Installation of the culvert blocks which will connect new drainage from the south to the new pond and floodgate structure. Photo / Supplied
A new milestone has been reached in Waikato Regional Council’s Piako River mouth right stopbank asset rationalisation project.
The project seeks to replace three old floodgates near their end of life with one, while also creating a shorebird habitat and a pond for fish life such as tuna (eels).
The latest milestone is the installation of a culvert, 4m wide x 2.5m high x 18.6m long and weighing 14.7 tonnes, which will connect new drainage from the south to the new pond and floodgate structure, which has yet to be built.
The drains will move excess water from the land through the pond and into the Piako River.
This project was started in 2020 after getting approval of $1.92 million in funding from Kanoa – Regional Economic Development & Investment Unit.
The site was once paddocks that had become inundated by the sea after a king tide burst through a private stopbank. It was being used by shorebirds for foraging and roosting on old farm equipment before being purchased by the council for this project.
The three old floodgates on the true right bank near the mouth of the Piako River and the Firth of Thames are nearing the end of their useful life the regional council says.
The floodgates provide protection to 850ha of good agricultural land and the communities within. This project seeks to rationalise these into one floodgate asset to reduce replacement and ongoing operation and maintenance costs as well as ensure the level of service is maintained along with options for the longevity of flood protection in this area.
This area has significance due to the RAMSAR site at the Firth of Thames, and the link to the RAMSAR site at the Kopuatai Peat Dome. Wetland habitat will be created where stopbanks are set back. This project ties in with the Piako River green corridor project.
So far, the council has:
● repaired the stopbank breach
● removed mangrove seedlings from the new shorebird habitat area
● removed the old farm infrastructure and used sediment from the site to create more naturally raised roosting areas in the habitat area
● excavated drains to move excess water
● excavated the pond to support fish life year-round