The retired Maf policy manager was a key support for farmers on the lower Waitaki plains as an irrigation scheme was initiated in the 1970s.
His longtime involvement in irrigation was rewarded recently with the Ron Cocks Memorial Award for outstanding leadership in irrigation.
He received the award jointly with Ashburton-based farm business consultant and rural valuer Bob Engelbrecht at IrrigationNZ's conference in Napier.
Together, the pair had more than a century of involvement in advocating for agriculture and irrigation interests, IrrigationNZ chairman John Donkers said.
Mr McFadden began his career as a farm adviser with Maf in the mid-1960s and was based in Oamaru from 1974 to 1980.
From the early 1980s, he worked with farmers going through deregulation and drought and later moved into MAF Policy, as he realised it offered opportunities ''to make a real difference to people''.
In 1988, he was handed responsibility for running the country's 38 irrigation schemes and preparing them for sale to farmers when the Ministry of Works was closed.
He later managed many research contracts looking at the sustainability and economics of irrigation. He was also involved in the early days of the Canterbury Water Management Strategy as an instigator of funding and steering group member.
Now living in Christchurch, he recalled the construction of the Lower Waitaki scheme.
The percentage of farmers seeking to be involved with it well exceeded the required level, which was no surprise, given the concerns about drought. Severe droughts in the late 1960s had devastated the area, he said.
It tended to be an older age group of farmers and, after obtaining water, many sold out to younger ones.
It was a ''real win-win''. The older farmers realised good sales for their properties, allowing them to move elsewhere or retire, and a ''great invigoration of young, new blood'' came in, he said.
Mr McFadden said the changes in land use that followed were never anticipated.
Planning and preparation for the scheme was all based on continued intensification of sheep and beef and cropping operations, and the change happened very quickly.
Getting water on to the free-draining, stony soils was a ''huge breakthrough'' and a very capable group of farmers was involved, led by Sid Hurst, coincidentally the inaugural recipient of the Ron Cocks Memorial Award in 2008.
During and up to that time, there had been a push to get water on to the North Otago downlands. Not much progress was made then and it was ''amazing'' to see what happened after the opening of the North Otago Irrigation Company's scheme in 2006.
Receiving the Ron Cocks award came ''out of the blue'' and he was thrilled to receive it alongside Mr Engelbrecht.
The pair had worked closely together on ''all sorts of things'' and shared very similar philosophies and experiences. It was the first time the award had been given to two individuals.