Council planned to spend $8.45 million building the popular Riverbend Park, but the final amount spent was $10.4 million.

About $5.4 million was to be spent on resurfacing UTAS Stadium and developing a 22,000 square metre turf farm at Dilston, however the final cost was $6.2 million.

The budgets for the projects blew out by a combined total of $2.8 million

City of Launceston mayor Albert van Zetten said the extra spending had delivered the community "world class assets" it would benefit from for years to come.

"Riverbend Park is going to be a fantastic tourist attraction for our city and it's something we did want to get right," he said.

"It was 2015 when we did the estimates for it and by the time the work was done from 2018 onwards, the costs have obviously went higher and in addition to that there's been an extra basketball court and other work that's been done which has been added to the project."

Councillor van Zetten said the UTAS Stadium overspend was needed to "get the job done".

"What they found when they did the work was that some of the base wasn't quite suitable so they had to do more work," he said.

"We had to get it right and that's why we had to spend a bit more than originally budgeted."

The stadium and park made Launceston a better place to live, Cr van Zetten said.

"We are a good city but we want to be a great regional city and we need a Riverbend Park, we need a UTAS Stadium, we need to have world class sporting events here so we do need to have these facilities and we need to keep them to a fantastic standard otherwise we won't get the AFL games and we won't get Big Bashg and we won't even get the World Cup soccer here," he said.

Cr Van Zetten said there were lessons that could be learned from the budgeting process the stadium and park projects went through.

"When we budgeted and did the costing for Riverbend Park we should have added 20 per cent in the beginning but we didn't know how long it was going to take us to do the job and we didn't know what extra projects were required as well," he said.

"I think it's always probably prudent for council in future to have a contingency in there of around 20 per cent and then you would find we'd come within budget. It's something we will no doubt continue to look at in the future."

Council's chief financial officer Paul Gimpl said both projects exceeded their budgets by less than the 20 per cent contingency amount "generally accepted" for projects which were big and complex.