The stench of sewage at Belmore Basin has been so bad, the windows of the Harbourfront Restaurant have stayed closed.
Restaurant owner Angelo Scioscia said the staff had been closing the windows and running the airconditioners to ensure customers weren't confronted by the smell of sewage while dining.
Mr Scioscia said the sewage issues started on the weekend before last and had had a definite effect on business, which was usually brisk in January.
"It has led to a bit of a decline and it's been unpleasant for our diners to say the least," Mr Scioscia said.
"People are still coming through the doors but it was a lot quieter around the weekend. With the kids not being able to swim in the water, there just wasn't as many people around."
Mr Scioscia was at the restaurant yesterday morning and described the smell as like a septic tank but said by yesterday afternoon the smell had disappeared.
He said that was likely due to the work of Sydney Water, which had thoroughly flushed out all the pipes and greasetraps.
He understood that Sydney Water knew where the sewage had come from and was expecting the situation to be resolved soon.
Swany Einarsson from the Harbourside Fish Market said the sewage leak had also affected that business due to Sydney Water workers looking for the pipe under the car park.
"There was a lot less parking because they were digging it up looking for the pipe," Ms Einarsson said.
As well as customers not being able to find a place to park, she added that the smell had been a factor in the past week.
"In here you can't smell it much but we can see it in the faces as they walk past," she said.
"It's not very nice."