Chatfield Reservoir was built in 1975 by the U.S. Army Corps of Engineers (Corps) at the confluence of the South Platte River and Plum Creek to control flooding. The reservoir currently has the ability to store more than 350,000 acre-feet (AF) of water.

The main purpose of the reservoir is for flood control, but it also provides storage space for conservation (or multipurpose) water, which is used for municipal, industrial, agricultural and recreational uses, as well as maintaining fisheries and wildlife habitat.

Regional Water Demand

Colorado’s population is projected to increase by 65 percent from 4.34 million in 2000 to 7.16 million in 2030. The Statewide Water Supply Initiative, commissioned by the State Legislature, estimates by 2030, water demand along the Front Range will exceed supply by 22 percent, leaving 90,700 AF of unmet needs. Water users have looked to Chatfield Reservoir as one of the potential solutions to store surface water and reduce their dependency on non-tributary (non-renewable) groundwater.

Chatfield Reservoir Reallocation

In response to the growing demand for water, the U.S. Army Corps of Engineers (Corps) determined Chatfield Reservoir can accommodate an additional 20,600 acre feet of water storage for water supply without compromising its flood control function. This additional storage space will be used by municipal water providers and agricultural organizations to help meet the diverse needs of the state.

On May 29, 2014, the Corps approved the final Feasibility Report/Environmental Impact Statement for the project and the Record of Decision has been signed. This means the Corps has approved the recreation and environmental mitigation efforts identified by the eight Chatfield Project participants and given its blessing to move forward with the project.

Storing more water in Chatfield will raise water levels above their historic operational high level at 5432 feet to a new highest level of 5444 feet, an increase of 12 feet. This rise will impact recreational and environmental features at the water’s edge and the EIS includes numerous mitigation measures to lessen and compensate for these impacts.

Design work is set to begin this year. No additional water will be stored in Chatfield Reservoir until the recreational facilities have been modified to accommodate the increased storage capacity. It is anticipated the construction work will last for 1 1/2 to 2 years. Some parts of the park will stay continuously open through the construction and some features of the park, like campgrounds, will not be affected by the construction.

The Chatfield project participants have been working for more than 10 years with Colorado Parks and Wildlife, Colorado Water Conservation Board, U. S. Army Corps of Engineers, environmental groups and interested citizens to prepare for this project. The project participants want the mitigation work to be done well, with as little impact on visitors as possible.