Water Resources Research Act Program

Details for Project ID 2019PA226B

Long-term effectiveness of stream restoration activities

Institute: Pennsylvania
Year Established: 2019 Start Date: 2019-05-31 End Date: 2020-05-30
Total Federal Funds: $20,957 Total Non-Federal Funds: $41,914

Principal Investigators: Shirley E. Clark

Abstract: The Chesapeake Bay Total Maximum Daily Load (TMDL) focuses on the reduction/removal of sediment and nutrients from waters that flow into the Chesapeake Bay. Currently, stream restoration is one of the commonly-used and commonly-disputed methods used to document the potential achievement of water-quality objectives. Data on stream restoration effectiveness typically comes from studies conducted 1 – 3 years after restoration, where benefits are expected simply from removing legacy sediments from prior agricultural and industrial activities. However, credit is being given for pollutant reduction for years beyond which there is good data. In addition, limited information is available on which techniques, ranging from engineered bank stabilization to full floodplain reconnection, are the most effective at achieving these water quality goals. Currently the Chesapeake Bay Urban Stormwater Work Group’s Stream Health Work Group is updating the guidance available to municipalities and engineers regarding pollution reduction credits associated with stream restoration. Research such as this will inform these decisions going forward and will be shared with the Expert Panels to support their updating of the literature on the topic of stream restoration effectiveness. The purpose of this project is to study a single stream, Lititz Run, where multiple restoration actions have occurred over the past 20 years. Lititz Run is an ideal stream to evaluate, as it has been the subject of several citizen science data collection efforts for the past 20 years. Additionally, portions of Lititz Run have been evaluated by this research team over the past 3 years. Despite the plethora of background data, no projects have focused on examining the cumulative effects of the multiple restoration projects on a single stream, as we propose here. The objective of this research is to determine whether the type of restoration affects water and sediment quality both immediately downstream and further downstream of the restoration with a focus on restorations that have been in place for at least 10 years. Studying streams that have been restored for at least a decade will provide insight into the temporality of the restoration effectiveness in the stream reach and the cumulative effects on downstream water quality. The stream will be studied longitudinally to determine the effectiveness of the various types of stream restoration 5 – 20 years post-restoration. Stream restoration activities will be primarily divided into floodplain reconnection or engineered stabilization without floodplain reconnection. In-field data will be collected on flow, geomorphology, water quality, and include a riparian assessment. Additionally, water and sediment samples will be collected for nutrients and heavy metals analyses. Sample collection will occur in the spring and fall, before and after summer agricultural activities.