Pomponio Ranch, also known as Pomponio Reservoir, is a privately owned dam in San Mateo County, California, situated along Pomponio Creek. Built in 1952, this earth dam stands at a height of 64 feet, with a hydraulic height of 57 feet, and a length of 245 feet. The reservoir has a storage capacity of 274 acre-feet and serves multiple purposes, including flood risk reduction, irrigation, and water supply for the surrounding area.

Managed by the California Department of Water Resources and regulated by the Safety of Dams program, Pomponio Ranch has a high hazard potential due to its location and design. Despite this, the dam's condition assessment in 2017 deemed it satisfactory, with regular inspections ensuring its safety and structural integrity. The dam's emergency action plan status and risk management measures, however, require further evaluation and improvement to meet guidelines and ensure preparedness for any potential emergencies.

Located near the Pacific Ocean, Pomponio Ranch continues to play a crucial role in managing water resources and mitigating flood risks in the region. As water resource and climate enthusiasts, understanding and monitoring the infrastructure and safety measures of dams like Pomponio Ranch are essential for sustainable water management and environmental conservation efforts in California's diverse landscape.