Coen C-3 is a privately owned earth dam located in Healdsburg, California, along the Tr Dry Creek. Built in 1982, this dam stands at a height of 97 feet and has a storage capacity of 480 acre-feet, primarily serving the purpose of water supply for irrigation and other uses in the area. With a low hazard potential and a satisfactory condition assessment as of September 2017, Coen C-3 is regulated by the California Department of Water Resources (DWR) and undergoes regular inspections to ensure its safety and functionality.

Situated in Sonoma County, Coen C-3 boasts a surface area of 16 acres and a drainage area of 0.32 square miles. Despite its relatively small size, this dam plays a crucial role in providing water resources for the surrounding community. Managed by a private entity, Coen C-3 is subject to state jurisdiction, permitting, inspection, and enforcement to meet regulatory standards set by the DWR. The dam's location within the San Francisco District and its proximity to Healdsburg highlight its significance in water management and supply for the region.

With its efficient design and satisfactory condition, Coen C-3 stands as a testament to effective water resource management in California. The dam's low hazard potential, along with its regular inspections and state regulatory oversight, ensures the safety and reliability of its water supply operations. As climate change continues to impact water resources, structures like Coen C-3 play a vital role in securing and managing water supplies for the future, making it a key asset for water resource and climate enthusiasts alike.