Up to 37,000 properties in pre-planning are at risk of not being built due to a “lack of investment in water and sewerage infrastructure”.
According to figures released by NI Water around 19,000 units, including private and social homes, in pre-planning may not be able to proceed due to wastewater capacity constraints.
It said these developments are “impacted by existing NI Water assets that are high polluting” and would require a “full capital upgrade before further new connections can be made to the wastewater system”.
A further 18,000 properties in pre-planning are only able to progress if developers are able to self-fund connection works.
It is also understood that a further 1,865 units have been recommended for refusal between June 2021 and May 2024.
In a letter to a property developer and seen by The Irish News, NI Water said the current budget allocation has resulted in “limited ability to increase capacity to accommodate new connections”.
Mid Ulster MLA Patsy McGlone said if the executive was serious about building affordable homes it needs to look at ways to fund infrastructure to support them.
“The lack of investment in water and sewerage infrastructure has brought us to a critical point.
“Houses cannot be built, inevitably driving the cost of existing housing stock up, public services cannot be expanded leaving many places at paralysis point.”
This follows reports of a “alarming drop” in housing starts across the north. During the first half of 2024 only 1,500 new homes were started, with poor water infrastructure cited as the main driver for the drop.
The SDLP MLA added: “If the Executive is serious about affordable housing and improved services to the community, they need to seriously look at ways to fund the water and sewerage systems.
“It cannot all be left to developers to bear the costs as, in many cases, that simply doesn’t stack financially up.”
A spokesperson for NI Water added that its most recent business plan had “identified the need to invest £2.7bn to begin addressing historic underinvestment”, with £1bn earmarked for Belfast alone.
NI Water said it “will continue to work with developers, the environmental regulator and Department for Infrastructure to ensure we maximise the potential of the investment that has been made available”.
A spokesperson for DfI said it had been “historically underfunded by over a decade of cuts by the British Government”.
“And in 2023-24 we managed to invest over half a billion pounds of public money in water and sewerage infrastructure. NI Water is continuing to carry out significant improvements across the North,” the added.
“There is much to be achieved with the resources available, and that will require all stakeholders to work constructively and responsibly to achieve the maximum benefits possible to keep pace with our economic, societal and climate responsibilities.”
In March a report by the Audit Office warned that development applications were at risk due to poor water infrastructure and the department said it “considering the reports findings in full”.