COUNTRY | United Kingdom
REGION | Europe
SECTOR | water and waste
SUB-SECTORS | dams and irrigation
QII Principles | Principle 1 Sustainable Growth & Development, Principle 2 Economic Efficiency, Principle 3 Environmental Considerations, Principle 4 Building Resilience, Principle 5 Social Considerations, Principle 6 Infrastructure Governance
QII Sub-Principles | 1: SDGs, 1: Paris Agreement, 1: Wider economic benefits, 2: Value for money analysis, 2: Life-cycle costing, 2: Operation and maintenance, 2: Technological innovation, 2: Risk management, 3: Environmental Impact Assessment, 3: Disclosure of environmental aspects, 3: Ecosystems, 3: Biodiversity, 3: Climate, 3: Weather, 3: Emissions, 4: Resilience, 4: Disaster risk management, 4: Disaster risk insurance, 5: Social Impact Assessment, 5: Job creation, 5: Capacity and institutional building, 5: Occupational health and safety, 5: Universal access to services, 5: Vulnerable environments, 6: Growth & development strategies, 6: Procurement transparency, 6: Financial & debt sustainability, 6: Anti-corruption, 6: Access to information and data, 6: Legal and Regulatory Frameworks, 6: Institutional Framework of infrastructure investment, 6: Transparency of infrastructure investment, 6: Enabling Environment, 6: Policy
The Thames Tideway Tunnel is an interceptor sewer being constructed in central London to control the 39 million tonnes of untreated sewerage that flows in to the Thames River on an annual basis. The sewer tunnel runs 25 kilometres long, intercepting 34 combined sewer outflows (CSOs). The project was successfully bid out in 2016, and is privately financed by the Bazalgette consortium, supported by the UK Government’s fiscal support package, to mitigate the project risks and make the project viable for private financing. The planning of this project is a reflection of the UK’s inter-agency coordination. The Department of Environment, Food & Rural Affairs (DEFRA), responsible for the overall policy on water and sewerage in the UK, worked closely with Thames Water, a private company responsible for sewerage infrastructure in London, to develop a solution for the overflows. While Thames Water undertook the planning, design and tendering of the project, it was also supported by IUK (later IPA) owing to its major project status. The Water Services Regulatory Authority (Ofwat) was the independent economic regulator to determine the charges to be borne by the customers of Thames Water for funding the tunnel construction.
Size: 25km sewage tunnel
The overall solution is made up of:
- upgrades to five sewage treatment works ("STWs") at a cost of £675m largely completed in 2014,
- the 6.9km long Lee Tunnel at a cost of £635m, completed in 2015 and
- the 25km Thames Tideway Tunnel at a cost of £4.2bn.
Parties involved (public and private):
- Infrastructure Provider is the Bazalgette Consortium made up of Allianz, Amber
- Infrastructure, Dalmore Capital and Dutch Infrastructure Fund.
- In addition, there are the following delivery partners: https://www.tideway.london/about-us/our-delivery-partners/
Relevant contractual details (type, length etc.): Separate Company “Infrastructure Provider”- Private Delivery with Contingent Government Support.
Aim(s) of the project: To alleviate the sewage overspill into River Thames.
Relevance to QII
A range of benefits will remain that go beyond and outlive the tunnel construction, including new standards for health, safety and wellbeing in delivering major projects; a rejuvenated river economy and a new public realm for the people of London to enjoy and connect with the River Thames. In delivering these benefits, the project will seek to ensure that the delivery of Thames Tideway Tunnel represents the best long-term value for money.
Highlights: The "super sewer" will prevent millions of tonnes of sewage entering the river each year - with all the ecological and health benefits that will bring.
Expected and realised benefits: https://www.tideway.london/benefits/
The project is subject to the Gateway Reviews and was until 2017 part of the UK Government?s Major Project Portfolio (GMPP) monitoring, in order to provide high level of openness and transparency. Once the project is through construction in 2023 and in service, it will be subject to an internal DEFRA Gateway 5 Review to assess its Benefits Realisation.
Name of Institution
Infrastructure and Projects Authority (IPA)