Accommodating the permanent structures required
to operate the tunnel.
The multi-billion project to reduce sewage overflow into the Thames will involve construction in two sites along the river in and around Putney. The consultation documents were released today and include a proposal for a worksite to connect the local combined sewer
overflow (CSO), known as the Putney Bridge, to the main
tunnel of the proposed Thames Tunnel project and one on Barn Elms Sports Grounds.
In their consultation document Thames Water states:
We need a significant number of sites in order
to construct the Thames Tunnel project. Large
‘shaft sites’ are required at certain points along
the route to allow the construction of the main
tunnel. Smaller ‘CSO sites’ are also required near
each of the most polluting CSOs to connect them
to the main tunnel."
"We shortlisted four possible work sites on the
foreshore close to where the CSO discharges under
Putney Bridge. The configuration of the existing
drainage network and the high density of local
buildings meant the only viable CSO interception
locations are within the foreshore of the river and
therefore all of the sites are located within the Putney
Embankment Conservation Area. We assessed
the suitability of each site by taking into account
engineering, planning, environment, property and
community considerations. From this process we
identified our preferred location as the foreshore
site immediately to the west of Putney Bridge.
Site 1 – Foreshore, end of Brewhouse Lane and
Site 2 – Foreshore, adjacent to Putney Bridge and
St Mary’s Church.
Both sites located to the east of Putney Bridge
would be adjacent to the Grade II* listed St Mary’s
Church, The Boathouse public house and the
Use of site 2 could have a greater impact upon the
residential and commercial properties at Putney
Wharf Tower. These residents would be in closer
proximity to the works and would not benefit
from the highway separation that exists between
sites west of Putney Bridge and the associated
Site 3 – Junction of Lower Richmond Road and
This site is considered the less suitable of the two
sites west of Putney Bridge. It is located further away
from the CSO discharge point beneath Putney Bridge
and would therefore require increased construction
in the foreshore. The reduced clearance of the site to
adjacent amenities could cause greater disturbance
to residential properties and commercial buildings on
Lower Richmond Road and the bars and restaurants
on Putney Embankment.
Site 4 - Their preferred site is at Putney Bridge Foreshore
Their preference according to their consultation document :
" Compared to the
alternatives, the buffer provided by the road has the
potential to reduce the impact of the construction
works on the nearest residential and business
premises and users of the Thames Path. The shaft site
is located further away from Grade II listed Putney
Bridge and Grade II* listed St Mary’s Church than
two of the alternatives considered. It is also relatively
close to where the CSO currently overflows into the
River Thames. This preferred site would also provide
greater separation between the working area and the
Putney Bridge Pier to the west, thereby minimising
the impact of the works upon vessel movements and
navigation to and from the pier."
The CSO itself is located within the southern
supporting arch of Putney Bridge, all the possible
work sites would require works beneath the arch
and against the structure of the listed Putney Bridge.
Access from the local road network is possible but,
due to the space constraints, limitations would need
to be imposed on the size of vehicles that can get to
Thames Water indicate that the location as a construction
site would be required for approximately two years. It would then be
vacated as much as possible but a smaller area kept
secure for subsequent equipment installation. They propose that the construction traffic would enter and
leave the site at the location of the existing slipway
to reach Lower Richmond Road.
As the site would be located in the foreshore we
would need to construct a temporary cofferdam
around it to protect the works from the river.
Their plans include some above-ground structures
on this site after the construction work has finished - they propose to
extend the existing river wall to create a new area of
hard-standing. With a new, realigned, slipway
will be constructed as part of the work. The structures to be located on this new area would
include a ventilation column (approximately 10m
high and 1m diameter), along with a rectangular kiosk
(approximately 1.5m high, 1m wide and 3.5m long)
housing electrical and control equipment. They would leave the area around these structures
as hard-standing to allow vehicle and pedestrian
access to this new area of river frontage and the
Barn Elms is the preferred site to connect the local combined sewer overflow
(CSO), known as the West Putney Storm Relief Sewer, to the
main tunnel.In teh consultation document they state it is the preferred site because:
"This allows us to
combine the works for the construction of the main
tunnel with those required to connect to the local
CSO, sited on Beverley Brook. Combining all the works
in one location would help reduce the overall impacts.
As the Barn Elms sports fields site is a very large
area, our work site would only occupy a part of the
south-eastern corner of the site, adjacent to the river.
While this would temporarily disrupt the use of the
sports pitches in this area, and will have some effect
on recreational river users, we believe our proposed
works can be positioned to minimise this disruption.
We also believe we can provide suitable mitigation for
the potential impacts on the rowing and sailing club
and the scout hut and community hall located on the
eastern boundary of our proposed site."
Two other sites had been investigated; Leader Gardens & the boat worskshop on eth Embankment beside Leader Gardens, but they are more residential adn Thames Water believe Barn Elms would:
potential impacts of construction on the surrounding
community and minimise any impact on the Putney
Embankment Conservation Area. The site would allow good vehicular access to the local road network. We
are currently considering two route options. Option 1
would be a new dedicated route along the southern
perimeter of the sports field and connect to Rocks
Lane. Option 2 would be to share the existing access
passing through the sports field and connect to
Queen Elizabeth Walk. Option 2 would require a local
extension of the existing access route between the
Boat House facility and our proposed site. The access
options are illustrated on the plan on the previous
page. These options would avoid the general issues
associated with routing construction traffic through
narrow residential streets or the Putney Embankment
Conservation Area to the south of the site."
Thames Water will need to build a 25m-diameter circular shaft big enough to put the
machine used to dig this section of the main tunnel
into the ground and remove the excavated material.
Permanent use of the site -
Thames Water will propose above-ground structures
on this site after the construction work is finished.
Most likely a ventilation column
(approximately 15m high and 3m diameter) and a
building (approximately 10m high, 12m wide and
20m long) to provide ventilation and filtering of the
air in the tunnel.
Thames Water state that:
We would leave the area around these structures
as hard-standing to allow vehicle and pedestrian
access for maintenance. We could soften this with
Above is an example of how the site could look
after construction has finished. As part of our public
consultation we would like to know your views on the
permanent look and use of the site.
September 10, 2010