# Nairobi Cuts Output at Two Water Plants by 35% as Rationing Warning Spreads

> MKNIRALO — World — KENYA / WATER SUPPLY

- Published: 2026-11-10
- Estimated reading time: 6 minutes
- Byline: Kojo — African Energy & Infrastructure Observer
- Byline disclosure: Kojo is a house editorial byline maintained by MKNIRALO, not a claim of an independently verified individual. It does not imply nuclear engineering credentials, Ghanaian nationality, project employment, site visits or access to nonpublic contracts.
- Author profile: https://mkniralo.com/authors/kojo/
- Tags: Kenya, Nairobi, Water Rationing, Ndakaini Dam, Water Infrastructure, Urban Services
- Cover image: https://mkniralo.com/images/nairobi-water-production-cut-ndakaini-dam-rationing-2026.svg

Nairobi Water cut output at Ngethu and Kigoro by 35% after Ndakaini Dam levels fell, warning seven service providers of longer rationing without a firm end date.

Nairobi's main water utility announced an immediate 35% reduction in output at the Ngethu and Kigoro treatment plants on Monday, November 9, warning that customers could face longer intervals between deliveries. Nairobi City Water and Sewerage Company linked the decision to falling storage at Thika/Ndakaini Dam after below-average rainfall in its catchment. The warning reaches beyond the capital to neighbouring counties served through connected water providers. It is a production restriction intended to conserve reservoir reserves, not a declaration that every Nairobi tap will lose 35% of its usual flow. The company has not named a date when normal output will return.

## The water reduction began immediately

Nairobi Water's November 9 notice says production at Ngethu and Kigoro Water Treatment Plants has been reduced by 35% with immediate effect. It attributes the move to weaker inflows into Thika/Ndakaini Dam, which it describes as the principal source for Nairobi and nearby areas. Less rain in the catchment, the company says, has lowered stored water enough to justify taking less out of the reservoir now. The notice presents the move as a temporary safeguard for continued supply in the months ahead, not as routine planned maintenance.

That distinction matters when interpreting the headline percentage. The company specified a reduction in production at two treatment facilities; it did not publish figures showing that Nairobi's entire water system had lost exactly the same proportion, or that every customer would receive an identical cut. Treatment output, the amount sent into distribution and the water reaching a particular property are different measures. The most immediate conclusion supported by the notice is that less treated water is entering a major part of the metropolitan supply system.

Sources:
- [Nairobi Water public notice: Reduction in Water Supply Due to Reduced Water Levels at Thika/Ndakaini Dam](https://pbs.twimg.com/media/HWqrNoFXEAAOUKw.jpg) — Nairobi City Water and Sewerage Company
- [Longer water rationing periods for Nairobi residents as Ndakaini Dam levels fall](https://beta.nation.co.ke/kenya/counties/nairobi/longer-water-rationing-periods-for-nairobi-residents-as-ndakaini-dam-levels-fall-5664110) — Daily Nation
- [Water rationing in Nairobi and environs over low water levels at Ndakaini](https://www.kbc.co.ke/water-rationing-in-nairobi-and-environs-over-low-water-levels-at-ndakaini/) — KBC Digital

## Seven providers are in the affected network

The notice identifies Nairobi City Water and Sewerage Company, Kiambu Water and Sanitation Company, Githunguri Water and Sanitation Company, Karuri Water and Sanitation Company, Mavoko Water and Sewerage Company, Olkejuado Water and Sewerage Company, and Oloolaiser Water and Sewerage Company. Those are seven service providers, not seven neighbourhoods. The affected service areas extend from Nairobi into parts of Kiambu, Kajiado and Machakos counties, according to Kenyan reporting on the announcement.

Nairobi Water warned of extended rationing periods for customers served by these companies. In practical terms, a household already receiving water on allocated supply days may have to wait longer, but the notice contains no replacement timetable by neighbourhood. It also does not say that every connection across all seven providers will be interrupted simultaneously. The specific experience will depend on each provider's distribution arrangements, local storage and scheduled supply hours; customers will need provider-level updates before they can plan around an exact day or time.

Sources:
- [Nairobi Water public notice: Reduction in Water Supply Due to Reduced Water Levels at Thika/Ndakaini Dam](https://pbs.twimg.com/media/HWqrNoFXEAAOUKw.jpg) — Nairobi City Water and Sewerage Company
- [Longer water rationing periods for Nairobi residents as Ndakaini Dam levels fall](https://beta.nation.co.ke/kenya/counties/nairobi/longer-water-rationing-periods-for-nairobi-residents-as-ndakaini-dam-levels-fall-5664110) — Daily Nation
- [Water rationing in Nairobi and environs over low water levels at Ndakaini](https://www.kbc.co.ke/water-rationing-in-nairobi-and-environs-over-low-water-levels-at-ndakaini/) — KBC Digital
- [Nairobi Faces Water Shortage, Extended Rationing as Thika, Ndakaini Dam Levels Drop, Supply Cut by 35%](https://www.pulse.co.ke/story/nairobi-faces-water-shortage-extended-rationing-as-thika-ndakaini-dam-levels-drop-supply-cut-by-35percent-2026110910365589550) — Pulse Kenya

## Why the Ndakaini reservoir matters

The utility's own description of Thika Dam, also called Ndakaini, lists a designed storage capacity of 70 million cubic metres. Its published dam fact sheet says the system contributes approximately 84% of Nairobi's water supply. Those figures explain why a reduction in reservoir inflows can affect a wide area, but they are background descriptions of infrastructure and dependence, not measurements of the dam's current contents on November 9. The notice does not state what proportion of the reservoir remains full.

The reservoir collects water from a catchment that includes the Thika, Githika and Kayuyu rivers, and its associated system serves Ngethu Water Treatment Works, according to Nairobi Water. Storage smooths out the gap between rain arriving and water being used. When inflows weaken, maintaining the previous rate of abstraction can draw down reserves faster. By slowing extraction, the utility is attempting to keep some supply available for a longer period. The notice does not establish how much water that decision will save, nor whether rainfall will recover soon enough to shorten rationing.

Sources:
- [Nairobi Water public notice: Reduction in Water Supply Due to Reduced Water Levels at Thika/Ndakaini Dam](https://pbs.twimg.com/media/HWqrNoFXEAAOUKw.jpg) — Nairobi City Water and Sewerage Company
- [THIKA DAM](https://nairobiwater.co.ke/thika-dam/) — Nairobi City Water and Sewerage Company
- [Water rationing in Nairobi and environs over low water levels at Ndakaini](https://www.kbc.co.ke/water-rationing-in-nairobi-and-environs-over-low-water-levels-at-ndakaini/) — KBC Digital

## A separate 24-hour shutdown should not be confused with rationing

Residents were also warned of a scheduled interruption from 8 a.m. on Monday, November 9, to 8 a.m. on Tuesday, November 10. That notice concerned installation of new pipe connections near Kianda School off Waiyaki Way. It identified specific Nairobi areas, including Westlands, Riverside and Parklands, as well as other estates and institutions. The work was planned in advance to connect infrastructure; it was not the cause given for the broader production reduction at Ngethu and Kigoro.

Both announcements can affect the same household, which makes the difference easy to miss. The local shutdown has a stated maintenance window and named service areas, while the reservoir-related cut has an immediate starting point but no scheduled end. Finishing pipe work does not, by itself, restore the water removed from production because of low dam storage. Conversely, the 35% production notice should not be used to suggest that every location listed for the pipe connection works is under a continuous, indefinite shutdown.

Sources:
- [Nairobi Water public notice: Reduction in Water Supply Due to Reduced Water Levels at Thika/Ndakaini Dam](https://pbs.twimg.com/media/HWqrNoFXEAAOUKw.jpg) — Nairobi City Water and Sewerage Company
- [Westlands, Kilimani and other estates in Nairobi to experience 24-hour water supply interruption](https://k24.digital/news/westlands-kilimani-and-other-estates-in-nairobi-to-experience-24-hour-water-supply-interruption) — K24 Digital
- [Water rationing in Nairobi and environs over low water levels at Ndakaini](https://www.kbc.co.ke/water-rationing-in-nairobi-and-environs-over-low-water-levels-at-ndakaini/) — KBC Digital

## The utility has not set a restoration date

The company said it was monitoring water levels and weather conditions and would review output periodically. It did not announce a threshold at which it would reverse the cut, an updated daily production total or a date for ending longer rationing. The warning therefore describes a condition that may change as reservoir inflows change, rather than a fixed timetable that households can put on a calendar. Reporting on the notice likewise found no new citywide rationing schedule.

There is an important limit to what can be inferred from that silence. A missing restoration date does not mean the restriction will remain forever, but neither does the word temporary guarantee normal service within days. Rain falling elsewhere in Kenya would not automatically replenish this particular catchment. Meaningful updates would include actual dam storage, catchment rainfall and river inflows, revised treatment-plant output and any new distribution notices from the affected providers. Without those details, forecasts about the length of the shortage would be speculation.

Sources:
- [Nairobi Water public notice: Reduction in Water Supply Due to Reduced Water Levels at Thika/Ndakaini Dam](https://pbs.twimg.com/media/HWqrNoFXEAAOUKw.jpg) — Nairobi City Water and Sewerage Company
- [Longer water rationing periods for Nairobi residents as Ndakaini Dam levels fall](https://beta.nation.co.ke/kenya/counties/nairobi/longer-water-rationing-periods-for-nairobi-residents-as-ndakaini-dam-levels-fall-5664110) — Daily Nation
- [Nairobi Faces Water Shortage, Extended Rationing as Thika, Ndakaini Dam Levels Drop, Supply Cut by 35%](https://www.pulse.co.ke/story/nairobi-faces-water-shortage-extended-rationing-as-thika-ndakaini-dam-levels-drop-supply-cut-by-35percent-2026110910365589550) — Pulse Kenya

## What customers should watch next

For households, the utility's immediate request is to use available water carefully and avoid waste, while putting essential needs first. That is particularly relevant to homes, shops and institutions whose service already arrives intermittently. Customers should check the notices of their own supplier rather than assume that a schedule circulating for one Nairobi district applies in Kiambu, Kajiado or Machakos. If a notice specifies planned pipe maintenance, its dates and affected streets need to be read separately from the open-ended reservoir warning.

The decisive next announcement will be a verified change in production or a new rationing timetable, not simply an expectation of rain. Nairobi Water says it will review the operating decision as conditions evolve. For now, the confirmed news is narrower and more consequential than a general drought headline: reduced output at two treatment works, a warning spanning seven water companies and no fixed return-to-normal date. Residents can prepare for less predictable supply without assuming that all of Nairobi has been shut off or that the scheduled Tuesday maintenance endpoint resolves the wider problem.

Sources:
- [Nairobi Water public notice: Reduction in Water Supply Due to Reduced Water Levels at Thika/Ndakaini Dam](https://pbs.twimg.com/media/HWqrNoFXEAAOUKw.jpg) — Nairobi City Water and Sewerage Company
- [Water rationing in Nairobi and environs over low water levels at Ndakaini](https://www.kbc.co.ke/water-rationing-in-nairobi-and-environs-over-low-water-levels-at-ndakaini/) — KBC Digital
- [Westlands, Kilimani and other estates in Nairobi to experience 24-hour water supply interruption](https://k24.digital/news/westlands-kilimani-and-other-estates-in-nairobi-to-experience-24-hour-water-supply-interruption) — K24 Digital
- [Nairobi Faces Water Shortage, Extended Rationing as Thika, Ndakaini Dam Levels Drop, Supply Cut by 35%](https://www.pulse.co.ke/story/nairobi-faces-water-shortage-extended-rationing-as-thika-ndakaini-dam-levels-drop-supply-cut-by-35percent-2026110910365589550) — Pulse Kenya

## About this article

This article reflects the public sources available on the publication and update dates shown above. For developing stories, follow the linked source pages for subsequent statements or decisions.

## Sources and further reading

- [Nairobi Water public notice: Reduction in Water Supply Due to Reduced Water Levels at Thika/Ndakaini Dam](https://pbs.twimg.com/media/HWqrNoFXEAAOUKw.jpg) — Nairobi City Water and Sewerage Company (published 2026-11-09) (accessed 2026-11-09)
- [THIKA DAM](https://nairobiwater.co.ke/thika-dam/) — Nairobi City Water and Sewerage Company (accessed 2026-11-09)
- [Longer water rationing periods for Nairobi residents as Ndakaini Dam levels fall](https://beta.nation.co.ke/kenya/counties/nairobi/longer-water-rationing-periods-for-nairobi-residents-as-ndakaini-dam-levels-fall-5664110) — Daily Nation (published 2026-11-09) (accessed 2026-11-09)
- [Water rationing in Nairobi and environs over low water levels at Ndakaini](https://www.kbc.co.ke/water-rationing-in-nairobi-and-environs-over-low-water-levels-at-ndakaini/) — KBC Digital (published 2026-11-09) (accessed 2026-11-09)
- [Westlands, Kilimani and other estates in Nairobi to experience 24-hour water supply interruption](https://k24.digital/news/westlands-kilimani-and-other-estates-in-nairobi-to-experience-24-hour-water-supply-interruption) — K24 Digital (published 2026-11-08) (accessed 2026-11-09)
- [Nairobi Faces Water Shortage, Extended Rationing as Thika, Ndakaini Dam Levels Drop, Supply Cut by 35%](https://www.pulse.co.ke/story/nairobi-faces-water-shortage-extended-rationing-as-thika-ndakaini-dam-levels-drop-supply-cut-by-35percent-2026110910365589550) — Pulse Kenya (published 2026-11-09) (accessed 2026-11-09)