Graduate Assistant University of Tennessee, Tennessee, United States
Abstract Submission: The Clean Water Act (CWA) is evolving, as evidenced in recent years, but its mission remains the same: to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters. The Compensatory Mitigation Rule for Losses of Aquatic Resources (2008 Rule) expanded compensatory mitigation procedures under the CWA, solidifying a market-based approach to stream restoration. Central to the 2008 Rule is the Watershed Approach, designed to promote holistic strategies for restoration practices, but its potential remains underexplored. Despite a burgeoning stream restoration industry, recovery of biological integrity in urbanized landscapes remains inconsistent and, at times, unattainable. Recent trends, such as the Whole Watershed Act in the Chesapeake Bay, highlight current efforts to explore catchment-scale restoration to tackle such challenges. This presentation introduces a compensatory mitigation framework integrating catchment-scale stormwater management and reach-scale stream restoration practices in urbanizing watersheds with an emphasis on biological integrity. A key component of this framework is its connection to Section 303(d) of the CWA, potentially linking ecological performance standards to compensatory mitigation. The framework integrates hydrologic stormwater practices with ecohydraulic modeling using SWMM and River2D. It incorporates weighted usable area (WUA) based on fish and macroinvertebrates guilds, aligning with 303(d) impairment specifications. Functional categories for measuring restoration success include sediment, riparian corridor, and habitat - key drivers of ecological conditions in streams. A case study of an impaired Tennessee creek, listed on 303(d) due to sedimentation, will be presented to illustrate the application of this framework to an urbanizing watershed.
