How Traditional Water Wisdom Could Solve Modern Problems

By Alice Battersby

In our rapidly changing world, water – the excess or lack of it – is perhaps a greater concern than ever before. Climate change is making extreme weather events such as floods more frequent and unpredictable. Industrialisation has led to overextraction of many natural water resources, causing lakes and streams to dwindle, along with the nature and communities that depend on them. Agriculture requires water for irrigation, but too much water can be just as damaging to plants as not enough. Stephanie Kampf’s open access book, Hydrology for Sustainability, introduces these problems, and crucially, the ways they are being solved.

Of course, many of these methods rely on technology developed relatively recently. Fog harvesting, for instance, is carried out using a range of modern methods. Researchers have even taken inspiration from nature to create their designs. One type of beetle found in Namibia has a back made up of hydrophilic bumps separated by waxy hydrophobic surfaces. Water can condense on the bumps, and then fall into the waxy spaces between the bumps, flowing into the beetle’s mouth. Similar methods can be used for fog collection nets, where water condenses on hydrophilic bumps, and the drops fall down onto hydrophobic surfaces once they’re heavy enough, allowing collection. These innovations are fascinating, and can bring significant benefits.

What was particularly interesting to me, though, is the way that people throughout history and in different regions of the world have managed to work with water in clever and surprising ways. Their knowledge, developed over long periods of time through experimentation and practical experience, can be valuable to other communities seeking to work with their own water resources. Rather than forcing the water to behave according to human preference, these techniques often fulfil human needs effectively using what is available.

The contrast between these two approaches is perhaps most evident in the case of wetlands. Crops can’t grow if they don’t have access to oxygen. Waterlogged soil, as found in wetlands, fills the air pockets in the soil, making it impossible for most plants to survive, except for those with particular adaptations. If the land is to be used for agriculture, therefore, something must be done to give the plants oxygen access. One solution to this is wetland drainage, which has been carried out widely in places including northern Europe, India, East Asia, and southeastern North America.

But wetlands have advantages. In intact wetlands, the vegetation slows down surface water flow, allowing more of it to seep into the soil and contribute to groundwater, which is the ultimate source of many of our water resources. This slowing can also help with flood prevention, as downstream areas receive extra water more slowly, over a longer period of time, rather than all at once. Wetlands have other benefits, too; they can store large amounts of carbon, and can therefore play a role in the fight against climate change.

Is there a way, then, to allow agriculture to continue even in wet conditions? In fact, there are several. The Aztec city of Tenochtitlan was built on an island in Lake Texaco. To grow crops for the city, the inhabitants constructed smaller islands on the lake, called chinampas, using willow frames, vegetation, and lake mud. On the islands, there is enough soil above the water level for plants to get oxygen, but the plants still benefit from the water surrounding them, which is sucked into the soil and towards the roots. Trees are planted to keep the soil stable and to replenish organic matter over time. As well as this, the islands support flourishing ecosystems. Considering the sustainability and benefits of this type of agriculture, it is no surprise that evidence for similar systems has been found in Bolivia, Ecuador, Venezuela, and Colombia.

A similar method, used in Bangladesh, is floating agriculture. Much of Bangladesh is at high risk of flooding, something that an increasingly volatile climate will only worsen. One traditional technique for dealing with this is growing crops on floating islands in the flooded areas. These are constructed from rafts made of water hyacinth, bamboo, and organic matter. This has a similar effect to the chinampas: the plant roots do not become waterlogged. These gardens have the additional advantage that they can simply rise and fall with the water levels. Farmers grow many different crops on these islands, including tomatoes, beans, and potatoes.

The usefulness of looking at traditional methods is also clear when considering the crops that we choose to plant alongside each other. In mass agriculture, planting crops in monocultures is common, where only one type of plant is grown in each area. But using careful combinations of plants in an area to form a polyculture can bring benefits for both nutrients in the soil and water resources. The ‘Three sisters’ combination, used originally by Mesoamerican Indigenous groups, is a good example of this. This involves planting beans, squash, and corn together. Each plant provides benefits to the others: the beans fix nitrogen in the soil, the squash provides ground cover to prevent evaporation of water, and the corn provides shade and a trellis for the beans to climb. Comparing this to a monoculture of corn, less water is needed for irrigation, as there is less bare soil between plants from which water can evaporate. This therefore helps conserve water resources while allowing the same or better crop yields.

This isn’t to say that new, innovative techniques aren’t needed. But it does show that there is value in looking at the ways people have managed challenges before. Working with rather than against the present state of water in a landscape is in some cases both possible and beneficial, and using traditional methods may be one way we can try to do this. This could be a huge boon to many around the world, helping us all to face the challenges the future will bring.

Stephanie Kampf's book, Hydrology for Sustainability, is freely accessible online in PDF and HTML, and you can also buy a copy in paperback, hardback or EPUB.