The campaign would run over the summer months and planting would begin in winter.
Horizons Farming Ltd managing director Stuart Ellingham said the company was committed to incorporating sustainable practices.
"We know it's possible because we already have these practices in place on our farms. We have promised to match any funds raised by the crowdfunding campaign dollar-for-dollar and, will spend that money on native restoration and enhancement plantings on our properties."
He said water health was an important legacy he hoped to leave to his grandchildren.
QEII National Trust spokeswoman Genevieve Bennett said they were also excited about the campaign and working alongside landowners who were committed to water quality.
"So far, the national trust has partnered on four Million Metres stream projects and raised approximately $800,000 towards waterways restoration work on covenanted properties. We would love Kiwis to get behind the Mangapapa project and help protect this precious resource."
- For more information or to support the campaign, visit millionmetres.org.nz