Andrus, located in Johnson, Wyoming, is a privately owned Earth dam completed in 1958 for irrigation purposes on the Andrus Draw river. With a height of 27 feet and a storage capacity of 76 acre-feet, this dam serves multiple functions including fire protection, stock watering, and flood risk reduction. The dam's spillway, with a width of 75 feet, is uncontrolled and can handle a maximum discharge of 430 cubic feet per second.

Despite its low hazard potential, Andrus has an unsatisfactory condition assessment as of July 2017 and is inspected every 5 years. The dam is regulated by the State of Wyoming, with state jurisdiction, permitting, inspection, and enforcement in place. While the risk assessment for Andrus is moderate, the dam lacks emergency action plans and updated contact information, posing a potential safety concern that needs to be addressed. Water resource and climate enthusiasts interested in the maintenance and management of dams for irrigation and flood control purposes would find Andrus an intriguing case study for understanding the complexities of dam infrastructure in the region.