Non-revenue Water Research Articles

Acoustic Monitoring Efficiently Identifies Pipeline Leaks

A Pennsylvania water utility was facing nonrevenue water loss of 20%. By implementing a remote acoustic monitoring system, the utility significantly decreased water loss, reduced costs and employee overtime, and improved customer service.

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.

Cost-effective non-revenue water reduction: analysis through pilot activities in Kigali City, Rwanda

ABSTRACT Non-revenue water (NRW) is a major problem for water utilities, and its reduction has become an important challenge in ensuring a sustainable water supply. However, a lack of clarity regarding the cost–benefit analysis of investment in pilot activities to reduce NRW may hinder further investment in such projects. Thus, we attempted to identify strategies for effective NRW reduction and establish a method for estimating their cost-effectiveness. To this end, a project to strengthen the NRW management capacity and build a sustainable NRW reduction system was implemented in Kigali City, Rwanda, between 2016 and 2021. The project included four objectives: enhancement of the planning capacity for NRW reduction; acquisition of basic knowledge, skills, and techniques for NRW control; enhancement of staff capacity to execute NRW reduction measures; and establishment of a system to accurately measure NRW ratios. The project helped to formulate a 5-year plan for NRW reduction and 596 employees of Kigali City were trained for the same. The NRW ratios were reduced by 10 and 12% in the two pilot areas of the city. Cost–benefit analysis revealed the effectiveness of the investment in NRW reduction activities over time.

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).

The role of Water Operator Partnership in accelerating adoption of new working process for non-revenue water reduction: a case study – Waterworx WOP between Perumda Air Minum Tirta Moedal and VEI

ABSTRACT This paper presents the approach, results, and contributing factors to success of a Non-Revenue Water (NRW) reduction intervention in a Water Operator Partnership (WOP) between Perumda Air Minum Tirta Moedal Kota Semarang (PDAM Semarang) and VEI Dutch Water Operators (VEI). This paper makes a case for the prioritisation of small but smart operational investment to improve the water use efficiency (SDG 6.4) in infrastructure development programmes which typically focus on expanding network coverage (SDG 6.1) alone. The successful intervention is hinged on VEI's international track record, and PDAM's commitment to performance improvement. VEI training and coaching focused on strengthening the NRW management organisation, working processes, and skills to conduct top-down assessments by quantifying NRW components with historical data, localize leaks with live flow/pressure data, and pinpoint/repair leaks through active leak detection. PDAM staff demonstrated a steep learning curve by spearheading the establishment of a dedicated NRW department and sharpening its leak detection procedures to reduce NRW levels from 39 to 26% in 5 months in pilot area. The evaluated business case revealed that the relatively small investment (USD 60.000) was recovered within 1.2 years.

Adaptation to the impacts of climate and demographic changes on water supply and demand in Nairobi, Kenya

ABSTRACT Uncertainties, due to the impacts of climate change on water resources and demographic rise, pose challenges to the decision-making process in the management of water resources for urban cities thus, adequate planning ought to incorporate uncertainties. The study objective was to develop adaptation pathways using the Climate Risk Informed Decision Analysis (CRIDA) approach to enhance the water system performance. Using the hydrological model for the Thika-Chania Sub-catchment, the prediction of future water flows for 30 years period was done. A multivariate econometric approach was used to investigate the socio-economic factors on water use and forecasts on future water demand. The demand scenarios were based on different population growth patterns corresponding to the exponential growth and decreasing rate of increase growth, with per capita consumption scenarios of 85 and 170 lpd. The system performance was evaluated through stress testing to determine the behaviour under different scenarios. The results revealed an increasing supply–demand gap due to the impacts of climate and demographic changes. Adaptation strategies and their tipping points were established leading to the development of adaptation pathways. From the assessment of the flexible adaptation pathway, it was concluded that the non-revenue water strategy be considered as a priority project by the utility.

Successes and Challenges in Nonrevenue Water Management

Successes and Challenges in Nonrevenue Water Management

Unveiling the Hidden Power of Water Services Development Plans

South African Water Services Authorities (WSAs) have been grappling with the challenge of providing sustainable water and sanitation services which is a product of the sector’s inadequate planning and practices systems. Consequently, many communities which are the end-users endure inadequate access to sustainable water and sanitation services. Thus, establishing effective planning mechanisms becomes crucial to ensure the provision of adequate and sustainable water and sanitation services, and this is the central problem of analysis and prescription for this paper. Notably, the paper recommends an already existing systems approach to local governance that takes advantage of Information and Communication Technology (ICT) to drive the modernisation of water and sanitation planning processes which are the Municipal Strategic Self-Assessment (MuSSA) and the Water Services Development Plan (WSDP). Through an emic perspective, systematic search of literature, and document analysis, this paper examines the 2022 MuSSA reports of Western Cape and Gauteng, to identify the challenges faced by the provinces. The findings reveal deficiencies in the Western Cape's investment in asset renewal, infrastructure management, reduction of non-revenue water, and adherence to national standards. Similarly, Gauteng requires comprehensive reforms to address financial instability, asset management, and regulatory compliance. The paper also examines the progress of WSDP development in the 2022-2027 cycle, specifically focusing on the 2022-2023 financial cycle to assess WSAs' compliance. Results indicate that, of 25 WSAs in the Western Cape, only 10 have initiated WSDP development, while 15 lag behind. In Gauteng, only 2 of 9 WSAs have begun the process. Notably, both provinces are behind schedule, having been expected to initiate WSDP development in 2022. The findings of this paper, give an invaluable snippet of the water services planning mechanisms at the local government to ensure proper monitoring and adequate intervention at a local level whilst ensuring the streamlining of resource allocation and recommends that the national government reflects on its shortcomings of ensuring legislative compliance by local government.

Estimating and Reducing Leakages in the Water Distribution Networks of Small Settlements: The Case of Agios Germanos in the Prespes Municipality

Pressure management is a fundamental and highly effective method for the management of real losses in water distribution networks and therefore reducing non-revenue water. In this work, a methodology is developed to assess leakages in the water distribution networks of small settlements. The settlement of Agios Germanos in the Municipality of Prespes is selected as a representative case study. The hydraulic modeling of the water distribution network in the study area is used to assess the hydraulic behavior of the existing infrastructure in its current state of operation and to find critical locations to install the necessary measuring equipment (pressure sensors, flow meters, water level sensors, and pressure reducing valves). This equipment is used to calibrate the hydraulic model, estimate leakages, and manage them effectively. Minimum night flow analysis is utilized to assess leakages in the studied network based on measurements of the hydraulic parameters from the equipment installed. The effects of pressure management on leakages are then examined by assessing the relationship between the pressure and leak flow rate in the selected settlement.

Perbandingan Algoritma Deep Q-Network dan Local Outlier Factor Untuk Deteksi Anomali Konsumsi Air Minum Pelanggan PUDAM Kabupaten Banyuwangi

Adequate provision of drinking water in quantity, quality, and continuity is needed to realize a healthy and productive society. A well-managed Drinking Water Supply System (SPAM) is essential to meet this need. Based on Government Regulation Number 122 of 2015, the implementation of SPAM involves the development and management of drinking water which is the responsibility of the local government and PUDAM as the implementer. The main challenges faced by PUDAM include the high level of water loss or Non-Revenue Water (NRW), which reaches 40% in Indonesia. One of the efforts to reduce the NRW level at PUDAM Banyuwangi Regency in the Kalipuro District area is to detect abnormal consumption in customer drinking water consumption. This study uses the Deep Q Network and Local Outlier Factor algorithms to detect anomalies in drinking water consumption, with the aim of comparing the performance of the two algorithms in identifying abnormal consumption patterns at PUDAM Banyuwangi Regency. The results of the study indicate that the Local Outlier Factor algorithm is more suitable for anomaly detection as evidenced by the absence of detection errors and an F1-Score value of 36%.

Analysis of Water Losses and the Management of Non-Revenue Water by Plateau State Water Board in Jos, Nigeria

Analysis of Water Losses and the Management of Non-Revenue Water by Plateau State Water Board in Jos, Nigeria

Quantifying the nonrevenue water problem in a sub-Saharan African environment: a practical application in the Republic of Cameroon (Central Africa)

ABSTRACT This paper aims to update nonrevenue water (NRW) estimations in Cameroon to identify challenges to reducing NRW in the country. Data were collected from the databases of the Joint Monitoring Program of WHO and UNICEF, International Benchmarking Network for Water and Sanitation, the Central Bureau of the Census and Population Studies of Cameroon, and the Demographic Health Survey. Results indicate that the global volume of NRW in Cameroon was about 84.6 million m3/year, which represents 50.8% of the system input volume. According to this estimate, it is about 32.2 billion CFA francs (USD 53.6 million), which is lost every year. By cutting down Cameroon's NRW to half its present level, about 1.75 million people could be supplied with water. This new analysis of global levels of NRW in Cameroon shows that the current estimated volume is higher than previously estimated. This is partly due to outdated infrastructure, poor operation and maintenance, over-conservative estimates used in previous estimates, and NRW level in rural areas. However, this estimate has been found to provide similar results to Camwater statistics. Nonetheless, more data would help refine the numbers.

Analyzing non-revenue water dynamics in Rwanda: leveraging machine learning predictive modeling for comprehensive insights and mitigation strategies

ABSTRACT This study investigated non-revenue water (NRW) dynamics in Rwanda from 1 July 2014 to 30 June 2023, utilizing panel data and cross-sectional datasets. It aimed to assess progress toward achieving the government's 25% NRW reduction target. Through panel data analysis and machine learning models, it examined water supply variations, NRW levels, and associated risks across fiscal years and regions. The observed average NRW of 41.24% underscores the need for targeted interventions to meet the set target. Regional disparities, exemplified by Kigali City's water network's 38.61% average NRW compared to Nyagatare's 55.31%, emphasize the importance of tailored strategies. Machine learning models indicated low and inconsistent progress across networks. Notably, no single water supply managed to meet the target in more than 20% of the 36 quarters studied. Comparison with existing literature highlighted excessive NRW in Rwanda, aligning with global trends. Achieving the 25% NRW target requires region-specific approaches, necessitating infrastructure improvements, leak detection, and capacity building. The positive correlation between water loss risk and household access to improved water sources accentuated the complexity in NRW reduction efforts. This study contributes to understanding NRW dynamics and informs sustainable water management strategies tailored to Rwanda's context.

Evaluation of ANN model for pipe status assessment in drinking water management

ABSTRACT Non-revenue water due to pipe leakages presents a significant global challenge, impacting both the economy and environmental sustainability. The current approach to pipe management for water utilities in Sweden is mainly reactive; leaks are repaired when detected, sometimes with large costs if the leakage is extensive and critical. With this study, we want to focus on proactive pipe network management by using an Artificial Neural Network (ANN) model to estimate the probability of leakage in water pipes. The ANN model was trained on leaks that occurred over 10 years. A comparison with leaks reported after the training shows that the model succeeds in identifying groups of pipes with a higher leakage frequency. Evaluation of both new and historical leaks in four different water pipe networks in Sweden showed that a higher prediction value from the ANN model was linked to a higher occurrence of leakage. This indicates that the ANN model succeeds in identifying some of the combinations of attributes that lead to leakage. An evaluation of the input attributes in the ANN model found that the most important attributes for leakage prediction were pipe material, pipe age, adjacent problems on the pipe stretch, pipe length and pipe dimension.

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.

Reducing Non-Revenue Water

Non-Revenue water (NRW) refers to water produced and lost before reaching consumers. The summary focuses on the importance of reducing Non-Revenue water (NRW), as it increases water availability and the revenues of drinking water. This reduction is achieved when we install the flow meters and water pressure devices at water sources or inlets and exits of isolated areas. We can calculate the amount of water supplied to the area, comparing it with the calculated amount and determining the volume of water not subject to accounting. To solve this, actions like leak detection to determine the location of hidden connections and installation of effective water meters. Supervisory Control and Data Access (SCADA) systems have a role in water management, providing control and real-time monitoring, early problem detection, improved efficiency, and support decision making. When we use Supervisory Control and Data Access (SCADA) technology, we can reduce water losses, ensure reliable water supplies, and contribute to city water management practices. Reducing inaccurate billing or theft can increase revenue. Also, reducing physical/real losses, like leakages or inefficient distribution systems, engage water and wastewater companies to postpone investment in water resource development. To achieve the challenge, cooperation between departments such as network operations, hydraulic analysis, and geographic information systems is required. The commercial sector is important to evaluate and identify the different components that contribute to reducing water loss (NRW).

Fiscal institutions and racial equity: Determining the price of water

AbstractMunicipal water utilities across the United States establish their own rate structures to cover operations, maintenance, depreciation, and outstanding debt repayment. Yet, little is known about how rates are determined to ensure equity and/or affordability. To identify sources of variation in residential drinking water rates, we examine municipalities in northeastern Illinois, 2015–2019. Controlling for water utility characteristics, billing structures, financial management, service quality, and demographic/socioeconomic factors, we find no statistically significant correlations between water rates and median household income or race when nonrevenue water from leaking infrastructure is considered, revealing relative racial equity in water pricing within these communities. A larger water distribution network, more water included in the base charge, and a greater number of months in the billing cycle are all associated with lower rates. Purchasing water through an individual or cooperative agreement, a greater proportion of nonrevenue water from leaking infrastructure, a higher minimum monthly base charge, and more revenue debt outstanding (while controlling for nonrevenue water) are all associated with higher rates. We also find a positive correlation between municipal sewer rates and drinking water rates that supports findings from prior research. Overall, our research aids in the development of public policy that ensures all households have access to affordable and safe drinking water to promote water equity and public health.

Innovative Machine Learning Applications in Non-Revenue Water Management: Challenges and Future Solution

The escalating global concerns surrounding Non-Revenue Water (NRW) necessitate a paradigm shift in water management strategies, and innovative machine learning (ML) applications emerge as a transformative solution. This paper investigates the intersection of ML and NRW management, recognizing the pressing need to curb water losses due to leaks, theft, and inaccuracies. As water utilities grapple with the economic and environmental repercussions of NRW, this paper explores the potential of ML algorithms, such as predictive analytics to revolutionize traditional approaches. The discussion encompasses the intricate landscape of challenges, including data quality issues, model interpretability, and the inherent complexity of implementation. Recognizing the multidisciplinary nature of these challenges, the journal emphasizes the collaborative efforts required to harmonize technological innovation with practical implementation. As the world confronts the imperative to optimize water resources, this paper posits that innovative ML applications present a pivotal opportunity to not only enhance the accuracy and efficiency of NRW management but also to foster a more sustainable and resilient water infrastructure. Through a comprehensive grasp of challenges and a proactive pursuit of remedies, stakeholders can establish sustainable, resilient, and equitable water management systems. This paper acts as a valuable reference, providing a detailed discussion encompassing Europe, China, Japan, South Korea, and specific states within Malaysia, with a specific focus on non-revenue water (NRW) systems.

Calibration of intermittent water supply systems hydraulic models under data scarcity

Abstract Intermittent water supply systems (IWSSs) are unable to meet customer demands due to water scarcity from the sources or due to economic or/and technical scarcity. Conversion to continuous water supply as a means of tackling IWSSs’ inherent problems of inequitable water distribution, limited water supply hours, high non-revenue water, system operation and maintenance costs, and poor water quality is essential for sustainable water supply. Modelling and optimisation techniques have been used to aid the conversion process, optimisation of the operation of these systems, and guiding leakage reduction actions. However, modelling IWSSs have several challenges. These include the lack of accepted existing modelling techniques that include leakage modelling and the lack of comprehensive methodology for calibrating IWSS hydraulic models under limited calibration data. This study proposes a methodology for calibrating IWSS hydraulic models that include leakage modelling. The proposed methodology involves distinct steps to mitigate the problem of data scarcity, it eliminates the trial-and-error procedure of determining the leakage emitters' coefficients by using optimisation and it presents an approach for estimating the lower and upper bounds of the emitters' coefficients. The methodology was applied to a case study in Zambia. The calibration procedure gave accurate results given the limitation of data.

Assessment of non-revenue water in the urban water distribution system network in Cameroon (Central Africa)

ABSTRACT This paper aims to assess non-revenue water (NRW) in the urban water distribution system in Cameroon. The methodological approach used in this study was based on online searches using the databases such as Google Scholar, Web of Science, PubMed, and the International Water Association. These online searches have been completed through field observations and interviews with institutional and non-institutional stakeholders in the urban water sector. Results indicate that the total volume of NRW in the urban area of Cameroon was 100.26 million m3/year, which represents 52.5% of the total system input volume. About 2 million people could be supplied by cutting Cameroon's NRW to half the present level. Findings also suggest that the water utility (Camwater) practices passive leakage control, meaning that Camwater repairs only those leaks that are visible. Reducing NRW can be achieved through leakage detection and pipe replacement, pressure management, water metering, and a program to identify, remove, and replace illegal connections.