Grouno‐Water Reservoir Operation for Drought Management

Abstract

A hydrodynamic groundwater model is integrated with a multi‐level management model to formulate a composite model for investigating groundwater reservoir operation for drought management. The hydrodynamic model solves the three‐dimensional groundwater flow equation by the finite difference method. A U.S. Geological Survey Model with extensions is used for this purpose. For given hydrogeological conditions, the management model assists the planner to design a system for augmenting low streamflows according to stipulated water supply requirements, by: (1) Arranging the wells within each unit of a multiaquifer system; and (2) establishing the withdrawal pattern for the system. Sensitivity analyses are made of the parameters pertaining to the conjunctive use of water by applying the model to the Mashipacong Island area in the Delaware Basin. The studies consider the hydrogeological properties of the aquifer and streambed, artificial measures to reduce induced infiltration, and arrangements of wells and pumping schedules. Among the infiltration reduction measures studied, a vertical semi‐pervious core extending through the entire thickness of the aquifer can reduce losses from over 60% to less than 40%. Such a cutoff core, constructed by the slurry trenching process, may be economically attractive.