Eight communities at risk of flooding are to benefit from £12.5m of European and local funding for defence work.
The cash will double spending on flood defences for three years
Up to 2,000 homes and businesses should be protected under the "Umbrella Project, paid for by match funding from the Objective One development scheme.
The Conwy Valley is one area to benefit, where Trefriw and Llanrwst have been hit by floods three times in two years.
The £5m over three years is matched by the Welsh Assembly Government.
The remainder will come from local authorities, developers and flood defence committees.
Abererch in Gwynedd and Resolven, St Clears and Pontardawe in south west Wales are among the other areas in line for the work.
The Conwy Valley was hit by major flooding in February 2004, with further events in September 2004 and January 2005.
Chris Nichols' hotel and restaurant business in Trefriw was one of those hit.
He said: "Part of developing the business was to try to develop the garden, but two years running the whole project has really been hammered back.
FLOOD DEFENCE AREAS
"This year I suspect we'll be lucky to get back to where we were two years ago and if we have another flood we'll be put back again.
"I'm hopeful that flood defences will be put in place. The situation is obviously critical. We seem to be in an acceleratinlgy downward spiral."
He said the concern locally was that the Environment Agency was aiming to shore up the river's banks rather than dredging what he described as a "bottleneck".
The Environment Agency's flood defence manager for Wales, John Mosedale, said: "This money is only available to us for three years so we're on an express track to get that money spent.
"If (communities) have been flooded frequently then, yes, they are certainly going to see a difference.
"It is a huge amount of money in flood defence terms. Our normal budget is about £4.5m, so over three years it will double that expenditure.
"The thing with flood defences is to reduce the number of times that (communities) get flooded to a level which is "acceptable," something like a 100-1 chance."
He said an exhibition of flood defence options for Trefriw would be on display in the town from 18-20 July.
Environment Minister Carwyn Jones said: "Eight projects across Wales will benefit from the money and we expect that all we get a share".