Costelloe is a privately owned irrigation dam located in Snyder, Colorado, along the Dead Horse Draw river. Built in 1931, this earth dam stands at a height of 18 feet and has a length of 640 feet, providing a storage capacity of 248 acre-feet for agricultural purposes. With a low hazard potential and fair condition assessment, Costelloe is regulated and inspected by the Colorado Department of Water Resources to ensure its safety and functionality.

The dam features an uncontrolled spillway with a width of 201 feet and a maximum discharge capacity of 2940 cubic feet per second. Despite its moderate risk assessment rating, Costelloe has not undergone any recent modifications or emergency action plan updates. The last inspection in 2015 deemed the structure to be in satisfactory condition, meeting regulatory guidelines and posing minimal threat to downstream areas in the event of a breach.

Costelloe serves as a vital resource for water management in Morgan County, Colorado, contributing to the irrigation needs of the surrounding agricultural community. With its strategic location and operational infrastructure, this dam plays a crucial role in sustaining the local economy and supporting the region's water supply in a sustainable and efficient manner.