Future full of rain, floods, slips
As Wellington shakes off a wild winter which saw cars bobbing in floodwaters and thunderous waves over roads, a worrying picture has been painted: Expect more of it, even planned spending won’t save us, and low-lying areas, be warned.
A report going to the Wellington City Council this week shows the July 17 and 18 storm saw the council’s call centre ‘‘overwhelmed’’ as it took 1400 calls and digital notifications. Wellington Water – in charge of the city’s pipes – responded to 336 incidents.
This included 67 homes that were ‘‘compromised’’ by water – either storm water, waste water, or both. ‘‘It tested our operational capability, and highlighted the risks of habitation in the vicinity of streams and low-lying areas,’’ the council papers say.
The council is already borrowing to make up for a historic lack of investment in pipes that has seen multiple public failures – including sewage onto public streets – but the council papers show that there are areas where increased spending will not help.
‘‘As we plan for more intense rainfall events there is likely to be an increasing focus on insurance and liability.’’
The July storm rainfall was equivalent to a one-in-60-year event in the eastern suburb of Miramar and designing to mitigate for this type of event would mean ‘‘significant investment’’ in pumps. But there was no significant funding for storm water improvements in the council’s long term plan.
‘‘Hotspot areas . . . flood regularly, and climate change will increase the frequency and severity of flooding and slips. In order to mitigate flood risks in future, choices will need to be made.
‘‘While some of these will no doubt involve the upgrading of infrastructure, for some areas this may not be possible or practicable.
‘‘Wellingtonians are going to have to learn to live with more water, and to plan our city accordingly . . . development in the lowest lying areas, adjacent to streams or in former lakes will increasingly be at risk.’’
Wellingtonians could also expect more slips in coming years, the papers show. That July
storm saw homes in the northern suburb of Newlands evacuated by a slip, trees downed, and flooding around the city, including a complex at the bottom of Ngaio Gorge where people there described an ‘‘explosion of water’’ coming through and cars floating in flood waters.
It came just weeks after massive waves pummelled Wellington’s
south coast, forcing the evacuations of some homes, including the weather-hardened residents of Breaker Bay. But, for the wave issue at least, the council is spending now in hopes of a solution.
Residents of the south coast Wellington community Ō whiro Bay have long called for the removal of the wave ramp, a naturally-formed ramp of sand formed against the sea wall that delivers waves over the beach and road then into properties.
The council had waited for proof that moving the ramp would have the desired effect.
Council correspondence now shows that most of the work, including surveying and an environmental assessment, has been done and physical work to remove the ramp will begin by the end of October.