An environmental impact assessment (EIA) is an assessment of the possible positive or negative impact that a proposed project may have on the environment. This project is an Environmental Impact Assessment report for the proposed expansion of water distribution from Kemtilil water project in Kenya. Saos centre residents and others on downstream suffered over the past years and continues suffering an acute shortage of potable water, commissioning of the proposed project would therefore allow coping with the present shortages. This justified the need for EIA. Consultants carried out environmental study at the proposed site and also the surrounding areas. The environmental study comprised the following activities: mobilization, liaison and consensus building with stakeholders, a scooping exercise, desk and field studies, data analysis, impact assessment, health and safety issues associated with the proposed water project. Evaluation of positive and negative Environmental Impacts was done. Finally, Environmental monitoring and management plan was developed. The proposed Kemtilil Water Project was seen as a major infrastructure project, socially acceptable and recommended for approval.