ABSTRACT
It is crucial to provide sufficient and potable water to ensure a healthy society and promote a country's development. Unfortunately, many towns in developing countries, including Dangila town, experience prolonged water shortages, leading to various socio-economic challenges for residents. This study aimed to assess the performance of Dangila town's current water supply system. To achieve this objective, different secondary data were collected from various sources. The average per capita water consumption was 15.78 l/day, which did not meet the Millennium Development Goal (MDG) and Sustainable Development Goal (SDG) standards. The estimated average water supply coverage was 46.37%, failing to meet the MDG target and the SDG. Non-revenue water ranged from 1.81 to 92.95%, with an average of 36.81%, exceeding the maximum limit set by the World Bank. This research also discovered that if non-revenue water is well managed, 267,192 people could be supplied, assuming a per capita demand of 50 l/day. Therefore, this research concluded that the water supply system did not meet the minimum national and international water supply standards, indicating its poor performance. Thus, it is crucial to implement continuous, well-planned, and organized maintenance, operation, monitoring, service management, and scientific loss control, along with water source development.
HIGHLIGHTS
Dangila town's current water supply system performance has been assessed.
Non-revenue water was found below the required standard.
Per capita water consumption and supply coverage did not meet the standards.
Non-revenue water could potentially supply 267,192 people, assuming the per capita demand of 50 lcap/day.
Continuous system maintenance, loss control, and source development are essential.
INTRODUCTION
Water is crucial not only for humans but also for all living organisms (Kılıç 2020). Access to improved and clean water supply is one of the key factors significantly contributing to the socio-economic development of a country. It helps to improve the lifestyle, health, and productivity of society (Mugagga & Nabaasa 2016). Water is essential for life, second only to air in importance. While human beings can survive several weeks without food, they can only survive a few days without water. This is because the body requires a continuous supply of water to replace fluids lost through physiological activities. Water is just as important as air in sustaining the vital processes of life. It makes up about 60% of the human body's weight. Water is used for several purposes by people, and it must be of acceptable quantity, affordability, equity, availability, and quality for human consumption (Egbai et al. 2013).
Thus, providing clean, adequate, affordable, and safe drinking water to people at the right time is crucial for the development of a healthy and productive society (Okafor et al. 2024). Therefore, water supply systems need to deliver sufficient and uncontaminated water to users as per their design. Unfortunately, many water supply systems in the world do not function according to their design and deteriorate quickly, leading to water shortages and various problems for the population (Cosgrove & Loucks 2015). For instance, even though the water supply coverage is better in urban when compared with rural, the actual water supply coverage in municipalities of developing countries in broad and African metropolises specifically is very low when compared to the demand. As the World Health Organization and United Nations International Children's Emergency Fund assessed in their Joint monitoring program in 2015, 58% of the population accessed drinking water from improved sources through house connection and yard mode of services, and 33% of the population from other enhanced sources. However, 663 million people in the world lack access to an enhanced water source (WHO & UNICEF 2017). In the last two decades, investment in drinking water services has led to considerable increases in access. Two billion people globally gained access to safely managed drinking water services. In 2020, 74% of the world's population used safely managed drinking water, up from 62% in 2000. Despite this progress, there are wide geographical disparities, and 2 billion people still do not use safely managed drinking water (WHO &UNICEF 2022). According to the global water supply and sanitation assessment report which is carried out based on the mode of services, African capital municipalities had 43% house connection and yard taps, 21% had public taps whereas 31% of the population is unserved (World Health Organization 2000). The Federal Ministry of Water and Irrigation has reported that access to basic water services in Ethiopia is only available to 50% of households, despite experiencing a 32% increase in coverage from 2000 to 2016. Currently, 24% of households use unimproved water sources, while 11% rely on surface water (Supply & Sector 2019). Because of this, the lack of access to clean water has resulted in an increase in waterborne diseases, which has led to social instability, decreased productivity, and as a result, poverty and starvation (Meride & Ayenew 2016).
Water supply systems are crucial public infrastructures, but they can be expensive to maintain. The main goal of a water supply utility is to ensure that the system operates as efficiently as possible at the lowest cost over its lifespan (Haider et al. 2014). Water distribution networks are essential for both rural and urban communities (Nouri et al. 2015). The aim of a water distribution system is not only to maintain water pressure, but also to deliver high-quality water that looks, smells, and tastes good, and is safe to drink (Adedoja et al. 2018). However, small and medium-sized water supply systems face specific performance-related challenges, including difficulties in collecting necessary data for performance indicators, as well as a lack of skilled personnel and financial resources for efficient operations (Haider et al. 2014). One of the main reasons for the inefficiency of water supply systems is improper system design. In many cases, the water demand components are not estimated or forecasted accurately (Alegre et al. 2016). To predict future domestic water demand, empirical models are often used based on the growth pattern of the town, without considering factors such as nature, type, number, pattern, and future development (House-Peters & Chang 2011). For non-domestic water, a certain percentage of the domestic water demand is taken without considering these factors either. Thus, after one year or less, the demand and supply imbalance happens in most of the water supply systems in this case. Among a variety of factors, the groundwater sources that urban centers rely on for their domestic and industrial needs are becoming depleted from time to time (Asgedom 2014). This problem is further intensified by the rapid pace of population growth and the expansion of the city, along with frequent electric power outages, which lead to inadequate water supply. The water supply utility drills additional boreholes every year, but some wells are going out of use (Asgedom 2014).
The second reason for the inefficiency of existing water supply systems is poor maintenance, monitoring, and faulty construction. As attention is focused on improving access to water supply for the population, maintenance, and monitoring are often neglected (Farok 2016; Żywiec et al. 2023). This leads to a loss of a huge volume of water in the existing water supply systems and residents going without water supply. Another major reason for inefficiency is the decay of system components. The water system components lost their performance as their age increased gradually (Yi et al. 2017). The study conducted indicated that the water supply in the North and Central-West regions presented high loss rates, 43, and 37% in this case, respectively (Santos et al. 2018). In addition, the research carried out in 2019 revealed that 60% of the water produced has been lost due to poor maintenance and monitoring (Bhagat et al. 2019).
One of the factors that affects the efficiency of a water supply system is the unaccounted-for water. This is the water that is lost between the point of supply and consumption due to various reasons (Shilehwa 2013; Aho et al. 2016; Rajasekhar & Ramana 2018). Non-revenue water (NRW) is an important component of commercial water system management. It is the result of pipeline leakage, illegal service connections, unbilled authorized consumption, and theft of water (Farok 2016). NRW is uncounted water that has been produced but it is confirmed to be lost before it is consumed by the customers. This matter agitates all concerns and especially it affects the whole economy (Farok 2016; Murugan & Chandran 2019). Following are the three components that contribute to NRW: physical or real loss commercial or apparent loss and unbilled authorized consumption (Rajasekhar & Ramana 2018). Physical or real loss occurs as a result of burst pipes, loss of pressure, pipe leaks in the distribution network, and overflows from service reservoirs (Zewdu 2014; Gwoździej-Mazur & Świętochowski 2021). This type of loss caused due to poor operations and maintenance, a lack of active leakage control, and poor quality of underground assets (Murugan & Chandran 2019; Yekti et al. 2019). On the other hand, commercial loss happens due to customer meter under registration, data handling errors, unbilled metered water, unmetered public use, illegal connections, and theft (Zewdu 2014; Al-washali et al. 2016; Farok 2016). The third component, unbilled authorized consumption includes water used by the utility for operational purposes, water used for firefighting, and water provided for free to certain consumer groups (Murugan & Chandran 2019). It is important to consider three types of NRW when designing and maintaining a water supply system (Figure 1). Due to this, 60% of the world's population does not have access to water. According to the study conducted by Abebe, NRW accounts for 39.68% of the total volume of water produced and distributed to the system. The study also revealed that 60% of the loss is physical (real) and the apparent loss covers 40% (Abebe 2017).
The average NRW figure in terms of percentage is 40% across the whole Africa (Anon 2015). A study conducted in Nigeria revealed that the level of NRW ranges from 36 to 50% (Nasara et al. 2021). The global volume of NRW has been estimated at 346 million cubic meters per day, or 126 billion cubic meters per year, amounting to a financial loss of approximately USD 39 billion annually (Science et al. 2020). Furthermore, research indicates that 50–60% of treated and supplied water is lost during transmission from water service reservoirs to customer service connections (Rajasekhar & Ramana 2018).
In a study carried out in Hyderabad, India, it was found that real losses comprised 42% of the total system losses, followed by apparent losses at 34% and unbilled authorized consumption at 24% (Rajasekhar & Ramana 2018). In Kazerun, it was estimated that out of 12,995,619 cubic meters of water produced annually, the rate of NRW was approximately 5,011,084 cubic meters, representing 38.56% of the total volume produced. The highest proportion of NRW was attributed to real losses (22.88%), while apparent losses accounted for about 14.4% and unbilled authorized consumption was about 1.3% (Kamani et al. 2012).
According to a study by the Asian Development Bank, NRW in Asia was estimated at 78,292,500 cubic meters per day, which is 28.7% of the total system input volume of 267,550,000 cubic meters per day. This loss translates to a cost of approximately USD 8.6 billion per year. Of this total loss, 21.4 billion cubic meters per year were attributed to physical losses, and 7.3 billion cubic meters per year to commercial losses (Asian Development Bank 2010).
In addition, climate change and socio-economic activities will affect the water resources system, which causes a decrease in water supply that affects the urban water system (Ougougdal et al. 2020). Among the most important impacts of climate change are the rise in surface temperature, the reduction in precipitation (Stocker et al. 2014), and declining water quantity and quality (Trenberth et al. 2015). It is estimated that more than a third of the world's population approximately equal to 2.4 billion people in 2000, live in countries under water stress and this will rise to two-thirds by 2025 (Vörösmarty et al. 2010). Climate change, population growth, and economic activities are leading to water scarcity, an unpleasant situation in which the demand for water increases beyond the water supply (Hoekstra et al. 2012). The research results also show that water demand and the unmet water demand will increase in all scenarios, the pressure on water resources will increase, leading to water scarcity. The results reveal that, under the influence of climate change, future unmet water demand is expected to reach 64 million cubic meters by 2025 (Ougougdal et al. 2020).
Due to the above mentioned and other reasons, many people around the world do not have access to clean and safe drinking water. This problem affects both rural and urban populations. For instance, only 16% of people in sub-Saharan Africa have access to clean drinking water (Emenike et al. 2017). In fact, water scarcity is becoming one of the biggest challenges facing many countries, hindering their economic and social development (Shevah 2015). Africa has the lowest water supply coverage of any region in the world. Currently, over 30% of people living in African urban areas do not have access to adequate water services and facilities (Dos Santos et al. 2017). In 2000, the World Health Organization estimated that 28% of the world's population was without access to improved water supplies in Africa. Only 62% of people in African countries have access to improved water supplies (World Health Organization 2000).
Even if Ethiopia is known by its huge water resource potential, access of potable drinking water supply coverage in the country is amongst the lowest in sub-Saharan Africa as well as the entire world which is 57.3% in 2015 (Ruducha et al. 2017). Most of the towns in Ethiopia have encountered a problem of adequate and potable drinking water supply (Akkaraboyina & Desta 2018). During the milinium development goal, the country water supply access coverage increased from 14 to 57% (Supply & Programme 2015). Access to at least basic drinking water increased only by 7.5% over 6 years, from 42.1% in 2015 to 49.6% in 2020. Ethiopia is one of the countries that may be considered off track on the pathway to meet the 2030 drinking water sustainable development goal (Baye 2021).
Dangila is a town in Ethiopia that has been facing difficulties with providing sufficient quantities of clean and safe drinking water. Despite installing a water supply system in 1977, which has been expanded over time, the demand for clean water is not being met. Many residents do not have access to enough clean and safe drinking water, and there are frequent interruptions in the water supply system. Currently, residents only receive water once every one or two weeks, which is inadequate for daily activities. As a result, they are forced to travel far from their homes to obtain water or buy it at an additional cost. The shortage of water has caused various problems for the community, such as using alternative sources that may not be safe for drinking. This has led to waterborne diseases and worsened the overall health of the population. Therefore, a study was conducted to evaluate the performance of Dangila town's existing water supply system and investigate the current situation in the water supply system.
MATERIALS AND METHODS
Description of study area
Population
Based on the national population and housing census conducted by the Central Statistical Agency of Ethiopia in 2015, the estimated population of the town was 24,827. The populations of the town before this census in 2011, 2012, 2013, and 2014 were 10,301; 12,835; 15,992; and 19,926, respectively. However, as per the latest official projection carried out by the mayor's office in 2020, the town's population had increased to 82,654 with an annual growth rate of 2.46%. The latest projections in 2016, 2017, 2018, 2019, and 2021 were 34,293; 42,739; 53,240; 66,336; and 102,987, respectively, according to the mayor's office.
Existing water supply sources and water demand
The town's water supply is sourced from deep wells. The first well, named DW3, was drilled in 1985 in Kebele-05 and had a yield of 3 l/s. Eight years later, in 1993, a second well named DW4 was constructed in Gagita with a yield of 2.5 l/s. As the town's population grew, three additional water sources were drilled from 2005 to 2010 in Berayta. They are named DW1, DW3, and DW4, with yields of 18, 20, and 20 l/s, respectively. With all these sources combined, the town's water production is approximately 63.5 l/s under normal conditions.
In the minimum development goal (GTP-1), the minimum per capita water demand standard was 20 l/day for urban areas and 15 l/day for rural areas. However, in the sustainable development goal (GTP-2), the country's minimum water demand standard is classified into six categories based on administrative levels. According to, the universal access plan, the minimum water demand is 100 l/day for category-1, 80 l/day for category-2, 50 l/day for category-3, 40 l/day for category-4, up to the premises distance of 250 m, and 20–25 l/day for category-5 and category-6 towns within a distance of 500 m with a piped system for 75% of the urban population.
Study design
The study aimed to assess the performance of Dangila town's existing water supply system and investigate its status from December 2023 to January 2023. Due to resource and time constraints, only five water supply system performance indicators were used for this research. These indicators include water production, consumption, NRW, supply coverage, and actual per capita demand. The evaluation of the town's current water supply system was based on these performance indicators for the entire existing water supply system.
Data sources and collection
The data used for this research were gathered from various sources. Seven years of annual water production and water consumption secondary data were collected from the town water supply and sewerage service office. Population data for the town over the consecutive years was obtained from the mayor's office. Various national and international plans and goals related to water supply were also downloaded from Google. Additionally, the national water supply access plan, urban water supply policy and guideline, official statistics, and reports available in water projects implementing agencies' offices were utilized. Furthermore, relevant published journals which were downloaded from Google for this research was used.
Water production and consumption
The total annual water supply to the water distribution system was evaluated as the water production. The town's water production is sourced from three boreholes managed by the Dangila town water supply and sewerage service office. These deep wells were designed with a combined water production capacity of 63.5 l/s and operated for an average of 18 h/day. Water bills are issued by the Dangila town water supply and sewerage service office to collect revenue from the customers. To determine the average water consumption, the annual total consumption was divided into domestic and non-domestic water usage. As outlined in the urban water supply universal access plan from 1990 to 2015, the minimum water quantity required is set at 20 l/person/day for domestic use, with non-domestic consumption estimated at 30% of the domestic usage (MoWIE 2002; MoWE 2013).
Non-revenue water
Water supply coverage and average consumption
Data analysis and reliability
The quantitative data regarding water consumption, water production, water loss, per capita water consumption, and water supply coverage were analyzed using Excel software. Additionally, the relationship between water supply performance indicators was examined using the Pearson correlation coefficient in SPSS software (version 21). The analyzed data were presented and interpreted using both tabular and graphical methods. In terms of population data, there has been a significant migration of people from rural areas to the town. However, the mayor's office did not account for this migration in their projections, which may result in certain uncertainties in the population data regarding water usage in the town.
RESULT AND DISCUSSION
Water production
Trend of water production, consumption, and NRW in Dangila town (2011–2021).
The research conducted in a town similar to Dangila town found that the annual water production in 2017 was 68,916 m3, which is lower than in any other year of water production in the target town. This study also found that the water production one year later (2018) was 89,928.7 m3, which was also lower than in any other year of water production in the target town (Mekuriaw 2019). However, this research also reported that the water production within the two years indicated an increasing trend, similar to that of the studied town, except for the year 2012.
The research conducted in Boditi town from 2007 to 2013 reported that the water production varied between 167,076 and 231,309 m3/year, which is lower compared to the water production rate of the studied town, but it indicated an increasing trend (Abate 2016). Asgedom (2014) reported that the water production rate from September 2008 to August 2009 in a larger town from the studied town was 4,207,059 m3/year, which is greater than the water production rate in the years from 2011 to 2016 and lower than in the years from 2017 to 2021. In general, the overall average value of water production in the target town was 5,019,186.94 m3/year, which is greater than that of similar and larger towns in Ethiopia.
Water consumption
In 2011, water consumption was estimated at 841,434 m3. The following year, it significantly increased to 1,625,425.56 m3 (Figure 3). This might be due to the connection of new sources to the existing water supply sytem and service management. However, from 2012 to 2013, there was a sharp decrease to 149,196.89 m3. This sharp reduction was because of the high increase in unaccounted-for water and poor service management. Subsequently, in 2014, there was a substantial increase to 1,699,116.85 m3 (Figure 3). The substantial increase in the water consumption in this year (2014) was as a result of the planning and implementation of NRW reduction program together with the introduction of new sources to the system. This trend continued with an increase to 3,395,659.49 m3 in 2015. The trend reversed by decreasing to 3,067,663.01 m3 in 2016. This reduction of water consumption was owing to the negligence of water supply system monitoring and then an increase in system loss. However, in 2017, there was an increase to 3,535,388.92 m3, followed by 4,771,659.9 m3 in 2018 and a further increase to 5,802,657.1 m3 in 2019 (Figure 3). This might be due to the re-start of water supply system monitoring and maintenance and then the reduction of NRW in the respective years. Yet, there was a decrease to 4,267,014.14 m3 in 2020, followed by an increase to 6,671,755.89 m3 in 2021 (Figure 3). The decrease in water consumption in 2020 might be due to the increase of unbilled water consumption groups in the water supply system in the town. The lowest water consumption was in 2013, and the highest was in 2021. Overall, from 2011 to 2016, there was a fluctuating trend, followed by a gradual increase from 2016 to 2019, and then a mixed trend from 2019 to 2021(Figure 3).
The research carried out in a similar town indicated that annual water consumption in 2017 was 54,870.9 and 68,346.2 m3 in 2018 (Mekuriaw 2019). According to this research, the water consumption of the town showed an increasing trend from year to year contradicting the studied town, which indicated a mixed trend. Another research which was conducted from 2007 to 2013 and had identical size but different characteristics reported that the annual water consumption ranged between 109,651 and 151,359 m3 (Abate 2016). This research also found that the water consumption showed an increasing trend as opposed to the water consumption trend of the studied town, which was mixed. Based on the research carried out in Mekelle town which is a regional town that has larger size from that of the studied town from September 2008 to August 2009, the annual water consumption was recorded as 3,241,647 m3 (Asgedom 2014). This research suggests that the average annual water consumption is estimated at 3,256,997.43 m3, which is higher than similar towns such as Yejubie, Boditi, and the larger town of Mekele.
Non-revenue water
The NRW measurements are as follows: in 2011, it was estimated at 1,319,628.2 m3 (61.06%) and decreased to 481,353.94 m3 (22.85%) in 2012 (Figure 3). This reduction might be due to the increase of system loss control, and service management by the water supply utility of the town. It then increased significantly in 2013 to 1,966,417.57 m3 (92.95%) and decreased again in 2014 to 765,847.65 m3 (31.06%). The greatest increase of NRW in the year 2013 might be due to the reduction of system control and monitoring thery by an increase of both real and apparent losses in the system. In 2015, it was recorded as 60,466.26 m3 (1.81%). This decrease was due to the implementation of legal measures as well as strong service management. Subsequently, it gradually increased from 2016 to 2018 with values of 708,330.39 m3 (18.76%), 1,484,368.56 m3 (29.57%), and 2,817,792.41 m3 (37.13%) respectively (Figure 3). This gradual increase might be due to the increase in water supply sytem monitoring and the maintenance of water supply system components in the respective years. In 2019, there was a decrease to 2,036,209.45 m3 (25.98%), followed by an increase in 2020 to 5,095,122.92 m3 (54.42%). The reduction of NRW in 2019 was due to the implementation of an integrated water supply system control and the rehabilitation of part of the system. In 2021, the NRW was 2,769,479.74 m3 (29.33%) (Figure 3).
Over the years studied, the lowest NRW was recorded in 2015, and the highest was in 2013 (Figure 3). The results showed a decreasing trend from 2011 to 2012, an increasing trend from 2012 to 2013, a decreasing trend from 2013 to 2015, an increasing trend from 2015 to 2018, a decreasing trend from 2018 to 2019, an increasing trend from 2019 to 2020, and a decreasing trend from 2020 to 2021 (Figure 3). Overall, the NRW percentage in the town was estimated at 36.81%.
Globally, the average annual volume of NRW is estimated at 100.26 million m3, representing about 52.5% of the annual system input volume. This amount could potentially supply nearly 4 million people in urban areas, assuming a per capita consumption of 70 l/day (Josy et al. 2024). In the target town, the average annual volume of NRW, excluding the allowable limit, was 4,876,254.27 cubic meters per year. This volume would be sufficient to supply approximately 267,192 people, assuming a per capita demand of 50 l/day. Various nations, governmental and non-governmental organizations have established maximum limits for NRW in water supply systems. For example, the World Bank recommends that NRW should be less than 25%. However, in the studied years, only 2012, 2015, and 2016 met this maximum limit.
The cumulative average of estimated NRW exceeds the World Bank's recommended value. In England and Wales, NRW stands at 19% (Farok 2016). The American Water Works Association's Water Loss Control Committee recommended in 2009 that water utilities conduct annual water audits as a standard business practice (AL-Washali et al. 2018). The California Urban Water Conservation Council established a 10% benchmark for NRW (Dickinson 2005). In Indonesia, the allowable limit of water loss is 20% (Yekti et al. 2019). In Africa, 20–25% of NRW in water supply distribution systems is considered acceptable (Onyango et al. 2022). In Ethiopia's urban water systems, the allowable limit of NRW is 25%, similar to the limit suggested by the World Bank (Negese & Kebede 2023; Beker & Kansal 2024). This indicates that the NRW in the studied town exceeded the maximum limits set by the World Bank and did not meet various national and international standards, reflecting significant water loss in the town's water supply before reaching its customers.
According to Mekuriaw (2019), the NRW for Yejube town with similar characteristics was 20.38% in 2017 and 23.9% in 2018. These values are higher than the NRW for the target town in 2015 and lower than the NRW for the target town in the other studied years. Research conducted in a similar town from 2007 to 2013 showed that the total water loss varied from 32.70 to 35.80%: 2007 (34.30%), 2008 (35.0%), 2009 (35.80%), 2010 (35.10%), 2011 (33.20%), 2012 (32.70%), and 2013 (34.60%), with an average water loss of 34.4% (Abate 2016). Asgedom (2014) reported that the NRW in Mekelle town from September 2008 to August 2009 was 965,412 m3/year (22.59%) which is similar to the NRW in 2012 in the studied town and grater than in 2015. However, it is lower than the rest years of the NRW of the studied town. According to 2010 reports, the average non-revenue rate in Israel is 12.9%, 76.7 million m3 /year (Best & Non-revenue 2013). In smaller cities the picture is more severe ranging 30–40%, while in bigger cities the rates are lower than the national average. In Algeria, NRW is estimated between 40 and 50%. From 2005 to 2010 in jordan,it is varied between 43.12 and 46.30% indicating a decreasing trend from 2005 to 2009 and an increasing trend from 2009 to 2010 (Best & Non-revenue 2013).
The Dhaka water supply system experienced total system losses of 50.49, 55.54, and 49.86% in the years 2002–2003, 2003–2004, and 2004–2005, with an average water loss of 51.96% (Farok 2016). This rate is higher than the average NRW in the target town. In Vijayawada city, more than half of the water produced and supplied to the system was lost as NRW before reaching the customers, at a rate of 54% (Rajasekhar & Ramana 2018). In Mandalay city water utility, it was found that in 2015, 30,397,093 m3 of water was supplied through the pipe networks to water users, with only 16,543,104 m3 being sold as revenue water. This means that NRW accounted for 54% of the total input water volume (Yi et al. 2017). Moreover, the NRW rates in the Kedewatan zone of Gianyar Bali reached 986,884.92 m3/year (65.53%), which is higher than the result of the current study (Yekti et al. 2019). Overall, the annual average NRW value in Dangila town (36.81%) was higher than in Yejubie, Boditi, Mekele, and Israel towns, but lower than in Jordan, Mandalay, Kedewatan, and Dhaka towns.
Per capita water consumption
Trend of average per capita water consumption in Dangila town (2011–2021).
According to Abate (2016), the per capita water consumption in 2007, 2008, 2009, 2010, 2011, 2012, and 2013 was 14.3, 14.8, 14.5, 13.9, 15.7, and 14.7 l/day, respectively, consistent with most years for the studied town. The research in Yejube town showed an average per capita water consumption of 14.13 l/day in 2017 and 15.99 l/day in 2018, similar to most years of the studied town (Mekuriaw 2019). Siraj Abduro1 and Golla's report in 2020 indicated that the average per capita consumption in Adama town was 34.5 l/day, which larger than the studied town (Abduro & Sreenivasu 2020). Zewdu (2014) reported that the average daily per capita water consumption of Axum town was 12.8 l/day, similar to the target town in 2020. Another research in Mekelle, a regional town, indicated mean daily per capita water consumption during water supply interruption and piped water service availability as 11.9 and 20.46 l, respectively (Asgedom 2014). From 1990 to 2015, the minimum standard for per capita water demand in the country was 20 l/day, with only 2011 and 2015 exceeding this standard. For the rest of the years, the demand was below the standard. In the sustainable development goals applied from 2015 to 2030, the universal water supply access plan of the country set the minimum quantity of water required at 50 l/c/day for woreda towns. However, all per capita water consumption estimated during this period was below the standard. Therefore, within the studied years, the per capita water consumption of the town was below the standard, requiring additional provision of sources, continuous monitoring, service management and maintenance of the water supply system.
Water supply coverage
The water supply coverage decreased from 2011 to 2014 due to continous increase population,leading water demand incraease and then increased in 2015 due to increasing water supply (Figure 5). From 2016 to 2018, there was an increasing trend attributed to continous in water supply,water production increase. However, from 2019 to 2021, there was a decreasing trend due to rapid population growth, leading to increased water demand (Figure 5). The town's water supply coverage was estimated at 46.38%.
In a study conducted in Yejube town, the water supply coverage was estimated at 76.5% in 2017, which was nearly similar to the coverage in the studied town in 2011 (73.43%) and higher than the coverage in other years (Mekuriaw 2019). The study also found that the water supply coverage increased to 80% in 2018, surpassing the coverage in the studied town (Mekuriaw 2019). This indicates an increasing trend in water supply coverage in Yejube town, while the target town showed a decreasing trend. Another study in Boditi town from 2007 to 2013 showed service coverage ranging from 71.5 to 78.5%, nearly similar to the coverage in the target town in 2011 (73.43%) and greater than the coverage in other years in the studied town (Abate 2016). Additionally, a research study in Dilla town, which is larger than the studied town, found that water supply coverage in the years 2011, 2012, 2013, 2014, and 2015 was 30.7, 31.9, 33.5, 35.44, and 35.7%, respectively, with an increasing trend, although still lower than in any of the studied years in the target town (Debela & Muhye 2017).
The coverage of potable water supply in Oyo State, Nigeria was found to be 27.3%, which is lower than the coverage in the studied town (Solihu & Olakunle 2021). In Brazil, the state of Santa Catarina currently has 90% water supply, aiming to reach 99% coverage (Brasil 2019). According to the World Health Organization (WHO) 2021 estimation, 90% of the world's population has access to essential drinking water services, but only 65% of Sub-Saharan Africans have this access (WHO 2021). In Ethiopia, the population's access to potable water has been increasing compared to previous years, with 50% national coverage, 41% rural coverage, and 84% urban coverage in 2020 (WHO 2021). Ethiopia faces a high scarcity of drinking water, especially in rural areas (MoWEI 2019; Beker & Kansal 2024).
Various national and international documents, including the Millennium Development Goals (MDGs) and the Sustainable Development Goals (SDG), have set targets for water supply coverage (Narzetti et al. 2023). The MDG aimed to halve the proportion of people without sustainable access to safe drinking water (Satterthwaite 2016), while SDG 6 aims to ensure the availability and sustainable management of water and sanitation for all by 2030. When the results of this study were compared with the MDG water supply coverage (50%), none of the studied years met except in 2011 (73.43%) and 2012(57.45%). However, the water supply coverage in the studied town did not meet the MDG or SDG benchmarks. Despite efforts, it is projected that the town's water supply coverage will continue to fall short of the SDG target in the coming years (Sarkar 2019; Beker & Kansal 2024).
Correlation between performance indicators
The research investigated the relationship between various water supply performance indicators. The study utilized the Pearson correlation coefficient in SPSS (version 21) to analyze the data. The results revealed a strong positive correlation (r= 0.90) between water production and water consumption and a similarly strong positive correlation (r= 0.87) between water production and NRW. Both of these correlations were found to be statistically significant with p-values below the significance level (0.05) (Table 1). Conversely, negative correlations were observed between water production and per capita water consumption (r= − 0.20) and water supply coverage and water production (r= − 0.56). Both of these relationships were also statistically significant with p-values greater than the significance level (0.05) (Table 1).
Correlation between water supply performace indicators from Pearsons'correlation
. | A . | B . | C . | D . | E . | |
---|---|---|---|---|---|---|
A | Pearson Correlation | 1 | 0.902a | 0.870a | −0.20 | −0.57 |
Sig. (two-tailed) | 0.000 | 0.001 | 0.56 | 0.07 | ||
N | 11 | 11 | 11 | 11 | 11 | |
B | Pearson Correlation | 0.90a | 1 | 0.720b | 0.13 | −0.62b |
Sig. (two-tailed) | 0.00 | 0.013 | 0.70 | 0.04 | ||
N | 11 | 11 | 11 | 11 | 11 | |
C | Pearson Correlation | 0.87a | 0.72b | 1 | −0.43 | −0.45 |
Sig. (two-tailed) | 0.001 | 0.01 | 0.18 | 0.17 | ||
N | 11 | 11 | 11 | 11 | 11 | |
D | Pearson Correlation | −0.20 | 0.13 | −0.43 | 1 | 0.24 |
Sig. (two-tailed) | 0.56 | 0.70 | 0.18 | 0.48 | ||
N | 11 | 11 | 11 | 11 | 11 | |
E | Pearson Correlation | −0.57 | −0.62b | −0.45 | 0.24 | 1 |
Sig. (two-tailed) | 0.07 | 0.04 | 0.17 | 0.48 | ||
N | 11 | 11 | 11 | 11 | 11 |
. | A . | B . | C . | D . | E . | |
---|---|---|---|---|---|---|
A | Pearson Correlation | 1 | 0.902a | 0.870a | −0.20 | −0.57 |
Sig. (two-tailed) | 0.000 | 0.001 | 0.56 | 0.07 | ||
N | 11 | 11 | 11 | 11 | 11 | |
B | Pearson Correlation | 0.90a | 1 | 0.720b | 0.13 | −0.62b |
Sig. (two-tailed) | 0.00 | 0.013 | 0.70 | 0.04 | ||
N | 11 | 11 | 11 | 11 | 11 | |
C | Pearson Correlation | 0.87a | 0.72b | 1 | −0.43 | −0.45 |
Sig. (two-tailed) | 0.001 | 0.01 | 0.18 | 0.17 | ||
N | 11 | 11 | 11 | 11 | 11 | |
D | Pearson Correlation | −0.20 | 0.13 | −0.43 | 1 | 0.24 |
Sig. (two-tailed) | 0.56 | 0.70 | 0.18 | 0.48 | ||
N | 11 | 11 | 11 | 11 | 11 | |
E | Pearson Correlation | −0.57 | −0.62b | −0.45 | 0.24 | 1 |
Sig. (two-tailed) | 0.07 | 0.04 | 0.17 | 0.48 | ||
N | 11 | 11 | 11 | 11 | 11 |
aCorrelation is significant at the 0.01 level (two-tailed).
bCorrelation is significant at the 0.05 level (two-tailed).
A indicates water production, B indicates water consumption, C indicates non-revenue water, D indicates average per capita water consumption, and E indicates water supply coverage.
Additionally, a positive correlation was found between water consumption and NRW (r= 0.72) and per capita water consumption and NRW (r= 0.13). Conversely, a negative correlation was observed between water consumption and water supply coverage (r= − 0.62), NRW and per capita water consumption (r= − 0.43), and water supply coverage and NRW (r= − 0.45) (Table 1). NRW was significantly correlated with per capita water consumption and water supply coverage, with p-values of 0.18 and 0.17, respectively. Furthermore, the average per capita water consumption was positively correlated (r= 0.42) and statistically significant (p = 0.48) with water supply coverage (Table 1).
CONCLUSION
This study evaluated the performance of the existing water supply system in Dangila town over a 7-year period. It analyzed water supply system performance indicators including water production, consumption, NRW, per capita consumption, and water supply coverage. Compared with other towns, the average annual water production was higher and did not show a consistent trend over the studied years. The study estimated the annual average water consumption at 3,256,997.43 m3, which was higher than numerous towns in developing countries like Ethiopia. The analysis of NRW showed an average value of 36.81%, which was higher than many towns in developing countries such as Ethiopia and some towns in developed countries such as Israel, but lower than other some towns outside Ethiopia. Furthermore, the NRW did not meet the maximum limits set by developed countries such as England & Wales (19%), Indonesia (20%), and developing countries in Africa, which is between 20 and 25%. It also did not meet the maximum limit set by the World Bank, which is 25%.
The study also analyzed the per capita average water consumption, estimated at 15.78 l/day, which was higher than other towns in developing countries including Ethiopia, but lower than Adama town. However, it did not meet the standards set by the millennium development goal in urban areas and the sustainable development goal.The town's average water supply coverage was estimated at 46.37%, which was lower than in Yejube and Boditi towns in Ethiopia and Oyo state in Nigeria, but higher than in Dilla town in Ethiopia. The results also showed that the water supply coverage was very low when compared to developed countries like Brazil and Sanata Cateriana, as well as the world's water supply coverage, which is 90%. It is also below the water supply coverage of Sub-Saharan Africa, where the region has very low water supply coverage. In addition, the results of the water supply coverage from the target town are low when compared to the water supply coverage of Ethiopia in urban areas in 2020.
Furthermore, the water supply coverage analysis of the town revealed that the water supply system did not meet the MDG target for water aimed to halve the proportion of people without sustainable access to safe drinking water. Additionally, the result of the water supply coverage has not met the SDG, which seeks to achieve universal access to potable drinking water for all by 2030. This indicates that even though a large quantity of water was produced and distributed to the water supply system of the town, the water supply system is inefficient. Therefore, the research concluded that continuous, well-organized service management and scientific water supply system monitoring are needed. Additionally, the development of water supply sources and integrated watershed management is important to increase groundwater potential and balance the increasing water demand.
RECOMMENDATIONS
Continuous maintenance and monitoring should be implemented for the water supply system, along with sufficient experts to operate the service effectively and regularly, minimizing water loss through the system.
The town water supply service office should establish a communication channel in each district of the town Additionally, strict rules should be implemented to hold accountable those who observe water flowing out from the system whether it is on their property before entering the water meter, at their workplace, or near their residential are and remain silent about it. Furthermore, continuous training and capacity building for water supply system operators and staff are essential to reducing NRW in the system.
The water supply service office of the town must conduct regular surveys using specific performance indicators to assess the current state of the water supply system. This allows them to take immediate action on any issues that arise within the system and to compare the results with the development plans for water supply at both the national and international levels.
To enhance the efficiency of the water supply system, it is important to use scientific monitoring instruments that can detect invisible water loss. Additionally, the components of the water supply system, including the water meter, should incorporate the latest technology.
The water supply utility should explore additional sources of water to effectively enhance water supply and expand coverage. Furthermore, planning and implementing an integrated watershed management system is crucial for increasing groundwater potential and balancing the growing demand for water.
There should be overall involvement of the private sector, the public sector, the residents themselves, and non-governmental organizations to support the improvement of water provision for the residents in the town.
ACKNOWLEDGEMENTS
I would like to express my gratitude to Debre Markos University for funding this research. I am also thankful to Dangila town water supply and sewerage service office workers for their support in data collection. My sincere appreciation goes to the Dangila town water supply and sewerage service office for the willingness to provide the necessary data for this study.
AUTHOR CONTRIBUTIONS
A.A.A. made all of the contributions to the study. A.A.A. contributed to the study's conception and design, responsible for material preparation, data collection, and analysis. Also, A.A.A. wrote the first draft of the manuscript. In addition, A.A.A. carefully reviewed the final manuscript and gave the approval.
FUNDING
Debre Markos University funded this research.
DATA AVAILABILITY STATEMENT
All relevant data are included in the paper or its Supplementary Information.
CONFLICT OF INTEREST
The authors declare there is no conflict.