Solution 01
Pond stream pond treatment system
At Manlleu, ponds, a vegetated stream, floating macrophytes and microbial biofilms naturally remove nutrients and ammonium from treated wastewater.
WaterMed Hub 3
Drought
Water scarcity and drought
Origin Lab
Osona, Catalonia, Spain
Territory
Osona is a rural–urban territory in the Ter River basin with a strong agricultural and industrial economy. Its water supply depends heavily on the Ter River, while treated wastewater becomes increasingly important for maintaining river flows during droughts.
Water and environmental challenges
- Water scarcity and dependence on a single surface-water source.
- Pollution from agricultural nitrates, ammonium and trace compounds.
- Degradation of rivers, riparian habitats and aquatic biodiversity.
Objectives
- Improve wastewater quality before it returns to local rivers.
- Protect downstream drinking-water sources and ecosystems.
- Assess the expansion of natural tertiary treatment systems.
Nature-Based Solutions
Solution 02
Green filter and constructed wetland
At Centelles, a green filter and wetland system treat the full wastewater discharge before it enters the Besòs River, supporting downstream water quality and ecological flows.
Implementation Lab
Hurghada, Egypt
Territory
Hurghada is a hyper-arid coastal city with no natural freshwater sources. Its water supply depends on desalinated seawater and water transported over 500 km from the Nile, while the area also provides an important habitat for migratory birds.
Water and environmental challenges
- Extreme water scarcity and dependence on distant water sources.
- Limited wastewater reuse due to inconsistent effluent quality.
- Flash-flood risk and loss of habitats for migratory birds.
Objectives
- Improve treated wastewater quality and increase safe reuse.
- Reduce flash-flood impacts through additional water retention.
- Restore wetlands, vegetation and habitats for local biodiversity.
Nature-Based Solutions
Solution 01
Constructed wetlands and retention ponds
Former stabilisation ponds will be rehabilitated as constructed wetlands, treating wastewater while also retaining runoff during flash floods.
Solution 02
Treated-water reuse and woody forest restoration
Tertiary-treated water will irrigate the neighbouring woody forest, supporting afforestation, habitat restoration and more efficient use of local water resources.