More than $3.6 million will have to be spent to provide Twizel township with water complying with New Zealand drinking water standards, according to a report from Opus.
The Mackenzie District Council will today decide how to go about upgrading the drinking water available in Twizel, after a final recommendation was made to the council.
The council had proposed in its recent draft annual plan for 2013-14 to spend between $2.1 million and $5.6 million to either upgrade the township's water source, from a bore next to the Fraser Stream, or create a bore 3km to the west, near Ben Ohau Station.
The annual plan, which included a rate rise of more than 8% in Twizel to pay for the work, was adopted earlier this year.
Although the council's preferred option had been a new bore, tests at the proposed site revealed the presence of iron and manganese, both of which would require a treatment plant so they could be removed.
An Opus report, commissioned to assess the viability of conducting further bore tests in the area, says continued exploratory drilling would be too costly.
The report, released yesterday, also said the ''near certainty'' that any source located would need to be treated for iron and manganese would also add to potential costs of taking water from a new source.
The report says an upgrade of the existing 40-year-old water supply is both the most viable and, at an estimated capital cost of $3.6 million (plus gst), the cheapest option available to the council.
''The existing source has considerable advantages in that it is a proven, reliable source which has performed well for the past 40 years,'' the report says.
Council assets manager Bernie Haar said the Twizel supply had been unable to meet drinking water standards for at least the past 10 years, but added that if the council did approve the upgrade, some ''trade-offs'' would be required as the township grew.
''As the town grows to the west, there will have to be in-line booster pumps put in the trunk mains, or the mains supplying the streets to boost the pressure, and the council will have to decide what level of service it wants to provide.''
That would mean a decision would have to be made on what level of firefighting ability it would provide, or whether on-property storage would be required to provide a sufficient firefighting capability, he said.
''Those are policy issues that the council will have to work through later on.''
