Estimation of Current Water Use over the Complex Topography of the Nile Basin Headwaters: The Case of Ghba Subbasin, Ethiopia

Abstract

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. This study aims to estimate the water use by different sectors, including water supply and irrigation sectors, by adopting estimated demand and supply water quantity. The current total population of the subbasin has been estimated to be 1.21 million. Thus, in the subbasin, current water use is estimated as follows: domestic and nondomestic water use in the rural area is 3.5 Mm3/year and 0.174 Mm3/year, respectively. The domestic water use of the towns is 12.77 Mm3/year. The industrial water use of the urban areas is 21.2 Mm3/year, whereas the commercial, public, and institutional water use are 1.87 Mm3/year. The real loss for all the water supply uses is 7.8 Mm3/year. Thus, the total current water supply uses are about 47.225 Mm3/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. The annual irrigation water requirements of these schemes are computed to be 151.55 Mm3. 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 Mm3 per annum. Hence, the total current water use estimate of the subbasin is 204.1 Mm3.

The Art of Sharing Resources: How to Distribute Water during a Drought Period

“…Ref. [9] studied the water allocation in Ghba Subbasin, Ethiopia. The authors estimated the demands of the sectors that use this resource the most and proposed a distribution based on this planning.…”

Future potable water supply demand projection under climate change and socioeconomic scenarios: A case of Gshba subbasin, Northern Ethiopia

“…Consistent urban and rural water supply demand forecasting is important for several reasons, including helping to make operational decisions for water utilities, helping to plan for future needs, and informing strategic decisions [1][2][3]. It is quite significant to know what the water demand for today and tomorrow will be in order to appropriately operate water supply systems such as; treatment plants, pipe network systems, reservoirs, and wells [4,5].…”

“…Normally, this is done in cases of drought. According to Hiben, Gebeyehu and Tabassum, Arsalan [16,17] water demand can be broken down into three categories: residential, commercial, and agricultural. Thus, water demand management (WDM) is a key strategy used to manage water resources throughout the zworld, as it ensures that all users have the water they need while conserving resources [18,19].…”

“…Water demand forecasting is a difficult task, because data is often limited and there are many variables that could affect demand [3,23,24]. For example, the data may be inaccurate because of the nature and quality of the data, and the variables that are thought to affect water demand can be very different from one forecast to the next [25][26][27].…”

“…The population projection for the proposed planning years was made based on Ethiopia's population was projected in the Central Statistical Agency Reports for the years 2014 to 2021 [39], Moreover, another strategic water resource management policy document (WRMP) created and approved by the Ministry of Water and Energy [40] as well as the study by [16]. The population projections for the planning period were made at the Kebele level using the projected growth rate proposed by the Central Statistical Agency.…”