Stream Relocation Design and Monitoring in a Rapidly Urbanizing Watershed: EFWLC, Indianapolis, Indiana

Recent expansion of the Indianapolis Airport and supporting interstate infrastructure resulted in the relocation of over two miles of the East Fork White Lick Creek (EFWLC) and North Creek (NC). Design of the relocated channels was conducted using natural channel design methodologies intended to improve the overall condition of the EFWLC and NC as compared to the pre-construction condition. The design of the channel relocation was based upon the inter-relationship of hydrology, hydraulics, and geomorphology. Because of anticipated development in the watershed associated with the relocation and expansion of the airport, design criteria for the relocated channels needed to address the existing hydrology and land use, as well as an anticipated hydrologic and hydraulic condition under future land use changes. Geomorphic, biological, chemical, and hydraulic conditions are being monitored to evaluate the success of the stream relocation for verification of compliance with the permit conditions. Five years after completion of construction, both channels continue to adjust to their watershed condition but appear to be stable overall. Each channel is experiencing an appropriate number of bankfull events annually. Available habitat and sampled biological communities show that the relocated channels are generally healthy and improving year to year. Most indices show the relocated channels to be in as-good or better condition than the pre-construction condition or the undisturbed portions of each channel immediately upstream of the relocation.