Juncal Reservoir Report

Last Updated: December 5, 2025

Juncal, also known as Jameson Lake, is a significant public utility located in Santa Barbara, California, specifically in the city of Summerland.


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Summary

This dam serves multiple purposes, including flood risk reduction, irrigation, and water supply, showcasing its vital role in managing water resources in the region. Built in 1930, Juncal is an arch-type dam standing at a height of 160 feet with a hydraulic height of 154 feet, offering a storage capacity of 6140 acre-feet and covering a surface area of 138 acres.

With a high hazard potential but a satisfactory condition assessment as of September 2017, Juncal is regulated, permitted, inspected, and enforced by the California Department of Water Resources (DWR) under the Safety of Dams program. The dam is situated on the Santa Ynez River, providing critical flood protection for the surrounding areas and supporting agricultural activities through irrigation. Managed by a public utility entity, Juncal plays a crucial role in water management and climate resilience efforts in California.

Despite its age, Juncal continues to meet safety standards and undergo regular inspections, with the most recent one conducted in June 2020. With its strategic location and significant storage capacity, Juncal serves as a key infrastructure for flood control and water supply in Santa Barbara County. As water resource and climate enthusiasts, it is essential to recognize the importance of dams like Juncal in ensuring water security and mitigating the impacts of climate change on water availability in the region.

Year Completed

1930

Dam Length

430

Dam Height

160

River Or Stream

Santa Ynez Rv

Primary Dam Type

Arch

Surface Area

138

Hydraulic Height

154

Drainage Area

13.9

Nid Storage

6140

Hazard Potential

High

Nid Height

160
       
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.