EU Policies Aligned to Restore Landscape Sponge Function, New Brief Urges

Europe’s landscapes are quietly losing one of their most valuable natural capacities: the ability to act like a sponge. Healthy soils, intact wetlands, functioning floodplains and well-structured forests absorb rainfall when it is abundant, store it in the ground, and release it slowly through dry periods. When that capacity degrades, water that once soaked into the ground instead races off hardened surfaces, swelling rivers during storms and leaving catchments parched when the rains stop. A new joint policy brief from three EU-funded research projects now argues that restoring this so-called sponge function should be woven directly into the implementation of European Union policies, rather than treated as an afterthought in environmental planning.

The brief, titled Achieving Better Implementation of EU Policies by Restoring the Sponge Function, was produced by the sister projects SpongeBoost, SpongeWorks and SpongeScapes, all funded under the European Union’s Horizon Europe Research and Innovation Programme. Together, the three initiatives combine policy guidance, scientific evidence and real-world demonstration sites to advance the concept of sponge landscapes across Europe. Their central message is that the coming 2026 to 2027 window of EU policy processes represents a strategic opportunity to embed catchment-scale water retention measures into the legal and financial architecture of the Union, and that failing to do so would squander a low-cost chance to build resilience against both floods and droughts.

The scale of the underlying problem is stark. According to the policy brief, Europe has lost around 70 percent of its wetlands, roughly 50 percent of EU peatlands are degraded, and 70 percent of EU soils are not healthy. Each of these figures translates directly into reduced water retention. Drained peatlands release their stored carbon and water instead of holding both; compacted or eroded soils shed rainfall rather than infiltrating it; and lost wetlands no longer buffer the pulses of water that storms deliver to river systems. The combined effect is a continent in which droughts bite harder and floods run more destructive, a pattern that climate change is expected to intensify as precipitation becomes more variable and extreme.

The scientific logic behind sponge restoration rests on hydrological connectivity. Soils, wetlands, forests, grasslands and agricultural areas within a river catchment do not operate independently; they function as one interconnected water system. Water that infiltrates high in a catchment feeds groundwater and base flows downstream, while water that is blocked from infiltrating becomes surface runoff that must be carried by channels and flood defences. This is why the brief insists that sponge restoration must operate at the scale of entire landscapes and river catchments rather than through isolated, site-specific interventions. A single restored wetland or a patch of improved soil can deliver local benefits, but the hydrological payoff multiplies when measures are coordinated across the full upstream-to-downstream gradient.

Importantly, the authors are careful about what sponge restoration can and cannot achieve. The brief states plainly that restoring the sponge function is not a standalone solution for extreme weather events. A severe storm can overwhelm even a well-functioning landscape, and a prolonged drought can exhaust even deep stores of soil moisture. Instead, the brief positions sponge restoration as a low-regret, catchment-scale approach that complements other measures. The term low-regret is significant in policy terms: it describes interventions that deliver benefits across a wide range of future scenarios, so that decision-makers do not need precise predictions of how climate extremes will unfold before committing resources. Water retention, biodiversity, water quality and climate adaptation benefits all accrue regardless of which extreme event arrives next.

Political momentum for this agenda has been building. As support for nature-based solutions continues to grow, policymakers are increasingly recognising the need to enhance the natural sponge function of European landscapes, a shift reflected in the 2025 European Water Resilience Strategy. The strategy’s proposed Sponge Facility, highlighted in the brief, is conceived as a cross-directorate investment and delivery mechanism that would link finance, planning and monitoring for sponge measures. The policy brief argues that operationalising this facility is one of five priority actions needed to move sponge restoration from concept to implementation, giving it a durable institutional home rather than leaving it dependent on scattered project funding.

The five priority actions set out in the brief form a coherent implementation roadmap. First, sponge restoration should be embedded as a low-regret, catchment-scale solution in River Basin Management Plans and Flood Risk Management Plans under the Water Framework Directive and the Floods Directive, the two legal pillars that already structure water management across EU member states. Second, targeted sponge measures should be included in the consultation and planning processes related to implementation of the Drinking Water Directive, connecting source-water protection with upstream landscape management. Third, the European Water Resilience Strategy’s Sponge Facility should be operationalised as the cross-directorate mechanism described above. Fourth, EU instruments including the Common Agricultural Policy, Cohesion Policy, LULUCF and the Nature Restoration Regulation should be aligned around catchment-scale sponge targets rather than sector-specific interventions. Fifth, measurable sponge-function indicators covering soil health, water retention, flood attenuation and drought buffering should be introduced into EU monitoring and reporting systems.

The fourth and fifth actions deserve particular attention because they address a chronic weakness in European environmental governance: fragmentation. Farmers are subsidised through one policy instrument, nature restoration is mandated through another, and water quality is regulated through a third, with limited coordination between them. A catchment whose peatlands are rewetted under a restoration regulation while its upstream agricultural soils continue to be compacted under business-as-usual farming will never recover its full sponge capacity. By aligning the Common Agricultural Policy, Cohesion Policy, land use and forestry accounting, and nature restoration rules around shared catchment-scale targets, the brief proposes to make individual funding streams reinforce one another. Measurable indicators, meanwhile, would make progress visible and accountable, allowing the effectiveness of sponge measures to be tracked in the same way that emissions or water quality are currently monitored.

The potential co-benefits extend well beyond flood and drought risk. Restored wetlands and peatlands filter nutrients and sediments from water, improving quality for downstream users and reducing treatment costs. Rewetted organic soils stop emitting the carbon that drainage releases, contributing to climate mitigation alongside adaptation. Habitat restoration for wetland species follows almost automatically from hydrological recovery, supporting biodiversity commitments under the Nature Restoration Regulation. This bundling of benefits is precisely what makes sponge restoration attractive from a policy economics perspective: a single intervention portfolio addresses multiple directives and strategies simultaneously, and the low-regret framing means that even under uncertain climate futures the investment retains its value.

What happens next will depend on whether the recommendations are picked up in the 2026 to 2027 policy cycle that the brief identifies as decisive. The three projects behind the publication, SpongeBoost, SpongeScapes and SpongeWorks, continue to receive funding from Horizon Europe, with SpongeScapes and SpongeWorks additionally supported by UK Research and Innovation and HM Government. Their combined evidence base, spanning policy analysis and on-the-ground implementation, is intended to give national and EU decision-makers the technical justification for acting. If the five priority actions are adopted, Europe’s rivers, soils and wetlands could begin recovering the water-buffering capacity lost over centuries of drainage and land-use change. If they are not, the continent will continue to pay for that lost sponge function through emergency flood defences, drought relief and degraded water supplies, costs that the brief suggests are far higher than the price of restoring the landscape’s natural capacity to hold water in the first place.

Subject of Research: Restoring the natural water-retention sponge function of European landscapes through aligned EU policies

Article Title: New policy brief outlines how EU policies can better support sponge restoration

Article References: New policy brief outlines how EU policies can better support sponge restoration. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: sponge restoration, EU policy, water resilience, flood risk, drought, wetlands, soil health, nature-based solutions, river catchments, Water Framework Directive, Horizon Europe, climate adaptation