Council water and waste services asset and commercial manager Tom Osborn said council contractors were having a closer look, via CCTV, at damage to Kaikorai Valley's clay sewerage pipes, which were up to 115 years old.
It had been apparent for years there were issues with pipes in the valley, when sewage overflowed during storms. Blockages were only more likely with time.
The footage showed which pipes needed to be replaced and had so far indicated about $7 million of work needed to be done, making it a major pipe replacement project.
The council was spending about $5 million replacing pipes in Andersons Bay at present, with the work expected to be completed by July next year.
Mr Osborn said the Kaikorai Valley work would be done in three stages over three years, starting in 2015-16.
Pipeline renewals were accounted for in the council's long-term budgets, and the cost was ''well within'' budget.
The new pipes should last 90 to 100 years.
The numbers
DCC's water production/service system. -
• 1405km of pipeline (40% of the wastewater pipes are earthenware and over 100 years old).
• 35 pumping stations.
• 57 reservoirs (raw and treated).
• 14 treatment plants.
