A revised proposal of floodway improvement works expected to significantly reduce flood risks for the majority of property owners around Graham’s Creek in Tairua will be revisited by Waikato Regional Council in 2014/15 after the Manaia Road causeway is upgraded.
At a recent community meeting attended by more than 50 people, the majority of affected property owners did not support the proposed floodway improvement works. Instead, they strongly believe that increasing the capacity of the bridge to discharge water into the harbour under the causeway on Manaia Road will address the flooding problems.
Many of those who supported the floodway improvement works also believe the causeway upgrade should be carried out first.
A technical review carried out by Waikato Regional Council last year and technical reports commissioned by Thames-Coromandel District Council (TCDC) do not support the property owners’ views. This work shows that while upgrading the bridge on its own would significantly reduce flood levels at the causeway, it would provide only minor benefits upstream, meaning the majority of property owners would still experience flooding.
As a result, the regional council reconfirmed the commitment it made in the 2012-2022 Long Term Plan to fund the $600,000 of proposed works in 2014/15. Key works proposed include:
- channel improvement works to improve the flow of water
- construction of a spillway to redirect floodwater from the main channel to the downstream reserve
- new stopbanks and earth banks to retain floodwater in the channel
- increasing the height of the existing Manaia Road stopbank so floodwater up to a 1-in-100 year flood event doesn’t go over it.
Councillors also agreed to discuss with TCDC the potential to proceed with the causeway upgrade without the floodway improvement works.
Through its 10 year plan process TCDC set aside $1.2 million to upgrade the Manaia Road causeway, but the funding was subject to floodway improvement works being carried out in conjunction with the upgrade.