Water and waste company Severn Trent has trailed a flood grout on a flood alleviation scheme in Gloucestershire.
The £1.4M scheme in Slimbridge saw the water firm applying ‘flood grout’ to 600m of sewer pipes as part of a UK trial of the method.
Flood grouting is a method which uses two different grout materials, which are inserted into the sewers in stages.
The grout flows through the damaged sections of pipe, into the surrounding soil particles and then hardens around the sewer pipe when the two grout materials mix together.
The technique gives a near-perfect water tightness and seals any defects, while also stopping any groundwater from leaking into the network.
Severn Trent project manager Ian Woodward said: “Slimbridge is an area which is prone to flooding and we’ve seen problems in the past where ground water has mixed with sewage.
“It was the perfect location for the trial and we renovated 1.4km of pipes in three separate phases, with 600m of those being used for the flood grouting trial.”
As well as trialling the flood grout technique, the project also involved using other traditional trenchless technologies, including sewer lining, to renew the ageing sewer pipes.
“The initial findings are really positive. Monitoring of both the local sewage pumping station and the ground water levels in Slimbridge is showing that the grouting has been successful in keeping ground water out of the sewers in a really vulnerable area.”
According to the firm, this is the first time it has used this particular grout technique, and the company will continue to monitor the effectiveness of the trial over the coming months, during which time the ground water levels will vary.