Coastal defence work along the seafront in Colwyn Bay is due to begin in the new year.
Conwy council planners backed the plan as part of a multi-million pound Colwyn Bay Waterfront project.
The new coastal defences will include raising the promenade and using reinforced concrete retaining walls.
Storm damage regularly closes the coast road and the council warned properties, the main north Wales railway line and the A55 expressway, could be at risk.
The work will be carried out opposite the northern entrance to the town's Eirias Park.
As well as increasing coastal protection in Colwyn Bay, the work will also increase the promenade area.
"We believe this coastal defence work is essential for Colwyn Bay's future," said Councillor Mike Priestley, cabinet member for the environment with Conwy council.
He added that the area is badly affected when the sea pounds the current defences.
"It affects the infrastructure nearby and the local community because the coast road is regularly closed due to storm damage," he said.
A council spokesperson said engineering work, which is due to begin in the new year, will be followed by an improvement scheme along the promenade.