Mobilisation of water resources for irrigation via MEREN

Recovering wastewater from sewage treatment plants to irrigate and secure agricultural production on Réunion

As part of the MEREN operation (mobilisation of water resources in the eastern and northern micro-regions), the Réunion departmental council has commissioned Artelia to design irrigation networks and a project to recover treated water from the Grand Prado wastewater treatment plant.

The project involves the creation of a 20 km water main, combined with 6 km of transfer galleries, 30,000 m³ of reservoirs and 24 crossings.

5,000 ha

of irrigated land

500 ha

irrigated by reuse of waste water

30,000 m3

of additional réservoirs


With its tropical climate, Réunion has no shortage of water, even if the island’s abundant rainfall is unevenly distributed. It is rather the storage and distribution infrastructures that are insufficient, particularly in the highlands and the northern and eastern regions. The Meren irrigation programme (mobilisation of water resources in the Eastern and Northern micro-regions) is aimed precisely at remedying this deficiency.

It will irrigate more than 5,000 hectares of farmland currently lacking in water infrastructure. It also includes a project to reuse wastewater from the Grand Prado wastewater treatment plant to meet agricultural needs, in particular the irrigation of more than 500 hectares of sugar cane. Artelia is in charge of the design studies of this project…

Artelia is project manager for the design of this project, which involves building:

  • A water treatment plant at the sewage treatment plant outlet, with a flow rate of 1240 m³/h, in order to bring the water into compliance with European regulations on water intended for irrigation purposes; Class A, the most stringent category, has been selected by the project owner, and will even allow the irrigation of food crops eaten raw, where the edible part is in direct contact with the recovered water, as well as weeds eaten raw.
  • Over 200 kilometres of irrigation networks (DN 700 to 63)
  • Two delivery stations of over 300 kVA