Sand dams offer several economic benefits to communities in arid and semi-arid regions. These structures are cost-effective and require minimal maintenance once built, making them an affordable solution for water scarcity. By storing water in sand-filled reservoirs, sand dams provide a reliable source of water during dry seasons, reducing the need for long-distance travel to collect water. The availability of water supports irrigation, leading to improved crop yields and more stable agricultural production, which enhances food security and generates income for local farmers. Additionally, access to water improves hygiene and health, supporting various economic activities such as brickmaking, and livestock rearing. Many sand dams are built and managed by the communities they serve, fostering a sense of ownership and responsibility, which contributes to their sustainability.
Sand dams help to recharge groundwater which is then extracted for domestic use, farming through irrigation and commercial use in production activities. Sand dams are particularly effective in semi-arid regions and have been successfully implemented in areas like Makueni and Kitui in Kenya.
Construction of a sand dam involving building a reinforced concrete wall across a seasonal river’s sandy riverbed. The wall accumulates sand over a period of time which helps to store water for use during the dry season. The accumulated sand minimizes water loss through evaporation and surface run-off. The sand also acts as a natural filter minimizing the cost of water treatment. Perforated pipes are laid beneath the sand to extract water into an underground reservoir tank. The collected water is then pumped to a storage tank located a few kilometers away from the river for treatment and onward supply to users.
PwC is currently managing the County Green Investment Facility funded by the Financial Sector Deepening Trust Kenya. The facility aims to identify up to five (5) viable green projects in 10 counties of Kenya and support the counties to develop proposals for funding. Green projects are initiatives designed to promote environmental sustainability and reduce negative impacts on the environment. Sand dams are an example of green projects contributing to adaptation and mitigation efforts in several ways. By raising the water table, sand dams support vegetation growth which help in carbon sequestration. Sand dams also offer reliable source of water reducing the need for energy intensive extraction methods ultimately reducing carbon footprint. Sand dams ensure consistent supply of water throughout the year. This enables the communities to engage in production activities such as farming and livestock keeping. They support local ecosystems and biodiversity by maintaining the health of natural habitats, which are vital for climate resilience.
PwC Kenya staff had the pleasure of visiting a sand dam built on Kaiti River during a due diligence exercise on some of the projects proposed by Makueni County for support under the County Green Investment Facility. This specific sand dam can supply approximately 100 cubic meters of water per day to residents of Wote Town. The dam is fitted with a 30MW solar facility powering an immersed pump to supply water to a treatment center for onward consumption. The water is used by town residents, schools, and government facilities. At an estimated cost of KES 30 Million, this dam is a key source of livelihood enabling the community to engage in productive activities such as farming and water vending. Similar dams can be built every one kilometer along the river enabling the county to maximize water storage during the rainy seasons.
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