
Raised land levels
With flood modelling predicting an increase in future rainfall volume and intensity, and an ageing drainage system unable to deal with surface runoff, the new pumping station is part of multi-agency flood risk reduction plans in the area.
The station will remove surface water caused by heavy rainfall and discharge it into the River Don.
The pumps can operate at a claimed 3000 litres per second, emptying the equivalent of an Olympic-sized swimming pool in just 14 minutes. The project involved land levels being raised by 2.5m to reduce the risk of flooding to the facility (see photo left).

Challenging conditions
Close proximity to the river meant the risk of flooding was a constant challenge which had to be managed throughout the works. Breheny followed their Construction Phase Plan and installed the appropriate sheet piling and laid sandbags along the roads. The measures taken were a success and flooding was avoided. Breheny used Ground Penetrating Radar (GPR) to produce a 3D image of entities below ground level, avoiding existing ground disturbance. This technology enabled accurate location of both natural and man-made objects underground allowing redundant electrical cables to be capped and a water mains diverted. The completed survey reduced risks and improved safety.

Lightweight backfill
During the pre-construction phase Breheny worked with the design team and council to identify a lightweight backfill material to utilise against the abutment walls of the new pumping station.
In addition to being lightweight, the backfill also needed to be high-strength as the pumping station had differing levels to either side of it giving rise to a large, horizontal resultant force. Following extensive research, it was decided that LECA® LWA was the best solution as this would provide a light density fill but would still be able to carry the live load surcharge, removing the need for more expensive alternatives such as horizontal piling.

New outfall
Breheny also constructed a combined sheet pile and concrete headwall into the River Don, using divers to cut the piles underwater. The project further included: electric sub station, a free-standing jib crane, control kiosk, stand-by generator and lighting with installation of CCTV columns and cameras. New culverts were constructed and improvement of existing drains was undertaken. Finally, a new section of tow path which forms part of the national cycleway network was reconstructed.

Social value and community support
The scheme delivered £372,751 of social value, an improvement of over 650% on the original target committed during tender stage.
Breheny organised and ran a four-hour workshop on site for locally unemployed, and employed two people. The local supply chain also benefited with £500,000 going to businesses and suppliers in the area.
Members of the team volunteered to support Rotherham Borough Council’s Safety Advisory Group to further promote safety within the community, and the pumping station scheme was selected as exemplary for the Council’s Social Value Stories.
Breheny received Highly Commended from the CECA Y&H Annual Awards for their work on the pumping station.