Event™ July 12Th 2013
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FLOOD DAMAGE SURVEY REPORT eVENT™ July 12th 2013 2013 Elbe and Danube Floods in Germany, Austria and Central and Eastern Europe Willis’ post-event field damage survey report As the flood wave travelled down from the headwaters of Rivers Elbe and Danube, members of the Willis Flood Team spent five days in the field surveying water depths and damages caused by the floods across the affected region. In addition, the teams assessed the effectiveness of flood defences along the banks of rivers in Germany, Austria, and Czech Republic. This report summarizes the findings from this damage survey, including the use of mobile technology, and details the development of the Willis Flood Footprint. Overview In June 2013, much of southern and eastern Germany, northern Austria and western Czech Republic were affected by significant flooding caused by prolonged heavy rainfall over the region. In many areas, these were the largest floods since the devastating Elbe and Danube floods of 2002 and in some locations along the Danube, Saale and lower Elbe, the floods were the worst in recorded history. As the flood wave travelled down Rivers Elbe and Danube, representatives of Willis and the Willis Research Network (WRN) spent five days in the field surveying the affected regions. The main objectives of the damage survey were to: a) survey flood depths and extents, b) assess the damage caused by the floods to individual properties, and c) assess the effectiveness of the flood defences throughout the region. Despite road closures and the remaining flood waters, the survey teams were able to visit a number of affected locations in Bavaria in Germany, Lower Austria, and Prague and surroundings in Czech Republic. In order to accurately track the location of the surveyed locations, the Willis survey teams used consumer mobile technology combined with ArcGIS Online. The ArcGIS Collector app for iPhone allowed the survey teams to use the GPS and mobile data connections to upload the location, extent of damage and photographs to an online repository. In this way, Willis employees and clients in offices around the world could monitor the evolving flood and survey progress. The survey team in Austria observed many examples of well-drilled emergency services, highly efficient and effective flood defence structures and substantial natural floodplains and retention areas. In Prague, further examples of demountable flood defences were observed in addition to flooding behind these defences caused by high water levels and sewer surcharging. In contrast, the survey team in Germany visited locations where defence structures had failed and was able to survey a number of affected properties as flood waters had receded. Figure 1 shows the locations throughout the region visited by the Willis survey teams. © Copyright 2013 Willis Limited / Willis Re Inc. All rights reserved: No part of this publication may be reproduced, disseminated, distributed, stored in a retrieval system, transmitted or otherwise transferred in any form or by any means, whether electronic, mechanical, photocopying, recording, or otherwise, without the permission of Willis Limited / Willis Re Inc. Some information contained in this document may be compiled from third party sources and we do not guarantee and are not responsible for the accuracy of such. This document is for general guidance only and is not intended to be relied upon. Any action based on or in connection with anything contained herein should be taken only after obtaining specific advice from independent professional advisors of your choice. The views expressed in this document are not necessarily those of Willis Limited / Willis Re Inc., its parent companies, sister companies, subsidiaries or affiliates (hereinafter “Willis”). Willis is not responsible for the accuracy or completeness of the contents herein and expressly disclaims any responsibility or liability for the reader's application of any of the contents herein to any analysis or other matter, or for any results or conclusions based upon, arising from or in connection with the contents herein, nor do the contents herein guarantee, and should not be construed to guarantee, any particular result or outcome. Willis accepts no responsibility for the content or quality of any third party websites to which we refer. Figure 1: Extract of field survey locations visited by the Willis Flood Teams throughout Germany, Austria, and Czech Republic with an example survey point Germany Damage Survey The Willis survey team visited Fischerdorf, Niederalteich, and Winzer near Deggendorf, some of the heaviest affected communities in southern Germany on 11th June (see Figure 1 for locations). Fischerdorf were affected by levee failure along the Isar, while Niederalteich and Winzer were affected by a levee failure on the Danube downstream of the confluence with the Isar. In Bavaria, many 100’s of hectares were still inundated a number of days after the main floodwaters had peaked closing off the main highway to Passau (E56) and many smaller country roads in the wider area. Although the flood waters had receded and flood depths reduced, many streets and properties were still inundated. The standing water in most locations was less polluted than expected but in places, contained significant traces of oil and sulfate components. Figure 2: Flooding in Fischerdorf with a) receding flood waters from the Danube and b) a flood property with water marks on the buildings and surrounding trees. The survey team managed to gain access to properties in Fischerdorf while the clean-up was ongoing. The properties had been severely affected as a result of a defence breach. Water depths of up to 2 m from ground level were observed (Figure 3a) and surrounding properties on lower ground experienced water depths of 3 m above ground level (Figure 3b). Most residential properties surveyed were of masonry and reinforced masonry construction such that structural damage was limited despite the significant water depths. On the other hand, the majority of contents from basements and ground floors were a total loss (Figure 3c). In particular, electrical equipment such as washing machines and dishwashers were amongst the damaged goods. Upon inspection, many properties were pumping excess water out of basements, some of which was polluted with oil. Page 2 of 9 Figure 3: Survey findings from Deggendorf and surrounding area with a) water depths in ground-level of buildings up to 1.5m, b) water depths up to 3 m in other properties and c) total loss of contents from basements and ground floors Commercial damages in the area included a number of car dealerships and car rental companies in Fischerdorf, most of whom lost the majority of their stock. For instance, the local BMW dealer lost ~400 cars during the event. Flood Defence Integrity The wider Deggendorf area is protected by permanent flood defences but experienced at least two breaches along both Isar and Danube. In Winzer and Niederalteich many flood defences required additional reinforcement using sandbags or spare earth in order to protext communities during the event. In addition, high groundwater levels put significant pressure on already strained flood defences causing further weakening of defence structures and causing widespread flooding in basements. In places, defences were dismantled in order to relieve pressure points (Figure 4a). Demountable gate flood defences were also evident throughout the region protecting smaller parts of communities (Figure 4b) although flooding behind these defences was observed where defences had failed elsewhere (Figure 4b). Figure 4: Flood defences in Deggendorf and the surrounding area where a) flood defences close to Winzer were dismantled to relieve pressure and b) demountable flood defence gates built into a permanent dyke. Austria Damage Survey In most of the areas affected by flooding in Lower Austria, the emergency services restricted access to roads and buildings still under water and those at risk from further flooding. Figure 5 demonstrates the clear signage in operation throughout Austria for both major and minor roads where road closures were strictly enforced. The Willis survey team made their way from Mauthausen in Upper Austria to Klosterneuberg and Hainburg in Lower Austria along the banks of the River Danube , following the flood wave. Downstream of Mauthausen, many small country roads in Machland connecting Au an der Donau, Baumgarten and Mitterkirchen im Machland were closed to traffic due to high water levels from the Danube causing localised backwater flooding on the Rivers Naarn and Aist. Page 3 of 9 Figure 5: Clear signage and strict road closures were in operation throughout Austria In Grein, the 1 km long demountable flood defence protected the majority of the town with around a dozen houses affected by the high water levels on the River Danube. Outside the demountable defences, the affected houses were already starting the clean-up operation a day or two after the peak floodwave had passed. Figure 6a illustrates the impact of the flooding on contents and Figure 6b shows the clean-up process with emergency services and local residents working together. Figure 6: Flooding and clean-up operation in Grein where a) shows the impact on a flooded house and b) shows the emergency services clearing away flood waters and silt In the Wachau valley of the Danube River, the towns of Melk and Emmersdorf were badly affected by the flooding. In Emmersdorf, the local community and emergency services were clearing away the damaged contents and attempting to move the debris and waste left by the flood waters (Figure 7a). Water depths of up to 2-3 m were observed in both commercial and residential properties (Figure 7b) with significant damage to contents. Observed structural damage was limited due to mostly concrete or reinforced masonry construction types. Figure 7: Flooding in Emmersdorf with a) emergency services attempting to clear away the debris and b) water marks on commercial buildings Page 4 of 9 In Klosterneuberg, a few hundred properties were inundated up to 1 km from the main channel of the River Danube and in Kritzendorf, a number of properties by the river banks were under 2-3 m of water (Figure 8a).