"I had a contract to serve the needs of the community. When the fundamental safety and wellbeing of that community is at risk it's only what could be expected of me. It's just something that you accept when going into public service."
Mr Cook retired last year. He spent 52 years in public service, the last 45 of them for the Manawatu-Whanganui Regional Council. For the final 15 years he commuted from his home in Marton to Palmerston North for his role as river manager.
The 2004 flood was his biggest test.
"It was pretty hard seeing the devastation and impact on people's lives and livelihoods," he said.
Millions of dollars were spent to improve flood protection afterward. The work went on for more than 10 years.
"I didn't see it finished."
He's convinced the benefits of that work will increase and be felt for a long time. There have been some rewards - he's met appreciative people and had a sense of achievement from seeing work completed.
Mr Cook's expertise has been called on in other emergency situations, including the erection of temporary flood barriers after the Christchurch earthquakes.
Now retired, he's in a new phase of life but still occasionally called on "especially around emergency events and other specific issues where institutional knowledge has some value".
A long-term Marton resident, Mr Cook has also been elected to its local council, first to Marton Borough Council from 1980-89 and then to Rangitikei District Council from 1989 to 1992.