Stormwater Management/BMP's

AMT provides stormwater management planning and design services to our clients. Stormwater planning begins with GIS mapping to help determine treatment options to consider, taking into account proximity to wetlands and streams, existing watershed land cover (vegetation and habitat), water sources (groundwater, surface water urban run‐off, tidal ebb and flow, etc.), soils and geology, topography/slopes, property ownership, construction feasibility and access issues, utility issues, property ownership, and other stakeholder issues.

Stormwater management can include Low Impact Development (LID) and Green Stormwater Infrastructure (GSI) for a modern approach to managing rainfall at the source. The underlying goal is to mimic a site’s pre‐development hydrology by using design techniques that infiltrate, filter, store, evaporate and detain runoff. Stormwater management solutions also include a wide range of other BMP types including dry detention, wet ponds, pre‐manufactured treatment devices, and many others.

For stormwater management design, AMT prepares drainage area mapping and hydrology estimates for peak discharges under existing, proposed and/or ultimate conditions using TR‐20, TR-55, HydroCAD, SWMM and other software tools. Stormwater storage values are then determined based upon water quality treatment requirements tied to imperviousness of the project area, as well as water quantity treatment requirements tied to adequacy of the downstream channels and the avoidance of increased discharges. Designs are often a collaboration between environmental planners, landscape architects and a variety of engineers to provide the best “bang for your buck” with an eye towards long-term maintenance.