Flood Defence Outfall Refurbishment

This project was to re-furbish an outfall on the River Stour and improve the access arrangements to it for future maintenance.

The structure of the existing outfall had been compromised through age and freeze thaw weathering and so a new layer of reinforced concrete was to be cast over the existing structure.

Two new sets of steps were incorporated into the design to enable safer access to the outfall for future maintenance and the residents of the adjacent houses were to be provided with a new fenced area to store their bins.

The access was very tight down a narrow cul de sac lane to some houses. A long reach excavator was required to reach over the flood defence wall and work on the structure. In order to carry out the works this machine had to sit on the pumping chamber that fed the outfall and so a temporary works to design protect the chamber and spread the load of the machine was devised.

A temporary dam was installed in the river to keep the working area dry and a pump was set up to deal with the seepage through it.

The pipes from the pumping chamber that discharge onto the outfall were extended over the temporary dam to keep the working area dry in case of rain during the construction works.

The existing structure was cleaned and prepared to receive the new concrete before the reinforcing was installed.

The formwork was constructed around the existing structure and the new concrete was poured.

Once the concrete had cured sufficiently the formwork and temporary dam could be removed.

The two sets of steps were then installed, the new bin store was constructed and some other fencing to deter public access was erected.