Alta Loma Basin #1 Reservoir Report

Last Updated: December 25, 2025

Alta Loma Basin #1 is a vital flood risk reduction structure located in Alta Loma, California, along the Alta Loma Channel.


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Summary

Completed in 1964, this earth dam stands at a height of 30 feet and has a storage capacity of 70 acre-feet. With a drainage area of 1.98 square miles, it plays a crucial role in mitigating potential flooding in the region, making it a key asset for water resource management in San Bernardino County.

Managed by the local government with state regulation and enforcement, Alta Loma Basin #1 has a high hazard potential but is currently assessed to be in satisfactory condition as of September 2017. Regular inspections are conducted, with the last one taking place in December 2019, ensuring the dam's structural integrity and functionality. The primary purpose of this dam is flood risk reduction, showcasing its importance in safeguarding the surrounding communities from potential water-related disasters.

With its strategic location and effective design, Alta Loma Basin #1 stands as a critical infrastructure for flood control in the region. Its history of service and maintenance, along with its significant storage capacity, highlights its importance in preserving water resources and ensuring climate resilience in the face of potential natural disasters. For water resource and climate enthusiasts, this dam serves as a prime example of sustainable infrastructure that plays a crucial role in protecting communities and enhancing water security.

Year Completed

1964

Dam Length

2600

Dam Height

30

River Or Stream

Alta Loma Channel

Primary Dam Type

Earth

Surface Area

23

Hydraulic Height

23

Drainage Area

1.98

Nid Storage

70

Hazard Potential

High

Nid Height

30
       
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.