Model attributes (Water Overlay)

The Water Overlay's model calculations depend on a number of calculation-wide parameters. These parameters are available as attributes of the water overlay and can be modified as such.

Attribute	Unit	Range	Description	Default value
ALLOWED_WATER_INCREASE_M	m		The amount by which the water level on a water terrain must increase before it is considered stressed by water. This is used to compute the WATER_STRESS result type.	0.4
CULVERT_DEM_THRESHOLD_M	m	0 to 10000	The maximum distance a culvert's height can be below the terrain, for the terrain height to be adjusted to the threshold of the culvert.	10
DESIGN_FLOOD_ELEVATION_M	m		Buildings in the model are assumed to have at most this height compared to the surface of the terrain. Greater values can create a more accurate model but will impact performance.	1
GROUND_BOTTOM_DISTANCE_M	m	0 to 10000	Assumed distance under the surface terrain where the bottom boundary is situated.	10
GROUND_WATER	nominal value		Whether and how water in the ground is simulated during the calculation.	Infiltration Only
GROUND_WATERTABLE_WITH_SURFACE	boolean		Whether the ground watertable result type should also include the surface water level, when the groundwater levels are close to the surface.	True
IMPACT_FLOOD_THRESHOLD_M	m		The amount of water a Building must experience before it is considered impacted by water.	0,1
IMPACT_RANGE_M	m		the width in meters of the water next to or against the building that have to be flooded before the building is considered impacted by water.	3
BRIDGE_ELEVATION	nominal	0 to 2	Specifies the mode by which bridges are include in the elevation model, used for the water calculations.	Lowest
INCREASED_RESOLUTION	boolean		Load the DEM at twice the resolution.	False
LIMIT_AREA	boolean		Whether calculations should occur in this area or not.	n/a
LIMIT_RAIN	nominal value		Whether rainfall can be overridden by rainfall defined in rain areas across the project area.	0 (Entire map)
MAX_WATER_BOTTOM_M	m + datum		The maximum height for the bottoms of water terrains. Any water terrain with a bottom at a higher datum height has its bottom lowered to this value.	10000
OBJECT_ENTRY_CORRECTION	cells	0 to 3 cells	How many cells allowed to move a hydraulic structure's entry point when it overlaps with another hydraulic building.	2
SEWER_OVERFLOW_THRESHOLD	fraction (m/m)	0 to 1	How much of a sewer's storage must be filled with water before the sewer overflows are allowed to overflow water.	0.9
SHORELINE	boolean		Whether to automatically fill cells near a water terrain when there is a mismatch between the extend of the water terrain and the DEM.	True
SHOW_DURATION_FLOOD_LEVEL_M	m	-10000 to 10000	The amount of water which must be exceeded in a specific location before the duration of surface water can be recorded. This is used to compute the SURFACE_DURATION result type.	0
SURFACE_WATER_EVAPORATION_FACTOR	factor	0 to 10	The factor by which the weather evaporation factor is multiplied to compute the amount of evaporation which takes place on the surface.	1.3
SURFACE_WATER	Nominal value		Whether and how water on the surface is simulated during the calculation.	Shallow
TIMEFRAMES	integer	1 to 1000	The number of intermediate results recorded during the calculation. Each timeframe becomes a snapshot of data which can be viewed and analysed.	10