Nash, also known as Nash Upper Dam, is a private water resource structure located in Franklin, Idaho. The dam, completed in 1952, serves primarily for irrigation purposes and is regulated by the Idaho Department of Water Resources. With a height of 20.5 feet and a storage capacity of 93.8 acre-feet, Nash plays a crucial role in managing water resources in the area.

Situated on Fivemile Creek, a tributary of the Bear River, Nash has a low hazard potential and is classified as having a fair condition assessment. The dam features an uncontrolled spillway type with a width of 14 feet and outlet gates equipped with slide (sluice gate) mechanisms. Despite its moderate risk assessment, Nash has not been modified in recent years and undergoes inspections every five years to ensure its structural integrity and safety for the surrounding community.

Managed under private ownership, Nash contributes to the overall water management infrastructure in Idaho, providing essential irrigation water for agricultural activities in the region. With its stone core and earth dam type, Nash stands as a testament to the important role dams play in supporting water resource management and climate resilience efforts in the area.