The Ruiru–Juja dam project is a USD 100 million public–private partnership (PPP) structured under a 30-year build–operate–transfer (BOT) arrangement between the Athi Water Works Development Agency and the China Roads and Bridges Corporation (CRBC) as the private partner. The project involves the construction of a 52-meter roller-compacted concrete (RCC) gravity dam with a storage capacity of 18 million cubic meters, complemented by a 50,000 cubic meter per day water treatment plant and 37 kilometers of transmission pipelines to distribute treated water across Kiambu County. The project aims to increase potable water supply to the rapidly urbanizing areas of Ruiru and Juja, while also supporting industrial and commercial development in the Nairobi Metropolitan Region.

The project implementation phase is ongoing, with preparatory works and environmental management plans under review. Once completed, the dam will strengthen water security, enhance climate resilience, and support inclusive economic growth in Kiambu County.