Pomahaka Water Care Group project co-ordinators marked the establishment of more than 240,000 riparian plants along the tributaries of the Pomahaka River in West Otago on Friday.
Funding officials and local farmers toured the planting sites.
Riparian plants were established across 119 farms with 320 planting sites.
The Pomahaka Water Care Group was initiated in 2014.
From various government funding sources, the group launched the project in 2020, and have since installed more than 110km of riparian fencing and the plants.
The project had doubled its original application of 100,000 plants across the Pomahaka and included the fencing in the funding.
Project manager Lloyd McCall said the Pomahaka River was recognised as "one of the most degraded water systems in Otago".
"The initial plan was to set it up as a corridor planting project, but grew from there to what it is now," he said.
"We managed to achieve our goal and more.
"It’s been all about farmers educating farmers, and this is the result."
"We’re very proud," he said.
Organisers planted a commemorative tree at the Leithen picnic ground, labelling it "nearly the last one" of the three-year project.
Mr McCall said the plantings would change the West Otago landscape.
"The vision is for the Pomahaka River to be recognised as having the absolute highest water quality so that future generations can enjoy the river as we have."
He said the work had been recognised in the Otago Regional Council Sate of the Environment report on water quality.
The executive summary stated the tributaries in the Lower Clutha area showed "many extremely likely or virtually certain improvements across multiple attributes over a 10-year period".
