Lanes high-powered jetter relieves village flooding risk

Lanes for Drains engineers have saved a village near Bristol from the threat of flooding by cutting tonnes of calcite from a pipe taking spring water to the River Avon.

They brought in a trailer-mounted jetting unit that can deliver water at up to 15,000 PSI – up to twice the pressure of a conventional HPWJ machine – to blast the mineral deposits.

Engineers at the Lanes for Drains Bristol Depot in Burcott Road, Severnside Trading Estate, Avonmouth, were called in to tackle the problem in an area of Bristol close the River Avon.

A 900mm concrete pipe that takes water from a nearby spring to an outfall in the River Avon had become completely blocked. This caused regular floods, as the spring water backed up and inundated the gardens of local homes and roads.

Lanes for Drains, the UK’s largest specialist drainage company, used the high pressure jetter, combined with a special cutting head, to slice through the calcite which, in large deposits, can become as hard as stone.

Within two days, the pressure on the pipe was relieved and within three more days, the pipe was completely clear of the deposits – allowing water to flow normally.

Steve Britton, Regional Manager for the Lanes for Drains Bristol Division, said calcite blockages were common in the Bristol area – but this was one the largest they had dealt with in recent years.

He added: “The local rock is limestone from which calcite leaches into the water. Usually, the problem can be dealt with by cleaning with a standard jetter. But this was a particularly big build up. Lanes has high powered jetting units, specifically for this purpose.

“The pipe from the spring was about 120 metres long and a section about 30 metres long was affected. In places, it was completely blocked.

“I would estimate that it took only two years to build up. If you put a stick into the spring at its source, it becomes coated with calcite within a few minutes, there is so much of it in the water.”

Up to five tonnes of calcite was removed from the pipe, which was otherwise undamaged, and taken to a recycling centre. The mineral is often used in road foundations but is also an ingredient in toothpaste, glue and chewing gum.

Lanes’ high power jetters are also increasingly being used to quickly cut through tree roots that invade pipework, and smooth irregularities in pipes that can also cause blockages.