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Infiltration trenches in Kungsbacka, Sweden

Summary
Flow-weighted sampling was performed at the inlet and outlet of one of the infiltration trenches beneath the parking lot of a supermarket in Kungsbacka, south of Gothenburg. Monitoring ran from April–June 2012 and five storm events were originally analysed. The trench is part of a larger system serving the Maxi ICA site (≈3.1 ha) with three subsurface macadam trenches; the monitored “trench 1” had ~176 m³ storage with a permitted outflow of 6.17 L s⁻¹ (site cap 15 L s⁻¹). Runoff passes an oil separator and then discharges to stormwater ponds located between the car park and the Björkris residential area (toward Björkrisån/Kungsbackaån). Reported pollutant removals were high for TSS and metals and moderate for nitrogen, alongside clear flow attenuation. A subsequent peer-reviewed paper expanded the dataset to seven events and confirmed these trends. More recent municipal stormwater guidance (2023) highlights the Björkris/Hede ponds as part of the local network; while this corroborates the downstream arrangement, publicly available sources do not document the current maintenance or operational status of the specific trenches.
Last update
2025

Constructed wetland with reed bed filters near Reims, France

Summary
The intensive urban development of the Bezannes joint development zone (ZAC), near Reims, has led to the artificialization of 172 hectares of land, along with a growing need for stormwater management. Vegetated swales were implemented in the southern part of the area, while in the north, stormwater is collected and directed to a facility that includes an artificial wetland, an artificial lagoon, and a reed bed filter.
The construction of this facility, initiated by the Greater Reims Urban Community (project owner) and Sinbio (project manager), aimed to incorporate a nature-based solution to manage stormwater inflows upstream of the Muire River, improve the quality of discharged water, and create a 5-hectare natural space that would benefit both local residents and biodiversity called Parc de la Roselière.

This project illustrates a shift from traditional civil engineering to ecological engineering, combining water regulation, pollution control, biodiversity enhancement, and public amenities.
Last update
2015

Recovery of dried out communities in Slovakia

Summary
Integrated rainwater retention was applied to recover degraded landscapes and local climate in north-eastern Slovakia, using small check dams, retention ponds, rain gardens and re-cultivated logging roads. Coordinated by People & Water (Ľudia a voda) and co-financed by the LIFE programme (LIFE11 ENV/SK/001019), the project worked across the Ondávka micro-region (Humenné district; eight municipalities). Implemented from August 2012, it ended early in May 2015 after loss of co-financing. By closure, 1,148 small barriers, 7 rain gardens and ~1 km of logging roads had been built or re-profiled; planned fishponds were cancelled. Local reporting indicates the measures reduced flood peaks during intense storms in 2013–2014 and were estimated to enhance the “small water cycle” by ~140,000 m³/year. The project also created short-term jobs (e.g., 56 unemployed people engaged in 2013 via the Humenné Labour Office). Since 2015, similar water-retention approaches have been incorporated into regional plans (e.g., the Košice Region’s 2021–2030 landscape and river-basin restoration programme) and referenced in national flood-risk planning updates (2024) covering the area.
Last update
2025

Reconstruction within the Sur Fen Nature Reserve, Slovakia

Summary
Reconstruction of dams and sluice gates, blocking of drainage ditches and creation of a hydrological network to route water from the Little Carpathians through the Šúr Fen National Nature Reserve (near Svätý Jur), funded by the LIFE programme (LIFE03 NAT/SK/000096). The works were prepared and initiated in 2003–2007 and complemented the intake built in 2001 on the Šúrsky Canal (rkm 10.197), which diverts water into the reserve when canal flow exceeds Q5 (up to ~7.4 m³/s). The Danube Flood Risk Management Plan (2015) describes a system of inverted siphons, canals and an aqueduct enabling year-round supply and water level management inside the fen. Project materials detail the refurbishment of control structures (e.g. on the Blahutov Canal), conversion of a drainage canal to irrigation, and raising water levels in the Čierna Voda to limit peat drawdown; interpretation and a nature trail were also delivered.
Since 2017–2018, management has reintroduced wood-pasture grazing in the Panónsky háj (southern part of the reserve) with local partners. Recent monitoring (2023–2024) reports marked increases in wild bee abundance in restored areas, indicating positive ecological response.
Last update
2025

Ezousas artificial groundwater recharge of treated effluent in Cyprus

Summary
Along the lower ~8 km of the Ezousa riverbed near Paphos, a MAR/SAT scheme uses the aquifer as a natural reservoir: tertiary-treated effluent from the Paphos WWTP is conveyed to infiltration ponds in the riverbed, naturally filtered, stored and later abstracted for irrigation. Built in 2003, the system comprises five pond groups (23 basins in total) supplied by a 500-mm main, with a design capacity of roughly 9,000–12,000 m³/day. Annual recharge increased from ~1.63 Mm³ (2004) to 4.44 Mm³ (2015); WDD’s assessment (2006–2015) reported no adverse effects attributable to recharge, with only occasional chlorination by-products detected downstream. Research at the site indicates slight attenuation of nutrients and notes copper in groundwater exceeding EPA standards, likely of geogenic origin. Today, all reclaimed water produced in Paphos is routed to the Ezousa aquifer and then pumped and distributed for irrigation through the government network.
Since 2021, real-time sensors (water level, EC, temperature) linked to the INOWAS platform complement routine sampling, strengthening operational control.
Last update
2025

Green roofs in Geneva, Switzerland

Summary
Located in Geneva, this case describes the long-running programme of green roofs at the University Hospitals of Geneva (HUG). The first roof (≈0.55 ha, 1993) was designed to retain ~30.25 m³/day; compared with a conventional roof it retains about 60% of runoff, while also recreating urban habitat. Since then the scheme has expanded: in 2023 HUG added 2,835 m² on three buildings (Maison de l’enfance et de l’adolescence, Adult Emergency extension, GIBOR). After a full inventory in 2024, HUG reports more than 11,900 m² of vegetated roofs across its sites.
Local monitoring in Geneva (TVEG/HEPIA) confirms hydrologic benefits beyond the original design assumptions: storm peaks are delayed and attenuated, with up to ~75% reduction for a summer event (and ~48% in winter), and a larger share of water returned by evapotranspiration (~61%) relative to a reference roof. The Canton’s “Nature en ville” programme documents biodiversity outcomes and provides up-to-date technical guidance; at cantonal level, compliant green roofs can lower stormwater fees.
Last update
2025

Restoration of the Vesselina river, Bulgaria

Summary
WWF’s Danube-Carpathian Programme, together with residents of Mindya (Veliko Tarnovo), reconnected the Veselina River to a former meander near the village. When the bend was cut off in the past the channel incised by ~150 cm, so a low sill was built (works 2007–2008) to raise water levels and route flow back into the old course.
The reconnection now creates slower, warmer waters that support breeding habitat for fish and birds and add retention during high flows.
Project timeline: initiated 2005, works completed April 2008; total cost ≈ €76 k funded by WWF and the DOEN Foundation. The reach lies on WFD water body BG1YN130R029, classified as HMWB.
In May 2012 the site was legally designated the “River Veselina” Protected Area, announced by the Ministry of Environment and Water on the International Day for Biological Diversity; the designation explicitly includes the restored meander. The protected area covers about 98.6 ha between Kapinovo and Mindya.
Since designation, local biodiversity work has documented amphibian and reptile assemblages within the protected area, adding evidence of habitat value.
Last update
2025

Restoration of the Ernz Blanche river, Luxemburg

Summary
The Ernz Blanche (Luxembourg) river restoration sought to undo channelisation that had uniformised the river and increased downstream flooding. It relocated the watercourse into the thalweg, widened and/or raised the bed, re-meandered the channel, backfilled the former bed, restored adjacent streams, redesigned pipeline connections, and redeveloped areas around hydraulic structures.

After the 2002 feasibility, major works were delivered in 2010–2011 on the Koedange–Supp reach (~5 km), reducing flood peaks at Larochette (–3.8 m³/s; –25 cm) and creating ~110,000 m³ of storage (project cost ≈ €1.52 m). In 2016, longitudinal continuity downstream at Ernzen was restored via a pool-type fish pass at Wehnschelt and a rough ramp at Milleboesch. The project area has also been tied into the PC5 cycle path and Natura 2000 management.

Under Luxembourg’s 2021–2027 Flood Risk Management Plan, additional riverbed restoration and space-for-river measures are listed/advancing on several reaches, incl. 417 m at Larochette; 1,102 m along CR119 at Ernzen (in implementation); 2,739 m at Altlinster; and 629 m at Medernach. Recent 2025 decisions cover local flood-protection works and targeted sediment removal in Larochette, while continuous hydrometric monitoring at station “Larochette / Ernz Blanche” supports ongoing management.
Last update
2025

Germasogeia riverbed artificial groundwater recharge in Cyprus

Summary
Germasogeia (Amathos) River crosses Yermasoyia municipality near Limassol. The measure, launched in 1982, restores natural purification and recharge of the Germasogeia alluvial aquifer, processes disrupted by the upstream dam. It works by gradual reservoir releases while maintaining the riverbed’s high transmissivity. Monitoring includes flows at four weirs, groundwater levels in observation wells and coastal salinity; pumped water supplies Limassol and nearby communities.

More recently, the Water Development Department (WDD) and academic partners developed and validated optimisation models (2016–2019) on WDD data to keep target water tables with lower release volumes, formalising the conjunctive-use operation. In 2015, a 1–1.5 m concrete weir on the Germasogeia was removed within a hydromorphological restoration project; it had reportedly been built to enhance recharge. In parallel, desalination capacity serving Limassol (e.g., Episkopi, Vasilikos, and new/expanded units) now provides a major share of potable supply, easing pressure on the aquifer in dry years. In the wider district, WDD also operates a separate MAR scheme at Akrotiri (17 recharge ponds, since 2016) using tertiary-treated effluent against seawater intrusion.

Overall, Germasogeia remains a long-running SAT/MAR scheme, now embedded in a diversified water-supply system and supported by modelling and river restoration actions.
Last update
2025

Revitalisation of the Borova stream, Czech Republic

Summary
Restoration of the length of the Borova stream, increased by 6.3 km a shallow meandering stream bed, where sections of speedily running water alternated with sections of a slow stream were created, financed by the Ministry of Environment of Czech Republic.
Today this project is still relevant and effective, although it would need reconstruction in places.
Last update
2025