Agenda Item 1b: Endangered Fish Instream Water Rights for the Yampa River

Home Browse Search

Memo to Colorado Water Conservation Board Members From Peter Evans and E.I. 3encsok Date: December 5, 1995 Re: Endangered Fish Instream Water Rights for the Yampa River Page 4 the study period ( The purpose of these adjustments was to bring gage station records during the period to an estimated 1992 level of depletion). ► Presented statistical gage and adjusted gage record results in tabular and graphical formats on an annual, monthly, and daily basis. The 1970 -1992 hydrologic study period was evaluated and it was determined that this period was representative of the 1906 -1992 hydrologic period of record, used by the Bureau of Reclamation in its CRSS modeling efforts. The study relied on existing data and used generalized assumptions on the use of water (maximum for the 1990 -1992) within each river basin to determine the amount of water which would be physically available in the various river sections under current conditions. CWCB Studies: The CWCB staff took information from the LRCWE study and included the findings in a report titled "Yampa River near Maybell, CO and at Deerlodge Park, CO Physical Water Availability Study." This report summarizes the results from the LRCWE study and presented flow duration curves for each month of the year using average daily and average monthly flow data. The report also included flow duration curves and tables for annual volumes and peak flows. This report was first presented to the Board at its September 1994 meeting. Since that time the report has been discussed and revised based on comments from subsequent Board meetings and special Board workshops. Public comments have been taken and revisions have been made. The final version dated November 15, 1995 incorporates the comments from the Board and public. It is the CWCB staff conclusion that the physical water availability studies conducted by LRCWE and by the CWCB indicate that there is water physically available to appropriate for the recommended endangered fish flows. LEGAL WATER AVAILABILITY - 7 Sv To determine the legal availability of water in the Yampa River, the following activities were conducted: The Colorado River Compact Water Development Workgroup Recommendations: The Board informally convened the ad hoc Endangered Fish Flow and Colorado River Compact Water Development Workgroup ( "Workgroup ") to assist the Board in estimating Colorado's unused apportionment of Colorado River water and in evaluating how the unused apportionment could be distributed so endangered fish flow appropriations would not deprive the people of the State of Colorado of the beneficial use of waters available under interstate compacts. The Workgroup consisted of 17 people representing various interests associated with the Colorado River and was first convened on October 28, 1994. Approximately nine public meetings of this group were held to estimate and discuss the future uses of Colorado's unused compact apportionment. Two of these meetings were joint meetings with the Board. The Workgroup provided the CWCB input on how much water could be appropriated for endangered fish recovery instream flows within the various sub -basins of the Colorado River basin in Colorado