Natural Resources Wales (NRW) has awarded the construction contract for the first phase of the St Asaph flood scheme to North Wales based company, Dawnus.
The project, set to begin in October, involves removing Spring Gardens Bridge and replacing it with a higher and wider bridge.
This will increase flow capacity downstream of the city, which will reduce flood water levels in St Asaph.
The second phase of the scheme will see flood defenses improved and enhanced in the city and at other locations, benefiting properties and the wider area. This is scheduled to start in January 2017.
A drop-in session will be held in St Asaph on Wednesday 5 October (2pm-7pm) so that local people can find out more about when and how the work will be undertaken.
The drop-in session follows consultation with residents who have properties that will be directly affected by the new defenses, which took place over the last few months.
Once completed, in 2017, the scheme will also bring recreational benefits to the city by improving foot and cycle paths. and it will bring a boost to biodiversity by planting trees and blue bells, and putting up bird and bat boxes.