Vital water treatment infrastructure benefits from erosion protection solution to guard against future flood contamination
Maccaferri’s flood prevention project at Tewkesbury at the Mythe is complete. The project involved the construction of a double faced gabion wall capped with a Reno Mattress top to protect the flood bund at the River Mythe Water Treatment Works.
Severn Trent Water invested £5.5 million to secure Gloucestershire’s water supply following the floods in previous years which had caused damage to the water treatment works. The floods in 2007 were a civil emergency which caused major disruption. The water works supply 160,000 properties in Gloucester, Cheltenham, Tewkesbury and the rural areas of Gloucestershire. It took two weeks for some households to regain use of their mains drinking water.
At Maccaferri, we carried out a design covering the stability of a gabion face which would cover the existing soil structure. We needed to provide a new, low maintenance surface which could withstand hydraulic erosion forces better than the original vegetated face.
The solution chosen was woven mesh gabion walls, which would stand each side of the original bund. The double twist steel wire mesh gabions were to be heavily galvanised and have an additional polymeric coating to deliver a long design life.
In addition to the gabions a 300mm thick Reno Mattress was placed over the existing crest of the bund to increase the freeboard above maximum static water level for additional security against over-topping.
Maccaferri Construction was appointed as specialist installer for the construction of the gabion protection structure and the works were completed in 15 weeks.