Two major projects are planned to improve the flow of sewage to the treatment facilities, and to prevent the discharge of sewage into the river, and into buildings during periods of heavy rainfall or snowfall. Both of these essential projects will have a major impact on local residents in the Lots Road area of Chelsea Riverside Ward, and a lesser impact in Royal Hospital Ward.
The Chelsea Society would like the impact on local residents is kept to a minimum, and the locality to be restored to its present state or improved. We will work closely with local residents’ associations and RBK&C as well as with Thames Tideway Tunnel Ltd and Thames Water, throughout these projects.
A. THE THAMES TIDEWAY TUNNEL PROJECT
Thames Tideway Tunnel Ltd will be a new regulated utility company that will design, construct and finance a new 25 kilometre tunnel under the tidal River Thames in London, to prevent an average 20 million tonnes each year of untreated sewage discharging into the river.
The company will have its own licence with revenues determined by the regulator OFWAT, and will collect bill payments for the tunnel via Thames Water. Thames Water will continue to provide water and wastewater services to its customers as it does now.
Thames Tideway Tunnel Ltd will enter into contracts with construction companies for three geographical areas in east, west and central London, to build the project. When formed, the company will receive support from Government against exceptional risks, which is intended to reduce the cost of the project and reduce the bills for customers.
The Thames Tideway Tunnel project will be developed by Thames Water until the conclusion of the competitive procurement process, expected to be in May 2015. Key members of the Thames Tideway leadership team have already been recruited, including the chairman Sir Neville Simms and the CEO Andy Mitchell.
TWO SITES ARE PROPOSED ON THE SURFACE IN CHELSEA
1. Cremorne Wharf Depot
This site comprises the existing council depot, the Grade II listed Lots Road Pumping Station, and a part of the Thames foreshore. The site will intercept the Lots Road Pumping Station combined sewer overflow (CSO).
Work will require the demolition of the existing depot building and the construction of underground structures, to connect the CSO to a shaft approximately 42 metres deep with an internal diameter of approximately eight metres. This shaft will be built in the land between the existing pumping station building and the river wall. It will transfer sewage flows from the CSO to the main tunnel.
Construction is expected to start in 2017 and will take approximately three years. Some advance works may be carried out before the main construction period. On completion of the works the site, subject to the agreement of RBKC, will be returned to use as a council depot. The Greater London Authority has designated it as a “Safeguarded Wharf” together with a number of other wharves on the Thames.
2. Chelsea Embankment Foreshore
This site is on the northern bank of the River Thames opposite the Royal Hospital Chelsea Bull Ring Gate. It comprises an area of the foreshore, a section of footway and carriageway of Chelsea Embankment (A3212) and a small part of Ranelagh Gardens.
This site intercepts the existing local combined sewer overflow (CSO), known as the Ranelagh CSO, and connects to the northern Low Level Sewer No.1 to divert flows to the main tunnel. These works, along with works at Blackfriars Bridge and Victoria Embankment, mean that no additional sites will be needed to intercept ten CSOs between Battersea Bridge and Blackfriars Bridge.
There will be a new area of reclaimed land on the foreshore, and underground structures to connect the CSO and the low level sewer to a shaft approximately 45 metres deep with an internal diameter of approximately 12 metres. The shaft will transfer sewage flows from the CSO to the main tunnel.
While most of the operational structures will be underground or within the new foreshore structure, several ventilation columns and two electrical and control kiosks will be permanent above ground features.
Construction is expected to start in 2017 and will take approximately four years. Some advance works may be carried out before the main construction period.
B. COUNTERS CREEK STORM RELIEF SEWER
This will be built by Thames Water, to connect the existing sewers running through the Counters Creek catchment area into the proposed storm relief sewer at five locations known as interception sites. The route map and time-line can be seen at http://www.thameswater.co.uk/counterscreek/Timeline_and_Proposed_sewer_line.pdf
Thames Water has launched an interim consultation for new sites (none of them in Chelsea) for the Counters Creek Sewer Alleviation Scheme. See http://www.thameswater.co.uk/counterscreek/
This phase of interim engagement runs from 11 May to 8 June 2015.
The proposed storm relief sewer will be approximately five kilometres long, four metres in diameter and at its deepest point almost 40 metres underground. It will collect excess storm-water from the five interception sites and store it until the storm has passed. When flows in the network return to normal, the water will be pumped back into the sewer network and onwards to Beckton Sewage Treatment Works in East London.
The interception sites are also the construction sites needed to build the sewer.
On 7th April 2015 Thames Water advised local residents as follows: “During our first phase of consultation, driving the new sewer from Cremorne Wharf was our second choice. We have since learned that our first choice (using the car park at Kensington Olympia) is not a workable option. We are now focussing our efforts at Cremorne Wharf and the use of barges to bring materials in and out from the site.” There is an explanation of the changes and the reasons for them at http://www.thameswater.co.uk/counterscreek/17335.htm
During a four week period in May and June 2015, Thames Water will seek comments on several additional potential construction sites. Residents who live close to these sites will be notified by letter and invited to comment on the proposals.
They say that all comments received during this period will be added to those already received, and their responses will be published and placed on their website ahead of the second phase of consultation planned for late summer 2015. A planning application is expected in November 2015 and construction of the sewer is intended to take place between 2017 and 2020.
This is the same timescale as already envisaged for the Thames Tideway Tunnel work at Cremorne Wharf, and we would welcome integration between these two major projects to reduce overall costs and lessen the impact on the local community by shortening the years of disruption, traffic congestion, noise, dirt and pollution.