State of the Watershed Report East Holland River Subwatershed completed by The Lake Simcoe Region Conservation Authority 2000 ACKNOWLEDGEMENTS The successful completion of the State of the Watershed Report would not have been possible without the support and participation of the members of the Steering Committee, Public Advisory Committee and the public who attended the Open Houses or provided comments. The Lake Simcoe Region Conservation Authority would like to thank the following for their cooperation, support, and input throughout the study: STEERING COMMITTEE Sue Seibert, Town of Aurora Jason Unger, Town of Newmarket Ruth Coursey, Town of East Gwillimbury James Morning, Township of King Andrew McNeely, Town of Whitchurch-Stouffville M. Craig Piper, Regional Municipality of York Peter Roberts, Ontario Ministry of Agriculture and Rural Affairs Ian Buchanan, Ontario Ministry of Natural Resources Steve Maude, Ontario Ministry of the Environment Karen Jones, Ontario Ministry of the Environment Reinie Vos, Lake Simcoe Region Conservation Authority PUBLIC ADVISORY COMMITTEE: Brian Clarke James Elliott Robert Elliott Aimee Garcia David Lanziner Willard Petersen Roger Routledge Bob Taylor EAST HOLLAND RIVER SUBWATERSHED STUDY TEAM Lake Simcoe Region Conservation Authority Michael Walters Andrea Ferguson Jones Reinie Vos David Lembcke Andrea Gynan Stefan Romberg Geoff Peat Graeme Davis Tom Hogenbirk Hydrogeology Consultants S. N. Singer, C. K. Cheng & I. Solovykh Environmental Monitoring and Reporting Branch Ontario Ministry of the Environment Special thanks to the summer and co-op students for their help throughout the project: Tim Phaneuf Steve Rennick Aaron Wood Matthew Purvis Joanna Parsons Claire Bradley TABLE OF CONTENTS Executive Summary. i PART I INTRODUCTION ................................................ 1 Chapter 1 Background ............................................. 1 Chapter 2 Watershed Planning Principles ............................ 3 Chapter 3 The East Holland River Subwatershed ..................... 5 Chapter 4 The History of the East Holland River Subwatershed ....... 10 Chapter 5 Study Goals and Objectives ............................. 18 PART II THE HEALTH OF THE EAST HOLLAND RIVER SUBWATERSHED 21 Chapter 6 Land ................................................... 22 6.1 Natural Corridors ......................................... 22 6.2 Wildlife Habitat ........................................... 25 6.3 Aggregate Resources ..................................... 31 6.4 Woodlands .............................................. 31 6.5 Wetlands, Environmentally Significant Areas & ANSI’s .......... 36 Chapter 7 Water ................................................... 44 7.1 Water Quality ............................................ 44 7.2 Hydrogeology ............................................ 77 7.3 Water Quantity ........................................... 82 7.4 Aquatic Environment ...................................... 93 Chapter 8 Community ............................................ 108 8.1 Recreation & Trails ...................................... 108 8.2 Natural Hazards ......................................... 113 8.3 Urban Growth ........................................... 115 8.4 Infrastructure ............................................ 119 PART III DIRECTIONS FOR MANAGEMENT ............................. 122 Chapter 9 Directions for Strategy Development ..................... 122 9.1 Summary of Key Issues ................................... 122 9.2 Developing an Environmental Screening Map ................ 128 9.3 Monitoring .............................................. 129 GLOSSARY REFERENCES APPENDICES Appendix A: Species Lists LIST OF FIGURES Figure 2.1 The Hydrologic Cycle ............................................. 3 Figure 3.1 Map of Study Area ............................................... 6 Figure 3.2 Digital Elevation Model of the East Holland River Subwatershed ........ 8 Figure 3.3 Soils ........................................................... 9 Figure 4.1 Population Growth in the East Holland River Subwatershed ............ 17 Figure 6.0 East Holland River Catchments ................................... 22 Figure 6.1 Land Use ...................................................... 24 Figure 6.2 Land Use Per Catchment ........................................ 25 Figure 6.3 Forest Corridor, Wetlands and the Oak Ridges Moraine .............. 27 Figure 6.4 Forest Interior .................................................. 29 Figure 6.5 Aggregate Resources ........................................... 33 Figure 6.6 Forest Stand Size .............................................. 35 Figure 6.7 Environmentally Significant Areas and Areas of Natural and Scientific Interest ........................................................ 41 Figure 6.8 Terrestrial Issues by Catchment ................................... 43 Figure 7.1 Provincial Water Quality Network Sample Station Locations ........... 46 Figure 7.2 Total Phosphorus Concentrations ................................. 49 Figure 7.3 Total Nitrogen Concentrations .................................... 51 Figure 7.4 Total Iron Concentrations ......................................... 53 Figure 7.5 Total Aluminum Concentrations ................................... 54 Figure 7.6 Total E. coli Concentrations ...................................... 56 Figure 7.7 Urban Hydrologic Cycle .......................................... 58 Figure 7.8 Sewersheds and Stormwater Management Ponds in Aurora ........... 66 Figure 7.9 Sewersheds and Stormwater Management Ponds in Newmarket ....... 68 Figure 7.10 Water Quality Issues by Catchment ................................ 76 Figure 7.11 Groundwater Recharge Areas .................................... 80 Figure 7.12 Streams Surveyed .............................................. 87 Figure 7.13 Erosion Ratings for Sites in the East Holland River Subwatershed ...... 91 Figure 7.14 Fisheries Sampling Data ........................................ 96 Figure 7.15 Aquatic Issues by Catchment .................................... 107 Figure 8.1 Recreation Areas .............................................. 109 Figure 8.2 Existing and Proposed Trail System .............................. 111 Figure 8.3 Fill and Flood Regulated Areas .................................. 114 Figure 8.4 History of Urban Growth ......................................... 118 Figure 8.5 Infrastructure .................................................. 120 LIST OF TABLES Table 7.1 Sites by Municipality . 89 Table 7.7 Selected Water Quality Parameters and their Significance . 99 Table 8.1 Projected Urban Growth . .116 Table 9.1 Resource Factor Interconnections . .126 State of the Watershed Report Executive Summary Introduction and Goals The Holland River watershed is located in the southwest corner of the Lake Simcoe watershed. It is composed of two major tributaries, the East Holland and the Holland\Schomberg Rivers. The East Holland River is the smaller of the two areas draining approximately 243 km2 or 41% of the total Holland River Subwatershed area. The East Holland River Subwatershed is located almost entirely with the Regional Municipality of York. It contains portions of the Municipalities of Whitchurch-Stouffville, King, East Gwillimbury, Georgina, Newmarket and Aurora. There is a small portion of the south-east section of the Subwatershed that lies in the Township of Uxbridge in the Regional Municipality of Durham. Human activities within the Subwatershed have had a significant impact on the health of the ecosystem. In addressing the current health of the Subwatershed and developing a strategy for the future it was important that a balance be found between the environmental health of the Subwatershed and future urban growth. To this end two guiding principals were adopted, they are: C To Protect What Is Healthy, and C To Rehabilitate What Is Degraded. The Health of the East Holland River Subwatershed Natural features and functions of the Subwatershed were divided into three categories for detailed investigation being Land, Water and Community. Land A wide range of terrestrial habitats were examined and their role in offering a variety of habitats for wildlife, providing resources and recreational opportunities for humans and for maintaining the aesthetic and biological quality of the Subwatershed as a whole. Overall it was found that terrestrial habitats in the Subwatershed are highly fragmented and a mere remnant of what existed prior to settlement in the region. Species that are sensitive to habitat size and shape were found to be limited to particular areas or not found at all within the Subwatershed. Furthermore, the rapid urbanization of the Subwatershed over the past few decades continues to put pressure on these remaining terrestrial habitats. State of the Watershed Report: East Holland River Subwatershed LAKE SIMCOE REGION CONSERVATION AUTHORITY i Water Four factors were considered that relate to water in the East Holland River Subwatershed, including Water Quality, Hydrogeology, Water Quantity and Aquatic Habitat. Water quality in the East Holland River was found to be poor. However, when compared to historic data an improvement in water quality over time could be seen. One major source of pollution to the river was found to be from urban areas through stormwater runoff. Three major aquifer complexes were identified in the hydrogeological analysis of the Subwatershed. These aquifers are responsible for not only providing a groundwater