Floods, drainage and climate risk: what to check before buying property in Nairobi

The 2024 long-rains season was the most extreme in living memory for Nairobi. Whole compounds were underwater for days, basements and ground-floor units were destroyed, and a number of property owners discovered that their building sat on riparian reserve or in a poorly engineered drainage path. The 2025 and early 2026 rainy seasons were milder, but the underlying climate risk has not gone away. For diaspora buyers in 2026, flood and drainage diligence is no longer optional. Here is what actually matters when checking a Nairobi property for climate risk.

Riparian land: the single most important check

Kenyan law (Water Act and Survey Act) reserves a minimum 30-metre setback from the highest known water mark of a river or stream. The setback is public riparian reserve. No private title can legitimately exist within it. Buildings inside riparian reserve are at risk of flooding and at risk of demolition orders by the Water Resources Authority (WRA) and county environmental authorities.

In 2024, after the floods, demolitions were carried out across multiple Nairobi suburbs on properties that turned out to sit inside the reserve. Some had legitimate-looking titles. The titles did not protect them from demolition.

What to check. A licensed surveyor’s report mapping the property’s boundaries against the nearest watercourse and confirming clearance of the 30-metre setback. For any plot that is anywhere near a stream, river or seasonal watercourse, do not skip this. The cost of the survey (KES 25,000 to KES 60,000) is small compared with the cost of buying inside a reserve.

Known flood-prone areas

The 2024 floods hit some Nairobi suburbs harder than others. Without naming individual compounds, the suburbs and corridors where flood damage was material in 2024 included:

• Mathare, Mukuru, Kibera and parts of Kawangware: low-income high-density areas with limited drainage infrastructure
• South B and parts of South C around Nairobi River tributaries: pockets of low-lying ground close to watercourses
• Industrial Area: poor surface drainage, multiple incidents
• Athi River and Mlolongo: parts of the Mombasa Road corridor where building has encroached on natural drainage paths
• Pockets of Lavington, Kilimani and Kileleshwa: specific compounds adjacent to the Nairobi River and Kirichwa stream tributaries
• Karen and Hardy: surface flooding on roads and in low-lying compounds, less serious than the high-density areas but still real

This is suburb-level commentary; the relevant unit is always the specific compound. A high-ground compound in any of these suburbs may be entirely fine, and a low-ground compound in an otherwise unaffected suburb may have flooded. Compound-level diligence is the only credible approach.

The seven climate-risk checks worth doing

1. Riparian setback survey. As described above. Critical for any plot near water.
2. Compound elevation versus surrounding ground. Walk the perimeter (or have your inspector do so) and identify the slope. Compounds where the road is higher than the ground floor units are at material risk.
3. Drainage capacity into the public system. Confirm that compound drainage actually connects into a working stormwater system. Many older Nairobi compounds discharge into surface drains that are silted, blocked or undersized.
4. Compound flood history. Ask the management company directly: did this compound experience flooding in 2024 (or 2018 or 2015)? A management company that says “not really” is telling you it did. A management company that says “yes and here is what we did about it” is more reassuring than one that pretends it did not happen.
5. Basement and ground-floor unit history. Specifically check water damage history on the unit you are considering and on units below it. Repeated water damage suggests systemic risk even if the unit you are looking at is dry.
6. Insurance posture. Some Nairobi compounds have had increasing insurance premium loads or loss-of-cover decisions after 2024. Ask whether the management company holds buildings cover and at what premium.
7. Local drainage works status. Both Nairobi City County and individual SRA (Special Rating Area) bodies have invested in drainage upgrades since 2024. Confirm whether works in the immediate area are complete, ongoing or unfunded.

The title and survey reading

A standard title search will not tell you whether the plot sits in a riparian reserve. The cleanest way to confirm is:

1. Obtain the registered survey plan (the deed plan or RIM)
2. Engage a licensed surveyor to physically locate the plot boundaries on the ground and against the nearest watercourse
3. Cross-check against the WRA-mapped riparian reserves where available
4. Confirm that any building on the plot sits outside the 30-metre minimum setback

For sectional title (apartment) purchases, the compound-level riparian work is often already documented as part of the original NEMA approval. Ask for the NEMA EIA report for the development; a credible report addresses watercourses, drainage and setback explicitly.

The longer trend

Whether 2024 was a one-off or a new baseline is a debate without a definitive answer in 2026. What is clear:

• Long rains have become more variable, with higher peak intensity in shorter windows
• Nairobi’s impervious surface area has grown materially in the last decade, increasing surface runoff
• Drainage infrastructure spend has lagged urban development
• Insurance pricing on Nairobi residential property has begun to differentiate between compounds with and without flood history

The reasonable baseline assumption for 2026 buyers is that flood risk is a real, persistent factor worth diligence rather than a tail risk that can be ignored. The good news is that the diligence itself is straightforward and not expensive.

Off-plan in flood-prone corridors

For off-plan purchases, ask specifically about:

• The site survey and elevation drawings
• Stormwater discharge route and county sign-off
• Riparian setback if any watercourse is within 150m of the plot
• Basement design (if any) and flood-mitigation measures
• Insurance coverage during construction and at handover

Developers who can provide all of this confidently are signalling diligence quality. Developers who respond evasively to flood-risk questions are signalling something else.

Climate risk is no longer hypothetical for Nairobi property. The diligence is straightforward, the cost is small, and the consequence of skipping it in a riparian or low-elevation compound can wipe out years of yield in a single season.

How Goldstay handles it

Since 2024, every property we source goes through a documented climate-risk check: riparian setback confirmation, compound elevation against surrounding ground, stormwater discharge route, management-company flood history, and insurance posture. Where any of these come back uncomfortable, we tell the client directly.

Read the related pieces on the importance of physical viewings and the maintenance handbook for the operational picture once you own.