NOT PROTECTIVELY MARKED Multi-Agency Flood Response Plan ANNEX 4 TECHNICAL INFORMATION Prepared By: Isle of Wight Local Authority Emergency Management Version: 1.1 Island Resilience Forum 245 Version 1.0 Multi-Agency Flood Response Plan Date: March 2011 May 2010 BLANK ____________________________________________________________________________________________ Island Resilience Forum 246 Version 1.1 Multi-Agency Flood Response Plan March 2011 Not Protectively Marked Annex 4 – Technical Information Contents ____________________________________________________________________________________________ Annex 4 – Technical Information Page Number 245 Section 1 – Weather Forecasting and Warning • Met Office 249 • Public Weather Service (PWS) 249 • National Severe Weather Warning Service (NSWWS) 250 • Recipients of Met Office Weather Warnings 255 • Met Office Storm Tide Surge Forecasting Service 255 • Environment Monitoring & Response Centre (EMARC) 256 • Hazard Manager 256 Section 2 – Flood Forecasting • Flood Forecasting Centre 257 • Flood Forecasting Centre Warnings 257 • Recipients of Flood Forecasting Centre Warnings 263 Section 3 – Flood Warning • Environment Agency 265 • Environment Agency Warnings 266 • Recipients of Environment Agency Flood Warnings 269 Section 4 – Standard Terms and Definitions • Sources/Types of Flooding 271 • Affects of Flooding 272 • Tide 273 • Wind 276 • Waves 277 • Sea Defences 279 • Forecasting 280 Section 5 – Flood Risk Information Maps • Properties at Flood Risk 281 • Areas Susceptible to Surface Water Flooding 282 • Watercourses Designated as Main Rivers 283 • Historical Flooding 284 • Coastal Flooding – Flood Zone 2 285 • Coastal Flooding – Flood Zone 3 286 • Coastal and Fluvial Flooding – Flood Zone 2 & 3 287 • Flood Defence Locations 288 • Coastal Cells and Predicted Extreme Sea Levels 289 ____________________________________________________________________________________________ Island Resilience Forum 247 Version 1.1 Multi-Agency Flood Response Plan March 2011 Not Protectively Marked Annex 4 – Technical Information Contents ____________________________________________________________________________________ Annex 4 – Technical Information Continued Page Number Section 6 – Flood Warning Areas 291 • Communities provided with a Flood Warning Service 292 • Community Flood Risk Summaries 293 • Causes of Flooding in Main Catchments 295 • Key Flood Risk Locations 296 • Flood Warning Area Map 297 • Bembridge 301 • Carisbrooke and Hunny Hill on the Lukely Brook 305 • Cowes, East Cowes and Newport 309 • Freshwater on the Western Yar 317 • Gurnard 321 • Gurnard on Gurnard Luck 325 • Langbridge and Alverstone on the Eastern Yar 329 • Newport on the River Medina 333 • Ryde 341 • Ryde on the Monktonmead Brook 347 • Sandown 353 • Sandown, Brading and Bembridge on the Eastern Yar 359 • Wootton and Seaview 365 • Yarmouth 371 Section 7 – Flood Response Resources • Sandbag Policy 375 • Flood Defence Equipment 375 • Flood Rescue 376 • Water Rescue 376 • Flood Water Pumping Services 377 ____________________________________________________________________________________________ Island Resilience Forum 248 Version 1.1 Multi-Agency Flood Response Plan March 2011 Not Protectively Marked Annex 4 – Technical Information Section 1 – Weather Forecasting & Warning ____________________________________________________________________________________________ Section 1 - Weather Forecasting and Warning 1.1 Met Office The Met Office is a Trading Fund within the Ministry of Defence and the official source of meteorological information in the UK, providing a number of services for use by the emergency services, government, military, general public, businesses and other organisations. 1.2 Public Weather Service (PWS) This service provides a range of basic weather information and related warnings that enable the UK general public and emergency responder organisations to: • make informed decisions in their day to day activities • to contribute to the protection of life, welfare and property in the event of severe weather • to warn of the potential for widespread disruption of communications or transport 1.2.1 Public Weather Service Advisors The Met Office has a wide range of professional and technological resources to aid responder organisations in the management of an emergency. These resources can be requested for both severe weather situations and where weather will have an impact, so that responders can be sure of consistent and effective meteorological input to the management of the emergency. The Met Office’s team of regionally based Public Weather Service (PWS) Advisors are available to work with emergency responder organisations to assist in planning and responding to emergencies. The role of the Advisor, in an emergency, is detailed in Annex 1 – Roles, Responsibilities and Actions. ____________________________________________________________________________________________ Island Resilience Forum 249 Version 1.1 Multi-Agency Flood Response Plan March 2011 Not Protectively Marked Annex 4 – Technical Information Section 1 – Weather Forecasting & Warning ____________________________________________________________________________________________ 1.3 National Severe Weather Warning Service (NSWWS) As part of the Public Weather Service, this service provides advance notice warning of severe weather conditions likely to cause: • widespread disruption • widespread damage • risk to life so that the general public and emergency responder organisations can take action to reduce its impacts during and after the event. 1.3.1 Advisory Warnings • Issued by 13:00hrs daily, on the Met Office website • Indicating 20 - 60% confidence of severe or extreme weather • With the potential to lead to a high-impact weather situation • Aims to distinguish between severe and extreme situations by a traffic light colour matrix that indicates a percentage of confidence that severe or extreme weather is expected The traffic light system colours should be interpreted as: ‘Be aware’ means: Remain alert and ensure you access the latest weather forecast. ‘Be prepared’ means: Remain vigilant and ensure you access the latest weather forecast. Take precautions where possible. ‘Take action’ means: Remain extra vigilant and ensure you access the latest weather forecast. Follow orders and any advice given by authorities under all circumstances and be prepared for extraordinary measures. ____________________________________________________________________________________________ Island Resilience Forum 250 Version 1.1 Multi-Agency Flood Response Plan March 2011 Not Protectively Marked Annex 4 – Technical Information Section 1 – Weather Forecasting & Warning ____________________________________________________________________________________________ Advisory Warning: Severe Weather - Example Expected on a semi-regular basis, particularly in winter Colour and risk levels for severe weather events Green Yellow Amber Warning None Advisory Early Flash Very low Low Moderate High Very high Risk <20% ≥20% <40% ≥40% <60% ≥60% <80% ≥80% Severe weather is Moderate risk of High risk of severe Headline No severe weather expected imminent or is severe weather weather occurring High risk that there Very high risk that Moderate risk of will be some there will be some some damage to Impact damage to damage to infrastructure and infrastructure and infrastructure and local disruption local disruption local disruption Ensure you Remain vigilant access the latest Ensure you and ensure you weather forecast Advice access the latest access the latest and take weather forecast weather forecast precautions where possible ____________________________________________________________________________________________ Island Resilience Forum 251 Version 1.1 Multi-Agency Flood Response Plan March 2011 Not Protectively Marked Annex 4 – Technical Information Section 1 – Weather Forecasting & Warning ____________________________________________________________________________________________ Advisory Warning: Extreme Weather - Example Much rarer and may occur typically only once or twice a year Colour and risk levels for extreme weather events Green Yellow Amber Red Warning None Advisory Advisory Early Flash Very low Low Moderate High Very high Risk <20% ≥20% <40% ≥40% <60% ≥60% <80% ≥80% Extreme weather No extreme Low risk of Moderate risk of High risk of Headline is imminent or weather expected extreme weather extreme weather extreme weather occurring High risk of major Major damage to Low risk of major Moderate risk of damage to infrastructure and damage to major damage to infrastructure and Impact the environment is infrastructure and infrastructure and the environment. likely. Casualties the environment the environment Casualties are are possible possible Remain extra Remain extra vigilant and vigilant and access the latest access the latest weather forecast. Remain vigilant weather forecast. Follow orders and Ensure you and ensure you Be aware of risks any advice given Advice access the latest access the latest that might be by authorities weather forecast weather forecast unavoidable. under all Follow any advice circumstances and given by be prepared for authorities extraordinary measures ____________________________________________________________________________________________ Island Resilience Forum 252 Version 1.1 Multi-Agency Flood Response Plan March 2011 Not Protectively Marked Annex 4 – Technical Information Section 1 – Weather Forecasting & Warning ____________________________________________________________________________________________