Flood Investigation Report Tidal Surge Flooding Events on 5 December 2013 CES\FM009 June 2014 Flood Investigation Report Tidal Surge Flooding Events on 5 December 2013
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Revision Schedule
East Riding of Yorkshire Council Flood Investigation Report Tidal Surge Flooding Events on 5 December 2013
Rev Date Details Author Checked and Approved By Rev 1 Jan 2014 Initial Draft AM Rev 2 22 April 30th Final Initial Draft AM GP Rev 3 May 7th Draft Final Report AM MB Rev 4 May 19th Draft Final Report AM DJW Rev 5 May 27th CMT Consultation Draft AM NL Rev 6 May 29th Post EA Consultation Draft AM CMT Rev 7 June 10th Post CMT Consultation Draft AM DJW
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Copyright Notice
Maps in this report are reproduced from Ordnance Survey material with the permission of Ordnance Survey on behalf of Her Majesty’s Stationery Office Crown copyright 2008.
Unauthorised reproduction infringes Crown copyright and may lead to prosecution or civil proceedings. East Riding of Yorkshire Council 100023383.
Records of the public sewer system included are a facsimile of the statutory record provided by Yorkshire Water Services. For the purposes of this report minor sewers and other non- relevant data have been omitted from the plans for clarity. The statutory public sewer record is held by Yorkshire Water Services Ltd.
Acknowledgements
East Riding of Yorkshire Council would like to thank the following for their co-operation and assistance throughout this investigation.
The Environment Agency
Ouse and Humber IDB
Reedness and Swinefleet IDB
South Holderness IDB
Humberside Fire and Rescue Service
Humberside Police
Blacktoft Parish Council
Associated British Ports
Hull City Council
North East Lincolnshire Council
Lincolnshire Wildlife Trust
National Farmers Union
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Contents
Flood Investigation Report ...... 1 Revision Schedule ...... 2 Copyright Notice ...... 3 Acknowledgements ...... 3 Contents ...... 4 Lead Local Flood Authority and Responsibilities ...... 8 Relevant Flood Risk Management Authorities ...... 9 East Riding of Yorkshire Council ...... 9 Environment Agency ...... 9 Yorkshire Water ...... 9 Internal Drainage Boards ...... 9 Other LLFA’s ...... 9 Riparian Landowners ...... 10 Abbreviations and Acronyms ...... 11 Glossary ...... 12 Storm Surge...... 12 Spring Tides ...... 12 Design Standards and Return Periods ...... 12 Gold and Silver Group (Emergency Response) ...... 13 Strategic Co-ordinating Group (Gold) ...... 13 Tactical Co-ordinating Group (Silver) ...... 13 Damage Assessment Methodology ...... 13 Grade 1 and 2 Agricultural Land ...... 13 Grade 1 - Excellent Quality Agricultural Land ...... 13 Grade 2 - Very Good Quality Agricultural Land ...... 13 Data Analysis Carried Out To Inform The Report ...... 14 1 Executive Summary ...... 15 2 Location of Flooding ...... 18 2.1 Coast ...... 18 2.2 Humber (North Bank) ...... 19 2.3 Humber (South Bank) ...... 20 3 Flood Defences and Land Drainage Systems ...... 21 3.1 Environment Agency ...... 21
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3.2 Internal Drainage Boards ...... 21 3.3 East Riding of Yorkshire Council ...... 21 3.4 Coastal and River Humber Flood Defences...... 21 3.5 Review of the Flood Defences ...... 22 3.6 Analysis of the available Surge Data ...... 22 3.7 Land Drainage System ...... 24 3.8 Flooding History ...... 24 4 The Flooding Event ...... 25 4.1.1 Weather Data ...... 25 4.1.2 Climate Change ...... 25 4.1.3 Wind Speed and Wave Analysis ...... 26 4.2 Flood Warning System - Details ...... 27 4.2.1 Severe Weather Warnings ...... 27 4.2.2 Flood Warnings ...... 27 4.3 Review of the EA Flood Warnings ...... 28 4.4 Analysis Findings ...... 28 4.5 The Event ...... 29 4.6 The Response ...... 31 4.7 The Effects ...... 32 4.8 Coastal Defence ...... 35 4.9 Coastal Wildlife ...... 36 4.10 Outline Economic Assessment ...... 37 5 Outcomes ...... 38 5.2 Residential and Non-Residential Properties ...... 38 5.3 Other land-Use Types...... 38 5.4 Analysis Findings ...... 39 5.5 Limitations...... 39 5.6 The Recovery ...... 40 6 Help for Businesses and Homeowners / Repair and Renew Grant ...... 41 7 Causes and Investigation Findings ...... 42 7.1 After-Effects ...... 42 7.2 Lessons to be Learned ...... 43 8 Conclusions ...... 44 9 Recommendations ...... 46 9.1 Recommendation 1 ...... 46
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9.2 Recommendation 2 ...... 46 9.3 Recommendation 3 ...... 46 9.4 Recommendation 4 ...... 46 9.5 Recommendation 5 ...... 46 9.6 Recommendation 6 ...... 46 9.7 Recommendation 7 ...... 46 9.8 Recommendation 8 ...... 46 Useful Links and Contact Details: ...... 47 Appendix 1: Indicative Flood Extents in the East Riding of Yorkshire...... 48 Appendix 2: Properties Affected ...... 49 Appendix 3: Flood and Weather Warnings ...... 50 Examples of the Flood Guidance Statements issued in the early December 2013 ...... 51 Appendix 4: Photographs ...... 53 Appendix 5: Data Analysis by Capita ...... 66 Extract of the report from the Data Analysis carried out by Capita ...... 66 Rationale for analysis and outcomes ...... 67 Flood Defence Review ...... 67 Surge Data ...... 67 Wind Speed ...... 67 Asset Management ...... 68 Flood Warning ...... 68 Damage Estimation ...... 68 Flood Defence Review ...... 69 Introduction ...... 69 Data Review ...... 69 ...... 69 Methodology and Approach ...... 70 Results and Observations ...... 70 Conclusions ...... 70 Limitations ...... 70 Surge Analysis ...... 77 Introduction ...... 77 Methodology and Approach ...... 77 Wind Speed and Wave Analysis ...... 80 Introduction ...... 80
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Methodology and Approach ...... 80 Results and Observations ...... 82 05/12/2013 ...... 82 29/11/2013 - 30/11/2013 48 Hour Wind Duration ...... 83 Limitations ...... 84 Weather Online Data ...... 93 Weather Online Data ...... 94 Flood Warning Review ...... 95 Introduction ...... 95 Aims and Objectives ...... 98 Data and Approach ...... 98 Limitations ...... 98 Results ...... 99 Flood Warning Areas Not Warned ...... 99 Conclusions ...... 99 Assessment of the Flood Damage ...... 100 Outline Economic Assessment ...... 100 Methodology ...... 100 Results ...... 101 Residential and Non-Residential Properties ...... 101 Other Land-Use Types ...... 103 Conclusions ...... 104 Limitations ...... 105 Appendix 6: Wind Speed and Direction Map ...... 106 Appendix 7: Anecdotal reports ...... 108 Appendix 8: The Environment Agency’s Humber Flood Risk Management Strategy ...... 125 Summary of the Strategy ...... 125 Stated Aims and Objectives of the Strategy ...... 125 What does Managed Realignment involve? ...... 126 Appendix 9: Flood resilience information for property owners ...... 128 Appendix 10: Help for Businesses and Homeowners / Repair and Renew Grant ...... 129 Application Criterion ...... 129 Repair and Renew Grant ...... 129
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Lead Local Flood Authority and Responsibilities
East Riding of Yorkshire Council, as the Lead Local Flood Authority (LLFA), has a responsibility under Section 19 of the Flood and Water Management Act 2010 to investigate significant flood incidents in its area. Section 19 states:
(1) On becoming aware of a flood in its area, a lead local flood authority must, to the extent that it considers it necessary or appropriate, investigate -
(a) Which risk management authorities have relevant flood risk management functions, and
(b) Whether each of those risk management authorities has exercised, or is proposing to exercise, those functions in response to the flood.
(2) Where an authority carries out an investigation under subsection (1) it must -
(a) Publish the results of its investigation, and
(b) Notify any relevant risk management authorities.
(3) The LLFA has lead responsibility for managing the risk of flooding from surface water, groundwater and ordinary water courses.
This report has been prepared by East Riding of Yorkshire Council in its role as LLFA in response to extensive flooding which affected properties in:
• Bridlington • Skipsea • Hornsea • Tunstall
• Easington • Kilnsea • Paull • Hessle
• North Ferriby • Faxfleet • Blacktoft • Yokefleet
• Saltmarshe • Skelton • Old Goole • Reedness
As well as extensive areas of agricultural land along the coast and on both the north and south banks of the river Humber.
This report provides an overview of flooding that has occurred, describes the conditions which led to the flooding, considers the response to the flooding thus far and makes technical recommendations for the flood risk authorities concerned.
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Relevant Flood Risk Management Authorities
The risk management authorities that have relevant flood risk management functions are:
East Riding of Yorkshire Council
East Riding of Yorkshire Council is the Lead Local Flood Authority responsible for managing flood risk from surface runoff, groundwater and ordinary watercourses, development of a Local Flood Risk Strategy, Asset Plans and Investigations under the Flood and Water Management Act 2010. East Riding of Yorkshire Council also has responsibility for some Coastal erosion risk management, and is the Highway Authority with responsibility for highway drainage under the Highways Act 1980.
Environment Agency
Responsible for managing the flood risk from main rivers, the sea and reservoirs including coastal erosion risk management, permissive powers to maintain main rivers, strategic overview over all forms of flooding and development of a national Flood Risk Strategy.
Yorkshire Water
Yorkshire Water Services is the statutory sewerage undertaker for the Yorkshire region with a duty to effectually drain sewers pursuant to the Water Industries Act 1991.
Internal Drainage Boards
• Ouse and Humber • Reedness and Swinefleet • South Holderness • Goole and Airmyn • Thorntree Goole Fields • Dempster • Skeffling • Winestead Level.
Other LLFA’s
• Hull City Council - report published • North Lincolnshire Council - have prepared a report • North East Lincolnshire Council - not preparing a report at present • North Yorkshire County Council - awaiting confirmation
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In addition:
Riparian Landowners
Riparian landowners are those who own land adjoining a watercourse and have certain responsibilities, including the following:
• They must maintain the bed and banks of an open watercourse, and also the trees and shrubs growing on the banks. • They must clear any debris, even if it did not originate from their land, this debris may be natural or man-made. • They must keep any structures that they own clear of debris. These structures include culverts, trash screens, weirs and mill gates.
If they do not carry out their responsibilities, they could face legal action under the Land Drainage Act 1991. Details of a riparian landowners responsibilities can be found in ‘Living on the Edge’ published by the Environment Agency.
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Abbreviations and Acronyms
Abbreviations Description
AOD Above Ordnance Datum
Dia Diameter
EA Environment Agency
ERYC East Riding of Yorkshire Council
FCRM Flood and Coastal Risk Management
GWL Ground Water Level
HFRS Humberside Fire and Rescue Service
HVP High Volume Pump
LLFA Lead Local Flood Authority
IDB Internal Drainage Board
ABP Associated British Ports
Km Kilometre
Km2 Square Kilometres
Km/h Kilometres per hour
Ha Hectare
FWA Flood Warning Area
m/s Metres per second
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Glossary
Storm Surge A storm surge is an offshore rise of water level associated with a low pressure weather system, it is primarily caused by high winds pushing across the sea’s surface.
In the North Sea a storm surge is generated when a deep low pressure weather system tracks from the Atlantic Ocean to the north of Scotland and then sits over the North Sea producing a consistent northerly wind driving the waves southwards. There is also a slight raising of the sea level under the low pressure centre which contributes to raised sea levels, but the main effect is caused by the wind.
This drives the water down the North Sea which narrows towards the English Channel, this constriction funnels the water and causes a significant and rapid rise of the water levels, which is the storm surge.
A storm surge can happen whenever there is a low pressure weather system over the North Sea, however the effects are not normally noticeable unless the surge coincides with a high tide as was the case in December 2013.
Spring Tides The terms spring tide and neap tide refer to the action of the seas springing out and then springing back. These are times of greater tidal range, this means the tide comes in higher and goes out farther, it has nothing to do with the time of year or season, but is governed by the phases of the Moon. This is often referred to as the astronomical tide.
The tides on the oceans are largely as a result of the gravitational effect of the Moon, but the Sun also has a similar effect, although less than half as strong as the Moon's influence.
When the gravitational effects of the Sun and the Moon combine, we get spring tides, and the tidal range is at a maximum. A week later, during either of the two quarter Moon phases, when the Sun and Moon are at right angles to each other and their tidal influences partially cancel each other out, neap tides occur, and the tidal range is at a minimum. In fact, because the oceans take a bit of time to catch up to the geometry of the Moon, spring and neap tides usually occur about a day after the respective lunar cycles.
Design Standards and Return Periods Any flood defence is designed to a nationally accepted standard, this standard is often expressed as a return period (in years), or as an annual exceedance probability (a percentage).
For example, a 1 in 100-year event can be expressed as the 1% Annual Exceedance Probability (AEP) event, which has a 1% chance of the defence being exceeded in any year. 1 in 200-year event is equivalent to a 0.5% AEP. So a 1 in 200 year event actually has the same chance of happening in any year, irrespective of when such an event last occurred.
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Gold and Silver Group (Emergency Response) In the event of any significant incident or civil emergency, the emergency services co-operate in order to coordinate their responses to these events. In such circumstances strategic and tactical groups of senior representatives of the various organisations are called together to attend multi- agency command groups to co-ordinate activities, for the duration of the event. These are often referred to as Gold or Silver Groups, or Gold or Silver Command, with Silver Group reporting to Gold Group.
Strategic Co-ordinating Group (Gold) Multi-agency body responsible for co-ordinating the joint response to an emergency at the local strategic level which may be referred to as the Gold Group.
Tactical Co-ordinating Group (Silver) A multi-agency group of tactical commanders that meets to determine, co-ordinate and deliver the tactical response to an emergency. Note: the TCG may also be known as the Silver Group.
Damage Assessment Methodology The damage assessment was carried out using the Multi-Coloured Handbook (2013) weighted annual average damages (WAAD) method.
The Multi-Coloured Handbook is produced on behalf of the Environment Agency and Defra by the Flood Hazard Research Centre at Middlesex University.
Grade 1 and 2 Agricultural Land From the DEFRA guidelines for classification of Agricultural Land in England and Wales.
Grade 1 - Excellent Quality Agricultural Land Land with no or very minor limitations to agricultural use. A very wide range of agricultural and horticultural crops can be grown and commonly includes top fruit, soft fruit, salad crops and winter harvested vegetables. Yields are high and less variable than on land of lower quality.
Grade 2 - Very Good Quality Agricultural Land Land with minor limitations which affect crop yield, cultivations or harvesting. A wide range of agricultural and horticultural crops can usually be grown but on some land in the grade there may be reduced flexibility due to difficulties with the production of the more demanding crops such as winter harvested vegetables and arable root crops. The level of yield is generally high but may be lower or more variable than Grade 1.
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Data Analysis Carried Out To Inform The Report
Analysis of available data regarding the following was undertaken:
• Flood Defence Review • Surge Analysis • Wind Speed and Wave Analysis • Flood Warning Review • Assessment of the Flood Damage
A review of the Flood Defences was carried out to determine if the defences were fit for purpose.
An analysis of the available surge data was carried out in order to determine its magnitude, and its forecast effect on the reported flooding.
Wind speed and direction were analysed in order to estimate the forecast wave height, and to establish if wind driven waves contributed to the flooding event.
A review of the EA’s Flood Warning scheme was undertaken to determine if appropriate warnings were issued in a timely manner.
A high level assessment of the damages caused by the flooding was undertaken to gauge the economic effect on the East Riding communities and to assess the value to the area of the existing defences.
For further information about this data analysis please contact:
David J Waudby: Head of Infrastructures and Facilities, East Riding of Yorkshire Council.
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1 Executive Summary
During early December 2013 significant flooding was forecast by the Environment Agency based on Met Office weather forecasts and published astronomical tide levels, as it was anticipated that a storm surge could coincide with a spring tide. However the timing and height of the surge was difficult to forecast accurately as this was dependent on the prevailing weather conditions. This made issuing flood warnings for specific locations difficult.
In early December 2013 the Met Office and the EA were forecasting that a storm surge could coincide with a spring tide and that flooding was likely. Subsequently flood alerts were issued during the day on 5 December 2013 which were upgraded to Flood Warnings, and emergency plans implemented.
The forecast was for a deep depression (intense low pressure system) which had formed over the Atlantic Ocean, to track eastwards to the north of Scotland. It was being forecast that this weather system would create a storm surge which would travel in a southerly direction, down the North Sea coast coinciding with a spring tide. These same conditions were the cause of the devastating flooding around the North Sea coastline in 1953.
The timings of the high tide as it travelled south down the coast were as forecast, however estimating the timing and height of the surge was difficult as these were dependent on the changing weather conditions out to sea. Reportedly as the surge passed Aberdeen it was not as high as had been anticipated, however when it passed Gateshead it was higher than expected. This led to estimates of the height being recalculated, and the EA’s flood alerts and flood warnings were updated as a consequence. As the surge progressed down the coast with the tide, there was very little time in which to revise forecasts and update the flood warnings.
Following a Humber region teleconference on 4 December 2013, arranged as a result of the forecast, a Gold Group was established in Clough Road Police Station to co-ordinate the emergency services preparations. The Council Emergency Plan was implemented with a Silver Group established in County Hall to co-ordinate the Council’s preparations and response to the events.
Along the whole east coast some 1400 properties were flooded and 18,000 people evacuated with over 160,000 warnings issued by the EA. The water level at the Hull tidal barrier reached a record level of 5.8m AOD only 500mm below the top of the barrier.
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In most places, where flooding occurred in the East Riding (see Appendix 1) the high water levels overtopped the defences just before the high tide time. Flooding first affected commercial properties in Bridlington harbour, as the high tide passed south down the east coast. Around Spurn Point the headland was overtopped and flooding occurred in Kilnsea both from the sea and the Humber estuary. The flood defences along the Humber estuary were overtopped in places on both banks of the river; including at Paull, Hessle, North Ferriby, Faxfleet, Blacktoft, Yokefleet, Saltmarshe, Skelton, Old Goole and Reedness. In the East Riding a total of some 300 properties (69 commercial and 231 residential) were directly affected by flooding. Significant areas of agricultural land (estimated at 6000 acres or 2400ha) and caravan sites particularly along the coast were also affected, Hull City Centre also flooded.
Problems were reported all along the east coast, the River Hull tidal barrier and the Thames barriers were closed. The event exceeded previous levels in Hull for example, by a considerable margin. Infrastructure including roads, railways, power supply and sewerage services were affected. Estimated damage in the East Riding was in the region of £13.4 million. Many roads were closed during the event and some remained closed for several days as flood waters trapped behind defences slowly subsided, some were also blocked with stranded debris from the flood.
Anecdotal reports indicate that the flooding along the Humber happened very quickly, resulting in great distress, made worse by the fact it was at night, so people could not see what was happening around them. Reportedly people could hear a roar of the water approaching, then almost as soon as they realised something was happening the water was surrounding them.
The coastal and tidal defences were overtopped in places due to the height of the water, and in some places were damaged. However there was not significant cliff erosion evidenced immediately, but the clay cliffs were steepened which will subsequently result in further erosion in the coming weeks and months.
Some flood defence embankments along the Humber were damaged by the water overtopping them. All the embankments and defences were subsequently inspected by the EA and repairs were prioritised in anticipation of the next spring tide. There was serious concern among residents as the next spring tides, due on 3 January, were forecast to be higher than those on 5 December 2013, however no significant issues were being anticipated as without the tidal surge the levels were not forecast to exceed the defences, which proved to be the case.
In response to the event, the council deployed its recently acquired trailer mounted pumps to areas where the flood waters had become trapped behind the defences, and were not as a result draining away naturally. The EA and IDBs also deployed pumps in these areas with assistance from Humberside Fire and Rescue Service.
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As the flooding happened during the hours of darkness very few photographs of the event are available. However photographs of the affected areas were taken the next morning showing evidence of the extent of the flooding, including aerial photographs taken along the Humber and the coast by the EA on 6 December 2013 (see Appendix 4).
In the East Riding much of the land is below high tide level, and is protected by manmade defences and drained by manmade drainage systems. As a consequence these areas are vulnerable to flooding in exceptional circumstances or severe weather conditions such as those experienced in December 2013, an event which had not been experienced since the last very serious surge event in 1953.
The data analysis undertaken highlights that the estimated damages associated with the tidal surge are significantly less, (less than 1%) than those that could occur in the absence of any flood defences. This highlights the value of the existing flood defences in the East Riding and the benefits derived from continuing to invest in effective flood risk management measures.
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2 Location of Flooding
Flooding affected the following in East Riding:
• Bridlington • Skipsea • Hornsea • Tunstall
• Easington • Kilnsea • Paull • Hessle
• North Ferriby • Faxfleet • Blacktoft • Yokefleet
• Saltmarshe • Skelton • Sand Hall • Old Goole
• Reedness
North Yorkshire, Hull City, North Lincolnshire, North East Lincolnshire, Lincolnshire, Norfolk and Suffolk were also significantly affected.
See Appendix 1 - Indicative Tidal Flood Extents in East Riding of Yorkshire - December 2013.
Also Appendix 2 Properties Affected (Table).
Agricultural land around the coastal areas and along both banks of the Humber was affected, the long term effects of the flooding of agricultural land depends on the salinity of the flood water, duration of inundation and the characteristics of land itself as well as the intended crop.
2.1 Coast Bridlington the main area affected was in the harbour, which is open to the sea.
Skipsea some overtopping by wave action affected some properties on the cliff top, which were evacuated.
Ulrome some overtopping by wave action affected some properties, and some 80 metres of a private sea defence protecting a caravan park suffered extensive damage, and resultant erosion of the land. (See photographs 5 and 6 in Appendix 4). This resulted in debris across the beach, which was a public safety issue.
Hornsea although gates in the concrete wall flood defences had been closed by ERYC, the defence was overtopped by wave action and some flooding to commercial properties occurred on the south promenade.
Tunstall the defence consisting of earth banks was breached by wave action, and agricultural land flooded. The defence was repaired by the IDB with assistance from ERYC.
Kilnsea the earth bund at the caravan site was overtopped, and breached. In addition agricultural land and several properties in the vicinity were flooded. The banks along the Humber were also overtopped. This area of the East Riding is a peninsula bounded on both sides by open water; consequently it was inundated both from the coast and from the Humber. Spurn Point was overtopped cutting off the lifeboat station and ABP facility. Subsequently the roadway was lost where the overtopping occurred, and its future is uncertain.
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2.2 Humber (North Bank) Near Welwick, Weeton and Skeffling the defences were earth embankments, which were overtopped and breached, with some 200m of embankment washed away leading to extensive flooding to agricultural land (reportedly 1500ha). This is a proposed site for implementation of the EA policy of managed realignment of the defence, (See Appendix 8 Summary of the EA’s Humber Strategy) which would see a new main defence embankment inland with the existing outer bank deliberately breached to allow an area to become tidal, to act as a soft defence and an inter-tidal Saltmarshe habitat area.
Paull the defence was a concrete wall which was overtopped and both commercial and residential properties were affected.
Hessle the defence was a concrete embankment which was overtopped and both commercial and residential properties were affected. The Humber Rescue Station was amongst the properties flooded.
North Ferriby the defence was an earth embankment with rock armour, with an adjacent wall along the frontage of a car parking area. Both defences were overtopped and residential properties were affected. Part of the embankment is designed to be overtopped to allow water into a habitat area. Around the Ings Lane and Humber Road area there was a concrete wall which was not overtopped.
Faxfleet the defence was an earth embankment, which was overtopped, and agricultural land and residential properties were affected, and roads were flooded.
Blacktoft the defence was an earth embankment, which was overtopped. A short section of the embankment where an abandoned outfall had been, was damaged and subsequently repaired before the next spring tide. The village was virtually cut off, as the roads in and out of the village were flooded for a few days. It has been reported that the surface water drainage system within the village did not drain effectively and the system is currently being investigated by the IDB engineers supported by ERYC engineers.
Yokefleet the defence was an earth embankment, which was overtopped and much of the village was affected. Mobile pumps were deployed to help drain the flood water which became trapped behind the defences. The land drainage system was a pumped outlet which was overwhelmed.
Saltmarshe the defence was an earth embankment, which was overtopped. Agricultural land was affected and roads were flooded, as well as land around Saltmarshe Hall.
Skelton the defence was a steel sheet piled wall with an earth embankment, which was not overtopped although the roads were affected by seepage but not actually flooded.
Sandhall some properties were affected, when the river bank was overtopped.
Old Goole the defence was a brick wall, but although overtopping was not observed, some residential and commercial properties were affected.
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2.3 Humber (South Bank) Reedness the defence was an earth embankment and wall system maintained by the EA, which had been improved both upstream and downstream of the village. Although the work to improve the section of bank behind the village had been identified in the 2008 plan, indicating improvements should be carried out by 2023, it had not been initiated.
The result was that the unimproved section of embankment was overtopped and flooding to agricultural land and to properties in the village resulted. As flooding has now occurred and additional government funding made available, the works will be implemented as quickly as possible.
From the analysis of the event, and confirmed by anecdotal evidence, it appears that as the surge passed along the Humber and as the river narrows, the flooding occurred more suddenly. People were caught unawares, hearing a roar and then subsequently water flowing across open spaces at least at walking speed if not quicker. Many properties were flooded almost before the occupiers were aware of the situation, people reported opening an outside door to be confronted by water surrounding the property and then flowing into the house.
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3 Flood Defences and Land Drainage Systems
3.1 Environment Agency The EA has the strategic overview for flooding from the sea and main rivers. This means they are largely responsible for flood defences along the coast and main rivers, exercising permissive powers to carry out work to construct and maintain flood defences. There are manmade embankments along both banks of the River Humber which are at variable levels giving differing levels of protection.
The Flood Warning Centre, a partnership between the Met Office and the Environment Agency, provide a flood warning service based on weather forecasts and forecast river and tidal gauge levels.
3.2 Internal Drainage Boards The various IDBs within the East Riding are responsible for maintaining land drainage systems using permissive powers. This includes designated watercourses and pumping stations which discharge into the River Humber and the sea. Many of these drainage systems were overwhelmed by the flood waters which had overtopped the defences.
During the event the IDBs worked closely with the EA and ERYC in response to events, doing what was possible to ensure that pumps were running and deploying mobile equipment to assist the gravity outfalls and to remove trapped floodwaters.
3.3 East Riding of Yorkshire Council ERYC as Lead Local Flood Authority (LLFA) participated in the Gold Group structure, and set up a Silver Group in County Hall, to co-ordinate the council’s response to the events. Staff were out in vulnerable areas monitoring the situation and reporting back to County Hall. Where appropriate, flooded roads were closed for public safety and sandbags deployed. During the recovery the council’s six mobile pumps were deployed.
Rest centres were opened up and transport deployed to assist with evacuations if necessary. Vulnerable residents were identified and their needs assessed and appropriate support provided as necessary.
Following the event inspections of flood and coastal defences and affected highways were undertaken and repairs and clean-up operations arranged. Highway gullies in affected areas were cleaned, affected street lighting checked, and some roads cleared of debris.
3.4 Coastal and River Humber Flood Defences East Riding coastline is 85km long, of which just over 9km is defended, maintained by the Council. The Council also maintains defences along the North Bank of the Humber at Hessle Foreshore and North Ferriby, which are primarily to protect the public highway and car parking areas from erosion.
In most cases any new sea defence (and improvements to the embankments along the Humber) would normally be designed to provide a standard level of protection of 1 in 200, including a 30% allowance for climate change (depending on affordability). This is equivalent to a 0.5% chance of the defence being exceeded in any particular year. Most of the
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embankments are currently maintained by the EA to varying levels of protection, using permissive powers.
3.5 Review of the Flood Defences Summary of the Analysis (See Appendix 5).
The data used to identify and assess the flood defences in this report has been provided by the EA and forms part of its Asset Information Management System (AIMS) dataset. The AIMS dataset is supported by recent topographical survey of the flood defence crest heights and the elevations of other adjacent features. Both fluvial (river) and coastal defences are present in this dataset. The flood extents have been estimated by ERYC based on aerial photographs taken the morning after the event which were provided by the EA. The flood extent is only a best estimate and that in some areas could have been underestimated. Tidal Stage data (height) was utilised for all available gauges (measuring station) within the estuary and along the coast.
The main objective of the review was to first pinpoint areas where, based on surveyed elevations and observed tidal levels, overtopping of defences would have been expected. These areas have subsequently been compared to the anecdotal flood extent provided for the December 2013 event.
In general the forecast locations of flooding appear to match well with the anecdotal flood extents used in the analysis. The defence height review has highlighted the key areas where flooding has occurred and provides an indication of the crest heights in these locations. Using these heights it may be possible to draw some conclusions as to the contribution that the storm surge and wind driven waves may have had on the severity of flooding experienced on 5 December 2013.
There are some areas where defence heights imply that flooding should have been observed but where none is indicated in the indicative Flood Extents Plan (Appendix 1). This may be because flooding was no longer present at the time of the aerial photography or because the flooding was not as high as gauged levels elsewhere would imply. The way the surge propagated up the estuary led to higher water levels at certain locations in relation to others.
3.6 Analysis of the available Surge Data Summary of the Analysis (See Appendix 5).
The analysis made use of surge height data provided by the EA’s Flood Hydrology Fact Sheet 13: The Tidal Surge of 5 December 2013 (v2) and with gauged tidal data obtained from the British Oceanographic Data Centre (BODC). The fact sheet provides an indication of the difference between observed and forecast peak water levels, known as the Residual, and which indicates the height of the surge at the time of the peak tide. The BODC data provides a detailed record of the forecast tide and residual for Immingham and Whitby throughout the event.
The EA’s Flood Hydrology Fact Sheet makes it very clear that these surge heights presented were not the peak surge experienced on 5 December 2013 but the surge height at the time of the peak observed tide at these locations. Tidal Stage and Residuals plots obtained from
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the BODC were reviewed to understand the timing of the surge relative to the time of the high tide and to assess what might have happened had the surge peak coincided with the forecast astronomical tide peak.
Peak Tidal Astronomic Tidal Gauge Stage Time of Tidal Peak Forecast High Surge (m) 05/12/2013 Tide (m AOD)
Goole 6.04 05/12/2013 19:45 4.67 1.37 Blacktoft 6.01 05/12/2013 19:30 4.48 1.53 Hull Barrier 5.81 05/12/2013 19:15 3.88 1.93 Immingham 5.31 05/12/2013 19:00 3.61 1.70 Bridlington 4.56 05/12/2013 17:45 2.80 1.76
Table 1: Surge Heights at 5 Gauged Locations
Only two gauges along the East Coast were close enough to our site of interest and provided good quality data from the BODC to assess the timing of the surge, and the relative height of the surge; these were Immingham and Whitby. These two gauges were analysed by plotting the stage and residuals for 4 – 6 December 2013 and reading off the peak residuals (i.e. surge height) for each gauge.
A comparison of the two datasets, shows that the peak surge experienced at the two gauges is quite different, which is considered to be a reflection of the effect that the bathymetry (topography of the ocean floor) of the North Sea at Whitby relative to the bathymetry in the Humber Estuary. However the ‘lag’ between peak stage and peak surge is very similar, suggesting that the surge travelled down the coast at approximately the same speed as the astronomical tide did. Table 2 below presents the surge peaks and relative time between the peaks for Whitby and Immingham.
Lag Between Difference in Peak Surge At Surge Peak Residuals Peak Surge Surge and Surge at Observed Tidal and Observed Donor Site (m) time of Observed Peak (m) Tidal Peak Tidal peak(m) (Hours)
Immingham 1.97 1.587 0.38 +1.75
Whitby 1.63 1.48 0.16 +1.5
Table 2: Surge Analysis at Immingham and Whitby
As shown in Table 2, both gauges experienced peak surges before the forecast astronomical high tide had passed. In both cases the time between the peak observed tide and the tidal surge peak was similar (1.5 hours and 1.75 hours). In addition the time between the peak tidal surge and the forecast astronomical tidal peak was 1.75 hours at Whitby and 2 hours at Immingham.
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It can be said with some certainty that the tidal levels within the Estuary were higher than at Bridlington, and that the funneling effects of the Estuary on constricting the storm surge and raising sea levels, was more significant in the Estuary than along the coast. It could also be argued that the areas bordering the Estuary were not affected to the same extent, as had the peaks of the surge and astronomical tide coincided then the observed peak tide level could have been notably higher.
The appraisal of damages highlights that the estimated damages associated with the tidal surge are a little over 1% of those that could occur in the absence of any flood defences, which highlights the value of the existing flood defences to the region and the benefit derived from continuing to invest in effective flood risk management measures.
3.7 Land Drainage System Much of the land in the coastal area and along the Humber estuary is only just above mean sea level and in many cases is below the high tide level. The land drainage system in the East Riding is predominantly man-made except for the River Hull. With watercourses constructed to drain the land, where possible with a gravity outfall or as in many cases by the use of pumps to lift the water.
Most of the main watercourses (Main River) are maintained by the EA and others by the IDBs using permissive powers. The remaining watercourses are the adjacent landowners’ (riparian) responsibility.
The drainage system is designed to drain the land mainly to allow agriculture and in many places the system was overwhelmed by the inundation by flood waters coming over the defences. There are reports of some watercourses flowing backwards as the flood water entered the system. The flood waters did drain away through the system with temporary pumps deployed in some areas.
3.8 Flooding History A similar event occurred 60 years ago in January 1953.
During the night of 31 January 1953 a storm in the North Sea caused a storm surge which occurred at the same time as a high spring tide. Although the storm surge and high tide were forecast in advance, public warning systems were not very effective at that time and many people were not prepared for the flooding. More than 2500 people were killed around the North Sea coastline, including 307 in England and 19 in Scotland. As well as the loss of life, the flooding caused a great deal of damage to people's homes and businesses and affected large areas of farmland. At that time the amount of coast protection was very limited and not on the same scale that exists today.
Following the 1953 storm surge event, the UK Government invested much more in improved flood and sea defences, such as the Thames Barrier and the River Hull tidal barrier built in the early 1980s, together with more effective warning systems. This combined with the development of much more effective communications systems meant that in the latest event most people should have been aware and the emergency services better prepared.
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4 The Flooding Event
Figure 1: Conditions before the Event
4.1.1 Weather Data Synoptic situation at 0600 GMT on 5 December 2013, with a rapidly deepening low pressure system bringing very strong north-westerly winds to the northern half of the UK.
During the period leading up to the event the high winds associated with the weather system caused disruption and damage across much of the UK.
4.1.2 Climate Change Referring to the UK Climate Projections (UKCP09) information, which is the fifth generation of climate change information for the UK, funded by DEFRA and in conjunction with the Met Office.
It is widely accepted that the world’s climate and weather patterns are continually changing. This is resulting in both long and short term variability which gives rise to these natural variations which in turn often have significant effects on our lives. It is also known that over the past century there has been a trend towards an increase in global average temperatures. These have been projected to continue rising, which is very likely to cause continued changes in weather patterns: rising sea levels and increased frequency and intensity of extreme weather events.
This will increase flood risk; as a consequence many flood alleviation schemes are now designed with an allowance of up to 30% for climate change and rising sea levels. Schemes are climate-change proofed to ensure the design standard of protection will be delivered at least for the life of the defences.
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4.1.3 Wind Speed and Wave Analysis From the data available wind speeds were higher in Lincolnshire than they were in East Yorkshire. The wind speed and direction has a significant effect on the wave height and fetch (a measure of the distance over which a wave can be generated by a driving wind).
The winds were predominately westerly varying throughout the day from northwesterly to southwesterly. Had the winds been onshore instead of offshore, conditions could well have been much worse. As shown in the Analysis in Appendix 5, the wind speed was highest around mid-day and was much lower by the time of the high tide, although wave heights can take up to 12 hours to show any significant reduction, so this variation in wind speed did not affect the estimated wave heights used in the analysis
On 5 December 2013 the estimated wave heights were significantly higher on the coast than in the Humber estuary, as would be expected. Summary of the Analysis (See Appendix 5 and 6).
A number of key sites were selected for wave height analysis. These sites were selected with consideration given to the areas shown to flood during 5 December 2013 event, which were themselves derived from digitised aerial photographs of flooding provided to the council by the Environment Agency. In total 9 sites were selected for analysis.
Wave height estimates utilised the Groen and Dorrestein Manual Wave Forecasting Diagram, which is presented in Appendix 5. The method for estimating wave heights according to this forecasting model requires the user to obtain an estimation of the wind speed metres per second (m/s), wind duration (hours) and fetch (km). Fetch is a measure of the distance over which a wave can be generated by a driving wind. This data was obtained from weatheronline.co.uk.
The wave forecasting diagram (see Appendix 5) and the information available from weatheronline.co.uk suggests that wind-driven wave heights in open water within the estuary are likely to have been limited to 1m in height. Wave heights would primarily have been restricted by the available fetch relative to the general wind direction. Along the east coast, open water wave heights could have been significantly higher and may have been higher still when close to land where the water is shallower.
A review of the available wind speed and direction data indicates that the wind direction across the region on 5 December 2013 was generally westerly varying throughout the day from northwesterly to southwesterly, with a maximum mean wind force of 42 km/h. (See Appendix 5 and 6 Wind Speed and Direction)
Following the analyses presented in the surge analysis and flood defence review it is possible to further compare the contribution that wave heights may have had on the flooding experienced on 5 December 2013. The surge analysis has found that in general the surge heights greatly surpassed the required levels for overtopping of the defences to have occurred. This is true in particular for areas such as Faxfleet. As such, it is difficult to quantify the relative contribution of the wave heights in the estuary to the flooding experienced as tidal heights were already very high due to the significant storm surge. What can be said is that in the event that 1.0m waves were experienced in the estuary for any period of time, this could well have had an additional worsening effect on the extent and severity of flooding.
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4.2 Flood Warning System - Details The National Severe Weather Warning Service issues various warnings when forecast weather conditions are expected to cause disruption.
4.2.1 Severe Weather Warnings For heavy rainfall, high winds, fog, ice and snow etc.
• Yellow warning - be aware • Amber warning - be prepared • Red warning - take action
The joint Met Office and Environment Agency Flood Forecasting Centre provide a flood warning service based on weather forecasts and forecast river and tide levels.
The EA routinely issue alerts and warnings for forecast flooding, with warnings graded dependent on the expected severity.
4.2.2 Flood Warnings • Flood Alert, flooding is possible. Be prepared. • Flood Warning, flooding is expected. Immediate action required. • Severe Flood Warning, severe flooding. Danger to life. Usually issued in consultation with Gold Group.
Weather warnings had been issued together with Flood Alerts on 4 December 2013.
It should be noted that not all affected residents were registered with the EA for Flood Warnings. Those who were registered did receive some warning, although anecdotal evidence indicates some warnings were not issued in a timely manner. This was understood to be due to the difficulties experienced by the EA in forecasting the timing and height of the surge.
Information from the EA would indicate that defences were in a serviceable condition and were providing effective flood protection, although to a variable standard and had been performing satisfactorily with no reported flooding at times of normal spring tides.
Flood Alerts which are catchment specific had been issued for the whole of the east coast of England. As the event developed Flood Warnings for specific areas, including parts of East Yorkshire, Lincolnshire and both banks of the Humber were issued throughout the day on 5 December 2013. Subsequently Severe Flood Warnings were issued for specific communities.
Reportedly by the time some people received these warnings they were already flooding, with not all residents signed up to the warning scheme.
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4.3 Review of the EA Flood Warnings Summary of the Analysis (See Appendix 5)
Flood Warnings are a vital tool used by the EA to warn communities of forthcoming flooding affecting certain areas. EA Flood Warnings fall under three classifications based on the severity of flooding expected. The three levels of warning are:
• Flood Alert – Flooding is possible. Be prepared • Flood Warning – Flooding is expected. Immediate action required • Severe Flood Warning – Severe flooding. Danger to life. Usually issued in consultation with Gold Group.
Flood warnings are issued when certain water levels at tidal and river gauges are forecast to reach a given level – this measurement is known as the Threshold Level. Threshold levels may be in metres (the height of water above or below the gauge datum) or in metres above Ordnance Datum. As flood warnings are issued, various operational procedures are put into action – for example sand bags may be dispensed, a flood gate could be closed to protect an area from flooding, or the fire brigade may be called to an area to help pump flood water away from properties. It is crucial therefore that the threshold level used by the EA is suitable for the area being warned. Suitable thresholds should be set at a level that allows enough time for communities to be warned and for the procedures used to manage flooding to be effectively carried out. Thresholds should not be so low that communities are needlessly warned of flooding and not so high that sufficient time is unavailable prior to flooding affecting a community.
Severe Flood Warnings are issued when there is deemed to be a significant risk to life in an area. This is a subjective decision made jointly by the EA and their professional partners. There are no specific level thresholds that would trigger the issuing of a Severe Flood Warning.
In total 47 flood alerts or flood warnings (both normal level and severe level) were issued to 24 Flood Warning Areas (FWAs) during 5 December 2013 along the East Coast, north of the Humber estuary and along both north and south banks of the estuary itself from its mouth at Spurn Point upstream as far as Skelton and Howden Dyke.
During the review, two areas were identified that did not receive flood alerts or warnings but which were shown to coincide with the flood outlines from the storm surge and high tides of 5 and 6 December 2013. These two community areas were in Hornsea and Saltend. Closer inspection has shown that digitised flood outlines overlap in very small areas of the two FWAs, suggesting that these areas were not actually flooded.
4.4 Analysis Findings Of the 14 community areas reviewed that received alerts or warnings during the storm surge and high tides of 5 and 6 December 2013, the information shows that most communities received warning of flooding prior to maximum gauge levels being reached, namely communities were given sufficient warning of the forthcoming flooding. Some received second warnings or an escalation to a Severe Flood Warning just before the maximum gauge level was reached: some communities may have been warned of flooding or severe flooding too late.
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In some cases, the information suggests that less than an hour was given between warnings being issued and gauge maximum levels being reached, for example Spurn Point. It is particularly notable that locations in the vicinity of Hull, where an early flood warning was issued but when followed up with a Severe Flood warning or second Flood Warning this often took place just before the maximum gauge level was reached. This was also the case at:
• Broomfleet • Faxfleet • Blacktoft • Bridlington
• Easington • Kilnsea • Spurn Point • Brough
• Hessle • Hessle Haven
On the north bank of the Humber estuary at Paull and Paull Holme Strays, the north bank of the River Ouse at Saltmarshe, Sand Hall, Skelton and Kilpin Pike and the north bank of the Humber estuary at North Ferriby FWAs. The review has determined that while flood warnings were issued ahead of maximum gauge levels being reached, some severe flood warnings were received within only one hour of the maximum.
It is recommended that operational procedures be reviewed to determine whether improvements to the timing of warnings and particularly Severe Flood Warnings in relation to threshold levels can be made and particularly in those areas where Severe Flood Warnings were only made at or around the time of the peak.
4.5 The Event During the day on Thursday 5 December 2013 the Flood Warnings were issued in addition to the existing Flood Alerts as the forecasted storm surge was being forecast to coincide with the evening spring tide. As the surge passed down the east coast of Scotland the levels were lower than had been forecast. There was still some doubt however about the expected height of the water as the strength and direction of the prevailing winds at the time of the high tide would have a significant effect on levels.
The high tide was due at Spurn Head at 18:54 and at Goole at 20:32. Flooding occurred approximately 30 minutes before the expected high tide times, due to the combination of the tide level and the storm surge. The recorded tide level at the River Hull tidal barrier was 5.8m AOD the previous record level was 5.1m.
The severe weather had already caused problems in Northern Ireland, Wales and Scotland due to the high winds, resulting in two deaths. There was flooding all along the east coast, as well as on both banks of the River Humber, and Spurn Point was overtopped (see photograph 1 below).
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Photograph 1: Spurn Point seen from the air on 6 December 2013
As the high tide progressed down the coast and along the Humber with the effects of the storm surge, some 30km of the defences were overtopped in several places.
Eyewitness accounts at Reedness indicated that the water level rose steadily until just before high tide and then rose dramatically leading to the overtopping. This would be consistent with the storm surge arriving just before the astronomical high tide time.
Many areas were quickly inundated with significant depths of water flowing through villages, resulting in property flooding and much debris being washed across the surface. (See Appendix 1 - map showing extents of flooding).
There is anecdotal evidence of people having to evacuate their homes as water surrounded their properties or entered it. There are also anecdotal reports (see Appendix 7) of neighbours helping vulnerable people to escape the flood as emergency services struggled with the scale of the event. The speed of the surge travelling up the river meant that even as reports of problems were received, the flooding had moved farther up river.
Due to the geography of the East Riding much of the land is below high tide level and is protected from flooding by manmade defences and land drainage systems including pumped outlets, so some areas are particularly vulnerable to flooding.
Once the defences had been overtopped the water spread out across the flat agricultural land behind them, resulting in the flooding of an estimated 6000 acres (2400ha) of agricultural land.
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Photograph 2: Aerial photo looking north towards Blacktoft on 6 December 2013
Some defences were damaged and some drainage outlets became blocked with debris which prevented the flood water draining away in some places until it had been cleared.
As the event developed ERYC operational staff were deployed in key areas to observe and report back to the Silver Group in County Hall, where it became apparent that flooding was imminent. The staff began door knocking to warn as many residents as possible.
Hull City was affected, although the River Hull tidal barrier was not overtopped, flooding occurred when the defences at Albert Dock were overtopped. The water level at the barrier was recorded at 5.8m AOD, only 0.5m below the top of the barrier. This is the highest tide level ever recorded there.
Significant areas of agricultural land flooded, in particular where the river narrows near to Goole, as the land is flat. The surge wave may have amplified as it passed upstream and as the channel narrows the water level rose overtopping defences.
There was reportedly flooding along the River Trent and the River Ouse as the surge passed up river.
4.6 The Response Gold Group established in Clough Road Police Station.
Silver Group established in County Hall to manage the Council’s response to events as they developed.
During the event all the organisations involved, including ERYC, EA and the IDB’s co-operated and worked together with the emergency services to safeguard residents and to clear the flood waters as quickly as possible. This multi-agency co-operation continued throughout the event and the recovery period.
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The council’s Emergency Plan was implemented with evacuations arranged for affected residents. Rest centres were opened, some 5000 sandbags were delivered to affected areas and some roads were closed for public safety, and mobile pumps deployed as part of the recovery.
Staff were deployed to vulnerable areas to monitor the developing situation and report back to the Silver Group, also warning residents of imminent flooding.
4.7 The Effects In total some 300 properties (69 commercial and 231 residential) in the East Riding reportedly were directly affected by flooding. The analyses indicate that nearly 600 properties lie within the areas shown to have been affected. Significant areas of agricultural land (estimated at 6000acres or 2400ha) and some caravan sites particularly along the coast were flooded. As a result properties, caravans and crops were damaged, some livestock and pets were lost, any possible longer term damage to farmland has yet to be determined, businesses were disrupted. Reportedly some livestock had to be moved to higher ground and in some cases even then were subject to flooding. Agricultural machinery, buildings, fences, stores of crops, fodder and fertilizer etc were also damaged, open areas and ditches were filled with debris and silt. Many areas including highways, farmyards and garden areas were covered with silt and required extensive cleaning.
Many people were put at risk as they struggled through the flood water, some trying to offer assistance to neighbours or attempting to protect property, livestock etc. and in particular trying to reach flooded areas driving along flooded roads in the dark. Many vehicles were stranded and abandoned in flood waters on the roads, others were flooded beside properties.
There are anecdotal reports of people struggling through deep and rapidly rising water or trying to reach vulnerable neighbours. There are also reports of residents trying to help each other and of the efforts of the emergency services which were stretched by the volume of calls for help and the extremely difficult conditions on the night. Reportedly various services experienced difficulties with vehicles trying to reach locations only to find routes blocked by the flood water.
Residents have reported that the long term effects of the flooding, the stress and worry is having an adverse effect on their health and some residents are so upset that they no longer wish to live in the affected villages. Dealing with the clean-up and insurance claims etc. as well as the fear of a recurrence are all affecting vulnerable people.
In the short term the apparent damage to farmland does not appear as bad as was forecast bearing in mind some areas were submerged for several days. However the long term effects of the flooding of agricultural land is difficult to assess and will not be fully appreciated for a number of years, when crop yields have been assessed.
The immediate effects include loss of some livestock, damage done to equipment, stores, fences and buildings. The quantity of debris washed onto land and into ditches, resulting in restricted grazing for livestock, also possibly causing blockages in the drainage systems.
As the flooding happened during the winter the effects on agriculture are likely to be less extensive than if the same event were to have happened at other times of year.
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When agricultural land is submerged it can cause slumping (where the structure of the soil is compressed) which will require extensive work to re-open the soil structure to allow air into the soil, on grassland this is not possible. There is also the effect on the flaura and fauna, insects and wild plant life in the field margins, micro-organisms living in the soil, which assist the breakdown of fertilisers. For instance where salt water submerged the land the earthworms were killed.
There is some concern that in the medium term the viability of some businesses may have been affected. As the value of land could be reduced by the perceived increase in flood risk, this could affect their ability to raise capital to fund the business.
Where salinity of the flood water has contaminated the land this can be mitigated by applying gypsum, but overall the adverse effects may well be longer term.
The Council attended the affected areas. Based on the information given by the EA through Gold and Silver Groups, staff were mobilised in the morning to identified vulnerable areas which were more or less where the issues appeared. Sandbags were delivered to all of these locations, an estimated 5000 in total.
Work was undertaken digging out, debris clearing, sweeping of roads at:
• Withernsea • Hornsea • Kilnsea • Hessle • North Ferriby • Paull
and also re-emptied gullies in all areas affected by washoff/silt/sand. Street lighting in flooded areas was also checked.
Many roads in the areas listed below were closed on the day, longest closures were particularly in the areas below:
• Kilnsea • Blacktoft • Faxfleet • Yokefleet • Saltmarshe
Some of these roads were closed for approximately five days, as pumping operations to clear the flood waters continued.
Reactive works, in the following areas, including road closures, sweeping, gully cleaning, debris disposal, equipment hire, fuel etc. cost approximately £95,000.
• South Promenade, Hornsea • Greenoak Lane, Yokefleet • Faxfleet Lane, Faxfleet • Moorfields Lane, Saltmarshe • Humber Road, North Ferriby
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• Cliff Road, Hessle • Spurn Road, Kilnsea • Easington Road, Kilnsea • Reedness • Humber Lane and Winsetts Lane, Skeffling • Humber Side Road, Weeton • Row Lane, Welwick
Costs for permanent repair works planned to be undertaken to damaged roads/bunds and footways including those at, Blacktoft, Kilnsea, Yokefleet, Reedness, Faxfleet and Easington - Estimated at £425,000.
Council Bridge Engineers reported that Boothferry Bridge was damaged by water ingress into electrical equipment and silt/sand build up under the structure.
The Humberside Fire and Rescue Service reportedly received 285 calls for assistance on 5 December 2013. This was across the whole Humber region including East Riding, Hull City and North and North East Lincolnshire.
Some 137 calls were received regarding weather related incidents; 80 calls relating to flooding and 57 to the high winds experienced on the day.
The service rescued 33 people from flooding incidents and evacuated approximately 55 people.
Police - there were 71 incidents reported of which 65 were weather or highways related, and a section of the A63 was closed overnight on 5 and 6 December 2013.
Northern Power Grid reported disruption to supplies due to wind damage to overhead lines and then delays in restoring supplies due to difficulties experienced accessing equipment safely.
Yorkshire Water Services reported that some drainage systems were overwhelmed by the flood water but the systems drained down. Some pumping stations were also overwhelmed at Hessle Foreshore, Paull and Easington. The pumps at Hessle Foreshore were submerged, the flood damage was repaired once the flood waters receded and safe access was possible.
Network Rail reported disruption to services and some damage to equipment. Although damage to electrical equipment was limited where the supply had been switched off prior to the flooding. Significant damage occurred to a swing bridge in Goole due to flooding and sand ingress. Some damage was done to the track in various locations where ballast was washed out (damage estimated at £100,000).
Associated British Ports and the Royal National Lifeboat Institution - the access road along Spurn Point was washed away where the peninsula was overtopped, and due to the amount of lost material and given the wave action its future may remain uncertain.
Internal Drainage Boards - In general the IDBs deployed staff to monitor the situation and where possible to ensure that their pumps were operational. In the recovery operation they deployed mobile pumps and cleared drainage channels and outfalls to assist the drainage of the flood waters.
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Ouse and Humber IDB reported in the Faxfleet to Saltmarshe area, the extent of the flooding was indicated by stranded debris up to a one mile inland, and in places flood water had been up to 1.5m deep. Some roads were impassable due to the depth of the flood waters. In order to relieve pressure on flooded properties and assist in reopening Greenoak Lane, it was decided to open a temporary trench from flooded farmland into the Board’s adjacent pumped system. In addition, deploying 15 temporary pumps in the area alongside the EA and the council’s mobile pumps.
South Holderness IDB reported flooding from the coast and they rebuilt some defences on behalf of the EA. They also repaired the breach in the present defences at Welwick in consultation with the EA, Natural England and the council, by clearing deposited material from the drainage ditch at the back of the embankment.
IDBs reported that some watercourses which discharged to the sea were blocked with debris deposited by the surge and had to be cleared to allow discharge.
4.8 Coastal Defence The council maintain a number of structures on the coast, some of which were damaged as a result of the surge:
• Flamborough Head, rebuild damaged steps • Bridlington, rebuilt step block, seawall and foundations • Hornsea, repaired floodgate, handrail and terminal structure • Withernsea, repaired floodgates, handrail and access track • Kilnsea, Crown and Anchor, Humber banks rebuilt rock revetment
In addition at various locations along the coast, increased general maintenance works were undertaken. The total estimated costs of the above works was in the order of £125,000.
An 80m section of private seawall at Skipsea/Ulrome collapsed (see Appendix 4, photograph 5 and 6).
• Tunstall earth embankment was breached (then repaired by IDB) • Kilnsea caravan site earth embankment washed away
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Photograph 3: Council staff surveyed the coastal erosion, showing the steepening of the cliffs
Although there was not a significant loss of cliff discerned immediately after the surge, the longer term stability of the cliff will have been compromised and further erosion is expected as the cliffs stabilise. An estimated £150,000 was incurred to make safe private defenses destroyed by the surge. In general the hard defences stood up well with some minor damage.
4.9 Coastal Wildlife Although a storm surge had been forecast, the full magnitude of the event was greater than anticipated. Many nature reserves and habitat areas were badly affected by the storm. With the high winds causing disruption and damaging trees and hedges, the inundation of freshwater areas by storm driven seawater caused damage to habitats and visitor facilities, with damage to paths, bird watching hides, gates and fences, notice boards and buildings. The longer term damage to ecosystems due to saline inundation is more difficult to assess.
A report by Natural England concluded that the winter storms had affected at least 48 Sites of Special Scientific Interest. Although it should be noted that the flooding of Saltmarshe areas with seawater may well have a positive impact on those habitats.
An estimated 30,000 seabirds were killed by the storm surge in the North Sea, although the RSPB at Bempton reserve reported little impact as the birds there had not started to breed. Had the storm arrived a few months later the situation would have been much worse.
At Donna Nook seal colony many of the mothers and pups were stressed by the storm, and some were separated. Fortunately very few pups appear to have died, however some older pups are believed to have gone to sea early. Longer term affects are more difficult to gauge as any disturbance of habitat and food supplies may affect wildlife in the future. CES\FM009 Page | 36 Flood Investigation Report - Tidal Surge Flooding Events on 5 December 2013
Staff and volunteers have been working hard at many locations to clear away debris and attempting to restore the sites, to enable the wildlife to flourish and visitors to return.
4.10 Outline Economic Assessment Summary of the Analysis (See Appendix 5).
As part of the investigation into the tidal surge, an assessment has been made of the number of residential and non-residential properties shown to lie within the digitised extent of flooding along with an outline assessment of the economic impact of that flooding. This has been compared to similar analysis applied to those properties that lie within the 1 in 200 year standard of protection. The undefended tidal flood extent – derived from the Environment Agency’s Flood Zone Map – has been analysed in order to identify the potential impact that such a significant event could have had on property within the East Riding of Yorkshire had there been no defences. The aim of the analysis was to put the properties and estimated damage into context by comparing it to what could have been. The analysis indicates the level of benefit that the existing defences provide.
It should be noted that there was only sufficient information to undertake an overview level assessment of the potential damages experienced in the event and that the damages to other assets and infrastructure was not considered, namely:
• Electricity and gas transmission infrastructure • Water and sewage treatment infrastructure • Impacts on roads and rail infrastructure • Telecommunications • Schools and Hospitals • Agriculture and recreation
Further discussion is presented later in this summary of the impacts of the different flood events on each, despite not quantifying the damages as only an overview level assessment was carried out.
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5 Outcomes
5.2 Residential and Non-Residential Properties The results of the analysis indicated that the impact of the tidal surge was significant. At least 593 properties were shown to be located within the flood extent. However the number may be more because the flooded areas were based on digitised aerial photographs of the flood extents taken more than 12 hours after the surge peak, on the morning following the event, as the flood waters had receded.
Using the WAAD (Weighted Annual Average Damages) approach, the direct-damage estimate, namely the damage sustained to the buildings and their contents, to residential and non-residential properties is estimated to be in the region of £8.8 million, with a further £1.8 million of indirect and intangible damages. The total damage is estimated to be in the region of £10.6 million.
It is notable that, whether the WAAD approach is taken or a relatively low-depth assessment of potential damages using a depth estimate, the damage estimate based on the digitised flood extent from the 2013 surge is not significantly higher than 1% of the potential damages that might have occurred in an undefended scenario. Comparison of the two damage estimates (surge against Flood Zone Map) indicates that the damages avoided by the presence of the defences was at least £600 million, if not more.
It is likely that this figure would be reduced further by considering the extent and consequences of flooding from failure of the defences under these conditions. Despite this, it can be seen that the presence and continued maintenance of the tidal defences provides a significant benefit to the East Riding of Yorkshire.
5.3 Other land-Use Types Electricity and gas transmission infrastructure – There are four electricity sub-stations of up to 400KW located within the Tidal Flood Zone Map. Based on their size, three of these are likely to be Super Grid substations serving a large number of people, however, whilst susceptible to flooding there may also be a degree of transferability, which could reduce the impact of flooding upon them and the electricity grid in general. None of the four were affected by the December 2013 tidal surge.
The National Receptor Database also indicates almost 200 smaller electricity sub-stations within the Tidal Flood Zone Map, however, only two were shown to lie within the December 2013 tidal surge flood extent.
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Water and sewage treatment infrastructure – within the Tidal Flood Zone Map the following facilities are present:
• 1 water storage facility • 2 water treatment facilities • 2 water distribution facilities • 5 sewage pumping facilities • 2 sewage treatment facilities • 22 pump houses • 60 pumping facilities
Of the above assets, only 1 pumping facility is shown to have been affected by the recent tidal surge.
Impacts on roads and rail infrastructure Agricultural Land – The areas impacted by the surge are largely rural in nature and an analysis of the agricultural land classification of the areas inundated in comparison to the Tidal Flood Zone Map show that there was a notable impact on high quality agricultural land.
5.4 Analysis Findings The assessment has identified that there was a significant number of properties affected by the tidal surge. Nearly 600 properties lie within the area shown to have been affected with an approximately 50:50 split between residential and non-residential uses. The direct damage to these properties caused by the flooding is estimated to be in the region of £8.8 Million, with additional indirect and intangible costs of approximately £1.8 Million (WAAD approach).
The appraisal highlights that the estimated damages associated with the tidal surge are a little over 1% of those that could occur in the absence of any flood defences, which highlights the value of the existing flood defences to the region and the benefit derived from continuing to invest in effective flood risk management measures.
The assessment highlights that there was relatively little impact from the tidal surge on important infrastructure, with only minor impacts on small electricity sub-stations, a pumping facility, and no impacts on schools or hospitals. However, there was a notable impact on roads in the inundated area with the consequences felt most acutely on local roads and streets and private roads. Grade 1 and 2 agricultural land was also heavily impacted.
5.5 Limitations The assessment is an overview level assessment, considering primarily the damages to residential and non-residential properties, as these are the land-use types for which damages are easily available. There would have been additional costs that have not been assessed within this study, such as those associated with impacts on the infrastructure identified above, impacts on agriculture and farming, disruption to travel, schools and local recreation and tourism, loss of business revenue. There would also have been direct damage to flood defence infrastructure.
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5.6 The Recovery The Council’s Recovery Team was brought together on the morning of 6 December 2013 and teams were deployed to door-knock in flooded locations that morning. Every known flooded property had been visited by Saturday, 7 December 2013.
The 18 recovery teams were able to identify residents that needed particular support and provided others with information regarding access to various council services such as:
• Bulky collections, provision of skips, movement of heavy damaged goods. • Emptying septic tanks. • Providing portaloos. • Street cleaning. • Providing food parcels and cleaning equipment. • Providing information on available services such as local welfare support.
Recovery work continued into the next week supporting residents with various issues.
The council’s mobile pumps were deployed to drain water which had become trapped behind flood defences.
The EA and the Council’s Coastal Risk Management teams worked jointly in carrying out qualitative inspections of defences, assessing damage and prioritising necessary repair works.
The IDBs worked in co-operation with the council and the EA, to ensure that flood waters drained away as quickly as possible. At a number of locations mobile pumps were deployed to assist. The pumped drainage systems reportedly drained down much quicker than the gravity systems, which in turn remained flooded for a number of days. Many ditches and watercourses had to be cleared of debris washed in by the flooding, to allow the water to drain away. In the Ouse and Humber IDB area a temporary connection was made between two separate systems to allow water to drain away more effectively.
In the affected areas the highway gullies were cleaned out by the council after the event, this was in addition to the routine annual cleaning of these gullies.
Meetings were held with many of the communities affected to listen to residents’ concerns, and to provide information and advice regarding recovery works.
Government has announced a number of flood relief schemes to help homeowners and businesses impacted by flooding between 1 December 2013 and 31 March 2014.
• Support for Businesses • Help for Homeowners/Repair and Renew Grant • Business Rates Flooding Relief • Council Tax Discounts • Business Support Scheme • Farming Recovery Fund • Support for Local Authorities
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6 Help for Businesses and Homeowners / Repair and Renew Grant
There is a government funded flood support scheme grant available of up to £5,000 per flooded property. The council has sent an application form with an explanation of the process to each property recorded as flooded. The process which the residents will be expected to follow is fully explained in the accompanying literature.
The Council is administering the scheme in the East Riding, a cross departmental working group has been established which meet on a regular basis in order to co-ordinate, implement and administer the scheme.
More information and grant application forms are available on the ERYC Website, on the A to Z, F - 8 Flooding, Flooding Support Scheme, “How can I apply”, see also Appendix 10.
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7 Causes and Investigation Findings
The combined effects of the storm surge and spring tide were the overriding factors in the flooding experienced on the 5 December 2013. Furthermore, the effects of timing were substantial and the approximately two hour lag between the surge peak and the astronomical peak was responsible for reducing the peak tide levels by almost 0.4m in the Humber Estuary. The effects of a higher tide level of this magnitude would have been overtopping across a wider area and much more significant consequences across a wider area of the coastline.
Extremely high water levels resulted when a storm surge coincided with a spring tide, to raise water levels to such a height that they overtopped the coastal and flood defences in several places, with a total of approximately 40km of defences overtopped along the estuary, the majority being within the East Riding. The spring tides are a part of the normal tide cycle driven by the phases of the moon, and a storm surge is not unusual during the autumn and winter months. However the rare combination of tide time, atmospheric pressure, storm track and wind direction such as happened on 5 December 2013 are unusual, but in this case had been forecast and flood alerts and warnings were issued, however the severity of the effects were not fully appreciated until late in the day.
Had the wind been blowing onshore instead of offshore, this would have resulted in wind driven waves, leading to increased wave heights. Flooding and damage to defences would almost certainly have been significantly worse.
Similarly had the storm surge arrived at the time of the high tide, resultant water levels would have been higher still, and flooding would have in turn been significantly worse, and more widespread, with consequently increased risk to life and damage to property.
Flood warnings were issued for all affected areas, however some warnings along the Humber were only issued within an hour of the highest water levels. It should be noted that not all affected residents were signed up for alerts from the EA.
An analysis of available data indicates that the flood defences were in general fit for purpose. Despite the overtopping relatively little damage was done to the defences themselves.
The analysis also indicates that although the damage done in the East Riding was extensive, it would have been far worse if the existing flood defences had not been in place or if the surge had coincided more closely with the high tide.
7.1 After-Effects Where the defences were overtopped flood water was then trapped behind them once the sea and river water levels had dropped as the tide receded. The flood water then drained down through the land drainage system, with mobile pumps being deployed where necessary to move the trapped water and to assist the existing drainage systems many of which have pumped outlets.
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As the flood water in many areas was partly sea water the salinity may well cause problems where agricultural land was flooded. It remains difficult to gauge the extent of the problem at present as the degree of salinity of the flood water is not known and the effects on the soil and the specific crop will not be known for some time. In many areas the salt water caused earth worms to be washed out of the soil, which are an essential part of the soil ecosystem.
In places where the defences were damaged repairs were carried out by various bodies including the Council, EA and IDBs, in some cases acting on behalf of the EA.
At Reedness a section of embankment had previously been identified by the EA’s Humber Strategy to be improved before 2023, but the work had not been undertaken. Flood water overtopped the unimproved section of the embankment and flowed through the village.
As flooding has now occurred, and additional government funding made available this improvement work will now be implemented as early as possible. Significant damage was also done to banks of the IDB maintained Reedness Drain when the flood waters which flowed through the village flowed overland into the drain causing bank slippage. The cost of the repairs is estimated to be at least £300,000.
At Welwick sections of embankment under consideration to be realigned as part of the managed realignment were breached and temporary repairs undertaken in light of the forecast high tides on the next lunar cycle. This work has now been completed.
In general terms the flooding was a result of overtopping of the defenses rather than breaches, with subsequent damage caused to some embankments and structures by the flow of water.
7.2 Lessons to be Learned The significance of different warnings issued by the EA appeared not to have been fully understood.
The upgrading of some flood warnings it is felt, was not as timely as they could have been, and some residents reportedly only received warnings as their properties were being flooded.
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8 Conclusions
The combined effects of the concurrent high spring tide and the storm surge generated by the weather system over the North Sea led to exceptionally high water levels along the east coast Humber Estuary, Rivers Ouse and Trent which resulted in overtopping of some coastal and flood defences.
It has not yet been possible to assign a return period to the event, there may have been amplification effects as the surge wave came down the coast and then moved up the estuary, in both cases becoming more significant. Also return periods on the coast are a function of both still water level and wave height, making a specific return period value a complicated scenario. However the EA are currently working on their coastal and water level model to determine a return period for this event.
Due to the scale and nature of the event and the speed it developed all the emergency services were fully stretched, as the flooding travelled down the coast and along the river. The event exceeded previous levels at the Hull barrier by a considerable margin.
The result was flooding of 231 residential and 69 commercial properties and extensive areas of farmland some 6000acres, and many minor roads affected by flood water, with damage estimated to the value of £13.4 million, and many people evacuated from their homes some by the council, other residents evacuated their properties which emergency services were unable to reach in time due to the extent and scale of the problems, the speed with which flooding occurred and by problems caused by flooded roads.
Due to the scale and the unforecastable nature of the event and the speed with which it developed, it was very difficult to know which areas would be affected. In some areas the flooding happened so quickly and in darkness that people were caught not knowing which way to go to escape the water as in some areas the water did not flow directly from the river. Some drainage systems were observed flowing backwards due to the sudden inflow of flood water.
Damage to agricultural premises and to the farmland itself was extensive, with some losses of livestock. The damage to the land itself is difficult to assess as it is dependent on the salinity of the flood waters, the soil type and the intended crops.
It has been observed that had the tidal surge occurred last winter when the land was saturated and watercourses at high levels due to a very wet year the situation would have been even worse, but following a relatively dry summer and autumn conditions were less critical.
In conclusion, the storm surge was the overriding factor in the flooding experienced on 5 December 2013. Surge analysis has shown that the surge occurred before the astronomical peak took place, the consequence of the earlier peak was that the flood event was not as severe as it could have been.
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The effects of timing were substantial and the two hour lag between the surge peak and the astronomical peak was responsible for reducing the peak tide levels by almost 0.4m in the Humber Estuary. The effects of a higher tide level of this magnitude would have been overtopping across a wider area and much more significant consequences across a wider area of the coastline.
What can be said with some certainty is that the tidal levels within the estuary were higher than at Bridlington and that the funneling effects of the estuary on constricting the storm surge and raising water levels was more significant in the estuary than along the coast.
The EA’s Flood Warning system needs investigation with a view to improving the quality of the information because particularly, of the emotional impact an event such as this has on peoples’ lives.
We also concluded that this event whilst out of the ordinary could occur again. It is not cost beneficial using current Treasury Rules to finance defences to withstand an event of this magnitude. However the council believes there is a case for reviewing the Treasury Rules, which currently favour urban over rural communities.
There is a government funded flood support scheme, offering a grant of up to £5,000 per flooded property. Known as the Repair and Renew Grant this is an initiative to assist property owners to increase their properties’ flood resilience.
The Council is administering the scheme in the East Riding, a cross departmental working group has been established which meets on a regular basis in order to co-ordinate, implement and administer the scheme.
The Council concluded that all agencies including the EA and IDBs worked effectively together with good communications and co-operation during the event and throughout the recovery.
The council is required to conclude whether each of the risk management authorities identified has exercised, or is proposing to exercise, their functions in response to the flood incident. Following the investigation it can be concluded that the flood risk management authorities have or are proposing to exercise their relevant functions appropriately.
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9 Recommendations
The investigation has identified a number of measures that could improve flood resilience and these are set out in the following recommendations:
9.1 Recommendation 1 The EA should consider carrying out a thorough review of their Flood Warning procedure, tidal warning and forecasting systems to identify possible improvements to the timeliness of warnings.
9.2 Recommendation 2 The EA should also be encouraged to progress their current update of the Humber Strategy as a matter of urgency; the council supports the EA in this.
9.3 Recommendation 3 The EA should consider launching a publicity campaign to inform the public of the significance of the Flood Warning procedure and of the warnings themselves, including the measures which people can take to safeguard themselves.
9.4 Recommendation 4 The EA should also consider making available all telemetry data and live tidal forecast analysis to Lead Local Flood Authorities through a web portal. The council should use their own monitoring systems to add value to information about tidal events to enable the most timely response to events.
9.5 Recommendation 5 The parish councils in all affected areas should consider preparing or reviewing and updating a Local Emergency Plan. The council’s Emergency Planning Team and the Flood Risk Management Team could offer advice and assistance.
9.6 Recommendation 6 As part of the parish council’s Local Emergency Plan all property owners in the affected areas should be encouraged to develop a property flood plan, to be implemented following any flood warning. Affected property owners should also be encouraged to sign up to the EA’s flood warning system for the most up to date information regarding flooding.
9.7 Recommendation 7 Property level protection and or flood resilience measures should be considered at vulnerable properties. This should be addressed by the Governments Help for Homeowners/Repair and Renew Grant. See Appendix 9 and 10.
9.8 Recommendation 8 Defra should consider carrying out a review of their methodology for economic assessment set out in national project appraisal guidance. This would enable flood risk management authorities to most effectively invest in critical flood risk infrastructure, for example along the entire Humber frontage where the appropriate design standard would be to provide a standard level of protection of 0.5% Annual Exceedance Probability (1 in 200 year) with an allowance for climate change over the design life of the asset.
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Useful Links and Contact Details:
Lead Local Flood Authority (01482) 887700 www.eastriding.gov.uk East Riding of Yorkshire Council County Hall Beverley [email protected] East Riding of Yorkshire HU17 9BA
Statutory Sewerage Undertaker (08451) 242424 www.yorkshirewater.co.uk Yorkshire Water Services Ltd Western House Halifax Road Bradford BD6 2SZ
Environment Agency General Enquiries: www.environment-agency.gov.uk Dales Area Office Coverdale House Amy 0870 850 6506 Johnson Way Clifton Moor (Mon-Fri, 8am -6pm) York YO30 4UZ Incident Hotline: 0800 807060 (24hrs) Internal Drainage Board (01302) 342055 [email protected] Reedness and Swinefleet Drainage Board Shires Group of IDB’s Denison House Hexthorpe Road South Yorkshire DN14 0BF Internal Drainage Board (01430) 430237 [email protected] Ouse and Humber Drainage Board 91 Bridgegate Howden East Riding of Yorkshire DN14 7JJ
Internal Drainage Board General Enquiries: [email protected] South Holderness Internal Drainage Board (01964) 630531 18 Market Place Patrington Emergency: East Riding of Yorkshire (07980) 864909 HU12 0RB
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Appendix 1: Indicative Flood Extents in the East Riding of Yorkshire
Figure 2: Indicative Tidal Flood Events
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Appendix 2: Properties Affected
Number of properties Where Flooding occurred affected External - Garden 27 External - Outbuilding(s) 10 Internal 263 Grand Total 300
Table 3: Properties Affected
Number of properties Location of Flooding affected Bridlington 44 Paull 42 Reedness 39 Hessle 35 North Ferriby 29 Yokefleet 25 Blacktoft 22 Kilnsea 22 Faxfleet 14 Old Goole 11 Skelton 6 Saltmarshe 3 Ulrome 3 Easington 2 Skipsea 2 Hornsea 1 Grand Total 300
Table 4: Properties Affected by Town (Residential and Commercial)
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Appendix 3: Flood and Weather Warnings
Flood Warnings issued by the Environment Agency Floodline:
Flood Alert, flooding is possible. Be prepared.
This Alert is issued when flooding is considered possible, and anyone at risk is advised to check their flood plan and flooding preparedness.
Flood Warning, flooding is expected. Immediate action required.
This Warning is issued when flooding is expected to happen, and anyone at risk is advised to implement their flood plan and prepare for flooding.
Severe Flood Warning, Severe flooding. Danger to life.
This is the highest level of warning and anyone at risk is advised to implement their flood plan, and the emergency services will mobilise and evacuation plans are implemented.
Severe Flood WarningSevere flooding. Danger to life.
Flood WarningFlooding is expected. Immediate action required
Flood Alert Flooding is possible. Be prepared.
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Examples of the Flood Guidance Statements issued in the early December 2013
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Appendix 4: Photographs
Photographss of the after effects of the flooding. Some taken by ERYC staff and some aerial photographs taken by the EA on 6 December 2013.
As the event occurred during the evening in darkness very few photographs of the actual event are available.
These show the effects on the coast as well as along the river.
Photograph 4: Hornsea Promenade on the morning of 6 December 2013
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Photograph 5: Ulrome beach showing private sea defence damaged by the surge
Photograph 6: Erosion following damage to private defence at Ulrome
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Photograph 7: Kilnsea on 6 December 2013
Photograph 8: Debris on the road at Kilnsea
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Photograph 9: Caravans at Kilnsea
Photograph 10: Damaged Caravans at Kilnsea
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Photograph 11: Flood water trapped behind the defences at Kinsea
Photograph 12: Welwick area on 6 December 2013
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Photograph 13: Hessle Foreshore on 6 December 2013
Photograph 14: Overpumping to assist land drainage system to clear flood waters, at Crabley where the IDB pump had been inundated and had failed.
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Photograph 15: Saltmarshe
Photograph 16: Damage to river embankment near Faxfleet
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Photograph 17: ERYC mobile pump in Blacktoft
Photograph 18: Embankment damage at Blacktoft
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Photograph 19: Flood water behind the embankment and debris washed up by the flood
Photograph 20: Looking inland from embankment near Blacktoft
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Photograph 21: Yokefleet on 6 December 2013
Photograph 22: Blacktoft and South Bank, on 6 December 2013
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Photograph 23: Looking east along the Humber from Goole
Photograph 24: Damage to bankside at Reedness drain
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Photograph 25: Damage to bankside at Reedness drain outfall
Photograph 26: Damage to bankside at Reedness drain
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Photograph 27: Tide mark where embankment was overtopped at Reedness
Photograph 28: Stranded car near Yokefleet
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Appendix 5: Data Analysis by Capita
Flood Defence Review and Analysis
Surge Analysis
Wind Speed and Wave Analysis
Flood Defence Asset Review and Management
Flood Warning Review
Assessment of the Flood Damage
For further information about this data please contact:
David J Waudby Head of Infrastructures and Facilities, East Riding of Yorkshire Council
Extract of the report from the Data Analysis carried out by Capita
• Flood Defence Review • Surge Analysis • Wind Speed and Wave Analysis • Flood Warning Review • Assessment of the Flood Damage
The full report is available on request
Contact David J Waudby Head of Infrastructure and Facilities
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Rationale for analysis and outcomes
Flood Defence Review The Environment Agency holds a significant amount of information on flood defences in its National Flood and Coastal Defence Database (NFCDD). The NFCDD dataset, and the Asset Information Management System (AIMS) dataset that it is being transferred to, includes geographical information on asset location in MapInfo format, and includes information on defence heights.
A review of the NFCDD dataset and particularly the defence height information enabled a comparison to be made against observed tide level information within the study area. This will identify where it would have been expected that flooding would have taken place and, with comparison to the flood extents from the event, it will allow the identification of areas that flooded but which would not have been expected to do so based on flood defence levels. These areas would be indicative of areas where there are previously unknown ‘low’ spots or areas where the source of flooding was perhaps not directly related to overtopping but could instead indicate minor breach, piping, or an area where tidal levels affected flooding from other sources.
Surge Data The British Oceanographic Data Centre (BODC), operated by the National Oceanography Centre (NOC) (formerly the Proudman Oceanographic Laboratory, POL) holds quality checked tide gauge data from 44 locations around the UK, including Immingham and Whitby. This dataset is particularly useful as it identifies not only the observed water level but also the forecast sea level. The difference between these two records, referred to as the residual, reflects the degree of surge at each time step of the record.
Analysis of the residual shows the timing of the surge relative to the timing of the forecast tide and identifies when and how severe the surge was. It also allows an assessment of the potential consequences in terms of a higher or lower peak water level had the surge timing been slightly different.
Wind Speed Tidal flooding is typically caused by particularly high spring tide levels. There may or may not be an influence from a surge caused by a low pressure weather system (such as in this case). A final factor that can be the cause of overtopping when water levels are close to the crest height of defences, is the height of waves generated by storm winds or of swells generated by distant storms. The forecast (astronomical) tide and surge elements of the December 2013 event can be analysed by a review of the BOTC tide level and residual data, however, this analysis aims to provide some analysis and narrative of the potential influence that wind driven waves had on the flooding observed.
The height of wind waves and how they can vary is relatively well understood and there is a wide range of literature that allows the height of wind waves to be forecast/estimated using information on wind duration (hours), wind speed (m/s) and the available distance over water that the wind can blow (fetch, km) which is a function of the wind direction. Essentially, the longer the wind is blowing, the faster the wind speed and the greater the fetch then the higher the wind wave height.
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Wind direction and speed information was available for a range of locations within and around the East Riding and analysis of that data allowed an estimate to be made of wind wave heights along the coast and within the Estuary. In conjunction with the information on tide levels, surge heights and defence heights, this will complete the picture of what specific element of coastal flooding was responsible for the flooding along the coast.
Asset Management The Environment Agency’s NFCDD and AIMS datasets contains information on:
• Defence Type • Condition • Ownership • Maintenance responsibility • Design standard and • Standard of protection provided by the defence
The aim of the analysis of the above is to make available a visual understanding of where defences are located, what type they are and condition they are in, who owns them and has responsibility for their maintenance. The information presented may highlight potential future maintenance concerns and areas where it would be beneficial for the relevant flood risk management authorities to address potential weaknesses, shortcomings and uncertainties in the defences in the locations where flooding was observed.
Flood Warning The Environment Agency provides flood warnings for tidal flooding along the coastline and these are based on forecast tidal levels and forecasts of the impacts of storms on tidal levels. A large number of warnings were issued across the area but as the impacts were not consistent neither were the warnings. The aim of the review of flood warnings was to identify when they were issued relative to the height and state of the tide in key locations. The analysis will allow an assessment of the effectiveness of the warnings and will enable recommendations to be made with regard to reviewing the way forecasts are made or warnings issued to potentially improve their effectiveness.
Damage Estimation A damage estimate was undertaken using the guidance in the latest edition of the Multi-Coloured Manual (MCM) and Multi-Coloured Handbook (MCH), published by the Flood Hazard Research Centre, the Environment Agency and Defra. An overview assessment was undertaken to provide a first approximation of damages using the number of properties shown to be affected by the December 2013 flood extent.
The outcome of this element was identification of the properties affected and the economic damages to dwellings and business by sector (retail, office, distribution etc), an assessment of the economic damages to vehicles and an estimate of the intangible costs on health, emergency services costs and temporary or alternative accommodation. A comparison of the above factors relative to a ‘no defences’ scenario will coarsely identify the benefit afforded the region through the presence of the defences and their continued maintenance.
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Flood Defence Review
Introduction As part of the S19 Investigation into the tidal surge experienced along the Yorkshire coast on 5 December 2013, a review of flood defence heights relative to observed water levels and flooding has been undertaken. The following presents the methodology used and results of this analysis.
Data Review A dataset was made available from East Riding of Yorkshire Council (ERYC) that depicts the extent of flooding from 5 December 2013 tidal surge event. The flood extents have been based on aerial photography taken shortly after the flood event had occurred. It is important to bear in mind that, as these are based on aerial photographs, they can only be a best estimate of the flood extent and that the extent of flooding in some areas could have been underestimated.
The data used to identify and assess the flood defences in this study has been provided by the Environment Agency and forms part of its Asset Information Management System (AIMS) dataset. Both fluvial and coastal defences are present in this dataset, with coastal defences classified as embankments, sea walls, cliffs and other objects relating to high ground.
Tidal stage data taken at 15 minute intervals was provided by the Environment Agency (EA) for a number of locations within the study area. In total there are 11 tidal gauges for which data has been provided.
Comparison of Tidal Stage - Humber Estuary 8
6
4
Skeffling PS 2 Goole Immingham
Tidal Stage (mAOD) 0
-2
-4 Data/Time
Figure 3: Comparison of Tidal Stage at Skeffling PS, Google and Immingham
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Methodology and Approach The main objective of the review is to first pinpoint areas where, based on surveyed elevations and observed tidal levels, overtopping of defences would have been expected. These areas have subsequently been compared to the anecdotal flood extent provided for the December 2013 event.
Results and Observations Figures 4, 5 and 6 at the end of this technical note present the locations in which flooding could have been expected based on a comparison between the surveyed points analysed and the interpolated tidal stage.
Conclusions In general the locations of flooding forecast by the analysis of the defences appear to match well with the anecdotal flood extents used in this analysis. The defence height review has highlighted the key areas where flooding has occurred and provides an indication of the crest heights in these locations. Using these heights it may be possible to draw some conclusions as to the contribution that the storm surge and wind driven waves may have had on the severity of flooding experienced on 5 December 2013.
There are some areas where defence heights imply that flooding should have been observed but where none is indicated in the dataset provided by EYRC. As indicated earlier, this may be because flooding was no longer present at the time of the aerial photograph or because the flooding was not as high as gauged levels elsewhere would imply. The way the surge propagated up the estuary led to higher water levels at certain locations in relation to others. It is noted that there are areas, particularly along the coastline between Hessle and Kingston upon Hull where this is observed.
Limitations The limitations of this analysis relate to the data available.
As indicated above the survey points refer to a number of different features and many cannot be attributable to a defence crest. Filtering of many points was undertaken, however there may remain some points that represent points lower than the defence crest. There could therefore be some points presented in Figures 4 to 6 that suggest flooding should occur when this would not be the case.
A second limitation, as indicated above, relates to the digitised flood extent. These were digitised from aerial photography taken after the flood event and may not capture the full extent of the flood event in all locations. They should therefore be considered an estimation only of the extent of flooding. There will be scope for areas to have been underestimated as a result.
There also limitation in the application of an interpolated tidal stage grid. As discussed previously, the tidal stage grid used within this analysis has been based on 10 gauged locations along the coast and Humber. The spacing of these locations is not consistent and a number of interpolated points were required. Whilst the interpolated stage grid will be a good generalisation of the data it may not reflect local bathymetry and subsequently peak water levels in some locations.
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CES\FM009 Figure 4: Locations where Tidal Elevation exceeded Surveyed Elevation (Goole to Broomfleet) Page | 71 Flood Investigation Report - Tidal Surge Flooding Events on 5 December 2013
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Figure 5: Locations where Tidal Elevation exceeded Surveyed Elevation (Broomfleet to Hull Barrier)
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Figure 6: Locations where Tidal Elevation exceeded Surveyed Elevation (Hull Barrier to Easington) CES\FM009 Page | 75 Flood Investigation Report - Tidal Surge Flooding Events on 5 December 2013
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Surge Analysis
Introduction An analysis of the storm surge height relative to the forecast astronomical tide level has been performed as part of the S19 Investigation into the tidal flooding experienced across the East Riding of Yorkshire coast on 5 December 2013. The following technical note presents the methodology and results of this analysis. The results of this analysis provide an indication of the contribution to flooding that the storm surge had on the observed flooding in December 2013 as well as the contribution that the storm surge could have had on the observed flooding had it been timed differently.
Methodology and Approach A technical appendix has been provided along with the original document, which presents further details on the results of this study. The following section presents an overview of the methodology and approach and summarises the outcomes.
The surge analysis can be split into two parts. The first part of the analyses looked at the contribution to coastal flooding that the surge played during 5 December 2013 event. This analysis made use of surge height data provided by the Environment Agency’s Flood Hydrology Fact Sheet 13: The tidal surge of 5 December 2013 (v2). The fact sheet provides forecast high tide levels compared against observed tidal levels for a number of sites across the North East coast from Aberdeen to Goole. The fact sheet provides an indication of the difference between observed and forecast peak water levels, known as the residual, and which indicates the height of the surge at the time of the peak tide. Surge heights for 5 key tidal gauges within the S19 investigation area are provided and these were:
• Goole • Blacktoft • Hull Barrier • Immingham • Bridlington
Using the forecast astronomical high tide at each of these locations it was possible to interpolate a forecast high tide level across the investigation area from Goole to Bridlington. This forecast high tide level was then compared against defence heights obtained from a defence survey that took place post-flood, the aim of which was to provide an indication of whether any overtopping might have been expected had no surge been present. The surge heights were then compared against the approximated range of defence crests heights from the defence review to provide an indication as to the contribution that the storm surge had on flooding.
Table 5 below presents the surge heights calculated by the Environment Agency for each of the 5 locations.
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Peak Tidal Astronomic Tidal Gauge Stage Time of Tidal Peak Forecast High Surge (m) 05/12/2013 Tide (mAOD) Goole 6.04 05/12/2013 19:45 4.67 1.37 Blacktoft 6.01 05/12/2013 19:30 4.48 1.53 Hull Barrier 5.81 05/12/2013 19:15 3.88 1.93 Immingham 5.31 05/12/2013 19:00 3.61 1.70 Bridlington 4.56 05/12/2013 17:45 2.80 1.76
Table 5: Surge Heights at 5 gauged locations
The second part of the analyses looked at the implications on the severity of flooding had the peak storm surge been timed differently. The EA’s Flood Hydrology Fact Sheet makes it very clear that these surge heights presented were not the peak surge experienced on 5 December 2013 but the surge height at the time of the peak observed tide at these locations. Tidal stage and residuals plots obtained from the British Oceanographic Data Centre (BODC) were reviewed to understand the timing of the surge relative to the time of the high tide and to assess what might have happened had the surge peak coincided with the forecast astronomical tide peak.
Plot of Tide Level Against Residual (Surge) -
6 Immingham Stage (mAOD) 5 Residual 4 Predicted Astronomic 3 Tide 2
1
0 -1
TidalStage (mAOD) -2 -3
-4
-5 Date/Time
Figure 7: Plot of Tide Level against Surge at Immingham
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Difference in Peak Surge and Lag Between Surge Residuals Donor Surge At Observed Peak Surge (m) Surge at time of Peak and Observed Site Tidal Peak (m) Observed Tidal Tidal Peak (Hours) peak(m) Immingham 1.97 1.587 0.38 +1.75 Whitby 1.63 1.48 0.16 +1.5
Table 6: Surge Analysis at Immingham and Whitby
As shown in Table 6 above, and indicated in Figure 7 on the previous page, both gauges experienced peak surges before the forecast astronomical high tide had passed. In both cases the time between the peak observed tide and the tidal surge peak was similar (1.5 hours and 1.75 hours). In addition the time between the peak tidal surge and the forecast astronomic tidal peak was 1.75 hours at Whitby and 2 hours at Immingham.
Surge analysis has shown that the surge occurred before the astronomical peak took place. The earlier timing of the surge peak resulted in the observed peak occurring approximately 15 minutes earlier than the astronomical peak was forecast. The consequence of the earlier peak was that the flood event was not as severe as it could have been.
The Table below presents a comparison of the astronomical forecast high tide, the observed peak tidal stage and the potential tidal stage that could have resulted had the storm surge been timed differently against the defence crest heights calculated as part of the flood defence review.
Highest Highest Astronomi Peak Tidal Bank Defence Estimated Potential Estimated c Forecast Stage Location / Heights Depth over Tidal Stage Depth over High Tide 05/12/201 Coast (mAOD) Defence (mAOD) Defence (mAOD) 3 (observed) (potential)
Goole Right 6.4 - 6.7 4.67 6.04 NF 6.42 0.02 Sand Hall / Sand Left 5.6 - 6.7 4.67 6.04 0.44 6.42 0.82 Hall Farm Yokefleet - Left 5.6 - 6.7 4.48 6.01 0.41 6.39 0.79 Blacktoft Reedmires Right 5.6 - 6.7 4.48 6.01 0.41 6.39 0.79 Faxfleet Left 5.4 - 7.2 4.38 6.2 0.8 6.36 0.96 Broomfleet Left 5.4 - 7.2 4.38 6.2 0.8 6.36 0.96 North Ferriby Left 5.5 - 6.7 4.28 6.07 0.57 6.33 0.83 Humber Bridge Left 5.4 - 5.7 4.18 6.05 0.65 6.29 0.89 Kingston Upon Hull Left 4.8 - 6.2 3.88 5.81 1.01 6.19 1.39 Paull North Left 5.6-7.6 3.79 5.7 0.1 6.03 0.43 Paull East Left 5.5 - 6 3.79 5.7 0.2 6.03 0.53 Paull South Left 5.8 - 6 3.79 5.7 NF 6.03 0.13 Cherry Cobb Sands Left 5.9 - 6 3.61 5.31 NF 5.69 NF Sunk Island Sands Left 5.8 - 6 3.61 5.31 NF 5.69 NF Kilnsea Coast 6.2 - 6.5 3.32 5.144 NF 5.35 NF
Table 7: Comparison of Defence Crests against Astronomical Forecast High Tide, Observed Peak Tide and Potential Peak Tide
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In conclusion, the storm surge was the overriding factor in the flooding experienced on 5 December 2013. Furthermore, the effects of timing were substantial and the two hour lag between the surge peak and the astronomical peak was responsible for reducing the peak tide levels by almost 0.4m in the Humber Estuary. The effects of a higher tide level of this magnitude would have been overtopping across a wider area and much more significant consequences across a wider area of the coastline.
Wind Speed and Wave Analysis
Introduction This analysis aims to study wind data relating to 5 December 2013 with a view to estimating wave heights across a number of key sites, particularly relating to those where flooding was observed. The results of this analysis should provide some idea as to the contribution that wave heights may have had to the flooding that occurred.
Methodology and Approach A technical appendix has been provided along with this document, which presents further details on the results of this study. The following section presents an overview of the methodology and approach and summarises the outcomes.
A number of key sites were selected for wave height analysis. These sites were selected with consideration to the areas shown to flood during 5 December 2013 event, which were themselves derived from digitised aerial photographs of flooding provided to the Council by the Environment Agency. In total 9 sites were selected for analysis.
Wave heights estimates utilised the Groen and Dorrestein Manual Wave Forecasting Diagram, below. The method for estimating wave heights according to this forecasting model requires the user to obtain an estimation of the wind speed (m/s), Wind duration (hours) and Fetch (km).
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Figure 8: Manual Wave Forecasting Diagram
The aim of the analysis was to assess the potential range of wave heights deemed possible from the weather data collected. (See also Appendix 6 Wind Speed and Direction Map)
Two datasets were analysed from the available wind speed/direction information. The first, represented recordings taken at principal hours of the day 0,6,12 and 18 and is presented in Appendix A. This dataset formed the basis of the wave height estimations over the course of the 5th and the preceding week, looking at an average wind speed for each day and varying wind directions taken at the principal hours discussed. The second, represented hourly data from the weather stations which provided some scope for further assessment into the timing of the wave heights relative to the peak tide. This data is presented in more detail in Appendix B.
Finally the analysis has looked at hourly data for wind speed and wind direction on 5 December 2013. Figures 9-12 present graphical outputs from this dataset showing the average wind speed against the hourly plot. It also highlights the time of peak tide at Immingham and the wind directions recorded throughout the day. This analysis has sought to assess whether a higher wave height estimate could have been derived based on the more detailed dataset and also whether the timing of the wind speed/directions could have played a significant factor. This analysis was applied at 4 of the key sites namely; Humber Bridge, Paull, Kilnsea and Bridlington.
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Results and Observations The results of this analysis are presented in Table 8 and Table 9 below, and at the end of this summary.
Table 8 presents the results from the first analyses looking at 5 December 2013 event in isolation. Table 9 presents the results from the second analyses looking at the precedent conditions on 29 and 30 November 2013. The results clearly suggest that there was a greater potential maximum wave heights achieved on 5 December 2013, which suggests that in this instance wind speed had a greater effect on the potential wave heights than the duration.
It is important to note that the wind directions experienced on 5 December 2013 had a considerable effect on the wave heights experienced along the coast and within the Humber Estuary. In general the predominant wind direction was north westerly (i.e. from the North West). A Met Office report into the Winter Storm of December 2013 noted that north westerly winds were responsible for blowing the surge down the east coast of Britain. Included with the Appendix 6 is a wind direction figure which demonstrates the range of wind directions experienced on 5 December 2013.
The predominant wind direction relative to the coast was blowing offshore and as a result areas such as Hornsea and Skipsea are not estimated to have experienced significant wind driven waves during 5 December 2013 flood event. Other coastal areas such as Bridlington and Kilnsea are estimated to have experienced waves driven by the strong winds, however, at Bridlington the fetch is limited to shorter sections of the coast line and at Kilnsea the waves are attributable to wind driven waves across the Humber Estuary and not from the North Sea.
The wave height estimates show that the largest wave heights were experienced at the mouth of the Humber Estuary. This is attributable largely to the widening of the channel and the subsequent increase in available fetch and also the direction of the estuary relative to the wind direction. In general the estimated wave heights are shown to decrease up the Humber Estuary to Faxfleet.
05/12/2013
Wave Heights (m) Site Easting Northing Minimum Maximum Skeffling 533434 418595 0.48 0.90 Kilnsea 540775 416595 0.50 1.00 Bridlington 518697 466614 0.24 0.32 Skipsea 517851 456067 0.00 0.00 Hornsea 520976 447693 0.00 0.00 Paull 517849 424682 0.35 0.96 Humber Bridge 502633 425299 0.27 0.88 North Ferriby 495983 424680 0.35 0.65 Faxfleet 488623 426357 0.26 0.56
Table 8: Potential Minimum and Maximum Wave Height Estimation for 5 December 2013
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29/11/2013 - 30/11/2013 48 Hour Wind Duration
Wave Heights (m) Site Easting Northing Minimum Maximum Skeffling 533434 418595 0.39 0.56 Kilnsea 540775 416595 0.44 0.68 Bridlington 518697 466614 0.14 0.26 Skipsea 517851 456067 0.00 0.00 Hornsea 520976 447693 0.00 0.00 Paull 517849 424682 0.23 0.58 Humber Bridge 502633 425299 0.38 0.38 North Ferriby 495983 424680 0.25 0.34 Faxfleet 488623 426357 0.00 0.15
Table 9: Potential Minimum and Maximum Wave Height Estimation for 29 – 30 November 2013
These results confirm that potential wave heights along the coast at Bridlington, Skipsea, Hornsea and Kilnsea were less substantial than those within the Estuary and it also indicates that wave heights within the estuary tend to increase towards the mouth of the estuary. It should be noted that a forecast of low wind driven wave height does not mean that there were no waves or swell, only that for the period of analysis and based on the wind direction, available fetch and wind speed there would have been little contribution from wind towards the further generation of waves. Waves and swell may still have been present from weather events.
A review of the hourly wind speed and direction has provided further information pertinent to the contribution that the wind may have had to the flooding experienced during the tidal flood event. The graphs presented in Figures 9 – 12 clearly show that in the wind speed is reduced below the average by 16:00/17:00 across the study area. This would essentially suggest that the wave heights would have been receding as the tide began to rise. However, as a rule of thumb it is suggested that as the wind speed reduces below the required level to maintain a given wave height the estimated height will reduce by 25% every 12 hours and so the reduction is not thought to be significant.
The graphs also show clear periods between the hours of 09:00 and 17:00 where the wind speed is above the average used in the calculations presented in Appendix A. This led to further analysis at four sites across the study area to assess whether the increased wind speeds over this period could have provided increased wave heights above the estimate presented in Table 8. For Bridlington it is noted that the average wind direction over the course of this period was 290o which is in an offshore direction thus no wind driven waves are forecast. At Paull and Humber Bridge the average wind direction calculated from the contributing weather stations is calculated to be 270o at Leconfield and Humberside and 260o at Donna Nook. In each case the available fetch for this period is well below the maximum calculated and as such no increased wave heights are estimated from the hourly data.
The exception to this is at Kilnsea where the average wind direction calculated from Donna Nook is 260o which corresponds to the maximum achievable fetch for the site. In this instance, the maximum achievable wave heights can be recalculated to be 1.35m, 0.35m greater than the original estimate.
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Limitations There are a number of limitations associated with these estimates, mainly in respect of the data available, and whilst they don’t alter the conclusions on the relative importance of the contribution that waves may have had in the event they should be borne in mind.
Initially, the wind speed data available for each day is an average wind speed over each 24 hour period. Consequently, shorter periods of higher wind speed will not be represented within the data and this lack of detail may mean that the estimates made are an underestimate.
It will also be noted that the wind data is derived from four land-based weather stations in the local area. Wind speed and direction appear relatively consistent at a regional scale, however, there may be local variations and differences caused by the local topography and differences in elevation for example, which may mean that local conditions at some of these sites could have been different. Sites along the east coast, particularly Kilnsea, Hornsea and Skipsea, may have experienced stronger winds by virtue of their position on an exposed coastline. It’s possible therefore that the estimates at these coastal sites may be underestimated.
Finally, it should be noted that the estimate of wind-driven wave heights does not then take into account the effect of those waves reaching shore. It is known that as waves reach shallower water depths that the wave period (distance between waves) can shorten as the wave speed reduces and that wave height can consequently increase. It would be expected therefore that the waves experienced on shore could have potentially been significantly higher.
Following the analyses presented in the Surge analysis and Flood Defence review it is possible to further compare the contribution that wave heights may have had on the flooding experienced on 5 December 2013. The surge analysis has found that in general the surge heights greatly surpassed the required levels for overtopping of the defences to have occurred. This is true in particular for areas such as Faxfleet. As such, it is difficult to quantify the relative contribution of the wave heights in the estuary to the flooding experienced as tidal heights were already very high due to the significant storm surge. What can be said is that in the event that 1.00m waves were experienced in the estuary for any period of time, this could well have had an additional worsening effect on the extent and severity of flooding
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Figure 9: Hourly Wind Data at Bridlington 05/12/2013 CES\FM009 Page | 85 Flood Investigation Report - Tidal Surge Flooding Events on 5 December 2013
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Figure 10: Hourly Wind Data at Donna Nook 05/12/2013 CES\FM009 Page | 87 Flood Investigation Report - Tidal Surge Flooding Events on 5 December 2013
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Figure 11: Hourly Wind Data at Humberside 05/12/2013
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Figure 12: Hourly Wind Data at Leconfield 05/12/2013 CES\FM009 Page | 91 Flood Investigation Report - Tidal Surge Flooding Events on 5 December 2013
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Weather Online Data
Graphs Location (See 'Map' Site Tab) Wind Speed Wind Direction
approximately 7 Donna Nook miles to the south east of Grimsby
approximately 20 Bridlington miles north of Hull on the coast
Figure 13: Weather Online Data CES\FM009 Page | 93 Flood Investigation Report - Tidal Surge Flooding Events on 5 December 2013
Weather Online Data
Location (See 'Map' Graphs Site
Tab) Wind Speed Wind Direction
Humberside Near Scunthorpe
Leconfield North of Hull
Figure 14: Weather Online Data CES\FM009 Page | 94 Flood Investigation Report - Tidal Surge Flooding Events on 5 December 2013
Flood Warning Review
Introduction Flood Warnings are a vital tool used by the Environment Agency (EA) to warn communities of forthcoming flooding affecting certain areas. EA Flood Warnings fall under three classification based on the severity of flooding expected. The three levels of warning are:
• Flood Alert – Flooding is possible. Be prepared; • Flood Warning – Flooding is expected. Immediate action required; and • Severe Flood Warning – Severe flooding. Danger to life.
Flood warnings are issued when certain water levels are forecast at tidal and river gauges – this measurement is known as the Threshold Level. Threshold levels may be in metres (i.e. the height of water above or below the gauge datum) or in metres above ordnance datum (i.e. the elevation or altitude of water). As flood warnings are issued, various operational procedures are put into action – for example sand bags may be dispensed, a flood gate could be closed to protect an area from flooding, or the fire brigade may be called to an area to help pump flood water away from properties. It is crucial therefore that the threshold level used by the EA is suitable for the area it is used to warn. Suitable thresholds should be set at a level that allows enough time for communities to be warned and for the procedures used to manage flooding to be effectively carried out. Thresholds should not be so low that communities are needlessly warned of flooding and not so high that ample time is unavailable prior to flooding affecting a community.
The storm surge and high tides of 5 and 6 December 2013 caused significant flooding in areas along the East Coast of England and to communities on the River Humber and the Humber Estuary.
In total 47 flood alerts or flood warnings (both normal level and severe level) were issued to 24 Flood Warning Areas (FWAs) during 5 December 2013 along the East Coast, north of the Humber Estuary and along both left and right banks of the Estuary itself from its mouth at Spurn Point (TA 39900 10890) upstream as far as Skelton (SE 76479 25835) and Howden Dyke (SE 76021 26760).
Details on the areas warned or alerted, the type and time of warning, and the threshold level and gauge location used to warn the FWAs are provided in Table 10 (below). Figure 15 shows the location of each of the 24 FWAs to which alerts or warnings were issued during 5 December 2013.
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CES\FM009 Page | 96 Flood Investigation Report - Tidal Surge Flooding Events on 5 December 2013 Target Area Warning / Warning / Alert Area Type Day Lowest Trigger Code Alert Sent 03/12/2013 4.97 Weeton Bank, Weeton Fields, 122WAT957 Humber Estuary from Spurn Point to Winestead Outfall Flood Alert Tuesday 15:37:57 Skeffling Clough Coast from Fairlight to Dungeness including the Tidal 04/12/2013 064WAC306 Flood Alert Wednesday Rother 17:34:12 04/12/2013 122WAC954 North Sea Coast at Bridlington Flood Alert Wednesday 4.29 Brid South Pier 17:40:47 04/12/2013 122WAC955 North Sea Coast at Hornsea Flood Alert Wednesday 4.90 Hornsea N Promenade St1 17:53:32 04/12/2013 122WAT961 Humber Estuary from Lords Clough to Hessle Haven Flood Alert Wednesday 5.67 West St Andrews Quay 18:02:06 04/12/2013 122WAC956 North Sea Coast at Withernsea, Easington and Kilnsea Flood Alert Wednesday 4.0 Spurn Road 18:03:36 04/12/2013 122WAT963 Humber Estuary from Faxfleet to Saltmarshe Flood Alert Wednesday 5.62 Blacktoft/Sparrowcroft lane 18:07:53 04/12/2013 122WAT962 Humber Estuary from Hessle Haven to Faxfleet Flood Alert Wednesday 4.97 East Clough 18:11:36 05/12/2013 122FWC002 North Sea Coast at Bridlington - South Pier Flood Warning Thursday 3.79 Harbour South 08:10:22 North Sea Coast at Bridlington - Harbour Road and Floral 05/12/2013 122FWC001 Flood Warning Thursday 3.79 Harbour North Pavilion 08:20:11 05/12/2013 122FWC007 North Sea Coast at Easington and Kilnsea Flood Warning Thursday 3.80 Southfield Farm (Coast) 08:27:51 North Bank of the Humber Estuary at Paull and Paull 05/12/2013 122FWT017 Flood Warning Thursday 5.68 Little Humber Holme Sands 10:46:01 North Bank of the Humber Estuary from Kilnsea to 05/12/2013 122FWT011 Flood Warning Thursday 4.97 Weeton, Skeffling Skeffling and Weeton 11:05:06 North Bank of the Humber Estuary at Broomfleet, Faxfleet 05/12/2013 122FWT038 Flood Warning Thursday 5.56 Broomfleet Foreshore and Blacktoft 11:28:42 05/12/2013 122FWT035 North Bank of the Humber Estuary at Brough Flood Warning Thursday 5.53 Brough 11:36:07 05/12/2013 122FWT034 North Bank of the Humber Estuary at North Ferriby Flood Warning Thursday 5.29 North Ferriby 11:47:48 05/12/2013 122FWT029 North Bank of the Humber Estuary at Hessle Flood Warning Thursday 4.72 Hessle Haven 11:52:37 05/12/2013 122FWT028 North Bank of the Humber Estuary at Hessle Haven Flood Warning Thursday 5.12 Cliff Road Hessle Haven 11:52:38 North Bank of the River Ouse at Saltmarshe, Sand Hall, 05/12/2013 122FWT040 Flood Warning Thursday 3.70 Church St, Whitby Lifeboat station Skelton and Kilpin Pike 11:59:36 North Bank of the River Ouse at Saltmarshe, Sand Hall, 05/12/2013 122FWT040 Flood Warning Thursday 3.70 Church St, Whitby Lifeboat station Skelton and Kilpin Pike 16:01:14 North Bank of the Humber Estuary at Broomfleet, Faxfleet 05/12/2013 122FWT038 Flood Warning Thursday 5.56 Broomfleet Foreshore and Blacktoft 16:13:23 05/12/2013 122FWT035 North Bank of the Humber Estuary at Brough Flood Warning Thursday 5.53 Brough 16:23:22 05/12/2013 122FWT034 North Bank of the Humber Estuary at North Ferriby Flood Warning Thursday 5.29 North Ferriby 16:32:37 05/12/2013 122FWT029 North Bank of the Humber Estuary at Hessle Flood Warning Thursday 4.72 Hessle Haven 16:40:13 05/12/2013 122FWT028 North Bank of the Humber Estuary at Hessle Haven Flood Warning Thursday 5.12 Cliff Road Hessle Haven 16:49:34 North Bank of the Humber Estuary from Kilnsea to 05/12/2013 122FWT011 Flood Warning Thursday 4.97 Weeton, Skeffling Skeffling and Weeton 16:59:19 North Bank of the Humber Estuary at Paull and Paull 05/12/2013 122FWT017 Flood Warning Thursday 5.68 Little Humber Holme Sands 17:13:17 05/12/2013 122FWC007 North Sea Coast at Easington and Kilnsea Flood Warning Thursday 3.80 Southfield Farm (Coast) 17:20:01 05/12/2013 122FWC002 North Sea Coast at Bridlington - South Pier Flood Warning Thursday 3.79 Harbour South 17:22:30 North Sea Coast at Bridlington - Harbour Road and Floral 05/12/2013 122FWC001 Flood Warning Thursday 3.79 Harbour North Pavilion 17:27:56 North Bank of the Humber Estuary at Paull and Paull 05/12/2013 122FWT017 Flood Warning Thursday 5.68 Little Humber Holme Sands 18:05:36 05/12/2013 122FWT021 North Bank of the Humber Estuary in the east of Hull Flood Warning Thursday 5.78 Victoria Dock Village1 & 3 18:09:26 05/12/2013 122FWT024 North Bank of the Humber Estuary in the west of Hull Flood Warning Thursday 5.72 St Andrews Quay, Freightliner Road 18:15:01 05/12/2013 122FWT035 North Bank of the Humber Estuary at Brough Flood Warning Thursday 5.53 Brough 18:18:42 05/12/2013 122FWC005 North Sea Coast at Tunstall Flood Warning Thursday 7.96 Tunstall 18:19:09 05/12/2013 122FWC008 North Sea Coast at Spurn Point Flood Warning Thursday 6.70 Spurn Point 18:25:12 05/12/2013 122FWC007 North Sea Coast at Easington and Kilnsea Severe Flood Warning Thursday 18:45:14 05/12/2013 122FWT029 North Bank of the Humber Estuary at Hessle Severe Flood Warning Thursday 18:47:05 05/12/2013 122FWT021 North Bank of the Humber Estuary in the east of Hull Severe Flood Warning Thursday 18:50:21 North Bank of the Humber Estuary at Broomfleet, Faxfleet 05/12/2013 122FWT038 Severe Flood Warning Thursday and Blacktoft 18:52:28 05/12/2013 122FWT024 North Bank of the Humber Estuary in the west of Hull Severe Flood Warning Thursday 18:53:49 05/12/2013 122FWT028 North Bank of the Humber Estuary at Hessle Haven Severe Flood Warning Thursday 18:56:44 05/12/2013 122WAF947 Tidal River Ouse Flood Alert Thursday 5.0 Selby Westmill (Fluvial Alert) 21:12:05 06/12/2013 122WAC956 North Sea Coast at Withernsea, Easington and Kilnsea Flood Alert Friday 4.0 Spurn Road 15:22:51 06/12/2013 122FWC007 North Sea Coast at Easington and Kilnsea Flood Warning Friday 3.80 Southfield Farm (Coast) 15:32:17 06/12/2013 4.97 Weeton Bank, Weeton Fields, 122WAT957 Humber Estuary from Spurn Point to Winestead Outfall Flood Alert Friday 15:57:07 Skeffling Clough 06/12/2013 122WAF947 Tidal River Ouse Flood Alert Friday 5.0 Selby Westmill (Fluvial Alert) 17:22:50
Table 10: Details of Flood Warnings and Alerts issued during 3 and 6 December 2013
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Aims and Objectives The aim of this review, which has considered the timing of flood warnings issued relative to the speed of onset of the surge and the rise of water levels, is to assess the effectiveness of the warnings and trigger levels and will enable any necessary recommendations to be made within the Section 19 Report for action by the Environment Agency and its partners.
This work has sought to achieve the following:
• Map the location and timing of flood warnings issued during the storm surge of 5 December 2013 • Assess the timing of flood warnings issued relative to maximum gauge levels being reached at gauges relevant to the areas warned • Map the location of flooded areas that were not warned • Investigate the possible reasons for flood warnings not being issued to areas found to have flooded during the storm surge
Data and Approach This investigation has made use of the following sources of information during a desk-based study:
• 1:25 000 and 1:250 000 scale Ordnance Survey (OS) Mapping • Location of EA Flood Warning Areas • Information of the timings and flood level thresholds of issued flood warnings and alerts from the EA and • Stage data (water level in metres) from gauges on the Humber Estuary provided by the EA
Limitations There is uncertainty over how the thresholds used by the EA to warn areas of flooding have been measured, it could be that they are a stage measurement, an elevation or water level, or a measurement to datum. Due to this uncertainty the thresholds have not assessed against stage at each gauge and, instead, an assessment of the timing of flood warnings issued in relation to gauge maximums has been made. In addition, this review has made use of 15-minute stage measurements taken from gauges located along the north and south banks of the River Humber and the Humber Estuary (Figure 15). The thresholds used by the EA to warn areas of flooding do not always come from a gauge for which information was available during this review. The approach has been taken to investigate stage levels at the nearest gauge for which information is available. Where this is the case, a note has been made to the fact and an approximate distance between the EA threshold gauge and the substitute has been given.
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Figure 15: Locations of Tidal Gauges on the East Yorkshire Coast and the Humber Estuary
Results During the storm surge of 5 December 2013, flood warnings were issued to multiple locations along the East Coast and along the Humber Estuary.
Further details regarding specific areas are included in the full report.
Flood Warning Areas Not Warned During the review, two areas were identified that did not receive flood alerts or warnings but which were shown to coincide with the flood outlines from the storm surge and high tides of 5 and 6 December 2013. These two community areas were in Hornsea and Saltend. Closer inspection has shown that digitised flood outlines overlap in very small areas of the two FWAs, suggesting that these areas were not actually flooded.
Conclusions During the storm surge and high tides of 5 and 6 December 2013, 14 community areas received flood warnings prior to maximum gauge levels being reached, whilst two communities, Hornsea and Salt End did not receive any. For those communities that received warnings, in all but two cases the warnings were received in advance, with lead in times ranging between 7.5 and 10 hours before the peak of the event. In the case of East Hull and West Hull, the lead in time was approximately 1 hour, which is low considering that other adjacent areas received warnings well in advance of these.
In many cases a second flood warning and in some cases a third flood warning or severe flood warning was also received with variable lead in times. Where an area received a second flood warning, the lead in time varied between less than 1 hour and 4 hours in advance of the peak. Of the nine areas where a second warning was issued there were three in which it was received less
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than two hours before the peak. There were two areas, Brough and Paull, that received a third flood warning. In each case this was approximately 1 hour from the peak. There were six communities that received a third warning in the form of a Severe Flood Warning. In all but one case this was received less than 1 hour ahead of the peak, whilst on one case it was received 15 minutes afterwards.
It is important to recognise that most areas received a Flood Warning prior to the peak of the event and that in most cases it would appear that sufficient warning time was available for residents and businesses, supported by the flood risk management authorities, to take action to reducing the consequences of flooding. It is, however, recommended that where no warnings were received and where warnings were received only 1 hour before the peak, that the trigger levels and operational procedures be reviewed to identify whether there is an improvement that could be made. What should also be reviewed is the suitability and effectiveness of second and third warnings, particularly where second warnings were received less than two hours before the peak and where the third warning was an hour or less before the peak.
Given the severity of the event, it could further be argued that the provision of Severe Flood Warnings was less effective relative to the provision of Flood Warnings in general. All areas that received a Severe Flood Warning only received these shortly before, or in one case, after the peak. It is recommended that operational procedures be reviewed to determine whether improvements to the timing of Severe Flood Warnings in relation to forecast peak levels can be made and whether there should have been more Severe Flood Warnings issued.
Assessment of the Flood Damage
Outline Economic Assessment As part of the investigation into the tidal surge of December 2013, an assessment has been made of the number of residential and non-residential properties shown to lie within the digitised extent of flooding along with an outline assessment of the economic impact of that flooding. This has been compared to similar analysis applied to those properties that lie within the 1 in 200 year, undefended tidal flood extent – derived from the Environment Agency’s Flood Zone Map – in order to identify the potential impact that such a significant event could have had on property within the East Riding of Yorkshire had there been no defences. The aim of the analysis is to put the properties and estimated damage into context by comparing it to what could have been. The analysis will indicate the level of benefit that the existing defences provide.
Methodology The following stages were followed in assessing the economic impacts of the tidal surge on properties within the boundary of the East Riding of Yorkshire.
• A combined digitised flood extent was created from the EA Flood Zone map – tidal models only – and the digitised December 2013 surge flood extent, which was based on aerial photographs of the flooding taken the day after the surge. • The properties at risk within the whole dataset were defined, after which the properties at risk within each area (Tidal Flood Zone Map, December 2013 Tidal Flood Extent) were identified. Properties locations have been derived from the National Receptor Database. • The Multi-Coloured Handbook (2013) weighted annual average damages (WAAD) method was used to derive a damage estimate for each property that was or could have been
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flooded assuming that an event has taken place – to do this the WAAD for each type of property affected in a 1 in 200 year event was multiplied by 200 to estimate the damage caused by the one event during that period that takes place. • Depth-damage curves for each type of property (Detached, Semi-detached, Flat or Bungalow) were also used to estimate damages for a range of potential flood depths. The process was repeated for each type of non-residential property within the study area using relevant depth-damage curves. Where the MCM code of the non-residential property could not be matched to the new MCM codes then the sector average was used. Where the MCM code indicated a miscellaneous land-use (noted by MCM code 9) the non- residential property (NRP) sector average was used. In all cases the short-duration, salt- damage, no-cellar damage values were used. • Property damages were capped by the average property value (by type) and by an estimate of typical rateable value per square meter of non-residential land-use over a 10 year period. • Vehicle damage costs were estimated using the method described in the latest version of the MCM, as were intangible costs, evacuation costs and the costs of Local Authority emergency services and recovery costs. • The dataset was filtered to remove land-use types/properties that are excluded from damages assessment. • The damage to properties that were not excluded was summed to provide an indication of the total damage by flood extent and within each flood extent by residential or non- residential property. Property counts were also undertaken.
It should be noted that there was only sufficient information to undertake an Overview level assessment of the potential damages experienced in the event and that the damages to other assets and infrastructure has been excluded. This includes:
• Electricity and gas transmission infrastructure; • Water and sewage treatment infrastructure; • Impacts on roads and rail infrastructure; • Telecommunications; • Schools and Hospitals; and • Agriculture and recreation.
Further discussion is presented later in this summary of the impacts of the different flood events on each, despite not quantifying the damages.
Results
Residential and Non-Residential Properties The results of the analysis indicate that the impact of the tidal surge was significant. At least 593 properties were shown to be located within the 2013 tidal surge flood extent although the number may be more because the extents were based on digitised aerial photographs of the flood extents taken more than 12 hours after the surge peak, on the morning following the flood event. There was an approximate 50:50 split between residential and non-residential properties in the area affected.
Using the WAAD approach, the direct-damage estimate, i.e. the damage sustained to the buildings and its contents, to residential and non-residential properties stands in the region of £8.8 Million,
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with a further £1.8 Million of indirect and intangible damages. The total damage is estimated to be in the region of £10.6 Million.
Applying a depth-damage curve approach indicates that the total damage for flooding that was on average 0.05m deep internally would amount to £7.6 Million, rising to £11.2 Million where the average internal depth was 0.1m. These estimates are on par with the WAAD approach, however, detailed information on depth at each property would provide a more accurate estimate. An internal depth of flood water equal to 0.2m would increase the damage estimate to approximately £17.2 Million.
A comparison of the above with the consequences of flooding that equals the extent of the tidal Flood Zone Maps indicates that the flooding may have been significantly worse without the presence of the tidal defences along the coastline.
The area of inundation indicated by the digitised 2013 surge extent within the East Riding of Yorkshire is approximately 2,600ha, located primarily along the coastline within the Humber Estuary and in places along the East Coast. In comparison, the undefended tidal flood extent covers an area of 49,430ha, which is 18.7 times greater than the area inundated.
The area inundated in December 2013 was approximately 5.3% of the total area with a tidal flood risk. The number of properties impacted by the tidal surge was, however, only 1.41% of the total number that lies within the area at risk from tidal inundated without the presence of defences, which lies at approximately 42,000. Of these approximately 72% are residential, which is much higher than the area affected by the tidal surge.
Using the WAAD approach, the direct-damage estimate, i.e. the damage sustained to the buildings and its contents, to residential and non-residential properties within the undefended tidal Flood Zone stands in the region of £615.4 Million, with a further £168.0 Million of indirect and intangible damages. The total damage is estimated to be in the region of £783.4 Million.
Applying a depth-damage curve approach indicates that the total damage for flooding that was on average 0.05m deep internally would amount to £604.8 Million, rising to £868.9 Million where the average internal depth was 0.1m. These estimates are again on par with the WAAD approach, however, detailed information on depth at each property would provide a more accurate estimate. An internal depth of flood water equal to 0.2m would increase the damage estimate to approximately £1.324 Billion.
It is notable that, whether the WAAD approach is taken or a relatively low-depth assessment of potential damages using a depth estimate, the damage estimate based on the digitised flood extent from the 2013 surge is not significantly higher than 1% of the potential damages that might have occurred in an undefended scenario. Comparison of the two damage estimates (surge against Flood Zone Map) indicates that the damages avoided by the presence of the defences was at least £600 Million, if not more.
It is likely that this figure would be reduced further by considering the extent and consequences of flooding from failure of the defences under these conditions. Despite this, it can be seen that the presence and continued maintenance of the tidal defences provides a significant benefit to the East Riding of Yorkshire.
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Other Land-Use Types Electricity and gas transmission infrastructure – There are four electricity sub-stations of up to 400KW located within the Tidal Flood Zone Map. Based on their size, three of these are likely to be Super Grid substations serving a large number of people, however, whilst susceptible to flooding there may also be a degree of transferability, which could reduce the impact of flooding upon them and the electricity grid in general. None of the four were affected by the December 2013 tidal surge.
The National Receptor Database also indicates almost 200 smaller electricity sub-stations within the Tidal Flood Zone Map, however, only two were shown to lie within the December 2013 tidal surge flood extent.
Water and sewage treatment infrastructure – Within the Tidal Flood Zone Map the following facilities are present:
• 1 water storage facility • 2 water treatment facilities • 2 water distribution facilities • 5 sewage pumping facilities • 2 sewage treatment facilities • 22 pump houses • 60 pumping facilities
Of the above assets, only 1 pumping facility is shown to have been affected by the recent tidal surge.
Impacts on roads and rail infrastructure – The following table compares the lengths of various types of road within the Tidal Flood Extent to those affected by flooding in December 2013. Table 11 indicates that there was an impact largely on minor and private roads as well as local streets within the inundated area. There was very little impact on B roads, A roads and no impact on Motorways, suggesting that the impacts on transport would have been predominantly local.
Road Type Length (km) in Tidal Flood Zone Map Length (km) effected by Tidal Surge Dec 2013 A Road 147.15 0.44 Alley 116.26 0.04 B Road 43.77 0.06 Local Street 790.50 9.15 Minor Road 401.05 10.89 Motorway 39.04 - Pedestrianised Street 1.20 - Private Road - Publicly Accessible 6.32 0.92 Private Road - Restricted Access 350.73 10.35 SUM 1,896.02 31.86
Table 11: Road Type
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Schools and Hospitals – Within the Tidal Flood Zone Map there are 55 schools and education facilities, however, none were located within the tidal surge extent. There are no hospitals shown to lie within either flood extent, however, there are numerous other health related facilities such as surgery’s, health centres and residential homes. Again, none were affected by the tidal surge.
Agricultural Land – The areas impacted by the surge are largely rural in nature and an analysis of the agricultural land classification of the areas inundated in comparison to the Tidal Flood Zone Map show that there was a notable impact on high quality agricultural land. The table below presents a comparison of areas under each classification.
Agricultural Land Class Area (ha) within Tidal Flood Zone Map Area (ha) effected by Tidal Surge Dec 2013 Class 1 5,115 232 Class 2 18,210 1,509 Class 3 - - Class 4 1,787 71 Class 5 380 - Non-agricultural 392 145 Urban 1,650 15 SUM 27,534 1,972
Table 12: Agricultural Land Class
Conclusions The assessment has identified that there was a significant number of properties affected by the tidal surge. Nearly 600 properties lie within the area shown to have been affected with an approximately 50:50 split between residential and non-residential uses. The direct damage to these properties caused by the flooding is estimated to be in the region of £8.8 Million, with additional indirect and intangible costs of approximately £1.8 Million (WAAD approach).
The appraisal highlights that the estimated damages associated with the tidal surge are a little over 1% of those that could occur in the absence of any flood defences, which highlights the value of the existing flood defences to the region and the benefit derived from continuing to invest in effective flood risk management measures.
The assessment highlights that there was relatively little impact from the tidal surge on important infrastructure, with only minor impacts on small electricity sub-stations, a pumping facility, and no impacts on schools or hospitals. However, there was a notable impact on roads in the inundated area with the consequences felt most acutely on local roads and streets and private roads. Grade 1 and 2 agricultural land was also heavily impacted.
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Limitations The damages associated with flooded properties that are presented within this report are based on information available within the Multi-Coloured Handbook and its supporting tables and figures, which are available for the purpose of estimating flood risk management benefits. The data presented in those documents has been developed from the recorded costs associated with a number of large flood events, including those in 2000 and 2007 which so heavily impacted the East Riding of Yorkshire. The damages are not a measure of the actual damage incurred during the tidal surge but instead allow an estimate of the damage from that event and from a hypothetical undefended 1 in 200 year tidal flood scenario for the purposes of comparison only.
The digitised flood extent data showing the extent of flooding from the tidal surge is based on aerial photographs taken the morning after the surge took place. The extent may have been larger at its peak more than 12 hours earlier with the result that the damage estimate for the event may be underestimated.
The assessment is an Overview level assessment, considering primarily the damages to residential and non-residential properties, as these are the land-use types for which damages are easily available. There would have been additional costs that have not been assessed within this study, such as those associated with impacts on the infrastructure identified above, impacts on agriculture and farming, disruption to travel, schools and local recreation and tourism, loss of business revenue. There would also have been direct damage to flood defence infrastructure.
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Appendix 6: Wind Speed and Direction Map
Showing the maximum wind speeds and the range of wind directions recorded on 5 December 2013 from each of the weather stations used in the data analysis.
The wind speed is indicated at the centre of each circle in km/hr, and the directions are shown on the radius arrows as a compass bearing in degrees. (270 degrees being a westerly wind, i.e. blowing from the West).
There is more than one direction indicated as the stations record the direction as a time related average!
(Wind speed of 41km/hr = 25.5miles/hr)
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Figure 16: Weather Stations
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Appendix 7: Anecdotal reports
A sample of the reports and comments submitted to Blacktoft Parish Council by residents affected by the Tidal Surge Flooding on 5 December 2013.
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Page 1 of 2 Sue
From: Sent: 02 March 2014 16:56 To: [email protected] Subject: TidalS urge 5/12/13
Dear Sirs,
You have contacted local residents and businesses for their experiences of the flood and Iam happy to set out our experience.
We farm about 700 acres in the parish and on that evening some 470 acres of this,half the buildings on one farmstead including a yard of cattle, were flooded in less than one hour. We attach photographs.
There has been damage to crops,roads,fertiliser in store,machinery,fencing and fodder. The cattle were left stood in water,despite having been moved into a higher building. These all had to be evacuated to a nearby farm after wards to allow their yard to be cleaned out. It is hard to fully calculate the cost of all this to our business at this stage. Some items are covered by insurance others, such as fencing,roads and ditches are not. Much of the cost will be the cost of the clean up. The buildings and yard were lined with mud, ditches filled with wreck and silt and we have spent days clearing up the debris from all over the land. Road repairs will be an expensive item.
On the day Ifelt that we were reasonably well organised. We were on the flood line and receive a warning and also viewed the web site. I also listened to Radio Humberside who were brilliant and giving good updates on the progress of the flood. Unfortunately no-one can listen to all the warnings and continue to make things as safe as possible at the same time. Two of us were off sick, one at college,which left only two people to prepare. There is a limited amount that anyone can do to mitigate an event of that magnitude. It would have taken days of work to move everything at risk to another site.The priority on the day was moving the cattle to a higher yard (where they were still subject to being stood in water).
Ithink we should mention that there becomes a risk to life when someone stays on site to see that the animals are all right. It is just one of those things that has to be done.
We were very lucky that there had been little rainfall for some time before,which meant that the drains got a good run off and the water cleared as quick as it did.
The economic impact has not been as bad as it could have been. Crucial in this were several facts.
1. that the water cleared so quickly, because of the original dry state of the land. This has meant the crops are damaged rather than lost. 2. The flood was at a very fortunate time of the year when the crops were established but in a dormant state. If this were to happen between April and November crop losses on our farm alone would have been around £300,000. 3. The farmsteads themselves were built on slightly higher ground and the corn store mostly have slightly raised concrete floors.This saved any damage to stored crops.
03/03/2014
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Page 2 of2
In short,in economic terms we have dodged a bullet. "!'
The economic importance of our business to the area is that we employ two full time people and one part time on the farm,together with two on the farm that is run together with this one, and also we lease a building to a fabrication company who employ four on the site. The jobs of the farm staff are entirely dependent on the continued viability ofthe farming operation. If this were to become a frequent event these jobs would no longer be viable.
I hope this gives a picture ofthe effect on our business as factually as possible without getting too emotive about the issue.
On the matter of human safety, Ithink the main risk to life was not to people in their homes, as is usually assumed,but to those travelling, who were liable to drive into the roadside ditches that were impossible to see. People feel the need try to get home to see if all is all right, or save animals or just help neighbours. There was also risk to those trying to keep the infrastructure operational.
Yours sincerely,
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Page 1 of 4<- Sue
From: - Sent: 21 February 2014 14:35 To: Sue Subject:RE: Blacktoft pc questionaire Good Afternoon Sue, t Here are our two accounts from being in the house and not being able to get to the house.
Name: Age:
Address:Newport
On the evening of the sth December 2013 Igot a phone call "it's flooding, ;it's flooding" It was a panic stricken voice with the deepest fear;on this occasion there was nothing but distress;this seemed unbelievable as the winds had been high during the day but the evening was calm. We went down in the car but ran into the floods 4ft and rising there were stationary vehicles including a land rover and a couple of different people standing around and we were informed the pumps into the canal were underwater;no one could get through at either end of Faxfleet. When I arrived I tried to ring the council emergency line for situations such as this. To my disgust the operator said "we don't know where Faxfleet is". I explained it was the next place after Blacktoft and that I could see blue flashing lights there.I was told "unfortunately everyone is in the same boat we have hundreds of people to help and alln we ca do is send a fireman but it won't be soon".Ifound this to be a sick pun I had told them I was worried about three pensioners and this was the response I had received. I had managed to get through to them on their mobile but only for a short while before this cut out as the battery died. Itried to walk through the water towards to house Ihad been trying to ring them back but the house phone was not working and now neither was the mobile. Once the water got to my hips I turned to go back not knowing now if the animals were died or alive or if the water would increase further and endanger their lives.
The next day 6th I went down to see ifthe water had moved at all to find it had not after a short while a fireman turned up after our call from the previous day. He said hcould not get through the water in the car and called for a boat. This he said would take some time as we would be in a long queue. I rang Lee Say who lives at the other end of Faxfleet lane to see if he could help me know what it was like there as I was still extremely worried about my parents and wanted to see them and know they were all right. He came to my rescue as he could get through in a tractor. Myself and the fireman went down to the house in the tractor.
When we arrive my dad andl 1were peeriog out of the bathroom window;they looked so petrified
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Page 2 of 4
there was fear in their eyes,voices and body language;they were shaking and traumatised. I told them we could et through in a tractor and I thought they should come to my house to get a warm drink and change of clothes. They had taken two small dogs upstatrs also as they would have drowned as they lived usually downstairs in cages. Iasked Lee to come back for us after we had collected some items and gone outside to see the animals unknowing if they were at this moment died or alive.
Inside the house the water was up to me knees we moved through the house to outside where the water flowed over the top of my boots. I took some pictures although this was after some water had gone down the next day (see attachments}.To our relief the horses were still alive and all right some water !lad gone into the stables but not enough to damage the animals themselves. We opened the dogs ors and thankfully because of the bales of straw they had all managed to climb up high enough not to have been drowned. The relief was tear breaking. •·
We packed up a few items and went outside the fireman went next door to check on the pensioner and we all climbed up into the trailer. Again the council acted in the most upsetting way towards us;they had come down using the tractor and then walked straight past us when we were loading the trailer (as seen in the photo}. After this they spent three weeks commuting between their house with the horses and dogs and my house to eat evening meals and see the smaller dogs who had now come in cages to live in my one room house.
Fortunately Iwas able to spend everyday with them helping to clear the dirt and help to restore the house to it's forma appearance outside which took hours of strenuous work. Works also started through the insurance inside.
Second Account
Name: • • •
Address:·
Live felt endanger: yes
On December 2013 sth we were sat watching television when. _ form JFaxfleet Lane knocked on the door and said the river is coming up the road;we couldn't believe it. We went outside and it was rolling up the road at walking speed. We came straight back into the house and had no time to do
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anything or save anything. By the time we had taken two little dogs upstairs the house downstairs was flooded.The
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Page 1 of 1 Sue
From: Sent: 18 February 2014 16:15 To: [email protected]
Subject: Anecdotal Evidence· )
Name·: Age:! Address:f Depth of flooding:House- none Garden - None Were we Frightened?: Bewildered rather than frightened
Story: I was sat in the house watching TV when I got the call from the environment agencies flood line, I
looked through the upstairs window and knew that the tide was looking exceptionally high but thought that if there was any leakage it would only be a little as after all it not ever flooded before since the bank levels were raised.
The next thing I knew was my grandson coming in and insisting on me moving out of my house and into his so we could be together and warm and dry hopefully. As we walked up the street to Ma·nor farm, Gary my grandsons house,he was insistent that Imoved quicker saying he could hear the roaring of the water coming over the bank and if we didn't get to safety the rushing river water would surely wash us both away. At the time 1 was rather ill so couldn't move very quickly and I remember thinking that he would end up grabbing me off my feet and carrying me the rest of the way, but that never happened. He deposited my in the house and went back out to see if there was anyone else he could go and help. By this time we could see the water com.ing from the west of the village so Gary went to help some older people down at that end.
Fortunately the water didn't get into either of our houses we were the lucky ones,I do think if we had been caught by it the results could have been fatal though. Luckily there are people in the village who were keeping an eye out for the old and more vulnerable residents of the village.
o ovostf This email is free from v..ir.u.ses and malware because avast! Antivirus protection is ..to.r'’ active.
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rage 1 u1 L.
Sue
From: Sent: 23 February 2014 09:43 To: Sue Subject:RE:Blacktoft pc que tionaire
Goodmorning Sue
The depth of water rose to the level of the small bank in the front of my garden.This was a frightening experieace because of the force of the wat4r which was bringing river debris and wheelie bins as it followed the road out ofthe village.
My story:
Ihave recently returned to living in the village which was my childhood home. Iwas in my home on the evening of the flood. I was having a conversation on the telephone when my neighbour was knocking on my door. She alerted me to the potentialflood. I had not heard the siren. She said she was leaving the village in the car with the children but her husband would be staying. Ihad no where to go so decided to concentrate on moving some furniture and personal items upstairs. I also telephoned some of my friends to let them know of my situation. Ifelt it was important to have food and drink upstairs because I did not know what damage could be caused to my home downstairs. Some people were leaving the village in their cars.It was like an evacuation!. Iremained upstairs and the flood water arrived. It was forcefuland dangerous removing and bringing debris in its flow. None of my neighbours left their homes so we were able to support each other whilst we watched the flood water rise. We were aware that some homes in the village would have been flooded by now. We were expecting the worse too. However,the level ofthe flood water began to decrease which was a reliefto us all as we watched its progress. The Environment Agency and firefighters arrived which was reassuring. Little sleep was achieved that night as Iwas anxious about what the next day would bring. When dawn broke I could see that all the fields surrounding our home were flooded with the river water. The road was flooded so access to the village was not possible in a car. In the following days Ispent my time helping out other villagers whose homes had been flooded. I could empathise having had my other home flooded during a recent severe winter.. It was evident that local people had a lot of knowledge about the area but was not immediately utilised by the services that were present,for example water was being pumped into the ditches which were already full and it continued to flood the road. Eventually,the water was pumped back into the river with success. The services were also asking my neighbours for spades to assist with this work. Therefore,they did not have enough basic equipment with them. However,Iknow that preparation and having the right working equipment available is essential in any emergency situation.
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PageL OIL
Flood water continued to be pumped out of flooded homes which took many days to complete. Their ruined cortents removed for disposal. Eventually,the village returned to some normality, as access to the village improved with removal of the flood water. However, flooded homes will need time to dry out before work can be undertaken and this will take many months. The affect of the flood will remain with me but no one lost their life in this emergency.
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Sue
From: Sent: 23 February LU14 n:1u To: [email protected] Subject: Anecdotalevidence-Tidal surge 5th December 2013
To whom it may concern, as requested please find our recollection of events on the 5th December 2013, provided below. Prior to the tidal surge we had been made aware of this being a potential risk due to media reports and alerts from the environment agency via telephone. However, when the severe flood warning was given via phone, at that exact same time our neighbours were knocking on our front door to warn us that the river was already coming over and they were evacuating the village. We rushed outside to see for ourselves and saw the river coming over a brick wall which is an extension between the river bank and the bridge which goes over the dyke adjoining the river. The water was also coming through the wall between the bricks, as well as through the stone section of the bridge over the dyke!! The water rose up the river bank in front of our house to within approx a couple of inches off the top of the bank! We watched helplessly as the water came over and through the wall, it moved down the road just beyond our row of 6 houses and then appeared to stop and then flow side wards into our gardens! We feel extremely lucky that although our front garden was flooded, as was much of the back garden, the water did not enter our house (though it rose to approx half an inch below both front and back doors). In hind site we wished that we had captured the flooding on film/camera, but this did not enter our minds at the time. In terms of whether or not we felt frightened, Tim did not he was just worried about our horne and the extent of damage that may be caused. I personally was 1 frightened and in a state of panic I was worried sick as there was no way of knowing how far the flooding would rise, what damage it would cause and whether or no it was safe to stay! I felt torn as I wanted to ensure that our pooch, neighbours, ourselves and our cars were out of harms way but felt that we had to stay to protect our home! The most alarming aspect during this incident was for us, the speed at which the water was taking over!!
Sent from my iPad
1
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BLACKTOFT P.ARISH COUNGIL ..
February 2014
Name......
Ad.dress......
Depth of flooding to property...... None
Found the experience extremely frightening and life threatening
My Story:-
On the evening of 5 December 2013 I was due to go to a friend's house for dinner at 7.30pm. We had a flood warning at 16.14 but at that time it was not severe. It had been a windy afternoon and I was late home because of traffic hold ups due to the weather. I got myself ready and went outside to see where Jimmy was. He was concerned about the river as it was rising very fast. My husband works for ABP so we went up on the Jetty and we watched the water lap over the concrete.
I have lived in Blacktoft 13 years and I had never seen that happen. It was only 18.40 and the tide wasn't due to peak until 20.00 yet it was already lapping over the jetty.The severe flood warning came at 18.52. The water continued coming up extremely quickly in so much as the jetty and the walkway were covered by 19.09.: ) had put the flood boards in earlier during the day and they held the water back (it was only a trickle that was getting through) Many residents had gathered at the entrance to the jetty where the flood boards .. were in place. It was considered,by most people,to be the weakest place as it was lower than the rest of the bank hence the reason the flood boards being deployed. We were all very worried that the water would come over as at this point it was within an inch or two of the top of the boards.
It was only some minutes later that someone shouted to say that the river had gone over the bank elsewhere at which point everyone dispersed. The water very quickly filled the street and bins were floating about within minutes. We were very lucky as our property was one of a few that stayed dry.
It was a most frightening experience having to travel through flooded roads to reach our home the next day and heart rendering to see the devastation suffered by most of our neighbours.
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BLACKTOFT PARlSH COUNCIL February 2014.
Name:.
Age (ifyou wish):
Address:
Depth of flooding to your property:
Were you frightened and did you feel your life was threatened?: ·\.1.<::- • • ......
Your story:
/ Although my property was not flooded on 5th December 2013, as a 70 years old, extremely vulnerable paraplegic woman living alone I am very concerned and afraid. If I had been flooded, I do not know what would have happened to me. It would be extremely difficult, for example, to find suitable accommodation and to recover all the medical supplies I need on a daily basis. The consequences of flooding would be seriously life-threatening for me.
The ensuing power cuts for example made it very difficult for me. As everything in my home is operated by remote control, I was unable to get in or out of my property, could not charge up my electric wheelchair, had no telephone contact and feel I was in a very dangerous situation having to bum candles and light fires to keep warm. In fact a candle did tipple over and bum my carpet. Fortunately it went out before causing too much damage. There is also the very real possibility of getting stuck in my through floor lift.
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From: .... Sent: 19 February LU'I4 LU:U To: [email protected] Subject: : Anecdotal evidence- tidal surge 5 December 2013
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> > My name is'' 'Yokefleet hall. and I live with .my partner• _)at
> On the 5th December 2013 I was travelling back from Birmingham and at > around 8pm as I entered Yokefleet village I rang who was at home, he said there was a power cut so I asked if he could meet me at the oottom of our stairs so he could help with my luggage as it was pitch black. During this time I,d travelled approximately the 400 yards throuqh the villaqe to within 20yards of the entrance to the hall.s drive. at this point a large wave hit my car and whilst I was still on the phone to1 I explained what was happening and that the water rose quickly over the bonnet or my car and within seconds the call ended as obviously the power to the cars hands free cut out because the car was underwater. "> > I tried to open the car door but could not as the force of water was > too great, luckily the window opened so I managed to get out and > swim/wade across to the property opposite the drive entrance as the > water was by now chest high. > > The family were all upstairs and guided me to the side door as they > couldn't open the front door, as aqain the force of the water >prevented it. I sustained many bruises as iron railing/fencinq and > other obstacles were under water which obviously I couldn't see. The > water was up to he window sills of the property. Once inside this > property, the residents gave me dry clothes to change into. "> > In the meantime, had phoned the police as he was worried what had > happened to me, ane knew was that I was yards from home and my car had been hit by the wave. The police advised him to look for me, which he did, as he left the the hall in his car it was pitch black he could see water down the drive but had no idea how deep it was, unfortunately it was deeper than he envisaged and he had to abandon it and make his way back to the hall in pitch darkness. > > After approximately 3 hours I was taken by the coastguard back to the > hall, although our flat was not damaged we had no electricity for 1 > week and most of our property in the hall garages was damaged. > > I understand from the coastguards that the helicopter was looking for > me, and I alerted the fire briqade and other services in attendance > who were around my car that I was ok and safe. > > The pictures that I've attached we're taken a couple of hours after >and you can see the the water had receded. My car is thel > which was written off, so was my partnersf There lS av a > video attached. > > You asked if I was frightened or felt my life was in danqer, I would > say most definitely yes, but I think adrenalin kicks in at the time > and you cope, however I did suffer flashbacks for qite a fe o-1 nights > a!terwards, and also when the weather has been bad recently with the > storms, I have felt nervous. > Page | 123
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Sue
From: Sent: To: Subject:
01 Marcn :.:u·1q 1 I.Lo ... [email protected] Anecdotal evdi ence -tidalsurge 5 December 2013
I was driving my car along Bellasize Lane from Green Oak Crossing towards Laxton. My car suddenly spun round out•of control and when it fina ly came t Sp halt my initial thought w s that I had hit black ice. I looked out of my side window and saw water half way up the window. I then thought I had skidded into the dyke which runs alongside the road. I The doors would not open easily due to the weight of the water and the windows would not open as the electrics on the car had died. I settled I struggled out of the car and realised I was surrounded by water and could tell by the bank which is at the opposite side of the road from the dyke that I was still on the road with my car facing in the opposite direction to my original route.
My only option was to wade through the water keeping the bank to my right as I had no sense at that point of how far the water spread or where I was in relation to the turn off to Laxton, and I just wanted to get out of the water as I had no idea what had happened or if there would be more water coming, and no way of contacting anyone as my mobile was lost when the water rushed in to the car.
I am 6' 4" tall and the water was just below my armpits. I waded through the water and eventually saw lights in front of me, which turned out to be the white drainage board landrover. When I finally reached the Laxton turn off my partner had arrived and was asking the drainage board men if they had seen me, they said they thought they had seen something move but hadn't thought there was anything wrong.
There were no warnings in place to indicate any chance of flooding on the road and I have no doubt that if I had lost consciousness I could have drowned, as no one had realised I was there.
Luckily I am tall and fit, in daylight and measuring the distance later, I had to wade through the deep water up to my armpits for half a mile. I was extremely cold and in shock. I have had nightmares about what would have happened if children, elderly or infirm people had been in the car as they would not have stood a chance.
It was a week before the road was drained sufficiently for my car to be recovered, which is a write off, along with my lap top and phone, which were in the car, however I feel extremely lucky to have walked away from what could have been very diffe nt outcome. ,, - 1 March 2014
Sent from my iPad
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Appendix 8: The Environment Agency’s Humber Flood Risk Management Strategy
Summary of the Strategy
Stated Aims and Objectives of the Strategy To manage the risk of flooding around the Humber Estuary in ways that are sustainable for the people who live there, the economy and the environment, taking into account:
• Natural estuary processes • Future changes in the environment (built or natural), sea levels or the climate
To ensure that all proposals are:
• Technically feasible • Economically viable • Environmentally appropriate and socially beneficial
This strategy produced in 2008 which is currently under review is the EA’s vision for managing the risk of flooding from the Humber Estuary over the next 25 years, with the forecast climate changes and sea level rise. Within it they take into consideration the impacts it will have on people, property and industry as well as on the areas landscape, history and wildlife.
The strategy is the EA’s long term plan for managing flood risk from the Humber Estuary, there are nearly 400,000 people living near the Humber Estuary who are at risk from flooding, along with major industrial sites and the country’s largest port complex. The Humber Flood Risk Management Strategy was published in 2008 after a 10 year development, consultation and approval process and was developed to help ensure that the vast majority of these people should continue to have a good standard of protection from tidal flooding.
However recent government budgetary changes mean that Partnership Funding applies, under which a proportion of the costs generally need to be found locally. This means that the strategy is no longer just the 'EA's', it can only work if it is jointly owned and so is currently being updated, and the ambition is that it will be jointly adopted by all of the Humber LLFAs.
The EA will continue to maintain all defences that are economically viable. When a defence needs to be improved, the EA will apply for funding from the National Flood and Coastal Defence Budget. However in the current financial climate some works will only proceed where partnership funding can be secured as the budget is limited. When this applies the EA will look for funding from other sources but if this is not forthcoming they may stop maintaining the defence.
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The EA believe that maintaining the existing embankment system on its present alignment everywhere would be uneconomic and would also result in a loss of inter-tidal habitat in the estuary. To comply with legal obligations (UK Habitats Regulations) this habitat would need to be replaced and this can be achieved by acquiring land and moving the defences back behind it, making more space for the estuary. This is known as Managed Realignment and, although it does come at a cost in terms of lost agricultural land, the EA believe it is essential if the other work in the Humber Strategy is to proceed and protect as many people and as much property and land as possible. A similar process must be followed by those wishing to develop areas of the estuary for commercial purposes (Siemens).
What does Managed Realignment involve? There are many examples of Managed Realignment sites around the UK and in Europe, including one created by the EA at Paull Holme Strays. The work itself usually involves building a new high quality flood defence behind the habitat area, then breaching the old defence and allowing inter-tidal habitat to develop naturally. The sites are typically colonised quite rapidly by vegetation, invertebrates, and wading birds.
In the few years since its creation the Paull Holme Strays site has become a valuable feature on the Humber shoreline, attracting many visitors. This demonstrates that if a managed realignment area is promoted for wildlife tourism then these sites can support businesses and create new job opportunities. Inter-tidal habitat also provides valuable feeding and nursery ground for fish such as flounder, herring and bass, and so can benefit commercial and recreational fishing.
Photograph 29: Paull Holme Strays site on 6 December 2013.
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This is only one option, however, and the future of any potential site will always be discussed with local people and partner organisations by the EA.
Another possible option in the upper estuary is flood storage sites, an area designed to flood during an extreme tidal event to reduce river levels elsewhere, these areas can also create inter-tidal habitat. The land could still be farmed, so rather than buying it, compensation for the occasional damage caused would be offered. For example there is an operational flood storage site, at Alkborough. This site filled on 5 December 2013 and so performed its storage role; it has not been possible to gauge its effectiveness on the day in terms of lessening flood impacts further upstream.
The defences in front of any proposed site being considered for realignment will directly protect agricultural land but few properties. Some of the defences along such areas on the estuary, for instance those at Skeffling, currently deliver a very poor standard of protection. However the business case for carrying out improvements is weak, as the amount of public money available for the work is low when a relatively small number of properties are directly protected. By moving the defences back to provide an area of new habitat and at the same time building new defences further inland, which would not otherwise have been affordable, a higher level of protection can be achieved and legal obligations met.
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Appendix 9: Flood resilience information for property owners
People who have been flooded before have found the following guides helpful:
The Environment Agency’s flood advice can be accessed here:
http://www.environment-agency.gov.uk/homeandleisure/floods/default.aspx
Two Environment Agency documents that might be particularly useful are: Protecting your home: http://cdn.environment-agency.gov.uk/geho1009brdl-e-e.pdf
and Temporary and Demountable Defences:
http://evidence.environment-agency.gov.uk/FCERM/en/FluvialDesignGuide/Chapter9.aspx?pagenum=10
Homeowners guide to flood resilience:
http://www.knowyourfloodrisk.co.uk/pdf/protection-guide.pdf
The National Flood Forum. Ready for flooding:
http://nationalfloodforum.org.uk/wp-content/uploads/Ready-for-flooding.pdf
The British Insurance Brokers Association (www.biba.org.uk). Guide on getting insurance for high risk flood areas:
http://www.biba.org.uk/UploadedFiles/600floodguide.pdf
The Royal Institute of Chartered Surveyors. A clear guide to flooding for property owners: http://www.rics.org/Global/Downloads/A_clear_guide_to_Flooding_for_ property_owners.pdf
The Association of British Insurers. A guide to resistant and resilient repair after a flood:
http://www.abi.org.uk/Publications/ABI_Publications_A_guide_to_resistant_and_resilient_repair_after _a_flood_670.aspx
More information is available on the ERYC Website, on the A to Z, F - 8 Flooding, Flooding and Flood Preparation.
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Appendix 10: Help for Businesses and Homeowners / Repair and Renew Grant
Application Criterion
Repair and Renew Grant Purpose of the Fund: The RRG will provide flood affected homes and business premises with up to £5,000 of grant funding to establish flood resilience measures to reduce the risk of future flooding and/or minimise the impact of future flooding.
Eligibility: The owners of the following premises are eligible for RRG;
• Residential properties (including accommodation such as static caravans occupied pursuant to a lawful planning permission as a sole or main residence) where habitable internal areas of the premise have been damaged by flooding between 1 December 2013 and 31 March 2014. • Business (including social enterprise) and charitable organisation properties where internal areas of the premise which are critical to the day to day operations (i.e. not storage sheds or warehouses) have been damaged by flooding between 1 December 2013 and 31 March 2014.
Criteria: The interior of applicant’s home or business premises must have been damaged by flooding (as defined in the Flood and Water Management Act) between December 2013 and March 2014 (as defined above).
• The applicant must not have received other sources of public or insurance funding to establish the same resilience measures applied for (such as Property Level Protection scheme). • Business applicants will need to comply with state aid requirement (a per annex C of the Flood
Support Schemes guidance at:
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/284174/Flood- Support-Schemes-guidance.pdf
A notification is being sought for all support provided through the flooding response, although likely to be deminimis for the RRG as not directly related to repair/recovery works)
Applicants should utilise advice on the Property Protection Adviser website:
(http://nationalfloodforum.org.uk/property-level-protection-community-tool/), and other sources of information referenced in this guidance, to help select the most appropriate resilience and/or resistance measures for the nature of the flood risk to their property.
Properties who will benefit from a wider community flood defence scheme which will be completed prior to the winter (October/ November) 2014 (negating any value that may be gained from any RRG aid) are not eligible to apply.
Timing: Applicants can apply from the 1 April 2014. The final claim date permitted for residential properties and businesses is 30 November 2014 where the application is made prior to works starting on site. For retrospective claims the deadline for applications is 31 January 2015 where the works are completed. This allows time for the Government to reimburse the council prior to 31 March 2015 for the grant payments the council makes.
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What Can You Apply For: Up to £5,000 grant funding towards 100% of the costs (including VAT) of purchasing and installing appropriate resilience measures from the eligible list identified in the guidance. Should an applicant choose to implement measures in excess of £5,000, the cost must be met from alternative resources.
Collaborative Applications: It is also anticipated that collaborative applications to establish community level resilience and/or resistance measures will be supported. For example, where a street of properties would like to work together to establish a more appropriate solution for all (based on a contribution of up to £5,000 per premise).
Guidance on Flood Resilience and Resistance Measures: An applicant is not required to seek professional advice prior to making an RRG application. However, an applicant could mistakenly select X:\Housing Transportation & Public Protection\2014\PB60 - Draft ER Flood Resistance & Resilience Grant Scheme - Residential Application Form 4apr14.doc resilience and/or resistance measures that will be of limited benefit to them. Applicants may obtain advice from a qualified competent person and retrospectively claim up to £500 towards the cost for this advice from the £5,000 grant. On request, the Council will carry out professional services for the applicant.
Retrospective Applications: Due to the nature of the flooding, many people are at very different stages of recovery. For example, many of those who experienced flooding due to the tidal surge in December 2013 have already (or are in the process of) implemented repairs, which may include the purchase and installation of some of the resilience and/ or resistance measures that will be eligible for the RRG support.
Retrospective applications will be considered where;
• An applicant has been flooded after 1 December 2013 and they have purchased and installed flood resilience and/or resistance measures which are eligible for support through the RRG. • Where an applicant needs to progress repair works prior to the launch of the RRG, or a decision on their application can be reached, they can purchase and install eligible resilience and/or resistance measures and apply for grant funding afterwards. Any incurred costs would be at the applicants own risk, subject to retrospective approval of their application. • An applicant has demonstrated value for money.
This note is a summary and interpretation of the Government’s current guidance. If in any doubt please contact the council’s lead officer for further advice.
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