NiHSA warns flooding could persist across Nigeria until September, with peak flooding expected in August. The agency also raises concerns over drinking water contamination.
The Nigeria Hydrological Services Agency (NiHSA) has warned that flooding across parts of Nigeria could persist until September, with conditions expected to worsen in August and September if urgent action is not taken.
Umar Mohammed, director-general of NiHSA, speaking through Emmanuel Tuna, head of the agency’s Geographic Information System (GIS) and Remote Sensing department, told Sunday Vanguard that the agency had issued early warnings before the floods began.
“This is something we foresaw, we saw it coming,” Mohammed said.
“As we speak now, with the flooding happening, if nothing is done, this is just the start of the rainy season, sometime around July-September (12 weeks), and it could be worse than what is even happening right now. And we’re expecting it to be worse around August-September, particularly August-September.”
Drinking water at risk
Beyond the destruction caused by floodwaters, Mohammed said NiHSA is concerned about the impact on drinking water sources. The agency collected baseline data on borehole water quality before the floods and plans post-flood assessments to determine the extent and sources of contamination.
“We were concerned about the drinking water because we expected it to last longer, the flood to last over a long period,” he said.
“So, we started analysing the quality of the water, and we did, we have our reports. We wanted to observe the quality of the water before the flood because we know that after flooding, or even during flood, we are expecting challenges of drinking water in the states.”
Mohammed added that the agency is working to identify specific contamination sources.
“So we can get to confirm what is polluting the water. We want to confirm the sources, particularly the source. So we have before flood records, as we speak, and now that flooding is happening, I am sure my DG is already putting together a team to go to Lagos and get a post-flood report,” he said.
Mohammed said Lagos remains one of the country’s most flood-prone states, exposed simultaneously to urban, riverine and coastal flooding. He cited blocked drainage channels, silt buildup and low-lying terrain as factors worsening the impact of recent rains, with rising river levels compounding the situation.
“We are expecting this flood to be on and off, and to span from July to September on and off,” he said.
“Around October, we are expecting these rains to be receding… the only time we can be safe, I will be honest, is possibly around November.”
States ignoring warnings
Mohammed used the interview to issue a direct rebuke of state governments, accusing them of failing to act on NiHSA’s annual flood outlook and early warnings.
“We have a challenge of cooperation from states, a serious challenge with cooperation from states,” he said.
“Most times we get disregarded. Our warnings are not taken with seriousness.”
Background
Last week, torrential rainfall triggered widespread flooding across parts of Nigeria, with Lagos among the hardest-hit states as roads, homes and critical infrastructure were submerged. The flooding disrupted movement, displaced residents and caused power outages in some communities after floodwaters inundated a transmission substation.
NiHSA’s warning aligns with projections in its 2026 Annual Flood Outlook, which identified Lagos as one of ten priority urban flood hotspots for the year, with urban drainage failure, blocked waterways and coastal surge listed as the primary risk drivers.
