University of New Orleans ScholarWorks@UNO University of New Orleans Theses and Dissertations Dissertations and Theses 12-17-2010 Water Quality Modeling of Freshwater Diversions in the Barataria Basin Jeevan Neupane University of New Orleans Follow this and additional works at: http://scholarworks.uno.edu/td Recommended Citation Neupane, Jeevan, "Water Quality Modeling of Freshwater Diversions in the Barataria Basin" (2010). University of New Orleans Theses and Dissertations. Paper 1255. This Thesis is brought to you for free and open access by the Dissertations and Theses at ScholarWorks@UNO. It has been accepted for inclusion in University of New Orleans Theses and Dissertations by an authorized administrator of ScholarWorks@UNO. The uthora is solely responsible for ensuring compliance with copyright. For more information, please contact [email protected]. Water Quality Modeling of Freshwater Diversions in the Barataria Basin A Thesis Submitted to the Graduate Faculty of the University of New Orleans in partial fulfillment of the requirements for the degree of Master of Science in Engineering Department of Civil and Environmental Engineering by Jeevan Neupane Tribhuwan University, Nepal, 2007 December, 2010 Acknowledgements First of all I would like to thank my major professor, Dr. Alex McCorquodale. His knowledge, co-operation, support and proper guidelines are worth appreciation. I am grateful to get an opportunity to work under his supervision for the last two years. I would also like to thank the other members of my committee, Dr. Gianna Cothren and Dr. Bhaskar Kura. Their guidance and support of my research are really great. I would like to thank Dr. Ioannis Georgiou for his support, co-operation help for the last two years. I would like to thank the U.S. Geological Survey (USGS), the Louisiana Department of Environmental Quality (LADEQ), the U.S. Army Corps of Engineers (USACE), the Louisiana Universities Marine Consortium (LUMCON), National Climatic Data Center (NCDC), Coastwide Reference Monitoring System (CRMS) and National Data Buoy Center (NDBC) for their water data needed for this research. I would like to thank Jennifer Schindler, Mallory Anne Davis and Joao Pereira who helped me in my research in different ways. I would also like to say a special thank you to my mother and father who have supported and loved me throughout my good and bad time. Finally, I would like thank Lake Pontchartrain Basin Foundation (LPBF) for funding this research. ii Table of Contents List of Figures ................................................................................................. v List of Tables ................................................................................................. ix Abstract ........................................................................................................... x Table of Contents 1.0 Introduction ...............................................................................................................1 1.1 The Barataria Basin ...............................................................................................1 1.2 Freshwater diversions ............................................................................................2 1.2.1 Existing diversions .........................................................................................2 1.2.2 Proposed diversions .......................................................................................3 1.3 Problem Statement ................................................................................................4 1.4 Objectives ..............................................................................................................5 1.5 Methodology .........................................................................................................5 2.0 Background ...............................................................................................................6 2.1 Coastal Wetlands ...................................................................................................6 2.1.1 Formation of the Coastal Wetlands................................................................6 2.1.2 Coastal Wetlands of Louisiana. .....................................................................6 2.2 Existing Diversions ...............................................................................................7 2.2.1 Davis Pond Diversion ....................................................................................7 2.2.2 Caernarvon Diversion ....................................................................................8 2.2.3 Bonnet Carré Diversion .................................................................................9 2.2.4 Naomi Freshwater Diversion .......................................................................10 2.2.5 West Point a la Hache ..................................................................................13 3.0 Literature Review....................................................................................................16 3.1 Introduction .........................................................................................................16 3.2 Nitrogen Cycle ....................................................................................................16 3.3 Phosphorus Cycle ................................................................................................17 3.4 Carbon Cycle .......................................................................................................18 3.5 Previous Studies ..................................................................................................19 4.0 Model Description ..................................................................................................24 4.1 Introduction .........................................................................................................24 4.2 Model description ................................................................................................24 4.2.1 General model description ...........................................................................24 4.3 Governing equations ...........................................................................................26 4.4 Nitrite + Nitrate as nitrogen chemical description ..............................................27 4.5 Organic nitrogen chemical description ...............................................................28 4.6 Phosphorus chemical description ........................................................................28 iii 5.0 Model Inputs ...........................................................................................................29 5.1 Introduction .........................................................................................................29 5.2 Model Cell and link inputs ..................................................................................29 5.3 Tributary Inputs. ..................................................................................................32 5.4 Hydrological inputs. ............................................................................................34 5.5 Diversion flow inputs. .........................................................................................36 5.6 Mississippi Flow .................................................................................................38 5.7 Open Boundary Conditions. ................................................................................39 5.8 Initial Boundary Conditions ................................................................................41 5.9 Future Scenarios ..................................................................................................41 6.0 Model Calibration ...................................................................................................45 6.1 Introduction .........................................................................................................45 6.2 Calibration of Stage .............................................................................................45 6.2 Calibration of Salinity .........................................................................................51 6.3 Calibration of Nutrients .......................................................................................55 7.0 Results .....................................................................................................................59 7.1 Introduction .........................................................................................................59 7.2 Impacts of Diversions on Salinity .......................................................................59 7.3 Impacts of Diversions Scenarios on Salinity Gradients. .....................................67 7.4 Effect of Closing of West Bay ............................................................................69 7.5 Impacts of Diversions on Water Level:...............................................................72 7.6 Impacts of Diversions on Nutrients .....................................................................80 8.0 Discussions .............................................................................................................94 8.1 Introduction .........................................................................................................94 8.2 Uncertainty ..........................................................................................................94