A major artery in Dunedin's water network is in need of a $700,000 overhaul, after rapidly deteriorating in less than half its expected lifespan.
Contractors for the Dunedin City Council are expected to begin a six-week project to replace a 755m section of trunk water main, running between the Dunedin Botanic Garden and Woodhaugh Garden, on Monday.
The 250mm water main - linking reservoirs at Maori Hill and Signal Hill - ran under land on the edge of the two gardens, as well as the north ground, council engineering project manager Marco Vega said.
However, the replacement section would be reinstalled under Opoho Rd, Bank and North Sts in staged work before and after Christmas, Mr Vega said.
High water pressure in the area was a feature of the water network, but had contributed to the water main's deterioration and more bursts in recent times, he said.
The pipe had an expected lifespan of 80 to 100 years, but was being replaced after just 45 years, he said.
Installing a new water main underneath the road would also provide better protection against tree root intrusion, and, together with modern construction techniques, should see it survive for its expected lifespan, he believed.
"This one in particular seems to have been very badly affected by the high pressures.
"We're expecting the new one not to have that kind of problem."
The council had written to about 40 business and homeowners in the area, warning them that work beginning on Monday would involve traffic and water supply disruptions, he said.
The work programme had been designed to reduce disruption to businesses in the area during the busy holiday period, he said.
Stage one would see 255m of water main replaced along Opoho Rd, between Arden and Knox Sts, between Monday and December 16.
Work would then continue on a 200m section of George St, between Dolphin St and Willowbank, from December 16-22.
Work on both sections would continue between 7am and 7pm, Monday to Saturday, and at times the roads would be reduced to one lane.
Work closest to the retail sector, on Opoho Rd and Bank St, from Knox St to Dolphin Rd, would run from about January 9-30.
Work on the first two sections would begin closest to the retail area and move away, to further reduce disruption, he said.
The work could also lead to water supply disruptions of up to four hours during the project's final stages, but properties would be notified in advance, he said.
