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Major infrastructure investments

At NI Water we have a unique and privileged role supporting health, safeguarding the environment and promoting a strong regional economy.

Delivering high quality water and wastewater services that Northern Ireland requires to meet the demands of a growing 21st century economy, will take time and will cost money. We are investing approximately £2m per week in water and wastewater services across NI. £1.9 billion has been invested in Northern Ireland’s water and sewerage infrastructure over the last ten years

Delivering an improved infrastructure within the budget constraints set for us is one of the most challenging jobs facing any organisation in the water and sewerage sector – but the achievement of our objectives will result in major benefits to public health, the environment and the economy.


Sewerage Rehabilitation Programme

Sewerage Rehabilitation Programme Night time sewer re-lining

The “Sewerage Rehabilitation Programme” is an ongoing programme of work that is part of NI Water’s commitment to providing an effective sewerage system across Northern Ireland and represents an investment of approximately £18 million over a 6-year period.

Due to the age of the sewerage network, there is an increasing need to carry out “rehabilitation” (repair and maintenance work) to ensure optimum service is delivered to customers. As part of the ongoing commitment to improving services to customers, NI Water has a long-term programme for the improvement of the existing sewerage network.

NI Water have an ongoing programme to undertake CCTV surveys of existing sewers to identify and prioritise parts of the sewerage system that require rehabilitation. We continually undertake repair and renovation of existing sewers, and replace sewers that collapse or are otherwise beyond their useful lifespan. Works on this major project are currently being delivered through a number of contracting partners, at various locations throughout Northern Ireland.

What will the work entail?

The work may involve the relaying, relining or repair of existing sewers. Wherever possible the work will be undertaken using specialist “no-dig” or “low-dig” methods, which minimise the amount of ‘open’ excavation required. This is to minimise disruption to the public, businesses and road users as much as possible. However, where these methods are not possible, work will be carried out by “traditional” open trench methods.

At some locations, the work may involve lane/road closures, which will be agreed with the Department of Infrastructure in advance. All appropriate signage will be in place to inform the public, and we will work closely with our contracting partners to ensure disruption is minimised as far as possible.

On occasions, due to the location and nature of the works it may be necessary to carry them out during the evening/night time hours. This may be to allow the works to be undertaken safely, protecting the safety of road users, the public and construction workers, or to reduce the impact on road users/businesses.

What benefits do these works provide?

When work is completed in a specific area, it will: -

  • Improve the condition of the system
  • Reduce the likelihood of sewer collapses and blockages
  • Reduce the associated likelihood of out-of-sewer flooding 
  • Reduce long term disruption to customers and road users as a result of ongoing maintenance
  • Reduce long term maintenance costs

NI Water fully realises that work of this nature can be unavoidably disruptive, more so at some locations than others, particularly where temporary road closures and traffic diversions are required. In partnership with our Project Managers AECOM, contractors Geda Construction, we will work closely with the Department for Infrastructure and other key stakeholders to minimise inconvenience and disruption to local residents, businesses and road users as far as practicably possible.

In addition to the planned work programme, NI Water also have an ongoing programme of unplanned sewer rehabilitation works. This entails more reactionary type works, which are often emergency in nature and are also carried out throughout Northern Ireland. Due to the nature of these works, there may be a limited amount of notice for the public as they are often undertaken to prevent a sewer collapse or property flooding.


Existing sewer requiring emergency repair

Bag it and Bin it – Help us look after the upgraded sewers!

NI Water spends approximately £2.5 million a year on clearing blocked sewers. We would like to ask for the public’s assistance in reducing these by not placing inappropriate items in the toilet, down a drain or into the sewers.

Find out more at



Sicily/Marguerite Park Flood Alleviation Project – Phase 1

NI Water has now appointed BSG Civil Engineering Ltd., as the main contractor for Phase 1 of this construction project. We will invest £8million over the next 2 years to increase the capacity of the existing network, substantially reducing the risk of out-of-sewer flooding and environmental pollution within the Marguerite Park area in the future.

What will the works involve?

We will construct over 1.3km of new larger diameter sewer ranging in sizes up to 1500mm.

The new sewer will be constructed from the ‘Grovelands’ area of Musgrave Park through the park grounds/Musgrave Park Hospital/Malone Integrated College, crossing under the railway line and through private lands into Diamond Gardens/Marguerite Park and Donegall Park. The section of sewer within the Diamond Gardens/Marguerite Park and Donegall Park areas will be laid using traditional ‘open-cut’ excavation methods due to the number of existing underground services in this area.

Tunnelling works

Around 800m of the new sewer will be constructed using trenchless ‘tunnelling techniques’, which will include tunnelling under the main Belfast to Dublin rail line. This method of construction will substantially reduce the disruption to the public within Musgrave Park/ Musgrave Park Hospital and Malone Integrated College.

What it the timescale for the project?

Site preparation works will commence within the grounds of Musgrave Park & Musgrave Park Hospital in March, with the main construction works due to get underway in April 2021. We anticipate that it will take up to 2 years to complete all work.

The sections of sewer within the Diamond Gardens/Marguerite Park and Donegall Park areas are currently programmed to commence in Summer 2022, subject to progress on other sections of the project. We will issue further progress updates as the work progresses, and liaise with residents within these areas prior to the works commencing. 

Phase 2 – Sicily Park Flood Alleviation

The out-of-sewer flooding in the Sicily Park area will be addressed by Phase 2 of this project. The commencement of this phase is dependent on the completion of a separate, long-term project to extend the ‘Belfast Storm water Tunnel’ to Musgrave Park. Funding for Phase 2, and the tunnel extension project, has been applied for in NI Water’s ‘Living With Water Programme’* funding requirement, which was submitted to the NI Utility Regulator at the same time as our ‘PC21’ funding requirement**.

NI Water will continue to monitor the sewerage network within this area, particularly during periods of heavy rainfall and undertaken any routine maintenance required. In combination with previously completed drainage infrastructure improvements in the area, this will help reduce flood risk in the Sicily Park area until the Phase 2 works are completed.

NI Water would like to thank local residents for their ongoing patience throughout the development of this significant and challenging infrastructure project.

* Living With Water Programme - A multi-agency initiative headed by the Department for Infrastructure to develop a Strategic Drainage Infrastructure Plan (SDIP) for Belfast to support economic growth, protect the environment and address flood risk.

** PC21 funding requirement – NI Water Capital Works Funding Programme, which covers the period 2021-2027.


Belfast Watermains Maintenance Programme

Belfast Watermains Maintenance Programme

NI Water staff and contractors will be undertaking an essential programme of Watermains maintenance throughout Belfast during August/ September 2020.

Please see estimated dates and locations below. Please note they may be subject to change:

Flushing Installation



Number of Nights

Start Date

End Date


Twaddel Ave










Finaghy Halt South





Endfield St





Manor St





Flax Street






We are cleaning and maintaining the watermains network by flushing, which involves opening fire hydrants in a phased sequence to flush out any sediments.


Over time, sediments can build up on the inside of our watermains, which can result in customers receiving discoloured water. To reduce the likelihood of discoloured water, we are carrying out a programme of work to clean our local distribution mains. The flushing programme is an effective way of preserving existing infrastructure, preventing future issues and improving services to our customers.


Flushing allows naturally occurring, harmless mineral deposits inside the network to be removed. While these deposits are not harmful, they can discolour the water.

To minimise disruption, this work will be carried out during the night and involves opening fire hydrants to safely flush out any accumulated sediment. You may notice personnel on the street carrying out this work and we will cordon off our apparatus in advance of flushing works to protect the public. All our employees carry company identification and welcome your enquiries.

While our work will be undertaken at night, there may be some light background noise through fire hydrants being operated, but we will do everything possible to keep disruption to a minimum.


If you are affected, you will receive a letter and to minimise any inconvenience, during the dates on your letter, we recommend the following:

  • Fill your kettle, or a suitable container with drinking water before work starts
  • Don’t use washing machines, dishwashers etc. or leave taps open
  • Don’t use mains fed instantaneous water heaters/showers if the water supply is interrupted (central heating will be fine)
  • If you have a water softener, isolate it using the bypass pipe work until the flushing is completed
  • Do not fill or change the water in fishponds or tanks for 48 hours.

NI Water would like to assure customers our number one priority is the quality and safety of the drinking water we provide. Your water will continue to be safe to drink at all times, but on the dates between the start and end of the flushing you may experience some temporary effects such as,

  • Discoloured or cloudy water
  • Low water pressure
  • Short interruptions

Water is often discoloured after watermain flushing, but this should not last long. In the event customers draw discoloured water into the home, run a cold tap for a few minutes and this should clear. As a precaution, prior to using hot water, run the cold water tap to ensure discoloured water is not drawn into the hot water tank. You do not have to boil the water before use; it is safe to drink at all times.

Bogus callers

We would like to remind all customers to be vigilant regarding bogus callers.  Bogus callers pose as staff seeking to gain entry to check the water supply in the customer’s property, or causing distraction while an accomplice breaks in. Once they have gained entry they will distract the customer and try to steal valuables lying around the home. 

If a caller comes to your door claiming to be from NI Water, Water Service or the Water Board, always ask to see their ID – all NI Water staff carry ID cards as they go about their business. This will have a photograph of the person carrying it and includes details such as their name, a unique serial number and our distinctive NI Water logo. Also, attach your door chain, if you have one; if not, ask the caller to hold the ID card up to a window or put it through your letterbox so you can read it properly without opening your door.  Please do not be afraid to check a caller’s ID; genuine callers from NI Water won’t mind waiting while you do. Never allow anyone into your home unless you are certain they are who they say they are.

We would like to thank residents in advance for their patience while we carry out this work.


Bangor Sewerage Improvement Project

Bangor Sewerage Improvement Project Brompton Pumping Station

NI Water are due to undertake a £4m programme of work to replace ageing wastewater pumping stations at Brompton Road and Stricklands Glen as part of the latest phase of a wider multi-million-pound investment to improve water quality along the North Down coast.

Stricklands Glen Pumping Station 

The scheme, which is due to get underway in full in early April, will also involve the upgrade of the associated sewerage network to help prevent out-of-sewer flooding in the future.

For further details click on the links below:


Drumaroad Water Treatment Works £13m Upgrade

Drumaroad Water Treatment Works £13m Upgrade Aerial view of the Drumaroad WTW Upgrade

A £13 million investment at Drumaroad Water Treatment Works (WTW) Castlewellan is currently underway.

This programme of work is progressing well and involves the construction of a new water storage tank on site, which will provide improved water services to customers, particularly during emergency situations, as well as improving the security of the water supply and drinking water quality.

Drumaroad WTW is a key water supply site, which treats water from the Silent Valley Reservoir and supplies around 140 million litres of water per day to over 200,000 homes in County Down and Belfast. This means that approximately one quarter of Northern Ireland’s population will benefit from this upgrade that will increase the resilience and security of the water supply, particularly in emergency situations.

The new water storage tank will serve the existing Drumaroad Water Pumping Station and Chapel Hill Water Pumping Station to supply treated water to the catchment area. An additional Pumping Station will also be constructed to transfer flows outside of normal operating conditions.

Graham Construction is the main contractor for this major programme of work, with RPS providing project management and technical support.

The project will bring great benefits to the local water infrastructure and is scheduled to be completed in Summer 2021.


Upgrade of Benone Vacuum Sewerage System

Upgrade of Benone Vacuum Sewerage System Benone Tourist Complex WwPS

Work is progressing well on a £2.1m NI Water investment to improve the performance of the sewerage network in key tourist areas of Benone.


The Benone Vacuum Sewerage System was installed in the early 1990s. Consisting of 60 valve chambers and 6,000m of sewers, the system serves local caravan parks, tourist amenities and a small number of private houses. In addition, flows from the Downhill area are also pumped to the Benone vacuum system. It was originally designed to cope with a summer population equivalent (PE) of 2,250 and a winter PE of 120, but figures show that in recent summer months the population equivalent in the area has increased to more than 3,300. The increase in visitors to the Benone area during peak tourist seasons, coupled with unseasonal heavy rainfall, mean that on occasions the existing system struggles to cope with the pressures being exerted on it, resulting in a high level of call outs from NI Water.

Need for upgrade

Vacuum sewerage systems consist of sealed structures designed only to transfer sewage to either a wastewater pumping station or a treatment works, and are not intended to convey storm (surface) water. If, during heavy rainfall, the system becomes overwhelmed – due to infiltration – it can lead to a loss of vacuum and result in localised out-of-sewer flooding.

To address the problem, NI Water undertook an appraisal of the existing Benone vacuum system and work is well underway to complete a £2.1m programme of work to enhance the performance of the network to meet present and future needs.

NI Water and its design team developed a solution that optimises the performance of the network with minimal impact on local amenities.

The solution involves replacing the majority of the existing valve chambers with conventional sewers and the introduction of new wastewater pumping stations (WwPS) which will reduce the hydraulic loading on the network. The small section of the vacuum system being retained along the Seacoast Road and in part of one caravan park will be enhanced to improve reliability and accessibility.

A total of 5 new WwPS will be constructed at strategic locations in the network:  Benone Tourist Complex; Benone Avenue North and Benone One Transfer have now been completed, with work on schedule to complete Golden Sands and Benone Avenue South Pumping Stations by Easter 2021.

New pumping mains and sewers will be included in the scheme to allow these new pumping stations to connect to a new terminal pumping station adjacent to the Benone vacuum station; which in turn will utilise the existing twin pumping mains to transfer flows to Aughil WwPS and on to the new wastewater treatment works at Magilligan.

Benone One WwPS

Benone Ave North aerial

Benefits of the scheme

Once complete, this major scheme will provide a more robust sewerage network, capable of coping with an increased number of tourists to caravan parks and local amenity areas in Benone.

The introduction of conventional wastewater pumping stations will reduce the likelihood of out-of-sewer flooding and provide a more reliable system that will require less operational maintenance.

NI Water and our project team appreciate the support of local landowners and other stakeholders in developing a suitable, cost-effective solution that meets the needs of a wide section of the tourism industry in Benone. We would like to thank the local community for their patience as we complete this essential project.


The Living with Water Programme (LWWP)

The Living with Water Programme (LWWP)

The Living with Water Programme (LWWP) is a multi-agency initiative headed by the Department for Infrastructure to develop a Strategic Drainage Infrastructure Plan (SDIP) for Belfast to support economic growth, protect the environment and address flood risk.

As coordinator of the programme, DfI currently works collaboratively with a number of partner organisations, including: NI Water; DfI Roads and Rivers; the Northern Ireland Environment Agency (NIEA); the Utility Regulator; Belfast City Council; Department for Communities (DfC); and the Strategic Investment Board (SIB).

Find out More


Ballygowan Wastewater Treatment Works

Ballygowan Wastewater Treatment Works

A major £6.4 million programme of work to construct a new modern wastewater facility at Ballygowan is now underway.

This major investment will significantly improve wastewater services for customers and accommodate future economic growth and development in Ballygowan and the surrounding area.

Once complete, the new plant will benefit a future population of around 4,500 people and will also bring about key environmental improvements, such as improving the water quality in the River Blackwater.

NI Water and our project team, including Geda Construction, Water Solutions Ireland and Tetra Tech would like to thank the public for their patience and cooperation throughout construction work on this essential new treatment plant. We assure customers that we will do everything possible to minimise disruption throughout the contract.


Ravenhill Avenue Flood Alleviation Project

Ravenhill Avenue Flood Alleviation Project

NI Water will soon commence work on a major Flood Alleviation Project in the Ravenhill area of South Belfast in February 2021.

This work will address the lack of capacity in the sewer network and reduce the risk of out-of-sewer flooding, as experienced by some homes and businesses in recent years. Many of the sewers in this area are old brick sewers dating back to the early 1900’s and are in very poor condition.

We will be replacing and upgrading 2km of sewers, as well as removing large amounts of rainwater from the existing combined sewers and returning directly to the River Lagan.

Work will take place at the following locations:

  • Ravenhill Road
  • Ravenhill Avenue
  • Sunwich Street
  • Millar Street
  • Federation Street
  • Ormeau Park

Click here to take a tour of our virtual information room

When complete, this project will significantly reduce the risk of flooding and environmental pollution as well as providing additional capacity for future development.

Unfortunately, due to ongoing restrictions in relation to the Covid 19 pandemic we are unable to hold a public information session prior to the commencement of these essential works.

However, along with our partners AECOM, we are developing a ‘Virtual Information room’, which will provide detailed information on the project, and the phasing of construction works. This will be available soon, and will be updated as the work progresses.

We are working in partnership with our consulting and contracting partners AECOM and Geda Construction to deliver these essential works.

We would like to thank all local residents, business owners and commuters for their co-operation and patience during this challenging programme of work.


Water Mains Rehabilitation Project

Water Mains Rehabilitation Project

As part of the ongoing commitment to improving our services to customers, NI Water has a long-term programme for the improvement of existing water mains. Much of our water mains system is between 40 and 150 years old, it is generally in poor condition and needs to be replaced

NI Water aims to upgrade the ageing water mains system by renewing pipes and addressing problems such as bursts, poor pressure and leaks. Work is also necessary to improve water quality, to ensure sufficient capacity to meet future demands and to comply with all current National and European environmental regulations.

The current phase of the Water Mains Project will cost approximately £114million, which will be invested in laying approximately 905km of water mains right across Northern Ireland. Customers may experience a reduction in water pressure or an interruption to supply whilst work is being carried out. NI Water apologises for any inconvenience. Customers can call NI Water on 03457 44 00 88 for further updates.

Discoloured water can occur when the mains are disturbed. This can happen when there has been an interruption to supply following a burst main and the operational activity associated with the repair. The discolouration will be short-lived, and running the tap for a while should help clear it from the system.

All water is disinfected to ensure it is safe to drink. Following operational activity, the level of chlorine in the water supply may be boosted temporarily. The amount of chlorine is carefully controlled and monitored at our treatment works and strategic points in the distribution system.

Water quality samples are taken following burst mains repairs to ensure that a satisfactory water supply is restored to customers.

To download the Customer Guide water Mains 2016 here

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