Work has started to release temporary cofferdam structures constructed into the River Thames at Thames Tideway Tunnel sites across London.
Cofferdams are being terminated at locations such as Albert Embankment in Vauxhall and King Edward Memorial Park in Wapping.
This removal has permitted water from the Thames to flow against the new river walls and riverside architecture for the first time while also showing more of the public spaces that will be left behind when construction is finished.
Cofferdams are momentary areas of land constructed out into the river with metal perimeters to give the required space for sewer construction.
At multiple sites, this also concerned the giant shafts’ construction through which equipment like TBMs could be lowered below ground. In addition, these shafts boosted the installation of vortex structures to take sewage flow once the tunnel is functional.
At Albert Embankment, openings have been made in the cofferdam sheet piles to enable the flooding of two of three cofferdams.
This plan will equalize the water pressures on both sides of the walls to enable the safe cutting and pulling of the sheet piles. Terrace planting has already been installed on the new floodable intertidal public spaces becoming visible behind the cofferdams.
The cofferdam removal works have also started at King Edward Memorial Park. When the sheet piles are removed more of the new river wall will be shown with its specially built “boxy” design that will satisfy a range of wildlife, ranging from crabs to algae.
Tideway, the corporation constructing the super sewer, revised the cost estimate for the overall project to £4.5bn in April, taking account of the remaining work program and the effects of inflation. Since 2014, the project cost has surged from the primary estimation of £3.52bn.
The scheme remains on course to be completely operational in 2025 and is anticipated to be delivered to Thames Water in the second quarter of that year. Nevertheless, sewage overflows will begin to be redirected away from the Thames into the new sewer tunnel next year.
