On 10 September 2024, the collapse of Alau Dam caused a catastrophic flash flood in Borno State, Nigeria, severely affecting Maiduguri Municipal Council (MMC) and Jere Local Government Area (LGA). The flood resulted in loss of life, injuries, and mass displacement, and raised concerns about waterborne disease from contaminated water sources. This study assessed the microbial quality of water samples collected from five flood-affected locations: Monday Market, Post Office, College of Nursing, Shehuri, and Buduri. Samples were analysed using standard microbiological methods to determine total bacterial count (TBC) and to isolate and identify selected bacterial contaminants. TBC was elevated at all sampling sites, with the highest count recorded at Monday Market (9.3 × 10⁶ CFU/mL). Escherichia coli, Shigella spp., Salmonella spp., Vibrio cholerae, and Klebsiella spp. were detected, and contamination levels varied among the five locations. The presence of these organisms, particularly the faecal indicator E. coli, suggests faecal contamination of the floodwater. These findings indicate a significant risk of waterborne diseases such as cholera, shigellosis, and salmonellosis in the affected communities. They highlight the need for systematic water-quality monitoring, confirmatory identification of priority pathogens, access to safe drinking water, improved sanitation and hygiene, and coordinated public health interventions following flooding. Read more