SUSTAINABLE URBAN WATER SUPPLY MANAGEMENT: A CASE STUDY OF ADDIS ABEBA CITY, ETHIOPIA

Abstract

Water is a necessity for human survival, essential to socio-economic and environmental life. Addis Abeba is already dealing with physical and economical water shortage problems, which are exacerbated by the country's climate change and rapid population growth. The primary objective of this research is to develop a management strategy that will aid in the achievement of water protection and sustainability in Addis Abeba city using Water Evaluation and Planning (WEAP) model in conjunction with various socioeconomic and climate change scenarios. In addition, to make recommendations and guidelines for spatial planning, sustainable urban water supply, and demand management based on the outcomes of the evaluated scenarios. The study involves an assessment of water use, hydrological data, and climatic variables. The study results indicated that Addis Abeba has ten sub-cities and eight branches of water supply services, with the highest water demand concentrated in the Addis Ketema branch (269 Million m3), followed by Mekanisa (266 Million m3), Gurd Shola (227 Million m3), Gulele (218 Million m3), Arada (179 Million m3), Nifas Silk (156 Million m3), Akaki (102 Million m3), and Megenagna (85 Million m3) in 2050, respectively. However, if needed, water supply and demand management strategies and other necessary sustainability strategies are not implemented; the expected unmet demand in 2050 may reach about 1 billion m3. Data-driven models are appropriate for forecasting tools with their statistical criteria since they focus on analyzing data about a particular system. The mean monthly values of nine Global Climate Models (GCMs) of CMIP6 downscaled future climate scenarios (2021 to 2040) with 2.5 minutes spatial resolutions were used to forecast the projected models. The predicted data sets produce results two to three years ahead of time that fit well with the actual data, ensuring reservoir inflow prediction. The study revealed issues with water resource management, demand-side management approaches, and sustainable development challenges. As a result, the AAWSA must take immediate measures to identify new water sources, explore options for rainwater and stormwater harvesting catchment areas, and decentralize wastewater treatment generation for grey-water reuse to create additional water sources in order to meet growing demand.