The Sigma Plan is an integrated flood protection plan that was firstly established in 1977, in reaction to a major storm surge flood in 1976. The Sigma Plan offers protection against storm surges as well as river floods caused by excessive rainfall. Its objectives also include nature protection.
This case study describes the flood risk management plan and the related restoration of a formerly canalized eight kilometres stretch of the Isar river in the city of Munich (the so called “Isar Plan”). Still in the beginning of the 19th century, the Isar was a typical wild alpine river with wide gravel islands and sandbanks and a constantly changing riverbed. In the middle of the 19th century after repeated flooding suffered by the Lehel, Au and Thal districts in Munich, hydraulic regulation began, and the riverbed was canalized.
The Flemish coast is intensively used by many actors, embracing coastal towns, commercial ports connected to industrial areas, leisure marinas and touristic activities. It is exposed to flooding due to storm events and sea level rise. In 2007, the Flemish Government, after a safety test revealing an insufficient protection of the coast, started the elaboration of an Integrated Master Plan for Coastal Safety that was finally approved in June 2011.
Hesketh Out Marsh is one of the biggest managed realignment projects in the UK and is one of the country’s most important estuary habitats for birdlife. The original saltmarsh was isolated from the estuary in 1980 by the creation of an outer wall, and was used for growing crops. With the sea level rising, it was necessary to create stronger sea defences. By a process known as “managed realignment”, seawater has been let back in to flood the land, re-creating saltmarsh and providing space for nature.
As a result of sloped topography and impermeable ground surface, the Gomeznarro Park in Madrid was affected by erosion during heavy rainfall events, and the surrounding residential areas suffered from flash flooding. In response to these problems, in 2003 complex works aiming at improving the natural drainage and rainwater retention were carried out in the park.
The Kis-Sárrét area is located in south-eastern Hungary close to the Romanian border. The area is part of the Körös-Maros National Park and is included in the Natura 2000 network. It hosts numerous plants, animals, and habitat types of EU community importance. Its landscape has undergone dramatic changes during the past 200 years. In particular, extensive marshes were reduced and altered as a result of water regulations between 1856 and 1879. As a consequence, many areas constantly or temporarily covered by water disappeared, and the traditional management of the natural landscape changed.
The area of the Eferdinger Becken, Upper Austria, is a small area that lies on the Danube. It has no protection against floods with a 100-year return time: the flood-prone area includes about 154 houses that flood regularly. Due to the importance of the retention space for the discharge and the difficult technical feasibility, passive flood protection was considered as more suitable. Homeowners needed to decide on relocation by the end of 2015. The federal and the regional governments compensate citizens 80% of the value of the house if they agree to move.
Normally a shallow river, the White Cart Water was prone to flash flooding. Its water levels can rise by six metres after just 12 hours of rain, which threatened vulnerable Glasgow suburbs downstream. Public awareness of such flooding risks in the 1980s and 1990s, and projections of more intense periods of rainfall made devising a flood prevention scheme a priority for the Glasgow City Council.
Kristalbad is an area of about 40 hectares located in the east of the Netherlands between the cities of Enschede (160.000 inhabitants) and Hengelo (81.000 inhabitants). This is one of the last remaining green areas between these two cities, playing a role for ecosystem-based adaptation to cope with potential climate change related impacts.
Isola Vicentina (Italy) signed the EU’s Mayors Adapt initiative (current Covenant of Mayors for Climate and Energy) in 2014 and since then started the elaboration process of its Municipal Water Management Plan (MWMP) in order to integrate climate change adaptation into its water management policies. For this purpose, Isola Vicentina Mayor engaged the “Planning Climate Change” research group at the IUAV University of Venice and Green-Dev studio, a local consultancy firm.