Each ratepayer across the region would have paid $5 a year.
People talked about it being just the cost of a cup of coffee, he said, without realising after that period other regional projects would be funded.
"I didn't see Horizons supporting a Manawatū car racing track. I would far rather be putting money into cleaning up rivers."
He is an advocate of rates restraint, and of the council sticking to core business.
Cotton said he was surprised to be voted chairman of the council's catchment operations committee this term and would like to continue in that role.
He's spent a lot of time chairing scheme meetings, and taking feedback to the council.
One result has been the $320,000 clearing of the Matarawa Stream in Whanganui East being paid for by everyone in Whanganui - not just its immediate neighbours.
He's also spent a lot of time telling councils and other groups exactly what Horizons does.
Cotton is proud of pushing the council to monitor and measure its work - for example, by finding out how many of the 25,000 poplar poles it plants each year survive.
He's also helped in the formation of the Whangaehu/Mangawhero Rivers Catchment Group, and wants something similar for the Kai Iwi, Ototoka and Mowhanau streams.
"I want to spend a lot of time on those rivers in this next term."