# Hydrological attributes of constructions (Water Overlay)

Besides the constructions which directly influence the hydrologic model as a hydraulic structure, each construction may also have attributes which can contribute to the hydrological model in some way. These attributes are stored and used on a grid cell level. This is different from the hydraulic structure attributes, which are stored and used on an object level.

These attributes can be changed individually per construction or per construction's function. In most cases, these attributes already exist as a function value. Note that attributes which are connected to a function value can not be redefined using a different attribute name.

Icon Attribute Unit Function value Description
GROUND_INFILTRATION_MD m/day Ground infiltration per day (m) The speed at which water can flow vertically from the surface to the underground unsaturated zone.
SEWERED boolean Connected to sewer Whether this construction is connected to the sewer.
WATER_STORAGE m³/m² Water storage (m³/m²) How much water this construction can store.
ROOT_DEPTH_M m Depth of plant roots (m) The depth of the roots of this construction, relative to the terrain height at the location of this construction. Water can be drawn from the underground and evaporated if the roots can reach it.
WATER_EVAPORATION_FACTOR factor Water evaporation How fast this construction can evaporate water from the underground. The weather's evaporation speed is multiplied by this factor to determine the rate of evaporation.
FLOOR_HEIGHT_M m Floor height (m) The height of a floor in a construction. Additionally each section of a construction can have a different amount of floors.
CRITICAL_INFRASTRUCTURE nominal integer Critical infrastructure Whether this construction is deemed a critical construction. 0 means the construction is never deemed impacted.
WATER_MANNING s/(m1/3) Surface The Gauckler–Manning coefficient of the construction.
SUBSTANCE_A x/m²s The amount of substance A created per second per m² in this location.
SUBSTANCE_B x/m²s The amount of substance B created per second per m² in this location.
SUBSTANCE_C x/m²s The amount of substance C created per second per m² in this location.
SUBSTANCE_D x/m²s The amount of substance D created per second per m² in this location.