Nathan Davey, Craig Botting, Mark Proctor and Jason Watt, coached by Terry Michie, beat 20 other teams in the United Fire Brigades Association (UFBA) contest in Cromwell on Friday and Saturday.
The prizegiving was on Saturday night and the team and supporters arrived back in Balclutha yesterday with a home-town celebration on the agenda.
''There was some celebrating after the presentation but ... I think they'll let their hair down now they're back home - it's a big achievement,'' Mr Michie said.
It was the first time a Balclutha team had won a national title and 39 years since a South Island team had won the event, he said. Gore won in 1974.
The waterway challenge is a hose-running competition designed to test firefighters' core skills. The team had a nervous wait to see where it finished.
Nine rounds of competition were held over two days and Balclutha got off to an excellent start on Friday, winning the first round.
It was four points clear of its nearest rival at the start of Saturday's competition, finished the event at 11am and then had to wait to see how the other top teams went.
''You didn't know the result until all those other teams, who were up with us, finished ... Nerve-racking doesn't come close to describing it - I've never been so emotional in my life,'' Mr Michie, who is also the brigade's deputy chief fire officer, said.
Balclutha beat Silverdale by two points and ''thoroughly deserved to win,'' he said.
''Silverdale was tipped to win, so it was great for a small country brigade like Balclutha to win the title and we had most of the Otago-Southland teams cheering us on, backing us.''
The win meant Balclutha and Silverdale will represent New Zealand in the Australian waterway championships in Tasmania this year.
''We're definitely going to go to that. The UFBA pays for the team to go, but we'll be doing some fundraising so some of the supporters can go too,'' Mr Michie said.
The team had been together for five years and had won the Otago-Southland provincial waterway competition for two successive years.
''These four guys are pretty dedicated to the event and they've been building towards it for the last two or three years.''
They started training for the nationals in October, getting together twice a week. Competing in the national was the aim, so winning was a real bonus, he said.
A two-person team event also formed part of the waterway challenge. That was won by a Darfield team.
