Researchers are testing new methods to prevent erosion of streambanks in the days following floods, according to an April 27 announcement. The project focuses on stabilizing banks during the vulnerable period between reconstruction and when vegetation is established.
This research is important because erosion during this window can lead to excess sediment, which harms aquatic habitats and water quality. Sediment increases treatment costs for drinking water and wastewater facilities.
Keegan O’Hara, a senior and accelerated master’s degree student in the Department of Biological Systems Engineering, is developing a process that encourages soil microorganisms to create substances acting like glue to strengthen newly reconstructed streambanks until plants can grow. “The less erosion you have from a bank, the healthier the water will be,” he said.
O’Hara’s work builds on earlier studies by Daniel Smith Ph.D. ’22 and Michael Snead ’22 in Tess Thompson’s lab. Their previous research showed that adding small amounts of organic matter stimulates soil microorganisms, increasing production of sticky substances that bind soil particles together and reduce erosion. To further test this approach for stream restoration, O’Hara is evaluating wood chips, straw, and hemp-based substrates mixed into soil at different densities before being tested for resistance in laboratory conditions. “We’re hoping to identify one or two mixtures that noticeably improve soil cohesiveness,” O’Hara said. “If we can show that, it could become a simple, low-cost addition to restoration work.”
Thompson said: “By determining how streambank erosion resistance changes with different types and amounts of readily available organic matter, the results of Keegan’s research will be directly applicable to the stream restoration practice, improving the success of restoration projects.” Many current projects use plastic mesh or rock armoring for stabilization; however these methods may cause long-term problems such as microplastics or shifting downstream erosion.
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O’Hara said: “This is something that could help balance ecological goals with infrastructure needs. And in the future, it could be applied beyond streams to other construction areas that face erosion challenges.”
