1. Assessing Vulnerability & Climate Change Impacts
Youssef Habboush
January-18-19

2. Outline Background Climate Change Recent Studies
Risk Assessment Information Templates
Moving Forward

3. Who We Are Population Area NS @ 950,000 (2017) NS @ 55,200 km2
403,000 (2016)
5,500 km2
42%
10%

4. HRM @ 5,495 km2 PEI @5,660 km2 Source: HRM IMP Report 2017
PEI 72 Municipalities VS 1 Municipality
HRM deals with infrastructure within Urban, Suburban, and Rural areas. Requiring extensive expertise.

5. Climate Change Assessment
HRM receives mm of rain annually;
Extreme events likelihood on the rise;
Extreme event >200mm in 24hr
16% annual precipitation increase by 2100;
Projections indicate that the current 100yr event will be:
50yr event by 2020
25yr event by 2050
15yr event by 2080

6. Sea Level Rise & High Water
Combination of
Sea level rise
Increasing storm surge
Crustal subsidence (Sinking land)
Extreme Total Sea Level (High Water in Meters) – Halifax
Return Period
2000
2025
2055
2085
2100
10-Year
2.87
3.02
3.30
3.70
3.93
25-Year
2.97
3.12
3.40
3.80
4.03
50-Year
3.04
3.19
3.47
3.87
4.10
100-Year
3.11
3.26
3.54
3.94
4.17
Source: High Water Projected Values Based on Halifax, NS (Richards & Daigle, 2011)

7. Flooding Scenarios Flash Flood
High intensity and short duration (summer thunderstorms)
Heavy Rainfall
>50mm in 24 hours (nor’easters/tropical storms)
Multi-day Accumulation
Rainfall during thaw cycle (run-off along frozen ground)
Storm Surge (Costal high water)
Storm events with high tides (HRM)

8. Water doesn’t differentiate between property lines nor Responsibility
Water doesn’t differentiate between property lines nor Responsibility. It’s a shared problem between all affected parties.

9. Responsibilities Province of Nova Scotia Regulatory authority
Owner of watercourses and some wetlands
Halifax Water
Owner of pipes and ditches
Governed by Utility and Review Board
Halifax Regional Municipality
Manage overland flow from development and municipal lands
Private Property Owner
Maintain private infrastructure and site generated flow

10. Baseline Study
In 2015, HRM and Halifax Water compiled a compendium of known areas prone to flooding within the service boundary.
Initially, over 5700 drainage issue sites were identified.
This list was refined down to 916 sites.
The criteria used to refine the list included:
Work was undertaken to address the issue.
Duplicate sites were removed.
Strictly private property issues were excluded.

11. Baseline Established
The list of 916 sites was further jointly refined by HRM and Halifax Water staff to 30 key sites.
Developing the 30 key sites did consider risk but did not attempt to quantify or measure it.
National Disaster Mitigation Program: Flood Risk Assessment Study
Consolidation and selection of certain sites in conjunction with historical and operational knowledge

12. Figure 1: Overview of HRM NDMP Site Locations
30 Sites
Figure 1: Overview of HRM NDMP Site Locations

13. Study Objectives Develop a top 10 highest priority;
Using the NDMP Risk Assessment Information Template (RAIT) developed by Public Safety Canada.
Develop a preliminary mitigation strategy complete with order of magnitude costs estimates.

14. RAIT Criteria Infrastructure Public Safety Society Economic
Environment
Seasonal Conditions
Return Period Likelihood

15. RAIT - Sample
RAIT Criteria: The assessment considers the impacts of Climate Change in terms of the frequency, duration, and volume of extreme events, and its impact on municipal stormwater systems.

16. Methodology Desktop Research Site Visits Operation Staff Workshops
Risk Assessment Information Template

17. Final Outcome Groupings
Large Natural Watershed Systems
Three Sites
Localized Drainage Infrastructure
Four Sites
Tidal Influenced Systems

18. Sackville Rivers Key Site Characteristics
Large Natural Watershed

19. Sackville Rivers Key Asset Inventory

20. Moving Forward
Capital investment strategy for stormwater infrastructure
Ownership and maintenance of stormwater systems
Land development practices

21. Capital Investment Strategy
NDMP:
Funded by National Disaster Mitigation Program, HRM, and Halifax Water
Next steps
Identify cost sharing of mitigation measures then prioritize and program actions with Council

22. Ownership and Maintenance
Work Management Guidelines developed
Special Technical Committee with emphasis on operations
Next Steps
Continue implementation of Asset Management Programs

23. Land Development Practices
Lot Grading By-law update
NSUARB Stormwater Rate Hearing Concluded
Direction from the Board regarding joint standards that consider quality
New House Construction - Flood Resilient Design Guidelines
Next Steps
Stormwater Management By-law, Joint Standards W/ Halifax Water, and Green Infrastructure / Community Design standards

24. Questions
Source: ESSC Integrated Stormwater Management Policy Presentation December 7,2017