The Waiwhakaiho flood protection upgrade will be finished on time and within budget despite the original plan being scrapped because of cost, the Taranaki Regional Council says.
A TRC report revealed yesterday the new plan was to raise flood walls along the section of Mangaone Stream between Katere Rd and Devon Rd.
This option replaced the original plan to build three detention dams in the upper catchment to limit downstream flood flows.
The report said only one of the three original proposed dam sites would reduce flood flows, and construction on that site would tack an extra $1.3 million onto the original $1.5m budget. The new plan involved raising 250m of the existing flood wall upstream of Devon Rd, raising a 30m section of wall downstream of Katere Rd and raising the headwalls of the Katere Rd and Devon Rd culverts.
Work on the flood walls would be finished by the end of June.
TRC director operations Stephen Hall said the cost of upgrading the flood walls would be about $200,000 to $300,000 which was covered by the $1.5m budget.
He said the flood walls to be raised were all located behind industrial areas and no private landowners were affected.
"We've been talking to all land owners adjacent and they are all completely happy with the plans," Mr Hall said.
The existing stock banks offered protection from a 1-in-50-years flood, but when the upgrade was complete the protection would be upgraded to a 1-in-100-years flood, he said.
"It's a much greater level of protection than it was."
He was pleased with progress on the project. "It's on time and within budget and achieved the flood protection objective."
The raising of the flood walls will complete the final stage in the three-stage project.
Stage 1, which involved the upgrade to the main Waiwhakaiho stopbank, was completed in June 2011 and stage 2, which involved stopbanking of the Mangaone Stream channel downstream of Devon Rd, is due to be finished by March.
- © Fairfax NZ News
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