The US Bureau of Reclamation and the Northern Colorado Water Conservancy District plan to upgrade the Horsetooth reservoir’s four earthen dams to control water seepage. The reservoir, located west of Fort Collins, stores water for household, commercial and agricultural use in northern Colorado, US. The plan for the repair was proposed after a three-year study of increased leakage at the reservoir’s north dam. News of increased leakage has caused concern around the City of Fort Collins, as a dam failure could cause devastating flood damage.

Project design was scheduled to begin in January 2000, with construction possibly starting later on in the year. It is expected the repair will involve stripping of material from the downstream side of the 50-year-old dams; adding filters of fine sand and rock at the base of the dams; replacing the outer shell of dirt and rock; and thickening and buttressing key sections. The dams have clay cores that do not require any alteration.

Horsetooth reservoir is a vital part of the Colorado-Big Thompson project, northern Colorado’s major water distribution system and the state’s largest transmountain water-diversion project. The US Bureau of Reclamation owns the project, and the Northern Colorado Water Conservancy District operates and maintains the project with the Bureau.

The project carries water from the headwaters of the Colorado river across the Continental Divide, delivering it to 30 municipalities and a number of agricultural users.