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Locally built dams on seasonal rivers ease water scarcity, reduce burdens on women and restore ecosystems.
By Kenyan journalist Milliam Murigi. First published in People Daily.
During her childhood in the early 1990’s, Mary Ntuntai, from Enkorika village in Kajiado County, experienced readily available water from the Olkejuado River.
She would walk a few kilometres to fetch water from the nearest source. However, the once-perennial river became seasonal, flowing only during the rainy season. "The situation started changing 20 years ago. I remember when I got married, the river began drying up at times. We were forced to walk farther in search of water. What was once a three kilometers journey soon stretched to six kilometers,” she says.
Initially, the increased walking distance allowed women to socialise and engage in good natured banters.
However, by 2010, rivers dried up shortly after the rains, drastically altering the water availability. Kajiado County's Climate Risk Assessment reveals inconsistent rainfall. Rainfall plummeted from 79.86mm in 2020 to 27.12mm in 2021.
A recovery to 77.89 mm in 2022 was followed by a drastic drop to 5.3mm in 2023, one of the lowest in recent years. 2024 saw a significant increase to 148.06 mm. Community members take part in construction of a sand dam in Kajiado.
Compounding the issue, the mean annual temperature has increased over the past seven years, reaching up to 38.2°C, further drying the region. Consequently, women, traditionally responsible for water collection, face an increased burden, spending hours on what was once a routine task, detracting from farming and family care.
A study in the Journal of Conflict Management and Sustainable Development confirms this challenge across Kajiado County, a semi-arid region plagued by erratic rainfall and prolonged droughts. Deforestation, climate change, population growth, and unregulated sand harvesting exacerbate the water scarcity. Sand harvesting, the extraction of sand from riverbeds for construction, generates income but disrupts river ecosystems.
Excessive sand harvesting degrades riverbeds, reduces water retention, and accelerates river drying. Kajiado County is a major sand supplier to Nairobi and Machakos counties.
A community solution
To address this, communities are constructing sand dams. Jane Nyamwamu, Programme Manager at Neighbours Initiative Alliance (NIA), explains, "A sand dam is a reinforced rubble cement wall built across a seasonal sandy river. These structures slow down the flow of water, enabling sand to accumulate, which in turn helps to retain moisture and replenish underground water reserves.”
Nyamwamu states that sand dams provide a more sustained water supply, reducing the burden on women and enhancing community resilience. NIA has built five sand dams (three on Olkejuado River and two on Isinya Sampin River) providing increased water availability to villages like Enkorika and Maparasha.
Naserian Tiampati from Maparasha village, where a sand dam was built, notes, "Since sand dams were introduced in this area 10 years ago, things have changed. We no longer walk long distances searching for water because potable water is readily available.
Sand dams have transformed our lives by ensuring a steady water supply throughout the year."
Villagers now use hand pumps to access water, and NIA is installing solar pumps. Hand pumps improve access to clean water, hygiene, and sanitation, replacing the unhygienic and laborious practice of digging
scoop holes in dry riverbeds.
To ensure the project's success, Nyamwamu emphasises that once a suitable site for a sand dam is identified—typically along seasonal rivers—local communities, especially women, are involved from the beginning.
Residents contribute labor and locally available materials while NIA covers the costs of technical expertise, construction materials such as cement and steel reinforcements, and training on maintenance and sustainable water management.
This collaboration fosters a sense of ownership and responsibility among the community members.
Additionally, residents take measures to prevent illegal sand harvesting around the sand dams to protect the structures and maintain water retention.
Driven by women
“I was part of the team that built a sand dam at the Olkejuado River. Eighty-five percent of the work was done by women. Women have been at the heart of this initiative because, as the saying goes, ‘The wearer of the shoe knows where it pinches.’ We understand the struggle of walking for miles to fetch water, so we took it upon ourselves to be part of the solution,” Tiampati shares.
“Today, seeing the impact of our efforts—having water close to home, reducing the burden on our women and girls, and improving our livelihoods— makes all the hard work worthwhile.”
However, illegal sand harvesting remains a challenge, as the county lacks proper regulations to control the practice.
According to Nyamwamu, there is a need for stronger policies and community awareness to curb this destructive activity and ensure the long-term benefits of sand dams.
“Without strict enforcement, some individuals continue to extract sand, undermining our efforts to conserve water and restore the environment,” he explains.
Nyamwamu adds that, due to the sand dams, water retention in the rivers has improved, preventing them from drying up too quickly.
Additionally, boreholes near the sand dams now have a more reliable water supply, even during dry seasons. The presence of water has led to increased vegetation growth, restoring the natural environment and reducing soil erosion.
Furthermore, the availability of water has ensured an adequate supply of fodder for livestock, improving the livelihoods of pastoralist communities.
Long-term maintenance and sustainability While sand dams have numerous benefits, experts warn that they are not without drawbacks.
Improperly constructed sand dams can lead to poor water retention or siltation, which reduces their long-term effectiveness.
In some cases, these structures may also alter natural water low, affecting downstream communities and ecosystems that rely on seasonal water availability.
Another concern is the long-term maintenance and sustainability of these structures. Without ongoing technical support and proper community training, many sand dams fall into disrepair. This not only undermines their intended benefits but can also create frustration within the communities they were
designed to help.
To ensure the success and sustainability of NIA’s sand dams, Nyamwamu stresses the importance of proper site selection, conducting environmental impact assessments, and ensuring appropriate spacing
between sand dams to prevent negative impacts on natural water low and surrounding ecosystems. These measures aim to maximize efficiency and sustainability while minimizing potential harm to both communities and the environment.
“This solution has worked and is continuing to work, relieving women of a significant burden that has been on their shoulders for a long time. We urge other counties and countries with dryland environments and sandy rivers to embrace this approach. Sand dams have already been successfully replicated in Kitui, Machakos, and Makueni counties in Kenya. Beyond Africa, similar structures exist in countries like Brazil, Angola, and India,” Nyamwamu says in conclusion.
