Work will soon on the final phase of a £445,000 scheme to replace 800 metres of burst-prone water mains in Burgess Hill.
Phase three of the replacement scheme in London Road and Cromwell Road begins on September 30, and lasts for eight weeks, according to a spokesman for South East Water.
The final phase involves laying 175 metres of pipe in Cromwell Road.
Jeremy Dufour, project manager at South East Water, said: “The first two phases have been successfully completed on time.
"We worked closely with West Sussex Highways to work out how to do cause as little disruption as possible but for safety reasons Cromwell Road must be closed from its junctions with Fairfield Road and London Road for the final phase.
“Other traffic management measures, including temporary traffic lights, may need to be used at times, particularly when we install the pipe across London Road.
“We will ensure that we maintain access to homes and businesses. Customers have been sent letters containing information about the work and we appreciate the patience and cooperation of local residents, businesses and motorists.”
Diversion routes will be signposted for the duration of the works.