Waikato landowners have retired the equivalent of 21 average-sized farms of unproductive land and planted over 3 million trees in the past five years.
The Waikato Regional Council said it had been working closely with the region's landowners to modify their unproductive land in ways that reduced soil erosion, flooding and the amount of sediment getting into waterways, and improved water quality, river stability and river environments.
It also helped to fund the costs of riparian and hill country fencing and planting.
The council's Waikato and West Coast catchments manager Grant Blackie said they financially assisted 1823 landowners in the past five years, with 80 percent of the work funded undertaken in prioritised catchments.
"In the Waipā Zone, for example, we have catchments that are predominantly farmland and highly modified which deliver high loads of the sediment to the Waipa River, so we've had extra funding available for those landowners through MPI's Hill Country Erosion Fund and One Billion Trees," he said.
"Landowners are doing a phenominal job taking care of their land and unfortunately, we always have more landowners wanting to work with us than we have funding available, and there are large areas of the region outside of our priority catchments where only very limited funding is available.
"In the past five years, with our help, landowners have retired 5777 hectares of land - remnant native bush, steep slopes, wetlands and riparian margins - which in total is the equivalent of about 21 average-sized farms in New Zealand."
"All of this work to retire unproductive land helps to contribute to cleaner water, increased biodiversity and improving the climate resilience of each farm."
Catchment and river management work for the past five years has also included 1205km of fencing, to prevent stock access to retired land, and the planting of 3,147,324 plants, mainly native plants but also including smaller numbers of exotic afforestation species and poplar and willow poles.
Blackie said those figures were only through council support and many other landowners were funding this work alone or via other funding sources.
He said the value of the work completed in the region in the past five years was conservatively estimated to be about $27 million, based on the average costs of fencing being $12 per metre and $4 for a tree in the ground.