The North Canterbury dairy farmer and consultant has been a committee member for seven years, but said leading the committee during the Zone Implementation Programme Addendum (ZIPA) process was an all-consuming, and rewarding, task.
''I learned so much about science, working with different types of people and the process of reaching a decision through consensus.
''To be honest, it's been really tough and is one of the hardest things I have ever done.''
When Mr Ashby joined the committee seven years ago, he approached the role with some degree of trepidation.
''I wear a number of different hats as a farmer, a business owner and I am also a keen environmentalist.
''The situation we're in now with our waterways has happened over many decades and I knew that even though it would take up nearly all of my time, it was something I had to do.''
He recalled being presented with a stack of bulging folders to read over the summer before starting with the zone committee and feeling a bit overwhelmed at the first few meetings.
''There's so much to learn from a scientific point of view so in the beginning I just tried to absorb as much of it as I could and then moved forward from there.''
Mr Ashby was proud of what the zone committee had achieved through its recommendations, which formed the basis for part of the proposed Plan Change 7 to the Canterbury Land and Water Regional Plan. Submissions on this plan change have just closed.
''It's a real credit to the committee that although we're from different backgrounds and have a wide range of views we've come up with recommendations that will improve our waterways.
''We devoted so many hours and put the rest of our lives on hold to do something that we hope will benefit the wider community,'' he said.
''To be honest, it's going to be really hard on farmers and I hope that the broader public will support us as we work together to clean up our streams and rivers.''
The ZIPA process became something of a marathon when Environment Canterbury opted to delay the process in 2017 while it conducted scientific investigations into potential groundwater movements under the Waimakariri River.
The investigations later revealed low levels of ''nitrate-nitrogen'' in aquifers and wells in Kaiapoi, Belfast and northern Christchurch, from groundwater which originated on the north side of the Waimakariri River.
While the levels remained low, the findings led to a ZIPA which set some tough standards for farmers to meet.
The ZIPA set a framework for reducing nitrate levels, requiring dairy farmers in priority areas to make a further 15% reduction in nitrate levels beyond ''good management practice'' by 2030.
Mr Ashby will remain on the committee as a community member, while Kaiapoi retailer Michael Blackwell took over as chairman and Oxford dairy farmer Cameron Henderson, who is also Federated Farmers North Canterbury president, was the new deputy chairman.
It was an exciting time for the committee as it worked on catchment management plans and took visible action to improve Waimakariri's waterways.
''We're looking forward to working together with the wider community on local projects to enhance biodiversity, streams and rivers.
''The most important thing is that we all recognise the problem and take joint action to fix it,'' he said.
-By David Hill
