The slope of rivers running towards Lynmouth and the high rainfall in their catchment determines high possibility of flooding there and the likelihood of severe erosion. The deep, incised valleys and smooth contours provided little storage for excess waters. The poor maintenance of the river had left previous flood debris and trees in the flood's passage. Further restrictions were placed upon the river with the encroachment of properties upon the river banks. The saturated soils could retain little of the precipitation that had fallen on Exmoor over the previous days. The water table was already high and all the water had to travel into the river system.
The presence of low pressure convinced weather men that this was an explainable scenario, although rather unusual. Thunderstorms had played a major part of the British weather throughout the country, where observation had been remarked at the rarity of such events. Further remarks used such terms as 'unorthodox', which, when later combined with Whitehall officials' admittance that rain making experiments had sometime been conducted over Lynmouth, fuelled the belief of government responsibility. Official declassified files were later obtained by The Sunday Times and provided the first evidence that during the height of the Cold War the MoD was trying to develop techniques to flood enemy trenches, paralyse forces and bog down tanks in the event of a Soviet invasion. This experiments involved the dispersal of silver iodide or dry ice particles from small aircraft into clouds to induce rain in a technique called cloud-seeding (Brennan, 1997). The records show that ministers authorised rainmaking experiments across Britain from 1949 to 1957. However, a connection with the disaster has not been demonstrated and there is no evidence of success of or co-incidence of experiments over Lynmouth. The only experiments taking place anywhere near the time of the flood were in East Anglia and the flood was caused by a depression moving eastward from the Atlantic and drawing in moist air from France and Wales.
The ascending warm moist air up and over Exmoor played another additional key role in the flood explanation. For the peaking of both rivers concurrently is rare. The usual time lag between the rivers means that the West Lyn peaks prior to the East, unless there are two sources of rainfall. The moisture release from the local uprise of air over Exmoor produced the second source, which was sufficient to bolster the East Lyn and advance it by adequate time to peak at the same time as the West Lyn.
Lynmouth was prone to floods and was ready for a once in two centuries flood such as the 1952 flood. By examining the physical environment the inevitability of such an occurrence was very real. All that Lynmouth was waiting for was the rains, and, like so many communities that live in potential risk areas, this was only a matter of time.
The measures undertaken to secure the safety of the village have continued to work. The major undertakings of channel clearance and widening have ensured an adequate area for the water to travel through unhindered. Reconstruction of bridges and the removal of bank side houses have further warranted against the damming and blocking of the rivers. Early warning systems have been put into place to alert those who may be in danger. To date several warnings have been given when the river level has climbed. Localised flooding has occurred around the Barbrook area but nothing in resemblance to that of 1952. Some say that Lynmouth's charm has been lost but it has emerged in a resurrected and changed form, attractive, picturesque and, hopefully, safe.
WHY DID THE FLOOD HAPPEN?
Exceptionally heavy rain occurred at a time when the ground was already saturated.
Drainage and steepness of the valleys contributed to rapid run-off. The rivers are ‘spate’ rivers where floods are commonplace.
The Lyn Rivers include a large area of high, wet moorland in their catchments and the rivers meet at Lynmouth, where all of the water from this large area is concentrated.
The rivers at Lynmouth have been ‘rejuvenated’, resulting in narrow valleys and confined channels unusual for rivers at the end of their courses.
WHY WAS THERE SO MUCH DAMAGE?
There had been much building on the flood plains of rivers.
Development had diverted rivers from their flood courses and confined them in unnaturally narrow channels.
Exmoor’s north-flowing rivers descend to the sea very steeply, giving them much speed and power to erode.
Obstacles to flooding had not been cleared.
WHY WAS THERE SO MUCH LOSS OF LIFE?
The flood occurred in complete darkness and it was difficult to assess the amount of danger or safe means of escape.
It was the peak of the holiday season and the population was swelled with tourists.
Local people were used to flooding and did not evacuate their homes because they underestimated the danger from this exceptional flood.
Houses and holiday accommodation were built close to the rivers.
Some of the dead had been staying in tents, caravans or insubstantial buildings that had not been able to withstand the flooding.
WHAT HAS BEEN DONE TO ENSURE THAT THE DISASTER IS NOT REPEATED?
Floods of this magnitude have occurred roughly once every two centuries and are likely to occur again. They cannot be prevented, only contained.
A flood warning system has been installed.
Building on flood plains has been restricted. Buildings have been removed to ensure that flood waters are no longer confined.
River channels and bridges over them have been widened to accommodate a flood of similar proportions. A larger flood would still cause damage but within the settlement of Lynmouth the river channel has been designed so that flood water would mostly spill over the Manor Green on the eastern side of the river, away from the main settlement.