Hydrological attributes of terrains (Water Overlay)

Terrains in a project have a number of hydrological properties which can influence the flow of water in a project. Because there is always both surface and underground terrain defined for the entirety of the project area, all cells are affected by all properties of terrains, unless a construction is present with overwriting values.

Attribute	Unit	Type	Description
WATER	boolean	Surface	Whether the specified terrain is a water terrain.
ROOT_DEPTH_M	m	Surface	The depth of the roots of this surface terrain, relative to the surface. Water can be drawn from the underground and evaporated if the roots can reach it.
WATER_EVAPORATION_FACTOR	factor	Surface	How fast this terrain can evaporate water from the underground. The weather evaporation speed is multiplied by this factor to determine the rate of evaporation.
WATER_STORAGE_PERCENTAGE	fraction	Underground	The percentage (as a fraction) of the underground volume which can be filled with water. A lower percentage means the underground will be able to store less water, and the saturated zone will rise higher with the same amount of water in the underground layer.
GROUND_INFILTRATION_MD	m/day	Surface	The speed at which water can flow vertically from the surface to the underground unsaturated zone.
GROUND_INFILTRATION_MD	m/day	Underground	The speed at which water can flow vertically from the underground unsaturated zone to the underground saturated zone, and horizontally through across the saturated zone.
WATER_MANNING	s/(m^1/3)	Surface	The Gauckler–Manning coefficient of the terrain.