Flood risk at Lauder and Earlston: the historical record Dr Duncan W Reed 17 April 2018 A pro bono report Context The report explores the history of flooding from the Leader Water and Turfford Burn. If something more useful than risk assessment is to emerge from the Earlston Flood Study, it will be important to understand why redevelopment in Earlston has never quite grasped the limitations imposed by its setting alongside the Burn, in spite of drainage improvements undertaken in the late 1890s and again in the late 1960s. Perhaps because of the recurrent flooding problem with the Turfford Burn, flood risk at Earlston from the Leader itself has not always gained the attention it deserves. SEPA’s flood- risk map indicates that a large Leader flood could have high impact there. A few residents and businesses are exposed to flood risk from both the Leader and the Burn. However, the large majority are principally vulnerable to one rather than the other. This will understandably influence their expectation of actions to be prioritised following the Earlston Flood Study. This split could make for a rocky road if the two problems continue to be kept under one umbrella. The situation at Lauder is helped by special factors that have in the main kept development away from the Leader Water. There are relatively few properties currently mapped as at risk from the Leader Water. However, it is demonstrated that the flood-risk modelling and mapping work has not taken adequate account of the historical flood record. A surprising planned development at Thirlestane makes Leader flood-risk topical from the Harry Burn to Earlston, and possibly beyond. A summary of principal conclusions is provided. But the essence of historical flood review lies in the detail. ii Contents i Context ii Contents iii 1 Introduction 1 1.1 Notations 1 1.2 Some formal references to historical floods 1 1.2.1 Tweed Catchment Management Plan 1 1.2.2 Tweed Flood Risk Management Strategy 1 1.3 Critique 2 1.3.1 Why the neglect of historical flood idea? 2 1.3.2 An irony 5 1.3.3 Recap 6 1.4 Planning creep 6 1.4.1 The phenomenon 6 1.4.2 Hereford City 7 1.5 Problems with the Turfford Burn 7 1.5.1 What will happen next? 8 2 Introduction to the flood chronology 9 2.1 Sources and methods 9 2.1.1 Chronology of British Hydrological Events (CBHE) 9 2.1.2 British Rainfall yearbooks 10 2.1.3 Local newspapers 10 2.1.4 Internet searching 11 2.1.5 Books 11 2.1.6 A source that is effectively missing 12 2.1.7 Social media 13 2.1.8 The 1970 to 1995 gap 13 2.2 Introduction to existing flood chronologies 13 2.2.1 McEwen (1985, 1987 and 1990) 13 2.2.2 Reed (2002b) 13 2.2.3 JBA (2009) 14 2.2.4 SEPA (2014b) 15 2.2.5 SEPA (2017) 16 2.2.6 ECC (2017) 16 2.3 Period covered by the review 16 2.4 Event classification 16 2.5 Completeness of historical flood series 17 2.6 Historical prudence 18 2.7 Tree-planting 18 3 The 1818 to 1966 flood chronology 20 9 Feb 1831 LL? EE? KKK 20 11 Jun 1835 LL? E? 21 15 Sep 1839 L? E? KK 22 6 Oct 1841 24 30 Jul 1846 L? E? TT? K 25 8 Aug 1846 27 iii 29 Sep 1846 LLL EEE TT? KK 28 14 Jun 1859 30 12 Jun 1860 E? 30 23 Oct 1864 L EE 31 22 Jul 1867 TT 32 20 Aug 1877 K 33 28 May 1878 33 5 Mar 1879 34 9 Jun 1879 34 14 Jul 1879 34 10 Mar 1881 LL EE KKK 35 22 Sep 1881 L E T 37 12 Aug 1884 38 12 Aug 1890 TTT 39 21 Sep 1891 LLL EE T? KK 41 5 Aug 1895 TTT 45 11 Nov 1895 E T 47 17 Oct 1898 47 12 Jul 1899 E? (Pluvial) 48 24 Feb 1900 48 3 Jul 1900 T 49 10 Aug 1901 LL (Pluvial) 49 30 Dec 1901 T K 50 9 Feb 1903 TT 52 22 Jul 1904 E (Pluvial) 54 25 Mar 1905 54 19 Oct 1906 55 8 Jan 1908 T 55 25 Mar 1908 T 55 ? Sep 1909 LL?? 56 29 Aug 1910 L E? K? 56 4 Aug 1912 58 18 Jun 1914 L 58 6 Dec 1915 T 60 18 Aug 1920 K 61 24 Aug 1925 62 27 Jul 1927 L E 62 22 Sep 1927 LL EE TT KK 64 5 Jul 1929 EE (pluvial) T 67 ≈26 Aug 1930 L? 68 17 Aug 1931 LL? E? T? K 68 10 Nov 1934 E? 70 24 Dec 1937 L? E T? K 70 2 Jun 1938 L E 72 13 Nov 1938 KK 72 17 Jul 1940 L? E? T? K? 74 Mid-Jan 1948 E? T 74 12 Aug 1948 LLL EEE TT? KKK 75 iv 25 Oct 1949 79 28 Aug 1956 LL EE TT KK 80 4 Noted floods since 1 October 1966 83 31 Oct 1977 L (pluvial) 83 3 Jan 1982 L E KK 83 3 Nov 1984 LL? EE 84 6 Oct 1990 EE? 84 1 Apr 1992 85 3 Nov 1998 85 8 Nov 2000 85 22 Oct 2002 EE? T? KK 85 22 Jan 2003 86 ? Oct 2003 86 6 Aug 2008 87 7 Sep 2008 L? 87 23 Aug 2009 88 4 Sep 2009 89 5 Apr 2010 89 25 Sep 2012 L? 89 12 Oct 2012 T 90 26 Dec 2015 91 22 Nov 2016 91 5 Gauged flood data 93 5.1 Comparison of flood data for New Mills and Earlston 93 5.2 Period from 1 October 1966 to 31 July 2001 95 6 Summaries of the flood chronologies 97 6.1 The Leader Water 97 6.2 The Turfford Burn 98 6.3 Targets 98 7 Comparison with other flood chronologies 99 7.1 McEwen (1985, 1990) 99 7.1.1 Tweed 99 7.1.2 Leader 100 7.1.3 Further discussion 101 7.2 Reed (2002b) 101 7.3 JBA (2009) 102 7.4 SEPA (2014b) 103 7.5 SEPA (2017) 104 7.6 Macdonald and Sangster (2017) 104 7.7 ECC (2017) 105 8 Flood risk management in the Leader 107 8.1 Land-use change 107 8.2 Climate change 107 8.3 Geomorphology 108 8.4 Scope for flood risk reduction 109 8.4.1 Past flood management on the Leader Water 109 8.4.2 Past flood management on the Turfford Burn 110 v 8.4.3 Future flood management on the Turfford Burn 111 8.4.4 Future flood management on the Leader Water 113 8.4.5 Summary 113 9 The SEPA flood-risk map 114 9.1 Brief overview 114 9.2 Testing the flood-risk map against the historical record 114 10 Final remarks and caveats 115 10.1 Principal conclusions 115 10.2 Caveats 116 11 Acknowledgements 116 12 References 117 Appendices 121 Historical floods in preceding 50 years 121 History of Earlston water supply – from Berwickshire News 124 Figures Figure 3.1 1909 Plan of Wiselawmill and Farmfoot 56 Figure 4.1 7 Sep 2008 flood, close to Harry Burn confluence with Leader (NT529486) 87 Figure 4.2 The Leader Water at Craigsford Bridge: (a) An Autumn 2012 flood 90 Figure 5.1 Distribution of daily maximum water-levels recorded at New Mills 93 Figure 5.2 Daily mean water-levels at New Mills and Earlston 94 Figure 5.3 Association of daily mean water-level at Earlston to that at New Mills 94 Figure 6.1 Summary of flood chronology: Leader at Lauder 97 Figure 6.2 Summary of flood chronology: Leader at Earlston (E) 97 Figure 6.3 Summary of flood chronology: Turfford Burn (T) 98 Figure 8.1 Cleekhimin Burn and road bridge, 29 April 2010 109 Figure 8.2 17 August 1931 flood, Leader near Oxton (Ref. SBA/32/5) 109 Boxes Box 7.1 Tweed at Kelso chronology from McEwen (1990) 99 Box 7.2 Leader chronology from McEwen (1990) 100 Tables Table 4.1 Eight largest floods, Leader at Earlston, 1966-2016 83 Table 4.2 Extract from British Rainfall 1990 85 Table 5.1 Noted floods in common period of record between New Mills and Earlston 95 Table 5.2 Noted floods between 1 October 1966 and 31 July 2001 95 Table 7.1 Notable floods in the Water of Leith – from Reed (2002b) 102 Table 7.2 Noted floods at Earlston from ECC (2017) 106 vi 1 Introduction 1.1 Notations Particular sections of the report include extensive quotes from newspapers and other publications. Quotation marks are often omitted, although indenting is sometimes used to reinforce that material is verbatim. In general, the source document is stated immediately ahead of the quotation. The ellipse (…) indicates that text has been omitted to aid readability. In quotations, text appearing within square brackets is always added commentary. This is typically used to clarify what the quotation is referring to. The Turfford Burn is widely misspelt Trufford Burn in historical reports, and passes here without further comment. Other errors – some in spelling and some more general –are indicated by “[sic]”. Where quotes are lengthy, specific references to the Leader or Lauderdale are often highlighted in red, specific references to the Turfford Burn in teal, and specific references to the main Tweed in blue.