ASSESSMENT OF STREAM FUNCTIONALITY AND LWD IN TWO TRIBUTARIES TO THE BLACK RIVER

Several aspects of stream functionality were determined for two small streams in the Black River watershed in Lorain County, Ohio. It was determined that both streams are Rosgen F5-type streams, indicating that they are entrenched, meandering streams with sand-dominated substrate. Both streams contained notable amounts of large woody debris (LWD), particularly large jams that spanned the width of the channels. This study investigated the effects of log jams on overall stream dynamics, such as flow, bank morphology, suspended sediment, and water quality. Results from LWD surveys indicate noticeable differences in the amount, type, and mobility of LWD in the two streams. Specifically, a large storm in August 2023 resulted in flash flooding and the movement of LWD previously determined to be “stable”. Additionally, results of LWD and bank erosion surveys indicate a significant relationship between bank hazard classification and log jam location. The presence of large log jams upstream of more moderate banks, suggest jams are restricting flow, leading to decreased bank erosion downstream. Stream and park management practices seem to affect the location and abundance of LWD, but more research is needed to explore this hypothesis. The combined effects of land use alteration within the watershed, and increased precipitation because of anthropogenic climate change, may result in more frequent stream changes. For smaller streams, these changes can have a large effect on streamflow, LWD, bank morphology, wildlife, land management, and other variables, thus, additional monitoring and assessment is necessary.