Discussion of an Ecosystem Functional Basis for Protecting Receiving Waters

This paper is intended to provoke thinking about the efficacy of current technology and the need for new tools to meet one of our more challenging objectives of protecting the ecological integrity of our receiving waters. Included is a discussion of the limits of our current technology and some basic philosophical and scientific principles of a new emerging ecosystem-based approach to the protection of receiving waters. This new approach has evolved from the development, use and study of Low Impact Development (LID) decentralized stormwater management technologies. The primary goal of LID (for new urban development) is to mimic the predevelopment hydrologic regime to better protect streams from hydrodynamic stresses universally associated with urbanization. To mimic the predevelopment hydrology requires a much more thorough understanding of hydrologic / ecological processes at work within each unique watershed and the complex interrelationships of the terrestrial and aquatic ecosystems. The process of urbanizing (or any land use change) essentially destroys, disrupts, and diminishes the capacity of the terrestrial ecosystem to detain, store, evaporate, infiltrate and cleanse runoff. The adverse impacts of urbanization are not absolute or inevitable but are a consequence of the poor state of our technology, the manner in which we choose to handle runoff and the lack of understanding about ecological design and landscape / aquatic ecology.