The Rivers Agency has updated its online flood maps to include predictions of areas which may be affected in years to come.
It suggests that more than 46,000 homes across Northern Ireland are at risk.
Computer modelling on the impact of climate change has been used to predict the areas liable to flooding.
Agriculture Minister Michelle O'Neill said the maps should help householders prepare for flooding events and assist those planning on building a house.
"The updated on-line information will also allow people living or working in areas at flood risk from rivers, sea and heavy rainfall to take necessary precautions now and in the future," said the minister.
The climate change element provides an illustration of the predictive river flood plains and coastal inundations for the year 2030.
While the extension of river flood plains may cause concern to some householders, the new data is also intended to help planners.
The Environment Minister Alex Attwood said: "This will enhance the planning system and is a good example of joined-up government."
The Rivers Agency points out that although, the map provides a general overview of the areas at risk of flooding, it is not intended to provide a definitive assessment of flood risk to individual properties.