Towards More Accurate Leakage and Conjunctive Use Simulations:
A Coupled GFLOW-MODFLOW Application

Daniel Feinstein1, Henk Haitjema2, Randy Hunt3

1 USGS, Wisconsin Water Science Center, dtfeinst@usgs.gov, Milwaukee, WI, USA
2 Indiana University, haitjema@indiana.edu, Bloomington, IN, USA
3 USGS, Wisconsin Water Science Center, rjhunt@usgs.gov, Middleton, WI, USA

ABSTRACT

There is a need to develop regional models that are capable of addressing local-scale sustainability issues that typically involve the effect of pumping on baseflow to water bodies. Techniques such as inset models using mesh refinement and stream and lake packages provide one way to leverage regional models to address local questions. We propose an alternative approach of coupling the analytic element code GFLOW and MODFLOW2000 that, while preserving the interplay of shallow and deep stresses, facilitates representation of ground-water/surface-water interactions and conjunctive use without requiring grid rediscretization or use of additional MODFLOW packages.