Upgraded water over a year away

Alexandra residents can circle Christmas 2022 on their calendars as the expected date to turn their taps on to an improved quality of water supply.

This comes almost five years after the Central Otago District Council first agreed to construction and treatment options and a pipeline route in 2017.

The council announced in a release on Friday it had awarded a contract for supply and installation of the membrane plant for the Lake Dunstan water supply treatment to Pall Marshall Water Consortium for $3.7million.

Due to international supply and shipping issues, the membranes were expected to take nine months to arrive from the manufacturer Pall in Germany, five months to install and six weeks to commission.

Based on this timeline, the go-live date for the Lake Dunstan water supply project was expected to be December 2022.

Negotiations were under way with other key suppliers and contractors to enable construction to start on the remaining project components.

Central Otago Mayor Tim Cadogan said there was "no doubt" Alexandra residents had been waiting a long time for higher-quality water.

"Many are disappointed that the pipes to supply that water from the Clyde bore head have been in the ground for so long with no water flowing through them.”

The project was consulted on in the 2018 long-term plan and installation of the pipeline to carry the water from the bore site at Clyde to the treatment plant in Alexandra at the Northern Reservoir began in May 2019 and was completed in July 2020. Construction of the new treatment plant was originally scheduled to be completed by mid-2020, but was delayed by both the discovery of Lindavia algae in Lake Dunstan and need for further consideration for the project’s filtration system, as well as Covid-19 setbacks.

The revised date of autumn 2022 completion has now been further extended due to international supply and shipping issues related to the continued impact of Covid-19.

Mr Cadogan said the discovery of Lindavia in the lake, and the need to undertake trials to ensure filtration met drinking water standards added more than a year to the project.

"Lindavia would not only have blocked the filtration system proposed before the trials but would also have blocked people’s home irrigation systems, so this was a good problem to find out about early,” Mr Cadogan said.

“This discovery, combined with delays caused by Covid lockdowns and related supply issues, means the project is well behind schedule but council remains committed to completing the project."