Carterton's Mangatarere Restoration Society, a volunteer group dedicated to improving the water quality of the Mangatarere Stream, has begun a year-long intensive planting project.
The society recently planted more than 1000 natives along the stream near Brooklyn Road bridge.
They plan to plant thousands more up to February next year.
Project co-ordinator Esther Dijkstra said the stream was significant because it was the main tributary into the Waiohine River and had been identified as an important spawning ground for brown trout, as well as four native fish species.
"In 2009, water quality tests showed that the stream was suffering from the effects of storm water and waste water discharge, nutrient leaching and stock accessing the stream," she said.
