Homes and businesses are at increased risk from flash floods as a result of Stormont budget cuts, it has been warned.
Underground gullies which help thwart sudden flooding are now not being kept clear because vehicles and equipment have been taken out of service.
Transport NI vans and machinery used to fix potholes and sweep the roads, among other functions, have been mothballed indefinitely.
Roads Minister Danny Kennedy confirmed the Transport NI vehicles have been taken out of service until the funding situation improves.
He has been accused of being "irresponsible" and risking flooding situations which could be "catastrophic".
DUP MLA Paul Frew claimed: "This is all designed to hold the Executive to ransom and is irresponsible of the minister. He got more money from street lights and now he is hoping to do the same here. I know his department has faced budget cuts but it is up to him to manage his finances in a way which lessens the impact on the public, not increase it."
But the minister's Ulster Unionist Party colleague Robin Swann hit back, saying: "Danny Kennedy has repeatedly given warnings about the effects an inadequate budget allocation would have on his department's ability to provide their services.
"If Mr Frew wants to play a constructive role in resolving these issues he should have a word in the ear of his own party colleague, the Finance Minister Simon Hamilton, given he is the one in charge of the purse strings."
In a written Assembly answer to Mr Frew yesterday, Mr Kennedy said: "Funding will not be available to permit the normal levels of pothole repair and mechanical gully cleaning, for example, to be carried out.
"This will result in some vehicles being taken out of service until the funding situation improves."
Mr Frew said: "There's no doubt that most of our major flooding problems are the result of surface rainwater caused by massive downpours and this is where the gullies become vitally important. It could lead to situations which are catastrophic."
Mr Kennedy's department said he had made it clear that Transport NI will "proactively continue to monitor known areas prone to flooding".