In 60 seconds
Floods cost Nigeria an estimated US$6.7 billion in 2022 alone. Dams can reduce flood peaks, but poorly timed releases, such as from Lagdo Dam in September 2022, can make flooding catastrophic.
Forecasts and release notices exist, but warnings often reach downstream communities too late, or without the money, transport and shelter needed to act on them.
The paper sets out seven priority actions, from shared records of reservoir releases to forecast-triggered support for communities at risk.
The full report
By Gbemisola Popoola, Oghoritsewarami Oni and Ibukun Babajide. 23 pages, October 2026.
- A decade of flooding in Nigeria, 2016 to 2025
- How dams reduce floods, and when they make them worse
- Why flood warnings break down at the last mile
- Seven priority actions for safer operations
About this paper
Every rainy season, communities along the Niger and Benue rivers brace for floods. Some of that water falls as rain. Some of it is released from dams upstream, at home and across the border in Cameroon. This paper looks at how dams and reservoir operations shape flood risk in Nigeria, and what would make them safer for the people who live downstream.
Why it matters
Nigeria recorded significant floods every year from 2016 to 2025. The 2022 floods were the worst in a decade. They caused an estimated US$6.7 billion in damage and displaced 2.4 million people. The 2026 Annual Flood Outlook rates 14,118 communities in 33 states and the FCT as highly flood-prone.
How dams can ease floods, or make them worse
Kainji, Jebba and Shiroro, the major hydropower dams on the Niger and Kaduna rivers, can hold back floodwater and lower flood peaks downstream. In 2020, Shiroro released water weeks before the peak rains and reduced the flooding that followed. But timing is everything. Lagdo Dam in Cameroon released water into the Benue on 13 September 2022, in an already wet season, and the release intensified the flooding downstream in Nigeria. In 2024, the failure of Alau Dam sharply worsened flooding in Maiduguri.
Not every flood is a dam flood. Heavy rainfall, blocked drainage and building on floodplains drive much of the loss. In Lagos, wetland area fell by 69% between 1986 and 2020 as developed land grew by 94%.
Where flood warnings break down
NiMet forecasts rainfall, NIHSA tracks river levels and dam operators issue release notices. But warnings often reach downstream communities late, sometimes by radio, and families lack the money, transport or shelter to act on them. Responsibility is split across federal and state bodies. No agency has clear legal power to require a private operator to release water early for flood safety.
Seven priority actions
Shared records of reservoir inflows, storage and releases
Updated wet-season operating rules for each dam
A working notification protocol with Cameroon on Lagdo Dam releases
Dam-specific emergency plans, safety reviews and drills
Forecast-triggered cash and transport support for communities at risk
Land-use rules that keep new building off the most flood-prone land
Careful appraisal of new dams, levees and dredging before money is spent
Download the full report above for the evidence, data and sources behind each action.