The City of Charlottetown is on the hunt for millions of litres of water it believes is leaking out of its water system before it gets to homes and businesses.

Some of the water pipes in the city are more than a century old. At this time of year they can fail spectacularly, sending water gushing to the surface.

"Now things are starting to shift with the frost coming out, so we're going to busy for the next few weeks probably with leaks popping up here there and everywhere," said utility supervisor Blaine Parkman.

But officials believe Charlottetown's aging water system has many leaks than go undetected. The province has ordered the city to conduct an audit, to find and fix leaks, before the city taps into new groundwater sources outside the city.

City officials say it could take five to seven years to complete the search for leaks and do repairs, and at this point there is no way of estimating what the cost might be.

The search for leaks is complicated by the fact that most homes in the city do not have water meters, so the city cannot directly compare how much water is being used by homes in an area with how much is being drawn by the system.

"It definitely makes a difference because we're estimating their water use versus measuring their water use," said Ramona Doyle, projects officer with the utility.

"When we measure it makes it easier to measure how much we're losing to leaks."

The city intends to hire a consultant to design and conduct the audit. It will likely involve the use of electronic acoustic equipment to listen for leaks in underground pipes.

The city is also asking residents to help find leaks in their own homes, and will be sending out information on how to do that with water bills this spring.