Windy Gap Firming Project. Lake and Reservoir Water Quality Technical Report.

摘要

The Bureau of Reclamation (Reclamation) has received a proposal from the Municipal Subdistrict, Northern Colorado Water Conservancy District, acting by and through the Windy Gap Firming Project Water Activity Enterprise (Subdistrict) to improve the firm yield from the existing Windy Gap Project water supply by constructing the Windy Gap Firming Project (WGFP). The proposal includes a connection of WGFP facilities to the Colorado-Big Thompson Project. For more information on the background and purpose of the WGFP, see the Windy Gap Firming Project Purpose and Need Report (ERO, 2005a). This technical report was prepared to address the potential environmental effects on lake and reservoir water quality associated with the alternatives described below and will be used in the preparation of the EIS. Surface and ground water resources and ground water quality are addressed in the Water Resource Technical Report (ERO and Boyle 2007). Stream water quality is described in ERO and AMEC, 2008. The Windy Gap Firming Project alternatives that are being evaluated in the EIS are described in Section 2. Section 3 provides a description of the reservoirs that may be affected by the Project alternatives. The objectives of this technical report are described in Section 4. Data obtained and used for the completion of this report are described in Section 5. Section 6 provides a discussion of federal, state, and local water-quality regulations. Concepts of trophic status and the eutrophication process are described in Section 7. Section 8 provides a description of the potentially affected environment, which summarizes the existing water quality of the west and east slope lakes and reservoirs that could be affected by the WGFP alternatives. A summary of regulatory water-quality issues is located in Section 9 and the methods used for analysis are described in Section 10. Section 11 provides an analysis of the direct effects of the WGFP alternatives on the lakes and reservoirs described in previous sections and Section 12 provides an analysis of cumulative effects on these reservoirs.