New water sources have been found for the Otematata and Omarama water schemes, which could result in cheaper costs to upgrade them to meet drinking water standards.
The Waitaki District Council is working across the district upgrading water supplies. Work is now being done on those serving the two Waitaki Valley townships.
That has included looking for new sources of water with a higher quality and the potential to reduce treatment upgrading costs.
In its annual plan, the council estimated it could cost $629,000 to upgrade the Otematata supply and $599,000 for Omarama's.
The Otematata water supply was built in the 1950s to serve a peak population of about 4000 who worked on the Benmore power project. Water is taken from the Otematata River to a 22 million-litre reservoir.
However, the supply fails to meet new standards and has frequent ''boil water'' notices.
Council assets group manager Neil Jorgensen said a new water source next to the river had been found, two bores sunk, resource consent obtained and the reticulation extended to within 100m of them.
Negotiations were under way for land for a new treatment plant.
''The water source offers more stable water quality and is expected to be very good quality most of the time,'' he said.
That quality would be determined during long-term testing before the new supply was commissioned.
The council planned a staged construction.
The first stage would be to deliver untreated water from the new source, which was expected to be clearer and without the slugs, fish and solids of the present supply.
''Boil water'' would remain in place.
The water quality would be monitored, the results determining the extent of treatment.
Ultraviolet treatment was expected to be needed, and test results would determine the unit size.
Filtration could be added if required.
Mr Jorgensen expected water from the new source to be flowing to consumers by Christmas. The old source would be kept as an emergency back-up.
The Omarama water supply's present source is the Omarama Stream, but exploratory drilling next to the existing intake had found a deep supply which was expected to provide consistently high quality water not requiring any treatment.
That upgrade is also staged to avoid over-expenditure.
Production bore holes will be drilled and water from the new source delivered to the reservoir. The existing chlorination would remain.
Water quality would be monitored over time to determine what treatment was required, although quality could be high enough not to warrant it.
If treatment was needed, it would be ultraviolet and filtration.
Water from the new source was expected to be flowing early next year.
