Greenwich Tourist Map

A Forty-Year Horizon to 2052

Here is a list of what we might hope to achieve on the London River

•An abundant and constant supply of fresh clean water. This will involve close monitoring of the aquifers and tributaries of the Thames Basin, some new reservoirs and a radical overhaul of the distribution and sewage system resulting in zero spillage and a much cleaner River Thames.

•100% protection from freak tidal flooding, particularly the Central London area and new population concentrations such as Canary Wharf, Woolwich, Thamesmead, Tilbury, Gravesend and Southend. This will involve the completion of a much more secure new tidal barrage or barrier and comprehensive protection along the riverbank upriver and downriver.

•Intensive development behind these new defences, a new industrial and manufacturing hub dependent on very close links with Continental Europe and, hopefully, a large new international hub airport and container port located in the Estuary area. This should be just one part of a growth and investment strategy for the entire country.

There are many dangers and risks ahead, but possibly the greatest is ending up doing nothing or next-to-nothing.

Let us focus, for example, on the risk of London sustaining massive damage from another freak tidal flood. The incidence of such tidal surges is roughly every 25 years over

the last four hundred years, but many earlier floods were recorded. In 1242 in the Great Hall of Westminster “men did row with wherries in the midst of the Hall and took their horses because the water ran overall” while at Woolwich a great number of inhabitants were drowned and “at Lamberhithe, the Thames drowned houses and fields over a space of six miles”. More recently, exceptional tides causing serious flooding occurred in 1791, 1834, 1852, 1874, 1875, 1881, 1928, 1953 and again, thanks to the new defences and higher river walls, without serious flooding, in 1978.

Today, we know that the danger starts on the Eastern Seaboard of USA and Canada, where the warm water of the Gulf Stream flows north to meet the icy Labrador current. In certain westerly conditions this results quite frequently in a wave typically about one foot in height and up to several hundred miles in length being generated that passes round the top of Scotland, where it can be easily measured, and into the North Sea. Normally it dissipates here, but occasionally if the weather changes, this water is driven south by strong north or north-easterly winds towards the Netherlands and our East Coast. Here the water-level rises much higher because of the funnel effect of the North Sea and the same phenomenon occurs on a much more dramatic scale at the entrance to the London River after the rogue surge-tide is compressed into a width of about half-a-mile. As Professor Hermann Bondi concluded half a century ago, there is no good reason to assume that this event will not happen again and over the last half-century, there is firm evidence that the wave-height and recorded tidal height could be increasing.

When the Barrier was formally opened in 1984, it was expected that full closure would be necessary for training purposes three times a year but not at all for other reasons. Between 1983 and 2010, however, the Barrier has been raised 119 times, of which 76 were to protect against tidal flooding and 43 to alleviate fluvial flooding after heavy rain in the Upper Thames Valley.

The flooding of Central London would inflict immense damage on the UK economy and that is why its prevention must remain top of the policy agenda.