Robert L. Matheson is a private water supply dam located in Napa, California, along the Elder Creek. Built in 1954, this earth-type dam stands at a height of 32 feet with a hydraulic height of 25.7 feet. With a storage capacity of 90 acre-feet, it serves primarily for irrigation and water supply purposes, covering a surface area of 12 acres and draining from a 1.7 square mile watershed.

Managed by the California Department of Water Resources, Robert L. Matheson is regulated, permitted, inspected, and enforced by state authorities to ensure its safety and compliance with regulations. Despite its significant hazard potential, the dam's condition has been assessed as satisfactory, with the last inspection conducted in July 2020. The dam's emergency action plan status and risk assessments are currently unspecified.

Situated within the Sacramento District, Robert L. Matheson is designed by the Natural Resources Conservation Service and is recognized for its role in water resource management in the region. With its historical significance and ongoing maintenance, this dam serves as a vital infrastructure for water supply and agricultural irrigation, contributing to the sustainability of California's water resources amidst changing climate patterns.