thumb|right|300px|The Jubilee River at Slough Weir

The Jubilee River is an artificial flood-relief channel in southern England. It is long and is on average wide. It was constructed in the late 1990s and early 2000s to take overflow from the River Thames and so alleviate flooding to areas in and around the towns of Maidenhead, Windsor, and Eton in the counties of Berkshire and Buckinghamshire. It achieves this by taking water from the left (at this point eastern) bank of the Thames upstream of Boulter's Lock near Maidenhead and returning it via the north bank downstream of Eton. Although successful in its stated aims, residents of villages downstream, such as Wraysbury, claim it has increased flooding in those locations.

Construction

Parts of the towns of Windsor, Eton and Maidenhead are prone to flooding, because they are built on the flood plain of the River Thames. The concept of a parallel channel which could take water from the Thames above Maidenhead and return it below Windsor was conceived in the 1980s, and became known as the Maidenhead, Windsor and Eton Flood Alleviation Scheme. When the ten regional water authorities were privatised, as a result of the Water Act 1989, responsibility for rivers passed to the National Rivers Authority, which soon afterwards submitted plans for a channel which would be wide and long. In October 1992, a planning enquiry was held to consider the proposals. During that enquiry, P. Ackers, one of the assessors, expressed grave doubts about the hydraulic modelling that had been used to justify the scheme, suggesting that it was too optimistic.

The scheme did not receive government approval until 1995; around the same time, there was further reorganisation of the water industry, with the Environment Agency replacing the National Rivers Authority. Although Ackers' concerns had not been addressed, it commissioned the design and construction of the scheme as originally conceived, at a cost of £110 million. Throughout the planning process, from initial feasibility studies to delivery of the project, Lewin, Fryer and Partners were the consulting engineers. Principal works were the creation of the channel, various flow control mechanisms and bridges for road, rail and foot traffic.

left|thumb|Dorney Bridge

One of the challenges was the Dorney Bridge, built to take the channel beneath the Great Western Main Line. The 19th-century Brunel-designed railway embankment continued in use, carrying passenger and goods trains between London and destinations including South Wales, Cornwall and Bristol throughout construction. The high embankment was stabilised along 30m of its length by freezing over a period of three months, using 175 brine tubes cooled to . A tunnel was excavated through the frozen ground to just wider than the two long preformed concrete box sections, which were jacked through as the excavation proceeded. This created a wide by high concrete culvert which can be seen from the Bath Road Bridge. There was considerable erosion at the Taplow Sluice, due to the lack of a stilling basin; embankments at Marsh Lane were badly damaged; the weir at Manor Farm was bent in the middle; the protection on the downstream face of Slough weir was swept away; and in Datchet, the Myrke embankment nearly collapsed. An independent assessment by the engineering consultancy WS Atkins identified that the actual capacity of the channel was around two-thirds of its design capacity, and factors affecting this were the banks being too low, the use of inappropriate materials, and failure to follow standard design criteria. A programme of repairs and upgrades to rectify the problems began, at a cost of £3.5 million, and took until 2006 to complete. The Environment Agency sued their lead design consultants for recovery of the remedial costs, and were refunded £2.75 million in an out-of-court settlement, after they admitted that the design and construction were sub-standard.

Name

The name used during planning was the "Maidenhead, Windsor and Eton Flood Alleviation Scheme" (MWEFAS). The choice of a name for the river was put to the local population in a poll. The result was a strong preference for 'Jubilee', as it was being completed in Queen Elizabeth's Golden Jubilee year of 2002 and one of the Queen's main residences was at Windsor Castle, in one of the three towns being protected by the scheme.

In use

The watercourse was designed to look like a natural river; its banks have artificially constructed wildlife habitats intended to replace those lost from the banks of the Thames during urban expansion in the 19th and 20th centuries. During construction of reed beds and of wet woodland were laid down and about 250,000 trees were planted.

See also

  • Tributaries of the River Thames
  • Meander cutoff
  • List of rivers in England
  • Waterways in the United Kingdom
  • 1947 Thames flood

References

Bibliography

  • Discussions and articles relating to the Jubilee River
  • Information on the Jubilee River and the floods of 2003
  • Information about the habitat of the Jubilee River
  • Information on the National Cycle Network and the Jubilee River