Boaters are asked to drive slowly in Safety Bay this week.
Moncrief Construction is replacing an underway sanitary main.
The city say the contract will have divers on site doing the repairs.
In the meantime, the sidewalk on the west side of 1st Avenue South will be closed Tuesday and Wednesday to accommodate work being carried out at the Rotary Peace Park.
Pedestrians are asked to use the sidewalk on the east side of the street.