Freak bore failure affects water supply: Immediate ban on sprinklers introduced - 23/01/2009Wanganui District Council Chief Executive Kevin Ross today announced that the city's water supply has been hit by the failure of No. 3 Bore at Kai Iwi.
There have been no previous indications of problems with this bore and it was not scheduled for any capital renewal work.
"The failure has come as a complete surprise to our engineers and infrastructure staff," Mr Ross said.
The underground bore pump tripped out on overload and is currently being evaluated. It is thought it is unlikely to be primarily due to a pump fault but this will not be confirmed until next week.
As part of the process of assessing the bore failure, a large crane is being brought in to lift the pump from the bore on Monday. This is a major undertaking and is expected to take most of the day.
On Tuesday specialist camera equipment from Wellington will be used to check for any problems with the screen and casing (100 metres deep) which may be letting sand through.
No. 3 Bore provides one-third of the water supply from Kai Iwi. The city uses 30M to 36M litres of water per day. With the No. 3 Bore out, other bores can supply a total of 27M litres per day. The storage capacity is 60M litres, giving a buffer of 10-15 days.
If the bore problem is found to be an electrical fault with the pump, the Council has a spare pump which could see the bore back in action by Monday, February 2. However, if the problem is a screen failure it could take three to eight months to repair.
The Council is continuing work to get new bores at Westmere on line but these will not be available as part of the city supply until July and the process cannot be fast-tracked. A new bore would take 14-16 months to install.
Mr Ross today activated a ban on domestic sprinkler use under the Water Bylaw 2008. Hand-held hosing is permitted.
Non-domestic users can continue to use sprinklers under their approved water programme. A controlled watering programme has been put in place for Wanganui's parks and the water feature at Kowhai Park has been turned off.
The Fire Service has been advised and requested not to test hydrants.
Some consumers, particular in the central city and Springvale, may notice a reduction in water pressure. Areas affected by lower pressure may also experience dirty water.
Wanganui residents are asked to report all leaks to the Council so they can be repaired.