Water Management and Environmental Engineering: Current Practices and Opportunities

1. Introduction and Scope

Water is a vital resource for both agricultural and industrial operations, which cumulatively account for more than 90% of the worldwide freshwater use [1]. However, the overexploitation of freshwater resources has been causing alarming water scarcity issues, leading 50% of the global population to face severe droughts by 2050 [2]. In this light, the United Nations [3] have introduced the Sustainable Development Goals (SDGs) to set unequivocal eco-friendly targets by 2030, aiming indicatively at the universal and equitable clean water access (SDG#6) and the responsible use of natural resources, including freshwater (SDG#12). Notably, as freshwater preservation constitutes a major challenge from the perspectives of environment, society, and economy [4], the implementation of water management interventions, based on environmental engineering principles, has become more imperative than ever.

To this end, it is crucial that vigorous practices and state-of-the-art solutions for water monitoring, optimization, and management should be developed to eliminate industrial and societal risks related to water shortages and degradation. This Special Issue aims to tackle current and future water-related complications, through the lens of environmental engineering, in the following key research areas: (i) freshwater resources management in agriculture and industry; (ii) urban water management and wastewater treatment; and (iii) smart water monitoring and management. In the following section, a brief description of the research scope, the outcomes, and the contributions of the articles submitted to this Special Issue is provided.

2. Scientific Contributions

2.1. Supply Network Configurations under a Water Footprint Cap

Aivazidou et al. [5] developed a mixed-integer linear programming model to minimize the operational costs of a wine supply network using a water footprint constraint. The outcomes revealed that the network’s configurations vary considerably subjected to the values of the water cap to balance the trade-off between economic and water-related performance. The proposed model could act as a guide map for stakeholders to set joint sustainable targets regarding water use across supply chains.

2.2. Modular IoT System for Intelligent Water Metering

Syrmos et al. [6] designed a modular monitoring IoT system for both quantitative and qualitative smart water metering to improve operational reliability. The suggested model could be used in both urban and rural regions and be scaled up to a modern water infrastructure, enabling both water providers and decision-makers (e.g., governmental authorities, global water organizations) to perform efficient consumer profiling and supervise optimal decisions in water-scarce conditions.

2.3. Water and Carbon Footprints Assessment of Biomass Production

Angnes et al. [7] calculated the water and carbon footprints of two commonly used irrigation systems (i.e., center pivot, drip). The results revealed that the materials used for pipes and filters have the most significant effect on the water and carbon footprints, while the irrigated area impacts on the two systems differently. The outcomes could support practitioners in the development of sustainable irrigation practices that reduce environmental impacts and enhance agricultural yields.

2.4. Optimal Scheduling of Rainwater Collection Vehicles

Alnahhal et al. [8] proposed two mixed integer programming models to optimally schedule water tankers collecting the extra rainwater from streets to be used in agriculture and industry. Two genetic algorithms were employed to solve the models faster. The results highlighted that both mixed integer programming and genetic algorithms generate optimal solutions for small problems, as well as good estimations for larger ones, considering a reasonable number of iterations in both cases.

2.5. Water Management in Shale Gas Extraction

Badjadi et al. [9] introduced an innovative step-rectangular pulse hydraulic fracturing method to optimize water usage during shale gas extraction. The results indicated that the proposed method offers superior pressurization and more complex fracture networks, reduces water consumption, and increases shale gas production. This research could provide guidance for field implementation in hydraulic fracturing operations by promoting efficient water management and environmental sustainability.

2.6. Heuristic and Data-Driven Water Management for Precision Agriculture

García et al. [10] applied control theory to precision agriculture irrigation systems, based on soil moisture measurements, for obtaining water savings. The developed water allocation algorithms were based on real-time computing, such as dynamic priority and feedback scheduling. The results showcased that the data-driven water allocation strategies reduce water usage in closed-loop control systems and prevent crop water stress due to the controlled access to irrigation water.

3. Concluding Remarks

Overall, this Special Issue contributes to shedding light on contemporary challenges, trends, and opportunities for efficient water management to mitigate freshwater consumption and pollution in agricultural, industrial, and urban contexts. The submitted papers could act as environmental engineering tools and methodological guidelines of state-of-the-art water stewardship practices. These efforts could also pave the way for future research to advance this scientific field by offering novel operational directions. Finally, we envisage that this Special Issue will ignite a broader discussion on freshwater resource preservation and management through the prism of digital sustainability.