream

Tr Sweetwater Rv

Primary Dam Type

Earth

Surface Area

3

Hydraulic Height

23.5

Nid Storage

49

Hazard Potential

Low

Nid Height

29
       
Seasonal Comparison

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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.