provisão de água DIY: as vantagens do auto-abastecimento
Em alguns contextos, melhorias incrementais no abastecimento de água podem oferecer maior sustentabilidade do que intervenções completas. Mark Fabian, Consultor Técnico Regional para a África Austral, descreve os pontos positivos comprovados do auto-abastecimento.
In the water, sanitation and hygiene (WASH) sector, we see countless methods for delivering safe water to households, varying from simple to complex. Management models can be as complex as the technologies to deliver water, and we see communities constantly struggling with ways to manage and maintain water points, especially when external support is minimal.
In August 2016, the WaterAid Southern Africa Regional Office broadcast a webinar to the WaterAid community on self-supply, highlighting research coordinated by Andre Olschewski of SKAT Foundation. Andre highlighted two case studies – one in Zambia, and one in Zimbabwe. In the webinar, we also heard Michael Ngoma, Provincial Programme Manager at WaterAid Zambia, discuss the self-supply work done in Zambia. You can find a synthesis of the self-supply work Andre led here, and a summary of a presentation done on self-supply in Ethiopia here.
What is self-supply?
In simple terms, self-supply can be defined as self-financed incremental development of water points. Particularly in rural areas, where populations are too small to warrant municipal or externally funded water sources, communities often finance their own water supply.
This is often in the form of a dug well, which originally may not have been what we in the WASH sector would define as an improved water source, mostly because it might not be protected from contamination. However, with incremental improvements to this dug well, the simple water source can be improved to be reliable and safe and offer a high degree of convenience and service. For example, dug wells can be improved with the addition of an impervious cap which keeps out surface water and other contaminants, and of a lifting device such as a hand pump or a windlass.
Communities around the world use this form of incremental water source development all the time. It does require financial input to develop the infrastructure, but, because the work is incremental – and community members can combine financial, material and labour resources – the source can be quite affordable per-capita.
For many people in developing countries the self-supply approach is just one step on the way up the ladder. However, for many people, the lack of alternatives and lack of funding will still mean this is their only supply.
In some cases, a community receives support from government or another external actor to achieve self-supply. This is called supported self-supply, and could be an excellent option for communities that cannot afford the upgrades completely on their own. Important elements that should always accompany supported self-supply are promotion of hygiene behaviour change, and household water treatment to ensure the potability of the water.
Another example of self-supply is an ad-hoc gravity water system, where residents use their own funds to insert a pipe into a stream or spring above their residence and run pipes down to tap stands and residential installations.
After the initial installation, the community may introduce a simple household treatment of the water, or even a simple chlorine injector, to make the water potable. They may also add a dam, filter, and sedimentation facility at the source, in order to further improve the water quality. Little by little, the simple gravity water system can be made more and more safe.
What are the advantages?
The research in Zambia on self-supply showed that faecal coliform contamination was not higher in water from self-supply water points than in water from boreholes; in fact, self-supply wells were just about as safe. This speaks to the efficacy of protecting a well using simple incremental improvements. The figure shows that the most contaminated water sources sampled were unimproved wells, and that the wells improved through self-supply were generally not contaminated.
The implications of the success of the self-supply method are encouraging – some rural communities with limited means can improve their own water supply and get safe water all on their own. The role of water specialists such as WaterAid is then to help provide the technical support to communities to instruct them on how to improve their own water sources. While I am not saying Governments do not have a responsibility to rural citizens, self-supply does offer a solution in areas where governments do not currently have the means to intervene.
Thus, while many of us in the WASH sector may have previously believed that safe, potable water can only be delivered to communities through external or municipal support, it is really apparent that, in some cases, all we may need to do is help communities learn a do-it-yourself method. Of course in many contexts, delivering water to communities is just too expensive or otherwise difficult for this approach. For some, however, self-supply is an intriguing solution.