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Aquifer recharge with highly polished treated effluents. With a high population density and almost no surface waters, Malta faces chronic over-abstraction: total demand exceeds the sustainable yield of naturally renewable freshwater. Demand comes from domestic and agricultural uses (domestic peaks can exceed agriculture during the tourist season). Groundwater quality is threatened by nitrates and seawater intrusion.

A pilot at Bulebel (2010–2013, MEDIWAT) tested injection of ultra-polished reclaimed water via an injection well under strict quality monitoring. Since then, Malta has pursued MAR within a broader strategy: the EU MARSOL demonstrator (2013–2017) designed an injection-well barrier near the Malta South plant (Ta’ Barkat) to counter seawater intrusion; the national New Water programme is expanding reclaimed-water production (~7 Mm³/yr capacity) and distribution for agriculture, creating seasonal surpluses that can supply MAR. Under the LIFE-IP RBMP (2021–2027), Action C8 is developing a pilot MAR scheme in the Pwales coastal groundwater body using reclaimed water when irrigation demand is low; a 2024 hydrogeological study characterised Pwales to support MAR design.

Measures to attenuate runoff were installed in the small Belford catchment, in northeast England, in order to reduce the risk of flooding to the village downstream. The installations involved a network of small measures to capture and delay runoff from the rural catchment, including detention basins and overland flow features, as well as sediment capture measures to improve water quality.

However, since the implementation, the features were not maintained by the landowner, and have been then decommissioned. The measures that were implemented are no longer functional.

This flagship of the national Room for the River programme at Nijmegen set back the dyke at Lent and excavated the Spiegelwaal side channel, creating the Veur-Lent island and an urban river park that can take additional flood flow from the Waal. Completed in 2016, the scheme achieves about 35 cm lower design water levels—exceeding the original 27 cm target—and safely diverts high flows; the channel first overtopped its threshold in February 2016. Since delivery, the area has been reshaped as public space with new bridges and intense recreational use. In 2022 the city decided not to build housing on Veur-Lent, keeping the island largely as parkland (with limited facilities), while planning proceeds nearby. The Spiegelwaal now serves as a pilot in “Connected River” to balance flood safety, water quality and heavy leisure demand; bathing advice has at times been negative due to bacteriological risks. Funding came mainly from the State, with total costs reported at about €351 million.

This project combined several natural water retention measures: restoration of meadows and pastures, reduced tillage, reduced stocking density, and wetland restoration . Located in north-west Germany (Weser basin, DE4000), it was funded under the LIFE Program and aligned with the WFD, Habitats, and Birds Directives. Since 2017, over 30 ha of wetlands have been restored, and a reed polder (>80 ha) is being developed to reduce phosphorus loads. Additional river restoration measures have been implemented in the Hunte and Elze catchments. The project involved a wide range of stakeholders, including conservation bodies, water managers, farmers, and local NGOs. It successfully increased meadow bird populations and fostered constructive stakeholder cooperation. Recent efforts also include fish removal and a shift from technical to nature-based solutions, with key goals targeted for 2027.

The Holter-Hammrich project combined several natural water retention measures: floodplain restoration, meadow and pasture rehabilitation, and reduced tillage. Located in north-west Germany within the Weser river basin (DE4000), it supports Lower Saxony's otter and wetlands protection programs and contributes to WFD goals. Since its implementation, the 240 ha flood retention polder—activated in 2011—has enhanced flood protection and become a key habitat for over 60 bird species and other wildlife, including the returning European otter. It now also serves educational and recreational purposes, with a 7 km nature trail and observation points. The project stands out for its integration of ecological, hydraulic, and public engagement goals, achieved through multi-stakeholder cooperation involving environmental agencies, water managers, local authorities, and farmers.

Originally implemented under the UNDP/GEF Tisza MSP, the measure rebuilt an existing floodgate at the confluence of a drying bypass channel and the Žiarovnický stream in the Senné depression (Bodrog basin). The gate enables gravity supply to the Senné fishponds NNR in dry periods and during floods, and reduces discharges to the Stretávka pumping station. It was financed by the Global Environment Facility and delivered by Global Water Partnership Slovakia with local authorities.
Since then, complementary works have expanded upkeep and control of the small-hydraulic network. A LIFE project for the Senné & Medzibodrožie SPAs restored water-level control via gates/sluices and dyke repairs, improving the hydrological regime around the ponds and Ostrovik meadows.
Most recently (2020–2023), SOS/BirdLife Slovakia repaired/maintained ~1.69 km of dikes and ~2.17 km of supply canals and improved the water regime across ~814 ha; managers now manipulate existing stavidla annually to sustain wetland habitats. These actions and targets are embedded in the 2022 Care Programme for the SPA.

In the 1950s–60s, the Alzette floodplain was straightened for intensive agriculture, reducing water retention and ecological value. At Dumontshaff (Schifflange), the project set out to restore river-floodplain functioning (frequent overbanking, wetland habitat recovery) and to shift meadows to extensive management (late mowing, no fertiliser or biocides). After feasibility and land reallocation, works returned the river to its natural thalweg, widened and raised the bed, reactivated a secondary arm, and enabled floodplain and wetland restoration.
The main works on the Dumontshaff–Lameschmillen reach were completed in 2005 within a ~1.4 km section of the Alzette (plus ~600 m of the Kiemelbaach), with thalweg relocation and bed re-profiling; a dedicated project page reports a cost of ~€920k (excl. VAT). The wetland was formally designated as a National Nature Reserve in May 2023. Management now relies on year-round extensive grazing by Galloway cattle and water buffalo over >40 ha, and a nature trail (~4.4 km, 24 stations, observation tower) supports public access. Ecological outcomes include the return of Greater Spearwort (Ranunculus lingua) in 2009 and regular breeding of White Stork in the restored valley. Nearby, further renaturation on the Kiemelbaach was undertaken in 2020, while broader Alzette restoration continues upstream in separate projects.

The River Tolka runs through Dublin, Ireland. In Tolka Valley Park, a suite of measures was implemented to slow flood flows, reduce pollution and support wildlife: runoff retention ponds, bank re-profiling to slow flows and prevent erosion, riparian tree planting, and integrated constructed wetlands (ICWs) to improve water quality (once leachate from a former landfill was detected). Later, a fountain and barley-straw bales were used to limit algal blooms, and invasive plants were managed with biodegradable matting and planting.

Built in two phases (1999–2001; 2009–2013 Greenway), the ICWs treat polluted stormwater from the Finglaswood Stream before it enters the Tolka. Since 2019, sources confirm the site remains operational and biodiversity-rich (reed/sedge swamps, breeding mute swan; spawning common frog). Dublin City Council reports active invasive-alien-species control in the park, and the Luas Finglas project includes remediation/mitigation works to the existing ICW, with design notes that low flows are routed through the ICW and higher flows bypass to the river. Governance/cost snapshots add context: the first ICW was relatively low-cost (~€40k) while the 2009–2013 phase exceeded €3 m. Tolka Valley Park is now ranked among Dublin’s most important biodiversity sites due to the river and wetland chain.

The action, led by the State Nature Conservancy of the Slovak Republic with NGO partners and funded by LIFE and national sources, set out to restore the favourable conservation status of breeding and migratory Birds/Habitats Directive species in the Senné (Senianske rybníky) and Medzibodrožie SPAs by improving key wetland habitats. Since then, conservation has continued under follow-on projects and plans. In Medzibodrožie, LIFE AYBOTCON (2011–2018) restored c.280 ha of water biotopes, created buffer zones, modified 1 770 m of power lines to reduce collisions, purchased land, and improved occurrences of bittern and ferruginous duck. In Senné, LIFE IPORSEN (2017–2027) focuses on hydrological restoration - repairing four sluice gates, 1.6 km of channels and 1 km of dykes, and reconnecting oxbow arms - alongside reedbed/grassland management, creation of nesting sites and small visitor infrastructure.
Both SPAs now have government-approved management plans for 2022–2051 that set long-term objectives, measures and indicative budgets for water-regime restoration and habitat management.
In 2023, IPORSEN works at Senné included repairing dikes and reconstructing the supply canal to secure water levels across the pond system.

In the framework of the large-scale nature conservation project "Lenzener Elbtalaue", a dyke along the river Elbe (in Germany) has been relocated. This created a new retention area with a diverse floodplain, including alluvial forests, half-open pasture landscapes and other typical habitats of lowland floodplains. With 420 ha it is the biggest application of this type of measure in Germany so far. The project successfully combines flood protection and nature conservation objectives. Since the cutting of the old dyke in 2009, the measure could proof its effectiveness during several high water events.
The specific measures applied include:
- Construction of a new, 6.1 km long dyke which has been shifted backward up to 1.3 km
- Opening of the old, 7.2 km long dyke, situated close to the river, in sections of 200-500 m length
- Planting of 160 ha of alluvial forest, with further 130 ha of succession areas for alluvial forests
- Establishment of half-open pasture landscapes on 85 ha
- Profiling of 45 ha of flood channels in the area concerned by the relocated dyke
- Implementation of a land re-organization process in order to make areas available for the project