Report on the work of boulis - Djilasse, Senegal

Work on the overburdening, backfilling and compacting of three boulis (rainwater retention ponds) took place in the Fatick region from 27.03.2023 to 21.04.2023.

The boulis were built in three villages in the Siné Saloum region of central Senegal as part of the "A kop allé no maag olé - La Forêt de la Mer" project, led by IRHA and its Senegalese partners, APAF and Oceanium.

The construction of these structures is an ongoing, evolving and living process. Improvements are likely to be incorporated over the years, but also according to the responses of the ecosystem and the communities to the work.

Most of the work is undertaken by the local population or workers from the local community to encourage ownership, understanding and maintenance of the structure.

For example, the cleaning of the grass cover was carried out by the population and was followed by a collective manual overburdening. However, after a difficult start and a closer examination of the soil, it turned out that the environment was drier than previously thought and the workers could only manage to dig out the upper crust with difficulty. Following consultation with the population, it was decided to use a mechanical shovel to facilitate the work and to carry out the excavation and backfilling.

As a result of this work, we have increased the volume of rainwater storage in the area by approximately 500m3. To this volume, we must also add the ambient humidity generated by the permanent water point and its vegetation, the so-called "green" water contained in the vegetation cover and the trees adjacent to the boulis, as well as the water contained in the soil. The boulis thus becomes a real oasis, an anchor for the restoration of the landscape and ecosystems of the Siné Saloum.

Aziz Konaré