Koskella is a privately owned irrigation dam located in Valley, Idaho, along an unnamed stream north of the North Fork Payette River. Built in 1947, this earth and stone dam stands at a height of 24 feet and has a hydraulic height of 20.7 feet. With a storage capacity of 74 acre-feet and a drainage area of 0.4 square miles, Koskella serves the primary purpose of irrigation in the region.

Despite its age, Koskella has been regularly inspected and maintained by the Idaho Department of Water Resources, with the last inspection conducted in November 2016. The dam has been assessed to be in fair condition with a low hazard potential. The spillway, which is uncontrolled, has a width of 10 feet to manage a maximum discharge of 55 cubic feet per second. The risk assessment for Koskella indicates a moderate risk level, with appropriate risk management measures in place to ensure the safety and integrity of the structure.

Overall, Koskella is a crucial water resource infrastructure in Idaho, providing irrigation water for agricultural activities in the region. With its moderate risk level and fair condition, ongoing monitoring and maintenance efforts are essential to ensure the continued functionality and safety of this important dam in the face of changing climate conditions and water resource demands.