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What's in the Final Chatfield Reservoir Storage Reallocation Reports?

Published Aug. 16, 2013
Chatfield Dam was the second of three dams built to reduce flooding risks in the Denver area. Located southwest of Denver on the South Platte River, construction of the dam was begun in 1967 and was completed in 1975.

Chatfield Dam was the second of three dams built to reduce flooding risks in the Denver area. Located southwest of Denver on the South Platte River, construction of the dam was begun in 1967 and was completed in 1975.

OMAHA, Neb. - The Final Chatfield Reservoir Storage Reallocation Feasibility Report/Environmental Impact Statement (FR/EIS) was released for public review on August 2. Following the scheduled September 3 close of the public comment period, the U.S. Army Corps of Engineers, Omaha District will prepare a submittal package with a recommended action for the Assistant Secretary of the Army for Civil Works to approve.

The reports outline the feasibility for reallocating storage space from exclusive flood control to joint flood control and conservation purposes within the Chatfield Reservoir in Littleton, Colo. The proposed project would decrease dependency on non-renewal underground aquifers. Because of Chatfield Reservoir’s location high in the watershed, surface water may be captured in the existing Federal facility to help meet a portion of the water supply for the growing population in the Denver area.

The Corps was required to provide an Environmental Impact Statement, which outlines the potential impacts to the environment and existing purpose of the project as well as provide solutions for minimizing or mitigating those impacts.

To address public comments received on the draft report, additional information was added to clarify the varied impacts, mitigation required and to outline responsibilities such as success criteria, monitoring, reporting and oversight for the mitigation to ensure success.

A reservoir fluctuation zone analysis was conducted and added to the report as Appendix HH. The analysis evaluated six Colorado reservoirs similar to Chatfield and it is anticipated that Chatfield Reservoir will continue to provide important wildlife habitat with the expanded fluctuation zone.  An Adaptive Management Plan, Appendix GG, explains a framework for addressing uncertainties for a variety of resources. Tree management proposals are presented in the Compensatory Mitigation Plan, Appendix K. Tree planting and tree protection will provide a mosaic of different ages and sized trees in the Chatfield State Park area mitigating for those inundated and removed to ensure boating safety and reservoir operations.

The project involves many parties voicing an interest including the Colorado Department of Natural Resources, the project sponsor, and water providers as well as representatives from federal, state and local government including nongovernmental groups such as the Sierra Club and Audubon Society.

"We have coordinated extensively with all these groups,” said Gwyn Jarrett, project manager, "They have served as subject matter experts in their specialty areas as the Corps considered the presented alternatives. By working together, the FR/EIS captures and reflects a balance of interests and ultimately proposes the recommended alternative.”

The draft report, published in June 2012, received nearly 1,000 comments from the public that were considered and compiled into Appendix DD of the final report.

Once the public review period for the final Chatfield Reservoir Storage Reallocation Reports is complete, the Corps will submit a final recommendation to the Assistant Secretary of the Army for Civil Works for approval.

"Before a final decision is made, the recommendation will be reviewed to ensure it complies with legal requirements and meets the project’s intended purpose," said Jarrett.


Contact
Gwyn Jarrett
gwyn.m.jarrett@usace.army.mil
or
Omaha District Public Affairs
402-995-2417

Release no. 20130816-001