A recent survey of streams in a Northeast Ohio watershed is helping local partners use watershed-scale solutions to address problems like streambank erosion.
Results from a headwater stream assessment of 42 sites in the Pepper/Luce Creek watershed showed that the area has widespread erosion and identified ideal places for maintaining or restoring habitat. Now, those results are informing ongoing efforts to improve overall watershed quality.
The project, led by Keely Davidson-Bennett of Chagrin River Watershed Partners (CRWP) and funded by Ohio Sea Grant, arose after the City of Pepper Pike and Village of Hunting Valley expressed concerns about the quality of the streams — namely Pepper Creek and Luce Creek — in their communities.
“Erosion in streambanks is concerning from a variety of different perspectives,” said Davidson-Bennett, director of special projects for CRWP. “One is” that it has a negative impact on water quality and aquatic habitat. The sediment that’s eroding from the banks goes into the water that the stream is carrying, and it fills in the spaces between the rocks where the bugs in the water live, which means less food for the fish or salamanders.”
Another issue: Erosion can damage people’s property and infrastructure along streambanks, leading to safety concerns and repair costs, Davidson-Bennett explained. Meanwhile, intense storms that accelerate streambank erosion are expected to increase in frequency due to climate change.
To address these concerns, researchers used two existing metrics to evaluate both habitat quality and erosion severity in 200-foot stretches of stream throughout the Pepper/Luce Creek watershed during the summer of 2022. For one, the team used Ohio Environmental Protection Agency habitat evaluation indexes to identify 11 sites with high quality “class III” primary headwater stream habitat.
“It’s useful to have an understanding of habitat quality because it helps us understand the restorability of impaired reaches,” Davidson-Bennett said. “It also helps us understand what areas of the watershed already have high quality waters, where preserving existing conditions is important.”
In addition, researchers used a modified version of the Bank Erosion Habitat Index to weigh factors such as the depth of roots near streambanks, root density, bank height, and bank material.
“The index looks at all of those things to give you a numerical score that you can then convert into categories based on erosion severity, from very low to extreme,” Davidson-Bennett said.
Of the 42 sites assessed, 35 had erosion ratings of “high” or above.
“Having widespread erosion throughout a watershed points to the need for watershed-scale solutions like better stormwater management rather than indicating that we just have a few localized problems,” Davidson-Bennett said.
In response to these results, CRWP started a follow-up project with The Ohio State University’s Winston Lab to look at the feasibility of retrofitting stormwater basins in the headwaters of the Pepper/Luce Creek watershed. The work should be completed by the fall of 2024, Davidson-Bennett said.
“We want to look at these older stormwater basins to see if we can modify them to decrease the rate at which they release flows from common storms so that we can hopefully decrease stream bank erosion within this watershed,” she said.
The results will further assist in targeting streambank stabilization, stream and wetland restoration, stormwater management, and land protection projects. Data gathered also supplements similar assessments recently conducted by the Northeast Ohio Regional Sewer District.
“It gave us some useful data that we didn’t have throughout the whole watershed, which helped us get an idea of the types of strategies would be most helpful for this watershed,” Davidson-Bennett said of the assessment. “In the future, we’ll be able to use the data we collected now to see improvement or see if things are getting worse. So having baseline data will allow us to potentially do some temporal studies as well.”
Ohio Sea Grant is supported by The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES) School of Environment and Natural Resources, Ohio State University Extension, and NOAA Sea Grant, a network of 34 Sea Grant programs nation-wide dedicated to the protection and sustainable use of marine and Great Lakes resources. Stone Laboratory is Ohio State’s island campus on Lake Erie and is the research, education, and outreach facility of Ohio Sea Grant and part of CFAES School of Environment and Natural Resources.