Water leakage is like a worm in the water distribution system where the overall system may look healthy and working efficiently yet it is slowly sucking the life out of it. Water Loss Assessment (WLA) investigations have been done by many studies. It encompasses the estimation of the amount of WL of a specific site regardless of addressing the leaky location. At the beginning of the nineteenth century, WLA was based on “guess estimation” method than a precise tool [1
]. Recently, WLA and Water Loss Management (WLM) studies have been increased significantly. International Water Association (IWA) and the American Water Works Association (AWWA) introduced a new set of concepts and methodologies to improve WLA and WLM [1
Researchers and engineers have realized that WL is not about losing money but also water resources lost, which took time, money, and effort from the water network system and then distribution system [3
]. This is the initial loss of good quality water. Leaked water returns with contamination through the leakage point, which may itself raise a completely new issue [5
]. Safe distribution of water is the main motto of the water authorities. Leakage also raises questions on loyalty and reliability of the water supply system and their operationally and serviceability [6
]. WL is also about restrictive energy, clean water, supplying more water, and limiting carbon footprints going to the global population [7
]. Water loss is sought off as a common problem for the water utility system and a nuisance to the management [9
The most affected countries by water loss are low-income countries who cannot afford to lose any more precious water. In developing countries, the annual volume of non-revenue water (NRW) was estimated at about 45 million cubic meters in the distribution networks [10
]. The total cost was estimated at nearly 3 billion dollars per year due to WL. About 90 million people would be possible to serve by saving half of those losses [11
]. Nearly, 30 million cubic meters of water is delivered every day to customers, but are not invoiced because of pilferage, employee’s corruption, and poor metering [12
]. In low and middle-income countries, 60 million cubic meters of water was found to be lost daily through leaky pipes [10
]. In sub-Saharan Africa (which includes 46 countries including Ethiopia), NRW was estimated at around 600$
million per year from the distribution utilities. This significant portion of finding can help to estimate and accomplish the Millennium Development Goals in better-quality access to water and sanitation by the United Nations [13
Water loss in the distribution system has been reported, globally. WL of NRW is hard to estimate due to its incomprehensibility and faintness [14
]. The IWA task force and AWWA task force produced guidance and best management practice (BMP) strategies, respectively to ease the quantifying water losses and compare the effectiveness of their management policies [2
]. Leaky distribution systems increase the cost of water loss and affect adversely on water quality as well [16
]. There are many tools which came to existence to understand the water loss in the distribution system and to mitigate this confusing problem. A bottom-up approach, minimum night flow (MNF), and bursts and background estimates (BABE) analysis have been reported effectively to assess the water losses with excessive assumptions, accurate pressure measurement, and hydraulic model calibration, respectively [17
]. Therefore, these models are feasible for low-income countries like Ethiopia. Top-down is neither a pressure-dependent nor a total fieldwork-based method. The top-down approach requires data such as water balance and basic system data (water volumes, heads, and energy bills) to assess the percentage of water losses [19
]. The burst and background estimate (BABE) was accepted worldwide as it is a very easy and pragmatic approach to the complex and confusing problem of leakage in the distribution system [21
]. Reduced network models (RNM) was able to isolate leakage in the water supply networks, effectively. Comparison between the expected behaviour and actual measurement can be done to isolate the leakage [23
]. The first time in 2000, parallel computing recognized pressure reducing valves to adequately locate, to minimize the leakage problem in water network [24
WL consists of real losses and apparent losses [10
]. Real loss is also named as physical losses, which means it leaks out of the pipe by bursts and leakages. The apparent loss is also called commercial losses. Apparent water loss means consumer used the water without paying due to the meter being under review or registration, meter error, billing error, and data miss-handling. The amount of unauthorized consumption ‘Water used without bill’ is the main difference between NRW and WL [15
The water supply service in Kisumu (Kenya) and the national water company of Ghana lost half of its water supply due to WL. The state water board of Bache (Nigeria) estimated its loss may reach up to 75% in coming years, moreover this system was unable to calculate its total water supply due to the traditionally implemented system [1
]. Based on the study, results indicated that the total loss of water of Addis Ababa city was 54,094,795 m3
, out of 120,088,391 m3
supplied by the system and the loss was estimated to be 45% of the total supplied to the distribution system [28
As per the millennium, a development goal was targeted by the UN to achieve better practices in African cities in which Addis Ababa is one of them. Ethiopia being the second-most populous country of Africa and Addis Ababa being the capital, which is the fasting growing urban habitat. The problem was realized long before the urban water crisis and threatened water resources. During the initial study 40 percent of water was found uncounted [29
]. Ethiopia has progressed in the field of higher education, it had 33 public universities and 61 private institutes with overall 757,000 students by 2014 as per UNESCO Institute for statistic [30
]. To accommodate the huge population, there was a need for the large water supply and distribution system. When there is such a water supply system, there will be WL. More study is required in the case of real losses to figure out the reason of the loss and how it can be overcome and minimized, in context to developing and low-income countries where there is need of a low-cost solution and less expensive distribution system. In Ethiopia, water loss in higher educational institutions is a serious problem. However, adequate research has missed this issue so far. The estimation of the water loss is itself a challenge and it may arise in the case of improper water billed to the institute and water consumed within it.
This paper focuses on the calibration of different variables of water leakage of an educational institute (Ambo University, Ethiopia) such as quantification, addressing the components of WL, and fiscal loss in the location with predictive possibilities of water loss and revenue loss in the next four years in the study area. In addition, with some recommendations, that would assist to minimize the water leakage to save the natural resources along with energy conservation, which will help the government, organization, and the ecosystem. This study also opens another research objective with different variables for a different kind of institute or organization of the developing countries with a similar situation.
The next session describes briefly the study area and the subdivision of the blocks where the assessment has been done. The third section deals with methods to evaluate the quantity of leaky water, localized loss comparison, cause of water loss, revenue loss, and future prediction (up to 2023) of water loss and economic loss. The fourth section discusses and analyses the resulting outcome of the finding using the methods described earlier. The last part is the recommendations which deal with, how to lessen the water loss with different contemporary techniques such as awareness among consumers, localized physical measurement, and use of AI models.
This work would help to reduce the problems of water leakage and to understand the reasons of it explicitly why, how, and where water leakage is taking place commonly in the system. The average water demand was evaluated as 125.2 LPCD (liter/capita/day) and 177.4 LPCD in 2017 and 2018, respectively. This average per capita consumption was more than the country standard, used for design purpose and that is 30 to 60 LPCD as per Ethiopian Building Code Standard (EBCS) 9 in respect to the revenue lost 42,575 Br and 42,664 Br or in 1562$ and 1566$ in 2017 and 2018, respectively. This study is the alarm for the managing authorities that it is time to understand that water is more valuable than time and money in the present crisis. In many illustrations, the problem of water loss is caused by poor operational practices, poor infrastructure, network characteristics, and bad management practice. In addition to the lack of different time scale data, periodical maintenance, and lack of motivation at the management level. Thus, the IoT, Ambo University water authority has great difficulty to locate the WL and quantifying it precisely. Thus, it is suggested that the well plan periodic management can overcome most of the issues as recommended in the previous section. Ethiopia is considered as a water-stressed area since water is there but not fit for drinking because of this, health issues are also increasing day by day. The study aims to increase awareness among the authorities of the area as well as similar areas where a large amount of water is wasted because of human ignorance and lack of awareness.
UN project is very much active in these areas and therefore, sustainable development goals approach needs more effort to reach and water leakage mitigation may help to achieve it. Uniform price policy does not bring social justice among different kinds of consumers as well as nothing that benefits the operator [54
]. This study has used the top-down approach because of its simplicity in leakage assessment for such areas where there is lack of available and continuous data, obliviousness in preservation and management, which lead to lack of information in a specific occasion. However, this was the first step for the leakage study and more research has to be done considering the issues and problems in a developing country. Similarly, BABE was used because it does not use the holistic approach rather it uses the individual point source data collection system, which was more suitable in the case of this study because of lack of differentiated distribution system and lack of data. This paper’s target area was to study the environment and take simple measures which can save lots of potential water and could be implemented commonly for developing areas similar to such. The initial target was taken as an institution because they have habitat of a large population, mostly funded by the government, and managed by common authorities.