LID Utilization

Utilizing LID controls within a GeoSWMM project is a two-phase process that:

1.     Creates a set of scale-independent LID controls that can be deployed throughout the study area,

2.     Assigns any desired mix and sizing of these controls to selected subcatchments.

Bear in mind that when LIDs are added to a subcatchment, the subcatchment’s Area property is the total area of the subcatchment (both non-LID and LID portions) while the Percent Imperviousness and Width parameters apply only to the non-LID portion of the subcatchment.

To implement the first phase, one selects the Hydrology | LID Controls category from the GeoSWMM object panel to add, edit , delete individual LID control objects. The LID Control Editor is used to edit the properties of the various component layers that comprise each LID control object.

For the second phase, for each subcatchment that will utilize LIDs, one selects the LID Controls property in the subcatchment’s Property Editor to launch the LID Group Editor. This editor is used to add or delete individual LID controls from the subcatchment. For each control added the LID Usage Editor is used to specify the size of the control and what fraction of the subcatchment’s impervious area it captures.