River science Waiatara region

Waitara students had the opportunity to investigate water quality at Mangahinau stream. Emily Roberts (Taranaki Regional Council) and Denise Goodman (Department of Conservation) led the group to compare and contrast stream health data from a site that has riparian planting to a site without planting. A clear difference in water quality should be evident from students’ investigations.

Researcher, Nick Spencer of Landcare Research reported that ‘maintaining vegetated margins along waterways is beneficial. Grass and sedges (grasslike plants) help filter water running off the land and planting shrubs and trees will stabilize the stream bank and cool the water by providing shade. Lower water temperatures can benefit aquatic insect and fish communities’.

Riparian planting has been devised as part of the solution to the challenges facing our waterways. The Sustainable Dairying: Water Accord launched in July 2013, for example, has become a national riparian plan demonstrating the dairy industry’s commitment to improving water quality in New Zealand.

Of particular importance is the vegetation along the riparian margin of waterways, which provide a vital role in this cleanup. Sediment from erosion, unused added nutrients, toxins, and much more can be filtered, sequestered or transformed by habitats around waterways to create cleaner, wildlife-supporting habitats for us all.

Despite the apparent value of riparian buffers, many regions, farms, industries do not have consistent plans of action aimed at restoring our rivers, streams, wetlands. A major advantage of the sustainable diarying accord is to ‘provide the tools that allow the cumulative impact of riparian activities to be evaluated at scales that will provide enduring and substantial benefits from improved quality of waterways and associated riparian areas’.

Since implementing the Accord, it is reported that ‘initial analyses of a five-metre riparian buffer along all waterways in the 17 million hectares of ‘productive’ land in New Zealand indicated major benefits’.