1. Flood Forecasting and Warning Vienna Flood Model
Presentation to Town of Tillsonburg
July 13, 2009
Heather Surette
Manager of Watershed Services

2. Nanticoke Creek on Thompson Road February 12, 2009
Overview
Background
Role of Conservation Authority
Vienna Flood Model
History
Approach
Application
Next Steps
Summary
Nanticoke Creek on Thompson Road February 12, 2009

3. History of Flooding
October 1954 Hurricane Hazel passed into southern Ontario.
81 people died
Damages estimated at $25 M ($180 M current dollars)

4. Flooding Contributing factors (e.g. ice jams, rainfall)
Major cause spring snowmelt
‘Flood plains’ or ‘flood hazard lands’
Flood plains managed to protect residents
Occupied floodplains = risky business
Vienna
February 13, 2009

5. Flood Management Prevention (e.g. land use policies)
Protection (e.g. dams, dykes)
Emergency Preparedness and Response
Emergency response plans
Mitigation strategies
Specific hazard identification and response (e.g. floods)
Vienna
February 12, 2009

6. Role of Conservation Authorities (CAs)
Ontario Ministry of Natural Resources (MNR) and CAs are responsible for forecasting where and when flooding is likely to occur and issuing flood warnings.
Monitor watershed conditions including snow conditions, precipitation and flows to aid in forecasting and warning.
Advance warning of an impending flood allows municipalities to put emergency response plans into operation, and notifies the public of developing or ongoing unsafe river and lake conditions and allows individuals to take precautions.
The purpose of the system is to minimize flood damage and loss of life.

7. Role of CA’s
Conservation Authorities generally issue three different types of flood warnings:
High Water Safety Bulletin
Flood Advisory
Flood Warning
Sandusk Creek
February 12, 2009

8. Flooding in LPRCA’s Watershed
Municipality of Bayham
Winter/Spring 2008
Winter/Spring 2009 significant flooding
No fatalities
Minor damage
Big Otter Creek near Port Burwell

9. Village of Vienna Located in Big Otter Creek watershed
Flooding in 2008/09
Infrastructure
Sanitary sewers
Roads
Bridges
Residences and business in flood plain

10. Vienna Flood Model History LPRCA and Bayham partnership
LPRCA Comprehensive Study
Impact analysis
Detailed mapping
Effectiveness monitoring

11. Vienna Flood Model Approach Computer model to determine water levels
Simulation of flows and ice jams
Statistical data analysis
Army Corps of Engineers model

13. Vienna Flood Model Application Stages of flooding
Identification of vulnerable infrastructure
Mapping
Model application
Model accuracy analysis
Marking of bridges
Information distributed to residents
Development of partnerships

14. Flood Stages Mapped

15. Vienna Flood Model Next Steps
Defined agency roles and responsibilities
Communication plan to improve interagency consultations
Model upper reaches of Big Otter Creek
Ongoing refinement
Ice Jam Port Burwell February 12, 2009

16. Flooding at Bailey Bridge
Summary
Improved communications between agencies
Emergency response mitigation strategies
Enhanced emergency management programs
Enhanced profile of LPRCA-Municipal partnership
Reduces potential for negative environmental impact
Flooding at Bailey Bridge