CUANTIFICACIÓN ECONÓMICA Y COMPARATIVA DE REUTILIZACIÓN DE AGUAS RESIDUALES Y DESALACIÓN PARA USOS URBANOS

Coastal cities play a significant role in regional economic development and national water resource supply. However, the shortage of water resources in coastal cities has become a bottleneck for sustainable economic, social and ecological development. As a typical coastal city in Liaoning province, China, Yingkou has a relatively developed economy, but faces increasingly serious water shortages. Taking Yingkou as a case study, this study analysed the current situation of urban and rural water supply and conducted a rational estimation of the water supply and demand based on the time series method in the short‐term (2025) and long‐term (2035). Then, the allocation of urban and rural water supply was carried out on the principle of priority use of surface water, sufficient use of diverted water, expanding use of unconventional water and limited use of underground water. To achieve the optimal scheme, the method of ‘allocation‐feedback‐regulation‐reallocation’ was adopted to coordinate the water sources and consumption in different districts and sectors. Overall, the results clarified the red line of water consumption in 2025 and 2035 and defined water consumption and water sources in different sectors and districts. Finally, the water supply and demand balance in Yingkou and its subdistricts was achieved with surplus water rates of 6% and 7% in 2025 and 2035, respectively. Based on these results, suggestions for the sustainable development and utilization of water resources in Yingkou and coastal cities were proposed.

Cities on the Cantabrian coast, traditionally well-supplied by high rainfall, recently began to face tensions in their water supply due to climate change and pressure on resources, especially in large urban centers such as Bilbao and Santander. In cases like those mentioned, water supply has historically relied on transfers from the Ebro basin, the continuity of which could be compromised in the event of prolonged drought. In this new context, there is a need to explore sustainable alternatives that strengthen the resilience of the urban water system. In recent decades, significant progress has been made in wastewater reuse and desalination technologies. Although in the 1990s the urban reuse of reclaimed water was not regulated, today there is a specific regulation (R.D. 1085/2024) that defines the quality parameters required for various urban uses such as irrigation, water flushing, and cleaning. Real-life reuse cases in Spanish cities have been analyzed: Madrid uses more than 15 hm³ of reclaimed water per year, has a 700-km distribution network, and achieves a supply of 13 liters per inhabitant per day (lhd) for urban uses. Barcelona, for its part, allocates most of its reclaimed water to recharge the Llobregat River (indirect reuse), with a supply of 8 lhd. In the case of Seville, it uses 2.7 hm³/year and plans to reach 4 hm³/year, with a supply of 16 lhd. These values are influenced by factors such as rainfall, urban area, and available investment. In areas with more than 120 days of rain per year, such as Bilbao, the sustainable reuse of reclaimed water solely for urban purposes is not economically optimal; simpler logistical solutions such as tanker transport are often chosen. Current wastewater treatment plants (WWTPs) can achieve the required quality levels thanks to advanced tertiary treatments (activated carbon, ultrafiltration, UV radiation). In parallel, reverse osmosis desalination has evolved with standardized plants capable of producing more than 500,000 m³/d, making it a viable alternative for coastal cities with limited freshwater availability. The study presents both technologies based on a contextualized analysis that considers climatic and urban factors for the Bilbao metropolitan area.

To meet increasing urban water requirements in a sustainable way, there is a need to diversify future sources of supply and storage. However, to date, there has been a lag in the uptake of managed aquifer recharge (MAR) for diversifying water sources in urban areas. This study draws on examples of the use of MAR as an approach to support sustainable urban water management. Recharged water may be sourced from a variety of sources and in urban centers, MAR provides a means to recycle underutilized urban storm water and treated wastewater to maximize their water resource potential and to minimize any detrimental effects associated with their disposal. The number, diversity and scale of urban MAR projects is growing internationally due to water shortages, fewer available dam sites, high evaporative losses from surface storages, and lower costs compared with alternatives where the conditions are favorable, including water treatment. Water quality improvements during aquifer storage are increasingly being documented at demonstration sites and more recently, full-scale operational urban schemes. This growing body of knowledge allows more confidence in understanding the potential role of aquifers in water treatment for regulators. In urban areas, confined aquifers provide better protection for waters recharged via wells to supplement potable water supplies. However, unconfined aquifers may generally be used for nonpotable purposes to substitute for municipal water supplies and, in some cases, provide adequate protection for recovery as potable water. The barriers to MAR adoption as part of sustainable urban water management include lack of awareness of recent developments and a lack of transparency in costs, but most importantly the often fragmented nature of urban water resources and environmental management.

Investing upstream: Watershed protection in Piura, Peru

1. ABSTRACT Traditionally, the Gold Coast has relied heavily on sourcing water supply from dams in order to meet the city's water demand. Increasing climatic change, subsequent rainfall variability and long-term drought conditions in conjunction with a rapidly growing population however, have placed significant pressure on these supplies. In response, the Gold Coast City Council and Gold Coast Water have developed the Waterfuture Strategy to ensure the sustainability of the city's future water supply. The Gold Coast Waterfuture (GCWF) Strategy provides a multi-pronged approach to managing water resources and achieving first-rate outcomes in terms of environmental, social and economic sustainability. The Strategy aims to provide new bulk water supply sources whilst also improving on traditional water management and provision services. Projects undertaken as part of the Strategy include introducing rainwater tanks, recycled water systems, desalination, construction of the Southern Regional Water Pipeline (SWRP), raising of the existing Hinze dam, water conservation and demand management, and pressure and leakage management. Newly developing regions, such as the Pimpama Coomera area, provide opportunities to implement innovative ways to provide sustainable water, recycled water and wastewater services to the community as identified under the Pimpama Coomera Waterfuture (PCWF) Master Plan. The Waterfuture Strategies ensure a diversity of water supply sources and innovative water resource management for securing our Waterfuture whilst achieving environmental, social and economic sustainability. 2. GOLD COAST WATERFUTURE STRATEGY OVERVIEW It is well known that Australia is the driest inhabited continent on Earth with the most variable rainfall. Over the past 6 years, the Gold Coast and the Southeast Queensland region has experienced two of the worst drought periods on record, which has highlighted the vulnerability of the City's water supplies during severe climatic variation. This, combined with an increasing population has emphasised the need for a more integrated approach to how we use our water.

Applying Technology for Sustainable Water Management: The Pratt Water Experience

Analysis of hybrid Adiabatic Compressed Air Energy Storage - Reverse Osmosis desalination system with different topological structures

Prediction of Trihalomethanes in water supply of Chattogram city by empirical models and cancer risk through multi-pathway exposure

Agricultural water is affected by climate change and water management. Agricultural reservoirs are increasing demand on the environmental water supply because the Korean government has recently implemented an integrated water resource management policy. However, agricultural reservoirs are still in operation solely to supply agricultural water. To examine sustainable agricultural water management under climate change, we analyzed the strategy of operating regulations to efficiently distribute agricultural water as environmental water. We simulated the agricultural reservoir operation, analyzing its water supply capacity by applying operation regulations. The simulation predicted that future water supply capacity would decrease if the existing operation were maintained, and agricultural reservoir operation will be necessary in the future. The proposed reservoir operating strategy decreased the maximum water shortage and number of water shortage days compared with the existing operation with the required water supply. Our results can contribute to agricultural reservoir operation strategies and sustainable water management in response to climate change and provide decision-making guidance on water distribution for environmental use in response to water management policy changes.

Water conservation programs targeted at large users will play an integral role in securing water supplies for Australian cities in years to come. A hierarchical approach to water conservation – reducing consumption as a priority, then considering internal reuse of water and replacement of potable water with alternative sources – should be the key principle in sustainable water management. The application of this approach relies on a sound understanding of water consumption at a site: where water is used, why, when and how. This entails sub-and smart-metering of the water supply, and detailed analysis of site activities to produce a robust site water balance. The hierarchical approach can then be applied, and conservation options can be costed to assess financial viability. “Packaging” measures with different payback times together should be considered, along with funding support available. Based on implemented projects, an estimated 30% of potable water consumption within the commercial and industrial sectors could be saved at attractive payback periods. By adopting this sensible, integrated water conservation and management approach, the same outcomes can be achieved with less potable water consumption. Appropriate source substitution is a pillar of sustainable water supply, providing water at less environmental, social and financial cost than the alternatives.

1. Challenges in Management of Urban Water Resources.- Protection of Water Resources in the Slovak Republic.- J. Kris, M. Fasko.- The Human Dimensions of IWRM: interfaces between knowledges and ambitions P. Jeffrey.- Supporting the siting of new urban developments for integrated urban water ressource management D. Butler et al.- GSI for integrated water resources management O. Udovyk.- Urban infrastructure modelling K. Pryl, Z. Svitak.- Integrated urban water cycle modeling T. Metelka.- Water Resources Policy and Management in Jordan N. K. Al-Halasah, B.Y. Ammary.- Urban Water Resources Management in Ukradne V. Kuznyetsov.-Water Supply, Urban Drainage and waste water treatment in the Orava region R. Haloun .- 2. Challenges in Urban Water Supply .- Robust design and management of water systems: how to cope with risk and uncertainty? D. Savic .- Ageing and renewal of urban water infrastructure R. Baur .- Benchmarking of Water Supply Systems - Water Losses Assessment K. Tothova et al..- Water Supply of Bucharest - Past, Prezent, Future: a study case E. Chiru.- Water supply in cities of Belarus: Water quality and risk management T. Kukharchyk, V. Khomich .- Risk Assessment of potable water used from river intakes near radiation - dangerous objects (Obninsk for illustration) O.Momot et al.- 3. Urban drainage and water bodies.- Wastewater network challenges and solutions S. Saegrov et al. - Application of decision support system for sewer network rehabilitation P. Hlavinek et al.- Implementation of fiber optic data cables in sewage system S. Stanko, I. Mahrikova.- Overview of urban drainage impacts on aquatic habitat J. Marsalek .- Urban Runoff - Contamination, Problems of Treatment and Impact on Receiving Water A. Aucharova, V. Khomich .- Impact of anthropogenic loads on water quality of rivers of the upper areas of Oka and Desna basins I. Semanova et al.- Biosorbents in surfare waters in situ treatment against radionuclides L. Spasonovaet al.- Wastewater Treatment and Security.- Economic and Technical Efficiency of Wastewater Plants: a basic requisite to the feasibility of water reuse projects F. Hernandez-Sancho, R. Sala-Garrido .- Joint optimisation of sewer and treatment plant kontrol H. Kroiss.- Wastewater treatment in Belarus: purification efficiency and surface water pollution risk O. Kadatskaya.- 4. Wastewater Treatment and Reuse.- Water reuse in Canada: opportunities and challenges K. Exall et al.- Integrated concepts for reuse of upgraded wastewater - role of membranes in water recycling T. Wintgens et al.- Water reuse feasibility study in the czech republic B. Janosova et al. Alternative formulations for the reuse of treated wastewater in menemen plain irrigation scheme O. Gunduz et al.- Assessment of Rainwater Roof Harvesting Systems for Household Water Supply in Jordan F. A. Abdulla, A. W. Al-Shareef .- Wastewater Reuse for Irrigation on the Desert Sandy Soil of Egypt: long-term effect H. I. Abdel-Shafy, M. F. Abdel-Sabour.- Membranes for Unrestricted Reuse R. Messalem.-

ABSTRACTMilpa Alta, located southeast of Mexico City, is a key region for environmental sustainability due to its volcanic soil, biodiversity, and critical role in aquifer recharge, which supports the city's water supply. However, rapid urbanization has severely impacted the area, causing reduced vegetation cover, increased runoff, and diminished groundwater recharge, which intensify flooding, soil erosion, and water scarcity. This study aims to identify optimal sites for managed aquifer recharge (MAR) structures in Milpa Alta through a multi‐criteria analysis incorporating criteria such as topography, land use, proximity to urban areas, and drainage networks. Uniquely, hydraulic simulations of flood scenarios were integrated into the analysis to improve the precision of site selection. Geographic information systems (GIS) were used to assess and combine these criteria, providing a spatial evaluation of suitability. Results indicate that the central and northern regions of Milpa Alta, particularly around San Francisco Tecoxpa and San Antonio Tecómitl, are most suitable for MAR implementation due to their permeable soils, gentle slopes, and proximity to agricultural lands and drainage networks. These MAR structures can enhance groundwater recharge and mitigate flood risks during extreme rainfall events, with the potential to capture up to 300,000 m3 of surface runoff during a single high‐intensity storm event. Despite its strengths, the study acknowledges limitations such as the absence of detailed water quality analyses and the need for sensitivity testing of the criteria weighting. This research provides an innovative approach to MAR site selection by integrating flood simulations, offering a replicable model for similar regions. Successful implementation of MAR in Milpa Alta requires addressing water quality concerns, engaging stakeholders, and ensuring compliance with regulatory frameworks. The findings emphasize MAR's potential to balance urbanization pressures with sustainable water management and flood mitigation strategies in Mexico City's rapidly developing areas.

This article explores the imperative of integrating UNFCCC water efficiency standards in naturally deforested regions, focusing on the United Arab Emirates (UAE) as a case study. As the global climate crisis intensifies, preserving and efficiently utilizing water resources is crucial, particularly in arid regions like the UAE with scarce water supplies. Leveraging mechanisms from Article 6 of the Paris Agreement, this study investigates the potential for crediting water efficiency initiatives in deforested areas where desalination predominates. Through an interdisciplinary approach, encompassing environmental science, hydrology, horticulture, policy analysis, and socio-economic considerations, the research assesses the feasibility of incorporating UNFCCC water efficiency standards into regional sustainability frameworks. Key components include evaluating current water management practices with indigenous plants such as Prosopis cineraria, Ziziphus spina-christi, and Phoenix dactylifera, analyzing deforestation's environmental impact on water resources, and exploring policy frameworks promoting water efficiency. Additionally, the study addresses socio-economic factors influencing water generation and usage patterns, considering the role of incentive mechanisms and private sector integration. The findings highlight the challenges and opportunities of applying water efficiency standards under the Paris Agreement’s Article 6 crediting mechanism in deforested regions. The UAE case study offers insights into sustainable water management in environmentally constrained nations, focusing on reverse osmosis desalination, the environmental footprint of various power sources, and managing distances between desalination plants and water generation sites. This research underscores the importance of proactive policy interventions and international collaboration in addressing water scarcity and advancing towards sustainable, climate-resilient futures.

The gap between water supply and demand is increasing in several urban clusters of the world. This study uses the water evaluation and planning model to assess the water supply and demand dynamics in one of the large metropolitan regions of the Chennai hydrological basin. The primary water supply sources, including reservoirs, groundwater, inter-basin transfer, and desalination plants, were integrated into the model to simulate the current and future water demand and supply scenario. Three rainfall scenarios (excess, normal, and deficit) were utilized to assess their impacts on water supply. The study highlights the increase in unmet demand for normal and deficit rainfall scenarios. In response, various mitigation options were explored, including increasing groundwater recharge, reservoir capacity enhancement, water treatment plant expansion, additional storage, and utilization of water stored in rock quarries. The findings provide valuable insights for policymakers and stakeholders to develop sustainable water management strategies in the Chennai Basin.

Examining the potential for energy-positive bulk-water infrastructure to provide long-term urban water security: A systems approach