Auckland-Waikato Fish & Game will be assisting throughout the transformation and will also be caretakers of the completed wetland.
"We have designed a 4ha wetland that will have several zones that can all cope with varying degrees of flooding," Mr Simcock says.
"The largest part of the wetland is open water to encourage ducks and other wetland bird species to make it their permanent home.
This main body of water will be approximately 3.7ha and the remaining 0.3ha will consist of differing zones of planting that can be on both dry land during the summer and have wet feet during the winter."
A barrier will keep the wetland above the normal level Lake Kimihia, a large lake under the care of the Department of Conservation. This is to keep pest fish species out of the wetland and assist water quality.
A gate will be installed to allow for the removal of any pest fish species that may enter the wetland during large floods.
"Work on the wetland began recently with a stream diversion first. Ecologists carried out intensive fishing of the old stream that needed to be diverted and native fish species were caught and transferred. Pest species that were caught, including 98 carp, were destroyed," says Ecologist Keith Hamill.
Nearly 300 tuna (freshwater eels) have been transferred to a safer area. Most were the short-fin species but endangered long-fin eels were also found.
The wetland construction continues during February and March with an expected completion in April. When the Huntly section is completed the wetland will be around 500m from the highway.
The work is part of an ecological plan developed by the Transport Agency in collaboration with Fish and Game.