Native ecosystem trial starts

Horowhenua District Council's Infrastructure Services Group Manager Gallo Saidy, centre, with Hamish Lowe and Sian Cass of Lowe Environmental Impact Ltd, at The Pot in Levin.

A $600,000 government grant has helped Horowhenua District Council launch a five year trial into using native plants to help treat Levin's wastewater.

Ten hectares of pine forest at the Levin wastewater treatment plant's irrigation system, located at the end of Hokio Sand Rd and known locally as 'The Pot', are to be replaced with manuka and kanuka trees.

The native trees had unique properties for filtering pollutants and helping reduce leaching of nitrogen and pathogens, according to HDC.

The trial would also see other native species, including kahikatea, pukatea, rimu, tawa and swamp maire, planted for comparison.

HDC infrastructure services group manager Gallo Saidy said the plant trial and upgrading the irrigation system's technology would significantly reduce leaching, enhance biodiversity, protect soils and improve water quality in the Waiwiri catchment.

The trial would monitor the site and assess environmental impacts.

Mr Saidy said the $1.2 million project became possible after receiving $607,173 from the Ministry for the Environment's Freshwater Improvement Fund.

The 10 hectares of pine forest would be harvested from next month.

Manuka and kanuka planting would start next year and further areas of pines might also be replaced with natives.

HDC said it would be the first council in New Zealand to use a purpose-made native ecosystem at an operational scale for irrigating and treating wastewater.

George Mcdonald, chairman of The Pot landowners' Muaupoko Lands Trust, said the land used to be covered in native plants 30 to 40 years ago and the trial was a good move to return the area to how it used to be.

"We're behind it 100 per cent to try and get the area back to its natural state. We gave our support to council to go ahead with the trial to improve water quality in the catchment," he said.

Environmental advocate and Hokio resident Malcolm Hadlum said the trial was a positive move and manuka had good pollutant absorbing qualities. He said The Pot needed ongoing management.