Many people ask us why at WaterHarvest, we harvest rainwater and why we don’t dig wells, sink boreholes or invest in piped water. The answer is that we believe that small scale rainwater harvesting structures are the best solution for families in the remote, arid and semi-arid areas that we work in. The reasons behind this can be broken down into the four main areas detailed below.
1. Small scale solutions
Small scale, rather than large scale structures are often a better solution for the communities we work with. For us this means we usually focus on one of the following water harvesting approaches which we can implement swiftly (once we have raised enough funds!):
- building a small number of harvesting tanks at individual schools (Uganda)
- renovating large dugouts used by remote villages (Ghana)
- building one water harvesting structure per household (India)
Large infrastructure projects typically rely on government for funding, implementation and regulation – the costs involved are high and they often take a very long time to come to fruition. The communities we work with are in remote locations and therefore unlikely to be the focus of any government infrastructure plans and they need urgent swift solutions.
The rainwater harvesting structures we build are given to each school, village or household to take ownership of – giving them greater control over the supply and quality of their own water. For example, they can improve the quality of the water by cleaning the inside of their tank and ensuring the roof gutter pipes are clean. They can also ensure they use the water carefully so it lasts until the next rainy season.
2. Environmentally sustainable
WaterHarvest only works in arid and semi-arid areas, that typically have low levels of ground water. With boreholes, the water is pumped out of aquifers that make up the ground water. When water is extracted faster than it is replenished, the aquifers soon become dry and the borehole or well can no longer supply water. Once this aquifer is depleted, the borehole then has to be deepened at considerable cost.
We have observed this many times in our work in India. For example, in one of the wells in the Sambhar Salt lake region, the water was just 40 meters below the ground in 1990. However, now 34 years later it is about 175m below ground level. Much of this is due to water being pumped out faster than it is being replenished but some is also due to changing rainfall patterns as a result of climate change.
Structures which catch and store the rain (i.e harvest the rainwater) and do not extract ground water, are therefore a more sustainable solution.
3. A better quality of water
The ground water in many of the areas that we work in often has high levels of salinity, fluoride and other pollutants. In contrast, rainwater is usually contaminant free. However, once the rain hits the roof and flows through the gutters and into tanks there is potential for contamination.
Our structures in India include a manual lever on the downpipe which enables families to direct the first rains (which are ‘cleaning’ the roof) to a separate container and then, once the roof is clean, directs the rainwater into the underground tank. Clearly this doesn’t remove all the potential contaminants, so our programmes in India also provide families with filters for use in the home to further improve the quality of the drinking water.
4. Low maintenance
As well as being more environmentally sustainable, being small scale and providing better quality water, the rainwater harvesting structures in our programmes require less maintenance compared with larger structures such as boreholes.
They are built using locally available skills and materials – the tanks we build at schools in Uganda are made with ecoblocks. As a result, they can be fixed locally, relatively inexpensively and quickly. One of the widely recognised issues with boreholes is the maintenance of the pump. Over time, pumps need maintenance and new parts. Getting specialists to fix broken pumps – and bring in spare parts- can be difficult. As a result, boreholes are sometimes unusable because the pump is broken.
Seeing it for ourselves
At WaterHarvest, over almost 40 years we have repeatedly seen for ourselves the benefits that these small scale, locally managed structures bring to socially and economically marginalized families and communities living in remote, semi-arid and arid regions.
