Eucha, also known as Upper Spavinaw Lake, is a local government-owned water supply reservoir located in Delaware County, Oklahoma. Managed by the city of Spavinaw, this dam was completed in 1952 and serves as a crucial source of water for the surrounding area. With a capacity of 119,000 acre-feet and a normal storage of 79,600 acre-feet, Eucha plays a vital role in meeting the water needs of the community.

Situated on the Spavinaw Creek, Eucha has a dam height of 95 feet and a structural height of 95 feet. The reservoir covers a surface area of 2,860 acres and has a drainage area of 360 square miles. With a controlled spillway and a maximum discharge capacity of 298,000 cubic feet per second, the dam is designed to manage high hazard potential while maintaining fair condition assessment. In the event of emergencies, the dam is equipped with a valve outlet gate for efficient water release.

Despite its fair condition, Eucha poses a very high risk due to its age and high hazard potential. Regular inspections and maintenance are essential to ensure the safety and reliability of this critical water resource. With its strategic location and significant storage capacity, Eucha continues to play a key role in securing water supply for the region while facing challenges associated with climate change and increasing water demand.