SA Water is preparing to replace more than 700 metres of water main in Port Lincoln over the next few months.
New pipes will be installed along Liverpool Street between Bligh Street and Porter Street, and on Porter Street between Railway Place and Liverpool Street.
This upgrade is expected to take up to three months to complete.
SA Water acting chief executive Mark Gobbie said crews would work mostly between 7pm and 6am to minimise impact to local businesses, residents and commuters.
He said new PVC pipes would be installed with an approximate 100-year lifespan which ensured SA Water could keep providing customers with world class water services.
"We will also ensure residents and businesses are notified of any temporary water supply interruptions that are necessary when we move their connections over from the old to new pipes," he said.
"This is one of many water main replacements SA Water is undertaking in 2019, and we look forward to continuing our investment in communities right across the state."
The work is a part of SA Water's $137 million investment to replace about 375,000 metres of water mains across South Australia between 2016 and 2020.