Rainwater harvesting practices: A key concept of energy-water linkage for sustainable development

Abstract

Water shortage is a big problem in Ethiopia. The main challenge is to develop an appropriate and affordable innovation that can help to bridge the gap between demand and supply of water. Mostly, water supply plants are installed at a plain region, and Jimma zone of Ethiopia is a high land. Thus, water transportation, operation and maintenance of supply system consumes a big chunk of energy supply. The objective of this study is to evaluate the potential of rainwater harvesting and its suitability to meet the water requirements for Jimma zone, Ethiopia, besides to establish linkage between water and energy to achieve sustainable development. Rainwater samples were also analyzed to know the suitability of this water for different purposes. The important parameters analyzed were pH, EC, TS, TSS, TDS, DO and MPN. It was found from the analysis that rainwater harvested from roof-yard was quite safe for drinking purpose after chlorination, but the surface side rainwater was not suitable for drinking though it could be used for washing, cleaning and irrigation purposes. It was found in this study that 126,000 L of rain water could be harvested from a house having a covered area of 100 m2 in Jimma zone during kiramt season (rainy season). If this quantity of water gives a minor treatment and stored properly, it could be twice the water requirements for a family of 5 persons for a whole year, which could save a big share of energy in addition to water conservation and a key step towards sustainability of the environmental system. Key words: Harvesting, rainwater, energy management, sustainable development, water management.