Christchurch’s capacity to keep its water reservoirs filled is likely to be stretched this weekend unless people heed advice to conserve water.
With temperatures in the city tipped to exceed 30 degrees over the next couple of days the city council is concerned high demand for water could impact on the city’s water supply network.
The city council will make a decision on Monday whether to introduce water restrictions.
This means people would only be permitted to use hoses, sprinklers and garden irrigation systems every second day.
“The problem is not that we don’t have enough water. The problem is that when it gets really hot we struggle to get the water through the pipes and into the reservoirs fast enough to meet the high demand,’’ said city council head of three waters and waste John Mackie.
“If we can’t keep the reservoirs filled, the pressure across the network drops. It also leaves us exposed in the event of a fire because having sufficient water in the reservoirs is essential for fire-fighting.
“It is critical we manage demand and give the reservoirs time to replenish. We need everyone to do their bit to cut back on the water they are using because if consumption keeps rising, we will be using water faster than we can fill the reservoirs or move it through the pipes.’’
At the weekend Christchurch used more than half a billion litres of water, which is the most water used over a weekend since January 2009.
On Monday the city used 254 million litres in total – the equivalent of 678 litres for every person in the city.
Mr Mackie said long term the council could put in bigger pipes and build more pump stations and reservoirs to enhance the performance of the water supply network over the summer peak but it would cost lots of money.
“We have to look at the considerable impact on rates that would have compared with asking people to conserve water during the hottest period of the summer,’’ he said.
One easy thing people could do to ease demand on the network was to cut back on watering their lawn and garden.
“If everyone only watered their garden every second day and only after 9pm or before 6am it would significantly ease pressure on the network,’’ Mr Mackie said.