Regional council integrated catchment management group manager Iain Maxwell said the project would provide job opportunities for fencing contractors, particularly those who had taken on new staff after Covid-19.
"Fencing our waterways on a large scale is an important part of the process to prevent excessive nutrient levels and restore water quality," he said.
"We had a number of landowners who were in a position to commence works immediately, but were also prepared to go above and beyond the minimum requirements for stock exclusion from waterways."
Maxwell expected the project would encourage farmers to carry out riparian plantings, which would help to filter sediments and nutrients before they enter waterways, prevent land erosion and increase the habitat for native wildlife.
At least 195km of fencing around waterways is expected to be completed by July 2022, with the bulk due to be done within six months.
The Crown funding, administered by Ministry for the Environment, is part of the Government's $1.3 billion Jobs for Nature programme.
In July, the Government announced $162m from the programme would go to 23 regional council projects, which are being supported by about $30m of ratepayer funding.
Maxwell said the further investment would complement the existing work that councils already deliver, including sedimentation issues, pest and weed control, riparian planting, erosion mitigation, conservation, biosecurity, and large-scale planting.