There is not enough funding available to deliver any of the major infrastructure projects included in the Living With Water Plan (LWWP) for Belfast, NI Water has said.
It says the severity of wastewater and drainage development constraints will increase as a result.
The company plans to set out the implications of deferring the £1.9bn programme in March.
The decision means work to upgrade sewage works at Sydenham, Whitehouse and Kinnegar cannot proceed, and works planned at Glenmachan, Greenisland, Carrickfergus and on the sea outfalls will not start.
NI Water says it will begin a programme of maintenance this spring to “ensure the existing facility operates as effectively as possible”.
Last year, Infrastructure Minister John O’Dowd said an estimated 50% increase in the cost of the plan was not affordable.
When LWWP was published it set out three objectives: to protect against flooding, enhance the environment and provide the capacity to allow further development such as house building.
The lack of wastewater infrastructure has been a longstanding concern of developers who said it was preventing economic growth in the city.