Supply interrupted for testing of flaws in Kenya Pipeline oil installations.
Water Week started on Monday and ends on Friday.
Kenya and Germany are discussing how to improve water and waste water management.
Residents from 10 estates in Nairobi will have no water from Thursday 6am to Friday 6am.
In a public notice on Wednesday, the Nairobi Water and Sewerage Company said supply will be interrupted as the DN600 Outering Road pipeline will be shut down.
This is to facilitate testing for strengths and leaks at oil installations within the Kenya Pipeline Company depot in Industrial Area.
The estates to be affected by the shutdown are Tassia, parts of Fedha, Nyayo Embakasi, Avenue Park 1 and 2, Tumaini flats, Kware Road, Old and New Donholm, Sunrise Estate, Savannah and Greenfields.
The company asked residents to store water and use it sparingly before and during the interruption.