Flooding and Health in Nigeria: What Happens After the Water Rises, and How to Protect Your Family

Last reviewed: October 16, 2026 | By Ugochukwu Dike

Floods are usually reported as a story about water: how high it rose, which roads closed and how many homes were damaged. For health, the story continues long after the water goes down. Contaminated water, damaged homes, broken power supply and the stress of losing belongings can affect a family for weeks or months.

Why this matters in Nigeria right now

The Nigeria Hydrological Services Agency (NIHSA) issued its 2026 Annual Flood Outlook on April 15, 2026. According to the agency’s official flood-risk atlas, 26,224 communities, with an estimated population of 18,813,378, are identified as being at risk over the full year. For October and November 2026, the outlook identifies 20,755 communities and an estimated population of 13,831,681 at risk across 37 states [1]. These are forecast estimates, not confirmation that every listed community or resident will experience flooding. People living in flood-prone areas should follow local warnings and prepare for possible flooding.

If you live near a river, the coast or a poorly drained street, now is the time to prepare.

How floods harm health

Immediate dangers. Hazard references that cite the World Health Organization (WHO) say about two-thirds of flood-related deaths are from drowning. The rest come from physical trauma, heart attacks, electrocution, carbon monoxide poisoning and fire [3]. Carbon monoxide is a risk because many people run generators in or near their homes during power cuts. We cover generator safety in a separate article.

Delayed dangers. Floodwater mixes with sewage, refuse and chemicals. Power cuts can also stop water treatment plants working, which raises the risk of water-borne disease [3]. Diseases that can spread more easily after floods include typhoid, cholera, leptospirosis and hepatitis A, as well as mosquito-borne illnesses such as malaria [3].

Cholera deserves special attention. WHO links outbreaks to limited access to safe water and sanitation, which can result from climate events such as cyclones, floods or drought [4]. Nigeria’s cholera season has been serious. The Nigeria Centre for Disease Control and Prevention (NCDC) reported more than 65,000 suspected cholera cases across 35 states and about 195 local government areas in 2026 [5][6]. Its Director-General has said cholera transmission can peak between late August and October [6].

The mental health toll

Mental health is part of flood recovery too. WHO notes that almost everyone affected by an emergency feels psychological distress, and for most people this eases over time. A minority go on to develop conditions such as depression or post-traumatic stress disorder (PTSD) [7].

Consider talking to a doctor or mental health professional if, weeks after the flood, you or a family member:

• cannot sleep or has frequent nightmares,
• feels constantly on edge or has panic attacks,
• withdraws from family and friends, or
• uses alcohol or other substances to cope.

Routine, rest, regular meals and talking with people you trust all help. Children often show distress through changes in behaviour, so watch for those too.

Before a flood: prepare

• Know your risk. Check whether your area appears in NIHSA’s flood outlook and follow local flood alerts. Identify the route to higher ground and agree a meeting point with your family.
• Pack a go-bag. Include oral rehydration salts (ORS), drinking water and water treatment tablets, a torch, a power bank, a first-aid kit, regular medicines, spare clothes, some cash, and copies of important documents in a waterproof bag.
• Raise what you can. Move documents, electronics and chemicals to higher shelves.
• Keep drains clear. Do not dump refuse in gutters, and report blocked drains to your local authority.
• Plan for power cuts. Never run a generator indoors or in an enclosed space.
• Look out for neighbours who are elderly, ill or living alone.

During a flood

• Do not walk, swim or drive through floodwater. It can hide open drains, debris and live electrical wires.
• Stay away from fallen power lines, and switch off electricity at the mains if it is safe to do so.
• Do not drink floodwater. Do not drink tap or borehole water until it has been boiled or treated.
• Keep children away from floodwater.

After a flood: protect your health

1. Make water safe first. Treat all drinking water as unsafe until it has been boiled or properly treated.
2. Wash your hands with soap and safe water, especially before eating and after cleaning.
3. Throw away food that touched floodwater, and wash plates and cups with safe water.
4. Clean and dry your home. Wear boots and gloves, scrub surfaces with detergent and open windows to dry rooms.
5. Fight mosquitoes. Empty standing water around the house and sleep under a net.
6. Get care when you are ill. Seek medical help for fever, infected wounds, or diarrhoea and vomiting.

Cholera warning signs. Severe watery diarrhoea can cause dangerous dehydration within hours [4]. Go to a health facility straight away and sip ORS on the way. WHO says most people with cholera can be treated successfully with ORS, while severe cases need intravenous fluids and antibiotics [4].

What communities can do

Nigeria’s Minister of Water Resources and Sanitation has linked rising flood incidents to climate variability, rapid urbanisation, inadequate drainage and poor land-use practices [8]. Households cannot fix all of that alone, but communities can keep drains clear, avoid building on waterways, and press local authorities for better drainage.

Conclusion

Flood season brings risks beyond the water itself. Preparing early, staying out of floodwater, making water safe, and watching for illness and stress can protect your family long after the rain stops.

This article gives general health information and is not a substitute for medical advice. If you or someone you care for is ill, see a qualified health worker.

About the author: Ugochukwu Dike holds a B.Sc. (Hons) in Anatomy from the University of Calabar and is studying B.Sc. Environmental Health Science at the National Open University of Nigeria.

References

1. allAfrica. “Nigeria: 14,000 Communities At ‘High Risk’ As Severe Flooding to Hit Abia, Anambra, 32 Others.” 15 April 2026. https://allafrica.com/stories/202604160046.html
2. IFRC. Nigeria Flood Operation (DREF), 2026. https://go-api.ifrc.org/api/DownloadFile/95410/MDRNG045do
3. UNDRR PreventionWeb. Hazard definition on flooding and health effects, citing WHO. https://www.preventionweb.net/understanding-disaster-risk/terminology/hips/mh0606
4. World Health Organization. Cholera fact sheet. https://www.who.int/news-room/fact-sheets/detail/cholera
5. News Agency of Nigeria. “NCDC: Nigeria records 65,000 suspected cholera cases.” 28 August 2026. https://nannews.ng/tag/65000/
6. Leadership. “Cholera Cases Hit 65,000, Diphtheria Exceeds 10,000 In 2026 – NCDC.” https://leadership.ng/?p=686197
7. World Health Organization. Mental health in emergencies. https://www.who.int/news-room/fact-sheets/detail/mental-health-in-emergencies
8. News Agency of Nigeria. “Flood expected in 33 states, FCT  Minister.” https://nannews.ng/flood-expected-in-33-states-fct-minister/