Published 14/11/2017
One year on – and the message is the same. Store water now!
Wellingtonians need to have up to 140 litres each of stored water to help them get through the first seven days following a major earthquake, advises the council-owned water network company Wellington Water. Chief Executive Colin Crampton says home water storage is an urgent issue that people can take action on today.
“It can be difficult for people to imagine the possibility of having no water in the tap or the ability to flush the toilet. This week’s anniversary of the Kaikoura earthquake is a reminder that we cannot be complacent when it comes to looking after ourselves and our whanau.”
“It is a fact of living in our region, where active fault-lines cross our highly populated areas, that around 1,400 kilometres of our water supply pipes are at risk in a significant event.”
Some Wellington suburbs could be without water for more than 100 days after an earthquake of 7.5 or stronger, and the Wellington, Porirua, Lower Hutt, and Upper Hutt City councils are joining forces with central government to develop an above-ground emergency water supply network that will meet community needs from day eight onwards.
“That’s why you should store 140 litres for each person, or 20 litres a day each for seven days,” Mr Crampton says. “It will take time to get the emergency network operating. You’ll also need a plan for making sure your stored water is safe to drink, and for what to do with your toilet waste.”
The above-ground emergency water network will be ready to deploy by the end of June 2018. It will consist of at least 22 water stations which are strategically placed around the region. These stations will fill mobile bladders, which will then be transported to over 300 distribution points in the community where people can collect the water. Distribution points will be established within 500 to 1,000 metres of every home.
Background
- The home water storage recommendation of 20 litres a day is based on guidance from international aid agencies. A minimum of 20 litres every day for every person, provides for drinking, cooking and hygiene. The historical guidance of three litres is for drinking water only.
- Wellington Water supplies water from the Hutt River (at Upper Hutt), the Waiwhetu Aquifer (extracted at Waterloo), and from rivers behind Wainuiomata. That water has to be pumped to all of Upper Hutt, Lower Hutt, Porirua and Wellington. There are 2,000 kilometres of buried water supply pipes. Those supply lines would be broken in places, so the areas furthest from the supply, such as Karori, Newtown, and Miramar would take the longest to reconnect.
- The new water stations will be used to source, treat, and distribute water to Wellington’s communities.
- The community water stations are designed to be mobile – and can be relocated to areas that are still without water.
- For communities that cannot be supplied by groundwater and surface water sites, the emergency water network will be supported by desalination systems to keep water flowing.
- The above-ground emergency water network is a distinct programme to be delivered by June 2018. Wellington Water is working with its client councils to implement a series of network improvement and community initiatives that will progressively improve the resilience of the water supply network over time.
- The proposed new 35 million litre Prince of Wales/Omāroro reservoir will add capacity to Wellington’s water storage network, significantly enhancing resilience to disaster events.
- The exploratory harbour bores project is running tests to see if the water quality and water quantity is suitable for alternative water supply. Drilling is still underway, but depending on results, it could provide a good alternative to building a cross-harbour pipeline.
- From a water supply perspective Christchurch was able to largely ride through the events of 2010 and 2011. This was due to the water supply network being fed by bores distributed throughout the city - a spider’s web style system of bores which is adaptable to faults. Wellington’s system by comparison is dependent on three water sources that feed the network. The restoration times of more than 100 days for some suburbs are a culmination of the fact that the water supply network crosses multiple fault-lines and many customers are a long way away from one of the region’s three water sources.