With relentless drought-induced land degradation threatening to turn large parts of Lesotho into deserts, some rural communities are building sand dams in a bid to arrest ongoing erosion.
Desertification is the process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture while soil erosion is defined as the wearing away of topsoil. The building of sand dams is however, one part of the puzzle.
Lesotho is among the countries most threatened by erosion-induced land degradation and desertification and, according to reports, the current rate of soil loss suggests the country will be a desert in less than 15 years.
To cushion the potentially catastrophic effects of desertification, the community of Bethel in Mohale’s Hoek is building sand dams aimed at combatting the challenges of water scarcity and environmental degradation.
The southern districts of Mohale’s Hoek and Mafeteng are the most affected by the effects of climate change in Lesotho.
A sand dam is a reinforced cement wall built across a seasonal (flows after major rainfall, then dries up again) sandy river. The dams are built by securing one or two long concrete barriers across river beds, and by placing a pipe under these barriers.
According to the founder and managing director of the Bethel Business and Community Development Centre (BBCDC) Ivan Yaholnitsky, they have so far built nine sand dams in the Bethel area in addition to two others in Thaba Tseka Ha Mafa.
“Sand dams offer a sustainable source of water, which can be used for irrigation and potable water supply. We help ensure a consistent water supply, thereby contributing to community resilience and agricultural productivity.
“It is the mission of BBCDC to teach young men and women general engineering skills, manual capabilities, applied sciences and leadership abilities that address the needs of rural and urban development in Lesotho, and to pursue financial self-sustainability through self-reliance, commercial endeavour, and responsible environmental management.
“BBCDC addresses several thorny and interdependent development problems, including: educational innovation, landscape regeneration and water resources improvement, financial independence, adoption of renewable energy platforms, appropriate technology, and design of the built environment for sustainability. The school’s primary mission is to provide skills and knowledge to young men and women for well-being and self-reliance through experiential learning,” Yaholnitsky says.
He explains that these structures are designed to capture and retain water in streams, especially in areas experiencing desertification and land degradation, like the districts of Maseru and Quthing.
The landscape in Mohale’s Hoek is characterised by straightened rivers that often run over a bedrock, which leads to increased stream velocity and erosion.
In contrast, Yaholnitsky says, healthy watersheds have meandering rivers filled with sediment, where vegetation plays a crucial role in slowing water flow and stabilizing the ecosystem.
The implementation of sand dams can help restore these watersheds, capturing rainwater and improving water availability, while also enhancing soil health and reducing erosion.
“By addressing the challenges of watershed degradation, sand dams represent a sustainable solution for communities struggling with water scarcity and environmental decline.
“There isn’t widespread awareness of sand dams, despite their low cost and the simplicity of the materials needed – sand, rock, and cement. Bureaucratic obstacles contribute to this lack of awareness. Many decision-makers remain disconnected from the realities on the ground, often confined to their offices rather than engaging with communities directly.”
“Without water, solar radiation is converted into sensible heat, raising temperatures on dry surfaces. In the absence of moisture, this heat accumulates instead of being dissipated. Water has a significant energy capacity; as it transitions from liquid to vapour, it absorbs 2.4 megajoules per litre. When it condenses, it releases this heat, influencing local temperatures and humidity,” he says.
Yaholnitsky adds that the lack of water leads to a re-dehumidification of the landscape, which disrupts the thermodynamic balance of the environment.
This process can have severe implications for ecosystems, agriculture, and overall climate stability, highlighting the critical need for sustainable water management solutions, such as sand dams, to restore moisture and promote ecological health.
According to the land degradation neutrality target setting in Lesotho summary report of 2019, over the last 20 years, the country is reported to have lost over 100 000 hectares of arable land, resulting in a 25 percent decrease in usable land for the production of food and fodder.
The report states that the loss of biological diversity, the deterioration of rangelands and poor agricultural and livestock productivity are visible signs of land degradation and the advancement of desertification in Lesotho.
“Rangeland carrying capacity and quality have declined, which has also affected special and fragile ecosystems in the country’s alpine regions.
“Moreover, climate change continues to make agricultural and livestock production increasingly difficult and uncertain. Land and soil degradation continue to reduce the land’s capacity to store water, with a great impact on the rain-fed agricultural production system that dominates in Lesotho.
“The country’s major highlands watersheds, which are the main sources of water for communities and are the main river tributaries, experience recurrent episodes of drought, leading to the loss the unique plant communities and habitats supporting a variety of endemic species,” the reports reads.
The report further states that recognising the adverse effects that desertification, land degradation and drought has had on the health and wellbeing of communities and ecosystems, Lesotho has been taking measures to combat DLDD, including the ratification of the United Nations Convention to Combat Desertification (UNCCD) in 1995.
“As a further measure to combat DLDD and protect biodiversity and ecosystems, Lesotho joined the Land Degradation Neutrality (LDN) Target Setting Programme (TSP) and committed to achieving LDN by 2030, recognising the importance of land as a vital resource for human health and wellbeing,” it points out.
According to a 2010 report by the Global Mechanism to United Nations Convention to Combat Desertification through a programme Land Degradation Neutrality (LDN) on Lesotho, annual cost of land degradation in Lesotho is estimated at M827 million.
Huge dongas are a testimony to the negative effects of soil erosion as the bedrocks seen in most areas are also a testimony to lost soil.
Inhabitants are continuously neglecting land protection initiatives, resulting in the loss of soil surface.
The report by the Global Mechanism to United Nations Convention to Combat Desertification says in Lesotho, 46 000 people were living on degrading agricultural land in 2010,- a decrease of eight percent in a decade, bringing the share of rural residents who inhabit degraded agricultural land up to three percent of the total rural population.
The report explains that land degradation can severely influence population’s livelihood by restricting people from vital ecosystem services- including food and water- increasing the risk of poverty.
“During the same period (2000-2010), the amount of people residing in remote degrading agricultural areas with limited market access declined by 11 percent, reaching 33 000 people.
“Populations in remote areas have restricted options for managing land and accessing other benefits of economic development,” the report reads.
According to United Nations Convention to Combat Desertification, Sustainable Development Goal 15: Life on Land calls for the protection, restoration and sustainable management of land-based ecosystems. In doing so target 15.3 specifically aims to achieve a land degradation-neutral world by the year 2030.
The United Nations Convention to Combat Desertification revealed that 3.2 billion people worldwide are negatively impacted by desertification
10 percent of gross domestic product is lost due to desertification per year.
