Permanent Siphon Installation at Knipton Reservoir

Knipton Reservoir lies within the grounds of Belvoir Castle in Grantham, and was originally designed to feed the Grantham Canal.

EDS was asked to install four siphon lines to increase drawdown capacity at the reservoir and assure public safety in the event of a flood. With the differing levels of the reservoir bed, accuracy in the installation was paramount. A range of specialist skills and equipment was used by the EDS team to achieve this.

Key Challenges:

  • The four siphon lines had to be connected to 66 concrete anchor blocks, all with pre-set levels
  • The reservoir bed was made up of soft silt and had large undulations
  • The finished levels had to be within a 50mm tolerance
  • Slabs and anchors needed to be positioned at the correct level
  • Four duck bend inlets were to be installed with concrete slabs at the inlet weighing up to 1.5T each

Solutions:

  • GPS equipment was used to verify installation levels and locations
  • Due to poor visibility, a scaffold system was used as screed rails so the dive team could level the stone fill. The team then placed each element prior to pipe installation
  • A NATO pontoon system was deployed with a 5T lifting gantry and dive spread, allowing all materials to be lifted onto the water
  • A six-point temporary anchor system was installed to allow precise movement of the barge and assist with placing the concrete anchor blocks

All pipes were installed within 15mm of the design levels — another successful project completed by the EDS team.