In early October, we travelled down to GH11 - a remote Wildlife Management Area located west of the Central Kalahari Game Reserve - where we installed the first of 10 Portable Rainwater Harvester ("PRH") devices we've manufactured so far this year, from sponsorship received from the Comanis Foundation. The PRH device (our own invention) will provide vulnerable, water-stressed communities with an extremely useful adaptive coping mechanism, at a time when the effects of global climate change are already showing signs of accelerating. One of these devices can yield enough drinking water to sustain up to 11 people for a year, at annual rainfall as low as 350mm (typical drought condition). Its effectiveness lies in its ability to efficiently capture any amount of rainfall and protect it from contamination and evaporation - a critically important feature, considering that evaporative water loss in Botswana often exceeds 2000mm per year!
Amongst its mutiple benefits, the PRH will help the San and other similar communities by facilitating their access to useful natural habitats - situated away from the settlements - that are still unaffected by livestock overgrazing, as well as those areas that are naturally richer in supplies of wild plant food species. Such areas have become difficult to access due to the lack of surface water and the required travel distances, as compounded by the difficulty in transporting drinking water, which makes it extremely impractical to undertake effective gathering expeditions for effective plant food harvesting.
Rural settlements and cattleposts - where water supplies are currently located - are characterised by widespread overgrazing by livestock and the depletion of most of the surrounding natural plant food resources on which the original occupants of these areas historically relied, thus compounding dependencies on foodstuffs sold in local shops, which are typically too pricey to be accessible to most residents and at any rate are extremely limited in variety and deficient in essential vitamins and minerals. By contrast, over 100 species of wild, drought-tolerant, plant food species are potentially available for use in natural Central Kalahari habitats, often with nutritional qualities far exceeding that of processed foodstuffs.
The PRH therefore has the potential to impact positively on the food security of many struggling and malnourished rural dwellers, in particular the San. It also has good potential for promoting the preservation of traditional knowledge and culture through skills transfer and as a water supply alternative for remote tourism operations in dryland areas where potable ground water extraction is prohibitively expensive and impractical. The primary advantage however lies simply in improving the overall reliability and supply of clean drinking water for people - wherever they may live - and in freeing water-stressed communities from their current over-dependence on centralised water supply points that are costly to maintain and ultimately unsustainable due to the lack of recharge taking place in the deep fossil underground water acquifers they extract from.
The PRH essentially dramatically reduces the daily personal health risks and energy expenditure involved in accessing conventional, centralised water supplies as users can install it at optimal and conventient locations (e.g. right where they live) and it empowers users to independently manage - by way of a single device - their own drinking water provision, on an ongoing basis and from source through to supply.