Research Article Estimation of Current Water Use over the Complex Topography of the Nile Basin Headwaters: The Case of Ghba Subbasin, Ethiopia Mehari Gebreyohannes Hiben , 1,2 Admasu Gebeyehu Awoke, 1 and Abraha Adugna Ashenafi 3 1 School of Civil and Environmental Engineering, Addis Ababa University, Addis Ababa Institute of Technology (AAiT), Addis Ababa, Ethiopia 2 MG Water Resources Consultancy Firm, Mekelle, Tigray, Ethiopia 3 Ministry of Water and Energy, Addis Ababa, Ethiopia Correspondence should be addressed to Mehari Gebreyohannes Hiben; hiben123@gmail.com Received 26 April 2022; Revised 3 July 2022; Accepted 11 July 2022; Published 8 August 2022 Academic Editor: Yizi Shang Copyright © 2022 Mehari Gebreyohannes Hiben et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Quantifying the available and useable water is critical work in any water resource study and design project. However, it is challenging to provide a robust and accurate estimation of water use and distribution for better water resource management and planning. is study aims to estimate the water use by different sectors, including water supply and irrigation sectors, by adopting estimated demand and supply water quantity. e current total population of the subbasin has been estimated to be 1.21 million. us, in the subbasin, current water use is estimated as follows: domestic and nondomestic water use in the rural area is 3.5 Mm 3 / year and 0.174 Mm 3 /year, respectively. e domestic water use of the towns is 12.77 Mm 3 /year. e industrial water use of the urban areas is 21.2 Mm 3 /year, whereas the commercial, public, and institutional water use are 1.87 Mm 3 /year. e real loss for all the water supply uses is 7.8 Mm 3 /year. us, the total current water supply uses are about 47.225 Mm 3 /year. From the existing irrigation schemes, about 10,254.8 ha areas are irrigated by both smallholders and different investors, growing vegetables, cereals, and fruit trees. e annual irrigation water requirements of these schemes are computed to be 151.55 Mm 3 . Livestock water demand of the subbasin was assessed and estimated based on the population and consumption rates of the species. Currently, the subbasin has a total livestock population of 1,527,835, and the water demand of which is estimated at 5.3 Mm 3 per annum. Hence, the total current water use estimate of the subbasin is 204.1 Mm 3 . 1. Introduction e rapid growth of the population is causing an alarming demand increase in freshwater resources (e.g., lakes, rivers) of the world [1–3]. Continuously people who are living in different states or even within the same boundary are cre- ating conflicts over water that they withdraw from common sources, often and even decades pass by, but such water disputes are not resolved [4, 5]. Water use is often metered in all other sectors except in the agricultural sector. In this paper, we examined a case study of current water use estimates in the Ghba subbasin using geographical infor- mation system (GIS) and collected data. Several studies, e.g., [6–8], have applied the same techniques for the estimation of agricultural water use using GIS and collected data. Before the assessment, the study briefly reviewed FDRE Constitution [9], Water Resources Management Policy [10], Water Resources Management Proclamation [10], Water Resources Management Regulations [10], Nile Basin Ini- tiative Reports [11], Central Statistical Agency Reports forecasted the population of Ethiopia from 2014 to 2017 [12], and another related strategic document of water resource Hindawi Advances in Civil Engineering Volume 2022, Article ID 7852100, 14 pages https://doi.org/10.1155/2022/7852100