Low Impact Development for Stormwater Quantity and Quality

Low impact development, also known as LID, is an innovative stormwater management approach modeled after nature. This chapter provides information and case studies on the use of standards to model and design sustainable stormwater LID measures. Modeling requirements and various models that can be used to analyze and design LID measures are described. The benefits of LID measures for effective stormwater management are demonstrated using examples. The chapter also provides information on the latest sustainable design standards for urban stormwater management and construction of green stormwater infrastructure. A Washington, D.C., case study is presented to illustrate the implementation of these design standards. Modeling results that quantify the LID benefits in terms of stormwater quantity and quality are presented. The chapter includes an example of using USEPA's (2009) Storm Water Management Model (SWMM) to quantify the stormwater quantity and quality benefits of a rain garden bioretention system. Introduction A sustainable stormwater management approach keeps more water in the environment, minimizes hydrological disruption of watersheds, and utilizes reuse and reclamation components. Using the concept of decentralized systems, it incorporates small-scale technologies for local treatment and closed-loop systems that reuse water for nonpotable uses, such as toilet flushing, irrigation, an