Thorald Dam, located in Washington's San Juan County, serves as an essential irrigation source with a primary purpose of supplying water for agricultural needs. Completed in 1988, this earth dam stands at a hydraulic height of 19 feet and a structural height of 16 feet, with a length of 400 feet. The dam boasts a storage capacity of 98 acre-feet, providing water for irrigation and recreation purposes in the region.

Managed by a private entity, Thorald Dam is regulated by the Washington Department of Ecology, ensuring state jurisdiction, permitting, inspection, and enforcement. With a low hazard potential and a condition assessment of "Not Rated," the dam poses minimal risk to the surrounding area. Despite not being rated, the dam's emergency action plan (EAP) status, risk assessment, and risk management measures are currently unspecified, indicating a potential area for improvement in terms of disaster preparedness.

Nestled along the Tr-Parks Bay river or stream, Thorald Dam plays a crucial role in water resource management in the region. With its strategic location and solid construction, this dam stands as a testament to human ingenuity in harnessing water resources for the benefit of local communities while maintaining a low risk profile. For water resource and climate enthusiasts, Thorald Dam offers a fascinating case study in dam engineering and management within the picturesque landscape of San Juan County, Washington.