Eagle Lake Dam, also known as Eagle Lake Reservoir, is a privately owned structure located in Union, Oregon. Completed in 1920, this earth dam stands at a height of 33 feet and serves primarily for irrigation purposes. With a storage capacity of 844 acre-feet and a surface area of 35.3 acres, Eagle Lake Dam holds back the waters of the Eagle Lake stream, providing essential water resources for the surrounding area.

Managed by the Oregon Water Resources Department, Eagle Lake Dam is regulated, inspected, and enforced by the state to ensure its safety and functionality. The dam features a slide (sluice gate) outlet gates and has a low hazard potential. Despite not being rated for condition assessment, the dam is subject to regular inspections every six years to maintain its integrity. Located within the Walla Walla District, Eagle Lake Dam plays a vital role in water resource management and irrigation in the region.

As a key component of the water infrastructure in the area, Eagle Lake Dam plays a crucial role in managing water resources for agricultural purposes. With its historical significance dating back to the early 20th century, the dam continues to provide essential water storage and distribution for the local community. As climate change impacts water availability, the maintenance and regulation of Eagle Lake Dam remain vital for ensuring a sustainable water supply in the region.