HomeOpinion & AnalysisColumnistsRain-water harvesting techniques for climate change adaptation, mitigation

Rain-water harvesting techniques for climate change adaptation, mitigation


The rainfall patterns in most parts of Zimbabwe used to be very encouraging and equally empowering. Nowadays, the situation is no longer the same as we experience suffocating dry spells with uncertainties on when exactly the rains would pay us the long awaited visit.

If by any chance the rains happen to come, they are often heavy, characterised by violent floods and run-offs that are destructive as well as life-threatening. The above mentioned forms of rainfall patterns may be successfully utilised in the form of rain-water harvesting for sustainable climate change adaptation and mitigation.

Despite having these rainfall and water potentials, Zimbabwe continues to face acute shortages of drinking water for both humans and animals. Zimbabwe also continues to suffer from agricultural growth and stagnation due to under-utilisation of the available water resources as well as its failure to harvest rainfall sustainably. As such, the realisation of the Sustainable Development Goals (SDGs) adopted in 2015, largely depends on the availability of water, as a result we might be found wanting in this regard. Furthermore, as climate change continues to present negative effects in Southern Africa and beyond, the increased pressure on scarce water resources continue to be felt and the telling effects are there for everyone to see. As a result of these manifestations, more practical and action-oriented approaches need to be implemented with utmost urgency for the future and the climate that we want.

Current obtaining facts and the situations on the ground point to the effect that, Zimbabweans are among the least responsible in water accounts and management issues, from the top to the common person. Our tradition of water misuse and underutilisation cannot be mystified as this is a living fact. Although the rains do not always come exactly when we will be expecting them, it might not mean that when they come we should not have anything to do with them. The absence and underutilisation of rain-water harvesting and conservation techniques amongst us, has left the nation very vulnerable to thirst and water scarcities, especially during the times of drought. Serious planning and sustainable solutions need to be harnessed so that Zimbabweans should change their approach in managing rain-water. A complete paradigm shift from a nation of watchers and marvellers of rainfall need to manifest itself in Zimbabweans so that we turn over a new leaf.

Rain water harvesting simply involves the process of collecting water from surfaces on which rain falls, filtering it and preserve it for later use. This water is normally collected from the roof tops and stored in rain-water tanks. The water can also be collected or harnessed from land water sources to constructed reservoirs, small or large scale. Rain-water harvesting can take place anywhere that is in towns, cities, rural areas and designated forest collection points. Previously, rain-water harvesting has been practised in arid and semi-arid regions of the world to amalgamate water shortages for human consumption and agricultural purposes. Communities such as ours (Zimbabwean), which previously did not practice rain-water harvesting on a wide-scale due to formerly abundant water resources need to be conscientised on how best they can seriously engage in this water saving technique.

When designing rain-water harvesting techniques, special emphasis should be placed on the risks and uncertainties of seasonal precipitation patterns as well as possible future climate scenarios. The choice of crops or plants also need to be taken into consideration with regard to the amounts of water to be used as well as their nature of resilience. Rain-water harvesting is a climate change adaptation or mitigation aspect aimed at ameliorating especially economic and environmental situations.
Rain-water harvesting apart from being an environment –ecological orientation, it can also be used to reduce the economic effects to sustainability. Rain-water harvesting for small scale nutritional gardens is fundamental in improving the nutritional value of households.

The heavy rains that hit Harare

Rain-water harvesting subscribes quite well to the concept of Integrated Water Resource Management (IWRM) which is a vital cog in water policy. Rain-water harvesting is not only about harnessing large amounts of water, it should particularly aim at improving the people’s livelihoods. The other aim is to reduce over-dependency on other traditional patterns and sources of water that are being fast threatened with the depletion in resource-levels as well as erratic shifts in seasons. Water reuse and recycling become other complementary issues that need to be practised for productivity. Rain-water harvesting is significant for community participation in order to increase the knowledge of water governance and capacity building issues.

Communities need to be taught how to construct sustainable water storage systems like small scale dams or reservoirs, wells and ground catchment cisterns in order to have adequate water reserves. Local NGOs well versed with the country’s landscapes and rainfall patterns should take leading roles in these initiatives. This is because rain-water harvesting is the only sustainable cost effective means available as ground water tables continue to dwindle.

Rain-water harvesting will also go a long way in reducing water-conflicts that are caused by selfish individuals who divert water illegally from flowing rivers into their gardens or plots to the detriment of other potential end users. Rain-water harvesting is also good for the protection and promotion of community orchards for cash crops and fruit trees plantations.
During these difficult times, people can increase their incomes, improve their nutrition levels, send children to school, pay fees and reduce drop-outs through selling agricultural products, fruits and vegetables.

Our major undoing as a country is that we always want to invest in mega-macro projects that are very difficult to implement, that also leave communities behind and have continuously failed. Why not encourage communities to engage in sustainable small-scale micro-projects that can go a long way in changing the people’s lives. It is also worrying to note that countries with a history of water scarcities such as Israel, Namibia and others have very good water conservation policies and have at the same time carried out thriving irrigation schemes while countries like Zimbabwe have lots of dams full of water but without any irrigation activities taking place.

●Peter Makwanya is a Climate change communicator. He writes in his own capacity and he can be contacted on: petrovmoyt@gmail.com

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