Thursday, September 28, 2023 - 4:02AM
Lawrence Ephram Band, Ern Professor of Environmental Science, Professor of Engineering Systems and Environment, University of Virginia
Urbanized watersheds accelerate the loading of stormwater, sediment, and nutrients into local streams and receiving water bodies. Stream channel restoration has grown significantly over the last two decades, with goals of reducing stabilizing streams, reducing sediment and nutrient export. However, peak urban flows can provide the bulk of total annual nutrient loads at discharges that bypass limited stream ecosystem processing capacity, and erode and destabilize channel restoration design, leading to limited restoration efficacy and design failure. Hydrologic flow regimes providing the highest potential for channel restoration reduction in nutrient export tend to occur in less developed catchments, leading to a spatial asynchrony in ecosystem and community benefits. To promote sustainability, efficacy, and equity, channel manipulation needs to be balanced with upland practices designed to reduce runoff and nutrient loading regimes, and increase "urban green" benefits in higher density areas. We present long term monitoring data, experiments, and coupled watershed ecohydrologic and aquatic ecosystem process models to evaluate the spatial synchrony of current restoration outcomes for nutrient reduction and community benefits, and the balance in terrestrial and aquatic restoration required to promote both ecosystem and equity outcomes. The model is operated at resolutions designed to incorporate residential input and feedback on restoration design, and evaluate community preference and equity....