If any local planning authority intends to approve a scheme against the new advice, Welsh ministers will be notified and be able to take over the decision making for themselves.
The advice, hailed by the Welsh government as a UK first, is called the Technical Advice Note 15 (TAN15). It will come into force in December, and dictates that new homes, emergency service developments, schools, and hospitals, must not be located in areas of current or potential high flood risk without strong flood defences.
Commenting on the new guidance, the Welsh government’s climate change minister Julie James said: “Flood risk and coastal erosion in Wales is increasing as a result of climate change. Serious flooding events are becoming more frequent and some areas currently at little risk will become vulnerable to flooding as our climate continues to change.”
She added that the planning system can help communities be “more resilient” to the effects of climate change by locating development in areas away from risk of flooding.
In the case of developments in areas of low flood risk, and areas protected by strong flood defences, developers will still need to pass the acceptability tests in TAN15 to secure approval.
These tests include providing justification for the location in a flood risk area, for it being on brownfield land, and being resilient in the event of a flood.
Speaking to the BBC, James also said that funding was available for development on other land, such as former industrial sites, which she said should be chosen instead of areas at risk of flooding.
Developers will need to consult the Natural Resources Wales Flood Map for Planning, which identifies four types of flood zone, each with its own TAN15 advice attached.
The zones are based on current risk levels with additional allowances made for climate change, and the map will be updated every year in May and November.
From 1 December, all planning applications in the system awaiting a decision, and all new planning applications, will be assessed against the new advice and map.
This also extends to any Local Development Plans under review and those yet to reach the formal examination stage after this date.
You can find further details on the new advice here.