The turning of the flow of Longbenton Letch marks the completion of the second phase of a £6 million scheme to reduce flood risk in Killingworth and Longbenton.
Northumbrian Water, North Tyneside Council and the Environment Agency have been working on the joint surface water management scheme since July 2016.
The first phase involved constructing a new surface water pipe that would allow the partners to divert Longbenton Letch out of the sewer network, and directly into the nearby Forest Hall Letch.
This would help to increase the amount of space in the sewer network, which is key to reducing the risk of flooding.
The second phase, which began in April last year, saw the construction of three natural surface water storage areas on Killingworth Moor, to make sure that the additional flows into Forest Hall Letch would be held back during times of heavy rainfall.
The watercourse couldn′t be diverted until the second phase of work was completed, but now that it has been, the risk of flooding in the area has already been reduced.
Once phase three of the scheme is complete, more than 3,500 properties in the area will benefit from reduced flood risk.
This final part of the work, which is expected to begin in summer 2018 and take around 6 months to complete, will be carried out by Northumbrian Water′s partners, ESH-MWH. It will involve re-contouring around the south bank of Killingworth Lake and some new planting.
The agencies are planning an event next month, where customers will be able to have their say on the scheme and find out about the proposals. More details about the event will be provided closer to the time.
Lynn Preston, Northumbrian Water′s Project Manager for the scheme, said: "This project is a fantastic example of how much can be achieved by working together to reduce the risk of flooding in an innovative and sustainable way.
"We′re delighted that we′ve already helped to make a difference to the community and will help to provide even further risk reduction in the area once phase three gets underway."
Cllr John Harrison, cabinet member for Housing and Transport, North Tyneside Council, said: "I am delighted that the second phase of this project is now officially complete.
"This is great news for local residents and gives them real confidence that their homes will be protected during heavy rainfall.
"As a council, we are committed to reducing the risk of flooding and this is a great example of different organisations working well together to achieve this."
Nicola Hyslop, Project Manager with the Environment Agency, said: "Turning the flow of the river is a significant milestone in what is an innovative project which will reduce flood risk to the community and enhance the environment.
"By collaborating in this way with our partners we can combine our resources to ensure we are providing the best possible solution to flooding in the most cost effective way, resulting in better protection for the community."
Residents can keep up to date on the progress of the works by following the link to the Killingworth & Longbenton page on www.nwlcommunityportal.co.uk.