Silt pumping work underway on South Forty Foot Drain

Black Sluice IDB have commenced major enhanced maintenance works on the South Forty Foot Drain upstream of Boston in Lincolnshire. The work is taking place thanks to financial backing from the Environment Agency who are partners in the works through a Public Sector Co-Operation Agreement (PSCA) with the IDB.

Works commenced in February removing mature bushes and trees from both banks. Once this had been completed a specialist 45 ton long reach excavator worked in tandem with a smaller spider excavator. This machine could ‘walk’ its way along the bottom of the riverbed and pass extensive root growth and blanket weed it had collected to the larger machine in order to remove it from the river bed.

The vegetation removal work has now given way to a specialist silt cutting and pumping dredger from the Netherlands, which has been lowered into the river to commence removing the c60,000 m³ of silt from the 11Km length of river being worked on. The silt and water mix is being pumped into a number of c4Ha silt lagoons where the silt settles and the clean water is fed back into the river. The benefit of this technique is that silt can be pumped up to 3Km between the cutting head and lagoon location, requiring far fewer machine movements to complete the work.

A detailed report of the works will be included in the ADA Gazette later this year. Please visit www.blacksluiceidb.gov.uk for an ‘open day’ invitation later in the year where you can visit site to watch the specialist cutter suction dredger in action and be introduced to this new system that could revolutionise inland water river bed silt removal as our industry currently knows it.

---