Nairobi River Systems: Sewarage Reticulation Improvement Project


  • Reference: P-KE-EB0-003
  • Approval date: 06/12/2010
  • Start date: 09/12/2011
  • Appraisal Date: 02/07/2010
  • Status: OngoingOnGo
  • Location: Nairobi, Kenya



2.1.1 The Government's long term development agenda is to improve the health and quality of life and provide cleaner environment through provision of safe and sustainable water and sewerage services. The sector goal is to achieve total coverage of water supply and improved sanitation services throughout the country. The project objective is to improve access, quality, availability, capacity and sustainability of wastewater services in Nairobi through the rehabilitation and extension of sewerage services and wastewater treatment facilities.

2.1.2 The Sewerage Improvement Project is part of the Nairobi Rivers Basin Rehabilitation and Restoration Program. The project has been elaborated in the Nairobi Sewerage Master Plan Study (1998), and further detailed in the feasibility study completed in June 2010. The project focuses on the sewerage infrastructure in Nairobi so that the wastewater being generated in the city is collected and directed to treatment facilities without being an environmental hazard.

2.1.3 The project has three main components, i.e. a) Wastewater Infrastructure - covering rehabilitation and expansion of the Sewerage network and treatment, b) Sanitation, Hygiene and Social Environmental Support, and c) Institutional Development Support. A brief description of the project is given below:

1 Wastewater Infrastructure UA 35,046,000 Extension of trunk sewers (54km) within Nairobi, Ngong, Mathare and Kiu River Basins. This is in areas where sewer lines are non-existent; Laying 40km of reticulation in areas with new trunk lines in medium, low income and informal settlements; Duplication of trunk sewer lines in places where the sewer lines capacity is low or has been encroached; The increased reticulation will connect over 73,000 households and many more to the trunk lines. Immediate connections are important to avoid blockage of new sewer lines. Rehabilitation of Kariobangi conventional wastewater treatment plant operating at 11,000m3/day to full capacity of 32,000m3/day. The plant has facility for gas generation and power from the gas as well as solid waste; Extension of Dandora waste stabilisation ponds by two series of 9 ponds and duplication of inlet works to accommodate increased flow. The works will increase capacity by 40 ,000m3/day. Construction of 100 ablution blocks and collector sewer lines.

2 Sanitation, Hygiene and Social Environmental Support 1,760,000 Hygiene education & community education, Specialised in selected informal settlements. Consultant services to supervise implementation of the ablution blocks, collector sewers and undertake hygiene education. Environmental safeguards, including tree planting, PAP compensations and public consultations

3 Institutional Support and Project Management3,064,000 Training for AWSB & NWSC staff in sewerage systems operation and maintenance management, training, sanitation management study to capture users and wastewater quality discharged into the sewer lines and strengthen sewerage department in NWSC, Study Tours; Provision of office and laboratory equipments; Project management and co-ordination as well as engineering services.


As part of the Nairobi Rivers Basin Rehabilitation and Restoration Prog ramme, the Nairobi Rivers project intends to extend Nairobi sewerage capacity in line with the growing population and the rapid urbanization of the city. The improved sewerage capacity will help to preserve the Nairobi Rivers basins, which are currently heavily polluted by sewer flows.


The Bank proposed support is in line with the Midium Term Strategy 2008-2010 and the Intergrated Water Resources Management Policy of the Bank The Bank's contribution seeks to encourage and support the joint effort of the Government of Kenya and other cooperating partners on the restoration of the Nairobi river on mutual agreement. The results of theimproved sewerage network in Nairobi fianced by the would lead to improved quality of the water in the Nairobi river which can be available for many other uses including domestic and recreation. The Bank group participation in the Nairobi River Program will foster collabolation with other development partners.


The anticipated benefits of the project are the following: at least 1.5 million people including those in informal settlements will benefit from the intervention, protection of the rivers, increase in revenues, overall economic benefits for ASWB and residents, public health benefits, ripple effect on the development of Nairobi, overall environmental protection.

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Finance source Amount
ADFUAC 35,000,000
GovernmentUAC 4,869,580
DeltaUAC 420
TotalUAC 39,870,000