The Soulen Auxiliary Dike, also known as the Soulen South Dike, is a crucial water management structure located in Washington County, Idaho. This private-owned dike was completed in 1935 with the primary purpose of aiding in irrigation efforts in the region. The dike stands at a height of 6.5 feet and has a hydraulic height of 3.7 feet, providing storage for 240 acre-feet of water from the South Crane Creek and Crane Creek.

With a fair condition assessment and low hazard potential, the Soulen Auxiliary Dike plays a vital role in maintaining water resources for agricultural activities in the area. Despite its age, the dike continues to be regulated, inspected, and enforced by the Idaho Department of Water Resources to ensure its structural integrity and safety. The dike's moderate risk assessment underscores the importance of ongoing monitoring and management to prevent any potential issues that could impact the surrounding community and environment.