Speaking

The Ohio Environmental Protection Agency conducted evaluations of 50 wetlands statewide to test the efficacy of alternative wetland assessment methods to the ORAM and VIBI. These alternative methods were statistically evaluated to determine if they could be utilized for wetland scoring and during wetland mitigation monitoring. 

Nitrogen and phosphorus are common nutrients of concern in Ohio’s rivers, ponds and streams after large rain events. They have been noted to lead to eutrophication in high concentrations, which has resulted in the development of algal blooms and oxygen depletion in the receiving water bodies. With the understanding that elevated nitrogen and phosphorus concentrations can be a result of fertilizer runoff from agricultural fields, lawns and other industrial sources entering a water body, the Ohio Department of Natural Resources developed the H2Ohio program to assist entities in developing methods of lowering these nutrient concentrations in our waterways. 

Wetland treatment system design is an effective method to capture and treat high nutrient loads after a storm event. Through the utilization of river flow data, key flood elevations can be calculated and used to design the wetland flooding frequency. Native plant species and appropriate residence time facilitates the removal of nutrients and turbidity. Hydraulic modeling of the treatment wetland ensures that it is functioning and flooding as intended. This case study showcases a Columbus and Fanklin County Metro Parks project at Walnut Woods Metro Park along Walnut Creek, which was identified as an at-risk waterway for high nutrient loads and selected to receive the H2Ohio grant. It outlines the methodology employed in the wetland design and modeling of the stream and wetland to increase flood frequency. The presentation will also discuss potential implications for similar at-risk sites in Ohio.