RAIN WATER – A RESOURCE THAT MUST TO BE TAPPED TO ENHANCE FOOD PRODUCTION

RAIN WATER – A RESOURCE THAT MUST TO BE TAPPED TO ENHANCE FOOD PRODUCTION

About 80% of Kenya’s land area is classified as either Arid or Semi arid and possess a challenge in supporting agricultural activities. Some of the challenges affecting Kenyan Agriculture include climate change, which has drastically affected urban water system. A change in precipitation patterns towards more dry periods has led to food shortages that are currently affecting an estimate of 10 million Kenyans. The intense storms experienced when the rain finally comes have led to floods and surface runoffs resulting in erosion of the topsoil that is most viable for agricultural activities. Loss of soil fertility has then driven farmers to engage in massive destruction of forests and woodlands and other catchment’s areas to pave way for more productive farming.  Rather than allowing rainwater to flow over the surface of the earth and cause environmental disasters, such as landslides, floods and soil erosion, it can be harnessed for use in households, agriculture, and industrial use as well as for environmental improvement.  We often complain when we get dry spells, but we equally talk negatively when heavy rains pour. The climatic pattern in this country is predictable albeit to some extent.

Rainwater harvesting is the gathering or accumulation and storage of rainwater above the ground or charge it underground for future use. Extensive rainwater harvesting apparatus existed 4000 years ago in the Palestine and Greece. As early as the third millennium BC, farming communities in India, what was called Baluchistan impounded rainwater and used it for irrigation dams. In industrialized countries, rainwater harvesting systems have been developed for the purpose of reducing water bills, watering crops, or providing drinking water. Appropriate technology methods, such as solar water disinfections, provide low-cost disinfections options.

In countries as Uganda and Sri Lanka, for example, rainwater is collected from trees, using banana leaves or stems as temporary gutters; up to 50 gallons of water may be collected from a large tree in a single rainstorm. Many other countries are using sophisticated filtration and catchment tanks to benefit households or entire villages. Harvesting rainwater is growing in usage once more due to diminishing resources and an ever growing population.

Traditionally, rainwater harvesting has been practiced in arid and semi-arid areas, and has provided water that can be used for domestic, livestock and irrigation or commercial purposes and as a way to replenish ground water levels. This happens naturally in open rural areas. But in congested, over-paved metropolitan cities, we need to create methods to capture the rainwater. Rainwater harvesting is essential as surface water is inadequate to meet our demand and we have to depend on ground water. Due to rapid urbanization, infiltration of rainwater into the sub-soil has decreased drastically and recharging of ground water has diminished.  With limited water resources on the one hand and increasing demands for water on the other, there is a growing awareness to collect rainfall and make more efficient use of the water. Water conservation and development of alternative water supplies is thus necessary to meet our growing demand for fresh water.  

The two main techniques of rainwater harvesting: Storage of rainwater on surface for future use, and recharge to ground water.  The storage of rainwater on surface is a traditional technique and structures used were underground tanks, ponds, check dams, weirs etc. Recharge to ground water is a rather new concept and the structures generally used are: - pits, trenches, dug wells, hand pumps, recharge wells and recharge shafts.

The most basic example of a rainwater harvesting system would be of a rooftop collection. The water is collected and transported via ducts, pipes, or gutters. It is then filtered through a mosquito screen into a large barrel. A more complex example would be one used for potable water (drinking water). The water may be collected and diverted using the standard piping, but it is then filtered, often through sand and/or ultraviolet sterilization, and other filters. This technology is available locally. Along with the filtration process, there are a series of valves to aid in filtering and routing the water through the system. It may then be connected to the plumbing household fixtures for use within the home. Rainwater harvesting systems compliments water from wells and other sources, and, in many contexts, is often a more cost effective source of soft, high quality water.

            Rainwater harvesting technology is low cost and simple. It has a high potential of improving the living standards of millions of people especially them that live in dry areas by eradicating poverty and hunger, provision of safe drinking water and sanitation, ensuring environmental sustainability, promoting gender equity and women empowerment. Additionally, water scarcity especially for domestic and agricultural purposes compromises the role of women in food production. Hence, provision of water by promoting rainwater harvesting and management technologies reduces the burden for rural women thus increasing their productivity.

            Rainwater harvesting is an innovative alternative water supply approach anyone can use.  It captures, diverts, and stores rainwater for later use. Implementing the technique directly benefits our country by reducing demand on the water supply, and reducing run-off, erosion, and contamination of surface water. Strategies to effectively utilize the available water resources and rainwater should therefore be employed in an effort to achieve water security, which is a great leap in attaining food security. We are feeling the heat now but knowing that heavy rains are around the corner, let us think of harnessing the rainwater.