NI Water has detailed the scale of the investment challenge facing water and wastewater services in the Lisburn & Castlereagh area, during a briefing to Lisburn & Castlereagh City Council.

The utility set out pressures across an ageing network and the funding constraints that are limiting the pace of much‑needed upgrades.

Councillors heard that essential works are progressing across the district, even as financial pressures persist. Priority wastewater schemes under way include:

- Mill Road Storm Overflow (£6.36m) – completion due Summer 2027

- Knockbracken Storm Overflow (£6.4m) – completing 2026/27

- Kinnegar Drainage Area Dundonald Phase 2 – improvements to multiple network sites

- Waringfield WwPS upgrade (£2.2m) – completed 2025

- Dromara WwTW – £800k essential base maintenance

- Lisburn West WwTW – £9.6m maintenance and electrical upgrades

Updates were also provided on drinking water investments designed to bolster supply, resilience and quality, namely:

- Manse Road, Carryduff Watermain (£1.2m) – supporting 350 new homes and improving water pressures

- Aghalislone Water Pumping Station to Boomers Service Reservoir Trunk Watermain Replacement (£1m) – replacing the existing pumping main with a problematic burst history.

- Granular Activated Carbon Media Replacement at Castor Bay WTW to remove taste and odour compounds that often accompany algal blooms. Dr Steve Blockwell, Head of Investment Management at NI Water, outlined the company's local operational footprint, the condition of its assets and the increasing strain on the wastewater network. Dr Blockwell said: "Across Northern Ireland, the wastewater system is under severe pressure. Years of under investment mean many assets are now operating beyond their intended capacity, and this Council is no exception."

Speaking to the wider funding picture, he added: "Without long‑term, sustainable capital investment, we can only maintain existing assets and keep essential services running. That leaves very limited scope for upgrades – and the consequences are restrictions on development, increased pollution risk and worsening pressure on the environment."

He emphasised NI Water's collaborative approach with councils, planners and developers to manage constraints and progress interim measures where feasible. Dr Blockwell said: "We recognise the impact that these constraints are having on housing delivery and economic development. We are looking at innovative solutions to remove unwanted water and working with local traders to address network and treatment capacity issues in the Lisburn area. Furthermore, our teams continue to work closely with the Council and with developers to find interim solutions where possible. But the reality is that many locations will require major capital upgrades before growth can proceed."