North Platte River
The source of water for Lake McConaughy is primarily the North Platte River. Water flows into the lake from a drainage area west of the dam. U.S. Bureau of Reclamation reservoirs on the North Platte River in Wyoming capture precipitation and snowmelt from the mountains and utilize the water for irrigation and hydroelectric production within the North Platte Projects. Return flows from these projects to the North Platte River make up a significant portion of the inflows to Lake McConaughy.