Low Impact Development and Rainwater Harvesting

Abstract

Under predevelopment conditions, much of rainwater stayed in the area where it fell, either recharging the underlying shallow aquifer or slowly returning to the atmosphere via evapotranspiration. Land development activities increase the imperviousness of land surfaces, decreasing infiltration and increasing runoff. Traditional stormwater management seeks to collect and remove runoff from sites as quickly as possible with associated downstream impacts of water quality deterioration, erosion, and flooding. Low impact development and green infrastructure methods are intended to mimic predevelopment site hydrology by storing, infiltrating, evaporating, and detaining runoff as close as possible to its source. Rainwater harvesting includes methods that slow the flow of water and increase local infiltration. Low impact development and rainwater harvesting serve to improve water quality through natural contaminant attenuation processes and provide increased, decentralized groundwater recharge. The performance of low impact development and rainwater harvesting systems depends on local hydrogeology and opportunities exists for improved performance such as by the use of soil amendments.