Upper Peace River An Analysis of Minimum Flows and Levels August 25, 2002 DRAFT Ecologic Evaluation Section Resource Conservation and Development Department Southwest Florida Water Management District Brooksville, Florida 34604-6899 Table of Contents Acknowledgments List of Figures List of Tables Acronyms and Abbreviations Executive Summary Chapter One - Minimum Flows and Levels 1.1 Overview 1-1 1.1.1 Legislative Direction 1-1 1.2 Historical Perspective 1-2 1.2.1 The Flow Regime 1-3 1.3 Ecologic Integrity and Significant Harm 1-4 1.4 Components of an MFL 1-5 1.5 Summary of Approach 1-5 1.6 Flows and Levels 1-7 1.7 Content of Remaining Chapters 1-8 Chapter Two - Upper Peace River 2.1 Prologue 2-1 2.2 Basin Characteristics 2-1 2.2.1 Watershed Location 2-2 2.2.2 Climate and Rainfall 2-4 2.2.3 Physiography 2-6 2.2.4 River Channel and Floodplain Morphology 2-7 2.2.5 Hydrology/Hydrogeology 2-8 2.2.5.1 Surficial Aquifer 2-8 2.2.5.2 Intermediate Aquifer 2-10 2.2.5.3 Upper Floridan Aquifer 2-12 2.2.5.4 Relationship of Peace River to Aquifers 2-12 2.3 Chronology of Watershed Development 2-16 Chapter Three - Hydrologic Trends and Water Quality 3.1 Overview 3-1 3.1.1 Gage Sites and Period of Record 3-1 3.2 Documentation of Declining Flow Trends 3-3 Draft as of 8/27/02 i 3.2.1 Recent Trend Analyses at Long-Term Gages 3-3 3.2.2 Trends in Annaul Percent Exceedance Flows 3-8 3.2.3 Comparison of High and Low Flow Months 3-15 3.2.3.1 Flow Contributions from Upstream 3-16 3.2.4 Changes in Monthly Flows at Bartow Gage 3-20 3.2.5 Trends in Water Levels 3-23 3.3 Factors Affecting Flows in the Upper Peace River 3-26 3.3.1 Effects of Long-Term Changes in Rainfall 3-27 3.3.2 Effects of Ground-Water Withdrawals 3-30 3.3.3 Reduction or Elimination of Waste Water Discharges 3-34 3.3.4 Effects of Structural Alterations and Changes 3-35 3.3.4.1 Peace Creek 3-41 3.3.4.2 Saddle Creek 3-48 3.3.4.3 Peace River at Zolfo Springs 3-52 3.3.4.4 Payne Creek 3-55 3.3.4.5 Summary of Alterations and Changes 3-55 3.3.5 Relevance of All Impacts to Declining Flows and the Establishment of Minimum Flows 3-58 3.4 Water Quality 3-59 3.4.1 Macronutrients: Phosphorus and Nitrogen 3-60 3.4.1.1 Phosphorus 3-60 3.4.1.2 Nitrogen 3-66 3.4.2 Potassium 3-68 3.4.3 Dissolved Oxygen 3-71 3.4.4 Other Water Quality Studies 3-71 3.4.5 Water Quality Summary 3-72 Chapter Four - Ecological Resources of Concern 4.1 Resources and Area of Concern 4-1 4.2 Resource Management Goals and Key Habitat Indicators 4-1 4.2.1 Fish Passage 4-2 4.2.2 Wetted Perimeter Inflection Point 4-2 4.2.3 Instream Woody Habitat 4-3 4.2.4 Hydrologic Requirements of Floodplain 4-4 4.2.4.1 Wetland Plant Communities 4-5 4.2.4.2 Soils 4-5 4.2.4.3 Fish and Wildlife 4-6 Chapter Five - Technical Approach 5.1 Overview: Determining Hydrologic Requirements 5-1 5.2 HEC-RAS Modeling 5-1 5.3 Application of HEC-RAS to Fish Passage Depths 5-4 5.4 Application of HEC-RAS to Wetted Perimeter 5-7 Draft as of 8/27/02 ii 5.5 Establishment of Low Minimum Flows and Levels 5-7 5.6 Cross Sectional Surveys of Habitats 5-10 5.2.1 Transect Selection 5-10 5.2.2 Field Sampling: Floodplain Habitats 5-15 5.2.3 Soils Characterization 5-15 5.2.4 Instream Habitats 5-16 5.7 Inundation Characteristics of Habitats 5-18 5.7.1 Historical Inundation Analysis 5-18 5.7.2 Selection of Reference and Recent Periods 5-19 5.7.3 Sources of Uncertainty in Inundation Analysis 5-22 Chapter Six - Results 6.1 Overview 6-1 6.2 Fish Passage 6-1 6.2.1 Adequacy of the 0.6 Foot Criterion 6-1 6.2.2 Minimum Flows Needed for Fish Passage 6-4 6.3 Wetted Perimeter Inflection Points 6-7 6.4 Proposed Low Minimum Flows 6-9 6.5 Instream Habitats 6-11 6.5.1 Channel Characteristics 6-11 6.5.2 Instream Habitats - Lateral Distribution 6-14 6.5.3 Instream Habitats - Vertical Distributions 6-14 6.5.4 Flow Relationships with Woody Habitats 6-17 6.5.5 Woody Habitat Inundation - Bartow to Ft. Meade 6-20 6.5.6 Woody Habitat Inundation - Ft. Meade to Zolfo 6-23 6.5.7 Development of a Medium Flow Standard 6-24 6.6 Floodplain Wetlands 6-30 6.6.1 Wetland Distributions from NWI Maps 6-30 6.6.2 Vegetation Characterization from Field Studies 6-37 6.6.3 Soils 6-43 6.6.4 Wetted Perimeter and Floodplain Habitats 6-46 6.6.5 Inundation Characteristics of Floodplain 6-49 6.6.5.1 Statistical Comparison of Periods 6-53 6.6.5.2 Comparisons with Other Systems 6-63 6.6.5.3 Changes in Hydrologic Indicators 6-65 6.7 Wildlife Use of Floodplain Habitats 6-68 6.7.1 Amphibians 6-68 6.7.1.1 Inundation of Amphibian Habitats 6-71 6.7.1.2 Using Amphibians for Developing Minimum Flow Criteria 6-75 6.7.2 Fishes 6-80 6.8 Conclusions and Recommendations 6-82 References Cited References-1 Draft as of 8/27/02 iii Appendices FD - Fish Data FD-1 NWI - National Wetlands Inventory NWI-1 IH - Instream Habitats IH-1 QE - Flows/Exceedance QE-1 QM - Flows/Monthly QM-1 QX - Mean Annual Flows QX-1 RF - Rainfall RF-1 RH - Riparian Habitat RH-1 WP - Wetted Perimeter WP-1 WQ - Water Quality WQ-1 Draft as of 8/27/02 iv Acknowledgments Draft as of 8/27/02 v List of Figures Figure Caption Page Chapter Two Figure 2-1. Peace River watershed 2-3 Figure 2-2. Distribution of rainfall and flow by month at Bartow in the Upper Peace River 2-5 Figure 2-3. 5-year running averages of mean flows for three rivers 2-5 Figure 2-4. Change in river bed elevation between the Bartow gage and the Zolfo Springs gage 2-7 Figure 2-5. Generalized hydrogeologic cross section through the area of the SWFWMD 2-9 Figure 2-6. Generalized potentiometric surface of the Upper Floridan Aquifer along the Peace River 2-11 Figure 2-7. Karstic features located in the riverbed and floodplain of the Upper Peace River 2-14 Figure 2-8. Kissengen Spring 2-15 Chapter Three Figure 3-1. Peace River watershed showing location of USGS gage sites 3-2 Figure 3-2. Hydrographs of mean annual flows at four USGS streamflow gages on the Peace River 3-4 Figure 3-3a. Hydrographs of the minimum, 90%, 50% and 10% annual exceedance flows at Bartow Gage 3-9 Figure 3-3b. Hydrographs of the minimum, 90%, 50% and 10% annual exceedance flows at Ft. Meade Gage 3-10 Figure 3-3c. Hydrographs of the minimum, 90%, 50% and 10% annual exceedance flows at Zolfo Springs Gage 3-11 Draft as of 8/27/02 vi Figure 3-3d. Hydrographs of the minimum, 90%, 50% and 10% annual exceedance flows at Arcadia Gage 3-12 Figure 3-4. Comparison of mean annual flow with 30% exceedance and median flow at Bartow Gage 3-13 Figure 3-5. Mean monthly flows at Arcadia for the period of record 3-15 Figure 3-6. Zolfo Springs September and Bartow September flows as a percentage of September flow at Arcadia 3-18 Figure 3-7. Zolfo Springs May and Bartow May flows as a percentage of May flows at Arcadia 3-19 Figure 3-8. Contribution of mean monthly flows to the mean annual flow at the USGS Bartow Gage for the period of record 3-21 Figure 3-9. Contribution of mean monthly flows to the mean annual flow at the USGS Bartow Gage for the period 1985 to 2000 3-22 Figure 3-10. Hydrographs of the minimum, 90%, 50% and 10% annual exceedance stage at the USGS Bartow Gage 3-24 Figure 3-11. Hydrographs of the minimum, 90%, 50% and 10% annual exceedance stage at the USGS Zolfo Springs Gage 3-25 Figure 3-12. Sinks and subsidence features along the Upper Peace River corridor 3-33 Figure 3-13. Map of Peace River basin showing ten major sub-basins 3-36 Figure 3-14. Comparison of 1999 landcover in the Peace River basin and the Upper Peace River basin 3-39 Figure 3-15. 1999 landcover in Peace Creek sub-basin 3-42 Figure 3-16. 1999 landcover in the Saddle Creek sub-basin 3-50 Figure 3-17. 1999 landcover in the Zolfo Springs sub-basin 3-53 Figure 3-18. 1999 landcover in the Payne Creek sub-basin 3-56 Figure 3-19. Phosphorus concentrations in water samples collected by USGS at four long-term gage sites on the Peace River 3-62 Draft as of 8/27/02 vii Figure 3-20.