The project involved the upgrade of lake access ready for the 2012 Olympic games which included the replacement of the existing cut through bridge with a 20m wider finishing line bridge.

The programme was extremely tight with several critical deadlines starting with Land and Water Services installing the sheet piles (below) in one day for the temporary Bailey Bridge abutments to be installed thus providing access for the old bridge demolition process.

Two cofferdams were installed using Land and Water Services Movax piling rig following footpath and services diversions. These cofferdams were excavated, steel support frames and braces installed, dewatered and blinded, then handed back to the formwork contractor. Once abutments were constructed these cofferdams were backfilled and the sheet piles extracted. Once the new bridge deck was cast, Land and Water Services excavated underneath to form new bank revetments.

Further cofferdams, as above, were installed for the new bridge requiring a reduced dig to level, once abutments were cast, five rows of gabion baskets were filled and fitted to the exposed abutment sides (inside the cofferdams), backfilled and then piles removed.

The lake banks were re-profiled to 1:3 slopes, covered in topsoil and Tansar 200 geotextile was pinned to the surface and hydra seeded. Despite the volume of works required, the extreme weather conditions in the area Land & Water along with other contractors made great efforts to finish within one day of the finishing date.

Oak posts were braced in the trench and concrete poured to stabilize, oak boards were then fixed to the posts to form a continuous  revetment system. Top soil was back—filled on the outside of the lake between the boards and the inside of the liner to create a growing medium. An oak Jetty was constructed by setting the upright oak posts in concrete and waterproofing to the liner.

On completion, a layer of shingle was laid over the inside of the lake to hide the liner. And to achieve a high level of water clarity Land & Water Services were the Principle Contractor for the project with Johnny Glover as the Contracts Manager.

The designer was Casper Gadd of Natural Elements Design LLP. The site was levelled and compacted with the excavated material won from the lake and used to make up the ground to achieve an earthworks “balance” Having excavated the lake, 50m x 30m, an anchor trench was installed to take the underlay, reinforced liner and protective overlay.