Galivan Retarding Basin Reservoir Report

Last Updated: December 5, 2025

Galivan Retarding Basin, located in Laguna Niguel, California, along the Oso Creek, serves as a crucial water resource infrastructure owned by the local government.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 2000, this earth dam stands at 14 feet high and has a storage capacity of 169 acre-feet, primarily used for water supply purposes. With a drainage area of 13.4 square miles and a surface area of 17 acres, this basin plays a vital role in water management within Orange County.

Managed and regulated by the California Department of Water Resources, the Galivan Retarding Basin has a low hazard potential and is deemed to be in satisfactory condition as of the last assessment in September 2017. Despite its relatively modest size, this structure contributes to flood control and water storage in the region, ensuring the safety and security of the surrounding communities. With regular inspections and maintenance, the basin continues to fulfill its intended purpose effectively.

Situated within the Los Angeles District of the US Army Corps of Engineers, the Galivan Retarding Basin exemplifies the intersection of water resource management and climate resilience. With its strategic location and design, this infrastructure project underscores the importance of sustainable water infrastructure to address the challenges posed by a changing climate. As water resource and climate enthusiasts, the Galivan Retarding Basin offers a compelling case study in the critical role of local government in safeguarding water supplies and enhancing community resilience in the face of environmental uncertainties.

Year Completed

2000

Dam Length

600

Dam Height

14

River Or Stream

Oso Creek

Primary Dam Type

Earth

Surface Area

17

Hydraulic Height

8.7

Drainage Area

13.4

Nid Storage

169

Hazard Potential

Low

Nid Height

14
       
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.