The Wessex Water Flume Weir at Poorhouse, near Bradford on Avon had failed due to a leak around the wing wall. The leak had eroded the bank behind the right hand wing wall to such an extent that a large void had formed.
This meant that this section of stream bank would have to be rebuilt. To enable this, a temporary coffer dam was installed to divert the flow around the works. An excavator was then used to dig down behind the wing wall to a depth below the existing leak and then batter the landward side of the excavation to a slope of 45 degrees.
The back of the wingwall was then cleaned, inspected and repaired. Bentonite powder was then used to dress the back of the wingwall and sides of the excavation. Clay was imported and used to rebuild the bank and backfill the void.
A roller was used to compact the clay in layers. The upstream section of the bank was faced with concrete filled sandbags and reinforced with steel pins, to provide erosion control.
The gauge board was replaced with a new one fixed to a galvanised mild steel post driven in to the stream bed. The new gauge board was levelled into a stored datum to avoid the need for recalibration of the monitoring equipments. The work area was reinstated and seeded with a suitable grass seed mix.