Nairobi City Water and Sewerage Company has told customers in large parts of the capital to brace for a 26-hour water supply interruption beginning on 11 September 2026, after the utility scheduled an emergency shutdown of the Sasumuma Water Treatment Plant to carry out repairs on the Sasumuma–Kabete pipeline, according to a report published on 11 September by K24 Digital.
Key takeaways
- Shutdown window runs from 6:00 a.m. on Friday 11 September 2026 to 8:00 a.m. on Saturday 12 September 2026, a 26-hour outage, as reported by K24 Digital.
- The trigger is emergency repair work on the Sasumuma–Kabete pipeline, forcing the Sasumuma Water Treatment Plant offline, according to K24 Digital.
- Affected zones span Westlands, Kileleshwa, Upper Hill, Karen, Langata, the CBD and JKIA airport corridor, plus Eastlands and the Mathare/Huruma corridor, as listed by K24 Digital.
- Major institutions in the cut list include Kenyatta National Hospital, the University of Nairobi main campus, Daystar University, Coptic Hospital, Mathari Hospital, Jomo Kenyatta International Airport and the SGR terminal, as reported by K24 Digital.
- Customers were told to store adequate water in advance and use available supplies sparingly, per the utility's public notice carried by K24 Digital.
What happened
In a public notice issued on Thursday 10 September 2026, Nairobi City Water and Sewerage Company said the Sasumuma Water Treatment Plant would be taken offline so crews could carry out emergency repair works along the Sasumuma–Kabete pipeline, the utility said, as reported by K24 Digital. The plant is being shut from 6:00 a.m. on Friday 11 September 2026 and is scheduled to return to service at 8:00 a.m. on Saturday 12 September 2026, a continuous 26-hour outage, according to K24 Digital.
The utility warned that supply would be interrupted in several parts of Nairobi City County during the repair window and asked customers to "store adequate water in advance and use available supplies sparingly," as quoted by K24 Digital. The cut list published by the company is unusually broad, covering high- and low-income neighbourhoods on both sides of the city and a string of major users: the Kenyatta National Hospital complex, the University of Nairobi main campus, Daystar University, Coptic Hospital, Mathari Hospital, the Jomo Kenyatta International Airport (JKIA) and the Standard Gauge Railway (SGR) terminal, as listed by K24 Digital.
For plant managers and procurement leads, the operational shape of the event is a single-source, single-pipeline emergency. A transmission main serving a single treatment plant has been isolated for 26 hours, so anything downstream — reservoirs, booster stations, industrial offtakes, hospital feeds and airport supplies — has lost raw-water input for the duration, as reported by K24 Digital. The company has not disclosed the nature of the emergency repair, the diameter of the pipeline, or the volume of supply affected in the notice carried by K24 Digital.
Specification read
The source does not publish a treated-water volume in MLD or m³/day for the Sasumuma Water Treatment Plant, so the scale of the outage can only be read in qualitative terms: a 26-hour shutdown of one plant feeding large parts of a city of several million residents, as reported by K24 Digital. For a conventional surface-water treatment train of this class — screening, coagulation-flocculation, sedimentation, filtration and chlorine disinfection feeding a long-distance transmission main — the bottleneck being addressed is the pipeline between the plant and the city, not the treatment process stages themselves, as described in K24 Digital. For municipal utilities and large campus users (hospitals, universities, airport operators) on a single-source supply, the engineering read is that storage volume, standby pumping and on-site treatment redundancy become the deciding factors during a 26-hour raw-water loss (general industry range, not from the sources). Buyers scoping similar projects should look at Municipal treatment packages and the wider Industries We Serve portfolio, and compare biological-stage choices in adjacent guides such as MBR vs Conventional Activated Sludge for Mining Wastewater: 2026 Ellwood City Guide and MBR vs Conventional Activated Sludge for Mining Wastewater 2026: Footprint Guide when sizing biological capacity for redundancy.
If your facility is a large municipal or institutional user on a single-source raw-water main with limited on-site storage (flow in the tens of thousands of m³/day range, BOD/COD in the typical municipal drinking-water source envelope, public-health compliance pressure), this event is a reminder that a 26-hour raw-water interruption translates directly into a 26-hour treated-water shortfall at the tap unless storage, borehole backup or tanker contracts are in place, and that pipeline-stage failures upstream of the plant are the trigger you plan around (general industry range, not from the sources).
FAQ
How long will the Nairobi water supply be off?
The utility has scheduled the shutdown from 6:00 a.m. on Friday 11 September 2026 to 8:00 a.m. on Saturday 12 September 2026, a continuous 26-hour outage, as reported by K24 Digital.
Which parts of Nairobi are affected?
Westlands/Lavington, Kileleshwa, the University of Nairobi/Valley Road area, Kilimani/Hurlingham, Upper Hill, Dagoretti/Kawangware/Waithaka, Uthiru/Mutuini/Gatina, the Jamhuri/Kabarnet/Kenyatta Market vicinity, Kibera, Kang'ethe/Togo Flats, Langata/Nairobi West/Madaraka, Karen, the CBD/South B and C/JKIA corridor, Ngara/Gigiri/diplomatic areas, Eastlands and the Mathare/Huruma/Outer Ring corridor, as listed by K24 Digital.
What is causing the outage?
Emergency repair works along the Sasumuma–Kabete pipeline, which is forcing the Sasumuma Water Treatment Plant offline, as reported by K24 Digital. The company has not published the repair scope or pipe diameter in the notice carried by the outlet.
What should large users such as hospitals or the airport do during the window?
Pre-fill storage, ration non-essential use, and arrange tanker or borehole backup for the 26-hour window, as advised by Nairobi Water and reported by K24 Digital. Sizing of standby storage is a site-specific decision; typical design buffers for critical-care and aviation users run from 24 to 72 hours of average demand (general industry range, not from the sources).
