The Impact of Flooding and Storms on Western Dorset Between December 2013 and February 2014
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Flooding and Storms The Impact of Flooding and Storms on Western Dorset between December 2013 and February 2014 (Observer Newspaper taken 6th Feb 2014) 1. Met Office - National Weather Picture December 2013 to January 2014 The first storm of 5 December brought very strong winds to Scotland and northern England, and a major storm surge affecting North Sea coasts. A week of quieter weather then followed, but from mid-December there was a succession of further major winter storms that continued into early January. Initially most of the weather impacts related to the strong winds, first across the north of the UK and then affecting exposed areas further south. However, as rainfall totals accumulated the focus of concern shifted from strong winds to flooding, including large river catchments such as the Severn and Thames. Finally, in early January, strong winds, combining with high spring tides and river flows, resulted in high water levels and large waves affecting exposed coastal communities in the south and west, causing coastal flooding. January to Feb 2014 Around 6 major storms hit through this period, separated by intervals of 2 to 3 days. The sequence of storms followed an earlier stormy period from mid-December 2013 to early January 2014. Taken individually, the first two storms were notable but not exceptional for the winter period. However, the later storms from early to mid-February were much more severe. Overall, the period from mid- rep_20140603_flooding and storms_2 1 Flooding and Storms December 2013 to mid-February 2014 saw at least 12 major winter storms, and, when considered overall, this was the stormiest period of weather the UK has experienced for at least 20 years. Strong winds and huge waves made conditions extremely dangerous around exposed coastlines - particularly in the south and west, and caused widespread transport disruption. There were major flooding problems, with the Somerset Levels continuing to be inundated with floodwaters from the New Year period. Severe flooding also occurred along sections of the River Thames. The Met Office issued a Red Warning for wind - the highest level of warning - for parts of North Wales and north-west England for the storm of 12 February 2014, while at the height of the storms more than 15 severe flood warnings were in place for the coast of southern England, the Somerset Levels and the Thames valley. 2. Environment Agency (EA) - Summary of recent severe weather Since 15 December 2013 the South West Region has had a prolonged period of rainfall, with only a few days of respite. For the Region as a whole it has been the wettest winter (December to February) on record. In February Wessex received 241% LTA rainfall, Devon and Cornwall received 209% LTA, and the South West had 221%, making it the fourth wettest February for the Region on record. Wessex has now had the wettest six months on record. River levels responded to the rainfall right across the Region, with all but one monitoring site recording exceptionally high mean flows for the month. Six flow reporting sites recorded their highest February monthly mean flows on record. The high flows resulted in numerous Flood Warnings being issued in both Areas. High tides and strong winds also resulted in many coastal Flood Warnings and a number of these warnings were of the severe category. Groundwater remains high, with all sites recording exceptionally high levels for the time of year. Soil moisture deficit remained at zero. Reservoir levels are at, or close to, capacity across the Region. Flood Warnings and Alerts In the months of December 2013, January and February 2014 the Partnership received more than 500 notifications from the EA. However, filtering to those that may have a significant impact on the Partnerships communities can reduce these. During the period from the 10th December 2013 and the 17th February 2014 the Environment Agency issued 115 Flood Alerts, 133 Flood Warning and 17 Severe Flood Warnings that were assessed as significant and need monitoring or further action by Technical Services Officers. All the severe warnings issued were coastally based. The definition of a severe flood warning is: There is a possibility of severe flooding with a danger to life or widespread community disruption. See Table 1 below Tidal Surges – Real Time Data On the 5th December 2013 a tidal surge of 2 meters threatened the East Coast (Lowerstoft) with the worst flooding in over fifty years. This phenomenon again became an influence in the South West of England when tidal surges of almost 1 metre affected the coast of Dorset. Below is the real time date from Weymouth on the 5th February 2014 showing the affect of surge on the predicated astronomical tide heights? rep_20140603_flooding and storms_2 2 Flooding and Storms Waves Two factors that influence the impact of the storms are wave height and swell period. The waves that impact the South Coast are generated far out in the mid Atlantic, what can dramatically influence their destructive power, when they eventually reach the shore, is the wave period or the distance between wave peeks; the greater the period the more destructive the waves can be. Thus: Total wave height = tide height + surge + wave height, and Potential wave impact is increased by a longer wave period. Table 1 – Details of Flood Warnings Date Severe Flood Flood Warnings Flood Alerts Warnings 10- 16/12/2013 0 1 4 17 - 23/12/2013 1 19 18 24 -30/12/2013 0 2 13 31 - 06/01/2014 5 45 24 07 -13/01/2014 2 3 1 14 -20/01/2014 0 4 3 21 - 27/01/2014 0 2 3 28 - 03/02/2014 0 13 12 rep_20140603_flooding and storms_2 3 Flooding and Storms 04 - 10/02/2014 5 26 18 11 - 17/02/2014 4 18 19 18 -24/02/2014 0 0 0 TOTALS 115 130 17 As a Professional Partner with the Met Office and EA the Partnership has access to high level information from the key agencies so that we are able to assess and predict possible impacts the sever weather on our Communities. These are sent directly by Fax and email or are available via the Met Office’s Hazard Manager secure website. Fig 1: Flood Forecasting Centre predictions for 13th February 2014 3. Local Weather - (Source Bob Poots Weymouth Meteorologist) December started out dry with a miniscule amount of rainfall in the first fortnight, the fifteenth saw 30.4mm, the greatest fall of the month. Rain fell on every day for the remainder of the month. Sunshine was sparse, just falling short of the December average. Winds during the first 11 days were light, strengthening for the remainder of December with gusts of over 20 MPH on most days. rep_20140603_flooding and storms_2 4 Flooding and Storms Temperatures were above average on nearly all days during December but the wind chill factor made it appear much colder. Winds were prominent during the second half of the month with gusts between 20MPH and 58MPH, with the highest being recorded overnight Monday 23rd. January, the second month of winter continued with the exceptional rainfall of December and emulated the extremely wet January of 2013. The last two months, December and January between them have delivered 355.3 millimetres of rain. The annual average is 744.8mm, this equates to half the years average rainfall in just 2 months. Winds were strong during the first week with gusts between 20MPH and 46MPH, and on all but 2 days during the second week, decreasing during the final fortnight of January, 46 MPH being recorded overnight Wednesday 1st 4. Legal Responsibilities of the Partnership under the Civil Contingencies Act 2004 The main civil protection duties fall on the Category 1 responders as follows: Risk assessment Business continuity management (BCM) Emergency planning Maintaining public awareness and arrangements to warn, inform and advise the public A fifth duty applies to local authorities alone: Provision of advice and assistance to the commercial sector and voluntary organisations Two further overarching duties are prescribed in the Regulations: Co-operation Information sharing As a service we recognize that it is important to learn form all incidents but as a direct consequence of lessons identified during the July 2012 flooding and experience gained throughout the 2012 Olympics Games; changes were made to the way the Partnership planned and responded to emergency incidents. Additionally, this particular severe weather incident spanned over nearly three months. Changes included: A SINGLE Partnership Emergency Planning team comprising; Head of Emergency Planning, and two Emergency Planning Officers. rep_20140603_flooding and storms_2 5 Flooding and Storms Improved joint working within the Partnership and with Dorset CC Emergency Planning Service Introduction of new Duty Officer systems Clarity of Command through the use of Gold, Silver and Bronze roles Better and more effective engagement with Local Resilience Forum (LRF) Partners, mostly using Telecom facilities Improved Communications both internal and external by the provision of a Communication’s Group Improving out of hours communication and information exchange using CLIO software, dedicated laptops (2012) and Blackberry phones dedicated to key roles Single point call handling for the Public and other Agencies through Magna Careline Targeted and more resilient arrangements for sandbag making and delivery Greater use of Community Sandbag Stores and volunteers Better understanding of arrangements with Dorset Waste Partnership and Highways and Contractors Upgrade software and control arrangements for Westham Sluices controlling the discharge from the River Wey Setting up Rest Centres Claiming emergency funding through Bellwin and other Government funds LRF Partners and their Role Category 1 Responder – These bodies are at the core of the response to most emergencies and are subject to the full range of protection duties in the Act.