Flood Risk Management Flood Forecasting and Warning Program and Flood Risk Management Projects Presented by: Rebecca Elliott, P.Eng Flood Risk Management Engineer

Friday Forum January 25, 2019 Presentation Outline

• History of TRCA • Flooding 101 • Flood Forecasting and Warning Program • Flood Risk Management Projects • Flood Risk Assessment and Ranking Project • Toronto Islands Characterization and Risk Assessment • Works Influenced by the Flood Characterization Project (Next Steps) • Recommendations

The information contained in this presentation is copyright © Toronto and Region Conservation Authority

Toronto and Region Conservation Authority 2 HISTORY OF TRCA

Toronto and Region Conservation Authority 3 About the TRCA

• Conservation Authorities were established in 1946 under the Conservation Authorities Act

“To ensure the conservation, restoration and responsible management of hydrological features through programs that balance human, environmental and economic needs.”

• Several smaller CA’s made up what is now known as Toronto and Region Conservation Authority

• Then in October of 1954 everything changed…..

Toronto and Region Conservation Authority 4 Hurricane Hazel: October 15-16, 1954

Toronto and Region Conservation Authority 5 Hurricane Hazel

Toronto and Region Conservation Authority 6 History of Flood Control

• Metropolitan Toronto and Region Conservation Authority (MTRCA) was formed in 1957.

• Amendment to CA Act to acquire lands for recreation and conservation purposes

• 1959 Plan for Flood Control and Water Conservation 1. Property acquisition 2. Control structures: dams and channels – move the water quickly 3. Land use planning

Toronto and Region Conservation Authority 7 1. Property Acquisition

Toronto and Region Conservation Authority 8 Map of TRCA Greenspaces

Toronto and Region Conservation Authority 9 2. Flood Control Infrastructure

Toronto and Region Conservation Authority 10 TRCA Flood Control Infrastructure Today

Toronto and Region Conservation Authority 11 Flood Control Infrastructure - Dams

Claireville Dam, Brampton G.Ross Lord Dam, Toronto

Toronto and Region Conservation Authority 12 Flood Control Infrastructure - Channels

• Built to quickly convey floodwaters away from a risk area • Results in ‘flashy’ watersheds • Can sometimes exacerbate the situation downstream because of loss of stream length and storage • Negative ecological impacts

Toronto and Region Conservation Authority 13 3. Land Use Planning

Living City Policies for Planning and Development in the watersheds of the Toronto and Region Conservation Authority

Toronto and Region Conservation Authority 14 WATERSHEDS

Toronto and Region Conservation Authority 15 TRCA’s Jurisdiction and Watersheds

When rain falls on our watersheds, that water makes its way into our local rivers and streams, which drain to Lake Ontario Toronto and Region Conservation Authority 16 Flashy Watersheds

Toronto: • so flashy, little lead time Calgary: • much larger drainage area, 12 hour lead times

Toronto and Region Conservation Authority 17 FLOODING 101

Toronto and Region Conservation Authority 18 Floods Happen….often

Toronto and Region Conservation Authority 19

What is Flooding?

Toronto and Region Conservation Authority 21 Types of Flooding - Riverine Riverine flooding: the partial or complete inundation of the floodplain, caused by bank overtopping when the conveyance capacity of rivers and streams is exceeded

Toronto and Region Conservation Authority 22 Types of Flooding - Urban Urban flooding: the inundation of a built environment, caused by rainfall overwhelming the capacity of drainage systems, such as storm sewers and roads.

Toronto and Region Conservation Authority 23 Riverine and Urban Flooding

Riverine Flooding falls under the Urban flooding is the responsibility of mandate of Conservation Authorities. municipalities.

Toronto and Region Conservation Authority 24 What Causes Flooding?

Toronto and Region Conservation Authority 25 Why is it getting worse?

1. Climate Change 2. Land use changes

3. Increased Exposure to Risk

Toronto and Region Conservation Authority 26 Who Deals with Floods?

Municipalities  Deal with all major emergencies and are responsible for the welfare of their residents

Ministry of Natural Resources and Conservation Authorities Forestry (MNRF), on behalf of the  Operating a province forecasting and  May coordinate a response warning system in support of municipal action.

Toronto and Region Conservation Authority 27 Municipality Role & Responsibilities 1. Notify appropriate municipal officials, departments and agencies in accordance with their municipal emergency plan. 2. Determine the appropriate response to a flood threat and, if warranted, deploy municipal resources to protect life and property. 3. If required, declare a flood emergency and implement their emergency response plan. 4. Request provincial assistance under the Emergency Management and Civil Protection Act, if municipal resources are inadequate to respond to the emergency. 5. Maintain liaison with Conservation Authority Flood Duty Officers.

Toronto and Region Conservation Authority 28 Provincial Role

1. Operate and maintain a provincial forecasting and warning system to alert MNRF District Offices and Conservation Authorities of potential meteorological events that could create a flood hazard. 2. Maintain communications with MNRF District Offices and Conservation Authorities regarding the status of provincial flood potential. 3. Receive messages from CAs, MNRF Districts and other agencies and provide analysis and information that is used to guide the MNRF’s response to a flood. 4. Assists the MNRF Districts where CAs do not exist in the preparation of river response forecasts, daily planning cycle, and the monitoring of local storm conditions.

Toronto and Region Conservation Authority 29 Individuals and Homeowners

1. Make an emergency plan with loved ones 2. Make an emergency kit or To-Go-Bag 3. Understand your risks 4. Prepare for these risks 5. Reduce likelihood of flood damage 6. Follow directions of local emergency responders

Toronto and Region Conservation Authority 30 Conservation Authorities Role: Flood Forecasting and Warning Program • Monitor watershed and weather conditions and operate a flood forecasting system • Issue Flood Messages • Operate Conservation Authority dams and flood control structures • Provide advice to municipalities • Maintain communications with municipalities and other agencies

Toronto and Region Conservation Authority 31 Monitoring Network

• Rainfall and water level data is collected throughout TRCA and is transmitted in real-time

• Stream water level • Precipitation amounts • Reservoir water levels

LOCATION / York Peel City of Durham TOTAL GAUGE TYPE Region Region Toronto Region Stream Gauges 0 5 8 1 14 Rain Gauges 9 6 5 1 21

Reservoir Gauges 2 1 1 0 4 TOTAL 11 12 14 2 39

Toronto and Region Conservation Authority 32 Monitoring Network

Toronto and Region Conservation Authority 33 TRCA’s Flood Monitoring Website www.trcagauging.ca

Toronto and Region Conservation Authority 34 TRCA Flood Message Types

No flood conditions exist

High flows, unsafe banks, melting ice or other factors that could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc. Flooding is not expected.

Early notice of the potential for flooding based on weather forecasts calling for heavy rain, snow melt, high wind or other conditions that could lead to high runoff, cause ice jams, lakeshore flooding or erosion.

Flooding is possible in specific watercourses or municipalities. Municipalities, emergency services and individual landowners in flood-prone areas should prepare.

Flooding is imminent or already occurring in specific watercourses or municipalities.

Toronto and Region Conservation Authority 35 TRCA Flood Messages

@TRCA_Flood www.trca.ca/flood

Toronto and Region Conservation Authority 36 When is “Flooding Season”?

Toronto and Region Conservation Authority 37 Winter/Spring Flooding Winter: 1. Rain-on-snow event 2. Ice jams

Spring: 1. Spring freshet 2. Spring showers

Toronto and Region Conservation Authority 38 Summer Flooding – Convective Thunderstorms

Two types of summer storms: 1. Large scale weather systems with short or long periods of rainfall 2. Short-lived thunderstorms with significant rainfall

Toronto and Region Conservation Authority 39 August 7th, 2018

Toronto and Region Conservation Authority 40 August 7th, 2018

Hilldale Road

Concrete Channel

Toronto and Region Conservation Authority 41 August 7th, 2018

Very localized area received a dumping of rainfall ranging from 30mm to over 100mm in a span of 2.5 hours.

Toronto and Region Conservation Authority 42 Fall Flooding - Hurricanes

Toronto and Region Conservation Authority 43 Flood Risk Management Projects

1) Flood Risk Assessment and Ranking Project

2) Toronto Islands Characterization and Risk Assessment

3) Flood Remediation Studies

4) Outreach Program

Toronto and Region Conservation Authority 44 LAKE ONTARIO FLOODING SITUATION 2017

Toronto and Region Conservation Authority 58 The Lead Up • Prior to April 2017 there was no record of any Shoreline Hazard warning message issuance. • Primary focus on Riverine Flooding

Toronto and Region Conservation Authority 59 The Situation: Lake Ontario Flooding 2017

• First notice of high lake level issues in mid-April at the Ashbridges Bay beach volleyball courts

Source: Toronto Star; Tues April 11, 2017 https://www.thestar.com/news/gta/2017/04/11/is-the-ashbridges-bay-beach- disappearing.html

Toronto and Region Conservation Authority 60 TRCA Response

• Many groups, and dozens of people, in TRCA helped with the response and recovery during and after the flooding • The Flood Risk Management Team was only a very small portion of people helping

Toronto and Region Conservation Authority 61 TRCA Response: FRM Team

• Began referencing shoreline impacts in flood messages on April 27th

• A special statement was posted on May 2nd

Toronto and Region Conservation Authority 62 Lake Ontario Flooding 2017 Impacts

Toronto Waterfront Parks • Erosion, damage and debris accumulations

Toronto and Region Conservation Authority 63 Lake Ontario Flooding 2017 Impacts

Toronto Islands • 30 Businesses • 2 Schools

Toronto and Region Conservation Authority 64 Lake Ontario Flooding 2017 Impacts

Toronto Islands • 800 Residents

Toronto and Region Conservation Authority 65 Lake Ontario Flooding 2017 Impacts

Toronto Islands • Approximate Net Loss from April to July 2017 = $4.9M

Toronto and Region Conservation Authority 66 WHAT’S CHANGED SINCE THE LAKE ONTARIO 2017 FLOODING EVENT?

Toronto and Region Conservation Authority 67 what’s new after 2017? 1. Early warning • ILOSLRB weekly briefings • ECCC Great Lakes Water Levels Information Updates • MNRF flood messages for Static Water Levels

2. Data sources • Fisheries and Oceans Canada hourly water levels • MNRF Great Lakes Operational Storm Surge System (GLOSS) • ECCC Experimental Water Level and Waves Forecasts for Lake Ontario

3. Procedures, tools, and projects • Interim thresholds for issuance of Lake Ontario Shoreline Hazard Warning • Lake Ontario Shoreline Hazard Warning website updates • Toronto Islands Flood Characterization and Risk assessment project

Toronto and Region Conservation Authority 68 1. Early Warning

ILOSLRB weekly briefings • Summary of water levels, inputs and outputs to Lake Ontario

• Puts current conditions into context

• Forecast of what we could expect

Toronto and Region Conservation Authority 69 ECCC Great Lakes Water Levels Monthly Information Updates

• Summary for all of the great lakes

• 3 month and 6 month average net basin and net total supplies

• Puts conditions into context

• Great for reference purposes

Toronto and Region Conservation Authority 70 MNRF Flood Messages for Static Lake Levels

• Interim strategy for provincial shoreline hazard messages (flood outlook, and flood watch) • Province gives Conservation Authorities along the Lake Ontario Shoreline early warning for high lake levels • province utilizes information from the ILOSLRB forecasts and known thresholds of concern from Conservation Authorities

Toronto and Region Conservation Authority 71 2. Data Sources

1. Static Lake Level • Fisheries and Oceans Canada hourly water levels

2. Potential Surge • MNRF Great Lakes Operational Storm Surge System (GLOSS)

3. Wave Height • ECCC Experimental Water Level and Waves Forecasts for Lake Ontario

Toronto and Region Conservation Authority 72 3. Procedures, tools, and projects Interim thresholds for issuance of Lake Ontario Shoreline Hazard Warning

• Prolonged shoreline hazard warning: o Static water level > 75.5m

• Storm-related shoreline hazard warning: o Static water level + surge > 75.1m AND 75th Percentile offshore wave height > 2m

Toronto and Region Conservation Authority 73 Lake Ontario Shoreline Hazard Warning website updates

• Pre-2017: Our messaging focused on our rivers and streams

• Post-2017: There was a need to differentiate between riverine flooding along our rivers and lake flooding along the shoreline

• Current: Flood status widget has been updated to differentiate between watershed conditions and shoreline conditions

Toronto and Region Conservation Authority 74 Toronto Islands Flood Characterization and Risk assessment project

• Funding from Toronto Parks, Forestry and Recreation, and matching funds from Public Safety Canada through the National Disaster Mitigation Program (NDMP) in 2018

• Retained Baird to conduct 4-phase Flood Characterization and Risk assessment (to be completed in early 2019)

Toronto and Region Conservation Authority 75 Summary of Study Deliverables

Risk Scenario Assessment Identify Flood Develop Inundation and Shoreline Mitigation Characterization Response Plan Maps Hazard Options Thresholds

Toronto and Region Conservation Authority 76 Work Influenced by the Flood Risk Assessment and Ranking Project

1) Ongoing Enhancements to the Flood Forecasting and Warning Communications

2) Flood Remediation Studies

3) Outreach Program

Toronto and Region Conservation Authority 77 Using stream gauges to better understand risk areas…

Toronto and Region Conservation Authority 78 Enhancements to the Flood Forecasting and Warning Program

1) Updating messaging to allow for specified areas or structures at risk of flooding

2) Ongoing assessment for additional gauges at the highest priority areas in the jurisdiction

Toronto and Region Conservation Authority 79 Flood Remediation Studies

BlackDixieIntakeBoltonMaltonDowntownFloodVaughanDonPort MillsLands Dundas CreekRemediationRisk5 BermFlood Flood Black Channel BramptonCharacterizationFlood at Remediation Flood Remediation Rockcliffe Protection Flood Study Flood Reduction Yonge Street PhaseMitigationBermStudyCharacterizationProtectionandCreekEnvironmental ElginMitigationEnabling Renewal3 Environmental Mills ProjectEnvironmental Infrastructure Analysis AssessmentRoad with – FloodCity with Vulnerable the AssessmentofStudyAreaProjectCitySpring Mississauga of Environmental MarkhamCreek, Zone 7Assessment • Cluster: Avondale/DixiePickeringBoltonBramptonElginEdgeleyRockcliffeMaltonProgressMarkhamLower Mills- Don – • ClusterDundasVillageCoreCentralVaughanBusinessIndustrialSpring CreekRank: CentrePark 122348 • ClusterCompleted Rank: Marchin 201634528147106 2018

Toronto and Region Conservation Authority 80 Outreach Program Develop and implement an outreach program centralized around informing municipal partners about flood risk, and improving communications prior to, during and following storm events. The scope also includes public information sessions within neighborhoods in the Greater Toronto Area known to be at risk of riverine flooding, as identified through previous flood risk assessment work. Creating awareness of potential flood emergencies to lessen the impact of flooding to these areas, as residents can take preparatory steps to protect themselves and their homes and reduce the risk to life and damage to property caused by flooding.

Toronto and Region Conservation Authority 81 Outreach Program - Timelines

2018 2019 2020

• Finalized workplan, • Preparing materials for • Post-program Analysis schedule and budget muncipalities • Reporting • Hired Flood Outreach • Regional and Municipal • Project Completion by Coordinator meetings March 31, 2020 • Engaging internal and • Finalizing and creating external working groups print materials • Working on determining • Public information key messages sessions/Outreach for • Preparing the Flood Vulnerable communication material Areas in the TRCA jurisdiction

Toronto and Region Conservation Authority 82 Outreach Program - Key Messages

Stay Understand Prepare Informed

Toronto and Region Conservation Authority 83 Questions

Toronto and Region Conservation Authority 84 Thank you

Rebecca Elliott, P.Eng. [email protected]

www.trca.ca/flood @TRCA_Flood

www.trca.ca