Enhancement of Small-Scale Runoff Harvesting Ponds in East Africa

Abstract

Ethiopia is one of the sub-Saharan African countries that is suffering from a recurring drought due to erratic rainfall occurrence both in amount and distribution. The livelihood of the largest portion of the people is dependent on rain-fed agriculture. Thus, crop failure is widely encountered by the peasants of the region because of the erratic nature of the rain and recurrent drought. As a result, millions of people depend upon relief assistance every year. It is therefore, necessary to detach the agricultural sector from its dependency on this seasonally fluctuating rainfall occurrence to supplement crop failure and feed the ever-increasing population of the country. This calls for harnessing runoff that occurs during wet seasons using water harvesting facilities and later use it in safeguarding crop failure through supplementary irrigation. Although harnessing runoff is not uncommon in Ethiopia, one of the major problems in this effort is the problem of excessive seepage losses and bank stability. This research work evaluates the methods that reduce seepage losses from ponds using locally available treatment materials. The treatment materials used were compacting the pond, lining the pond with termite mound and soil-straw mixture. These treatment methods resulted in reducing seepage losses and protected slope failure. soil-straw mixed and termite mound lined ponds contained water up to 47 and 43 days, respectively. This contrasts with the untreated (control) pond which contained water only for about 5 days. These methods are low-cost as local materials are used in the treatment and can be used in areas where seepage and bank stabilities are a problem. Moreover, this work is expected to pave the way for further research in the area.

Keywords: level-drop, pond, termite mound, treatment methods, water tightness

DOI: 10.7176/JNSR/9-16-01

Publication date: August 31^st 2019