Temporary ponding is a short lived flood situation, which, in some circumstances, can be tolerated allowing an intentionally undersized trench drain system. It allows a more economical system to be used that will work effectively under most weather conditions, but will be slightly under designed for heavy storms.

Ponding analysis should only be considered where buildings and property are not in close proximity to the drainage system to minimize risk of damage. It is an ideal option for the outer areas of large parking lots, distribution yards, etc., (Risk Analysis).

The ponding analysis map shows the size and duration of the flood.

In order to produce a ponding analysis, the following information is required:

	Information as required to run ponding analysis, including:- Length of trench run (feet or meters) Length and width of catchment area (feet or meters) Surrounding pavement/surface type, e.g., concrete, asphalt, etc. Rainfall intensity (in/hr or mm/hr) Ground fall along trench (%) Perpendicular approach slopes to trench (%) Preferred position of outlets along trench and any outlet size restrictions Any slab depth restrictions
	Plan of site showing elevations
	Existence of any buildings
Results provided are:
	Plot showing extent of ponding
	Average duration of ponding
To request this service, click here.