Zonebudget (ZONBUD) is a computer program that computes subregional water budgets using results from the MODFLOW ground- water flow model. The user designates the subregions by specifying zone numbers. A separate budget is computed for each zone. The budget for a zone includes a component of flow between each adjacent zone.
Harbaugh, A.W., 1990, A computer program for calculating subregional water budgets using results from the U.S. Geological Survey modular three-dimensional ground-water flow model: U.S. Geological Survey Open-File Report 90-392, 46 p., https://doi.org/10.3133/ofr90392