Long Valley West No. 2 Reservoir Report

Last Updated: December 5, 2025

Long Valley West No.


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Summary

2 is a privately owned earth dam located in Napa, California, along the Tr Pope Creek. Completed in 1982, this dam stands at a height of 35 feet and has a storage capacity of 177 acre-feet, primarily used for irrigation and water supply purposes. With a low hazard potential and a satisfactory condition assessment, this dam has been regulated by the California Department of Water Resources (DWR) under the Safety of Dams program, ensuring regular inspections and enforcement to maintain its safety and integrity.

Situated within the San Francisco District, Long Valley West No. 2 serves as a crucial water resource infrastructure, supporting the local agricultural activities in the region. The dam's design and construction reflect its importance in providing reliable water supply to the surrounding areas. Despite its modest size, the dam plays a significant role in managing water resources and ensuring sustainable usage for irrigation and other purposes. With state jurisdiction and regulatory oversight, Long Valley West No. 2 exemplifies the commitment to maintaining water infrastructure standards and safety in California.

As a key component of the water supply system in Napa County, Long Valley West No. 2 has been integral in meeting the agricultural and irrigation needs of the region. With a history of satisfactory condition assessments and regular inspections, this dam showcases the importance of proactive management and maintenance in ensuring the resilience of water infrastructure against the backdrop of changing climate conditions. Its strategic location and purposeful design underscore the essential role that dams play in supporting water resource management efforts and climate resilience initiatives in California.

Year Completed

1982

Dam Length

940

Dam Height

35

River Or Stream

Tr Pope Creek

Primary Dam Type

Earth

Surface Area

10

Hydraulic Height

31

Nid Storage

177

Hazard Potential

Low

Nid Height

35
       
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.