Bypass working to ensure township has water supply

The bypass runs over a formed race and the end section to the spillway is piped, as shown in this image. PHOTOS/MAP: CLUTHA DISTRICT COUNCIL

The Clutha District Council has completed work on a bypass around its historic Phoenix Dam, to ensure the township of Lawrence will continue to be supplied with water, and has lifted the stage-three water restrictions for the town due to the approaching winter.

But it has asked residents to continue to be mindful of water use and report any leaks.

Phoenix Dam is a historic water supply dam located 3km northeast of and above Lawrence.

The council said, in a release this week, the work was completed earlier this month and, aside from a minor washout following some rain in the first week, it had been providing the township with clear water since then.

Work has been done to ensure the supply of the Lawrence water supply.

The estimated cost for the bypass is $30,000-$50,000, but to date, clearance of the outer race by hand and purchase of some pipe work to rebuild the siphon has cost about $65,000.

A council spokesperson said costs for the project would be capitalised and funded by rates over time.

Council deputy chief executive Jules Witt said it was reassuring to have the bypass "operational and working effectively".

The bypass work had been a "top priority for the council" following the dam owner Port Blakely’s intention and subsequent formal notification to decommission its dam due to ongoing safety concerns related to its age.

A map showing where Bungtown Creek starts, northeast of the Phoenix Dam, and where the siphon starts and the point where the Bungtown outer race and Bluejacket Creek above the dam meet, before flowing into the dam.

Resource consent has been sought to undertake the bypass work and Port Blakely had given consent to do this work on its land.

Mr Witt said the council was acutely aware the water source at Blue Jacket Creek — the Phoenix catchment — would be insufficient to ensure continued supply to Lawrence.

Alongside the bypass work, further work was being done be able to pipe water from another source at Bungtown Creek.

The bypass is a temporary solution until the new Greenfield Bore — with water supplied from near the Clutha River — is operational, which will supply the Lawrence township in the future.

That project, which is under construction, involves a new water-treatment plant and the amalgamation of pipe networks with four pumping stations and a network of 48.5km of pipe work.

But water issues are not over for Lawrence residents.

There is still a boil-water notice in place for the township, which Mr Witt said relates to chlorine levels at the treatment plant, and is a separate issue.