A large area in Eastern Hadley Valley is colored grey, indicating no data. Elevation points are not present east of the border between the dark blue and grey, therefore one element of the three-part model is missing. The potential infiltration model recognizes this and identifies as no data.
As pictured, areas of red indicating impervious roads and D soils are still represented as restricted throughout the no data polygons. Values of zero, or restricted variables are set as highest priority in the model.