Urban Water Management Research Articles

Youth Engagement in Water Quality Monitoring: Uncovering Ecosystem Benefits and Challenges

A youth-centric participatory mapping approach was employed to monitor the lower Mill Creek, an urban waterway located in Cincinnati, Ohio, by collecting geospatial data points on surface water quality and ecological assets. Utilizing the ArcGIS Field Maps application, a digital survey-based tool was developed to identify key areas related to ecological assets and urban water management challenges. The purpose of this citizen science approach was to allow researchers to capture and understand community perspectives and insights while engaging in scientific research that focuses on identifying geographic vulnerability areas and ecological assets. The primary objective was to empower local community groups and residents in an environmental justice neighborhood to understand the current opportunities and constraints of the adjacent waterbody, enabling informed decision-making for future planning initiatives that benefit both conservation and remediation efforts aligned with local values and needs. A youth-centric participatory mapping approach was employed to monitor the lower Mill Creek, an urban waterway in Cincinnati, Ohio, through the collection of geospatial data on surface water quality and ecological assets. The findings, based on hotspot analysis, revealed significant spatial clustering of heavy debris near the barrier dam and the lower portion of Mill Creek, where it converges with the Ohio River. This accumulation is attributed to the structural features of the barrier dam’s inner flood catchment area, which traps debris during rainfall events. Although no areas showed spatial significance for perceived ecological services, students identified specific areas with esthetic and biodiversity value, particularly at Mill Creek’s confluence with the Ohio River and along the northern stretch of the stream corridor. These findings provide valuable insights for guiding future conservation and remediation efforts that reflect both community values and environmental priorities.

Technological innovation for urban water and rainfall extreme disaster risk management

En este trabajo se presenta una aplicación práctica del uso de las tecnologías de la información y comunicación (TIC) en la gestión de riesgos de desastres debidos a precipitaciones extremas en regiones urbanas. El objetivo es plantear, a partir del caso de estudio del deslizamiento del cerro del Chiquihuite, una de las formas en las que se puede aprovechar la información del Observatorio Hidrológico del Instituto de Ingeniería de la Universidad Nacional Autónoma de México (OH-IIUNAM) para mejorar la gestión de desastres generadas por precipitaciones extremas. En el caso de estudio, se utilizan los datos del OH-IIUNAM para el análisis temporal y espacial de las tormentas que se presentaron en la Zona Metropolitana del Valle de México entre el 1 y 9 de septiembre de 2021; también se considera el sismo que ocurrió el 7 de septiembre del mismo año. La conjunción de ambos fenómenos produjo un deslizamiento del cerro el 10 de septiembre de 2021, que provocó grandes daños en las viviendas y pérdidas humanas. En el análisis temporal realizado se encontró que las tormentas más importantes ocurrieron entre los días 1 y 8 de septiembre, destacando las tormentas de los días 6 y 7 en intensidad y precipitación acumulada. En cuanto al análisis espacial, se utilizó la interpolación IDW (interpolación de distancia inversa ponderada) para estimar la precipitación en toda la Ciudad de México (CDMX) en el periodo del 1 al 9 de septiembre, encontrándose que la zona del cerro del Chiquihuite fue una de las áreas donde cayó mayor cantidad de agua de lluvia.

Integrated urban wastewater management through on-site generation and application of ferrous carbonate

Integrated urban water management is an increasingly popular concept that cost-effectively maximizes system-wide performance by holistically considering all aspects of water and wastewater sectors. An innovative technology enabling production of high-quality bioenergy and an iron salt, ferrous carbonate (FeCO3), represents a significant opportunity for integrated urban water management. This study experimentally evaluates the effect of in-sewer FeCO3 dosing on the performance of sewers and the downstream wastewater treatment plants. Two continuous-flow laboratory-scale urban wastewater systems, each consisting of sewer reactors, a sequencing batch wastewater treatment reactor, and an anaerobic digester, were operated in parallel. After establishing comparable performance, one served as the control without any chemical dosing, while the other received a dosing of 10mgFe/L of FeCO3 in its sewer reactors. Compared to the control, the FeCO3-dosed experimental system reduced dissolved sulfide concentrations by 32.2±3.3% (at 0.58±0.05mgS/mgFe, or 1.0molFe/molS) in sewer reactors, decreased phosphate concentrations by 38.3%±3.2% (at 0.37±0.04mgP/mgFe, or 1.5molFe/molP) in sequencing batch reactors, and lowered dissolved sulfide concentrations by 72.0±4.2% (18.9±2.4mgS/L) in the anaerobic sludge digester. Iron accumulated in the sludge and improved sludge settleability by 33.9±5.5% and enhanced dewaterability of anaerobically digested sludge by 15.9±2.0%. The findings indicate multiple benefits from the integrated use of FeCO3, potentially being as a substitute for the currently used iron salts in urban wastewater systems.

Water Volume and 3D Topographic Analysis of Hub Dam, Karachi, Using Remote Sensing and Global Bathymetry Data

Background: Karachi one of the largest and fastest-growing cities in the world, the city faces severe water scarcity and aggravated by climate change, excessive groundwater extraction in dense urban areas and inefficient water distribution systems. The Hub Dam, along with the Keenjhar Lake, is the source of water for Karachi's population as well as for the industrial and urban agricultural sectors. It is therefore important to have current information on the dam's storage capacity, its topographic features and the hydrological dynamics of its catchment area, which remains poorly understood to date. Objectives: This study's primary objectives are (1) to assess the hydrography of Hub Dam using global bathymetric and remote sensing data and (2) to create a detailed 3D model of the dam to facilitate analysis of its hydrological features. (3) Also generate data-driven insights to guide improvements in Karachi’s urban water management policies. Methods: The methodology integrates global bathymetric data with remote sensing and Google Earth Engine (GEE) for analysing Hub Dam’s hydrological and topographic characteristics. Data processing and visualization were conducted in Google Colab by python codes. This process enabling an efficient workflow for handling and analysing large datasets. Results: Hub Dam 3D model is developed. The approaches is enhancing visualization of the dam's water volume and terrain features to support detailed hydrological analysis. 3D volumetric analysis estimates with total water volume at approximately 79.954 · 106 m3. It was found that currently, the Hub Dam reservoir has enough water to fulfil Karachi needs for 503 days, a critical reserve for urban planning, resource management. Using a topographic analysis that includes surrounding slopes and watershed features, key elements affecting dam performance were identified. This result helps to adjust the filling of the dam with water. The Hub Dam's ability to store water was confirmed through a preliminary volume assessment. Conclusion: The study successfully achieved its objectives. The results obtained highlight the importance of adaptive well informed strategies for sustaining well managed water resources in response to environmental pressures. The current study further advance rational water management by integrating remote sensing and data-driven methodologies into this area of knowledge. That is, the effectiveness of Using Remote Sensing and Global Bathymetry Data has been repeatedly proven by other studies in different areas of knowledge. However, in the current study, this scientific approach has successfully demonstrated the efficient and rapid acquisition of accurate, up-to-date information on reservoir capacity and hydrological characteristics, which opens up new opportunities for efficient water management.

Assessing the water metabolism of coastal urban areas based on the water mass balance framework across time periods: A case study of Cape Town, South Africa

The status of water resources in many coastal cities has become increasingly fragile. In a changing climate, the amount and intensity of rainfall have continued to decline, causing some coastal regions to experience severe drought and deteriorated water supply situation. This article presents a comprehensive study of the urban water metabolism of Cape Town, South Africa. A water mass balance framework was utilized to examine the city's water system across four distinct periods. In addition, the water-energy nexus before and after the drought crisis was evaluated. The key findings include a large amount of surface runoff in the Cape Town area that was not utilized before the drought crisis, resulting in a natural loss potential of water supply that is 2.54 times greater than water used for supply systems. During the drought, per capita water consumption dropped by a substantial 25%; at the same time, the total rate of water loss experienced a substantial decrease of approximately 21%. Since the pandemic, Cape Town's water resources policy has shifted to diversifying water sources, and the use of wastewater and natural water losses will be optimized by more than 32% in 2040 to achieve a water-sensitive city. Future research should explore the temporal and spatial dynamics of urban water flows, the impact of socioeconomic factors, and the integration of water system optimization models for enhanced urban water management.

The Application of Rain Gardens in Urban Environments: A Bibliometric Review

The increasing challenges of urbanization and climate change have driven the need for innovative stormwater management solutions. Rain gardens, as a nature-based solution (NBS), have emerged as a critical component in urban water management, particularly in enhancing hydrological regulation, water quality, and ecosystem services. This bibliometric review examines the application of rain gardens in urban environments, focusing on their roles in stormwater management, pollutant removal, and ecological enhancement. Data from 728 academic papers published between 2000 and 2023 were analyzed using the Web of Science (WoS) Core Collection, employing bibliometric tools such as the “Bibliometrix” R package and CiteSpace. The analysis highlights the increasing global interest in rain gardens, particularly since 2015, with China and the United States leading research efforts. Key findings reveal that rain gardens significantly reduce runoff, improve water quality, and contribute to urban biodiversity. In addition, their integration into public spaces offers landscape esthetics and social benefits, enhancing the quality of life in urban areas. However, challenges remain in optimizing their design for diverse climates and long-term performance. The study underscores the need for further research on plant–soil interactions, pollutant removal mechanisms, and the broader ecological and social contributions of rain gardens. This review provides insights into the evolution of rain garden research and identifies future directions for advancing sustainable urban stormwater management.

Exploring public attitudes toward implementing green infrastructure for sponge city stormwater management

Sponge city stormwater management (SCSM) strategy in China aims for sustainable stormwater handling. While many studies have examined the technical aspects of sponge city green infrastructure (SCGI), few have explored public perspectives. This study sought to understand public perceptions, the perceived value of SCGI’s ecosystem service benefits, and the potential for diverse financial compensation methods in sponge city construction. A survey conducted in five Northeastern Chinese cities, involving 1,534 participants, was analyzed using descriptive statistics and logistic regression. The findings reveal no significant correlation between socio-demographic factors and understanding of stormwater management, indicating the concept’s broad accessibility. Public valuation of ecosystem services showed clear priorities, and factors like homeownership and flood experiences significantly impacted the valuation of specific services. Moreover, the study identified a generally positive public attitude towards investing in SCSM, particularly through stormwater fees, underscoring the viability of diverse funding mechanisms. These insights are pivotal for policymakers and urban planners in formulating sustainable and resilient urban water management strategies.

Local and catchment-scale effects of water retention measures at Lake Velence

AbstractClimate change manifested its adverse impacts last year, with an extreme drought leading to a drastically low water level in Lake Velence, Hungary. Nature-based solutions have the potential to alleviate these impacts locally. While a few initiatives have been implemented in Hungary, widespread adoption of these solutions is expected to be a goal for the more distant future.This research focuses on one catchment at Lake Velence to evaluate decision-maker's readiness and urban water management infrastructure for broadly implementing nature-based solutions. Methods include delineating the stormwater system and creating a numerical model to evaluate rainfall-runoff processes and the possible impacts of nature-based retentions. Surveys among local mayors were conducted to assess their perception of existing water infrastructures and implementations of nature-based solutions. Its widespread use may become significant, but its effect on the lake's water level remains negligible.

Collaborative water governance model for potable urban water supply in Riau Province, Indonesia

ABSTRACT The literature suggests that collaborative governance is a promising framework for addressing complex public problems while some cases have also marked failure in its implementation. Furthermore, the complexities and factors of the collaborative governance context must be understood at the early stage, as they may affect its sustainability. Therefore, this study aims to understand ‘what works and what doesn't’ and the need for sustainability of urban potable water management in Dumai City, Rokan Hilir Regency, and Bengkalis Regency through cross-sectoral collaboration and develop the best model to be developed for this collaboration. This study uses a soft system methodology in the urban potable water supply system of Riau Province with a wide range of stakeholders through in-depth interviews, thematic analysis, and the creation of purposeful activity models and rich pictures to uncover and address complex issues. The study found that the implementation of collaborative water management in urban areas with the collaborative water governance approach has worked well in the short term. However, it has not enhanced organizational autonomy or fostered trust and reciprocity dimensions in the long term. Additionally, we emphasize the importance of a collaborative supervisory board that will open internal and external opportunities.

The limitation of machine learning methods for water supply and demand forecasting: A case study for Greater Melbourne, Australia

ABSTRACT Many cities around the world have faced water scarcity due to climate change, population growth, and urbanization. Accurate water supply and demand forecasting is critical for sustainable urban water management. Machine learning (ML) models provide new possibilities for forecasting compared with traditional models in handling non-linearity. This study aims to address the efficacy of ML models, long short-term memory (LSTM), stacked LSTM, bidirectional LSTM (Bi-LSTM), and multilayer perceptron (MLP), for forecasting water supply and demand in Greater Melbourne, Australia. The ML modelling utilized daily water supply and demand, and climatic variables (rainfall and maximum temperature) recorded by Melbourne Water and the Bureau of Meteorology from 1990 to 2019. The stacked LSTM performs better than other models in forecasting with R2, RMSE, and MAPE values of 0.908, 335.74 ML, and 23.5% for water supply and 0.791, 94.88 ML, and 5.3% for water demand, respectively. The inclusion of climatic variables enhanced the accuracy of forecasting by improving R2 and reducing RMSE and MAPE. The results indicate effectiveness of ML models, particularly LSTM-based architectures, in forecasting water supply and demand. However, these models have limitations, particularly in forecasting extreme values, emphasizing the need to improve ML models for more reliable and accurate water management.

Implementation of Nature-Based Solutions in Urban Water Management in Viet Nam, a Comparison among European and Asian Countries

Climate change is severely affecting all regions of the world, and urban water management has become a major urban challenge. Although nature-based solutions (NBSs) have been widely implemented in developed countries in the Global North to address stormwater-related challenges in urban areas, implementation of such approaches in Viet Nam and other Asian countries remains limited. In addition, comprehensive and critical reviews of NBS adoption and development processes in Viet Nam are scarce. This study aims to clarify several aspects through a literature-based review: to understand the development of urban water management in Europe and Asia (China and Southeast Asian countries) along with the drivers for NBS implementation in Viet Nam, to explain the barriers to NBS adoption in Viet Nam, to present feasible solutions for promoting NBS adoption, and to explore future perspectives for NBS development in the context of Viet Nam. Although significant barriers exist, opportunities for NBS implementation are evident. The findings of this study can be used to promote NBS in other municipalities in developing countries.

Assessing the influence of environmental variables on energy efficiency changes in the provision of drinking water services

Within the context of the water-energy nexus in drinking water provision, it is crucial to evaluate temporal shifts in energy efficiency. Utilizing the Stochastic Nonparametric Envelopment of Data (StoNED) approach, this research estimates longitudinal variations in the energy efficiency of drinking water services integrating multiple environmental variables. The analysis, conducted in England and Wales from 2008 to 2020, indicates that the source and quality of raw water, as well as population density, influenced the energy performance of water utilities. Quantitative findings evidenced marked disparity in energy efficiency among different companies, with an average efficiency of 0.617 and a range from 0.437 to 0.944. The dynamic assessment indicates an average annual enhancement of 1.1% in the sector, predominantly propelled by technical advancements (0.9%) rather than by improvements in efficiency (0.2%). This study emphasizes the critical need for bespoke policies and incentives to boost energy efficiency and support sustainable urban water management.

Examination of Water Use and Social Vulnerability: A Comparison of Four Communities in Alachua County, Florida

It is projected that about 30% of the world’s major cities will face severe water stress and urban drought from 2050 if climate change continues and has the anticipated effects (Florke et al, 2018; www.wrcwebsite.azurewebsites.net). Socio-economic drought, meaning water shortage in urban life, can have significant effects on a city’s inhabitants, including health and quality of life. Social and economic factors play an important role in planning and decision making of a society (Zhang et al, 2020). The analysis investigated the relationship between socio-economic factors and the use of potable water, its associated impact on aquifer recharge, and potentially identifying major factors influencing water demand and resource sustainability. The Centers for Disease Control and Prevention’s Social Vulnerability Index (SVI) and other measures were used for evaluating socio-economic factors. However, since SVI showed weak relationship with water use in the county and the neighborhoods, other socio-economic measures were assessed. Past research had found a correlation between water use and population, GDP, per capita income, electricity usage and irrigated land areas (Alacoma et al., 2007, www.usf.uni-kassel.de/watclim). Therefore, socio economic measures such as population density, household size, per capita income, and poverty rate and irrigation (with and without) potable water were analyzed to evaluate the relationship between water use patterns and these factors across the county and in the communities. The western communities had newer development and less parcels compared to the eastern with much older construction, which impacted their water use. Oakmont with separate reclaimed irrigation meter had lesser usage on potable water. Tioga on the other hand irrigated with potable water. Yearly SVI on a census tract level for the specific years of the study and other socio-economic measures such as population, per capita income, poverty, and household size were used in the analysis. The analysis was performed on four communities in Alachua County, Florida; two at the west and two at the east of the county. Socio-economic measures and physical features were evaluated for communities in the four locations to evaluate whether there is a relationship between water use patterns, spatial characteristics of development such as percent impervious and runoff, and measures of SVI. Spatial and basic statistics was used for this analysis. The western part of the county has had more intensive development in recent years compared to the eastern part of the county. The eastern communities have a high SVI and low potable water use per capita compared to the western communities. The number of households and population were the primary drivers of potable water use per census block. Percent impervious surface and runoff volume did not show any significant. relationship with a community’s SVI. At the parcel level, statistically significant differences were found between communities. For example, potable water use per parcel was lower in communities with high SVI. Keywords: water sustainability, urban water management, social vulnerability index, socio-economic factors, potable water use, aquifer recharge, reclaimed water use, runoff, imperviousness

Urban green streets and water management safety hubs in public schools lots

Abstract Green Stormwater Infrastructure (GSI) represents an effective approach to enhance urban resilience to climate change, contributing to runoff regulation and localized flood risk reduction. This study examines the potential for transforming open spaces in public schools into safety hubs for stormwater management in Mediterranean urban contexts, drawing on best practices from North America. Through a methodological analysis combining Research Through Design and an international literary scoping review, case studies of schools in the Metropolitan City of Naples are presented and compared with U.S. projects implementing GSI in school areas. The results highlight the importance of strategic coordination guidelines for local administrators, designers, and school principals, aimed at planning, designing, and managing highly performant green infrastructure networks. An integrated and shared metropolitan-level approach can maximize environmental benefits, transforming schools into community centers for urban resilience education and participatory management of risks related to extreme weather events.

Sustainable urban water management index for developing countries. A case study in Puebla City, Mexico

Several indicator and index frameworks have been reported to assess management efficiency and promote transparency, facilitating decision-making and innovation. However, they cannot be applied in cities with limited information, making them impractical. This study proposes a Sustainable Urban Water Management Index (SUWMI) for such cities, selecting six AquaRating indicators plus two indexes recommended in the Sustainable Development Goal 6, yielding a simplified and practical version for diagnosing the management performance rate of the Water Operating Systems (WOS) in cities. Conceptual and mathematical models were defined for SUWMI, and the eight selected terms were hierarchized based on a decision tree with the participation of an expert panel and further multicriteria decision-making methodology by the Analytic Hierarchy Process (AHP) to calculate the weighting parameters. The selected indicators represent five categories on a percentage scale. The highly populated Puebla City Metropolitan Zone in Mexico was the case study. Information was gathered from five Water Operation Systems (WOS) from 2002 to 2020. The tap water area's coverage and physical efficiency improved despite the population growth due to an adequate political strategy after 2014. The SUWMI values of each WOS diagnoses its performance, highlighting their differences and providing a valuable tool for guiding urban water public policy programs. The paper proposes a simple, fast, and easy-to-calculate index that can be helpful for a broader cluster of cities and urban settlements with deficient available information, which is common in developing countries.

Tracing Urban Drinking Water Sources: Global State of the Art and Insights From an IAEA‐Coordinated Research Project

ABSTRACTClimate change, inter‐annual precipitation variability, recurrent droughts and flash flooding, coupled with increasing water needs, are shaping the co‐evolution of socioeconomic and cultural assemblages, water laws and regulations, and equitable drinking water access and allocation worldwide. Recognising the need for mitigation strategies for drinking water availability in urban areas, the Isotope Hydrology Section of the International Atomic Energy Agency (IAEA) coordinated a state‐of‐the‐art global assessment to evaluate water sources and distribution of drinking water supply in urban centres, an initiative entitled ‘Use of Isotope Techniques for the Evaluation of Water Sources for Domestic Supply in Urban Areas (2018–2023)’. Here, we report on (a) current research trends for studying urban drinking water systems during the last two decades and (b) the development, testing and integration of new methodologies, aiming for a better assessment, mapping and management of water resources used for drinking water supply in urban settings. Selected examples of water isotope applications (Canada, USA, Costa Rica, Ecuador, Morocco, Botswana, Romania, Slovenia, India and Nepal) provide context to the insights and recommendations reported and highlight the versatility of water isotopes to underpin seasonal and temporal variations across various environmental and climate scenarios. The study revealed that urban areas depend on a large spectrum of water recharge across mountain ranges, extensive local groundwater extraction and water transfer from nearby or distant river basins. The latter is reflected in the spatial isotope snapshot variability. High‐resolution monitoring (hourly and sub‐hourly) isotope sampling revealed large diurnal variations in the wet tropics (Costa Rica) (up to 1.5‰ in δ18O) and more uniform diurnal variations in urban centres fed by groundwater sources (0.08‰ in δ18O) (Ljubljana, Slovenia). Similarly, while d‐excess was fairly close to the global mean value (+10‰) across all urban centres (10‰–15‰), reservoir‐based drinking water systems show lower values (up to ~ −20‰) (Arlington, TX, USA and Gaborone, Botswana), as a result of strong evapoconcentration processes. δ18O time series and depth‐integrated sampling highlighted the influence of the catchment damping ratio in the ultimate intake water composition. By introducing new, traceable spatial and temporal tools that span from the water source to the end‐user and are linked to the engineered and socio‐economic structure of the water distribution system, governmental, regional or community‐based water operators and practitioners could enhance drinking water treatment strategies (including more accurate surface water blending estimations) and improve urban water management and conservation plans in the light of global warming.

Sustainable urban water management: Evaluating two pilot-scale advanced decentralized treatment systems for removal of organic contaminants of emerging concern in reclaimed groundwater

The rapid growth of population and the effects of climate change have placed unprecedented pressure on urban water supplies and pollution control. Consequently, it is essential to explore new local water resources in water-strained areas. To this end, this work focuses on evaluating pollutant removal effectiveness of decentralized treatment systems for groundwater reclamation. Two pilot-scale treatment trains, Treatment Line 1 (L1) and Treatment Line 2 (L2), which use membrane-free (with granulated activated carbon as the main process) or membrane-based (with reverse osmosis as the primary technology), were compared for their effectiveness in reducing concentrations of organic contaminants of emerging concern (CECs). Additionally, the effect of sodium hypochlorite addition for biofilm control on the contaminant removal performance was also examined. Results from the analysis of nearly 120 trace organic compounds (only 21 were detected in the raw water) showed that L2 significantly overperformed L1. Furthermore, the addition of a pre-chlorination step did not improve the removal performance. Regarding trace organic compounds, L1 without pre-chlorination averaged an overall good removal performance (94 ± 12%). However, Irbesartan, gemfibrozil and gabapentin showed moderate removals (50–90%) and Valsartan was poorly removed (<50%). After pre-chlorinating L1, the overall removal performance decreased (86 ± 20%). Nearly one third of the target contaminants showed moderate removal (50–90%), with Irbesartan and Valsartan exhibiting poor attenuations (<50%), highlighting that negatively-charged compounds were challenging to eliminate. In contrast, L2 exhibited very high removals (>99%) on all studied trace organic contaminants regardless of pre-chlorination. Our study also identified several indicator compounds to monitor CEC removal. Finally, considering the trade-offs between cost and final water use (non-potable), L1-based schemes with intermittent pre-chlorination could be the preferred implementation option. The results of this work will offer valuable insights into decentralized treatment systems, assisting decision-makers in choosing suitable approaches for sustainable urban water management.

Urban Groundwater in the cities of Europe: hidden challenges in a changing climate

In European cities, groundwater remains an issue of significant concern, largely because it is “out of sight and out of mind.” The general public, and even decision-makers, possess only a limited understanding of the state and characteristics of this vital resource. As a consequence, problems related to groundwater quality or changing water tables/piezometric surfaces may persist for years, or even decades, without being adequately addressed-or worse, without being noticed at all before resulting in land subsidence,saltwater intrusion, deep migration of persistent organic contaminants like PFAS (Le monde, 2023) or other irreversible consequences. The urban water cycle is central to ensuring the supply of clean, safe drinking water, effective sanitation, and wellfunctioning drainage systems for millions of residents. The impacts of human activities, such as land use change, excessive water abstraction and mismanagement, and the discharge of wastewater can exert a far greater influence on groundwater systems and hydrogeology than climate change. These activities alter the quantity and quality of both surface and groundwater, raising complex scientific, technical, socio-economic, cultural, and ethical challenges in urban water management. It is important to address the many challenges associated with ensuring water security and safety in cities (Quevauviller et al., 2024), as well as for development of effective climate change mitigation and adaptation strategies for urban areas (IPCC, 2024). Groundwater plays a critical role in the green transition and is an integral component of most climate change mitigation and adaptation strategies (Ingemarsson et al., 2022), and for meeting the increasing demand for freshwater in cities due to accelerating urbanization (United Nations, 2022). Many urbanized areas in Europe already face poor chemical and quantitative status (EEA, 2024; Sentek et al., 2024), and global change including increasing populations and sea level rise pose a tremendous challenge for safe and secure water supply especially in coastal European cities. Open access to digital subsurface data e.g. through the European Geological Data Infrastructure supports societal needs and UN sustainable development goals (Hinsby et al., 2024). This special issue demonstrates some of the important issues that the water supply of European cities are facing in times of increasing competing use of the subsurface (Volckko et al., 2020), projected climate change impacts on the hydrological cycle (Henriksen et al., 2023) and with freshwater now being among the transgressed planetary boundaries (Richardsson et al., 2023). [...]

Multi-Channel Stormwater Ponds: A Sustainable Approach to Urban Flood Resilience

Flood-prone cities depend on stormwater ponds, but current designs with single, shallow channels limit storage. This paper proposes a new approach: using multiple channels to create smaller sections on the pond floor. Modeling shows this significantly increases storage for floods without needing a bigger pond. It also improves water flow and reduces stagnant areas. Finally, the paper explores practicalities for building these ponds, making them a valuable tool for better urban water management without needing more land or changing the pond’s height. These multi-channel ponds are particularly beneficial for frequent smaller storms by distributing water flow, reducing its speed, and allowing more time for sediment to settle, leading to improved water quality. Sustainable solutions are essential for safeguarding the future. In this research, sustainability plays a pivotal role, as the multi-channel stormwater pond design provides an innovative approach to improving flood management without the need for extra land or resources, thus supporting the goals of sustainable urban development.

Urban Water Management in Milan Metropolitan Area, a review

The increasing rate of urbanisation and extreme climatic events represent a constant threat for urban water resources management. In recent decades, Milan Metropolitan Area (Lombardy Region, Northern Italy) has been affected by a) frequent extreme rainfall events, responsible for the flooding of major surface water courses, and b) groundwater management problems, both from a quantitative (i.e. interaction with underground infrastructures) and qualitative point of view. Moreover, the increasing use of groundwater geothermal systems also requires further considerations. This work analyses the literature available in the area regarding surface floods, groundwater quantity, quality, and temperature. Finally, a discussion is provided to understand a) which approaches could promote an effective management of both surface water and groundwater resources b) which points of contact emerge between these two aspects of the urban water cycle, and c) which possible urban interventions could contribute to an integrated and functional management of water resources, also reducing some current issues.