Non-revenue Water Research Articles

Exploring the Adequacy of South African Water Law in Managing Non-revenue Water: A Focus on South African Cities

South African cities face significant levels of water wastage and inefficient use, which hamper the supply of water services to communities. A primary reason for this is high levels of non-revenue water, also known as water losses. Non-revenue water includes all water lost through physical leakages, commercial losses and unbilled authorised use before it reaches the consumer. Non-revenue water is estimated at more than thirty-seven per cent on average in South African cities, and up to sixty per cent in many irrigation and municipal supply schemes. For cities to increase their water supply and to provide sufficient water to communities, they must drastically decrease non-revenue water to reconcile water withdrawals with supply. This article critically examines the country’s water laws and policies to determine the specific duties that cities have with regard to the challenge of non-revenue water. The article also seeks to determine the adequacy of the law in managing non-revenue water in cities. While it finds that the law provides adequately for the regulation of non-revenue water in cities, many duties overlap and the legal framework is fragmented. The author offers several recommendations, including the development of improved oversight measures to ensure that cities fulfil the duties expected of them.

Assessment, Monitoring, and Reduction Strategy Development for Non- Revenue Water (NRW) of Calamba Water District (CWD), Calamba City, Laguna, Philippines

NRW is a portion of water supply that is lost and consequently, a wasted revenue for water distributor. This study develop reduction strategies of NRW in CWD through the assessment of the company’s operating practices by conducting interviews and determining the relationships between the real loss and the range of variation of pressure, and between the apparent loss and the number of service connections using simple linear regression method. Results shows that significant relationship was only shown between the number of service connections and apparent losses. Furthermore, the apparent losses came from the number of service connections is the highest contributor of water loss. Hence, the recommended reduction plans are to start and monitor the record of the age of infrastructure, to manage inaccurate meter readings, to establish a water meter repair and replacement program, and to have a regular monitoring for water theft to address the problems in NRW. Finally, it is also recommended to establish a new department that focuses in NRW reduction through standardizing zones and areas for assessment and monitoring purposes.

Performance Evaluation of Water Services Provision in Counties and Water Services Boards of Kenya

Principal component analysis has been applied to eight dimensionless water services provision parameters for forty three administrative counties and eight water services boards of Kenya, in order to group the parameters under different components based on significant correlations. Good correlation (r=0.63) exist between Water Supply coverage (C w ) and the viability of water services utilities (C omc ), while the hours of supply (H s ) is also correlated (r=0.55) to the viability of water services utilities (C omc ). Non-Revenue Water (NRW) showed negative correlation with the coverage of water supply and viability of water services utilities. In fact these two parameters showed low correlation (r<0.3) with any of the other remaining parameters. Furthermore, the similarity and dissimilarity between the counties and water services boards in terms of water services provision is evaluated. In relation to benchmark conditions, a lot of work still needs to be done to realise ideal status. Tharaka-Nithi, Uasin-Gishu, Kakamega, Bungoma, Busia, Trans-Nzoia, Meru, Garissa and Kisumu counties formed the cluster of best performing counties with a strong showing in Non-Revenue Water, viability of water services utilities, coverage of water services, Hours of supply and a weak showing in C wb i.e the ratio of cost of water billed to the average tarrif. Migori, Homa-Bay, Elgeyo-Marakwet, Vihiga, and West-Pokot counties are clustered together with a strong showing on ratio of cost of water produced to the average tariff (C wp ) and NRW but weak sewerage service coverage (C s ), Population within the service area (WSP p ) and C omc and appear to be the worst performers. Athi and Lake Victoria North Water services boards though not clustered together are the best performers while Tanathi water services board is the worst performer. Generally, utilities with weak technical performance were found to do poorly financially and also offered poor customer care and quality of service. This study therefore, is key in facilitating cross-utility comparison. Keywords: key words, water services, Principal component analysis, county, performance DOI: 10.7176/JEES/12-5-05 Publication date: May 31 st 2022

Daily Model Calibration with Water Loss Estimation and Localization Using Continuous Monitoring Data in Water Distribution Networks

Due to the increasing deployment of sensors in water distribution networks (WDNs) for continuous monitoring, hydrodynamic data are readily available for engineers to improve the daily operations of WDNs. In collaboration with Public Utility Board (PUB), Singapore’s National Water Agency, an alternative model calibration approach using continuously monitored data is proposed to facilitate PUB’s smart water grid (SWG). The generic approach was developed as an integrated solution methodology for practical engineers to conduct a series of systematic analyses daily, namely, (1) estimating the system’s daily nonrevenue water (NRW) volume and NRW time series; (2) adjusting the available pumps’ operational curves and control statuses, followed by calibrating the system’s net demand pattern to fulfill the flow balance accounting for the actual consumption; (3) identifying and rectifying possible offsets in the monitored pressure head values for each sensor station; (4) performing model calibration with anomaly localization analysis when the system’s total NRW volume exceeds its assumed background NRW volume; and (5) calibrating other physical properties to fulfill the system’s energy balance, especially for the peak demand hours. The effectiveness of our proposed approach was then tested and verified using a real-world WDN having total pipe length of >650 km with available monitoring data. Key findings from the case study analysis include (1) anomaly events localized including, but not limited to, five out of six reported leaks for the selected week to within 400 m with lead time of 1–2 days; (2) the system’s initial flow imbalance addressed by estimating the daily NRW volume and localizing the possible anomaly events; and (3) pipe roughness values calibrated to further improve the energy balance in the system, especially during the peak demand hours, by attaining an average mean absolute percentage error (MAPE) score of 2.5%.

Upaya Penurunan Kehilangan Air Menggunakan Metode Water Balance (Teknik Step Test - Sounding) dan Analisis Finansial (Studi Kasus: Graha Indah, PDAM Tirta Manggar Kota Balikpapan)

Abstract. The most common problem that occurs in the distribution of drinking water supply caused by the high rate of water loss or Non-Revenue Water (NRW), no matter how much the water loss is, it is causing a lot of disadvantages for the PDAM and has greatly affects for the company's performance. One of the efforts of PDAM Balikpapan in improving the drinking water supply system is to establish the District Meter Area (DMA) to optimize of water loss controlling. This study is located in 2 (two) District Meter Areas (DMA) namely DMA Graha Indah 1 and DMA Graha Indah 2 where the selection of study locations is based on the largest water loss rate among DMA systems in Balikpapan City. The DMA system aims to divide a wide distribution system area and hydraulically isolate the system so that it only has 1 input system. The loss of water from the results of the Balikpapan City PDAM Report 2015 for Graha Indah residence amounted to 35.44%. This research using the Water Balance Method (WB) as the main method that consists of water meter reading, step test-sounding technique, pipe repair and also using ILI as an indicator of physical loss meanwhile for non-physical loss using water meter accuracy. This study also discusses the simulation of existing network hydraulics (using the WaterCAD software V8i) as an approach to indicate water loss based on pressure along the pipeline. In attempting to reduce water loss in the Graha Indah residence, 3 scenarios in which all scenarios left 5% non-physical loss results in increased accuracy of water meter reading using an Android-based application which is an effort to reduce non-physical loss from data component error handling sub-component, then for water meter inaccuracy and illegal connection sub-component entered into the calculation in the planned scenario 100% reduction in losses non-physical water with inaccurate efforts to renew water meters and control illegal connections. Then for the remaining physical losses of 10%, 7.5% and 5% in each scenario with efforts to reduce physical water loss is to repair leaks in service pipes in both DMA. The results of research at both DMA shows that the water loss rate is quite high, namely for DMA Graha Indah 1 46.94% or 163,012 m3 (127,159 3 physical loss; 35,853 m3 non-physical loss) and DMA Graha Indah 2 is 59, 2% or 211,017 m3 (184,596 m3 physical loss; 26,420 m3 non-physical loss). The results obtained after the pipe repair has decreased as much as 4% for DMA Graha Indah 1 and 41.16% for DMA Graha Indah 2. The selected scenario is based on financial feasibility with a 5-year analysis period (i = 4.98%). The results of financial feasibility proves that scenario 3 is a selected scenario for DMA Graha Indah 1 which NPV, BCR, and BEP values ​​respectively Rp. 9,430,810,135; 3.3295; 0.1086 and for DMA Graha Indah 2 the chosen scenario is scenario 3 which NPV, BCR, and BEP values respectively Rp 8,417,476,299; 2.767; 0.146. Keywords: Water loss, DMA, WB Method, Step test, Sounding, Simulation, Financial feasibility

The Performance of the Tirta Mangutama Clean Water Public Company Badung, Bali, Indonesia

This study aims to analyze the performance of the Tirta Mangutama Regional Public Water Company in terms of the relationship between the addition of workers to maximize profit and the impact of the Covid-19 pandemic. This study was designed with concurrent embedded research, with a quantitative approach, and validated qualitatively. The results of the study found that there was no positive relationship between the addition of workers with maximum profit and the impact of the Covid-19 pandemic was found to be negative on the company’s performance in 2020. In the Tri Wulan II performance report it was found that the company’s condition was healthy (score 3.32), but some aspects, such as return on equity of 0.49 percent, operating expense ratio of 0.98 percent, customer growth of 0.27 percent, domestic water consumption is less than 20 m3/month, non-revenue water 42.61 percent, water meter turnover is less than 5 percent, and the ratio of education and training costs for human resources is in the 2.5 percent category, meaningless good. Based on the results of the study, it is recommended that the Regional Water Company Tirta Mangutama pay more attention to the low score following the provisions of the Ministry of Public Works and Public Housing.

Feasibility Analysis of Energy Recovery Using PATs in Water Distribution Networks

Power generation is becoming an increasing problem in South Africa. South Africa produces approximately 90% of its electricity from coal-fired power stations and only 5% from hydroelectric power stations and pumped storage. Durban has a very steep topography, which results in high pressure in certain parts of the water distribution network (WDN). Leakage is costly and contributes to a large extent to non-revenue water (NRW) in the network. Pressure reducing valves (PRVs) are used in WDNs to control the pressure in the pipework to reduce leakage. This excess pressure can be used to generate electricity by a pump acting as a turbine (PAT). The electricity generated is a function of the flow rate and the pressure reduction through the PAT. The hydraulic modelling software EPANET 2.2 is used for the analysis of the Cornubia Integrated Human Settlement Development Phase 2A WDN in Durban. EPANET is used to determine the strategic placement of PATs in the WDN and their setting and configuration to extract the most energy and reduce pressure in the system. A configuration of five PATs of different sizes extracts a total power output of 166.31 kW and reduces leakage in the WDN by 45.59 kL per month, which is an 18.16% reduction in leakage.

Reducing Water Loss Based on Water Balance Method (By Using Step Test - Sounding Technique) and Financial Analysis (Case Study: Graha Indah Residence, PDAM Tirta Manggar In Balikpapan City)

Abstract. The most common problem that occurs in the distribution of drinking water supply caused by the high rate of water loss or Non-Revenue Water (NRW), no matter how much the water loss is, it is causing a lot of disadvantages for the PDAM and has greatly affects for the company's performance. One of the efforts of PDAM Balikpapan in improving the drinking water supply system is to establish the District Meter Area (DMA) to optimize of water loss controlling. This study is located in 2 (two) District Meter Areas (DMA) namely DMA Graha Indah 1 and DMA Graha Indah 2 where the selection of study locations is based on the largest water loss rate among DMA systems in Balikpapan City. The DMA system aims to divide a wide distribution system area and hydraulically isolate the system so that it only has 1 input system. The loss of water from the results of the Balikpapan City PDAM Report 2015 for Graha Indah residence amounted to 35.44%. This research using the Water Balance Method (WB) as the main method that consists of water meter reading, step test-sounding technique, pipe repair and also using ILI as an indicator of physical loss meanwhile for non-physical loss using water meter accuracy. This study also discusses the simulation of existing network hydraulics (using the WaterCAD software V8i) as an approach to indicate water loss based on pressure along the pipeline. In attempting to reduce water loss in the Graha Indah residence, 3 scenarios in which all scenarios left 5% non-physical loss results in increased accuracy of water meter reading using an Android-based application which is an effort to reduce non-physical loss from data component error handling sub-component, then for water meter inaccuracy and illegal connection sub-component entered into the calculation in the planned scenario 100% reduction in losses non-physical water with inaccurate efforts to renew water meters and control illegal connections. Then for the remaining physical losses of 10%, 7.5% and 5% in each scenario with efforts to reduce physical water loss is to repair leaks in service pipes in both DMA. The results of research at both DMA shows that the water loss rate is quite high, namely for DMA Graha Indah 1 46.94% or 163,012 m3 (127,159 3 physical loss; 35,853 m3 non-physical loss) and DMA Graha Indah 2 is 59, 2% or 211,017 m3 (184,596 m3 physical loss; 26,420 m3 non-physical loss). The results obtained after the pipe repair has decreased as much as 4% for DMA Graha Indah 1 and 41.16% for DMA Graha Indah 2. The selected scenario is based on financial feasibility with a 5-year analysis period (i = 4.98%). The results of financial feasibility proves that scenario 3 is a selected scenario for DMA Graha Indah 1 which NPV, BCR, and BEP values respectively Rp. 9,430,810,135; 3.3295; 0.1086 and for DMA Graha Indah 2 the chosen scenario is scenario 3 which NPV, BCR, and BEP values respectively Rp 8,417,476,299; 2.767; 0.146. Keywords: Water loss, DMA, WB Method, Step test, Sounding, Simulation, Financial feasibility

Sustainable management of water utility in Samoa through services improvement with Okinawa Water Bureaus

This study examines how Samoa improved the capacity of Samoa Water Authority (SWA) by implementing integrated cooperation with water utilities in Okinawa Prefecture, and hardware and software development to reduce the high non-revenue water (NRW) ratio and improve water supply quality and inadequate water pressure. Standard operation procedures were formulated to enhance the capacity of SWA. The cooperation method adopted continuous on-the-job training with a bottom-up approach. Consequently, the NRW ratio was reduced from 68 per cent to 36 per cent and water supply with proper pressure was achieved in the targeted area. The quality of the tap water, in which many coliform bacteria were detected before the cooperation, achieved 100 per cent compliance with standards. The cooperation evidenced that improving water services can help users’ understanding of tariff payments, although the water tariff increased for most consumers due to a shift from fixed to metered tariff.

Water Loss Detection System of Malang Water Supply System

The implementation of the Drinking Water Supply System by PDAM is responsible for providing drinking water services to the community. Losses incurred due to water loss include being unable to meet drinking water needs, reduced revenues, increased operational costs and worsening infrastructure. One of the concrete efforts of PDAM management is to control the level of water loss. Water loss is defined as the difference between production volume and collectible water volume based on customer meter. Data analysis for water loss control is done by identifying the existing PDAM conditions related to Non Revenue Water (NRW) level issues and efforts that have been made to address them. Identification of PDAM existing conditions begins with identifying the service area as a whole through an existing network map. Then the identification of existing conditions of PDAM through existing water balance data. Water balance data is available for each component of the water balance so that existing conditions are obtained for each existing component for both commercial water loss, physical water loss, and NRW level. Asset management and technology can also play a role in water loss control analysis. Currently the use of SCADA technology in water loss control is able to monitor, control, and acquire data on a particular process continuously.

Partitioning non-revenue water for Juru Rural Service Centre, Goromonzi District, Zimbabwe

Most water supply utilities in developing countries are faced with challenges of high Non- Revenue Water (NRW). Juru Service Centre water supply system is owned and operated by the Zimbabwe National Water Authority (ZINWA). The study analysed NRW trends from 2012 to 2020 and partitioned NRW according to the IWA Water Balance. Historical data on water production and consumption maintained by ZINWA was used to assess NRW trends. Flow measurement by loggers was used to determine real losses through Minimum Night Flows (MNF) analysis. To assess the impact of meter errors and billing anomalies, meters were tested on a meter testing bench and field meter readings were carried out. Based on historical data, NRW ranges from 7.1% to 35% and an average of 16% for the period January 2012 to May 2020. However, based on primary data collected during the study period in 2020, the NRW was much higher ranging from 31% to 42% and averaged 36%. Real losses were estimated at 83% of NRW and apparent losses were 17%. Leakage on transmission and distribution mains, and service connections contributed 47% and 53% respectively. It was concluded that the main contributing factor to NRW was the real losses. The study also established that the key driver for apparent losses was unauthorised consumption which contributed to 82.5% of Total Apparent Losses (TAPL). Active leak detection and repair along with investigation of illegal consumption is recommended.

Development of scenarios for evaluating conversion from intermittent to continuous water supply strategies’ sustainability implications

ABSTRACT Planning the conversion from intermittent to continuous water supply (CWS) is rife with uncertainties. Although scenarios can be used to incorporate uncertainties in planning processes, their development and application to intermittent water supply systems are uncommon. Using drivers of water demand in water supply systems, this study developed four scenarios (business-as-usual, consumption demand management, non-revenue water (NRW) management, and holistic) for water supply systems. The scenarios were applied to the Lusaka water supply network in Zambia. The results showed that the NRW management scenario, which used the projections in the water supply investment master plan for Lusaka, is unsustainable because of insufficient water as the 15% NRW target is practically unattainable by 2035. The holistic scenario is the most sustainable, but the commitment to ensure its occurrence in Zambia is currently lacking. Possibly, donors’ directives can instil the commitment needed to attain the holistic scenario and the conversion to CWS.

Assessing Groundwater Level Declination in Dhaka City and Identifying Adaptation Options for Sustainable Water Supply

Dhaka city, having a population of about 18 million, depends heavily on groundwater as a source of quality water. However, the city is encountering a rapid depletion of groundwater, and its groundwater-based water supply is at risk of failure. This study was carried out to analyze the groundwater depletion scenarios occurring from 1970 to 2019 in the city and to find suitable options to sustain its water supply. The trends in groundwater levels (GWLs) were quantified by the non-parametric Sen’s slope and their significances were assessed by the modified Mann-Kendall test. Contour maps of GWL were generated to develop the contemporary GWL scenario in the city. Key informant interviews (KIIs) with the Dhaka Water Supply and Sewerage Authority (DWASA) officials, groundwater experts and researchers, in addition to semi-structured interviews with the DWASA consumers were conducted to assess current adaptation practices and to develop potential adaptation options. The effectiveness of the options was assessed by strengths, weaknesses, opportunities and threats (SWOT) analysis and the options were ranked through a normalization process of the weights given by the KIIs for future adaptabilities. The GWLs were found to be decreasing all over the city, varying from 0.6–2.4 m/year. The contour maps demonstrated that the groundwater of the central area had depleted more than the peripheral areas. The locations vulnerable to severe groundwater depletion were identified to be the Khilgaon, Sobujbagh, Motijheel, Dhanmondi, and Sutrapur areas and some parts of the Cantonment and Mirpur areas. Potential options identified were adopting more surface water treatment plants, rainwater harvesting, implementing a block tariff system, reducing non-revenue water, metering water consumption, and promoting public awareness. Spatially-varying adaptation strategies were also suggested for different zones. Some measures adopted by DWASA were not supported by the respondents.

Understanding the determinants of public non-revenue water reduction intention in Selangor

Malaysia's high level of non-revenue water (NRW) has reduced the ability of the water service providers to accommodate increasing water demands and caused immense financial stress for their water-related infrastructure investment as well as operating expenditures. The main purpose of this work was to examine consumer behaviour towards NRW reduction based on an extended model that integrated the constructs of the theory of planned behaviour, environmental knowledge, environmental concern and the mediator of service performance. The proposed model was examined using a self-structured questionnaire and face-to-face interviews with a targeted sample of 400 citizens currently living in the state of Selangor, Malaysia, with the method of quota sampling. The research findings identified that the factors of attitude, subjective norm, perceived behavioural control and environmental knowledge had significant influences on NRW reduction intention. In addition, it was found that the construct of service performance had a partial mediation effect in the relationship between perceived behavioural control and behavioural intention towards NRW reduction. The findings of this study could assist water-related stakeholders to develop contemporary and effective NRW reduction strategies.

Overcoming Water Scarcity With Dynamic Water Flow Rate Control (DWFRC)

South Africa (SA) being a high water stressed country, the demand is expected to grow by 17% in 2030. Beside these problems, over 37% of water in the urban piped system leaks out or is used illegally. This compounded effect pose as a serious threat to the future of the SA country as a whole. In view to partly mitigate to this alarming consternation, this work presents a Dynamic Water Flow Rate Control (DWFRC) model which could be used to alleviate the water scarcity problem faced by the world. Using SA context and standards, an investigation is first performed to understand the current water reticulation system. Thereafter, the excessive pressure problem is identified and a DWFRC solution model is provided. The model is implemented in MATLAB and simulation result demonstrated the ability of the model to conquer excessive water pressure at all time thereby ensuring long lasting water reticulation system. Not only will the this work helps fight water scarcity and combat non-revenue water problem, it will additionally help achieve efficient use of water management and storage.

Non-Revenue Water Performance: Insights from State-Led and Community-Based Water Management Regimes in Ghana

Non-Revenue Water Performance: Insights from State-Led and Community-Based Water Management Regimes in Ghana

Review on Conservation of Water by Water Audit

Water is used almost in every sector, growth in population and increase in the standard of living of people so demand is increased. Water is used by all the living creatures found in the world but a very small portion of water is available for drinking and other purposes. This available usable water is mismanaged by human beings, for this mismanagement of water introducing a tool by IWA/AWWA is water-audit. Water-audit is used for reducing water-losses, leakages and gives the information of water used by consumers. Environment audit carried out in stages, water audit also consists of many stages. In this review paper, case studies are highlighted, which gives the general methodology adopted for auditing. Water balance sheet is very useful for understanding the types of losses and type of water used in particular DMA (District Metered Area). Due to the loss of water Non-revenue water is increased, for reducing losses requires huge investments.

Water Distribution and Non-Revenue Water Management Scenario in Asian countries: Malaysian Perspective

It is being estimated by the World Bank that the operations and maintenance cost for the basic water and sanitation services (WASH) is expected to increase from 4 to 30 Billion USD per year by 2030 which substantially surpass the capital cost of basic WASH services. Still the local and global funding prioritize the capital investment in the current water infrastructure resulting in the lack or no funding for the operation and maintenance mandates especially in the developing countries of Asia due to insufficient revenue generated from consumers to cover the operational and maintenance costs. This has subsequently caused an adverse impact on the financial utility and services rendered to consumers. Many water utilities are facing difficulties with high amount of Non-Revenue Water (NRW) for the past few years. Water utilities are being forced to consider implementing an efficient NRW reduction strategy due to the rapid population growth and industrialization raise the water demand and put pressure on the water resources. Public water utilities are expected to apprehend the demand by increasing the capacity. On the other hand, to solve the increasing water demand it is not enough to just increase the capacity and production. Combine both Non-Revenue Water and the increasing of capacity is more efficient rather than a single approach plan. In Malaysia, there is 35% of non-revenue water loss and mostly are caused by pipe leakages and breakage. This paper aims to assess the NRW reduction strategies by analysing the factors affecting, and challenges faced by Malaysian water utilities in reducing NRW rates. This paper also evaluates the public perception on Non-Revenue water management to establish a way to develop public participation in Non-Revenue Water reduction program. Finding shows that public participation in Non-Revenue Water reduction management in Malaysia remains lacking as many respondents indicate a lack of knowledge and awareness in non-revenue water. Participation from the community to achieve a sustainable water source management is important to enhance Malaysia’s water safety. The paper will provide an insight to the water distribution in the Southeast Asian countries and will especially emphasize on the crisis of non-revenue water its implications and possible measures and strategies to improve the situation.

Estimating Opportunity Cost as A Tool to Evaluate Water Loss Management of Non-Revenue Water at PDAM Tirta Khatulistiwa

Water loss or Non-Revenue Water (NRW) is a national problem PDAMs, including PDAM Tirta Khatulistiwa. In fact, with a high level of water loss, there is a significant potential loss of income. This study aims to implement opportunity cost calculation as a managerial tool for PDAM Tirta Khatulistiwa in making investment decisions to improve water loss management. This research was conducted by collecting information from financial, managerial, and local government equity participation reports. Then the data reduction is carried out and calculated based on the gross margin, net profit margin, and the opportunity cost. This study indicates that the capital investment provided by the Pontianak City’s government has increased, followed by an increase in the number of consumers. However, it was not followed by an increase in the company’s profit. This is due to the opportunity cost or lost income during the business process amounting to Rp31,218,673,384.64 in 2019 with a potential income to Rp222,663,258,365.00 if it manages to suppress distribution leakage to the level of 20%. This potential income is worthy of consideration for PDAM Tirta Khatulistiwa to start water loss management in the NRW reduction program.

Average Operating Pressure Effect on Water Supply Systems Performances. A Case Study for 12 Romanian Small Water Distribution Networks

Abstract The performance evaluation of an implemented water distribution network is in tight relation with the choice of adequate measures for water loss reduction. Hence, the consequences of placing the water network in a wrong performance category are bad and will conduct to unreasonably costs or considerable water loss volumes. Therefore, the evaluation of the water network performance level based on both Non-Revenue Water (NRW) and Infrastructure Leakage Index (ILI) indicators is to be recommended. This paper deals with the performance evaluation of water distribution systems based on the calculated performance indicators NRW and ILI. For this purpose, collected data for a period of one year from 12 Romanian small water distribution systems and two simplified average pressure determination methods were used.