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IN REPLY REfER TO, 565. 720 . . United States Department of the Interior --OOREAl::J-Bf-REEtAt\'h\Tf0N- WATER AND POlmR RESOURCES SERVICE SOUTHWEST REGION .714 S. TYLER AMARILLO, TEXAS 79101 - jUL 1 0 1980 F~E~JI J U L 1 4 1980 , c. COLO. WA-TER CONSERVATION BOARD Memorandum To: Regional Director, Region 6, U.S. Fish and wildlife Service, Lakewood, CO 80225 From:'~ Regional Director Subject: Results or Mitigation Meeting on June 10, 1980--Closed Basin Division, San Luis Valley Project, Colorado Enclosed are lists of representatives invited to and those attending the subject meeting. By copy of this memorandum, agency representatives invited to the meeting ate being apprised of the results. I view the meeting as being productive. The meeting agenda suggested in my memorandum qf May 29, 1980, was generally followed, excluding items Nos. 8 and 9, mitigation determinations. The morning session of the meeting mainly was devoted to presentations of current data analyses. Water and Power Resources Service (Water and P.ower) personnel described the extent of surface water across the project division area during the spring .through fall period of 1979. A series of' aerial photographs shows that the maximum surface water area during this period aggregates a total of about 4,000 acres within the project division. In presenting analysis results of the summer 1979 wetlands data (data package mailed March 14-17 to various agencies), Water and Power personnel indicated the lack of obvious correlations between infiltration rates and wetland types. The U.S. Geological Survey (USGS) representative explained the results of current water quality analyses and two- dimensional aquifer modeling] including a predlctive water table drawdown map. Discussions in both the morning and afternoon sessions were prompted by the USGS representative's mention of estitnated pumpage source amounts used in modeling. These discussions concerned the implication that after 54 years of project divi- sion operations, about 75 percent of the pump age would consist of leakage from the confined aquifer. This 75 percent value was later (June 24) confirmed by the USGS representative to be the pumpage presently assigned in the aquifer model to evapotranspiration from the unconfined' aquifer, rather than to leakage from the confined aquifer, The results of the Fish and Wildlife' Service National Wetlands Inventory of 43,441 acres of total wetlands within the project division (1975 aerial photography) were compared to previous wetlands inventories. Wetland types and potential relationships to. water table levels were discussed. .