Cromwell's community board has approved $660,000 of improvements to the town's water supplies and associated infrastructure.
It will result in drinking water free of manganese, separate irrigation for Anderson Park and Cromwell College, and the upgrade of a Lowburn pump station.
Central Otago District Council utility services manager Peter Greenwood sought and received funding for three projects at the board's meeting in Cromwell yesterday.
Mr Greenwood said an original estimate of $100,000 to drill a new bore for the town's drinking water had doubled.
It would now cost $200,000 for a bore to replace an existing one which had high levels of manganese.
Last August, the board resolved to spend $100,000 on a new bore, instead of altering its existing filtration plant.
Mr Greenwood said since then a test bore had been drilled which identified an appropriate site, although it was 300m from the existing treatment plant.
"We've got to have some rather large 300mm pipes leading to the plant, and the bore is rather large as well, so all up it's a large project.
"That's the main reason for it being double the cost."
Mr Greenwood said water from the new bore - which could be available in April - had a lower hardness level and no manganese.
The old bore could be used for irrigation.
The board could again consider altering the filtration plant instead of approving the new bore, but that was a risky option, Mr Greenwood said.
"We've got concerns that the estimate done may well be out for that option as well.
"However, when you put down a bore things can change over time . . . it's never an exact science.
"I would like to guarantee that it was a silver bullet but there are some risks," he said.
Board chairman Neil Gillespie said either option had potential risks for water quality, and the board was already committed to establishing a replacement bore.
Mr Greenwood also sought $315,000 to upgrade the Lowburn hall pump station to a level which would allow the Lowburn bridge pump station to be decommissioned.
Last year, the board allocated $126,000 to upgrade the Lowburn bridge pump station.
It was in poor condition due to inadequate sealing of an electrical duct which had allowed hydrogen sulphide to attack its metallic components.
Mr Greenwood said consultants investigating the upgrade discovered it would be better and cheaper in the long run to instead upgrade the Lowburn hall pump station.
It would mean the degraded Lowburn bridge pump station could be decommissioned and new pipes laid to re-direct water flow into the upgraded Lowburn hall station.
While expensive in the short term, it would reduce ongoing maintenance costs, remove all costs associated with the Lowburn bridge station, and improve efficiency of the overall system, he said.
After land-owner approval had been secured, design, tendering, and an estimated 12-week construction period, he anticipated the new system would be working by September.
The sum of $145,000 was also allocated to install infrastructure which would allow bore water to irrigate Anderson Park and Cromwell College grounds, which are now being irrigated by the town's potable water supply.
Mr Greenwood said a test bore drilled near the park was found to be suitable.
The money would cover its connection to a power supply, controls and a pump, new piping to connect it to existing irrigation systems, disconnection of those systems from the town supply, and upgrades to a single irrigation control system.
Removing Anderson Park and Cromwell College irrigation from the town's drinking water supply would reduce demand on the system equivalent to about 250 households, increasing the supply's longevity by about five years, he said.
The new irrigation system should be working by September.
