Loss of rainfall attributed to climate change
has stimulated new innovations of accessing water in dry seasons. Development
experts are assisting smallholder farmers and rural communities' in accessing
clean water while responding to global warming.
Scientific studies have shown that the
ever-increasing global temperature is reducing the size of water basins in many
developing countries like Zambia. Some areas that were traditionally wetlands
are now facing constant drought. Other areas that were initially drought prone are now experiencing severe flooding. The fluctuations in weather
conditions has led to poor water supply and increased water-borne diseases such
In an effort to assist Zambia's rural
communities in their ability to respond and adapt to global warming, a team of
experts is encouraging smallholder farmers and rural communities to set up rain
water harvesting structures. The team is
also assisting in the effort. The Zambia National Farmers Union through its
Conservation Farming Unit is helping farmers dig water harvesting basins. Water
Harvesting is a simple and cheap technique for collecting excess water for
drinking or irrigation. The water is usually retained in either small dams, manually-dug
basins or huge underground storage tanks.
Lisa Sendwe is the Agro-forestry Farm Manager
at the Conservation Farming Unit of the Zambia National Farmers Union in
Chisamba, Central Zambia.
Sendwe notes that in semi-arid and arid
areas, a year's rainfall may occur in just a few big storms. With insufficient
water storage facilities most of the water is simply lost.
She explains that in this case, rain water
harvesting is certainly advisable for rural communities to adapt to global
warming and erratic water supply.
"You know our rainfall pattern is bad. So
what happens usually is we talk to farmers how to dig a basin. This basin will
be like a reservoir. It will capture the water and hold the water such that
even if there will be a drought for sometime…that water will be utilized by
the plants because it will be kept in the basin for sometime and we dig
permanent basins," she says.
Recent studies have shown that African
farmers on rain-fed land will lose $28 per hectare per year for each Celsius
degree rise in global temperature. Global warming erodes coastlines, undermines
access to water, spreads pests and water-borne disease and produces more
erratic weather patterns.
Noting the serious effects of global warming
on water access, the Batoka Livestock Development Center in Southern Zambia is
also encouraging farmers and surrounding communities to invest in rain water
Bernard Muntanga is the Project Coordinator
of the Water Harvesting Project at the Batoka Livestock Development Center in
Choma. At one of the sites he says, "This
ditch…is actually supposed to be a reservoir. The purpose of this…is water harvesting.
We will have some… [pipes] on the roof then connect some poly [plastic or
rubber]pipes which come straight
into this ditch so that when rain comes it is collected from the roofs, then we
store it. During dry season we can still utilize it either through irrigation
or drinking water."
Sahelian Solutions is a non-governmental
organization that is promoting the construction of sand dams. They are
also used to store water for future use. The NGO has so far assisted Kenya's rural
communities in constructing 300 sand dams. The project is now being extended
to Zambia, Ethiopia and Zimbabwe.
Arjen de Vries is General Manager for Acacia
Water, and a water specialist for Sahelian Solutions. He says the aim of the sand dams project is
to improve access to water within Africa's rural communities. De Vries says in areas considered semi-arid
and arid, local people have problems dealing with constant drought for both
domestic and agricultural use. He explains how sand dams work.
"It's actually a very simple construction. I
mean it's an old technique. What people do is that they more or less block a
river bed containing sand. And they block it through construction of a concrete
type of dam. The whole dam fills up with sediment. The next rainy season the
water will be captured behind the concrete dam in the sediment. And because of
the sediment, the water will not be evaporating. From a water quality
perspective, it's not so susceptible to pollution," he says.
58 per cent of Zambia's 12 million people have access to clean
Due to global warming the periods of droughts
will even extend. Although the total volume of rainfall will not necessarily decrease,
studies show that the periods of rainfall will shorten. This is why development experts are
encouraging large scale investment in water harvesting facilities. This will
enable smallholder farmers and rural communities to have access to large
quantities of clean water.