7 September 2018
Well water level low - emergency pumping likely
The Gore District Council is expecting to start pumping water from the Mataura River in the next few days to minimise the effect of low water levels in its main well on Gore residents this summer.
The water level in Cooper’s Wells is the lowest it has been for this time of year in recent memory. It is at a similar level to where it was in March this year when the Council had Level 4 water restrictions in place.
3 Waters Asset Manager Matt Bayliss said the well’s low level was due to the low river flow over recent months. It was not as a result of high water use by residents.
“A lack of high river flows over winter means the aquifer that feeds the well has never fully recovered from the exceptionally dry summer.
“We know from past experience that a decent flood in the river recharges the aquifer and lifts our water level in the well quite quickly.”
Mr Bayliss said the Council was better placed this year to supplement the well’s water levels with emergency pumping from the Mataura River after installing a more permanent pipeline and electric pumping system.
“We now have more control over how rapidly we lift the aquifer level.”
Last summer the Council needed to pump up to 33 litres per second from the river into the aquifer to maintain a continuous supply.
“However, due to the lower demand at the moment, we will start emergency pumping at a rate of between 10 litres and 15 litres per second. It’s hoped the smaller quantity of river water will be sufficiently diluted by what’s in the aquifer so it doesn’t affect the taste.”
The water is treated with chlorine at the Council’s water treatment plant before entering the town’s supply network.
Notification of emergency pumping starting will be posted on the Council’s Facebook page and website.
Last year the Council provided a water tanker for people to access fresh water. However, only about 1000 litres were used in three to four weeks.
“If the public want a tanker again we can provide one. However, based on previous demand there doesn’t appear to be much need.”
The Council also has a drilling contractor starting next week to investigate potential alternative ground water supplies in Gore and Mataura.
Emergency pumping is planned only for Gore at this point. Mataura’s water supply is showing no signs of not keeping up with demand at this stage.
- The water being supplied to Mataura Valley Milk from the well at the Gore A&P showgrounds has no impact on the water level in Cooper’s Wells.
- Water take consents for dairy farms are consented and monitored by Environment Southland.
- The main means of recharging the aquifer that feeds water to Cooper’s Wells is high flow levels (flooding) in the Mataura River.
- The emergency pumping process involves feeding river water into a disused well at the Cooper’s Wells site. It goes into the aquifer, which provides natural filtration, before it is extracted from the active No.1 well.