Horncastle Floods Earthcache
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The River Waring is a small river in Lincolnshire, England, and a tributary of the River Bain. The Waring rises in the parish of Belchford and runs through Belchford village, passing between the villages of Fulletby, West Ashby and Low Toynton before arriving at Horncastle, where it divides Horncastle market place from the part of the town known as Cagthorpe.
HISTORY OF RIVER FLOODING IN HORNCASTLE
In a shallow valley at the confluence of two meandering rivers, the Bain and Waring, and receiving the faster flowing Thunker or Scrafield Beck, it is not surprising that Horncastle has been subject to periodic flooding. The Ings along the Bain were under permanent pasture as a natural flood reservoir, and in the 16th century rents on some lands in the manor were waived due to 'total waste by water'. The effect of the canal and the dam were to slow down the run-off. In January 1854 there had been heavy snow and the Upper Waring basin was frozen, but a sudden thaw piled ice against the town bridge and adjoining premises were flooded. Heavy rain in mid-July1855 removed 'vast quantities of noxious matter' from the south basin, ybut two thunderstorms on the 25th and 27th flooded streets and the Bain valley above and below the town. In October the same year further heavy rain caused both the Bain and Waring to overflow
The Bain flooded again in July 1866, and in November heavy rain caused a rapid rise of the Bain, Waring and Thunker, flooding lower parts of the town 'in consequence of the neglected state of the watercourses'. Both rivers flooded in 1887, l880 and particularly badly in February 1897 due to a combination of thaw and rain. More serious flooding, with damage to buildings, occurred on 29 May 1920. The storm passed over Horncastle towards the Wolds in the afternoon and produced such heavy rain (6.3 ins) that the streets were awash, but the flood waters did not arrive until six o'clock.
The Waring overflowed first and within half an hour, East Street, part of Spilsby Road, part of the Bull Ring and South Street, and Willow Row and Wharf Road were under water. Over the next two hours the main volume of water came down the Bain from the Wolds, with flooding even into the Market Place and joining with rising water from the Waring in Church Street. Efforts had been made in 1915 to get the doors of the flood gates into working order and to remove the impediment of the derelict gates on the first lock of the canal (outside UDC control), but with little success. In 1920 it was felt proper attention to these, and the width of the Bridge Street arch, would reduce the possibility of future flooding. But 40 years later it happened again. On 7 October 1960 rain began to fall about 10.30 am. By 11 am it was torrential, and continued with little abatement until 5.00- 5.30 pm.
The storm cloud towered well above 40,000 ft over Horncastle. A total of 7.24 ins of rain in six hours fell on the town, and at Revesby Reservoir on the Haltham Beck 6.41 ins fell in three hours. At Hemingby, three miles above Horncastle, the Bain was running only half full, but the Waring and the Thunker Beck together were discharging four times as much water. And the flow in the little Haltham Beck four miles south of Horncastle was contributing more water than the normal discharge of the River Thames at Teddington.
Although the old Canal had been cleaned and dredged as an auxiliary channel for the Bain water; silting was still evident on the canalised Waring, where the bed was sometimes within three feet of the level of the roadway. The Waring, the Bain and the old canal all proved inadequate to carry away the great volume of water. At noon the Waring began to overflow and, within two hours, the great quantity of water brought down by the Waring and Thunker, and by roads sloping to the river, was being discharged into the town.
Many premises were flooded up to a depth of six feet, even eight feet in a few areas. At the time of maximum flow, caravans, timber from Prestwood's yard, and a car and a van were swept down the Waring; the debris formed temporary dams which increased the depth of flood water and played a part in carrying away two footbridges
Flooding on the Bain above its confluence with the Waring was due to ponding back, with discharge further impeded by the remains of the staunch doors. Below Horncastle the valley was extensively flooded all the way to the confluence with the Witham at Dogdyke. By 8 o'clock that evening most of the streets of Horncastle were clear of water and by the next morning the Waring was well below bank-full. The most recent flood occurred in 2007
CAUSES OF RIVER FLOODING IN HORNCASTLE
A flood occurs when a river bursts its banks and the water spills onto the floodplain. Flooding tends to be caused by heavy rain: the faster the rainwater reaches the river channel, the more likely it is to flood. The nature of the landscape around a river will influence how quickly rainwater reaches the channel. The following factors may encourage flooding:
A) A steep-sided channel - a river channel surrounded by steep slopes causes fast surface run-off; in the Wolds
B) A lack of vegetation or woodland - trees and plants intercept precipitation due to intensive agriculture in the region
C) There is little vegetation in the drainage basin then surface run-off will be high.
D) A period of prolonged and heavy rain causing the soil and bedrock to become saturated
E) A drainage basin in an urban area - these consist largely of impermeable concrete, which encourages overland flow. Drains and sewers take water quickly and directly to the river channel. Houses with sloping roofs further increase the amount of run-off.
EVIDENCE OF FLOODING IN HORNCASTLE
Adjacent to the GZ is a brass plaque marking the height of the 1960 flood. This can be found on the wall of the estate agents.
TO CLAIM THIS CACHE
Answer the following questions and email or message them to the CO
1) The River Waring has been significantly altered by human activity, without this it would be in its mature or lower stage. Describe what you would expect in terms of channel shape, discharge, size and depth if it hadn't been turned into a culvert.
2) "Levees" are elongated ridges formed along the floodplain. Describe and explain how these are formed by natural processes. What evidence is there of man made flood defences in the vicinity of the river?
3) The storm hydrograph of both the 1960 and 2007 floods shows a short "lag time". Explain what this is and what effect the current land use around the river might have led to it happening.
4) Using the plaque, estimate how much higher the river reached than its current level and how this might affect the infrastructure of the town.
Additional Hints
(Decrypt)
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