Umweltbundesamt
Click to enlargeThe landscape water balance is out of equilibrium: Straightened rivers, sealed soils, and drained peatlands retain too little water in the landscape. The consequences: drought, declining groundwater levels, and flooding. The solutions: retain water through adapted land management, give rivers more space, allow floodplains to flood, and manage land and soil in a climate-resilient way.
A balanced landscape water balance is fundamental for healthy, resilient ecosystems, ensuring water availability for both humans and the environment, and enhancing nature's resilience to extreme weather events. However, climate change, intensive land use, and significant alterations to natural river and floodplain ecosystems are increasingly disrupting this balance.
In Germany, only 9 % of rivers and lakes are in good ecological condition, falling short of the European Water Framework Directive (WFD) goals. Simultaneously, pressure on soils and water bodies is mounting: drought periods are increasing, floods and heavy rainfall events are becoming more frequent, technical flood protection measures are reaching their limits, and irrigation demands are rising.
To effectively address these challenges, a fundamental shift is needed. From a currently drained landscape to a climate-adapted "sponge landscape" that retains, stores, and gradually releases water.
The term refers to the natural processes of water distribution and storage within a landscape. Water moves through and is stored in soils, plants, rivers, streams, lakes, and the atmosphere, thereby providing the landscape with resilience against disruptions. The landscape water balance encompasses all components of the water cycle:
A healthy, resilient water balance buffers climatic extremes, supports biodiversity, and serves as natural infrastructure for flood and drought protection. Broadly speaking, water quality also plays a role, as it affects human uses (especially drinking water supply) and the living conditions for ecosystems.
Over many decades, the water balance has been systematically altered:
As a result, large parts of Germany have become extensively drained landscapes where water is not retained but rather quickly diverted. The consequences include lower groundwater levels, drier soils, and an increased risk of flooding during heavy rainfall.
The climate crisis exacerbates existing problems: summer droughts intensify soil and river desiccation and lead to declining groundwater levels. Simultaneously, the frequency of heavy rainfall and flooding is increasing. During intense rainfall, water is rapidly channelled through rivers into the seas. This water is lost to the regional water balance. This is also due to the fact that a significant portion of former floodplain areas is no longer available - whether due to dikes, sealing, or land-use changes. Consequently, flood damages are worsening.
Intact floodplains store water and release it slowly during dry periods. Restoration improves water retention, promotes biodiversity, and contributes to climate protection through CO₂ sequestration in soils.
Example: The dike relocation at Sandau Süd on the Elbe River creates 124 hectares of floodplain area and helps reduce regional flood peaks.
A near-natural river course with side channels, meanders, flood channels, and gravel banks enables diverse habitats and improves water quality. River restoration measures are therefore not only ecologically valuable but also make sense from a water management perspective. Additionally, extensive and ecologically oriented water body maintenance can do much to improve and preserve the condition of water bodies in the long term.
Example: At the Alte Nebel in Mecklenburg-Western Pomerania, a 200-meter-wide development corridor was created with positive effects on the water balance and biodiversity.
In cities, rainwater is often directly channelled into the sewage system. Through green infrastructure like green roofs or rainwater storage systems, water can be retained and utilized locally: a significant contribution to climate adaptation. This not only protects against flooding but also improves the microclimate in cities.
Example: Rainwater management becomes educational at the Freie Waldorfschule in Prenzlauer Berg, Berlin. The schoolyard was unsealed and greened. Under guidance, staff, parents, and students design and maintain the resulting open spaces to store rainwater.
Another option is the use of treated wastewater for maintaining urban green spaces.
The need to adapt our landscape water balance extensively to climate change has been recognized and is a central component of the National Water Strategy and the Action Programme for Natural Climate Protection. Several funding instruments are available for implementing restoration and water retention measures:
The vision for the future landscape water balance is a sponge landscape: a diverse, structurally rich landscape that absorbs, stores, and slowly releases water. A functioning landscape water balance is not a luxury but a prerequisite for climate adaptation, sustainable agriculture, flood protection, and a habitable environment. It is the only way to counter the challenges posed by climate change, protect our water bodies, and preserve biological diversity.
Example: Retaining More Water in the Landscape: Conservation tillage (instead of ploughing) offers several advantages over conventional agriculture. By avoiding intensive soil disturbance like ploughing, soil structure is preserved, reducing erosion and improving water infiltration and storage. Additionally, organic material such as plant residue remains on the surface, enhancing soil fertility and biological activity. This leads to a more stable soil ecosystem in the long term and can reduce the need for fertilizers and pesticides.
Further information:
The UBA’s motto, For our environment (“Für Mensch und Umwelt”), sums up our mission pretty well, we feel. In this video we give an insight into our work.
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