Thompson Creek Flood Study Report - City of Peterborough

Thompson Creek Detailed Flood Reduction Study
City of Peterborough
Letter of Transmittal
ACKNOWLEDGEMENTS
TABLE OF CONTENTS
1.0 INTRODUCTION...............................................................................................................1
1.1 BACKGROUND .............................................................................................................1
1.2 CLASS ENVIRONMENTAL ASSESSMENT PROCESS .........................................................3
2.0 PHASE 1 – PROBLEM OR OPPORTUNITY.................................................................8
2.1 DEFINITION OF STUDY AREA .......................................................................................8
2.2 IDENTIFICATION OF THE PROBLEM ...............................................................................8
2.3 PROBLEM STATEMENT.................................................................................................8
3.0 PHASE 2 – EXISTING ENVIRONMENTAL CONDITIONS.....................................10
3.1 GENERAL...................................................................................................................10
3.2 SUMMARY OF AVAILABLE INFORMATION ..................................................................10
3.2.1 Previous Studies...........................................................................................10
3.2.2 Available Data and Data Gaps....................................................................13
3.3 NATURAL ENVIRONMENTAL RESOURCES...................................................................15
3.3.1 Fish Community and Fish Habitat...............................................................15
3.3.2 Terrestrial Features: Wetlands, Vegetation and Wildlife............................18
3.3.3 Fluvial Geomorphology...............................................................................23
3.3.4 Water Quantity Characteristics ...................................................................28
3.3.5 Water Quality Characteristics .....................................................................29
3.3.6 Surficial Soils/Geology/Hydrogeology ........................................................29
3.4 SOCIO-ECONOMIC ENVIRONMENT .............................................................................30
3.4.1 Existing Land Use........................................................................................30
3.4.2 Future Land Use ..........................................................................................34
3.5 SUMMARY OF EXISTING ENVIRONMENTAL CONDITIONS ............................................34
4.0 PHASE 2 – EXISTING CONDITIONS: FLOOD VULNERABILITY......................37
4.1 GENERAL...................................................................................................................37
4.2 SUMMARY OF AVAILABLE FLOOD RELATED INFORMATION .......................................37
4.2.1 Flood Reduction Master Plan......................................................................37
4.2.2 Existing Flood Plain Mapping.....................................................................39
4.2.3 Flow Monitoring ..........................................................................................39
4.3 EXISTING DRAINAGE/STORMWATER MANAGEMENT SYSTEM .....................................43
4.3.1 Thompson Creek Drainage Area .................................................................43
4.3.2 Local Drainage To Otonabee River.............................................................44
4.4 MODELLING CHARACTERISTICS OF MAJOR/MINOR SYSTEMS ....................................45
4.4.1 OTTHYMO Modelling of Thompson Creek Drainage Area ........................45
4.4.2 HEC-RAS Modelling of Thompson Creek....................................................49
4.4.3 OTTSWMM Modelling of Local Drainage Systems.....................................50
4.5 SIMULATION OF FLOOD VULNERABILITY DESIGN EVENTS.........................................54
4.5.1 Definition of Design Rainfalls .....................................................................54
4.5.2 Results of Thompson Creek Watercourse Simulations ................................58
4.5.3 Results of Local Drainage Systems Simulations..........................................65
14-06605-01-W01 City of Peterborough i