UNDP-GEF Kura II: Advancing IWRM Across the Kura River Basin

Awareness Raising meeting about the Constructed Wetland in Hajigabul

On December 2, 2019, the UNDP-GEF Kura II Project has organized an awareness raising meeting on the Constructed Wetland to be built in baby Hajigabul Lake in Shirvan.  

Project is building a Constructed Wetland for the treatment of household wastewater generated by local communities in part of baby Hajigabul Lake in Shirvan. This wetland will be able to treat a wastewater flow of 3 liters per second.  
The wetland will reduce pollution in the lake using the same processes occurring in nature, improving the environment of Baby Hajiqabul Lake and of the Kura River Basin.

Under the Kura II project Component 3, Output 3.3. River Restoration Projects for improved ecosystem health using integrated flow management, the building of the Constructed Wetland for the treatment of household wastewater generated by local communities located in an area of baby Hajigabul Lake in Shirvan.

This constructed wetland will be constructed to treat part of the polluted water of a small open ditch that collect untreated water to the Baby Hajigabul lake. The treatment wetland is aimed at reducing the pollution of the lake by recurring to sustainable and replicable treatment methods capable to treat different type of pollution sources before their discharge into the environment.

The proposed constructed wetland treatment plant lay-out will be composed of single stage with the Free Surface Flow System (FWS) which is fully vegetated with emergent plants (local reeds and canes) with a total surface of the bottom is 4350 m2 and a total surface of the water is 5480 m2. The constructed wetland will be able to treat effluent flow of about 3 l/s (260m3/day) derived from the sewage channel by a pumping station. The design of the constructed wetland assumes that 2000 person discharge untreated wastewater into the Baby Hajigabul Lake.

The expected performance of the constructed wetland treatment plant will ensure the removal rate greater than 70% for BOD, 75% for TSS, 20-50% for total nitrogen, and 90% for disinfection.  

About the Constructed Wetlands

Constructed Wetland are nowadays one of the most worldwide diffused technology for the wastewater treatment; they are Nature Based Solutions (NBS) and their functioning principles are based on the biological, physical and chemical processes that occur in natural wetland, even if the CWs (especially subsurface types) are engineered  systems studied and monitored since the end of ‘70.


  • High treatment efficiency in organic, nutrient and bacterial removal
  • Higher tolerance to oscillation in flow and pollutant loads
  • Low investment cost and low maintenance requirements compared to traditional technological treatments
  • Low or no Energy consumption
  • the best integration in the urban and natural landscape
  • No odors or mosquito proliferation problems (especially in submerged flow system – HF and VF – where the sewage never enter in contact with the atmosphere)