Heidenreich Dam, located in San Juan, Washington, is a privately owned earth dam that was completed in 1972 for the primary purpose of recreation. Situated on the Tr-Strait of Juan De Fuca, this dam stands at a hydraulic height of 16 feet and a structural height of 11 feet, with a length of 215 feet. It has a storage capacity of 108 acre-feet, with a normal storage level of 92 acre-feet, covering a surface area of 18 acres and serving a drainage area of 0.35 square miles.

Although the dam's hazard potential is rated as low and its condition is not officially assessed, it is regulated by the Washington Department of Ecology and undergoes periodic inspections. The last recorded inspection was in January 2000, with an unknown inspection frequency. Despite its low-risk classification, the dam does not have an Emergency Action Plan (EAP) in place, and other risk management measures are not specified. With its picturesque location and recreational focus, Heidenreich Dam provides both a peaceful retreat and a potential asset for water resource and climate enthusiasts to explore and appreciate.