Wetland design guidelines lauded

Fish & Game welcomes the new Niwa-DairyNZ resource to help farmers with wetland design and performance.

"New Zealanders are becoming far more aware of the important role wetlands play in taking care of water, from recharging groundwater and augmenting flows, and filtering runoff pollution," New Zealand Fish and Game Council chairman Ray Grubb said.

"Wetlands are vital for wildlife because they provide valuable habitat for both native and valued introduced species. Healthy wetlands are also crucial in helping to minimise the impact of weather events like floods and droughts, which too many New Zealand communities are unfortunately all too familiar with.

"Fish & Game, and game bird hunters, are proud to have played a leading role in wetland protection and conservation — managing and creating numerous wetlands in many parts of the country. That is why Fish & Game has worked with DairyNZ in developing this guidance."

The new guidelines highlight that as wetlands increase from 1% to 5% of a catchment area:

  • Sediment removal typically increases from 50% to 90%.
  • Nitrogen removal increases from 25% to 52% in warmer zones of New Zealand.
  • Nitrogen removal increases from 18% to 38% in cooler zones of New Zealand
  • Phosphorus removal increases from 25% to 48%.