Water Quality Determination of Rainwater Harvesting Birkas in Harshin District of the Jijiga Zone, Somali National Regional States, Ethiopia

Abstract

Harshin district of the Jijiga Zone Administration in the Somali National Regional State (SNRS) lacks ground water and surface water resources. In an effort to address the problems of recurrent drought, famine and food insecurity, attempts were made to harvest run-off water in cisterns (locally known as Birkas) for domestic and livestock use in the district. A study was carried out on 30 Birkas in three Kebeles in Harshin District to monitor quality of harvested water. The study found that EC, TDS, and nitrate in the study area are within the guideline value. However, 16.67 % of pH and 70 % of the measured turbidity are above the guideline value of 8.5 and 5 NTU respectively. Birkas that falls within the moderately hard water range were 86.7%. Of the total samples, 78.7 % exceed the standard COD value for surface water. Birkas with coliform contamination above the guideline value were 90%. Currently, rain water harvesting is the only solution for the severe water shortage problem in the community. However, considering the high bacteriological load and the higher pH and turbidity in the birkas it is essential to treat drinking water prior to consumption.

Keywords: Harvesting, Birka, Physical, Chemical, Microbiology