Designing Storm-Water Controls to Promote Sustainable Ecosystems: Science and Application

This paper presents an approach for designing storm-water controls to promote sustainable ecosystems. The approach focuses on understanding and resolving impacts from storm-water discharges on geomorphic stability of stream channels. To develop effective controls, it is critical to understand performance with links to instream hydrology and geomorphology. Comparing work curves and erosion potential in receiving channels between pre- and posturban conditions is the preferred method to test effectiveness and define management criteria. Work incorporates the combined influence of flow, sediment, geometry, slope, and resistance of the channel boundary and can be used to measure the change in erosive energy resulting from urban discharges. Flow duration control can be used to design on-site storm-water controls because flow duration is directly linked to channel processes. Flow duration control also has the potential to “mimic” predevelopment hydrology and be protective of beneficial values. Examples are presented to illustrate the application of work, the erosion potential, and flow duration control as decision making and design criteria.