Water conservation vital as rains fail
Dam unable to supplement town’s supply at current rate of use
Dannevirke residents are being asked to conserve water as much as possible as the dry weather continues and the town's raw water reservoir (impounded supply) recovers from leakage.
Tararua District Council group manager — infrastructure Chris Chapman said it was not currently a full-blown emergency as in the 2019-2020 drought.
“But at the moment we're certainly using more water as a town than we can currently take from the river under our resource consent.”
The Tamaki River was down to less than 240 litres per second, which restricted how much the council could take under consents with Horizons Regional Council.
This improved slightly but is expected to reduce to low flows again in the near future.
Chapman said that normally the raw water reservoir was used to supplement water from the river during low flows.
However, the storage dam was not at full capacity due to a leak that was discovered in July last year and it does not have enough water to supplement the river take throughout summer unless water use reduced.
One theory is that the 2019-2020 drought had caused the ground to dry out and contract, which led to the plastic liner being damaged.
Repairs were completed by early December and the reservoir was being refilled, but the council was still restricted by consents on how much it could take.
“Because of the leak and our inability to fill [the reservoir] completely before the river entered low flows, we can't get through all of summer so we do need to reduce the demand to a point that's sustainable,” Chapman said.
“We're trying to take a proactive approach into addressing demand before we get into emergency situations, and have established a temporary team to progress improvements to water supply, demand and communications.”
Rain forecast as part of the recent cyclone did not eventuate.
Chapman said any rain would help, but even if the river levels were high, there were still constraints on how much water council can take for the town's supply.
“It's not like open season where we fill everything up as quick as we can,” he said.
The other problem was that it was a small catchment in the Tamaki River, so while it might pour down in town, it could be minimal there.
“It takes a lot of consistent rainfall before we can increase our water take over an extended period of time, especially when water table levels are low.”
Mayor Tracey Collis understood residents' concerns.
She said the impounded supply was there because the town had always gone to restrictions and the aim when it was put in was to mitigate that.
“There's a lot of factors there. An increasing population and water usage. Recent drought and infrastructure failure causing leaks from the impounded supply.
“We've also got historic extraordinary water users on our supply, which need to be addressed to ensure that everybody is reducing water use generally but also when the town faces water restrictions.
“This is just the way the town's grown out and how those systems were put in place in the early days.”
Dannevirke is currently under a level four water restriction which is a total ban on outdoor use — that meant no sprinklers and no hoses could be used.
Under current water restrictions, there would be a process to apply for extraordinary water use in which council would consider exemptions.
Application forms are be available at the service centres and on council's website.
Council officers will be following up with those who did not adhere to the water restriction level.
Council was offering tips on how to conserve water and was working with extraordinary users to see what could be done to help.
Some tips included: recycling grey water, especially in gardens; not doing laundry unless it's a full load; shortening time in the shower; cooking food in as little water as possible.
“If everyone plays their part, we should get through summer without any emergencies,” Chapman said.