Upgrade work is set to take place between Maryland and Forest Gate to increase reliability into and out of Liverpool Street station.
More effective drainage will be installed and worn-out track replaced to increase reliability on Greater Anglia and Transport for London (TfL) services.
Network Rail’s team will be digging down below the level of the tracks to install 360 metres of pipes.
This new infrastructure is designed to carry rainwater away from the tracks quickly and effectively.
Network Rail will also replace the old track and the sleepers that support the rails.
Network Rail commented on the importance of the work set to take place.
Ellie Burrows, Network Rail’s Route Director for Anglia said: “We are always working to drive down delays for our passengers and freight partners.
“In this case we are improving drainage in an area which has historically been prone to flood-related delays, reducing the possibility of problems in future.
“The upgraded drainage will also help to extend the life of the new track we are installing as part of the work.
“All in all, we are boosting reliability along one of the busiest stretches of line on Anglia.”
Jamie Burles, Managing Director at Greater Anglia spoke on the work taking place between Maryland and Forest Gate.
Mr Burles said: “Network Rail’s track renewals and drainage improvements on this critical part of the railway will help to keep our trains running on time.
“We’ll be operating a rail replacement bus service while the work takes place, so customers will be able to complete their journeys.
“Customers should check before they travel and allow more time for their journeys.
“We’d like to thank passengers for their patience and understanding.”