In an effort to maintain flood defence abilities of a drain that had been categorised as requiring further action to sustain its level of flood risk into the future, Stonbury completed works to safely relocate and exclude badgers from an existing sett.

Inspection highlighted that the flood defence had fallen below its target asset condition score due to the presence of a badger sett within the embankment. The team were required to construct an artificial badger sett and exclude badgers from the existing sett before destroying it. The scope also included strengthening the embankment and safely excluding badgers from returning with permanent steel meshing and ongoing monitoring.

Initially, temporary exclusion mesh was installed over the existing sett to encourage the badgers to move to the artificial sett. Following a 21-day exclusion period, the team returned to site to commence works. A fabric barrier was fitted along the water edge to prevent soil rolling into the watercourse and the team began deconstructing the old sett. The previous exclusion meshing, ground pins, and one-way badger gates were taken out and set aside for re-use.

The area was prepared for permanent meshing by stripping the topsoil for 100 linear metres to a depth of 150mm - this was stored for re-use. The team then began to deconstruct the existing tunnels. All tunnels were collapsed and chased back to their ends. The estimated length of the tunnel section was 30 linear metres.

An imported clay core was then installed in compacted layers to ensure the bank could withstand the pressure of raised flood water and achieve the correct flood resilience. The existing topsoil was then returned and the team re-laid the previously removed mesh in one-metre-deep sections at each side as per the client’s design specification. The permanent meshing was then secured with the re-used ground pins, and any remaining gaps were re-proofed.

The team compacted the excavated topsoil to a depth of 150mm. The embankment was backfilled and reprofiled to match the adjacent profile and seeded with the client’s recommended grass mix for embankment usage. Continuing maintenance works are scheduled for a year to ensure good grass coverage is achieved with adequate bank stability.

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