LANCASHIRE: A CHRONOLOGY OF FLASH FLOODING Introduction The past focus on the history of flooding has been mainly with respect to flooding from the overflow of rivers and with respect to the peak level that these floods have achieved. The Chronology of British Hydrological Events provides a reasonably comprehensive record of such events throughout Great Britain. Over the last 60 years the river gauging network provides a detailed record of the occurrence of river flows and peak levels and flows are summaried in HiflowsUK. However there has been recent recognition that much flooding of property occurs from surface water flooding, often far from rivers. Locally intense rainfall causes severe flooding of property and land as water concentrates and finds pathways along roads and depressions in the landscape. In addition, intense rainfall can also cause rapid rise in level and discharge in rivers causing a danger to the public even though the associated peak level is not critical. In extreme cases rapid rise in river level may be manifested as a ‘wall of water’ with near instantaneous rise in level of a metre or more. Such events are usually convective and may be accompanied by destructive hail or cause severe erosion of hillsides and agricultural land. There have been no previous compilations of historical records of such ‘flash floods’or even of more recent occurrences. It is therefore difficult to judge whether a recent event is unusual or even unique in terms of the level reached at a particular location or more broadly of regional severity. This chronology of flash floods is provided in order to enable comparisons to be made between recent and historical floods, to judge rarity and from a practical point of view to assess the adequacy of urban drainage networks. In the following chronology for South Yorkshire events are listed by date and by the source of the information. Where meteorological information is available especially rainfall depths over daily or shorter durations, this is listed in the second column. The description of the event then indicates the location and extent of the flooding, including levels or depths on roads and buildings which may still be identifiable. The occurrence of associated hail and especially of large hail has been included where available. Information of human interest but lacks indication of the magnitude of the flood has generally been omitted. The earliest record for South Yorkshire is from 1594 and information is intermittent or description is sparse until 1800 after which the listing of occurrences is considered comprehensive and by 1850 multiple sources provide detailed accounts. This chronology is part of a set of regional compilations of flash floods for Northern England and for Southwest England and includes the following separate chronologies. Yorkshire Rye and North York Moors Yorkshire Swale Northeast England River Eden Derwent and Cumbrian Coast South Yorkshire Kent and Leven etc Lancashire Including neighbouring counties draining to the Mersey estuary Southwest England – Cornwall and Devon In addition, a more selective compilation of extreme events has been created for the remainder of the British Isles. This is not intended to be comprehensive but picks out events which have been noted by the compiler. Meteorological information As a first step in identifying potential dates of flash flooding the publication British Rainfall 1863 – 1968 (Symons British Rainfall from 1863 to 1900) was inspected to ascertain the meteorological conditions associated with flooding – thaw, thaw with rain, frontal rainfall, convectional storms etc. Of particular interest were the records provided of rainfall amounts of specified short duration. Early records of short period intensity were usually derived by observation of the amount and start and end time of intense rainfall. Later records were extracted from recording rainfall gauges, either Dines Siphon or Tilting Bucket records. Very high daily totals were also noted. Those relevant to south Yorkshire were extracted. The Climatological Observers Link (COL) from 1970 to the present has been used to fill out the later period for intense rainfall although the number of stations is small especially in the early years during the 1970s but is supplemented by observer’s descriptions of events. Philip Eden’s Great British Weather Disasters provides a chronology of severe events from 1901 to 2008, including strom winds, snow and thaw, and intense or prolonged rainfall. Sources of flood Information Descriptive information is contained in newspaper reports, diaries and further back in time, from Quarter Sessions bridge accounts and ecclesiastical records. The main source for this study has been from newspaper accounts. Early Newspaper Source The Lexis British Newspaper Archive has digitised large continuous runs of newspapers which have been accessed on the web. A search facility identifies all occurrences of given words or combinations of words, by newspaper, by county, by region and by date. The phrase ‘flash flood’ is a 20th century description, so alternative words were required to ensure that all potential flash flood events were identified, without producing an excessive number of irrelevant events. The words ‘flood’ and thunder’ were adopted. The search facility includes within these words variants such as ‘flooding’ and ‘thundering’. Up to 50% of the occurrences identified were of descriptions of ‘floods of tears’ or ‘thundering speeches by politicians’ but is likely to have produced a comprehensive set of flash flood events. All relevant information was extracted from the identified descriptions, such as location, associated meteorological conditions, the occurrence of hail, magnitude and extent of flooding, depth in buildings, fatalities from drowning or lightning, animal losses, bridges and buildings damaged by flood or lightning, severe channel erosion and descriptions of rapid rate of rise in level. Except where events were of very unusual magnitude, winter floods produced by long duration rainfall or snowmelt events were excluded. Only information which could be used to define the magnitude or severity of a historical flood in relation to a recent gauged flood has been included. The following is a list of the newspapers that have been accessed on the British Newspaper Archive, with the dates currently available. It is noted that although some papers continue publication to the present, for copyright reasons the current archive extends only to 1900 or to 1950. Hence records are most comprehensive for the period from 1850 to 1900, but sufficient newspapers are archived up to 1950 to provide comprehensive data up to that date except for the years of World War II when press restrictions were placed on natural incidents such as thunderstorms and floods. The earliest concurrent newspaper record is for 1753 from the Manchester Mercury. However occasional reports and descriptions of earlier historic floods are sometimes made, for example in the Burnley Express in August 1905 referring to floods in 1580 and 1666. A few early records have also been extracted from The Gentleman’s Magazine (Hardcopy in the British Library) Newspaper Place of Publication Available dates Manchester Courier Manchester 1825-1916 Liverpool Mercury Liverpool 1812-1899 Lancaster Gazette Lancaster 1801-1893 Lancashire Evening Post Preston 1886-1947 Manchester times Manchester 1829-1900 Ashton Weekly Reporter Ashton under Lyne 1855-1871 Blackburn Standard Blackburn 1836-1900 Bolton Chronicle Bolton 1835-1871 Burnley Advertiser Burnley 1855-1877 Burnley Express Burnley 1878-1953 Burnley Gazette Burnley 1863-1914 Burnley News Burnley 1913-1932 Bury times Bury 1855-1869 Leigh Chronicle Leigh 1856-1870 Liverpool Daily Post Liverpool 1855-1871 Liverpool Mail Liverpool 1836-1873 Manchester Evening News Manchester 1870-71 1914-17 Manchester Mercury Manchester 1753-1830 Preston Chronicle Preston 1831-1893 Rochdale Observer Rochdale 1856-1870 Cheshire Observer Chester 1854-1916 Chester Chronicle Chester 1775-1870 1914-17 Newspapers after 1950 Apart from the British Newspaper Archive, individual national newspapers have online digital archives. The following have been inspected for occurrence of ‘flood’ and ‘thunder’ from 1950 onward – The Times, Daily Mail and the Guardian (originally the Manchester Guardian but becoming a national newspaper in 1959). These sources could be expected to report events of national interest but could well have missed local events even if severe. The Manchester Library provided access to the online source of NewsBank Newspapers UK and the World. For Northwest England this provided access to 34 local and regional newspapers. The earliest of these commences in 1995 but most of the newspapers have much shorter records. Only 4 records start before 2000 and a further 3 before 2004; the remainder mainly commence in 2007 and most continue to the present. Coverage is such that in the period with multiple sources, similar material is provided by each. It is likely that information on flooding from intense rainfall is comprehensive from 1995. Ther remained a period from 1950 to 1995 during which local sources were not available online and it was therefore it was considered necessary to access local newspapers in libraries or record offices. The principal source here was the Lancashire Evening Post inspected on hard copy and microfilm at the British Library at St Pancras (so far 1950, 1953 to 68 and 86 to 91 – to be completed). Flood Chronology Date and Rainfall Description sources Aug 1580 Thunderstorm Pendle Hill has burst its bonds and spread dismay and destruction far and wide. The great rents known as Sabden and Burnley Gazette Ogden Cloughs were by tradition created in such cataclysms. Those of Burst Clough and Braggarts Hole were with 15 Aug 1905 certainty to have been thus caused. Of these eruptions the most furious occurred in August 1580. Previous weather had been hot and sultry. The rain was such as had never been before experienced. In several places on the summit of the hill there were spouting vast columns of water earth sand and stones with a loud hissing noise.