Let them drink seawater
‘‘If a quake happens, we know where to go, we know how to go ...’’ Ulvi Salayev Wellington Water project director
When the big one hits, Wellingtonians could find themselves drinking seawater.
Container-sized desalination plants, emergency piping flown from Japan, and ute-carried water bladders are three of the strategies being looked at to supply a city that could realistically find itself without mains water for 100 days.
The ideas were not fairytalestuff, said Wellington Water project director Ulvi Salayev.
‘‘From a water-supply perspective, the fact that we have a linear network running along a faultline ... makes us very vulnerable.’’
The measures are being investigated as part of the community infrastructure resilience project – a $12 million joint initiative between central government and five of the region’s councils.
Discussions were already under way with CentrePort and Wellington Airport to decide locations for the desalination plants, which would probably be flown to New Zealand within 48 hours of a big quake, Salayev said.
‘‘Rather than buying them now and having them rusting away somewhere in a depot, we will establish some kind of contractual arrangement.
‘‘We will go to the world market, and go to some suppliers, and make sure their product is compatible with our network.’’
Even with the ability to treat a million litres of seawater daily, the plants would not be enough on their own.
Wellington’s life-water flows through a pipe running beside a faultline on State Highway 2. If that pipe fractured, the city had reserves for only 19 hours of regular use.
Its CBD and eastern suburbs could expect to be without water for 100 days.
Salayev said all Wellington residents were expected to look after themselves for the first seven days, before emergency measures could be deployed.
That meant having 20 litres per person per day. For a family of four, Salayev said the household should have at least one 200-litre storage tank – preferably two.
Should the city’s piping be destroyed, Salayev’s team are in the process of buying and distributing large water bladders, which would be distributed to prearranged community water stations.
The goal is to have no homes in the capital situated more than a kilometre from such a station. Some bladders would be mounted on utes to reach more isolated communities. They would be filled at a variety of sites, including streams, land-based bores and reservoirs.
These might include the city’s proposed 35 million-litre Prince of Wales reservoir, which will be going for planning consent in midSeptember.
‘‘If a quake happens, we know where to go, we know how to go, who our suppliers are, and that it will work and has been tested – so we can just push a button on it,’’ Salayev said.
Above-ground piping, likely to be flown in by military aircraft from Japan, was needed in case the city’s pipes were compromised.
‘‘One of the assumptions we have made is we cannot rely on underground pipes,’’ he added.
Work was underway to boost Wellington’s reserves, with targets to have two weeks’ worth of water stockpiled, in order to buy time before other systems came online.