Northern Ireland could face acute water shortages within the next 30 years, according to a climate change expert.
Experts believe more winter rainfall could lead to flooding
Dr John Sweeney said the Water Service should act now to prepare for drier summers and lower predictability of supply.
He has urged the government to build more reservoirs to offset future water problems.
However, potential water shortages may ironically be accompanied by major flooding because of global warming.
Dr Sweeney, heads a team of climate change researchers at the National University of Ireland, Maynooth, County Kildare.
Considerable investment was required if Northern Ireland was to avoid serious shortfalls in its water supply, he said.
There would be more winter rainfall, leading to rising river levels and flooding.
"The models are saying that the frequency of these events are likely to alter and it is on that basis that it makes judicious sense to start forward planning to cope with both of those extremes," said Dr Sweeney.
Many of the present structures such as reservoirs, bridges and culverts had been "designed with the climate of the last century in mind", said the academic.
"It is time now to put some thought into strategically planning for future structures which will be around in 50 years and take account of future climates."
A conference on climate change is taking place at the ECOS Centre in Ballymena, County Antrim, on Friday.