Drainage datum (Water Overlay)

Icon	Key	Unit	Range	Description	Default value
	DRAINAGE_DATUM	datum	-10000 to 10000	The datum height (int meters) of the drainage.	-10000

Water can be drained out of the underground when it exceeds the drainage's datum height. Water in the underground lower than the drainage is out of reach, and cannot flow through the drainage.

Notes

• The drainage height should be higher than the bottom of the waterway it can drain water to.
• If no height is defined, the drainage is considered to be low enough for all groundwater to flow into the waterway.
• If no height attribute is defined, a DRAINAGE_OVERFLOW_THRESHOLD must be defined, otherwise the assumed low positioning of the drainage will prohibit surface water from flowing in or out.
  • This means that the height attribute is required when using passive drainage, otherwise water will never be able to flow through to the drainage lying far below the surface.

See also

• Drainage (Water Overlay)
• Drainage overflow threshold (Water Overlay)

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Water Module

Water Module

Tutorials

Overview

Theory

Benchmarks

Group

Hydraulic structures

Inlet

Inlet q • Inlet area • Inlet capacity •  Lower threshold •  Upper threshold • Inlet underground

Pump

Pump q •  Lower threshold •  Upper threshold • Pump angle • Pump capacity • Pump area

Culvert

Culvert diameter • Culvert rectangular height • Culvert threshold • Culvert n

Weir

Weir height • Weir width • Weir angle • Weir coefficient • Weir n • Weir target level

Sewer overflow

Sewer overflow • Sewer overflow speed

Drainage

Drainage q • Drainage datum • Drainage active • Drainage overflow threshold

Output

Object flow output • Object height output • Object datum output a • Object datum output b • Object water area output • Object width output • Weir dam output

Related

Building attributes • Hydrological features •  Terrain attributes • Model attributes • Results • Simulation data