Shaken, Not Stirred: Water Supply Network Resilience in the Wellington Region

Wellington sits across an active seismic fault line and depends on remote sources for its water supply. With widespread damage expected after a large earthquake, it may be months before a minimal water supply is restored to residents, and even longer before it reaches the tap.

This paper presents a recent study undertaken to identify network vulnerabilities and take water supply resilience to the next level. The study presented a possible timeline for repairs to the bulk network and restoration of supply to each suburb’s reservoir. This highlighted the most critical areas where an alternative supply or storage was needed.

The second aspect of the problem was to get the water to the customers after the reticulation had been shaken. The strategy was to develop a seismically-resilient skeleton network connecting reservoirs and key distribution points. A notable innovation was the use of advanced algorithms to determine optimal locations for public tap stands and identify the most cost-effective critical pipe where strengthening upgrades needed to be focused.

Finally, the study proposed an order of cost for the colossal programme of work involved, and identified risks and opportunities that could significantly alter the final project cost.