Rio 2016 organisers have scrapped plans for a 4,000-seater stand at the rowing and canoeing venue as part of a $500m (£353m) cost-cutting measure.
Brazil is in a deep recession that is affecting all aspects of the Olympics, which begin on 5 August.
Only about half of the 4.5 million Olympic tickets aimed at the domestic audience have been sold.
The numbers are much worse for the Paralympics, with only 300,000 out of three million domestic tickets sold.
"We are a bit worried with the Paralympics,'' said organising committee spokesman Mario Andrada. "We have to educate, publicise."
He added: "We have cut some services and made some important corrections.
"We have a balanced budget, with some creative solutions. Many of the future Games will be inspired by what we do today."
Organisers are scaling back in a number of areas to balance the operating budget of £1.3bn, with the proposed grandstand at the Rodrigo de Freitas lagoon in central Rio de Janeiro one of the casualties.
The number of unpaid volunteers has also been cut from 70,000 to 50,000.