Scottish Water finished a major upgrade of parts of the network of water mains running underneath the city's busiest streets.
The rehabilitation work, which involved the replacement of five miles of ageing distribution mains, will boost services to thousands of properties.
Geoff Aitkenhead, Scottish Water's Asset Management Director, said: "Scottish Water is delighted to have completed this major investment in our water infrastructure in parts of the centre of Glasgow.
"This is great news for Glasgow and underlines Scottish Water's commitment to supporting the regeneration of the city.
"These improvements will benefit customers for many years to come. They will also help the city as it prepares for the Glasgow 2014 Commonwealth Games and other major events."
Many of the pipes that supply water to thousands of properties and customers in the city centre date back to the Victorian age.The stretches upgraded were improved because of a history of bursts on them.
The £3.5m upgrade, which started in July 2012 and has been completed on schedule.
However, the news came at the end of a difficult period which saw mains bursts cause major disruption the East End and Bearsden, inEast Dunbartonshire.
Last week, drivers faced delays when a burst mains pipe on Westmuir Street shut down Shettleston Road at Old Shettleston Road.
And last month, around 23,000 homes were left without water and several houses were flooded after a burst water main in Bearsden.
The 3ft-wide pipe under Maryhill Road, near Canniesburn Toll, sent flood water careering into homes in nearby Cluny Drive.
A Scottish Water spokesman said: "It is impossible to avoid bursts completely but improvement work like this continues to substantially reduce the risk."
The completion of the city centre project was welcomed by Stuart Patrick, chief executive of Glasgow Chamber of Commerce.
He said: "We appreciate the efforts of Scottish Water in keeping disruption to a minimum during these works, and in being receptive to the needs of the business community.
"An example of this was the decision to cease operations temporarily over the Christmas period, in understanding of its importance to the retail and leisure sectors."
The investment is also helping to provide clearer, fresher drinking water to properties in the area.
In addition, it will reduce the amount of water produced at the Milngavie and Balmore water treatment works, in turn reducing operating costs and carbon emissions.
Meanwhile, Scottish Water is looking hear the views of residents in the city.
Customers are invited to the company's Consultative Meeting (ACM) at the Crowne Plaza Hotel on Congress Road on August 27 at 5.30pm for an open question and answer session that will form part of the meeting.
Ronnie Mercer, chairman of Scottish Water, said: "We look forward to meeting our customers."