Lake Manzala Engineered Wetland: Treating Drainage Water Before Egypt's Largest Lagoon

Built from 2001 with a US$4.5 million GEF grant alongside UNDP and Egyptian government co-financing (total project cost about US$11.1 million), the Lake Manzala Engineered Wetland is a roughly 100-hectare constructed wetland southwest of Port Said. It intercepts part of the polluted Bahr El Baqar drain, passing it through vegetated treatment cells to trap sediment and reduce pollutant loads before the water reaches Lake Manzala, Egypt's largest coastal lagoon.

Project documentation and follow-up hydrodynamic and water-quality studies report measurable improvements in water and sediment quality attributable to the wetland, treating roughly 25,000 m3/day; treated effluent is used to rear juvenile fish for restocking the lake and supplying other aquaculture.

Lake Manzala's own commercial fish yield, once over half of Egypt's total catch in the 1980s, had fallen to around 11% of historical levels by 2020 because of basin-wide eutrophication, heavy-metal pollution and habitat loss that a single 100-hectare facility cannot reverse -- illustrating both the value and the limits of treating just one drain among many feeding a heavily stressed water body.