Environment Waikato is working with the New Zealand Forest and Bird Society and other agencies on a plan to enhance a wetland area on the Kauaeranga River floodplain near Thames.
The floodplain, which lies at the southern gateway to the town, is a flat area beside the Kauaeranga River, which collects tidal and flood water and helps prevent it flowing into nearby residential areas.
“It’s grazed by cattle and horses and looks like a regular grassy paddock, but because it’s regularly inundated it’s actually home to a variety of rare species specially adapted for living in wet conditions,” Environment Waikato land management officer Emily O’Donnell said.
The flood plain is home to rare and threatened plants such as the marsh club rush, sea meadow and marsh ribbon wood. It also provides habitat for threatened bird species including the white heron, fern bird and banded rail. The area is also important for managing flood storage and high water flows as part of the local flood protection scheme.
“With some riparian protection this site has significant potential as a spawning area for whitebait and there is scope to increase its recreation value by providing walking, bike and horse tracks as part of the enhancement project,” Ms O’Donnell said.
The Thames Branch of the New Zealand Forest and Bird Society (NZFBS) approached Environment Waikato with a plan to enhance parts of the floodplain about a year ago.
The regional council owns and manages the land under the Waihou Valley flood control scheme and leases it to Thames-Coromandel District Council. A number of recreational groups make use of the area at the moment. The planned enhancement will seek to maintain and possibly enhance the area for these groups.
“Forest and Bird would like to recreate the kind of wetland you would have found beside the river a couple of hundred years ago, before people changed the landscape,” Ms O’Donnell said.
“The goal is to provide a few shallow ponds and plant native species like flaxes, cabbage trees and kahikatea as well as creating spawning habitat for whitebait.”
Thames-Coromandel District Council, Thames-Coromandel Community Board, the Department of Conservation and Ngati Maru are also partners in the project.
Environment Waikato is now working with these groups to maximise the environmental and community benefits of the project. A key consideration is ensuring the essential flood management function of the floodplain is maintained.
“We are currently reviewing the Waihou Valley flood protection scheme to assess whether it has the capacity to manage the effects of climate change and possible sea level rise so the timing is good to also consider enhancement works like this,” Ms O’Donnell said.
As well as looking at providing financial support for the project, Environment Waikato is providing technical support through its engineers and environmental enhancement team.
Environment Waikato River and Catchment Services Committee chair Andra Neeley said the majority of the once extensive alluvial wetland areas within the Thames district had been lost to land drainage, protection and development.
If the wetland enhancement work could be carried out without any decrease in the land’s ability to accommodate flood flows, the project would provide a great chance to enhance biodiversity on land Environment Waikato already owned, while providing more recreational opportunities for the Thames community in partnership with local groups, she said.