Mud is an earth-type dam located in San Joaquin, California, along the Fresno Slough. Built in 1919, this public utility structure serves primarily for water supply, with a storage capacity of 304 acre-feet and a height of 14 feet. The dam spans 127 feet in length and covers a surface area of 38 acres, contributing to irrigation and water supply purposes in the region.

Managed by the Department of Water Resources and Safety of Dams, Mud is deemed to have low hazard potential and is currently in satisfactory condition as of the last assessment in September 2017. Regular inspections are conducted, with the most recent one in April 2020, ensuring the safety and functionality of the dam. While no emergency action plan or inundation maps have been reported, the structure meets state permitting, inspection, and enforcement regulations, providing a reliable water resource for the surrounding area.

Situated within the Sacramento District and represented by Congressman TJ Cox, Mud demonstrates a crucial link in the water infrastructure of Fresno County. With its historic significance dating back over a century, the dam continues to play a vital role in sustaining water resources for irrigation and supply purposes, showcasing the importance of earth-based structures in maintaining water security in California's diverse climate and hydrology.