Outer Trial Bank

History

In 1972, the British government undertook a study to assess the feasibility of building a tidal barrage across half of the Wash. The idea was to capture the freshwater from the River Witham, River Welland, River Nene and Great Ouse, the four main rivers which flow into the Wash, in order to build a freshwater reservoir. The study also intended to establish potential improvements to the navigation of sea locks, provide recreational facilities and develop an area of land for a power station.

Construction of the banks

As part of the test, the approval to build an artificial island 2 mi off the Lincolnshire coast was given in November 1974. Building work began in February 1975. The bank (known locally as "the doughnut" due to its biconcave shape) was constructed of a sand fill protected by limestone rubble. Measuring 250 m in diameter, the island contained a small reservoir measuring 1 ha in the centre.

A smaller and cruder trial bank is connected by a causeway on Terrington Marsh, Norfolk (). It was constructed prior to the larger offshore version.

Conclusions

The study, which was published in 1976 as "The Wash storage scheme", found that the trial alone proved financially unfeasible (costing £3 million), and that the freshwater was too close to the tidal estuary to ensure low salinity and minimal silt levels. The trial was soon abandoned and the plans for the scheme permanently shelved.

Present use

References

References

1. Richards, Matt. (8 October 2008). "Investigation of Wash Island". BBC.
2. "The Past". The Wash Estuary Strategy Group.
3. (1975). "Wash Water storage scheme". British National Committee on Large Dams.
4. (1976). "The Wash storage scheme: report on the feasibility study". [[The National Archives (United Kingdom).
5. (15 October 2008). "Abandoned: What's in the Wash?". BBC Lincolnshire.