A natural pumping system for rainwater
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CTA. 2007. A natural pumping system for rainwater. Rural Radio Resource Pack 07/1. Wageningen, The Netherlands: CTA.
Permanent link to cite or share this item: http://hdl.handle.net/10568/57157
Transporting water uphill without the need for a pump ? a farmer explains his innovative system.
Cue: Thyolo district in the southern part of Malawi is very famous for its bananas which feed the whole of the district and the central region as well. It is also one of the two districts that grow tea. Tea growing is unique to this district because of, among other features, its mountainous features. In such an environment where most people grow bananas and tea, one innovative farmer, Friday Nikoloma, does something different, and is very successful. He traps rain water in ponds where he rears fish, and uses the same water to irrigate crops some two kilometres away. What is surprising, however, is that his crop fields are on higher land, and he manages to pipe the water to those fields without using any kind of pump or engine. Friday spoke to Patrick Mphaka about how he developed this system for transporting rainwater upland. IN: ?(Vernac) I thought about this for a ? OUT: ?without using a water engine, as I have done. (Vernac)? DUR?N: 5?01? BACK ANNOUNCEMENT: Friday Nikoloma, explaining his system for transporting captured rainwater to his crop fields without using a water pump, even though the crop fields are on higher land. The interview comes from a radio resource pack produced by CTA. Transcript Nikoloma (Vernac) I thought about this for a very long time. This being a hilly area, during rains there is a lot of runoff. So, I decided to dig ponds for fish farming, but also so that I could use the same water to cultivate other crops in uplands. The main challenge was therefore how I could make the water reach the upland from the lower areas without using a water engine. In the process of serious thinking, my mind focused on how water comes out of the ground through a spring. I remembered that at a spring, water gushes out of the ground with some force. I tried to think of how this force is created underground. I concluded that it happens because of the weight of the soil on top of a water body which forces itself on the water. The water then kind of escapes from this weight and forces itself out through a small hole we call a spring. I then seriously thought of what I would need to do to create the same scenario, where water would be forced to move from the low land to the upper land just as water comes out of a spring. I made an experiment where I directed the water into a hose pipe, but the water stopped flowing when it reached an equal level as that of the source. I thought of using a water engine to force the water to reach the upper land. But I also thought of the downside of this alternative; that the engine is expensive, and maybe I would never get a good return on my investment. So, I decided to keep on experimenting with just hosepipes. I discovered that when a lot of water is forced into a hosepipe and the hosepipe has a small hole, water gushes out of that hole with more force, for up to three or five metres high. This discovery gave me an idea that if the inlet is larger than the outlet, the water will come out with more force because the outlet is smaller. I then used a 5-inch hosepipe at the inlet, and connected it to a 3-inch hosepipe. In my connection, I found that water was coming out of the 3-inch pipe with a lot of force. I then connected a 1-inch hosepipe to increase the force. The result was splendid. The water was coming out of the smaller outlet with a lot more force and jumped to more than twice my height. I then decided that I should still direct this water into a hosepipe to determine the extent of reach. I found that the water was able to go upland but upon reaching a certain point, it stopped. I tried to find out why the water was unable to reach the desired point. I found that it was because I had bent the pipe. So, I let it go in a straight line for some distance and bent it later after some distance from the source, up there. But since this water was not in very large amounts, though the flow was continuous, I thought of constructing a holding tank upland. This would act as a head for more water for a better irrigation system. This worked well. This idea came up through experimentation when I discovered that there was a lot of water which was being wasted that would have been used in productive farming through irrigation, and again, when I did not want to use a water engine because it would be very expensive. I also wanted to demonstrate that we can use our brain and come up with useful innovations that can make water available where it would otherwise not have been available. Here, everybody has now seen that water can be moved from one place to another and enable irrigation farming. From these ponds, water goes to those hills where I irrigate maize, bananas, and other crops. I even direct the water into my extended family?s gardens to also enable them benefit from this water which is coming from a lower area. This is a demonstration to many people who live in the same conditions as mine, where the water is further away and in a lower area, where it can not flow through gravity. It is possible to direct this water upland and use it in many ways including irrigation without using a water engine, as I have done. End of track.
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