Non-revenue Water Research Articles

Assessing the functionality of a water-vending kiosk network with high-frequency instrumentation in Freetown, Sierra Leone

Access to safe, reliable, and equitable water services in urban settings of low- and middle-income countries remains a critical challenge toward achieving Sustainable Development Goal 6.1, but progress has either slowed or stagnated in recent years. A pilot water kiosk network funded by the United States Millennium Challenge Corporation was implemented by the Sierra Leone Millennium Challenge Coordinating Unit into the intermittent piped water distribution network of Freetown, Sierra Leone, as a private-public partnership to improve water service provision for households without reliable piped water connections and to reduce non-revenue water. This study employs the use of high-frequency instrumentation to monitor, model, and assess the functionality of this water kiosk network over 2,947 kiosk-days. Functionality was defined via functionality levels on a daily basis through monitored stored water levels and modeled water withdrawals. The functionality levels across the kiosk network were found to be 34% operational, 30% offline, and 35% empty. Statistically significant (p<0.001) determinants of functionality were found for several predictors across the defined thresholds. Finally, modeling of water supply, water demand and withdrawal capacity, and water storage was conducted to further explain findings and provide additionally externally relevant support for kiosk operations.

REVIEW ON LEAKAGE DETECTION MODEL OF WATER DISTRIBUTION SYSTEM FOR NON-REVENUE WATER

Efficient water distribution systems are essential for ensuring global access to clean water, yet the persistent challenge of Non-Revenue Water (NRW) poses a significant threat to the sustainability of water utilities. NRW, comprising losses from leaks, unauthorized consumption, and inaccurate metering, remains a critical concern with economic and environmental implications. The escalating global demand for water highlights the urgency of addressing Non-Revenue Water, with leakage being a substantial contributor to these losses. Leakage models are pivotal tools in understanding and quantifying the factors contributing to water losses. This review consolidates current knowledge on leakage models, offering insights into their applicability in reducing Non-Revenue Water. It aims to guide water engineers, policymakers, and researchers toward effective strategies for minimizing water losses, improving system efficiency, and promoting sustainable water management practices. This paper presents a comprehensive review of leakage models within water distribution systems, focusing on their role in mitigating Non-Revenue Water.

Analysis of the factors influencing the fluctuation of non-revenue water in Luangprabang City, Laos

Abstract Non-revenue water (NRW) in Luangprabang City, Laos, has been high and fluctuating. Therefore, we aimed to analyze the factors influencing the fluctuation of NRW in two district-metered areas (DMAs). The average NRWs for 16–17 months in DMA-1 and DMA-2 were 28.92 and 43.92%, respectively, whereas the coefficients of variation of the monthly NRWs were high at 49.7 and 11.7%, respectively. Among the factors causing the fluctuation of NRW, meter inaccuracies were less than 2%, although inaccessibility to customer meters was high at 46.4 and 38.7% in DMA-1 and DMA-2, respectively. However, the meter reading intervals had little influence on billed water consumption. Using the IWA Water Balance table, the apparent loss was estimated as 2.6%, whereas the real loss (24.9%) was the main component of NRW (27.5%) in DMA-2. The monthly and 3–7-month moving averages of NRW were inversely correlated with billed water consumption, indicating that both volumetric and percentage NRWs were strongly influenced by fluctuations in billed water consumption. Network simulation verified that high inaccessibility to customer meters, particularly during the COVID-19 lockdown, caused large fluctuations in billed water consumption and NRWs. Therefore, access to customer water meters should be improved to alleviate the fluctuation of NRW.

A Review Article on Analysis and Design of Water Distribution Network for Jabalpur antonment Board Area

The provision of a reliable and efficient water distribution system is fundamental for ensuring adequate water supply to urban areas. This review article aims to analyze and evaluate the design aspects, hydraulic performance, and challenges related to the water distribution network in the Jabalpur Cantonment Board Area. The study comprehensively examines the current state of the water distribution system, evaluates its operational efficiency, and proposes recommendations for enhancing its performance and sustainability.The review commences by providing an overview of the Jabalpur Cantonment Board Area, highlighting the demographic, geographic, and infrastructural aspects relevant to the water distribution network. It delves into the existing system layout, network configuration, pumping stations, reservoirs, pipe materials, and other infrastructure components contributing to the distribution of potable water to the residents.Furthermore, the review article conducts a detailed analysis of hydraulic modeling techniques and software applications utilized in assessing the performance and optimization of the water distribution network. It scrutinizes factors influencing network efficiency, including water demand patterns, pressure management, leakage detection, and water loss reduction strategies.Through a critical evaluation of the existing challenges faced by the water distribution network in Jabalpur Cantonment, the review identifies issues such as aging infrastructure, inadequate maintenance, uneven distribution, non-revenue water, and insufficient pressure management.

Water meter inaccuracy assessment and operation control considering customer information

Water Meter Inaccuracy (WMI) is one of the apparent loss components contributing to an increase in non-revenue water. The estimation of the volume of water lost due to WMI and control within a utility is still a challenge; thus, the current study investigated its field operation using customer consumption records. A few studies estimated WMI using data obtained in a controlled experimental environment; however, WMI assessment requires a significant computation that includes unforeseen field fault operating environment. This study is of the view that experimental results are necessary for meter type selection, based on the designed flow characteristics and proposes a WMI assessment and control approach in which the field under- or over-registering meters are identified in a billing system. The analysis of this study reveals that a utility operation environment, economic factor and social trust can be efficiently improved using customers water consumption records.

Non-revenue Water Reduction

SCADA systems are essential for water management in smart cities. They provide real-time monitoring, control, early detection of issues, efficiency improvements, enhanced resilience, and data-driven decision support. By leveraging SCADA technology, water utilities can optimize operations, reduce water losses, ensure a reliable supply, and contribute to sustainable water management in smart cities. Non Revenue Water (NRW) refers to water that is produced and lost before it reaches consumers or generates revenue for water service companies (WSCs). The summary highlights the importance of reducing non-potable water as it leads to increased water availability and revenues for WSCs. This is done by installing flow meters and water pressure measuring devices on the water sources or the entrances and exits of the isolated area, then calculating the amount of water feeding the area and the amount of water accounted for, and from it the amount of non-accountable water can be calculated, and work to reduce it by detecting leakage - Detecting stealth connections and installing water meters that work efficiently. The reduction of commercial losses, which includes issues like inaccurate billing or theft, can significantly improve revenue generation. Similarly, reducing physical/real losses, such as leaks or inefficient distribution systems, allows WSCs to postpone capital investments needed for water source development. To address this issue, departments such as Network Operations, Geographic Information Systems (GIS), Hydraulic Analysis, and the commercial sector must collaborate to estimate and identify the different components contributing to NRW and water loss reduction.

Reducing non-revenue water in Luxor-Egypt using GIS

Unaccounted for Water, referring to all losses from the water system, illegal or otherwise, frequently exceeds 40% of all water produced. This represents a major strain on utility operations and budgets. A large amount of Unaccounted for Water indicates large losses in the revenue of the utilities. Deficiency in financial resources normally leads to a deficiency in the performance of the utility. This deficiency in performance may affect the operation and maintenance of treatment plants and network components. The main objective is to reduce Unaccounted for Water rates. The multi-stage systematic process involves measuring water flow, leak detection, installing and fixing meters, reducing illegal connections, and increasing billing and collections, and developing Geographic Information System layers and databases for all of them. Another objective is to connect Geographic Information System maps with Billing, hydraulic systems, hotline systems, etc. After choosing a pilot area, we review similar activities, conduct field visits, and hold meetings, prepare the timeline schedule, prepare, and implement base maps and the water network, analyze, and compare end-line results, and report the results. A high reduction in the Unaccounted for Water percentage is expected due to fixing the discovered leaks. The issue of Unaccounted for Water, encompassing losses from the system, whether legal or illegal. This places a significant burden on both utility operations and budgets. A substantial volume of Unaccounted for Water signifies considerable revenue losses for the utilities, and the financial constraints often translate into performance deficiencies within the utility. We formulated a methodology aimed at assisting utilities in lowering Unaccounted for Water rates. This structured, multi-stage process includes activities such as measuring water flow, implementing leak detection measures, installing, and repairing meters, minimizing illegal connections, and enhancing billing and collection.

Assessing the impact of corporate social responsibility spending on performance of water supply and sanitation authorities in Tanzania

This paper assesses the impact of corporate social responsibility spending on the performance of water supply and sanitation authorities in Tanzania. Revenue collection efficiency and non-revenue water were used as performance proxies. The study employed a retrospective longitudinal research design with a quantitative approach, utilizing secondary data from 114 water supply and sanitation authorities over five years (2015–2019). Both random and fixed effect estimation techniques were applied to determine the impact of CSR spending on performance. The results indicate a significant positive effect of CSR spending, notably enhancing revenue collection efficiency and reducing non-revenue water. Additionally, control variables such as organization size, age, number of employees, and customer complaints significantly impact performance. This study provides a nuanced understanding of how CSR spending in the public sector, specifically within water supply and sanitation authorities, can improve revenue collection efficiency and minimize non-revenue water. It emphasizes the importance of CSR activities in the water sector and advocates for policies promoting CSR to enhance organizational performance.

An Evaluation of the Efficiency of the Localize, Locate, and Pinpoint Strategy in Reducing Water Loss

This study aimed to assess the efficiency of the Localize, Locate, and Pinpoint (LLP) strategy in curbing water loss within a water district. Employing a descriptive-comparative research design over seven days, the study utilized secondary data sourced from the water district office. This data, collected through noise loggers, electronic ground microphones, and other equipment associated with the LLP strategy, provided insights into the water loss reduction efforts. Before implementing the LLP strategy, the water district suffered from a high water loss exceeding 30%. Following the implementation, although the water loss remained high, it showed improvement, indicating that other factors might contribute to the loss. The results demonstrated a significant disparity in water loss before and after implementing the LLP strategy, suggesting that while complete elimination of losses may not be feasible, the strategy aids in substantial reduction. The study revealed that the noise levels, used as an indicator of potential leaks, exhibited a moderate confidence level before the implementation of the strategy. Conversely, after the LLP strategy adoption, the confidence level dropped to a low, indicating a decreased likelihood of leaks. Moreover, statistical analysis confirmed a noteworthy difference in noise levels before and after the implementation, lending support to the efficacy of the LLP strategy. Furthermore, this study underscores the positive impact of the Localize, Locate, and Pinpoint strategy on water loss reduction, despite not achieving complete elimination. The findings underscore the strategy's efficiency in identifying and minimizing potential leakages, thereby contributing to the reduction of non-revenue water within the water district.

Prediction of non-revenue water ratio in water distribution systems

Prediction of non-revenue water ratio in water distribution systems

Dynamic analysis of non-revenue water in district metered areas under varying water consumption conditions owing to COVID-19

Increasing water demands and high water losses have rendered securing safe water challenging in the 21st century. Although non-revenue water (NRW), as a percentage of system input, has been commonly used by water utilities worldwide, in-depth analyses on the influence of water consumption fluctuation on NRW has never been conducted; instead, taking one-year average NRW volume has been recommended. Thus, this study analyzed the influence of water consumption fluctuation on NRW using the data of five district metered areas (DMAs) in Colombo City, Sri Lanka, and also by the network simulation analysis. The results showed that percentage and volumetric NRWs are strongly correlated with water consumption (r = 0.9373 and 0.9121, respectively) and with each other (r = 0.9977) due to pressure changes in water supply networks caused by water consumption fluctuation. Therefore, dynamic analysis of NRW by plotting DMA inflow and NRW against water consumption was conducted using the aforementioned DMA data and long-term (1956–2021) water consumption and NRW data in Tokyo. This method identified two factors influencing NRW: water consumption fluctuation and network leakage changes, and the results were verified; thus, it can be applied to NRW analysis even under the influence of high water consumption fluctuations.

Water woes: the institutional challenges in achieving SDG 6

BackgroundSustainable Development Goal (SDG) 6 envisions a future where everyone has access to clean water and sanitation. Yet, as 2030 looms closer, the complexity of achieving this target becomes apparent, with issues far surpassing basic water infrastructure and utility challenges. The underlying problems lie in broader spheres such as governance, policymaking, and financing.Main bodyThe global landscape of water management is marked by complexities that transcend the operational troubles of water utilities. Financial sustainability is a monumental task. And while it is true that water utilities struggle with revenue generation, the broader picture reveals systemic challenges. The true cost of water provision often extends to ecosystem services such as watershed protection. Often, these services are not internalized in the revenue models of utilities but are typically subsidized by governments or simply not considered. Balancing affordability for users with cost recovery for service providers, however, is not just an arithmetic exercise. It is also a question of equitable policies. Non-revenue water (NRW), resulting from physical losses such as leaks, theft, and inaccurate [or lack of] metering, exacerbates existing financial strain. Annual NRW losses are estimated at an astonishing 126 billion cubic meters, costing roughly USD 39 billion. But at the most fundamental level of achieving SDG 6 is misgovernance. Effective water governance demands consistent policies, coherent collaboration among diverse stakeholders, and comprehensive strategies that cater to specific regional contexts. Current models often suffer from fragmented policies, inadequate public-private partnerships, and weak engagement mechanisms. A glaring gap exists between academic advancements in water management and their practical implementation in policymaking. Moreover, international cooperation, while vital, reveals an unequal landscape in knowledge exchange. Knowledge transfer is often skewed, favoring dominant nations while sidelining voices from the Global South. This emphasizes the need for an inclusive, equitable, and context-specific global cooperation model.ConclusionThe road to realizing SDG 6 is multifaceted, and while on-the-ground solutions are essential, the real success lies in addressing the foundational challenges. This requires innovative financial solutions, reimagining water governance structures, and ensuring all voices, especially from the Global South, are heard and integrated into global policies. As 2030 nears, it is the synergy of governance, finance, and technology that will ultimately make clean water and sanitation a reality for all.

A Contribution to Increasing Efficiency in the Water Utility Sector—A Case Study in Kosovo

Due to the rise in energy and water consumption, especially via water losses in water supply systems, it is imperative to reduce and eliminate such problems. Nowadays, commercial efficiency problems are present throughout the world, but in countries with a lower level of development, they have a considerable presence. Therefore, Kosovo, as such a country, has serious problems regarding commercial efficiency in the water sector. Improving performance involves sharing best practices to reduce water losses and improve collection rates. Water losses in Kosovo range from 55 to 61% of water production. Besides water losses, water utilities in Kosovo also have a low collection rate, ranging from 61% to 93% of issued invoices. Alongside these levels of non-revenue water and low collection rates, only 33.55 to 56.73% of produced water generates income. Improvement may be possible through profiling the consumption of large customers, calibrating and installing water meters with high accuracy, reading water materials with handheld devices, improving pressure management, finding illegal connections, selling a proportion of old debts, replacing old pipes with modern materials, etc.

Hamilton's Proactive Leak Detection Improves Infrastructure and Water Quality

Key TakeawaysHamilton, Ont., has an older, elaborate water distribution system, with high levels of nonrevenue water (NRW).The city was determined to reduce its NRW, so it conducted a leak detection pilot study to explore advanced technologies that could improve detection efforts.With a 95.6% accuracy rate from the pilot test results, the city implemented a full‐scale, proactive leak detection program.

Pressure‐Sensing Technology Mitigates Nonrevenue Water Loss

For more than two years, Aqua Pennsylvania has used remote pressure‐sensing technology to identify pressure transients, reduce water main breaks, and mitigate nonrevenue water.

Strategi Penurunan Non Revenue Water (NRW) melalui Analisis Neraca Air dan Indikator Kinerja NRW pada Jaringan Distribusi SPAM Cabang Karawang

Perumdam Tirta Tarum as a BUMD with healthy performance and has FCR (Full Cost Recovery), but the NRW (Non Revenue Water) score is still quite high at 32.16%. The Karawang branch is the largest contributor to the volume of water loss, around 33% of the total water loss in 19 Branches/IKK units in other service areas. This study uses water balance analysis methods and NRW performance indicators to formulate recommendations for NRW reduction programs. Annual water loss during the period April 2022 to March 2023 was 23.96% with a loss volume of 2,343,756m3/12 months. The percentage of physical water loss is 18.49% and non-physical water loss is 5.47%. When converted to cost values, the annual loss of non-physical water is Rp.2,610,791,315.- and the annual loss of physical water is Rp.8,640,197,936.-. Physical loss is classified as category C performance (severe leakage) and the overall ATR performance indicator is classified as category C (poor ATR condition). Recommendations or strategies for handling NRW efficiently at study locations can be formulated after understanding the causes of NRW and the most influencing component factors.

Evaluation of Non-revenue Water Management: A Case Study of Lodwar Water Supply in Lodwar Municipality, Kenya

This paper scrutinises the availability and effectiveness of non-revenue water management practices at Lodwar Water Supply, which serves an urban populace in Arid, Northern Kenya. The case study is representative of medium-sized water utilities serving populations in water-scarce areas within developing countries. Challenges encountered by water utilities in developing countries are unique, and their resolution requires context-specific approaches. For instance, Lodwar water supply posted an estimated 52% non-revenue water in a recent assessment by Kenya’s water services regulatory agency (WaSREB). The utility lost half of its production. This is unacceptable for a water utility serving an arid service area with 43% water coverage. This paper documents the findings of a causal study conducted to identify probable reasons for the water utility performance and develop recommendations to reverse the worsening non-revenue water trend. Four aspects were identified for scrutiny at the water utility; these were: Availability of strategies, methods, and policies for non-revenue water reduction; Employee and Consumer awareness of non-revenue water management; Techniques for enumeration of components of non-revenue water and the nexus between the foregoing and the prevailing poor non-revenue water and overall performance of the water utility. Three hundred eighty-five questionnaires were administered to consumers, randomly sampled across the selected study area. This was followed by a non-quantitative audit of non-revenue water practices by the water utility and focused group discussions with top management and technical staff at the water utility. This study established the absence of deliberate strategies for control of non-revenue water by the water utility as the critical reason for the unacceptably poor non-revenue water and overall performance of Lodwar Water Supply. Recommendations for mitigation of non-revenue water included the establishment of zone-specific, updated consumer database; DMAs with functional inflow meters; acquisition of meter testing and calibration system; institution of active leakage control initiatives and personnel capacity development

Leveraging Transfer Learning in LSTM Neural Networks for Data-Efficient Burst Detection in Water Distribution Systems

Researchers and engineers employ machine learning (ML) tools to detect pipe bursts and prevent significant non-revenue water losses in water distribution systems (WDS). Nonetheless, many approaches developed so far consider a fixed number of sensors, which requires the ML model redevelopment and collection of sufficient data with the new sensor configuration for training. To overcome these issues, this study presents a novel approach based on Long Short-Term Memory neural networks (NNs) that leverages transfer learning to manage a varying number of sensors and retain good detection performance with limited training data. The proposed detection model first learns to reproduce the normal behavior of the system on a dataset obtained in burst-free conditions. The training process involves predicting flow and pressure one-time step ahead using historical data and time-related features as inputs. During testing, a post-prediction step flags potential bursts based on the comparison between the observations and model predictions using a time-varied error threshold. When adding new sensors, we implement transfer learning by replicating the weights of existing channels and then fine-tune the augmented NN. We evaluate the robustness of the methodology on simulated fire hydrant bursts and real-bursts in 10 district metered areas (DMAs) of the UK. For real bursts, we perform a sensitivity analysis to understand the impact of data resolution and error threshold on burst detection performance. The results obtained demonstrate that this ML-based methodology can achieve Precision of up to 98.1% in real-life settings and can identify bursts, even in data scarce conditions.

Topology-distance-based clustering method for water distribution network partitioning

Abstract Partitioning water distribution networks (WDNs) into district metered areas offers benefits including reduced nonrevenue water and simplified pressure management. However, current research in this field tends to narrowly focus on the topological relationships among nodes, often overlooking the influence of pressure reducing valves (PRVs) and pump stations on clustering results. To address this limitation, this study introduces a topology-distance-based clustering (TDBC) method that enhances the accuracy of partitioning by explicitly considering the impact of PRVs and pump stations. In the TDBC method, the Floyd algorithm is initially employed to construct a topological distance matrix that quantifies the degree of node connectivity. By amplifying topological distances for links including PRVs and pump stations, their effect on clustering results is incorporated. Subsequently, nodes are clustered using the K-means algorithm based on the resulting topology-distance matrix. The proposed TDBC approach is applied to four network cases, and its outcomes are compared with those of two traditional methods. The comparative analysis indicates that the TDBC algorithm achieves precise partitioning results for networks incorporating PRVs or pump stations, while ensuring a harmonious balance between modularity and the uniformity of the partitioning results, even in networks with complex structures and highly interconnected loops.

Addressing non-revenue water as a global problem and its interlinkages with sustainable development goals

Abstract By 2050, over 40% of the global population could face severe water stress. The 2030 Agenda explicitly integrates water resources, supply, and sanitation, emphasizing sustainability for present and future generations. Non-revenue water (NRW) creates a barrier to sustainability through energy, water loss, and money not collected through water bills. However, NRW is well recognized by water service providers, and a comprehensive solution is lacking. Addressing NRW is vital to sustainable operations and achieving the Sustainable Development Goals (SDGs). This desk literature review investigates NRW's links with SDGs, highlighting global and local impacts, flameworking interconnections, and revealing economic, social, and environmental consequences. The study revealed that NRW not only aligns with various SDGs, particularly SDG 6 and SDG 13, but also has synergies with other goals related to energy and sustainable consumption. Reducing NRW can achieve more sustainable and resilient water systems, and contribute to the broader SDG. The cost of NRW extends beyond the financial implications for water utilities. It also encompasses the economic impacts on industries and businesses, which impacts exceeded water productivity, increased operational costs, and economic development constraints.