As part of its ongoing sewer improvement programme, NI Water has invested over £23 million over the last five years upgrading the existing sewer network so that communities across Northern Ireland are better protected against out-of-sewer flooding.

The rolling programme of sewer improvement work – carried out by GEDA Construction and AG Wilson Civil Engineering – has included repairs to over 30km of the sewer network from Banbridge to Bushmills and from Donaghadee to Derrylin.

The majority of the planned sewer improvement work is carried out by underground trenchless methods, involving the relining of sewers from existing manholes.

NI Water Senior Project Manager, Robert McLean explained:

“Working in partnership with AECOM and GEDA, the team works proactively to identify the highest priority areas of the network for improvements by undertaking CCTV surveys of existing sewers and analysing their structural condition, history of blockages and out-of-sewer flooding records.

“Where possible, rather than lay new pipes, the existing sewers are relined from connecting manholes. This effectively creates a new pipe within a pipe to strengthen the existing network and vastly reduces the amount of disruption within communities.”

The sewer rehabilitation/improvement programme also allows NI Water to address unplanned works which may be a result of an unexpected burst or collapse. Due to its nature, this work – managed by WSP and delivered by AG Wilson Civil Engineering - is more reactive and requires the speedy mobilisation of the contractor to ensure repairs are carried out as quickly as possible. In the last five years alone, around a quarter of the £23 million invested has been spent on unplanned sewer works across Northern Ireland.

Thanking the team behind the sewer improvement programme, Robert concluded:

“As we mark another five years of the programme, I’d like to pay tribute to our project team from AECOM, WSP, GEDA Construction and AG Wilson Civil Engineering and their supply chains who strive to deliver these improvements in a safe, efficient and low-impact way. I look forward to continuing our efforts to strengthen even more sections of the sewer network and deliver even further environmental and economic benefits throughout NI during the remainder of our current capital works programme.”

A summary of the planned sewer improvement works completed over last 5 years includes:

• 41,782m of CCTV investigations.
• 22,708m of sewers trenchlessly rehabilitated (underground improvements to reduce disruption)
• 590.3m of sewers replaced.
• 450m of new sewers installed.