Nature-based Solutions on existing infrastructures for resilient Water Management in the Mediterranean

Oued Righ channel, Algeria

FWC-NbS 5: Surface artificial channels (Type C)

Location:  Touggourt, Algeria

Climate: Arid climate

Area: 600 Ha

Objectives: Improve storage and efficiency of artificial distribution systems, mitigating pollution and environmental degradation.

Challenges: Droughts and water scarcity; water quality; stagnant water; air pollution; silting; evaporation; soil degradation; biodiversity loss; erosion; high water levels; groundwater level decrease

Description: Oued Righ channel is located in the South East of Algeria, crossing 12 municipalities of two states on a stretch of 150 km, ending in the natural lake Chott Merouane, part of one of the most important Algerian wetland complexes. It passes by the middle of palm groves and near oasis dwelling areas and offers a unique ecosystem essential for their inhabitants. The southern part of the channel has been dug, while the northern part has natural origin. The channel collects water from the few annual storms and drainage from agriculture irrigation. In this region, the wastewater treatment plant (WWTP) treats just 20% of urban wastewater, while the rest is discharged directly into the Oued Righ channel. The channel also plays an important role in the drawdown of the water table. Maintenance work has been carried out to lower the water table, protect the environment and reshape channel banks. 

  • Agriculture: The main crop is date palm and is often associated with underlying crops like market gardening, condiments and some fruit trees scattered in palm groves.
  • Communities: The economic life depends mainly on Palm groves agriculture.
  • Water policies: Water Law n°05-12 of August 04, 2005.
  • Data: There is data on biodiversity and salinity levels in Oued Righ valley.

NbS

Constructed Wetland​

In Case Study 5, it is planned to install a pilot-scale system designed to offer secondary treatment for domestic sewage and tertiary treatment for water from the Touggourt activated sludge plant. The system will combine different types of CW units. This combination will improve the quality of the water discharged in the Oued Righ channel, and will improve the functionality of the Wastewater Treatment Plant and reduce the maintenance costs. Currently, the treatment capacity of the existing Wastewater Treatment Plant is 20% of the city’s wastewater.

Riparian Buffer

The both banks of the Oued Righ canal will be revegetated with macrophyte species. The Macrophyte species can also be present in the bed of the canal, playing the role of a natural purification system. The combination of the existing grey infrastructure (Gabion wall) with the natural infrastructure (canal banks revegetation) in a hybrid approach, will also help to protect the existing bridge.