ICM SWMM and Detention Ponds

ICM SWMM and Detention Ponds

InfoWorks Integrated Catchment Model (ICM) with Storm Water Management Model (SWMM) is a sophisticated software tool used for simulating and managing water quantity and quality in urban catchments. It can model a variety of hydraulic structures, including detention ponds.

Here's a simplified explanation of how you can use ICM SWMM to model a detention pond with a box outfall with weirs and an orifice:

1. Detention Pond: In ICM SWMM, a detention pond can be modeled as a "Storage Unit." The "Storage Curve" feature allows you to define the relationship between the water depth and the storage volume in the pond.

2. Weirs and Orifices: Weirs and orifices are two types of outlet structures often used in detention ponds to control outflow. In ICM SWMM, you can model these using "Outlet" objects. You can define the type of outlet (weir or orifice), the geometry, and the discharge coefficients. If the pond has both a weir and an orifice, you can model these as separate outlets.

3. Box Outfall: An outfall in ICM SWMM represents a point where water exits the system. It can be linked to the detention pond via a conduit. The box shape of the outfall doesn't directly impact the hydraulic simulation, but the dimensions can be used to configure the outfall's capacity.

4. Evaporation: ICM SWMM can model evaporation from the surface of the detention pond. The evaporation rate can be specified in the "Climate" settings of the model. This rate can change over time based on the weather data you input.

5. Side and Bottom Infiltration: Infiltration from the pond to the surrounding ground can be modeled using the "Exfiltration" feature in ICM SWMM. This allows you to set a rate at which water seeps out from the storage unit into the surrounding soil. You can set different rates for the side and bottom surfaces.

While creating your model, you'd need to calibrate and validate it using observed data to ensure its accuracy. This is a high-level overview and actual modeling might require more specific steps based on the unique characteristics of your detention pond and outfall structure.