Rooftop Disconnection LID Control in InfoSWMM and #SWMM5 for Sustain
This is an introduction along with images of the LID Control and data require3ments in InfoSWMM. Every InfoSWMM Control uses from one to 5 layers of data – each with different data requirements. You can use the Siting Manger of InfoSWMM Sustain to find LID locations and the LID Optimizer to find the optimized number of units, cost of units, area and thickness of the LID layers based on your runoff and water quality control objectives.
Rooftop Disconnection has two process layers: (1) Surface and (2) Roof Drain
LID controls are represented by a combination of vertical layers whose properties are defined on a per-unit-area basis. This allows LIDs of the same design but differing areal coverage to easily be placed within different Subcatchments in a study area.
During a simulation SWMM performs a moisture balance that keeps track of how much water moves between and is stored within each LID layer. As an example, the layers used to model a bio-retention cell and the flow pathways between them are shown below:
The following table indicates which combination of layers applies to each type of LID (x means required, o means optional):
|LID Type||Surface||Pavement||Soil||Storage||Drain||Drainage Mat|
When a user adds a specific type of LID control object to a InfoSWMM project the LID Control Editor is used to set the design properties of each relevant layer (such as thickness, void volume, hydraulic conductivity, drain characteristics, etc.). These LID objects can then be placed within selected Subcatchments at any desired sizing (or areal coverage) by editing the Subcatchment’s LID Controls property.
The Roof Drain Process Layer of the RoofTop Disconnection consists of:
· Flow Capacity (inches/hour or millimeters/hour)
The two layers used in a simulation for a Rooftop Disconnection LID are shown in the following image.