$3m approved to replace filter systems for Macaskill Lakes
Regional councillors have stumped up more than $3 million to install a new filter system in Wellington's only water storage lakes after a new kind of algae were found.
An investigation into the Macaskill Lakes began early last year when the Greater Wellington Regional Council received complaints about the water's taste and odour.
Concern was especially expressed about algae living on the floor of both lakes which could produce toxins, affecting water quality.
A Wellington Water spokeswoman said the Macaskill Lakes were filled by the Hutt River, and acted as a back-up for when the river was too low to meet demand, or too dirty after heavy rainfall.
"We have to leave certain flow levels in the rivers and in the aquifer as part of our consents, so if the demand for water exceeds the amount of water that we are allowed to take, then the shortfall has to be made up from the Macaskill Lakes," she said.
The lakes had a combined useable capacity of approximately 3,350 million litres, or enough to meet average water use for about 23 days.
Figures show that in the last year the lakes were drawn on for water on 150 separate days.
Wellington Water group manager, network strategy and planning, Mark Kinvig said additional routine monitoring of the lakes' water would cost $80,000 a year, with an extra $200,000 in monitoring funding required if toxins were detected.
Some councillors requested greater transparency on the costings at their meeting on Wednesday, and Kinvig said the sum, totalling $3.32m, included installation of the new filters as well as removal of the existing system.
Kinvig said it would take roughly two to three months to complete the installation of the new filter system.
Council chairman Chris Laidlaw said the decision was the kind of precautionary step which experience had shown to be worth it.