Infrastructure Leakage Index Research Articles

The effect of water loss on demand–supply departure of Addis Ababa, Ethiopia

Water scarcity is a critical issue affecting numerous regions, including Addis Ababa, Ethiopia. The city’s growing population and rising water consumption place significant pressure on its existing water infrastructure. This study evaluates the impact of water loss due to leakages in the distribution system on the demand–supply gap in Addis Ababa, utilizing the WB EasyCalc software for analysis. Data analysis from 2023 indicate that monthly water loss contributes to an additional unmet demand of 5 million cubic meters (MCM), emphasizing the urgent need for effective water loss reduction strategies to enhance supply reliability. Currently, the city achieves only 42% water supply coverage, with an average loss of 300 L per connection per day and approximately 25,000 L lost per kilometer of pipeline daily. Furthermore, non-revenue water (NRW) accounts for 41.8% of total production, with real losses constituting 64%. The Infrastructure Leakage Index (ILI) score of 27 underscores the critical need for targeted leakage management interventions. The significance of this research lies in its quantification of water loss and its direct correlation with unmet demand in Addis Ababa. The findings provide essential insights for policymakers and stakeholders, highlighting the necessity for improved infrastructure management and strategic interventions to bolster water supply reliability. Implementing effective leakage reduction measures could substantially mitigate water scarcity challenges, thereby supporting sustainable urban development and enhancing public health outcomes in a city where access to clean water is vital for economic and social stability.

Towards more realistic stochastic modelling of leakage in water distribution systems

ABSTRACT A new stochastic model is developed to predict leak types and sizes in water distribution systems. By linking records of actual failures in water networks with new tools for stochastic modelling, the study provides more accurate estimates of network leakage behaviour. District metered areas (DMAs) have been adopted internationally as best practice for monitoring and controlling leakage, with the infrastructure leakage index (ILI) as the main performance indicator. The leakage exponent (N1), which quantifies the relationship between leakage rate and pressure, is a key parameter in describing DMA leakage behaviour. After analysing thousands of stochastic networks for different combinations of pipe material and ILI, the study found that different pipe materials have distinct leakage exponent distributions. Iron and asbestos cement (AC) pipes display N1 values close to 0.5, polyvinyl chloride (PVC) pipes have the highest N1 values, and polyethylene (PE) lies between PVC and iron/AC. The study further showed that current guidelines linking ILI to N1 for different pipe materials depart substantially from the observed results, indicating that these guidelines may need to be updated. The study provides a tool for more realistic modelling of leakage that offers valuable insights into the behaviour of leakage in different pipe materials.

Analysis of water losses in seven small and medium-sized water distribution networks in the south region of Cameroon (Central Africa)

ABSTRACT This paper analyzes and evaluates water losses in seven small and medium-sized water supply networks (WSNs) in the south region of Cameroon in order to contribute to improving the most effective approaches to reducing water losses in Sub-Saharan Africa's WSNs. Data were obtained from the regional delegation of the Camwater in the south region of Cameroon and analyzed using a variety of indices, including the failure intensity index, the unit coefficient of water loss per kilometer, the real leakage balance index, the non-revenue water basic, and the infrastructure leakage index. Results indicate that all the WSNs analyzed achieved mixed results compared with national data and very weak results compared with international standards. This is partly due to outdated infrastructure, rapid urbanization and urban population expansion, poor operation and maintenance policies, inadequate technical skills and technology, a lack of financial discipline, and political, cultural, and social influences. The results place the cumulative volume of water losses in the seven networks studied during the 5 years at 7.3 million cubic meters, which costs the water utility about 2.4 billion FCFA (or 4.4 million USD).

Mathematical Modeling of Drinking Water Losses Management Case Study – Cairo - Egypt

Water, As A Precious natural resource, necessitates sustainable management to minimize wastage. Excessive leakage, particularly in regions confronting water scarcity such as Egypt, directly undermines environmental objectives and principles of cost recovery. Effective water management is pivotal for reducing losses and optimizing efficiency. Accurate measurement of water production and distribution is essential to identify losses and assess water utilities' performance. This data aids in pinpointing the root causes of losses, whether physical or commercial, facilitating targeted reduction strategies. Forecasting supply-demand balance is critical for planning water networks and treatment facilities. Detailed infrastructure information enables decision-makers to discern areas experiencing water shortages and those with surplus resources. Our aim is to probe the causes of water losses in Cairo's drinking water network, the capital of Egypt, and propose managerial solutions. Operational efficiency relies on minimizing labor, material, and energy costs. Water loss poses a significant operational challenge, as components of non-revenue water can significantly impact utilities' financial stability. The IWA Water Balance offers a standardized approach to water audits, facilitating a comprehensive analysis of water production, storage, and distribution. This analysis aids in quantifying the magnitude of the water loss problem and prioritizing corrective actions based on revenue and non-revenue water components. The Cairo Water Company is entrusted with producing 5.5 million cubic meters of purified drinking water per day from 11 treatment plants, serving a network spanning 13,307 kilometers and supported by 20 maintenance centers. With a focus on serving 1.1 million citizens in compliance with Egyptian regulations, our study encompasses various metrics, including billed and unbilled consumption, unauthorized usage, and metering inaccuracies, to calculate commercial losses. Additionally, we evaluate main and storage leakages, as well as service connection leakages up to the customer meter, to determine technical losses. Through a mathematical module, we compute non-revenue water (NRW) and infrastructure leakage index (ILI) metrics. Performance indicators are utilized to assess the effectiveness of water utilities in managing losses and asset maintenance. Our designed module empowers decision-makers to evaluate and enhance asset methodologies for water loss management.

The concept of estimating the risk of water losses in the water supply network

One of the methods of increasing the availability of drinking water is to reduce water losses in existing water supply systems (WSS). The need to manage water losses in WSS is highlighted in the new Directive (EU) 2020/2184 of the European Parliament and of the Council of 16 December 2020 on the Quality of Water Intended for Human Consumption. It was indicated that the main cause of water losses is underinvestment in the maintenance and renovation of network infrastructure. The new legal provisions require a risk assessment to be carried out in the water supply system, taking into account the risk of leaks. The paper presents the concept of estimating the risk of water losses in the water supply network using the three-parameter risk assessment method and risk maps. The framework of the water balance proposed by International Water Association (IWA) were also presented, including the Infrastructure Leakage Index (ILI) for assessment of the water supply system Leakage Performance Category (LPC). The analysis was carried out for a water supply system used by 200,000 inhabitants. The LPC of the system was determined based on the ILI index. Then the water supply network pipes that could potentially be a source of leaks were identified. The analysis of the risk of water losses for the examined pipes allowed to determine which pipes should be first chosen to reduce the risk of water losses, i.e. active search for leaks.

Performance evaluation of water supply distribution system: a case study of Muke Turi town, Oromia region, Ethiopia

Abstract Adequate and sustainable supply of potable water in urban areas of developing countries is often a challenge. This study assessed the performance of the water supply system in Muke Turi town, Oromia, Ethiopia. The Water Geospatial Engineering Modeling System (WaterGEMS) model was used for hydraulic analysis of the distribution network. The water losses were determined by different indicators including non-revenue water (NRW), losses per pipe connection (LPC), losses per main pipe length (LMPL), unavoidable annual real losses (UARL), and infrastructure leakage index (ILI). The water supply coverage of the town was found as 43.34%, which is considerably low. From the hydraulic analysis, the velocity of flow in 54.2% of the pipe and pressure at 60% of the nodes were found within the recommended ranges. The NRW was estimated at 37.61%, which is above the acceptable limit. Of which, the real losses are the major ones with 37.14%. Moreover, the LPC and LMPL were found to be 298 l/d and 29,709 l/km/d, respectively, which are again above the recommended limits. Based on ILI, the annual real losses were estimated to be 4.31 times the UARL. Finally, it was concluded that access to water in the town is inadequate which is exacerbated by high losses.

İçme Suyu Şebekelerinde Kayıp Kaçak Seviyesinin Belirlenmesi: Merzifon İlçesi Örneği

Bu çalışmada içme suyu şebekelerinde meydana gelen fiziki su kayıplarının su kaynağının korunmasında önemli hususlardan biri olduğu gözler önüne serilmiştir. İçme suyu talebi nüfus artışıyla birlikte her geçen gün artmaktadır. Buna karşın içilebilir su miktarı azalmakta ve içme suyu şebekelerinde suyun etkin kullanımı önemli hale gelmektedir. Su şebekesine verilen ancak kullanıcılara ulaşmayan su kayıp kaçak olarak bilinmektedir. Kayıp kaçaklar fiziki ve görünür kayıplar olarak adlandırılmaktadır. Araştırmada su kayıp kaçak seviyesinin belirlenmesi için 2020 yılına ait sisteme verilen su miktarları, boru arıza sayıları, kullanım alanlarına göre su tüketim miktarları, minimum gece debi bilgileri belediyeden temin edilmiştir. Merzifon örneğinde su kayıp kaçak seviyesinin tespiti için su dengesi oluşturularak, altyapı sızıntı indeksi tespit edilmiştir. Merzifon örneğinde 2020 yılına ait fiziki su kayıp miktarının % 44.12 olduğu tespit edilmiştir. Altyapı sızıntı indeksi (ILI) 13.6 olarak tespit edilmiştir. Su kaynağının korunması için içme suyu şebekesindeki basınç yönetimi, şebeke yenileme, aktif sızıntı kontrolü, onarım hız ve kalitesinin iyileştirilmesi çalışmaları yapılmalıdır.

Smart Water Grids and Digital Twin for the Management of System Efficiency in Water Distribution Networks

One of the main factors contributing to water scarcity is water loss in water distribution systems, which mainly arises from a lack of adequate knowledge in the design process, optimization of water availability, and poor maintenance/management of the system. Thus, from the perspective of sustainable and integrated management of water resources, it is essential to enhance system efficiency by monitoring existing system elements and enhancing network maintenance/management practices. The current study establishes a smart water grid (SWG) with a digital twin (DT) for a water infrastructure to improve monitoring, management, and system efficiency. Such a tool allows live monitoring of system components, which can analyze different scenarios and variables, such as pressures, operating devices, regulation of different valves, and head-loss factors. The current study explores a case study in which local constraints amplify significant water losses. It develops and examines the DT model’s application in the Gaula water distribution network (WDN) in Madeira Island, Portugal. The developed methodology resulted in a significant potential reduction in real water losses, which presented a huge value of 434,273 m3 (~80%) and significantly improved system efficiency. The result shows a meaningful economic benefit, with savings of about EUR 165k in water loss volume with limiting pressures above the regulatory maximum of 60 m w.c. after the district metered area (DMA) sectorization and the requalification of the network. Hence, only 40% of the total annual volume, concerning the status quo situation, is necessary to supply the demand. The infrastructure leakage index measures the existing real losses and the reduction potential, reaching a value of 21.15, much higher than the recommended value of 4, revealing the great potential for improving the system efficiency using the proposed methodology.

Penerapan Jaringan Distribusi Sistem District Meter Area (DMA) SPAM Semarang Barat dalam Optimalisasi Penurunan Kehilangan Air Ditinjau dari Aspek Teknis dan Finansial (Studi Kasus : Area Pelayanan Reservoir Manyaran 1)

Drinking water is one of basic human needs that is very important to improve the quality of human life and economic growth of a region. PDAM Tirta Moedal, Semarang City developed “SPAM Semarang Barat” 1,000 liters/sec to serve water demand in West Semarang, Ngaliyan and Tugu sub-districts. Water losses in PDAM Kota Semarang is still at 40.10%, indicating that water distribution is not optimal. DMA is a strategy in managing water loss, especially real water loss, by dividing an open water supply network into isolated zones with smaller water meter. In this study, a technical and financial study was conducted regarding the implementation of DMA in the SPAM Semarang Barat distribution specifically for the Manyaran 1 Reservoir service area . The real water loss is caused by visible or invisible leakage of distribution pipes (background leakage). The billed authorized consumption is estimated at 4,189,607 m3/year, the unbilled authorized consumption is 7,361 m3/year. Apparent water loss is estimated at 147,455 m3/year or about 2%, while real water loss is around 2,172,896 m3/year or about 34%. The Infrastructure Leakage Index or ILI for the Manyaran 1 Reservoir distribution is 49. It means that PDAM is wasting some resource, which caused losses. Epanet 2.0 shows that peak hours pressure is between 30 – 70 m, there is no pressure below 10 m. Velocity at peak hours is in the range of 0.1 – 1.0 m/s. The investment requirement for DMA development in the Manyaran 1 service area Rp. 18,786,292,828, - for development of services as much as 5,843 SR. District Meter Area in distribution system is estimated to reduce the leakage rate by up to 20%, so that the potential revenue will increase by Rp. 26,083,764,633,-. It means that DMA is one of ways to solve water leakage problem.

ANALISIS KEHILANGAN AIR (NON REVENUE WATER) PADA PERUSAHAAN DAERAH AIR MINUM (PDAM) KOTA BAU BAU

Water loss can be defined as the difference between the recorded amount of water in the system and the amount of water out of the system shown, in a water supply system is not entirely produced water installations reach consumer. Usually there is a leak here and there, called the loss of water. Then to reduce or minimize the water loss rate needed the right solution. One of solution that can be used is the Non Revenued Water (NRW) program. NRW can be defined as water that can be measured and a known amount of be chased but can not or may not be income, but it can be justified. The one of the methodologies that can be used to determine the amount (NRW) is a method of infrastructure leakage index (ILI) used Software WBEasycalc3. Water loss rate is the percentage ratio between water loss and the amount of water distributed in piped water network, while the water balance is calculated based on the amount of incoming water flow, consumption meter-Revenue, customer meter inaccuracies, water loss and physical loss. Both of two magnitudes in the ILI value is calculated by using Table Matrix Target that compiled by regulators of water service DKI Jakarta.

Predicting a water infrastructure leakage index via machine learning

In this study, the infrastructure leakage index (ILI) indicator that is preferred frequently by the water utilities with sufficient data to determine the performances of water distribution systems is modeled for the first time through the three different methodologies using different input data. In addition to the variables in the literature used for the classical ILI calculations, the age parameter is also included in the models. In the first step, the ILI values have been estimated via multiple linear regression (MLR) using water supply quantity, water accrual quantity, network length, service connection length, number of service connections, and pressure variables. Secondly, the Artificial Neural Network (ANN) approach has been applied with raw data to improve the ILI prediction performance. Finally, the data set has been standardized with the Z-Score method for increasing the learning power of the ANN models, and then the ANN predictions have been made by converting the data through the principal component analysis (PCA) method to minimize complexity by reducing the data set size. The model predictions have been evaluated via mean square error, G-value, mean absolute error, mean bias error, and adjusted-R2 model performance scale. When the model outputs obtained at the end of the study are evaluated together with the classical ILI calculations, it is seen that the successful ILI predictions with three and four variables, including the age parameter, rather than six variables, have been made through the PC-ANN method. Water utilities with insufficient physical and operational data for ILI indicator calculation can make network performance evaluations by predicting the ILI through the models suggested in this study with high accuracy in a reliable way.

Using the Infrastructure Leakage Index (ILI) indicator for effective and sustainable leakage management: importance, advantages and challenges

Using the Infrastructure Leakage Index (ILI) indicator for effective and sustainable leakage management: importance, advantages and challenges

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.

Analysis of Economic Leakage Level and Infrastructure Leakage Index Indicator by Applying Active Leakage Control

AbstractActive leakage control (ALC) has an important place in the management and prevention of leaks in water or/and gas distribution systems. However, cost–benefit components and the amount of ec...

Correlation analysis of key operating indicators of waterworks with the Infrastructure Leakage Index (ILI)

Correlation analysis of key operating indicators of waterworks with the Infrastructure Leakage Index (ILI)

Water Network Improvement Using Infrastructure Leakage Index and Geographic Information System

This study aimed at determining Infrastructure Leakage Index (ILI) supported by Geographic Information System (GIS) to facilitate strategy determination, map problems, and determine potential revenue for actions to solve leakage realistically, effectively and efficiently. Economic analysis was carried out to determine investment feasibility of corrective actions for leakage of clean water network infrastructure. More importantly, variables in this study were obtained from literature review. Primary and secondary data were then collected and analyzed statistically, and other economic analysis tools were also used. This study used a quantitative method with a population of 11 (eleven) service zones involving 35 leaders, executors and staff of leakage team. All populations of service zone were taken as research sample, while for leakage team, sample was taken using Slovin formula which obtained 32 respondents. Questionnaires were distributed to find the main affecting factors using AHP (Analytical Hierarchy Process) method with the help of Expert Choice software Results of this study indicated that there were basically five main factors causing water loss due to infrastructure leakage. Handling infrastructure leakage could reduce rate of physical water leakage by 48.5% (from 11.38% to 5.86%) of the total physical losses per year. In addition, return on investment was obtained in year 3, while profits were earned in year 4.

Su kayıp yönetimi için temel hesaplama araçlarının geliştirilmesi ve temel su kayıp bileşenlerinin analizi

Water loss management includes various methods and processes, and it is possible to ensure sustainable urban water management to use these methods. However, it is important to use the most appropriate tools and to analyze according to international literature in water and energy efficiency and sustainable water loss management. In this study, it is aimed to perform basic water loss analysis, which is the basis for systematic, planned and sustainable water loss management, and to develop analysis tools that provide more precise and accurate analysis. For this purpose, web-based, integrated "water balance", "minimum night flow" and "infrastructure leakage index" calculation tools have been developed and an application has been made for the pilot data set. It is thought that these calculation tools will provide significant contributions in the management of spills, monitoring water loss management performances, ensuring system efficiency, making leakage calculations more systematically and precisely, and making water loss management calculations in accordance with international standards.

Correlation analysis of key operating indicators of waterworks with the Infrastructure Leakage Index (ILI)

Correlation analysis of key operating indicators of waterworks with the Infrastructure Leakage Index (ILI)

Nowe wymagania w zakresie jakości usług wodociągowych dotyczące strat wody

Objective: Directive 2020 / 2184 on the quality of drinking water and the European Green Deal introduce new requirements for assessing the quality of water services and the need to reduce water leakage. The main purpose of the article is to compare the methods of determining water losses used in Poland with international standards and to determine the readiness of Polish water supply systems to implement mandatory leakage estimation standards.Research Design & Methods: The article presents a review of the literature on water loss assessment methods in Poland and abroad. Data on water losses in 11 water supply systems were presented, based on the information from the Central Statistical Office and the literature. Based on the data, a comparative analysis of selected entities was carried out.Findings: With a ranking of water utilities created, the impact of input data and the adopted calculation methodology on the position of a given entity in the ranking were analysed. The assumptions made for the calculation of the indicators and the choice of the evaluation method are shown to be important in the assessment of the entities.Implications / Recommendations: Comparing the scope of data collected at the national level and the requirements for international standards, it can be concluded that in Poland these data are not sufficient to calculate the value of the ILI (Infrastructure Leakage Index). The ILI is known in Poland, but its application is limited to the local level. The introduction of new requirements for the calculation of ILI at the national level will require the implementation of methods for collecting large amounts of data from many water utilities.Contribution: Due to the important role water utilities play, the level of infrastructure maintenance in supply systems must be constantly controlled. One of the basic indicators for assessing the condition of the water supply network is water loss. The conclusion from the article can be used by water operators to better evaluate their systems. The results of the analysis indicate the need for further research and the development of new methods of assessing water supply systems. The research contributes to the development of several scientific disciplines: environmental engineering, mining and energy management and quality studies.

Water Network-Failure Data Assessment

The water-supply system is one of the basic and most important critical infrastructures. Water supply service disruption (water quality or quantity) may have serious consequences in modern societies. Water supply service is subject to various failure modes. Failure modes are specified by their degradation mechanisms, criticality, occurrence frequency and intensity. These failure modes have a random nature that impacts on the network disruption indicators, such as disruption frequency, network downtime, network repair time and network back-to-service time, i.e., the network resilience. This paper focuses on the water leakage failure mode. The water leakage failure mode assessment considers the unavoidable annual real water losses and the infrastructure leakage index recommended by the International Water Association’s Water Loss Task Force specialist group. Probabilistic statistical modelling was implemented to assess the seasonal index, the failure rates and the expectation value of the “mean time between failures.” The assessment is based on real operational data of the network. Specific attention is paid to the sensitivity of failures to seasonal variations. The presented methodology of the analysis of the water leakage failure mode is extendable to other failure modes and can help in developing new strategies in the management of the water-supply system in normal operation and crisis situations.