World Wetlands Day: Flood mitigation
Today (February 2) is World Wetlands day and comes just six days after Auckland’s flood emergency began.
Dr Matthew Bradbury is a spokesman for the Tuia Pito Ora New Zealand Institute of Landscape Architect’s Climate Action Group. He says while the floods are proving devastating, costly and far-reaching, they have also had the strange effect of revealing Tamaki Makaurau's original landscape.
Kopupaka Reserve at Westgate by Isthmus has wetlands which were created and planted with reeds and other suitable plant species.
“Prior to the 20th-century urbanisation of the city, the indigenous landscape was a complex system of streams, rivers, wetlands and bays. This landscape was built out in the 20th century. Streams were piped, marshes and bays were filled in.”
He says a good example of the is Opoutukeha, the stream and wetland that is now Grey Lynn Park and the Cox's Bay Reserve.
Grey Lynn’s Dryden Street in Auckland which flooded quickly last Friday.
“The Opoutukeha returned with a vengeance on Friday the 27th as Grey Lynn Park flooded and Dryden Street became a raging torrent barrelling towards the Waitamata.”
He believes restoring wetlands is one way flooding can be absorbed and slowed down.
“There are several notable examples of restored wetlands, the Waiatarua wetland in Remuera, the largest wetland restoration project in Tamaki which was rebuilt in 1987. Several newly constructed wetlands are throughout the isthmus now; Vaughan Stream Corridor Wetlands in Long Bay, which now provide 28 hectares of parkland and which were designed by Landlab, and the Kopupaka Reserve in Westgate by the Isthmus group.”
Landlab’s Vaughan Stream project on Auckland’s North Shore.
Dr Bradbury says these restored streams and wetlands can not only help with absorbing and retaining flooding but can help restore Auckland's biodiversity.
Local bodies around the country are also speaking out about the importance of wetlands.
The Waikato River Authority is urging landowners and conservation groups to consider wetland restoration for waterway health and climate change mitigation.
Authority Chief Executive, Bob Penter, says the rainstorm events of the past few days are another reminder of the value of wetlands.
“While the damage in Auckland from recent rainfall highlights the important role wetlands can play in urban areas to capture and slow the release of rainfall, we also need many more wetlands in rural Waikato catchments to treat contaminants and provide important ecosystem habitat,” he says.
Northlanders are also being urged to celebrate their region’s unique and diverse wetlands.
National Wetland Trust poster.
Amy Macdonald, who chairs the Northland Regional Council’s Natural Resources Working Party, says World Wetlands Day is celebrated every year to raise global awareness about the value of wetlands for humanity and the planet.
She says in the past, many people didn't recognise the true value of wetlands and as a result nearly all of them had been converted to pasture or urban use.
"Wetlands are important because they help prevent flooding and improve water quality, as well as providing the necessary habitat for a number of unique species of plants and animals, many of which are rare."