From above it looks like any other river.
But up close, the Marokopa River through Ruawai Farm in Te Anga is exceptionally clear.
Data collected by Waikato Regional Council shows the water quality is some of the best in the region.
The river rates particularly highly for macroinvertebrates - tiny creatures without backbones such as insects and worms. The more of those, the healthier the water.
David Carey - with his wife Claire and their two adult sons Michael and Craig - own and manage Ruawai Farms. One is a drystock unit which David has farmed and lived on for more than 30 years. The second, adjacent, property is a dairy farm which Michael manages.
Water monitoring began in 2002 with the Waikato Regional Council monitoring 50 sites across the region which are used to report ecosystem health, giving a final Macroinvertebrate Community Index score of MCI.
"A score of 134 is the highest and that's generally taken in the bush where rivers comes out of the bush," David said. "When we started in there, we were probably 112 or 114 which was still a good rating. In the last two years we were 130.
"Last year we were 132. So that's not on clarity, that is on the aquatic life within it, and the aquatic life in here is probably perfect. You can't get it better."
The MCI score of 132 is considered "excellent" and usually occurs in water with less pressure from nutrients, intensive land use, lower temperatures and erosion.
But the Careys say their approach to farming helps too. They're organic, have an extensive planting programme and have fenced roughly 30km of wetland and riverbank to keep stock out.
"Up until 15 years ago, we had sheep and cattle and they grazed right up to the river. Since then we have had poplars and native trees come up," David said.
They also have an advantage because upstream is bush and forestry, so the water is already very healthy before it gets to them.
Craig Carey said the move to organics was prompted about 11 years ago when there was growing public concern about sustainable farming practices.
"We saw issues around water quality and, instead of sitting back complaining or letting things happen, it was easier to start early and do a bit each year," he said.
"We are actively trying to farm in a more environmentally sustainable, all-round ethical manner, in line with the growing concerns raised by the general public.
"Organics is ideal in this regard as it is a return to a far less intensive and more sustainable style of farming with any 'old' harmful practices removed as well."
The Careys blame poor farm management and understanding in yesteryear for the current water quality crisis.
"This generation of farmers that own dairy farms are paying a massive cost towards cleaning it up from what's happened in the past," David said. "Rightly or wrongly, that's the rules and it's the determination of the farmers that is going to do it.
"On our two farms here, we have spent $420,000 to date on fencing, bridges, planting and effluent systems, and everything like that so it's not a small amount.
"We were one of the first farms in the Waikato to install a solids separator and built an effluent capture pond of immense size to ensure we never have an issue with overflow or flooding into waterways," Craig added.
The family has planted around 10,000 trees and plants on their property with plans for another 1000 per year.
"I pick a lot of them up," Claire said. "It's all very casually done."
The Carey family is part of a growing movement of farmers around the country working to restore and protect the environment. They recommend going further than regulations suggest.
"Even your drains along your farm - they don't require fencing but it's a good thing to do, to fence off drains and plant trees along," Craig said. "It all helps keep the main river quality so much better."
Ruawai Farm is around 900 hectares with 850 cattle, meaning a much lower stocking rate than many other farms - less than one animal per hectare. But being organic presents its own problems.
"The biggest issue of organic farming is you can't use herbicides, and our two biggest problems are gorse and blackberry," Craig said. "So we have to make a decision, in some areas if it's too steep to get machinery onto. We either have to revert back to gorse or at some stage plant trees on it to kill out the gorse."
Putting the environment and the animals first is an ethos which is at the centre of their farming practice and it's paying off, not only with better water quality, but also to their bottom line.
"It's important that your customers know you're producing a product ethically and that you're doing a good job looking after it," Craig said. "And personally, we just feel it's important to leave the land in a better situation than what it was."
Waikato Regional Council has specific advice for farmers:
• Putting a fencing setback ensures stock are kept out of waterways, thus reducing nutrients entering the system.
• Planting promotes increased stability of stream banks and lowers water temperatures which supports native fauna
• Plants filter nutrients out of runoff