Tonier Gulch, located in McCoy, Colorado, is a private earth dam built in 1946 for irrigation purposes on Toponas Creek. The dam stands at a height of 32 feet with a length of 325 feet, providing a storage capacity of 124 acre-feet. With a spillway type classified as 'Uncontrolled' and a hazard potential rated as 'Low', Tonier Gulch is deemed to be in fair condition according to a 2018 assessment. The dam's inspection frequency is every 6 years, with the last inspection conducted in July 2018.

Despite its moderate risk assessment, Tonier Gulch remains a vital water resource in Routt County, serving the agricultural community in the region. The dam's stone core and rock-soil foundation contribute to its structural integrity, ensuring its reliability in water storage and distribution. With a maximum discharge capacity of 390 cubic feet per second and an associated slide gate outlet, Tonier Gulch plays a crucial role in managing water flow for irrigation activities along Toponas Creek. As climate change continues to impact water resources, the maintenance and enforcement of regulations for dams like Tonier Gulch are essential to sustainably manage water availability in the area.