Green Infrastructure Implementation in Urban Parks for Stormwater Management

Abstract

A newly constructed rain garden in Shoelace Park in Bronx, New York, USA, was monitored between October 2014 and July 2015 as a pilot study aimed at testing the effectiveness of using urban park space to manage adjacent street runoff. Street inlet capture efficiency and rain garden retention were assessed through inflow and outflow monitoring and quantification. During the monitoring campaign consisting of 26 storms, the rain garden retained an average of 78% of all inflows, with full retention for storms under 10 mm (65% of monitored storms). New York City (NYC) is 72% impervious and 19.5% parkland in surface area. If only 4% of NYC parkland space were retrofitted with green infrastructure performing similarly to the Shoelace Park rain garden, the municipal goal of managing runoff from 10% of combined sewer-served impervious surfaces could be achieved, at least at the municipal scale. Additional spatial analyses are needed to determine whether potential parks are positioned ideally for stormwater capture given the variable conveyance capacities of the city’s many combined sewersheds, and the desired pollutant load reductions for each of its receiving water bodies. As suitable right-of-way GI sites become rarer, parklands represent a new exciting opportunity for expanding the extent of distributed stormwater management in cities.