Border model (Water Overlay)
The outer edge of cells of the water model are excluded from calculations. Due to the way the way a grid is calculated in the Tygron Platform, the edge of the model needs to consist of cells which are inert. No water can flow from or to there.
The edge of excluded cells is at least 1 cell wide, but the width can vary based on the configuration of the method of calculation for the Water Overlay. For example, when QUAD_CELL is enabled, the edge is 2 cells wide due to internal calculations combining properties of multiple cells. The QUAD_CELL technology is by default enabled.