Release no. 17-047
The Corps of Engineers, Omaha District, finalized its Record of Decision (ROD) approving the Windy Gap Firming Project on May 17, 2017. The project is proposed by the Municipal Subdistrict, Northern Colorado Water Conservancy District (Subdistrict) and involves the construction of Windy Gap Firming Project Water Supply facilities for its customers and 13 other Front Range water providers. The Subdistrict requested a Section 404 Clean Water Act (CWA) Permit from the Corps’ Omaha District Denver Regulatory Branch. “Due to the potential for significant environmental impacts to the East and West Slopes of Colorado, this project resulted in the preparation of an Environmental Impact Statement (EIS)” said Kiel Downing, Denver Regulatory Office Chief. The U.S. Bureau of Reclamation (Reclamation) was the lead federal agency preparing the EIS, and the Corps participated as a Cooperating Agency.
The original Windy Gap Project, constructed in the early 1980’s, was intended to provide more than 40,000 acre-feet of firm yield to the east slope, but due to operational constraints that didn’t happen. The project currently captures water from the Colorado River, pumps it to existing reservoirs on the west slope and moves the water through a tunnel system (the Colorado-Big Thompson Project operated by Reclamation) to the Front Range of Colorado. Because of the historic deficiency in water deliveries and lack of storage, the Windy Gap Project participants have not been able to fully rely on existing Windy Gap Project water for meeting a portion of their annual water demand. As a result, the participants, initiated the proposed construction of the Chimney Hollow Reservoir, which would firm all or a portion of their individual Windy Gap Project water allotment units to meet a portion of existing and future municipal and industrial water requirements. The Chimney Hollow Reservoir, as proposed, is a 90,000 AF capacity reservoir that will be dammed at the northern and southern limits.
Reclamation published the Windy Gap Firming Project, Environmental Impact Statement in November of 2011, and ROD on December 12, 2014. The State CWA Section 401 Water Quality Certification began shortly thereafter with the Subdistrict submitting its application to the State in March of 2015. The State issued the Section 401 WQC for the WGFP on March 25, 2016. This determination was necessary for the Corps determination under Section 404 of the CWA. The Subdistrict provided the Corps its Mitigation Plan for permanent and temporary impacts to Waters of the U.S. associated with the WGFP on March 17, 2017 and the Corps with continued agency collaboration, updated study information, and new Federal and State requirements, finalized their ROD shortly thereafter marking the end of the federal approval process.