Year Established: 2015 Start Date: 2015-03-01 End Date: 2016-02-28
Total Federal Funds: $19,850 Total Non-Federal Funds: $39,893
Principal Investigators: Zhi-Qiang Deng
Abstract: The latest (2014) Louisiana Water Quality Inventory - Integrated Report (305(b)/303(d)) stated that low DO (Dissolved Oxygen), used to determine support of the FWP (fish and wildlife propagation) use, continues to be the most frequently cited suspected cause of impairment with 177 subsegments affected. While extensive efforts have been made to address the low DO problem through the development and implementation of Total Maximum Daily Load (TMDL), there was no significant improving trend in FWP use of Louisiana water bodies in the past 15 years (2000 - 2014). Basically, the pollution load reduction through TMDL implementation was counterbalanced by the load increase due to pollution sources produced by changing land use and land cover. Since the land use and land cover change is a dynamic process, the source of DO impairment should also be dynamic. It means that a static TMDL or a fixed percentage (typically 10 – 20%) of margin of safety for TMDL is unable to maintain water quality in the long run in terms of designated uses. This is exactly what happened in Louisiana and in the Gulf of Mexico region as well. Therefore, the development of dynamic TMDL is essential to the restoration and sustainability of water quality and thereby to meeting designated uses (particularly FWP) of Louisiana water bodies. This is a critical regional and state water quality problem needing to be addressed. The overall goal of this project is to develop a new approach, called dynamic TMDL development and implementation, to the restoration of water quality and the sustainability of designated uses of Louisiana water bodies, addressing the critical regional and state water quality problem. The proposed strategy is to test and demonstrate the new watershed-based modeling approach by developing TMDL for DO in the Lower Bayou Macon (subsegment LA081001_00) that is impaired due to low dissolved oxygen. The specific objectives of this project are (1) to identify critical BOD sources in the Bayou Macon watershed and calculate BOD loadings into the Lower Bayou Macon under changing land use and land cover conditions, (2) to simulate DO levels in the Lower Bayou Macon and develop TMDL for DO under the dynamic BOD sources due to the changing land use and land cover in the watershed, and (3) to determine the optimum combination of BMPs for implementation of the TMDL and thereby for achieving designated use of the bayou under dynamic sources. The objectives will be addressed by integrated watershed and instream modeling using the VART DO-3L model developed by PI’s research group and the watershed modeling tools HSPF (Hydrologic Simulation Programming-Fortran) model and SWAT (Soil & Water Assessment Tool) model. The proposed project has broader implications for environmental restoration and sustainability in Louisiana and in the nation as well. This project will provide a new approach for environmental and water resources management agencies (such as Louisiana Department of Environmental Quality) to identify critical source areas of dynamic BOD pollution and restore designated uses of impaired water bodies. While this project focuses on the Lower Bayou Macon watershed, the dynamic approach to TMDL development and implementation can be easily extended to other watersheds in Louisiana and in the nation. In addition, the project provides potential research and educational training opportunities for graduate and undergraduate students. This proposal is intended to address the two research priorities: (1) Watershed Education and Research Activities and (2) Total maximum daily load (TMDL) calculations in Louisiana water bodies, identified by the Louisiana Water Resources Research Institute (LWRRI) in LWRRI’s Research Priorities for 2015.