Land for flood risk management—Instruments and strategies of land management for polders and dike relocations in Germany

Highlights

• Different measures require different types of instruments to reflect the various demands on land use and ownership.

• In Germany, budgetary constraints do not substantially hinder land management aimed at reducing flood risk.

• New statutory instruments under water law have not been fully embraced in the federal states.

• Water authorities prefer established forms of land management and have developed contractual solutions to compensate land users.

• It is important to explore strategies of land management in practice before introducing new instruments.

Abstract

Like many other countries, Germany aims to create flood retention areas via polders and dike relocations. As these measures require access to diverse plots, land acquisition is clearly a challenging task for the responsible water authorities. A revision to the national water law in 2017 introduced several new instruments for land acquisition, i.e. pre-emption rights and regulations to ease expropriation, in order to facilitate the realization of flood protection infrastructure. Nonetheless, interviews with representatives of Germany’s various water authorities have shown that, in practice, these new instruments are widely neglected in favor of established forms of land acquisition such as strategic land banking and familiar instruments of land consolidation. This contribution explores the reasons for this low uptake of the new instruments. The study also reveals that in terms of land management, there is considerable unclarity in regard to the management of land within controlled flood polders, in the dike foreland (floodplains) and between first and second dike lines, in particular which instruments are best suited to achieve practicable solutions.

Introduction

The gradual shift throughout Europe from flood protection to flood risk management has changed the way in which governments and local authorities deal with riverine floods (Disse et al., 2020; Dworak and Görlach, 2005; Hartmann and Albrecht, 2014; Klijn et al., 2008). Whereas the focus of traditional flood protection has been on dikes and other technical infrastructure to defend at-risk areas and deflect inundations into floodplains, flood risk management encompasses not only flood defense but also the reduction of vulnerabilities and mitigate the various factors contributing to flooding.

Flood mitigation by retaining water on land has been acknowledged and discussed in academic debates (de Bruijn, 2005; Hartmann et al., 2019; Schanze, 2017) and policy-making (Directive 2007/60/EC on the assessment and management of flood risks, 2007). Flood retention measures need land – whether to construct technical structures such as polders, to form retention areas or to be offered as compensation for impacts in nature and landscape caused by technical infrastructure. Clearly, in one way or another, flood risk management impacts the way in which land is used and thus demands careful land management. In Germany, land required for such measures is predominantly in private hands. This creates a problem for flood risk management, as private land ownership is stringently protected by constitutional law (see Art. 14 German Constitution – Grundgesetz, 1949). This is why this contribution focuses on land management for flood retention.

The technical and hydrological factors of flood risk management are relatively well known (Bornschein and Pohl, 2017; Patt and Jüpner, 2013). Usually, flood risk management deals first with these specific technical and hydrological issues, i.e. planning the requisite infrastructure, before securing the required land. However, the implementation is hampered by insufficient strategic clarity regarding the most beneficial forms of land management (Hartmann et al., 2019). To acquire land, public authorities responsible for flood risk management have several instruments of land management at their disposal, i.e. legally-regulated public procedures to transfer the required land. These instruments range from land acquisition, i.e. cases in which the full property rights (ownership) are transferred to the water authority, to changes in the use or disposal rights, such as easements or other contractual agreements. The instruments and the conditions of their practical application are defined by law. Despite some exceptional instances of informal and voluntary arrangements (Raska et al., 2019), such legal instruments are essential for the realization of flood risk management.

Spurred by several major riverine floods over the past few decades, the German legislator determined to reform water law, specifically the Federal German Water Act (Wasserhaushaltsgesetz, WHG, 2009), in order to improve flood risk management. These legal amendments have improved and strengthened existing instruments as well as establishing entirely new instruments (Hartmann and Albrecht, 2014). The “Flood Control Act II” of 30 June 2017 was designed to “further improve flood protection” (Bundesregierung, 2017; Hofmann, 2017; Reinhardt, 2017). In view of the many advances in water law over the past two decades, it can be assumed that Germany now has a comprehensive toolbox of instruments on hand to ensure the acquisition of sufficient land for flood retention. This makes the country an interesting laboratory to explore the suitability of different instruments.

Our contribution aims to explore the strategies of land management pursued by the water authorities for flood retention measures, specifically polders and dike relocations. The interdisciplinary approach we have adopted (see Section 2) encompasses the following research questions and steps: First, we explore why and to what extent land is needed for polders and dike-relocations by reviewing the relevant literature and policy documents as well as by considering interviews with practitioners (Section 3); second, we provide an inventory of legal instruments to manage land for polders and dike relocations as defined in German water law (Section 4); third, we explore and discuss the practical application of the instruments (Section 5) and the reasons for the activation or neglect of individual instruments on the basis of interviews with practitioners (Section 6). Finally, we draw some conclusions on the introduction of new legal instruments of land management in flood risk management (Section 7).