Renwick residents warned they may face water restrictions again, as aquifer levels plummet
Renwick residents have been warned to keep an eye on their water use, as water restrictions loom.
For the first time this summer residents' water usage has exceeded the output from the town's wells.
Renwick Smart and Connected chairman John Kelly put out a message during the weekend telling residents restrictions could be reintroduced in the town.
"The [Wairau] aquifer is at a higher level than this time last year, but it's dropping rapidly," Kelly said.
Marlborough District Council operations and maintenance engineer Stephen Rooney confirmed restrictions could be imposed if water in Renwick's wells dropped to within a metre of the pump.
"We are encouraging the Renwick community to keep their demand below 3000 [cubic metres of water per day]," Rooney said.
"Over the weekend they exceeded that."
Since November the water supply has plummeted, but consumption has been steadily rising.
Last summer Renwick escaped water restrictions due to voluntary water conservation practices, and a couple of late summer downpours.
However in previous years the township has had water restrictions, often beginning in December or January and sometimes lasting three or four months.
If demand for water exceeded the output, the pumps could be damaged by air being drawn into the system, Kelly said.
Water group chairman Budyong Hill said Renwick residents tended to use a lot of water in a short space of time when they came home from work, putting pressure on the pumps.
"Between about 5pm and 8pm there's a real bottleneck in our system."
It was better to water plants late and night or early in the morning, he said.
Kelly said Renwick residents made a "fantastic effort" to conserve water last year to avoid water restrictions, and he hoped they would be able to keep it up.
Three new wells near Conders Bend, on the Wairau River, would be tested by the council this winter, and may spell the end of water restrictions for Renwick.
The wells are expected to have a faster recharge rate than the current wells, which were close to the aquifer's edge, Kelly said.
"It doesn't recharge as quickly as you need."
The water for Blenheim's water supply was also taken from the Wairau aquifer, but was taken closer to the Wairau River where the wells were deeper.
Kelly said water shortages came with the area, and the council understood now they were not the residents' fault.
Renwick Smart and Connected had posted tips on their website for people to save water, such as mulching their gardens, using drippers instead of sprinklers, and planting drought-resistant plants.
It was a good idea to keep a jug of water in the fridge, rather than running taps until the water ran cold, Kelly said.
The sharp decrease in water in the aquifer was due to the river levels dropping in late November, after rainfall earlier in the month.
According to the council website there are 15 other important aquifers in the region, most of which service Marlborough's southern valleys, and seven other minor aquifers.
There was no danger of water shortages elsewhere in the district, with council groundwater scientist Peter Davidson saying most of the aquifers were at a healthy level.
However the situation could change quickly, Davidson said.
The aquifer which supplied Havelock was not experiencing any problems, despite experiencing salinity in the past, Rooney said.
"We've got no issues with the aquifer in Havelock. I think that that's because the flows in the Kaituna River have been better this year," he said
Rooney said the scouts who attended the national jamboree in Renwick last week were able to use water from a bore separate to the town's supply, which provided them with water for bathrooms and toilets.
However the connection was only temporary, and did not provide a high volume of water, Rooney said.
- The Marlborough Express