The Arthur R. Marshall Loxahatchee National Wildlife Refuge Water Budget and Water Quality Models 1 Jeanne C. Arceneaux Ehab A. Meselhe Michael G. Waldon Prepared for the US Fish and Wildlife Service, Department of Interior by Institute of Coastal Ecology and Engineering University of Louisiana-Lafayette Report #LOXA-07-004 June 2007 1 Modified from Arceneaux (2007) i Table of Contents List of Tables ................................................................................................................ v List of Figures .............................................................................................................viii Chapter 1: Introduction.................................................................................................. 1 1.1 Background ................................................................................................. 1 1.2 Refuge Water Management .......................................................................... 5 1.3 Site Description ........................................................................................... 9 1.3.1 Vegetation.......................................................................................9 1.3.2 Geology........................................................................................11 1.3.3 Marsh Topography........................................................................11 1.3.4 Canals...........................................................................................14 1.4 Objective of Study ..................................................................................... 15 Chapter 2: Literature Review ........................................................................................17 2.1 Introduction.................................................................................................17 2.2 Everglades Water Budget Modeling.............................................................17 2.2.1 Lin (1979).....................................................................................17 2.2.2 MacVicar et al. (1984)...................................................................18 2.2.3 Richardson et al. (1990).................................................................19 2.2.4 Welter (2002)................................................................................21 2.3 Previous Modeling Completed in Similar Wetlands.....................................22 2.3.1 Kadlec and Hammer (1982) and Kadlec and Knight (1996)...........22 2.3.2 Mitsch (1988) and Mitsch and Reeder (1991)................................24 2.3.3 Wang and Mitsch (2000)...............................................................25 2.4 Everglades Water Quality Modeling............................................................25 2.4.1 Raghunathan et al. (2001)..............................................................26 2.4.2 Munson et al. (2002).....................................................................27 2.4.3 Fitz et al. (2002a)..........................................................................28 2.4.4 Walker (1995)...............................................................................29 2.4.5 Walker and Kadlec (2006).............................................................29 Chapter 3: Data Collection and Analysis.......................................................................31 3.1 Introduction.................................................................................................31 3.2 Precipitation.................................................................................................32 3.3 Evapotranspiration.......................................................................................37 3.4 Flows...........................................................................................................39 3.5 Water Levels................................................................................................44 3.6 Water Quality..............................................................................................45 3.6.1 EVPA Monitoring Sites.................................................................46 3.6.2 XYZ Monitoring Sites...................................................................47 3.6.3 Hydraulic Structures......................................................................48 ii Chapter 4: Water Budget Model....................................................................................50 4.1 Introduction.................................................................................................50 4.2 Modeling Assumptions................................................................................51 4.3 Model Predictions........................................................................................52 4.4 Observed Parameters...................................................................................54 4.4.1 Precipitation..................................................................................54 4.4.2 Evapotranspiration........................................................................56 4.4.3 Inflows and Outflows....................................................................57 4.5 Estimated Parameters...................................................................................59 4.5.1 Exchange Flow..............................................................................59 4.5.2 Groundwater Recharge..................................................................60 4.6 Calibration...................................................................................................61 4.6.1 Calibration Parameters..................................................................62 4.6.2 Calibration Results........................................................................63 4.6.3 Calibration Performance Measures................................................65 4.7 Validation....................................................................................................69 4.7.1 Validation Results.........................................................................69 4.7.2 Validation Performance Measures.................................................71 4.8 Results for Period of Record........................................................................72 4.9 Regulation Schedule Analysis......................................................................72 4.10 Discussion of Results.................................................................................75 4.11 Case Study of Model Application...............................................................76 CHAPTER 5: Water Quality Constituents, Model Selection, and Modeling Approach..84 5.1 Introduction.................................................................................................84 5.2 Constituents to be Modeled..........................................................................85 5.2.1 Chloride........................................................................................85 5.2.2 Phosphorus....................................................................................88 5.3 Model Selection...........................................................................................93 5.4 Water Quality Modeling Approach..............................................................96 CHAPTER 6: Chloride Water Quality Modeling...........................................................99 6.1 Introduction.................................................................................................99 6.2 Chloride Excel Model..................................................................................99 6.2.1 Excel Model Setup......................................................................100 6.2.2 Calibration..................................................................................102 6.2.3 Calibration Results......................................................................104 6.2.4 Validation Results.......................................................................107 6.2.5 Discussion of the Chloride Excel Model......................................111 6.3 Chloride WASP Model..............................................................................111 6.3.1 Chloride WASP Model Setup......................................................111 6.3.2 Chloride WASP Model Calibration.............................................115 6.3.3 Chloride WASP Model Calibration Results.................................116 6.3.4 Chloride WASP Model Validation Results..................................120 6.3.5 Discussion and Further Analysis of the Chloride WASP Model...123 iii CHAPTER 7: Phosphorus Water Quality Modeling....................................................130 7.1. Introduction..............................................................................................130 7.2 Phosphorus WASP Model Setup................................................................130 7.3 Phosphorus WASP Model Calibration.......................................................132 7.4 Phosphorus WASP Model Calibration Results...........................................135 7.5 Phosphorus WASP Model Validation........................................................138 7.6 Discussion and Further Analysis of the Phosphorus WASP Model.............141 CHAPTER 8: Conclusions and Future Developments.................................................145 8.1 Water Budget Model Conclusions..............................................................145 8.2 Water Budget Future Developments...........................................................146 8.3 Chloride Model Conclusions......................................................................147 8.4 Chloride Model Future Developments........................................................148 8.5 Phosphorus Conclusions............................................................................148 8.6 Phosphorus Future Developments..............................................................149 Literature Cited ..........................................................................................................150 APPENDIX A Removed Chloride and Phosphorus Outliers: ......................................160 APPENDIX B: Daily Chloride Excel Model Results...................................................164 APPENDIX C: Daily Chloride WASP Model Results.................................................169 iv List of Tables Table 3.1: Available rainfall data in the Loxahatchee Refuge for the POR (1995 to 2004)....................................................................................................................33 Table 3.2: Availability of flow data in the Loxahatchee Refuge for the POR (1995 to 2004)....................................................................................................................43 Table 4.1: Marsh and canal statistics in the Loxahatchee Refuge for the calibration period January 1, 1995 to December 31, 1999......................................................69 Table 4.2: Marsh and canal statistics in the Loxahatchee Refuge for the validation period January 1, 2000 to December 31, 2004......................................................71 Table 4.3: Marsh and Canal Statistics for Complete POR.............................................72 Table 4.4: Marsh and canal statistics for complete POR (1995 to 2004) using the regulation schedule to predict outflows in the Loxahatchee Refuge.......................75 Table 4.5: Comparison of the marsh modeled water budget statistics to the ELM v.2.1 model...................................................................................................................76 Table 4.6: Comparison of the marsh modeled water budget statistics to the SFWMM model...................................................................................................................76 Table 5.1: Total annual chloride loads going in and out of the Refuge through hydraulic structures and the total percent of chloride retained in the Refuge.........87 Table 5.2: Total phosphorus loads going in and out of the Refuge through hydraulic structures and the total percent of phosphorus retained in the Refuge....................91 Table 5.3: Comparison of the calculated inflow loads against the SFWMD’s loads published in their annual reports for Florida Water Years 2002 to 2004................93 Table 5.4: Comparison of the calculated outflow loads against the SFWMD’s loads published in their annual reports for Florida Water Years 2002 to 2004................93 Table 5.5: Distance of each cell from the Refuge canal and its area..............................97 Table 5.6: Location water quality stations in reference to the canal and interior cells used in calibration of the chloride and phosphorus models....................................98 Table 6.1: Initial and long term average concentrations for chloride in each cell.........102 v Table 6.2: Chloride Excel model performance measures for the calibration period......107 Table 6.3: Chloride Excel model performance measures for the validation period.......110 Table 6.4: Chloride Excel model performance measures for the POR..........................110 Table 6.5: Initial volumes for the canal and interior cells............................................113 Table 6.6: Fraction of flows used in WASP................................................................114 Table 6.7: Areas and distance used to calculate dispersion in the WASP chloride model.................................................................................................................115 Table 6.8: Performance measures for the calibration period using the chloride WASP model.................................................................................................................119 Table 6.9: Performance measure for the validation period using the chloride WASP model.................................................................................................................122 Table 6.10: Performance measure for the POR using the chloride WASP model........123 Table 7.1: Initial conditions for phosphorus and the average observed phosphorus concentration for each cell..................................................................................131 Table 7.2: Fraction of flows used in for calculating settling rate for each cell.............132 Table 7.3: Performance measures for the calibration period using the phosphorus WASP model......................................................................................................137 Table 7.4: Performance measure for the validation period using the phosphorus WASP model......................................................................................................140 Table 7.5: Performance measure for the POR using the phosphorus WASP model.....141 Table 7.6: Statistics in the canal comparing the phosphorus water quality model and the ELM v.2.1 phosphorus model.......................................................................142 Table 7.7: Statistics in the cell 1 comparing the phosphorus water quality model and the ELM v.2.1 phosphorus model.......................................................................143 Table 7.8: Statistics in the cell 2 comparing the phosphorus water quality model and the ELM v.2.1 phosphorus model.......................................................................143 Table 7.9: Statistics in the cell 3 comparing the phosphorus water quality model and the ELM v.2.1 phosphorus model.......................................................................143 vi Table A.1: Chloride outlier values; and dates and values when there were more than recording............................................................................................................161 Table A.2: Dates and values of days when there were more than one phosphorus reading at a inflow or outflow structure..............................................................162 Table A.3: Dates and values of days when there were more than one phosphorus reading at a inflow or outflow structure..............................................................163 vii List of Figures Figure 1.1: Satellite image and location of the Arthur R. Marshall Loxahatchee National Wildlife Refuge. Inset shows the image location within the State of Florida....................................................................................................................1 Figure 1.2: Historic and altered flow patterns for the Everglades system. .......................2 Figure 1.3: Boundaries of the Loxahatchee Refuge.........................................................4 Figure 1.4: Map of Water Conservation Areas (WCAs)..................................................4 Figure 1.5: Water Regulation Schedule for WCA 1........................................................8 Figure 1.6: Plant communities located inside the Refuge.................................................9 Figure 1.7: Refuge vegetation map...............................................................................10 Figure 1.8: Loxahatchee Refuge 2003 USGS topographic data.....................................12 Figure 1.9: North to South ground profile of the Loxahatchee Refuge..........................13 Figure 1.10: West to East ground profile of the Loxahatchee Refuge............................13 Figure 1.11: Location of canals around the perimeter of the marsh...............................14 Figure 3.1: Rain gage locations in and around the Loxahatchee Refuge........................33 Figure 3.2: Seasonal variation of average monthly rainfall in the Loxahatchee Refuge for the POR (1995 to 2004)..................................................................................35 Figure 3.3: Variation of total annual rainfall in the Loxahatchee Refuge for the POR (1995 to 2004)......................................................................................................35 Figure 3.4: Spatial distribution of annual average rainfall in the Loxahatchee Refuge from January 1, 1997, to December 31, 2004........................................................36 Figure 3.5: Seasonal variation of average monthly ET at STA-1W for the Loxahatchee Refuge for the POR (1995 to 2004)......................................................................38 Figure 3.6: Annual variation in total ET at STA-1W for the Loxahatchee Refuge for the POR (1995 to 2004)........................................................................................38 Figure 3.7: Location of hydraulic structures located in the Loxahatchee Refuge...........39 viii Figure 3.8: Various inflow pump stations located in the Loxahatchee Refuge...............40 Figure 3.9: Various outflow structures located in the Loxahatchee Refuge...................41 Figure 3.10: Various structures with bidirectional flows located in the Loxahatchee Refuge..................................................................................................................42 Figure 3.11: Water level sites located in the Loxahatchee Refuge.................................44 Figure 3.12: XYZ and EVPA water quality monitoring sites located inside the Loxahatchee Refuge.............................................................................................46 Figure 3.13: Chloride and TP arithmetic means at Refuge XYZ transect stations with increasing distance from the rim canal..................................................................48 Figure 4.1: Sketch of Water Budget double-box model.................................................51 Figure 4.2: An example of one of the sixteen “Theissen Polygon Method” area distributions used for calculating average daily rainfall in the Loxahatchee Refuge for the POR (1995 to 2004)......................................................................55 Figure 4.3: Canal stages in the Loxahatchee Refuge for the calibration period January 1, 1995, to December 31, 1999 using the water budget model...............................64 Figure 4.4: Marsh stages in the Loxahatchee Refuge for the calibration period January 1, 1995, to December 31, 1999 using the water budget model...............................64 Figure 4.5: Canal stages in the Loxahatchee Refuge for the validation period January 1, 2000, to December 31, 2004 using the water budget model...............................70 Figure 4.6: Marsh stages in the Loxahatchee Refuge for the validation period January 1, 2000, to December 31, 2004 using the water budget model...............................70 Figure 4.7: Canal stage results using the regulation schedule to predict outflow for the period January 1, 1995, to December 31, 2004 in the Loxahatchee Refuge...........74 Figure 4.8: Canal stage results using the regulation schedule to predict outflow for the period January 1, 1995, to December 31, 2004 in the Loxahatchee Refuge......74 Figure 4.9: A comparison of the reduction of inflow from STA1-W to the Refuge based on Alternatives 1 and Alternative 2 in respect to Alternative 0....................79 Figure 4.10: Comparison of Marsh stages using the water budget model to compare the Alternatives 1 and 2 against Alternative 0.......................................................79 Figure 4.11: Time series of estimated marsh Stages for the three alternatives...............80 ix Figure 4.12: Comparison of Canal stages using the water budget model to compare the Alternatives 1 and 2 against Alternative 0.......................................................80 Figure 4.13: Time series of estimated canal Stages for the three alternatives.................81 Figure 4.14: The total number of days when the water depth in the Refuge is greater than 0.8 ft, based on the stage results from the three alternatives...........................82 Figure 4.15: The average number of consecutive days when the water depth in the Refuge is greater than 0.8 ft, based on the stage results from the three alternatives...........................................................................................................83 Figure 4.16: The longest number of consecutive days when the water depth in the Refuge is greater than 0.8 ft, based on the stage results from the three alternatives...........................................................................................................83 Figure 5.1: Total annual chloride loads going in and out of the Refuge through hydraulic structures..............................................................................................87 Figure 5.2: The correlation between the net flow for the POR and the percent chloride retained in the Refuge...........................................................................................88 Figure 5.3: Schematic explaining how the composite phosphorus samples were filled to make a complete time-series.............................................................................90 Figure 5.4: Total annual phosphorus loads going in and out of the Refuge through hydraulic structures..............................................................................................91 Figure 5.5: The correlation between the net flow for the POR and the percent of phosphorus retained in the Refuge........................................................................92 Figure 5.6: Location of EVPA and XYZ water quality monitoring sites in relation to the various cells....................................................................................................97 Figure 6.1: Schematic of cells used to calculate chloride concentrations......................100 Figure 6.2: Canal calibration results for the chloride Excel model, representing the average monthly observed data and its standard deviations; and the average monthly modeled data......................................................................................105 Figure 6.3: Cell 1 calibration results for the chloride Excel model, representing the average monthly observed data and its standard deviations; and the average monthly modeled data......................................................................................105 x