MODELING THE HYDROLOGICAL IMPACTS OF STREAM RESTORATION IN RED BROOK, A SMALL COASTAL STREAM IN SOUTHEASTERN MASSACHUSETTS

New England has a long history of anthropogenic modification of stream channels. Many fluvial systems have been drastically altered from their natural state, whether for flood control, power generation, or navigation purposes. In the case of Red Brook, a small coastal stream in southeastern Massachusetts, the channel and bank morphology has been significantly modified for cranberry bog operations and recreational fishing. Concrete flumes and earthen berms remain along the lower reach of the stream, but a cooperative restoration effort is currently underway. Started in 2006, the project is being coordinated by Massachusetts Riverways Program, with help from the property's caretakers, The Trustees of Reservations, as well as other interested stakeholders. Restoration plans include removal of the concrete structures, regrading and replanting the banks, and emplacement of large woody debris. Ultimately, the goal of this project is to restore habitat for the endemic sea-run brook trout population, which prefer a gravel bed, and the cool, spring-fed waters of Red Brook.

Monitoring of the stream restoration has been ongoing since spring of 2008, using a combination of in-situ measurements, geophysical techniques and a remotely-accessed environmental sensor network to monitor flow and sediment movement in the Brook before and after the flume removal. The monitoring program also includes the development of a computer model of the Brook using HEC-RAS, a one-dimensional water surface profile model developed by the U.S. Army Corps of Engineers. The purpose of this model is to simulate streamflow conditions before and after flume removal, and to predict the overall impact of stream restoration activities on the flow and sediment transport regimes of Red Brook. Some of the challenges involved with modeling Red Brook include a strong tidal influence within the lower reaches and cranberry bog operations in the upper reaches of the Brook. Modeling these unique aspects will provide insight into the sensitivity of coastal streams to natural and artificial flow controls, as well as evaluating the success of the restoration project in terms of channel morphology, flow conditions, and sediment transport.