Homes in South Shore, Marton and Mereside are without water or suffering with low pressure following two leaks, say United Utilities.
The water company first received calls from customers reporting the issue at around 6.30am on September 14.
One of the leaks is situated on Hemingway and the another is at the junction of Harris Avenue and Ansdell Road.
A third possible leak was discovered another possible burst at the junction of Langdale Road and Ambleside Road.
The company said that engineers were working to resolve the problem but that they were currently unable to say how many properties were affected.
A spokesman added: "Repairs are ongoing to the burst on Hemmingway. A team of engineers have also now started to repair the burst on Harris Avenue at the junction Ansdell Road.
"We have a team of engineers onsite on Langdale Road at the junction on Ambleside Road and repairs will commence as soon as it is safe to do so.
We’re sorry for the trouble this may be causing you and thank you for your patience."
Waterloo Primary Academy on Waterloo Road has informed parents that it will close today due to the water problems.