The Nigeria Hydrological Services Agency (NiHSA) has warned of a high riverine flood risk across 15 states between September 19 and 25, 2026.

The Director-General and Chief Executive Officer of NiHSA, Arch Umar Mohammed, issued the warning in the agency’s National Flood Advisory, urging affected state governments to take urgent measures to protect vulnerable communities.

According to the advisory, rising river levels are expected to cause flooding in several communities, particularly those located on floodplains.

NiHSA advised residents in vulnerable areas to prepare to relocate to safer and higher ground. It identified monitoring stations including Obubra, Itigidi and Epento along the Cross River as areas where rising river levels could pose significant risks.

The agency said schools, healthcare facilities, markets, farms and religious buildings were among the infrastructure and livelihoods exposed to the anticipated flooding.

In Imo State, the affected Local Government Areas include Aboh-Mbaise, Ahiazu-Mbaise, Ehime Mbano, Ezinihitte, Ideato North, Ihitte/Uboma and Ikeduru. NiHSA identified 958 communities, 1,022 schools, 553 healthcare facilities, 161 markets and 198 religious buildings as exposed.

In Cross River State, the affected areas include Abi, Akamkpa, Akpabuyo, Biase, Calabar, Calabar South, Ikom and Obubra. The agency listed 2,471 communities, 703 schools, 344 healthcare facilities, 145 markets, 453 religious buildings and 854 hectares of farmland as exposed to the risk.

Other states identified in the advisory include Ebonyi, Benue, Anambra and Akwa Ibom, while Edo, Bayelsa, Enugu, Kogi, Delta, Abia, Taraba, Rivers and Lagos were also listed among states expected to experience significant impacts.

In Ebonyi, six Local Government Areas were identified, with 2,574 communities, 1,064 schools, 422 healthcare facilities, 480 markets, 629 religious buildings and 1,882 hectares of farmland exposed.

For Anambra, NiHSA identified seven Local Government Areas, with 1,314 communities, 1,308 schools, 1,089 healthcare facilities, 280 markets, 610 religious buildings and 1,529 hectares of farmland at risk.

The agency called on state governments, emergency management authorities and residents in affected areas to act promptly and implement precautionary measures to minimise the impact of the predicted flooding.