Waterworks in Samoa, which is located in the South Pacific, is managed and operated by the Samoa Water Authority (SWA), and about 160,000 people or 85% of the population receive such service. However in Apia, the capital of Samoa, untreated water from the water source was being supplied to 6 out of 10 service areas. Furthermore, they had the problems such as deterioration of water quality due to muddy water in the rainy season, high risk of water-borne diseases, high water leakage ratio, and vulnerability to disasters including cyclone. Therefore, we provided consulting services including basic design, detailed design, construction supervision and technical transfer for the construction of water supply facilities (water treatment plants, intakes, raw water pipelines, water pumping station, water reservoirs, water transmission pipelines, water distribution networks, and water meters) in three areas which were identified as high priority. As a result, we contributed to safe, secure and sustainable water supply to about 11,500 people and the improvement of SWA through the reduction of a non-revenue water (NRW).