Advances in Dam Engineering of the 21st Century

The 21st century has emerged as a transformative era for dam engineering, shaped by rapid technological innovation, heightened environmental awareness, the progressive aging of existing infrastructure, and an urgent global call for climate resilience. As the demand for water resources, renewable energy, and sustainable infrastructure continues to grow, the role of dams has evolved far beyond their traditional functions. Today, dams are not only vital components of critical civil infrastructure, but they are also at the forefront of innovation, sustainability, and adaptive design and maintenance. Challenges and needs for the dam industry, outlined in ICOLD Bulletin No. 185 (Bulletin No. 185–Challenges and Needs for Dams in the 21st Century), can be categorized into four major areas:

• The growing need for additional freshwater resources to support population growth, agriculture, and industrial development.
• Integration of hydroelectric power with alternative renewable energy sources to meet increasing global energy demands and enhance energy system flexibility.
• Adaptation to climate change, which affects water availability, flood control, and hydropower generation.
• Navigating financial, environmental, and social constraints to ensure that dam projects are economically viable, environmentally sustainable, and socially acceptable.

This Special Issue, “Advances in Dam Engineering of the 21st Century”, presents a collection of 12 articles that highlight significant advancements in a wide range of dam engineering disciplines. These contributions reflect the latest developments in materials technologies, design methodologies, construction techniques, monitoring techniques, and comprehensive risk management strategies.

This volume continues the task initiated in the first Special Issue on the subject, Advances in Dam Engineering [1], published in 2020. By bringing together insights from leading engineers, researchers, and practitioners, this edition captures the cutting edge of innovation that is shaping the future of the dam industry. It serves as both a reference and a forward-looking guide for professionals, academics, and decision-makers engaged in the planning, design, operation, and rehabilitation of dam infrastructure in a rapidly changing world.

• Digital Technologies and Computational Tools

Among the many factors that have influenced the development of dam engineering over the past two decades, the computer technology, expansion of the internet and integrated connectivity, and the broader digital transformation stand out as the most significant. These advances have revolutionized nearly every aspect of dam engineering, from conceptual design and structural analysis to construction management, real-time monitoring, and predictive maintenance.

High-performance computing and advanced numerical modeling have allowed engineers to simulate complex coupled hydraulic, geotechnical, and structural behaviors with unprecedented precision, improving both design accuracy and safety assessments. Contributions to the development of standardized verification and validation procedures in recent years have built credibility and confidence in the results of advanced dam analyses [2].

Integration of Building Information Modeling (BIM), Geographic Information Systems (GIS), and digital twin technologies [3] (in the context of dam engineering, data-driven models that mirror the physical life-cycle of dams from design and construction through operation and maintenance) has enhanced interdisciplinary collaboration and significantly improved dam health monitoring and decision-making throughout the entire dam life-cycle.

At the same time, the widespread adoption of remote sensing technologies, Unmanned Aerial Vehicles (UAVs), and IoT-enabled sensors has transformed dam safety monitoring. These tools allow for continuous, real-time data acquisition and the implementation of early warning systems, which greatly reduce operational and structural risks.

Finally, machine learning (ML) and artificial intelligence (AI) are increasingly being applied to detect anomalies in structural behavior, optimize weather forecasts and reservoir operations, and support adaptive management strategies [4].

• Innovations in Materials and Construction Technologies:

The 21st century has witnessed remarkable advances in the materials and construction technologies used in dam engineering. These innovations have significantly enhanced the efficiency, durability, and safety of dam structures, while also enabling more sustainable and cost-effective solutions (ICOLD Bulletin 165–The sustainability of concrete dams: Volume 1–Design and construction in progress). Key developments include:

• Implementation of innovative Cemented Material Dam (CMD) technology in engineering practice, which utilizes a cementitious binder combined with various natural or manufactured materials in dam construction. Although CMD is still in the early stages of development, related technologies, such as Faced Symmetrical Hardfill Dams (FSHD), Cemented Sand and Gravel (CSG), Cemented Sand, Gravel, and Rock (CSGR), and Rock-Filled Concrete (RFC) (ICOLD Bulletin 190–Cemented Material Dam: Design and Practice-Rock-Filled Concrete Dam), and Cemented Soil Dams (CSD) (ICOLD Bulletin 195–Cemented material Dams: Design and Practice Cemented Soil Dams) shows promising potential for further advancement.
• The continued evolution of Roller-Compacted Concrete (RCC) (ICOLD Bulletin 177–Roller-Compacted Concrete Dams) technology has enabled more streamlined dam construction, contributing to reduced construction time, improved quality, and cost-effectiveness.
• Use of geosynthetics for separation of dissimilar materials and ground improvements for earth and rock-fill dams.
• Extending the service life of dams through modern repair and mitigation techniques, such as sealing cracks with self-healing concrete and installing impermeable membranes to prevent seepage.
• Improved precision, efficiency, and safety in dam construction through the adoption of automation and robotics, enabling material placement and inspection to be performed with greater accuracy.
• Advancing and implementing modern laboratory testing methods, such as the Digital Image Correlation (DIC) system, to enhance the accuracy of material behavior analysis and structural performance assessment.
• Implementing advanced nondestructive testing (NDT) methods of dams in the field, including impact-echo, photogrammetry, digital profilometry, ambient vibration testing, fiber optics, Interferometric Synthetic Aperture Radar (InSAR) and long-range geologic LiDAR, to assess structural integrity and detect subsurface anomalies without damaging the dam structure.
• New technologies in tailings dam design include advanced dewatering methods such as high-density thickening, paste thickening, and filtration, which improve water recovery and reduce storage risks. Cycloning separates coarse and fine fractions for optimized embankment construction. Emerging practices such as mud farming, geotextile tubes, and centrifuges enhance desiccation and stability. Tailings stream separation—by physical or geochemical properties—enables targeted management of acid-generating materials. Integrated tailings and waste rock storage improve structural safety and environmental performance. These innovations support safer, more sustainable tailings facilities customized to site-specific conditions to reduce physical and environmental risks. Significant effort has been put into advancing the tailing dewatering (filtration) technologies with a goal of improving safety and water recovery (ICOLD Bulletin 181–Tailings Dam Design–Technology Update).

• Enhancement of Engineering Knowledge:

Internet connectivity and cloud-based platforms have significantly enhanced global collaboration in dam engineering, enabling seamless data sharing and improved access to technical information and best practices. These tools allow engineers and researchers to collaborate across borders and disciplines more effectively than ever before.

The availability of centralized dam databases, such as those maintained by ICOLD (ICOLD World Register of Dams, https://www.icold-cigb.org, accessed on 19 November 2025) and national dam registries, as well as international benchmarking initiatives (ICOLD Bulletin on Capitalization of the results related to Benchmark Workshops on Numerical Modelling) [2], has facilitated comparative analysis across various dam types and performance metrics. Access to technical publications, including ICOLD bulletins, national committee guidelines, and policy documents, further supports the standardization and dissemination of best practices.

Moreover, the growing availability of performance records and case studies of dam failures, such as those compiled in ICOLD Bulletin 188 (ICOLD Bulletin 188–Statistical Analysis of Dam Failures), provides valuable insights into long-term behavior, failure mechanisms, and lessons learned. This shared knowledge base promotes international collaboration, enhances risk management, and contributes to the continuous improvement of dam engineering practices.

A particularly critical area of advancement in 21st-century dam engineering is the expansion and use of seismic records–forming a large empirical database for analysis and a potential training library for ML applications. The expanded datasets include ground motions with diverse durations and frequency content, enabling a more reliable selection of the seismic records for simulations of dams. These developments are instrumental in refining seismic design criteria, enhancing resilience, and expanding engineering knowledge for infrastructure in seismically active regions.

• Where the Field is Heading: Priorities for the Next Decades

Looking across the contributions in this Special Issue–and the broader arc of practice–the following areas emerge as pivotal for shaping future developments in dam engineering over the coming decades:

• Risk-informed decision process. Engineering practice has long sought the collective establishment of a modern, integrated framework for dam safety. Central to this evolution is the adoption of risk-informed decision-making (RIDM), which integrates technical, legal, and governance perspectives. ICOLD Bulletin 189 (ICOLD Bulletin 189–Current state-of-practice in risk-informed decision-making for the safety of dams and levees) outlines global practices in RIDM; Bulletin 191 (ICOLD Bulletin 191–Dam Safety: Concepts, Principles, and Framework) defines core safety principles, lifecycle management strategies, and owner responsibilities; and ICOLD Bulletin 192 (ICOLD Bulletin 192–Dam Safety: Governance Considerations) focuses on governance structures, legal liability, and regulatory models. Together, these bulletins advocate a shift from prescriptive to adaptive, risk-based approaches—promoting transparency, stakeholder engagement, and continuous improvement to enhance dam safety, resilience, and public protection across diverse national contexts.
• Adaptation non-stationary hazards. Non-stationary hazards—such as increased frequency, intensity, or duration of extreme rainfall events; shifts in snowmelt runoff patterns; rising temperatures affecting reservoir evaporation; urbanization; and evolving seismic risks due to tectonic activity—are driven by environmental, climatic, geological, and human factors. In dam engineering, this concept is critical, as traditional design and risk assessments often assume stationary hazard conditions (e.g., floods, earthquakes) that remain statistically constant over time (ICOLD Bulletin 142–Safe passage of extreme floods). Addressing non-stationary hazards requires adaptive approaches in dam design, rehabilitation, and interventions throughout the dam’s operational life.
• Advanced computation models. The growing use of advanced computational models in dam engineering—for structural, hydraulic, seismic, and sedimentation simulations—necessitates rigorous verification, validation, and uncertainty quantification (VVUQ) to ensure credibility and build confidence in the results (ICOLD Bulletin 140–Mathematical Modeling of sediment transport and deposition in reservoirs; ICOLD Bulletin 155–Guidelines for use of numerical models in dam engineering; ICOLD Bulletin 206–Non-linear modeling of concrete dams). These VVUQ practices are essential to confirm that models are accurate, reliable, and representative of real-world behavior [5].
• Resilience and functional recovery. Translate damage states into functionality and time-to-recovery for water delivery and hydropower; integrate fragility with restoration logistics, supply chains, and downstream consequences.
• Life-cycle risk and asset management. Effective management of dam safety and performance over time: it is essential to couple reliability with cost, schedule, and operation disruption risk. This integrated approach enables more informed decision-making by balancing safety with operational and financial constraints. Formalizing risk-informed planning allows dam owners and operators to prioritize staged rehabilitation, instrumentation upgrades, and dam and appurtenant structure modernization based on quantified risk profiles and asset condition. This ensures that limited resources are allocated efficiently, interventions are timed to minimize service disruptions, and safety margins are maintained (ICOLD Bulletin 130–Risk Assessment in Dam Safety Management; ICOLD Bulletin 167–Regulation of Dam Safety: An overview of current practice worldwide; ICOLD Bulletin 189–Current state-of-practice in risk-informed decision-making for the safety of dams and levees).
• Dam aging and decommissioning. Aging dams pose increasing safety, environmental, and operational challenges due to structural deterioration, outdated design standards, and evolving societal expectations. When dams reach the end of their useful life, decommissioning becomes a complex process requiring multidisciplinary expertise, regulatory oversight, and stakeholder engagement. Key challenges include managing residual risks, ensuring environmental protection, and securing funding. Effective decommissioning must maintain safety throughout, with robust control of inflows and sediment, and long-term monitoring to protect downstream communities and ecosystems (ICOLD Bulletin 160–ICOLD Dam Decommissioning–Guidelines; ICOLD Bulletin 198–ICOLD Ageing of Concrete Dams).
• Sustainability and sediment. Sedimentation poses a major threat to reservoir sustainability, reducing storage capacity, damaging turbines, and impacting downstream ecosystems. ICOLD Bulletins (ICOLD Bulletin 147–Sedimentation and sustainable use of reservoirs and river systems; ICOLD Bulletin 182–Sediment management in reservoirs: National regulations and case studies; ICOLD Bulletin 193–Sediment Bypassing and Transfer) highlight global trends and promote integrated sediment management strategies, including bypass systems, sluicing, and adaptive operations. It introduces a life-cycle economic model to evaluate sedimentation impacts and emphasizes fluvial morphological assessments to mitigate downstream degradation. These advances mark a shift in dam engineering—from reactive to proactive sediment control—ensuring long-term functionality, environmental integrity, and economic viability of reservoirs worldwide.
• Open, reproducible workflows. Standardize data schemas, model notebooks, and validation reports to accelerate learning across owners and regulators while protecting sensitive information.

• Published Papers in this Special Issue

The collection of twelve papers in this Special Issue presents a comprehensive view of modern dam engineering, spanning advanced modeling, risk assessment, material behavior, and safety governance. Together, these papers outline a full pipeline for contemporary dam safety practice—from hazard definition to structural modeling, material testing, and policy evolution. The papers collectively advance three central themes: (i) Integration of Models and Measurements: emphasizing tighter coupling between simulations and real-world data to reduce epistemic uncertainty. (ii) Decision-Ready Metrics: promoting performance indicators—such as capacity, fragility, and recovery—that are meaningful to dam owners and regulators. (iii) Scalable and Practical Tools: leveraging efficient computation, surrogate modeling, and interpretable analytics to support real-world adoption.

Taken together, these twelve articles read trace a full pipeline for modern dam safety: from how we define the hazard and set design targets, through system-level modeling that couples dam–reservoir–foundation dynamics, extending down to local interfaces and materials that often control failure, plus embankment hydraulics, and finally evolving governance and safety practice.

(1)

Effect of Ground Motion Duration and Frequency Characteristics on the Probabilistic Risk Assessment of a Concrete Gravity Dam [6]

This study brings ground-motion duration and frequency content to the foreground of probabilistic risk assessment (PRA) for concrete gravity dams—features often collapsed into scalar intensity measures. The authors assemble suites of earthquakes with contrasting durations and spectral shapes and propagate those differences through the full PRA chain: nonlinear seismic response, fragility construction, and risk metrics. By holding other modeling elements constant and varying the motions’ time–frequency attributes, they show that estimated safety margins and exceedance probabilities are not invariant to duration or spectral content. The message is practical and consequential: when cumulative damage mechanisms or nonlinear response are in play, duration and frequency should be treated as first-class inputs for record selection and intensity-measure choice, rather than handled implicitly. The findings invite feature-aware hazard characterization in dam risk studies and provide a roadmap for analysts to test the sensitivity of risk estimates to alternative record sets before locking in conclusions.

(2)

A Finite Element Formulation for True Coupled Modal Analysis and Nonlinear Seismic Modeling of Dam–Reservoir–Foundation Systems: Application to an Arch Dam and Validation [7]

The paper presents a unified finite element formulation that performs true coupled modal analysis in a manner consistent with subsequent nonlinear time-history simulations of the dam–reservoir–foundation (DRF) system. Applied to a thin arch dam, the formulation carries identical coupling assumptions from modal characterization directly into the nonlinear dynamic stage, avoiding the common inconsistency of mixing uncoupled modes with coupled transients. Comparisons with added-mass and other approximate representations highlight where those shortcuts may miss phase relationships and energy exchange with the fluid and foundation. The application and validation demonstrate that maintaining coupling consistency improves the physical fidelity of stress and damage predictions and makes modal insights genuinely transferable to nonlinear runs. The result is both a methodological contribution and a practical template for teams that want to align system identification, modal testing, and production analyses without sacrificing computational tractability.

(3)

Effect of Contraction and Construction Joint Quality on the Static Performance of Concrete Arch Dams [8]

Focusing on a critical but often under-specified ingredient in arch dams, this work evaluates how the quality of contraction and construction joints influences static performance. Through parametric numerical models, the authors vary bonding, stiffness, and roughness conditions and examine the resulting stress redistributions, displacement patterns, and potential hot spots. The results are clear: realistic joint characterization can govern stress paths and apparent capacity margins, such that optimistic assumptions mask vulnerable zones while overly conservative ones may prompt unnecessary strengthening. By mapping performance shifts to specific joint properties, the study underscores the value of targeted inspection, testing, and as-built documentation to calibrate joint models. For assessment and retrofit design, it argues for elevating joint realism from a modeling detail to a primary source of epistemic uncertainty that should be explicitly managed.

(4)

System Reliability Analysis of Concrete Arch Dams Considering Foundation Rock Wedges Movement: A Discussion on the Limit Equilibrium Method [9]

This contribution reframes arch dam stability where foundation rock wedges can move, replacing isolated checks with a system reliability perspective and scrutinizing how limit-equilibrium (LE) methods are used in practice. The authors treat wedge movement and structural response as interacting components in a coupled failure model, then dissect the assumptions and data needs embedded in common LE formulations. By acknowledging interaction and correlation among wedges, joints, and the arch, the framework yields failure probabilities that differ materially from serial, independent checks. The discussion neither dismisses LE nor overstates its reach; rather, it clarifies when LE can be informative and when it risks biasing safety evaluations. The recommended path is reliability analysis that reflects interaction and dependency, supported by data that tighten key uncertainties in rock mass properties and interface conditions.

(5)

Numerical Modeling of Cracked Arch Dams: Effect of Open Joints during the Construction Phase [10]

Addressing the underexamined role of construction staging, this paper explores how open joints and early-age cracking in arch dams precondition the stress field carried into operation. The authors build staged numerical models that allow joint opening and simulate cracked media during construction, then follow how these states evolve under service loads. The analysis shows that joint behavior during erection is not merely a transient curiosity; it can seed stress concentrations and preferred crack paths that persist, affecting long-term performance and vulnerability. The practical recommendation is to bring explicit, joint-aware construction staging into assessments of existing arches and into the planning of retrofits—especially when historical records indicate joint opening, differential set, or construction sequence anomalies that could have left durable imprints on the structure.

(6)

Modeling Variability in Seismic Analysis of Concrete Gravity Dams: A Parametric Analysis of Koyna and Pine Flat Dams [11]

Using two canonical gravity dams—Koyna and Pine Flat—this parametric study quantifies how modeling choices propagate to dispersion in seismic response predictions. Across three software platforms for 2D models, the authors contrast linear versus nonlinear behavior of the dams and compare reservoir representations (Westergaard added mass versus acoustic domains), evaluating modal properties and crest displacement time histories. The results reveal nontrivial spread across defensible choices, illustrating how solution strategy, material nonlinearity, and fluid–structure interaction level each shape outputs. The paper proposes a pragmatic analysis hierarchy: start with simpler, transparent models to map sensitivities and only add complexity when it materially reduces uncertainty in the decision variables. In doing so, it normalizes variability as an expected feature of the problem and models epistemic uncertainty openly, rather than burying it in a single “best” configuration.

(7)

Delving into Earth Dam Dynamics: Impact of Inner Impervious Core and Toe Drain Arrangement on Seepage and Factor of Safety during Rapid Drawdown [12]

This study examines how inner impervious cores and toe drain configurations affect seepage and slope stability in earth dams during rapid drawdown. Using physical and computational models, it reveals that steeper slopes without toe drains show significant instability and deviation from analytical predictions. Key findings include strong correlations between matric suction, water conductivity, and factors of safety. For engineering practice, the research underscores the critical role of dam geometry and drainage design in ensuring structural integrity. These insights support more resilient, data-driven approaches to dam design, enhancing safety, performance, and longevity in real-world geotechnical engineering applications.

(8)

Testing the Shear Strength of Mass Concrete Lift Lines: A Comparison of Procedures [13]

This laboratory study compares two direct shear procedures for assessing mass-concrete lift lines using cores from Thief Valley Dam: a matrix-based approach with variable normal loading across specimens and the multistage ASTM D5607 method. By design, the matrix procedure captures true peak sliding behavior and degradation without repeatedly damaging the same surface, whereas the multistage approach shears one interface multiple times at increasing normal stress. The head-to-head results show that multistage testing can degrade the shear plane and bias derived parameters—tending to depress friction angle and inflate apparent cohesion—thus obscuring the genuine peak resistance. The matrix-based protocol yields clearer characterization of strength evolution with displacement and offers lab-ready guidance to reduce procedural bias in safety evaluations where lift-line behavior is a governing uncertainty.

(9)

On a Benchmark Problem for Modeling and Simulation of Concrete Dams Cracking Response [14]

This study revisits a classical benchmark for validating FE software in modeling concrete dam cracking, using Carpinteri et al.’s (1992) pre-notched gravity dam experiment. The authors apply Abaqus’ Concrete Damage Plasticity model and compare simulation results with experimental data to assess mesh refinement, element types, and tensile softening laws. The study reinforces benchmark-based validation as essential for ensuring reliable nonlinear FE simulations of quasi-brittle concrete structures. Key findings show that bilinear softening and targeted mesh refinement improve accuracy. The study highlights that agreement in load–crack mouth opening displacement curves alone is insufficient for validation and that the crack trajectory matters. For engineering practice, it underscores the importance of rigorous model validation to ensure reliable, efficient, and physically meaningful FE simulations in structural safety assessments.

(10)

A Comparison of Return Periods of Design Ground Motions for Dams from Different Agencies and Organizations [15]

Providing a clear landscape view of seismic hazard targets for dams, this review compares the return periods and hazard approaches used by thirteen agencies and organizations, spanning deterministic, probabilistic, and hybrid practices and situating dams relative to other infrastructure classes. A central observation is that many agencies converge on design motions with return periods around 10,000 years for high-consequence dams. The U.S. Bureau of Reclamation is notable for not prescribing a fixed return period, instead using explicitly risk-informed decisions guided by consequence thresholds and internal standards; yet the comparison shows this philosophy aligns with peers that have likewise embraced risk-informed processes. For owners and regulators, the paper functions as a compact reference when selecting hazard targets and justifying risk-based alternatives.

(11)

Dam Safety History and Practice: Is There Room for Improvement [16]?

This article presents a comprehensive historical review of dam safety practices, tracing their evolution from empirical methods to modern standard-based and risk-informed approaches. It highlights the growing complexity of dam safety due to aging infrastructure, climate change, and socio-environmental demands. The authors argue for integrating systemic methodologies, such as General Systems Theory, to enhance transparency, reproducibility, and stakeholder engagement. For engineering practice, especially in structural and civil disciplines, this work underscores the need for adaptive, data-driven safety frameworks that balance technical rigor with societal expectations—critical for sustainable infrastructure management and resilient dam safety governance.

(12)

Seismic Behavior of Rock-Filled Concrete (RFC) Dam Compared with Conventional Vibrating Concrete (CVC) Dam Using Finite Element Method [17]

This study compares the seismic performance of Rock-Filled Concrete (RFC) and Conventional Vibrating Concrete (CVC) gravity dams using FE analysis. Results show RFC dams exhibit lower stress, reduced displacement, and significantly less damage under seismic loading due to higher fracture energy and improved material behavior. Both dam types meet anti-sliding stability criteria, but RFC offers enhanced resilience. For engineering practice, this highlights RFC’s potential for safer, more cost-effective, and environmentally sustainable dam construction, especially in seismic regions. The findings support broader adoption of RFC in infrastructure projects and inform future seismic design standards. These advantages make RFC technology a promising alternative for modern dam engineering, particularly in seismic regions where durability and performance are critical.

We hope this Special Issue will shed light on recent advances and developments in the area of dam engineering and attract attention from the scientific community to pursue further research and studies on simulation, testing, and field measurements of dams and appurtenant structures.