A £2.7m, year-long sewer network upgrade to reduce the risk to 22 properties in the town centre will begin on Monday, July 14.
Contractor Seymour Civil Engineering will install almost 1,200 metres of new pipes.
The work will include construction of an underground chamber in High Chare to install 203 metres of sewer between High Chare and Roman Avenue using trenchless technology.
An underground chamber in the Park View School playing field will be used to install 75 metres of sewer under the A167 to a new chamber in Riverside Park and 120 metres of pipes in the park.
Workers will also install 300 metres of new pipe along Roman Avenue and Park View School playing field and 475 metres in Front Street.
Northumbrian Water project manager Brian Ford said: "Although we appreciate that there will be disruption while the work is underway we hope customers will welcome the benefits and protection the scheme will bring.
"We will do everything we can to minimise any inconvenience and we are working closely with Durham County Council to reduce the impact of the work.
"Work on this scale inevitably requires road closures, traffic lights and diversions and the contractors will inform residents a week before work is due to start in their area.
"This is the latest of the schemes to help protect homes in Chester-le-Street, which started in 2009, helping to protect 120 homes at a total cost of £7.9m.
"Reducing the risk of flooding to customers’ homes and businesses is one of our top priorities."
Officials will explain the scheme to residents on Monday (July 7) at St Mary and St Cuthbert Church, Church Chare, between 5pm and 7pm.
For more information call Northumbrian Water’s customer centre on 0845 717 1100 or visit www.nwl.co.uk