Utilization of Emerging Geo-Spatial Technologies in the Implementation of Conjunctive Management of Surface and Ground Water in the Boise River Basin

Abstract

Historically the delivery of water rights in the Boise River Basin in the State of Idaho has focused on flows in the Boise River proper. Water District 63 has for decades employed a Watermaster who has measured diversions from the river, and who has curtailed these diversions on a priority basis. Wells located near the river have never been considered to be part of the delivery system, even when delivery of pre-1900 water rights from the river is curtailed. Creation of conjunctive management rules in Idaho, and a growing awareness of the relationship between surface and ground water systems, have led regulators to consider the impacts of the diversion of ground water that is tributary to the Boise River upstream from and within the regulated reaches of the river. Proper and equitable long-term delivery of this ground water mandates that delivery be monitored in conjunction with Water District 63. Researchers are assembling data and technical analyses that will enhance the capability to determine the interconnectedness and flow patterns of ground water throughout the basin. More than 100 distinct GIS data layers have been assembled. However, a difficult question that remains is how these data and analyses will enable decision-making and implementation of decisions relative to ground water pumpage at specific locations throughout the basin. This paper proposes a methodology to conduct a one-day collaborative spatial decision-making session to be attended by the significant stakeholders relative to conjunctive management within the basin, including irrigators, municipalities, government and environmental representatives. The paper details a technique whereby commercially available software such as GeoChoicePerspectivesTM is used to assist the stakeholders in developing a conjunctive management implementation plan. The stakeholder session will utilize a Collaborative Spatial Decision Making (CDSM) approach to identify the significant variables and to derive an optimal process for determining the extent of allowable pumping at wells in the basin. The effectiveness, of the CSDM process will be compared against the effectiveness of a control group that uses conventional maps and charts. The stakeholder sessions are scheduled for May 2001, and the results of the sessions are anticipated to be reported at the 2001 Specialty Symposium on Integrated Surface and Ground Water Management.