GREEN INFRASTRUCTURE RETROFIT

Under grant funding provided by the New York City Department of Environmental Protection (NYC DEP) and in collaboration with Drexel University, eDesign Dynamics was responsible for the design, construction, and monitoring of two converted rain gardens at the downslope end of the parking lot of the historic Poppenhusen Institute.

Rain gardens, employing an innovative use of sub-surface water storage chambers, were designed to capture a 2-inch rainfall event. This practice of capturing more than NYC DEP’s target 1-inch rainfall volume, pursued in response to the lack of a near enough sewer connection to accept overflow, helped set the precedent for New York City green infrastructure standard design practice for sites having similar conditions. The rain gardens will allow for stormwater to be treated and filtered through biogeochemical mechanisms in the rhizosphere, in addition to demonstrating ecologically and socially valuable methods for controlling stormwater at its source. The design plans also include a comprehensive water quantity monitoring program using tipping buckets, groundwater wells, and piezometers to assess the total precipitation falling on the site during a given event, and the volume of water captured and infiltrated by the green infrastructure.