The simplest approach to defining the hydraulic conductivity (K) of the aquifer is to assign a single, effective value. This is the strategy presented here (22.86 m/d or 75 ft/day). But other options are also available. It is possible to upload a raster file with spatially-varying K; or you can use spatially-variable K data available from the MAGNET Data Center Server. Zone features (polygons) can be added within the model to represent local heterogeneities with a local K value different from the domain K. With zones, you can also use scatter points for spatial interpolation of K, or you can generate a random K field defined by a group of statistical parameters. Adding zones and defining their attributes is covered more in Sections 5 and 6.