Updated Models
GV4 contains the latest versions of MODFLOW2000 (V1.12 at time of release), MT3DMS (V4.50 at time of release) and RT3D (V2.5 at time of release).

Multi-Layer Well Package (MNW)
GV has always supported MODFLOW-SURFACT’s Fracture Well. You can now also use the USGS version of the fracture well called the Multi-Node Well (MNW) Package. This package is available in MODFLOW96 and MODFLOW2000.

RT3D V2.5
GV now supports the new version of RT3D.

Improved Stream Support
GV now allows you to digitize streams and import them from ArcView Shapefiles. GV also has a command to error-check stream boundaries to make sure that they are numbered correctly. This can save a lot of time when using this complex boundary condition.

Better PEST-ASP Support
Pest-ASP is now in the public domain and is fully supported by Groundwater Vistas. This includes the use of pilot points, regularization, predictive analysis, and calibration-constrained Monte Carlo simulations.

MODFLOW96 Double Precision
We have added another version of MODFLOW to our collection of Windows models. The new model is a standard MODFLOW96 (including the LMG Solver and MNW Package) running in double precision. We added this version because most modelers are still relying on the older MODFLOW96 over MODFLOW2000 and because models are getting much bigger and more nonlinear. Under these circumstances, a double-precision version of MODFLOW will converge much better than a single-precision version.