A further £6m is being invested to strengthen Victorian sea defences on the promenade in Old Colwyn.
Work worth £1.6m had already begun on a 2m-high (6.5ft) rock wall at Splash Point, Conwy, in January.
But there were fears locally that the funding was insufficient to protect it from rough seas and high tides which had led to frequent closures.
Conwy County Borough Council said the announcement by the Welsh Government was "great news".
The new investment comes as part of a £16m Resilient Roads Fund which was announced by Ken Skates, minister for economy, transport and North Wales, on Friday
On Facebook, the council said the money "will be used to improve coastal defences and upgrade the active travel route for pedestrians and cyclists".
For many years the Old Colwyn section of the Colwyn Bay promenade and cycle track has been battered by storms and bad weather leading to frequent closures.
There have also been fears over the adjacent railway line, owned by Network Rail, and the Old Colwyn Sewerage system, owned by Dwr Cymru.
Mr Skates said the fund will "help local authorities pay for much-needed work".
It is believed the promenade in Old Colwyn will remain closed while work continues.