Chaplain Lake South Dam, located in Sultan, Washington, serves as a critical water supply infrastructure for the region. Completed in 1930, this earth dam stands at a hydraulic height of 75 feet and has a structural height of 50 feet, with a storage capacity of 17,800 acre-feet. The dam is situated on Chaplain Creek, with a drainage area of 2.6 square miles, providing essential water resources for the surrounding communities.

Managed by the Washington Department of Ecology, Chaplain Lake South Dam is regulated and inspected regularly to ensure its structural integrity and safety. With a high hazard potential, the dam's condition is assessed as satisfactory, with the last inspection conducted in July 2019. Despite its age, the dam continues to effectively meet its primary purpose of water supply, demonstrating its importance in maintaining a reliable water source for the area.

As a key component of the local water infrastructure, Chaplain Lake South Dam plays a crucial role in water management and supply for Snohomish County, Washington. With its strategic location and significant storage capacity, the dam serves as a vital resource for the region, highlighting the importance of ongoing monitoring and maintenance to ensure its continued functionality and safety in the face of evolving climate conditions and water resource management challenges.