Innovative Stormwater Projects
CWMTF defines “innovative stormwater projects” as projects that: 1) bring something new or different to practices in stormwater-quality management, 2) build on experience and current practices, and 3) advance practices in stormwater-quality management regionally or statewide. Innovative stormwater projects will focus on developing and applying new information. These projects will emphasize developing representative and defensible monitoring data and cost data, evaluating system effectiveness and performance in field applications, evaluating economic and social benefits, and disseminating findings and results. Approaches should provide for evaluating success in the context of the project’s objectives and explaining why objectives were achieved or not achieved.
City of Raleigh - Market at Colonade
This infill development site utilized a combination of bioswales, cisterns, detention/infiltration chambers (pictured), and a wooded irrigation area to detain and treat stormwater on a site with a very high impervious area (84%). The system, and particularly the infiltration chambers, was so effective that only 2% of all the rainfall that fell on this site left as runoff during the study period, compared to nearly 50% that left the control site: a standard development with a conventional wet detention basin. Though it was more costly, this method proved to be more effective, more attrictve and allowed more of the property to be utilized for retail space. As an added bonus, these green features were consistent with the ethos of the tenant, Whole Foods.
Upper Sandy Creek - Anabranching Wetland
Floodplains and riparian wetlands can be effective in reducing pollutants introduced into the stream during runoff events. However, in a typcial channel, these features are only accessed a few times a year. In this project, the stream and floodplain were designed to facilitate a much more frequent interaction: 1 - 2 times per month. Monitoring revealed this additional contact and residence time recudes pollutants such as sediment and nutrients compared to conventional techniques.
Wrightsville Beach - Stormwater Infiltration
In many coastal communities, stormwater runoff is causing real issues with bacteria which can close beaches and shellfish areas. The NC Coastal Federation is working on a project to disconnect some of the stormwater runoff and infiltrate it into the sandy soils using large perforated pipe (pictured). This should reduce overall runoff and the fecal coliforms that it carries with it. This one is still in progress so stay tuned!