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, ~r. Richard L. Drown , -0- Februa ry 17, 1976 6~~y:r IX - f\lternatives Further ground viater development is discussed as an alternative to the Narrows Reservoir for providing supplemental water but is stated to be infeasible under present legislation. This is not correct because it is possible to utilize additional ground water vlith existing l'lells by initiating progrilms to recharge the alluvium \'Ii th excess surface \'Iater. A demonstration project is present1y undenvay on the South Platte Ditch near Prewitt Reservoir to demon- strate the feasibility of artificially recharging the alluvium with surp1us stream flows. The results from the first year of operation have been published and are available at this office. It appears that artificial recharge is quite feasible and provides supplemental water at a relatively low cost. The Held County site is discussed in a fairly detailed Illanner since considerable data has been generated especially since 1961. The Vie 1 d Coun ty site has a hlays been a mo re expens i ve site than the Na rrOl'iS site because of des i gn criteri a es tab 1 i shed by the Bureau and the lack of suitable illlpervious material neilI' the dam. The difference WilS approximately 50 per cent ($23,646,000) in 1964 when the Narrows site was selected. It is stated (page IX-25) that a new study of the Weld County site was conducted in December 1974 and July 1975 to make a current comparison with the Narrows site. The results of the study indicated that the Weld County site was still 50 per cent higher; however, these studies were not included as an appendix to t.lle Environmental Statement so that these studies could be utilized. .., From other points of view, it would appear that the Held County site is better, such as the number of people to be relocated, the quality of irrigated lands to be removed from production, the impact upon existing wildfowl areas, the yield of salable water to the project, and the increase in divertable return flows. As an example, it stated on page IX-16 that the Riverside and Empire Reservoirs would be included in the project and converted to wildlife IlIarsh habitat. The reason fOt' this ilction is not given nQr discussed. The utilization of project, water supplies to sustain these Ciurshes \'Jhich have high evaporation losses does not appear to be a prudent use of a scarce resource. If the Riverside and Empire Reservoirs water storJge rights are transFerred to the Weld County Heservuir, the projr~ct ,hller supply vlOlIld be incr0.ased by the sav'ings in his tOI'ic eVilporution and seepuge losses. Also, the !iureau's design cl'ileria for the l'leld County site includes a positive cutoFf below the dam to bedrock. This positive cutoff will result in vel'y little seerage under the dam and Ivollld increase the project's salable l'later supply as compared to the Narrows site \'Ihich has the potential for very high losses. The reservoir opel"ation study used