Historically, coastal flood protection levels have differed widely on each coast. There are 540 km of coast at the Baltic Sea in Schleswig-Holstein, only short sections of which are protected at all. State dikes, the highest level of protection, at an average height of 4.0‑4.6 metres above MSL, protect 67 km of coast. An additional 54 km of Baltic Sea coast are protected by regional dikes, which do not have a uniform design standard and generally do not protect to the same level as state dikes (MELUR, 2012[3]). At the North Sea, the situation is quite different, as state dikes protect 364 km of the 553 km long coast, and the state embankments have a general height of about 8-9 m above MSL. These differences reflect varying hydro-morphological settings between the coasts. On the North Sea coast, a mean tidal range of up to 4.0 m has to be considered in the necessary height of embankments, whereas the Baltic Sea coast is a micro-tidal environment. Further, due to the shallow water environment of the Wadden Sea, the surge levels along the North Sea coast are much higher than those along the Baltic Sea coast.
The coastal defence master plan, developed by state governments, is the key coastal risk planning instrument in Germany. It sets out the state dikes’ safety standards and areas of general welfare interest. The first Schleswig-Holstein Master Plan was developed in 1963 following the 1962 storm surge, in which the failure of protection led to widespread flooding and several hundred fatalities. The Master Plan is regularly updated (1977, 1986, 2001 and 2012). Flood safety standards have moved towards a more harmonised approach between the North Sea and the Baltic Sea.
The current Master Plan planning process is based on an integrated coastal zone management (ICZM) concept, which was adopted in German federal law in 2006 through the national ICZM strategy (BMU, 2010[5]). The scope of the ICZM strategy is intersectoral planning for the marine environment, as well as coastal land use, and thus entails coastal protection decisions. ICZM stipulates that all relevant stakeholders for a given planning process are able to communicate their interests in the planning process. This includes federal ministries as well as federal states and their ministries, and private sector actors including civil society. The Master Planning process is thus a participatory process and gives the opportunity for public and private stakeholders to comment, and further requires an environmental impact assessment that considers national and EU regulations for nature conservation. A key instrument in this process is the “Advisory Council Integrated Coastal Protection Management”, which exists in Schleswig-Holstein since 1999. Under the chairmanship of the minister responsible for coastal protection, coastal protection stakeholders meet twice a year to discuss general aspects of coastal protection, and major individual measures, in an open exchange and in advance of decisions (see Chapter 3). In addition to the coastal and nature conservation administrations, members include the municipal districts, towns and municipalities, water and soil associations, and nature conservation associations. For example, the updates to the General Plan for Coastal Protection, which take place approximately every ten years, are presented and discussed in depth during its creation, in addition to regional citizens’ information events. Approval of the plan rests with the Schleswig-Holstein state government. The ministry responsible for CPCFD (Ministerium für Energiewende, Landwirtschaft, Umwelt und ländliche Räume des Landes Schleswig-Holstein, MELUR) establishes the plan, thereby considering all relevant regulations, comments and the environmental impact assessment (BMU, 2010[5]).
The 2012 update of the Schleswig-Holstein Master Plan introduced a uniform flood safety standard of the 1-in-200-year event for the entire Schleswig-Holstein coast, partly to meet the EU Flood Directive. The design water height is thus determined using statistical modeling, incorporating an allowance for SLR, provided the resulting protection level against the 1-in-200-year event is not lower than the observed highest water levels. Further, design water heights SLR allowance used a unified 0.5 m MSLR scenario to 2100 for both the North Sea and the Baltic Sea. The sea-level rise scenarios were updated to reflect increases in the projected level and range of future SLR following the IPCC’s Third Assessment Report. SLR of 0.5-1.4 m in this century was thus considered n the 2012 Master Plan.
In order to deal with increased future SLR, and also increased uncertainty, Schleswig‑Holstein implemented a flattening of the outer embankment slope and a widening of dike crowns from 2.5-5.0 m during their reinforcement. With this profile, the embankment may be further heightened in a second phase at relatively low cost and little planning efforts. Thus, in two phases, an SLR of about 1.5 m can be accommodated. Dike widening will, as far as possible, occur on the land side of the dike in order not to disturb valuable ecosystems, e.g. salt marshes, on the seaward side.
For areas not under the responsibility of the state, the Master Plan mentions alternative means through which local communities can access federal state funding. For funding purposes, a so-called “Förderrichtlinie” (legal conditions for obtaining state funding for CPCFD measures) exists. For instance, the Master Plan mentions that sea-level rise will lead to increasing costs to maintain regional dikes that could overwhelm local authorities. In such cases, the responsibility (and ownership) for these regional dikes can be taken over by the federal state, provided that the dikes in question protect lives and assets comparable to those protected by state dikes. The decision to take over regional dikes is taken on a case-by-case basis and the process must be initiated by the responsible local authority. This is discussed further below (Section 4.2.1).
Finally, a further aspect of the Master Plan concerns measures to protect against coastal erosion. Responsibilities for measures against coastal erosion are stipulated in the State Water Act, i.e. coastal protection measures on islands that are in the public interest (welfare) are a state obligation. For instance, on the island of Sylt, approximately 12 million cubic metres of sand were pumped for beach nourishment at a cost of approximately EUR 61 million between 2001 and 2011. Indeed, annual spending by the federal state at Sylt has been approximately EUR 6 million for combatting coastal erosion since 1983 (MELUR, 2012[3]). Public interest is underpinned by the fact that 22 000 people live on the island and would lose their place of residence if coastal protection were to cease. The State Water Act and its stipulations are the result of a political debate and represents, as such, a societal consensus (decided upon by democratically elected state parliamentarians).