OMAHA, Neb. - The Assistant Secretary of the Army for Civil Works, Jo-Ellen Darcy, approved the Chatfield Reservoir, Colorado, Storage Reallocation Project in a Record of Decision sent to the Omaha District on May 29.
In the accompanying memo, Darcy said, “The proposed reallocation project alternative is technically sound, environmentally acceptable and economically justified.”
The Omaha District released the final Feasibility Report and Environmental Impact Statement (FR/EIS) in July 2013, regarding the request from the Colorado Department of Natural Resources to evaluate using Chatfield Reservoir as a solution for meeting future Front Range water needs while balancing the health of Colorado’s rivers and streams.
Gwyn Jarrett, project manager said, “The Corps has worked with the Department of Natural Resources' Water Conservation Board in Colorado, 15 water use districts, multiple interested stakeholders and non-governmental organizations, including environmental groups, through a highly collaborative process, which helped lead to the approval of this complex, comprehensive project.”
The feasibility report and environmental impact statement aligns with the guidelines of the National Environmental Policy Act, to ensure public input plays a major role in the decision making process and that impacts to wildlife, vegetation, ecosystems, water and air quality, flood control, cultural resources and other factors are properly mitigated.
The U.S. Army Corps of Engineers Director of Civil Works, Steven L. Stockton, requested approval of the FR/EIS earlier this year. In his request, Stockton included an addendum to the report, which provides an update to project costs for Fiscal Year 2014, as well as a summary of public and agency comments on the Final FR/EIS, completed biological opinions related to the South Platte River and the Preble’s Meadow Jumping Mouse, and the finalized Fish and Wildlife Coordination Act Report.
On learning of the Record of Decision, Jarrett said, “The Corps worked with many outstanding agency and organization representatives on this project to assist the State of Colorado in meeting a portion of its growing water demand.”
The project will allocate 20,600 acre feet of storage in Chatfield Reservoir for municipal and industrial water supply and other purposes including agriculture, environmental restoration, and recreation and fishery habitat protection and enhancement.
By reallocating storage from the exclusive flood control pool into a joint conservation/flood control pool, the conservation pool level at Chatfield will increase by 12 feet, and provide an average of 8,539 acre feet of water per year for municipal and industrial use at less cost than other water supply alternatives.
Implementation of the pool rise and use of the reallocated storage will occur incrementally as recreational and environmental mitigation projects are completed. The reservoir operations plan will also be modified to reflect the changes.
In addition to water supply benefits, the FR/EIS states that flood control capabilities at Chatfield and within the Tri-Lakes system will not be affected. The pool raise and more frequent fluctuations in pool elevations will require significant modifications to relocate and replace existing recreation facilities, resources and project roads with new facilities and roads.
The plan includes expansive environmental mitigation to replace or compensate for habitat on Chatfield project lands inundated by the pool raise, including wetlands, bird habitat and habitat (including designated critical habitat) of the federally threatened Preble's meadow jumping mouse. The selected plan includes up to five years of monitoring the environmental mitigation features and adaptive management to ensure mitigation success.
Associated costs including the updated cost of storage, water supply infrastructure, recreation area modifications and environmental mitigation will be funded at no cost to the Federal government.