The Nigeria Hydrological Services Agency, NiHSA, says last week’s devastating floods in Lagos were predicted and that conditions could get worse between July and September if urgent action is not taken.
NiHSA Director General Umar Mohammed said the agency’s models had flagged the risk weeks earlier. “This is something we foresaw, we saw it coming,” he stated. He warned that the current flooding “is just the start of the rainy season,” and that August to September could be more severe than what residents are already experiencing
Heavy rainfall began on Sunday, July 5, 2026, and intensified into a torrential downpour lasting more than 12 hours on Tuesday. Roads and properties were submerged, commercial activity stalled, and vehicular movement halted across large parts of the metropolis.
Heavily affected areas included the Lagos-Oshodi Expressway, Abeokuta Expressway by Oshodi Bus Stop, Lekki-Epe Expressway, Victoria Island, Agege, Ikeja, Oworonshoki, Gbagada, Funsho Williams Avenue, Iwaya in Yaba, Lagos Mainland, and several coastal communities. Social media videos showed residents and motorists trapped in floodwater, calling on the state government to intervene
Mohammed explained that Lagos faces three flood types at once: urban, riverine, and coastal/tidal. “Lagos is a coastal state… it also has a very large river that cuts through the city, and it is just by the ocean,” he said.
He added that parts of Lagos are at or below sea level. “Some areas in Lagos are point zero, meaning equal level with the sea. Some places are even below the level of the sea,” he noted, citing GPS readings taken in Ikoyi and other areas. In those low-lying zones, floodwater has nowhere to drain and tends to remain stagnant.
NiHSA’s pre-flood inspections in October-November 2025 found many drains already filled to the brim with stagnant water. “Secondly, these drainages… were not flowing. So there’s a blockage somewhere,” Mohammed said. He also cited siltation from sand, plastics, and debris, which turns drains into “pond systems” instead of channels that carry water out of the city.
The Ogun River compounds the problem. The river splits into tributaries within Lagos before reaching the ocean. With urban drains already full, river water backs into flooded areas, intensifying the impact. “Without this river, it would have just been urban flooding and stagnant. But this flow… intensifies it,” Mohammed said. If high tides coincide with river and urban flooding, he warned, the area submerged could be “way higher.”
Worse Conditions Expected: July to September
The NiHSA boss said the ground is already saturated, so new rain cannot be absorbed quickly. “If it does not escape enough, and more rain comes in, flooding may extend to days, possibly even a week or two,” he warned.
He projected an “on-and-off” flooding pattern from July through September, with peak intensity around August-September. “We are expecting it to be worse around August-September, particularly August-September,” he said. Floods may recede in October, but “the intensity may not be as high” and some risk will remain. He advised that “the only time we can be safe… is possibly around November.”
NiHSA said it will continue issuing weekly forecasts for Lagos and the rest of the country through the end of the year. The agency also noted that some Lagos areas are experiencing flooding for the first time in 2026.
Beyond property damage, NiHSA raised concerns about water quality. “We were concerned about the drinking water across states,” Mohammed said. The agency began analysing borehole and community water sources before the floods to establish a baseline, and is now preparing a post-flood assessment team for Lagos.
The goal is to determine how floodwater is affecting drinking water and to identify pollution sources. Floodwater can carry debris, sewage, and chemicals into boreholes and shallow wells, increasing health risks.
‘Warnings Were Disregarded’
Mohammed said NiHSA raised alarms through the media ahead of the rains, but many state governments did not act. “We have a challenge of cooperation from states, a serious challenge… Most times we come before flood starts… they are not seeing any impending danger. Most times we get disregarded. Our warnings are not taken with seriousness,” he said.
With Lagos sitting at the intersection of urban sprawl, river systems, and the Atlantic, NiHSA says the simultaneous collision of all three flood types is what makes the situation “a challenge.” Without clearing blocked, silted drains and improving drainage flow, the agency warned, the next 12 weeks could bring more disruptive flooding than what Lagos saw last week.
