Managing stormwater more sustainably using green infrastructure and low impact development

As cities continue to develop and densify, there is usually a notable increase in impermeable surface areas. With the introduction of more impermeable surfaces, significantly less rainwater is able to infiltrate back into the ground. When rainwater travels over impermeable surface areas, the runoff picks up toxic pollutants. This polluted water, hereafter referred to as "stormwater", is generally conveyed into storm networks and eventually discharged into receiving outfall areas. When large volumes of polluted stormwater are discharged at high velocities, this can result in the pollution and erosion of receiving areas. As cities continue to grow, and with climate change on the rise, sustainably managing stormwater has become increasingly more important in today's urban environment. Relying only on conventional stormwater management practices can be problematic, since today's stormwater management solutions should be designed to respond to climate change, and the changing urban landscape. Using lesson-drawing and the voluntary transfer of information from the City of Philadelphia, this thesis suggests the use of green infrastructure, and low impact development in order manage rainwater as close to the source as possible. As a guiding principle, this thesis encourages planners, engineers, civil designers, and landowners to build natural processes back into the altered urban environment and use green infrastructure and low impact development whenever possible to manage stormwater more sustainably.