Low rainfall puts regional water supply on alert

There was less rain than usual in the region’s main water catchments in October, reinforcing the need to prepare for less water this summer now that we’re down by one storage lake.

Cr Nigel Wilson, Chair of Greater Wellington’s Social and Cultural Wellbeing Committee, says that although Wellington had above average rainfall in October, there was in fact below average rainfall in the Hutt, Wainuiomata and Orongorongo catchments – where Greater Wellington’s main river water sources are located. (Greater Wellington supplies water to Porirua, Wellington, Upper Hutt and Lower Hutt.)

“A dry spring in the water catchments is of concern. It means that we’re more likely to run short of water from rivers if we get a long spell of good weather this summer. And with one water storage lake empty, the risk of water shortages will be even higher,” says Cr Wilson.

A water conservation campaign for the four cities supplied by Greater Wellington kicked off in September, asking people to prepare for less water over the next 2-3 summers while the Stuart Macaskill lakes at Te Marua are upgraded to increase earthquake resistance and boost capacity for our growing population.

While water use across the four cities was also below normal usage during October, Cr Wilson is urging people to remain vigilant as the weather improves. “Nobody wants to see tough water restrictions spoil our summer. But if people start making changes now to save just a bit more water in the coming months it’ll make a difference. And they can be small, easy changes, whether it’s fitting a flow trigger on your hose or fixing leaking taps, pipes and toilets.”

For tips on saving water, see www.gw.govt.nz/water.

Rainfall and riverflow data

October's rainfall and river flows figures for our catchments and rivers were below average:

October 2011 river flows and aquifer level (percentage compared to the long-term October average for each site)
Hutt River (at Kaitoke) – 70%
Wainuiomata River – 82%
Aquifer – 97%

October 2011 rainfall (percentage compared to the long-term average rainfall for each site)
Kaitoke – 93%
Wainuiomata – 70%
Orongorongo – 83%

For more information, please contact our www.gw.govt.nz/water.