Characterization of Ottawa’s Watersheds: An Environmental Foundation Document with Supporting Information Base 1-1 Characterization of Ottawa‟s Watersheds, 2011 March TABLE OF CONTENTS 1 INTRODUCTION ..................................................................................................... 1-9 1.1 PURPOSE ....................................................................................................................... 1-9 1.2 BENEFITS .................................................................................................................... 1-10 1.3 APPROACH .................................................................................................................. 1-10 2 TOPOGRAPHY, GEOLOGY, AND SOILS ........................................................... 2-1 2.1 TOPOGRAPHY ................................................................................................................ 2-1 2.1.1 General Characteristics ............................................................................................. 2-1 2.1.2 Valley Lands and Escarpments .................................................................................. 2-1 2.2 GEOLOGY AND SOILS .................................................................................................... 2-8 2.2.1 Bedrock and the Formation of Surficial Geology ...................................................... 2-8 2.2.2 Physiographic Units and Surficial Geology ............................................................ 2-10 2.2.3 Soils ........................................................................................................................... 2-17 3 CLIMATE .................................................................................................................. 3-1 3.1 SEASONALITY ............................................................................................................... 3-1 3.2 TEMPERATURE .............................................................................................................. 3-2 3.2.1 Annual Trends ............................................................................................................. 3-2 3.2.2 Seasonal Trends ......................................................................................................... 3-2 3.2.3 Heating and Cooling Needs ....................................................................................... 3-4 3.3 PRECIPITATION ........................................................................................................... 3-10 3.3.1 Annual and Seasonal Accumulation ........................................................................ 3-10 3.3.2 Frequency of Multi-day Rainfall Accumulations ..................................................... 3-10 3.3.3 Extended Wet and Dry Periods ................................................................................ 3-12 3.4 LONG-TERM TRENDS .................................................................................................. 3-25 4 HYDROLOGY ........................................................................................................... 4-1 4.1 STREAM FLOWS ............................................................................................................ 4-1 4.1.1 Major Rivers and Streams ......................................................................................... 4-1 4.1.2 Watershed Stream Flows ..................................................................................... 4-2 4.2 GROUNDWATER ............................................................................................................ 4-7 4.3 WATER BALANCE ......................................................................................................... 4-8 4.4 WATER QUALITY .......................................................................................................... 4-9 4.4.1 Reference Chemistry: A Reflection of Watershed Geology ....................................... 4-9 4.4.2 Overview of Water Quality ...................................................................................... 4-12 4.5 WATER TEMPERATURE ............................................................................................... 4-20 1-2 Characterization of Ottawa‟s Watersheds, 2011 March 5 LAND USE ................................................................................................................. 5-1 5.1 GENERAL CHARACTERISTICS ........................................................................................ 5-1 5.2 IMPERVIOUS COVER ...................................................................................................... 5-6 5.3 STORMWATER MANAGEMENT .................................................................................... 5-11 5.4 AGRICULTURE ............................................................................................................ 5-13 5.4.1 Drainage ................................................................................................................... 5-13 5.4.2 Level and Nature of Agricultural Activity ................................................................. 5-16 6 TERRESTRIAL AND AQUATIC ECOLOGY ...................................................... 6-1 6.1 TERRESTRIAL ECOLOGY ............................................................................................... 6-1 6.1.1 Wooded Areas ............................................................................................................ 6-1 6.1.2 Wetlands ..................................................................................................................... 6-7 6.2 AQUATIC HABITAT ..................................................................................................... 6-10 6.2.1 Water Column .......................................................................................................... 6-10 6.2.2 Physical Structure .................................................................................................... 6-12 7 HIGHLIGHTS OF WATERSHED FUNCTION ................................................... 7-1 7.1 GEOLOGY, GROUNDWATER, LAND COVER, LAND USE ................................................. 7-1 7.2 PERMEABILITY OF OVERBURDEN AND SEASONAL TRENDS IN FLOWS ........................... 7-2 7.3 GEOLOGY AND SURFACE WATER CHEMISTRY .............................................................. 7-3 7.4 WATERSHED RESPONSE TO ALTERATIONS IN DRAINAGE .............................................. 7-5 7.4.1 Alterations in Drainage in Developed Areas ............................................................. 7-5 7.4.2 Alterations in Drainage in Agricultural Areas .......................................................... 7-5 7.5 WATER QUALITY AND LAND USE ................................................................................. 7-6 7.6 ALTERATIONS IN VEGETATION COVER AND HYDROLOGY ............................................ 7-6 7.7 INFLUENCES ON AQUATIC HABITAT.............................................................................. 7-6 8 RECOMMENDATIONS........................................................................................... 8-1 8.1 TERRESTRIAL SYSTEM WORK ....................................................................................... 8-2 8.2 AQUATIC SYSTEM WORK .............................................................................................. 8-2 8.3 BEST MANAGEMENT PRACTICES WORK ....................................................................... 8-4 8.4 INFORMATION BASE AND REPORTING ........................................................................... 8-4 8.5 PROPOSED CANDIDATE REFERENCE SUBWATERSHEDS ................................................. 8-7 9 INFORMATION SOURCES .................................................................................... 9-1 1-3 Characterization of Ottawa‟s Watersheds, 2011 March LIST OF TABLES Table 1-1 Typology of Information on Watersheds and Minor Watersheds ................................... 1-12 Table 1-2 Typology of Maps in Appendix A ................................................................................... 1-12 Table 1-3 Sources of Data and Information ..................................................................................... 1-13 Table 2-1 Subwatersheds with the Longest Valleys and Largest Elevation Change ......................... 2-3 Table 2-2 Subwatersheds with the Longest Escarpments and Largest Elevation Change ................. 2-3 Table 2-3 Characteristics of Valley Lands and Escarpments by Minor Watershed........................... 2-7 Table 2-4 Bedrock Type by Subwatershed ........................................................................................ 2-9 Table 2-5 Composition of Physiographic Units in Terms of Geological Deposits .......................... 2-12 Table 2-6 Genesis and Primary Materials in Geological Deposits .................................................. 2-13 Table 2-7 Physiographic Units by Watershed and Minor Watershed .............................................. 2-14 Table 2-8 Permeability of Geological Deposits ............................................................................... 2-15 Table 2-9 Depth and Permeability of Overburden by Watershed and Subwatershed ...................... 2-16 Table 2-10 Soil Capability for Agriculture Classes with Limiting Factors ...................................... 2-18 Table 2-11 Agriculture Soil Capability Class