Moor Road Flood Attenuation, Croston, Lancashire

As part of our 10-year Network Maintenance Service Framework with UU, Bethell were tasked with the responsibility for the design and construction of additional storm water attenuation in the Lancashire village of Croston so that several residential properties could be removed from the flooding register.

The solution involved the upsizing the diameter of 0.6km of existing sewer and linking the new pipework into a new underground tank which would provide an additional 800 cubic metres of temporary rainwater storage until the existing outfall sewers have sufficient capacity for the storm volume to be returned. The stored water is pumped from the new tank through high-volume electrical pumps and associated mechanical pipework.  

The upsizing of Moor Road sewers consisted of replacing 600 metres of 300mm pipeline with new 450mm pipe installed using no-dig techniques. It was preferential to install the new pipes using directional drilling to reduce inconvenience to local residents and also avoid excavating around a large number of underground services.  

One of the major elements of the project includes the 800 m3 capacity storage tank, installed in afield adjacent to Moor Road. The 15m diameter by 10m deep tank was constructed using precast wall segments, a 150m3 mass concrete base and a composite roof slab comprising both precast and insitu components. 

This fast-track scheme achieved a programme reduction of more than 6 months between the design and construction stages when compared with traditional design and construct routes. Our collaborative approach during the ECI stage and ‘can do’ attitude to overcome obstacles during the construction phase ensured that the scheme was completed within a tight OfWAT deadline helping UU avoid potential financial penalties.