Spillway planned to spare homes in Otiria¯ and Moerewa A
proposed $5 million spillway could reduce the floods that regularly wreak havoc in O¯ tiria and Moerewa.
The most recent deluge, in July last year, swamped homes with contaminated floodwater, forced families to evacuate and left travellers stranded. It came on the back of similar floods in 2014 and 2011, with smaller events between.
Now the Northland Regional Council, using a combination of ratepayer and central government funding, is proposing to build a spillway to divert floodwaters from the Waiharakeke and O¯ tiria streams away from homes.
While the exact route has yet to be decided, the idea is to skim water off the flood plain upstream of Pokapu Rd, then return it to the Waiharakeke Stream at a point further downstream where its channel can handle the volume.
At present floodwater continues to flow along the flood plain, swamping O¯ tiria and Moerewa on its way to the sea.
Regional council deputy chairman Justin Blaikie said the Government had agreed to stump up $2.89m, more than half the cost of the project, through the Provincial Development Unit. The rest of the cost would be split, with $1.5m from a Northlandwide flood infrastructure rate and $630,000 from a new targeted Tauma¯rere rivers management rate.
Normally residents would have to pay 30 per cent of the cost of flood protection, but in this case, thanks to Government funding, the locals’ share was about 13 per cent.
Blaikie said the council was gauging community support for the spillway, and the costs, via the Long-Term Plan consultation process. If the proposal proceeded in its current form it would add about $1.45 a year to the Northland-wide flood infrastructure rate, and an extra $57.50 (including GST) a year for 12 years for ratepayers in the targeted rate area.
Blaikie said local knowledge had been key to the project, with residents Mike Butler, Wiremu Keretene and Murray Armstrong working with council staff and engineers to come up with potential spillway routes to reduce future flooding.
Meanwhile, the regional council is
proposing a separate project to reduce flooding along Old Whangae Rd, in Kawakawa. That would involve building a 450m-long stopbank to deflect floodwater away from businesses. If approved, work would start in 2024 and cost about $1.5m.
That would mean a extra $1 a year
on the Northland-wide flood infrastructure rate and $29.40 annually on the local targeted rate, starting in 2024.
If both projects proceed, the targeted rate in the Tauma¯rere rivers catchment area would start at $57.50 and rise to $86.90 in 2024.