Public Works Stormwater Summit (Day One): Green Infrastructure Solutions for Stormwater Management

This presentation will cover case studies about practical Green Infrastructure applications. Discover what's working and how you will be able to adapt these approaches to your area and systems. Stormwater Quality Retrofits Made Practical Comparing and choosing stormwater quality retrofit alternatives and strategies are challenging. Representatives from the City of Eugene, Oregon, will discuss the benefits and challenges of different water quality alternatives which include rain gardens, large neighborhood-scale swales, and pervious concrete pavement. The City of Eugene is an NPDES Phase I permit holder with years of experience implementing stormwater quality improvement retrofit projects. They'll share the lessons learned and innovative solutions. Town Creek Culvert – Green Infrastructure in the Urban Core Stormwater projects have not traditionally been a major component of the Clean Water State Revolving Fund (CWSRF) awards, but the City of Greenville, North Carolina, successfully obtained a grant for the Town Creek Culvert project by including green infrastructure components. The routing of this culvert through the urban core of the city is also being impacted by the construction of a highway that is adding 45 acres to the culvert's watershed. The culvert will discharge into a regenerative stormwater conveyance (RSC) that will remove nutrients as well as reduce velocities. Other green infrastructure features include a bioretention area upstream from the RSC, a permeable paver system, wetlands, tree boxes, and another smaller RSC. Detention Basin Retrofits for Stormwater Quality Treatment The City of Springfield, Missouri, has embarked on an innovative and unprecedented integrated plan to prioritize future environmental programs. One of the goals of the integrated plan is to find relatively low costs methods of improving water quality in area streams. Most of the existing stormwater detention basins in Springfield, as well as most communities in the Midwest, were designed with the single purpose of providing flood control. A total of 178 existing detention basins are evaluated for retrofit feasibility considering two options: 1) downsizing the outlet structure to achieve additional water quality treatment; 2) downsizing the outlet structure to improve the infiltration rate of the basin and adding a vegetative component. Conventional stormwater best management practices (BMPs) have been commonly applied in Florida since the early 1980s. However, with the realization that conventional BMPs do not always achieve the desired pollutant load reduction, coupled with the need for practices that are better suited for smaller spaces and retrofits in highly urbanized areas, GI/LID practices were added to the BMP palette. Challenges met and overcome included accommodating these practices into the existing regulatory/permitting process and adapting them to local hydrologic conditions. Learning Objectives: Identify stormwater retrofit alternatives and strategies. Describe green infrastructure practices that are useful in pollutant load reduction. Determine which green infrastructure approaches would best fit your local hydrologic conditions.