It took flood disaster to finally get action
PUBLISHED: 17:04 12 April 2007 | UPDATED: 13:56 04 May 2010
BY 1947, the subject of how to prevent wide-scale flooding of the Fens had been fiercely debated for many years. Parts of Fenland were five feet below mean sea level and the real problem was not drainage, but the protection of the Fens from flooding cause
BY 1947, the subject of how to prevent wide-scale flooding of the Fens had been fiercely debated for many years. Parts of Fenland were five feet below mean sea level and the real problem was not drainage, but the protection of the Fens from flooding caused by the overtopping of the river embankments during times of high water. Three hundred years after Vermuyden had drained the Fens, the peat was still shrinking.
The obvious solution was to make the flood banks high and strong enough to contain the floods. This could not be achieved, however, because beneath the peat, on the Fenland floor, is a lining of soft, silty "buttery clay". When clay was added to the flood banks the consolidation of the underlying peat and soft clay led to a rapid loss of height.
This meant that it was impossible to continually heighten the banks; the added weight could even cause a slippage of the entire bank, thus defeating the objective. From the late 19th Century, the emphasis of flood relief in the area was focused on the outfall at the Wash, schemes highlighted the theory that water was not "getting away" quickly enough.
What these proposals failed to recognise was that the main Bedford branch of the River Great Ouse met the flow of the Eastern catchment area which drained parts of Norfolk, Suffolk and Cambridgeshire. While the Ely branch was non-tidal from Denver sluice, the tide affected the entire length of the New Bedford River. At peak times flood water could not flow quickly enough through the system so the banks were overtopped.
The preoccupation with the outfall meant little advance was made in the first half of the 20th Century and the area suffered from disastrous flooding in 1912, 1936, 1937 and of course 1947. Part of the problem was that there was no single authority or organisation at the time to take responsibility for such a large scheme and raise the necessary funds.
In 1914, the Land Drainage Act was passed under which the Lower Ouse Drainage Board was set up. The initial proposals to the board advocated training walls in the Wash; this was rejected at an inquiry in 1918. Another idea was a barrage across the river at King's Lynn, effectively locking the river from tidal waters; flood water could be stored in the tidal section of the river until safe to discharge. Neither was adopted.
Finally The Land Drainage Act of 1930 established The Great Ouse Catchment Board. With wider authority it inherited a sadly neglected river system, particularly the dangerous condition of the South Level banks. Over the next few years a series of recommendations were put forward to the board, but these had conflicting views on the best action to take. The floods of 1936 and 1937 prompted action. The board commissioned a report from Sir Alexander Gibb & Partners who proposed a large pumping station at Denver with a discharge channel to hold flood water when the tidal river was closed at the outfall.
Still unsure of what action to take, The River Great Ouse Catchment Board called in Sir Murdoch MacDonald & Partners. Their report of July 1940 gave alternative solutions. It proposed a relief channel from Denver St Germans and a cut-off channel, running from Denver around the edge of the Fens to Grantchester. This was later revised in December 1940; retaining the relief channel, installing a pumping station at Earith and work on the banks.
The plan was adopted, but due to the war could not be implemented. The rest as they say 'is history'. Without the scheme in place came the record flood of 1947 which cost the country some £12m.. The original scheme had been considered too big, now it was thought too small. Those who had prevaricated about the cost were now only too happy for the Flood Protection Scheme to be carried out without further delay.