Constructed Wetlands
Nature-based treatment that turns neighbourhood wastewater into water people can reuse, run by the community with the local water utility.
Wastewater with nowhere safe to go
Growing towns are building condominium blocks faster than sewers and treatment plants. Their wastewater often reaches drains, streets and rivers untreated, and conventional treatment plants are too costly and energy-hungry for many towns to build and run.
We asked a different question: what is the simplest system a community and its water utility can build, afford and operate themselves?
Let plants, gravel and bacteria do the work
A constructed wetland passes wastewater slowly through a lined bed of gravel planted with wetland plants. Bacteria living on the roots and gravel break down the pollution. Most of the flow runs by gravity, so there is little or no power to pay for and no chemicals to buy.
- Low running costs: little or no energy, simple routine maintenance.
- Water to reuse: in Adama, treated water is drawn with a hand pump for toilet flushing and vegetable gardens.
- A green space, not a plant room: the wetland becomes part of the neighbourhood.
- Climate-smart: little or no electricity to fail, treated water for dry seasons, and far less methane than wastewater left in open drains.
Three wetlands in Adama and Shashemene
The first two wetlands were built with the Shashemene Water Utility for condominium estates in Shashemene, in 2021 and 2022. The third opened in the Dembela neighbourhood of Adama on 9 October 2024, treating wastewater from three condominium blocks for about 700 residents, who manage it together with the Adama Water Utility. Together the three wetlands serve about 1,134 residents.
“It has so many benefits and the place looks beautiful.”
Fikerte, resident of Shashemene (quoted by WASTE)
The Adama wetland was inaugurated with community elders, the State Minister for Water Supply and Sanitation and Dutch partners, and is now a reference for nature-based sanitation in Ethiopian towns.
In the news
- 700 happy residents thanks to new wetland in Adama, Ethiopia Dutch Water Authorities
- Celebrating Constructed Wetland Day in Ethiopia World Waternet
How the wetlands were built
Built step by step with local contractors and labourers: excavation, a sealed liner, layered gravel, distribution pipes and plants grown in a nursery.
