Living Water looking at the catchment area for Hikurangi Swamp

Part of the Okarika Pocket in the Hikurangi Swamp.

Living Water — a 10-year partnership between Fonterra and the Department of Conservation — is conducting a catchment condition survey in the Okarika Pocket of the Hikurangi Swamp.

The survey, linked with World Wetlands Day earlier this month, aims to reduce sediment in the Wairua River, which flows into the northern end of the Kaipara Harbour.

"The survey is identifying and mapping wetland areas on all properties including dairy farms that can be protected and enhanced as well as identifying and mapping areas where new patches of wetland can be created," says Living Water Wairua River site leader Ben Herbert.

The catchment condition survey will increase the area of wetland habitat for native species such as the fernbird/matata (pictured) and the Australasian bittern/matuku.

"The survey will map the location of creeks, drains and other wetland areas on all farms and lifestyle properties, identify barriers preventing native fish moving along the waterways as part of their life cycle, and record the length of waterway that's already fenced.

"This is valuable information farmers and landowners can use to help native fish on their migration journeys and to ensure waterways on their properties are protected."

Living Water sustainable dairying manager Matt Highway says the baseline data will also help identify priority areas to achieve the greatest reduction in sediment flow into the Wairua River.

Along with reducing sediment load, the work will increase the area of wetland habitat for native species including Australasian Bittern/matuku, the fernbird /matata and black mudfish.

Living Water is working alongside dairy farmers, iwi, conservation groups, schools, local government and other agencies to demonstrate sustainable dairying in healthy freshwater ecosystems in five key dairying regions.