A water firm with roadworks across a city centre has urged people to stick to public transport over the Easter weekend.

Southern Water asked motorists to leave their cars at home rather than trying to drive in the centre of Brighton.

North Street, one of the town's main shopping streets, is closed in one direction and traffic is being diverted up West Street while the company replaces the Victorian pipe system.

Thousands of tourists are expected this weekend.

Southern Water is replacing 57km of water pipes across Brighton and Hove, at a cost of £15.5 million.

Diversions are expected to continue for 31 weeks. Southern Water's contractors are working Monday to Saturday from 9am to 5pm.

Bob Lennard, special projects manager for Southern Water, said: "Due to the nature of the works there will be some disruption which unfortunately is unavoidable. However, we are working with Brighton and Hove City Council's highways department and other utilities carrying out works in the area to ensure any disruption is kept to a minimum."

Southern Water is sponsoring Brighton Festival's children's parade on Saturday, May 5. Drivers are encouraged to leave their cars at home on that day, too as the city will be congested for hours.

Alan McCarthy, Brighton and Hove City Council's chief executive, said: "Our city has a first rate public transport system, with excellent rail links to London and a highly efficient bus service. The North Street works are progressing well and are ahead of schedule. However as always we'd encourage people to leave their cars at home and use public transport to visit Brighton and Hove if they possibly can."

Much of the city's water network is between 120 and 150 years old.

The three-year project to replace the old metal pipes with plastic ones began in June 2006 and will finish by the end of December 2009.