River Thames, London

Physical and flood context

This case study focuses on a segment of the River Thames catchment situated west from the City of London, which covers approximately 50 Km from Maidenhead (Royal Borough of Windsor and Maidenhead) to Teddington (London Borough of Richmond upon Thames). The area is part of the fluvial Thames (as opposed to the tidal Thames which runs downstream from Teddington) and has two interesting flood management projects that are examined within this study: the Jubilee River (upstream from Datchet) and the River Thames Scheme (downstream from Datchet). The Jubilee River (JR) is an existing and ongoing project since 2002, whereas the River Thames Scheme (RTS) has been formally approved, but remains subject to funding. These schemes emerged under different paradigms ofLondon Skyline flood management in England and therefore provide an interesting opportunity to perform a comparative analysis.

These region suffered major floods on several occasions, chiefly fluvial flooding from the River Thames; for example, in 1947 England suffered one of the worst floods with a 2% annual exceedance probability, resulting in most of the Thames Valley flooding. Another severe flood was in 1968, and more recent significant floods were in 2003 and in January 2014 when most affected areas were downstream from the JR. These two last events are peculiar as they happened after the Jubilee River was opened. Many stakeholders with interests in the area continue to blame the construction of the alleviation channel, arguing that the scheme exacerbated floods downstream from Datchet. Other types of floods in the area are from surface water and sewer flooding, and rising groundwate

 

The Jubilee River

The Maidenhead, Eton and Windsor alleviation canal, later called the Jubilee River (JR) protects 3000 properties at risk of flooding. It was built by the Environment Agency in order to reduce flood risk between Maidenhead and Datchet. While it does not protect communities downstream of the scheme, it operates so that flood levels downstream are not adversely affected. The channel was designed to carry 215 m3/sec, 42% of Thames flood flow during a 1 in 65 year event (slightly bigger than the 1947 floods). Funding for the Jubilee River came primarily from two sources: The Agriculture Ministry’ grant-in-aid and the Local Authority community charge. MAFF’s grant-in-aid was 15% of the total and the rest was raised by the community charge (by Local Authorities through local levies).

thames

 

The River Thames Scheme

The area from Datchet to Teddington is one of the largest and most at risk developed flood plains in England with 21,000 properties and 50,000 people at a 0.5% annual exceedance probability or higher. The river in this area has no formal defences, except for eight weirs, to prevent floods and to maintain navigation depths. A particularity of the scheme is that it comprises both structural (e.g. flood diversion channels) and non-structural measures (e.g. installation of property level products). The Scheme has been approved, however is still subject to funding under the Partnership Funding approach introduced in 2011.

 

Research motivation

A number of interesting aspects of flood risk governance are examined as part of this case study:

  1. Implementation of defences under different paradigms

The RTS and the JR have been on the political agenda since the beginning of the 1980s; however the RTS tried gain approval on several occasions without success. This study investigates the reasons why the construction of the Jubilee River was approved initially in the late 1990s whereas measures for the remaining area were not approved until 2010. Exploring the approval processes and funding of two different schemes along this neighbouring stretch of river permits us to compare and evaluate decision-making processes and the resulting impact of these. Through this, we examine resource allocation and power exercised through different political and economic contexts; for instance, what factors enabled the Jubilee River to score higher than the other areas? Where there powerful groups who were successful in securing their interests? How was this achieved?

  1. Implementation of bridging mechanisms

Through this case study we analyse several bridging mechanisms. This case study investigates newly formalised procedures providing a duty for different organisations to work together to deliver sustainable development. One example is the ‘Duty to Co-operate’, implemented as part of the Localism Act 2011 and relevant for our understanding of the sub-Flood Risk Governance Arrangement for spatial planning; on this aspect, we examine how neighbouring Local Planning Authorities, Lead Local Flood Authorities and other organisations with statutory functions work together to consider the issue of flooding. This involves an investigation to see how and to what extent LPAs and LLFAs are realising this requirement in the preparation of their Strategic Flood Risk Assessments and subsequently how these are implemented into Local Plans. On this front, we examine whether spatial planning is considering flooding better as a result of these newly formalised cooperation requirements or if they are likely to have an influence in the future.

By focusing on the RTS this study also assesses modes of cooperation in this formalised partnership between the Environment Agency, the Local Authorities within the areas (Seven LA’s are involved in the RTS), Defra and Thames Water. The fact that the area affected by the RTS involves two local authorities belonging to the Great London Authority makes this scheme distinctive from other cases.

 

There are a number of specific questions that are addressed in this research and listed below:

  • How will the new Defra Flood and Coastal Resilience Partnership Funding affect the delivery of FRM in the area?
  • To what extent is there evidence for effective partnership working in the River Thames? Are there any barriers to partnership work?
  • What are the tensions and barriers encountered in delivering defence and mitigation strategies? How is this resolved?
  • How has FRM evolved in the River Thames since the design of the Jubilee River? To what extent has the resilience to flooding of this area been enhanced since the opening of the Jubilee River? Are there any differences between the areas in terms of resilience?
  • What are the main differences between the Jubilee River and the River Thames Scheme in terms of flood risk governance arrangements?
  • How effective in practice is spatial planning in considering flood risk and preventing inappropriate development?
  • How do the governance processes relating to spatial planning and flood risk work in practice?

For further details contact Paula Micou at p.micou@mdx.ac.uk