Document Type


Publication Date

January 1977


A joint research effort by the Utah Water Research Laboratory and the Nevado Center for Water Resources Research applied two multiobjective planning models to the Virgin River Basin in order to test the efficiency and practicality of applying such tools in water resrouces planning. The surrogate Worth Trade-off (SWT) method couples mathematical optimization to quantify trade offs among noncommensurable objectives with interviews to compare public preferences with respect to these trade offs. PROPDEMM uses information on interest group objectives, balues, willingness to pay, influence, lebel of information, etc. to compare the political feasibility of alternative courses of action. Both models were applied to assess the difficulties in doing so and the usefulness of the results. The trade offs identified by the SWT method showed agricultural water use to be so dominant in the basin that slight adjustments in irrigation efficiency could supply all foreseeable needs for additional water for other uses, such trade offs to be too inconsequential to identify and compare public preferences, and other trade offs to be impossible because of the position taken by ecologists that any environmental change would destroy a rare species of minnow. Prior to analyzing a situation by the SWT method, the planner should make sure that the trade offs will be of a magnitude meaningful to the public and that the model selected will be sufficiently refined in analyzing small units in time and space to identify locally significant trade offs. PROPDEMM showed the politically most controversial trade off to be between construction of energy generating facilities and life support for the minnow, a controbersy that would probably be decided in favor of the environmentalist because of their power and non-openness to change. Improvements to the model to do a better job of interfacing environmental with social data were recommended. Social modeling in such low population areas was found to be restricted by laws against disclosure of private information because of the very small numbers of individuals living in many evaluation units.