Final Report, Efficient and Equitable Solution of Indian Reserved Rights, USGS Grant #14-08-0001-G1320, June 21, 1989. / The water rights claims of many Indian reservations in the West are now under adjudication. Frequently, the parties to these adjudications acknowledge that their interests may be better served through negotiated settlements, but they lack comprehensive means for determining mutually acceptable solutions to the conflicts. The research conducted under the title of "Efficient and Equitable Solution of Indian Reserved Rights" (Project #14-08-0001-G1320) sought to 1) develop a conceptual basis for determining Indian water rights; 2) develop an analytical procedure to provide the information needed to resolve water rights conflicts; and 3) apply this analytical procedure to a test case involving the Gila River Basin in Arizona. The methodological core of the research is a set of linked models, encompassing historical, hydrologic, economic, psychological, and institutional elements of the conflict. Hydrologic, institutional, and economic analyses of conjunctive management of surface and groundwater supplies were facilitated by the use of MODSIM, a network optimization model. Data from the model enabled the investigators to construct an impact matrix, defining the effect of each possible settlement option on the goals of the parties. The preferences of the parties were elicited through social judgement analysis. Twelve settlement options were defined on the basis of knowledge of other negotiated settlements, and a final option, representing possible outcomes should the negotiation process fail, was included in the analysis. The next step was to model the possible choices available the contending parties, utilizing an n-person cooperative game framework. This analysis indicated that a set of three settlement options dominated the adjudication option for all players. Each of these included the provision of imported water in lieu of water currently being used in the basin. It is anticipated that the results of this research will be developed as a book-length manuscript by the principal investigators and the research team.