Consideration of Administrative Management Constraints in the Development of Groundwater Supply Strategies

Utilization of groundwater from many aquifers across the semi-arid west is managed or regulated according to some form of a managed depletion approach, typically implemented through allowable rates of drawdown through time. New appropriations or transfers of water rights in such basins are often evaluated according to the ability of the appropriator to meet administrative basin depletion criteria, which leads to the challenge of balancing aquifer withdrawals required for development against administrative or legal constraints. Simulation-optimization tools are well-suited for assessing or identifying favorable water development strategies and approaches, since they can objectively incorporate multiple, potentially complex constraints into the decision making process.

A case study will be presented where a simulation-optimization approach was used to identify favorable groundwater diversion strategies subject to groundwater basin depletion constraints. The simulation model used is an administrative groundwater flow model developed for a groundwater basin in New Mexico. The optimization program applied is GWM, the ground water management program recently developed for MODFLOW-2000. The objective was to identify maximum well field yield subject to well production limitations, allowable administrative drawdown constraints, and well location limitations. Some key uncertainties and challenges associated with using optimization-based approaches as management tools will also be considered.