- NCWSC shut down water production from Ng’ethu on May 1 due to heavy rainfall in the Aberdares causing high turbidity.
- Muguna said heavy rains within Aberdares had subsided, meaning there was less turbidity.
Water availability in the city will improve beginning Friday, the distributor has said.
Nairobi City Water and Sewerage Company acting MD Nahason Muguna told the Star there was increased production at Ng’ethu water treatment plant as turbidity had gone down.
“We are now producing 18,500 cubic meters per hour,” Muguna said, adding that they used to produce 17,500 per day due to high turbidity.
Ng’ethu serves 85 per cent of Nairobi with water. NCWSC shut down water production from Ng’ethu on May 1 due to heavy rainfall (79mm) in the Aberdare Ranges, their main catchment area.
The heavy rains had increased river flow, causing very high turbidity in the raw water suspected to be caused by a landslide upstream.
Turbidity is the quality of being cloudy, opaque, or thick with suspended matter. Its measurement is a key test of water quality.
NCWSC production manager Philip Githinji had told the Star the situation was “fluid.”
Githinji said they were dealing with very high turbidity of above 5,000 NTU (Nephelometric Turbidity Units) causing them to temporarily shut the systems then resume once turbidity went down.
The normal raw water quality for 85 per cent turbidity is below 100 NTUs.
WHO requires portable water to be below five NTUs after treatment.
Githinji said a conventional water treatment system like Ng’ethu treats up to 800 NTUs.
On May 3, NCWSC resumed production and transmission to the city. Most of the water was directed to the densely populated areas of Mathare, Mukuru, Korogocho and Kibera.
This was after turbidity levels decreased to an acceptable level to enable treatment of the water.
On Friday, Muguna said heavy rains within Aberdares had subsided, meaning there was less turbidity.
On May 8, the company also shut down water production at Sasumua Dam, which supplies 11.6 per cent of water to Nairobi.
The move was occasioned by a massive a landslide in Karemenu River inside the Aberdare Ranges forest.
The area experienced heavy rains making access very difficult.
Muguna said on Friday the roads into the forest had been repaired to enable engineers to access the site.
“Engineers are on the ground doing a pipe to the new alignment. The line will be laid for 4km in a better terrain to reduce chances of pipes being washed away,” Muguna said.
He said the work would take between 14 to 21 days.
Edited by Henry Makori