Deer Flat Lower, also known as Lake Lowell Lower Dam, is a Federal-owned structure located in Canyon, Idaho. Completed in 1907, this dam plays a crucial role in water resource management and climate resilience in the area. With a dam height of 50 feet and a storage capacity of 173,200 acre-feet, it helps regulate water flow from the Boise River and Snake River, covering a surface area of 9,800 acres and serving a drainage area of 75 square miles.

The dam is primarily made of earth and stone materials, with a rock and soil foundation. It features an outlet gate system for water release, and although it has no spillway, its hazard potential is considered high due to its age and condition. The dam is inspected every two years, with the latest assessment in 2019 rating its condition as fair. Despite the risks associated with its high hazard potential, Deer Flat Lower plays a vital role in water storage and management for the region, highlighting the importance of ongoing maintenance and monitoring to ensure its continued safety and functionality.

Managed by the Walla Walla District of the US Army Corps of Engineers, Deer Flat Lower serves as a key infrastructure for flood control, irrigation, and water supply in the region. Its location in Wilder, Idaho, and proximity to the Boise and Snake Rivers make it a critical component of the local ecosystem and economy. As water resource and climate enthusiasts, understanding the significance of structures like Deer Flat Lower is essential for advocating for sustainable water management practices and climate resilience strategies in the face of changing environmental conditions.