Stream Daylighting as a Strategy for CSO Mitigation – Saving Money and Reducing Overflows by Bringing Streams Back to the Surface

Stream daylighting is defined as bringing a buried stream back to the surface. This paper presents the case for stream daylighting as a viable and more sustainable strategy for CSO mitigation relative to an exclusive focus on conventional gray controls. Two case studies are presented that highlight the applicability of stream daylighting across a range of settings within Cincinnati, Ohio. One project is located in a heavily-congested urban corridor while the other project is in a nature preserve. Both projects are a part of Metropolitan Sewer District of Greater Cincinnati’s(MSDGC’s) green approach to addressing overflows at Cincinnati’s largest CSO, which is estimated to collectively save ∼$180M in life cycle costs relative to the gray alternative. By providing community amenities with repurposed land, the approach has also been described as a catalyst for redevelopment, which further benefits MSDGC by expanding its customer base.