United Utilities has appointed Barhale to deliver a storm overflow reduction project at Bramhall in Stockport, as part of its Better Rivers investment programme.
The civil engineering, infrastructure and tunnelling specialist will build a new detention tank at Bramhall Precinct car park to reduce how often the existing Briarlands Combined Storm Overflow operates into Micker Brook, a tributary of the River Mersey.
The scheme will intercept a sewer running into the existing CSO and increase local network storage during heavy rainfall. It forms part of United Utilities’ wider AMP8 investment programme, which includes work to reduce storm overflow spills and improve river water quality across the North West.
New storm storage planned for Bramhall
The project includes construction of a 1,000m3 shaft tank using a 12.5m diameter segmented caisson, sunk to an invert depth of 13.3m.
The site is located in an area with a high water table, requiring Barhale and United Utilities to work together on the design approach. The scheme also requires the diversion of an 825mm diameter sewer running at a depth of 4m to allow the new tank to be built.
Barhale will also deliver the MEICA fit out, including new pumps in the shaft, control equipment kiosks, control panels, telemetry systems and incoming power supplies. A dual rising main will connect the new infrastructure to the network upstream of the CSO chamber.
Reducing storm overflow spills into Micker Brook
The Bramhall project is intended to support United Utilities’ target to reduce storm overflow spills by 60% over the decade to 2030. The company says its Better Rivers programme will invest more than £3 billion in storm overflow infrastructure, with its wider 2025-30 business plan covering water and wastewater upgrades across the North West.
United Utilities says the programme is designed to protect and enhance more than 500km of rivers, as well as improving bathing waters and shellfish waters.
“The project presents some significant technical challenges because of the location and site conditions and we are pleased to continue supporting United Utilities as part of their wide reaching AMP8 investment programme,” said Nick Curtis, Regional Director, Northern Region at Barhale.
“We are already active across several aspects of the programme which are reinforcing the network’s ability to withstand storm events. They include constructing another smaller storm tank near this one in Cheadle and two more in Merseyside.”
The Stockport award follows previous Barhale work under United Utilities’ Better Rivers programme, including storm storage schemes in Cheadle and Merseyside. H2O Global News recently reported on Barhale’s triple project package under the Better Rivers programme.
“The investment is aiming to reduce spill rates to fewer than one-in-ten-year events. The completion of the Briarlands CSO programme will be an important step towards meeting United Utilities’ target of reducing spills from storm overflows by 60% before 2030,” Curtis added.
Completion of the Bramhall works is scheduled for early summer 2027.
FAQs
What is being built at Bramhall Precinct car park?
Barhale will build a new 1,000m3 detention tank to increase stormwater storage capacity in the local sewer network.
Why is the Bramhall storm tank needed?
The tank is designed to reduce the number of times the Briarlands Combined Storm Overflow operates into Micker Brook during heavy rainfall.
When will the Stockport project be completed?
Completion is scheduled for early summer 2027.
