Risk Mitigation following Canterbury Earthquakes
Jim Palmer Chief Executive Waimakariri District Council Risk Mitigation – Two Ideas
• Risk Assessment and Financing
Strategy
• Risk–based Reticulation Renewals Waimakariri District
Hurunui District
Waimakariri District
Christchurch City
Selwyn District Banks Peninsula
Our Challenge We’ve withstood one major event and it cost $127M – can we withstand another one?
. We are a net-debt, high-growth Council with few realisable assets
. The Alpine Fault failure is ‘overdue’ with a 30% chance within 50 years…. and we have other natural hazard risks
Our Response
Developed a Risk Assessment
and Financing Strategy Risk Assessment and Financing Strategy relating to Considered largest natural risks Major Natural Disasters - earthquake, flood, tsunami
November 2014
Our Biggest Risk Our Response
. Guestimated what the damage might be . Ground-truth it against the 2010 event . Considered funding strategy, both with and without insurance being available . Assessed impact on net debt & affordability . Developed as policy: . Limits for debt . Priority list for asset replacement
Council Funding Position with Crown Support and Insurance Estimated Crown/NZTA Insurance Council Share Reinstatement funding funding
Cost $M $M $M $M Above-ground Infrastructure and 30 0 30 0 Buildings
Below-ground Infrastructure 67 40 27 0
Roading 40 28 12
Reserves 10 0 0 10
Emergency Response/repairs 20 15 0 5
Community Support 5 0 0 5
Total 172 83 57 32 Debt Limits - borrowing as % of operating revenue Debt Limits with Headroom Outcomes . Gives confidence the consequences of major events can be accommodated . Demonstrates prudent management in terms of debt levels and affordability . Provides priority for asset reinstatement
Risk-based Reticulation Renewals
• Reticulation renewals were based on age, condition, and performance.
• Now, we use a risk-based approach
Waimakariri DC – Renewals Profile
VULNERABILITY … TO LIQUEFACTION
Location relative to hazard is critical.
IT’S NOT JUST EARTHQUAKES
Risk-based Reticulation Renewals
Considered . The burst history of the Water mains & CCTV footage
. The remaining useful life
. The vulnerability, made up of: . Location . Material ductility . Jointing method
. Criticality
Waimakariri DC – Renewals Approach Wastewater: • CCTV inspection of ~2% network per annum based on risk profile • Risk score (renewals priority score) to schedule preliminary renewal programme • Renewal method determined from criteria
Likelihood Score Consequence Risk
CCTV score Blockage history Vulnerability x Score = Score
Water: • Burst history and pipe condition recorded • Risk score (renewals priority score) to schedule preliminary renewal programme
Likelihood Score Consequence Risk Remaining Blockage history Vulnerability x Score = Score useful life Risk-Based Reticulation Renewals Location Diameter Material Criticality Vulnerability Remaining Risk Score (mm) Useful Life Sewell St, 375 Asbestos AA Extreme 27 6500 Kaiapoi Cement Holland Dr, 100 Polyethylene C Medium 15 248 Kaiapoi Outcomes
. Renewal strategy reflects risk . Mains have lower chance of failure . More resilient in future disasters . Quicker return of services to the majority of people
So… two ideas
• Risk Assessment and Financing Strategy
• Risk–based Reticulation Renewals
THANK YOU