External area (Water Overlay)

Icon	Key	Unit	Range	Description	Default value
	EXTERNAL_AREA	m²		The surface area of the external water body behind the breach. The larger the external water body, the more water can flow from it (or into it), and the smaller the effect of the inflow or outflow of water on the external water level. When provided with a second value, this key will also define a bottom area for the external water body, transforming its cross-section from a rectangle to a trapezoid.	n/a

Notes

When two values are set for this key, the first value will represent the surface area of the external water body and the second value will represent the bottom area of the external water body. The water body will be interpreted as a trapezoidal prism, with a length set to the square root of the surface area. This will cause the water level of the external water body to change at a non linear rate.
When a breach input area is defined, an external water body will not be created. Subsequently, the EXTERNAL_SURFACE_LEVEL, EXTERNAL_WATER_LEVEL and EXTERNAL_AREA attributes will be ignored.