*This project was undertaken with the Ohio EPA and USACE Buffalo District as part of Healthy Port Futures. For a more detailed explanation of the project see the HPF website.
Our concept for the Lorain Ring is a nearshore structure with a variable crest height that retains sediment and works with fluctuating water levels and waves to produce a complex hemi-marsh habitat and slowly release sediment back into the nearshore environment. Because open lake sediment disposal is illegal in the state of Ohio (Senate Bill 1, 2016), there was a need to devise new innovative and cost-effective options for sediment placement and wetland restoration. This project was developed for the Ohio EPA to assist the Buffalo District of the USACE in creating a wetland using dredged sediment (section 204 beneficial use).
Historically, rivers in Northern Ohio would move sediment through littoral and floodplain wetlands before reaching Lake Erie. Industrial centers and hardened shorelines from development have displaced historic wetlands and created a need for dredging. We helped the USACE consider alternative sites for dredge material placement, and develop a form that would retain sediment and produce marsh while offering nearby coastal protection. The results of the research are a variable crest height ring that works over time as a wetland making machine, providing a place to build sediment and cultivate the seeds and rhizomes that are then slowly released into the nearshore.
In the central basin of Lake Erie one dominant type of wetland, drowned rivermouth, has been almost completely replaced by industrial port landscapes. Loss of wetlands affects sediment management, nutrient processing, and flooding mitigation. It also results in the loss of important spawning and flyover habitat. Past practices either placed the sediment in confined disposal facilities (CDFs) or unconfined in the deep open water. Both practices remove the sediment from the nearshore system, preventing its potential use in coastal protection, habitat creation, wave attenuation, and sediment nourishment.
The Crescent Sill adapts to different environmental conditions. It is optimized to minimize stone used in the sill structure, maximize sediment placement and wetland surface area, and allow for variable protection. It can be altered to hold different amounts of dredged material, protect against various predominant wave directions, support different wetland habitat types, and create increased wetland complexity.