COMPARATIVE ANALYSIS OF WATER SUPPLY PIPELINE INSTALLATION METHODS IN THE PERIPHERAL NEIGHBORHOODS OF BAMAKO: TECHNICAL CHALLENGES AND SUSTAINABLE SOLUTIONS

Safe drinking water is still a major challenge for fast-growing African cities. In Bamako, water networks regularly suffer from leaks, pipe breaks and joint failures that degrade service quality. This study looks at the pipe laying methods used in Lot 1 of the Kabala project, which involves building 12 km of new networks and commissioning 93 km of existing networks in Communes I and II. To do this, we analyzed the Tender Documents, the technical specifications and the network maps, and we completed this data with GPS surveys and field observations. The results show that open trenching with a 10 cm sand bed is the most commonly used method, both for PVC pipes (DN63 to DN160) and ductile iron pipes (DN100 to DN1000). We also found that the laying method was adapted depending on the area: concrete encasement in the alluvial soils of Missira and reinforced thrust blocks in the lateritic soils of Sikoro. On the social side, vibrations from heavy machinery affect nearby homes, and some workers refuse to lay pipes in hard rocky soils. The factors that ensure pipe durability are the quality of the sand bed, backfill compaction, joint quality, thrust blocks, pressure testing and disinfection. We therefore recommend carrying out geotechnical studies before any work, training workers, generalizing pressure testing and disinfection, and enriching AMANORMES standards. This study helps improve the sustainability of drinking water infrastructure in Mali, in line with Sustainable Development Goal 6.