Dam Operation Research Articles

A profit driven optimal scheduling of virtual power plants for peak load demand in competitive electricity markets with machine learning based forecasted generations

The operation of generating resources connected to VPPs during peak demand is crucial for determining the economic sustainability of participants in a competitive electricity market and minimizing the need for expensive peaking power plants. This paper proposes a profit driven strategy for scheduling of resources associated with VPP during peak load demand in competitive electricity market followed by different machine learning approaches for predicting the pattern of generation in DAM. The MILP has been developed by using GAMS integrated with MATLAB. The Intra-VPPs consisting TGs and DERs have been designed by using IEEE 33 bus distribution system. The performance of this system aligns with cases which investigate the interplay of EM dynamics, DERs contribution and scheduling of TGs, in order to optimize the operation of VPPs and assured the profits along with generating power amount for given time and load demand. Additionally, the generation pattern for future load in DAM operations has been forecasted using different neural network fitting models for enhancing the system's efficiency. The proposed work reduced the operating cost, nodal prices of the system followed by considerable improved profit for designed VPPs, in which more than 50 % profit driven by DERs itself of the whole system.

An intelligent method for temperature load of arch dams

Temperature load significantly affects the deformation and stress of arch dams. Traditional methods for determining temperature loads may not adapt to complex environments, such as high-altitude regions with large temperature variations. This study proposes an intelligent method for temperature load of arch dams. Based on the measured data from existing dams, a physics-informed convolutional neural network is developed, enabling direct application to newly designed dams. The intelligent method delivers annual temperature boundaries on the dam surface, aiding the finite element model in predicting deformation and stress during operational phases. Validation demonstrates accurate results for dam body temperature and deformation, aligning closely with measured data, while also pinpointing critical stress areas within the dam. This method advances the AI-assisted design by predicting temperature loads during dam operation, providing strong support for determining the most unfavorable loading without measured data and ensuring the safety of the structure.

A Weight-of-Evidence Approach for Understanding the Recovery of Okanagan Sockeye Salmon

The productivity of Pacific Sockeye salmon (Oncorhynchus nerka) in the Columbia River has been declining over the past century. Yet, the Okanagan River Sockeye salmon population, which spawns in the Okanagan River, a Canadian tributary of the Columbia River, has seen a remarkable turnaround in abundance. Different hypotheses and lines of evidence covering multiple spatial scales have been proposed to explain this recovery; but they have never been comprehensively assessed. We adopted a weight-of-evidence approach to systematically assess the relative likelihood that each of these causal hypotheses contributed to the observed recovery. Our analysis disentangles the relative consequences of a set of environmental management actions that have been implemented to augment the Sockeye salmon freshwater productivity, while accounting for changes in freshwater and marine environmental conditions. Our list of potentially explanatory causal factors (anthropogenic and natural) included: (1) changes in escapement concurrent with improving local fish passage, (2) the implementation of fish-friendly flows in the Okanagan River, (3) initiating a hatchery restocking program, (4) potential improvements to Columbia dam operations to support higher relative survival of out-migrating juvenile fish, (5) possible shifts in survival-favorable conditions in the coastal marine environment for ocean-going life stages, and (6) broader changes to multi-stock harvest regimes in the Columbia River. Our assessment leveraged comparisons with the population dynamics of another Sockeye salmon stock in the Columbia River basin to differentiate between the impacts of management actions taken within the Okanagan watershed (our focus) from those occurring over the broader basin and marine scale. The results suggest that while shifts towards survival-favorable conditions in the coastal marine environment in 2007 played an important role in the upturn of the Okanagan population, alone it cannot explain the rate at which the Okanagan River Sockeye salmon recovered. Strong evidence supports the combined effect of increased escapement in conjunction with establishing and securing fish-friendly flows during spawning, incubation, and alevin emergence. Additionally, Sockeye salmon restocking improved the resilience of the stock against density-independent mortality events. These combined basin-level management actions played a pivotal role in magnifying the recovery trajectory afforded by improved marine survivorship. The spectacular response of the Okanagan River Sockeye salmon to the holistic perspectives and management interventions of Indigenous and other caretakers provides hope that other Pacific salmon stocks can be stabilized and recovered.

Geotechnical Forensic Investigations of a Gravity Dam: Addressing Seepage and Sliding Problems in the Basalt Foundations of Karjan Dam, Gujarat, India

Geotechnical forensic engineering plays a crucial role in identifying and mitigating potential issues in large gravity dams. The Karjan Dam in Gujarat, India, a 100-meter-high gravity dam built 38 years ago on Deccan basalt, encountered significant geotechnical challenges during construction due to early investigation oversights. These oversights failed to detect sub-horizontal weathered rock seams within the basalt during the pre-construction investigations, which could have posed significant seepage and sliding risks during the dam's operation. Subsequent detailed investigations during the construction phase revealed that these seams extended throughout the foundations of the dam blocks. In-situ shear tests were conducted to determine the shear parameters, namely cohesion (C) and the angle of internal friction (ϕ) of the seams. The test results indicated low shear strength parameters, necessitating a re-evaluation of the dam's safety. Stability analysis revealed that the spillway and certain non-overflow blocks were at risk of sliding and seepage after reservoir filling. To address these geotechnical challenges, a combination of treatments—including concrete shear keys, grouting, and design enhancements—was implemented to prevent sliding and control seepage. The timely forensic investigation and treatment during the construction stage ensured the dam's safety, which has operated without issues since 1986. This study underscores the critical importance of integrating engineering and geological assessments at various stages of dam construction. Re-evaluating and addressing evolving foundation conditions, particularly during construction, is essential for applying effective treatments to prevent dam failure during operation. The findings from this case study provide valuable geotechnical insights required for enhancing the safety and resilience of dam infrastructure globally.

Integrated operation of sand dam and groundwater dam to increase water supply capacity in mountainous areas of Chuncheon, South Korea

Study regionA valley area in South Korea Study focusSand dams are cost-effective water-storage facilities for water-stressed areas in arid and semi-arid climates, with the advantages of reducing evaporation losses and filtering pollutants. Generally, sand dams are constructed by placing a horizontal barrier across the river bed, creating a naturally sand-filled structure upstream. Unlike this typical construction, a sand dam in Korea in the monsoon climate region was built near a mountainous valley, not in a stream, in Mulori, Chuncheon City, to ensure a sustainable water supply throughout the year, and especially to prevent freezing in the winter. Furthermore, a small-scale groundwater dam was additionally constructed downstream of the sand dam to increase the water supply capacity in preparation for severe droughts. In this study, the hydrological reservoir-routing simulations were performed to evaluate the effects of the combined use of the two dams on increasing water supply. New hydrological insights for the regionDaily discharge rates for the period from March 16, 2020 to July 6, 2022 were simulated for several hybrid operations that supplies water primarily through the sand dam under the normal conditions, but combines both water sources to manage severe droughts. The simulated results showed that, compared with operating the sand dam alone, the hybrid operations could satisfy the village’s water demand by increasing the minimum water supply rates by 24.6–50.0 m³/day for different simulation conditions. The combined use of sand and groundwater dams presented in this study will help provide sustainable water supply in water-stressed areas, especially mountainous uplands vulnerable to droughts and freezes.

Flooding and dam operations facilitate rapid upstream migrations of native and invasive fish species on a regulated large river

Dams commonly restrict fish movements in large rivers but can also help curtail the spread of invasive species, such as invasive bigheaded carps (Hypophthalmichthys spp). To determine how dams in the upper Mississippi River (UMR) affect large-scale invasive and native fish migrations, we tracked American paddlefish (Polyodon spathula) and bigheaded carp across > 600 river km (rkm) and 16 navigation locks and dams (LD) of the UMR during 2 years with contrasting water levels. In 2022, a low-water year, both native paddlefish and invasive bigheaded carp had low passage rates (4% and 0.6% respectively) through LD15, a movement bottleneck being studied for invasive carp control. In contrast, flooding in 2023 led to open-river conditions across multiple dams simultaneously, allowing 53% of paddlefish and 46% of bigheaded carp detected in Pool 16 to move upstream through LD15. Bigheaded carp passed upstream through LD15 rapidly (μ = 32 rkm per day) a maximum of 381 rkm, whereas paddlefish moved an average of 9 upstream rkm per day (maximum of 337 rkm). Our results can inform managers examining trade-offs between actions that enhance native fish passage or deter movements of invasive species. This understanding is critical because current climate change models project increases in flooding events like that observed during 2023.

Major recent failures in Brazilian mine waste containment facilities, current cases of maximum emergency level and imminent risk of rupture, and a brief sustainability analysis.

Wasteisthe materials left over after the processing of ores. Significant disasters involving waste disposal structures have occurred in Brazil in recent years and caused severe damage by contaminating soil, rivers and coastal areas, destroying native fauna and flora, interrupting the water supply and compromising its potability, putting the population's health, livelihoods and economy at risk, as well as causing 289 irreparable human deaths. Regulatory laws have become stricter, and since 2019, after the tailings dam tragedies occurred in 2015 and 2019 in Mariana and Brumadinho, in Minas Gerais, the operation of upstream-raised tailings dams has been prohibitedin Brazil. In 2022, a waste slide from a sterile pile at the Pau Branco Mine in Nova Lima promoted a dike overflow. There was the death of five people whose car was buried by a landslide on a hillside. New strategies and technologies, such as reprocessing and recycling, can be tested to ascertain whether they can help improve practices in tailings management. Indeed, mining companies' corporate responsibility and sustainability practices need to be evaluated toverify whether they better match expectations. On the other hand, more specific and detailed regulations and resolutions are required to ensure the safe monitoring and management of sterile waste piles. This paper presents a review of the facts, a discussion of the literature (mainly on recent tailings dam disasters), the current situation of mining-containingwaste structures in Brazil, a brief sustainability analysisand perspectives aimed at preventing/minimising catastrophes in the future.

Reservoir Operation based Machine Learning Models: Comprehensive Review for Limitations, Research Gap, and Possible Future Research Direction

The operation of dams and reservoirs is critical for water resource management, including flood control, irrigation, hydropower generation, and environmental conservation. Traditional optimization techniques like Dynamic Programming (DP), Linear Programming (LP), and Nonlinear Programming (NLP) have been foundational in managing these operations. However, they often fall short in addressing the complexities of modern water management challenges posed by climate variability and increasing water demands. Machine learning (ML) techniques have emerged as powerful tools to enhance the efficiency and accuracy of dam and reservoir operations. This paper provides a comprehensive review of various ML models, including Neural Networks, Genetic Algorithms, Decision Trees, and Ensemble Methods, highlighting their applications in predicting reservoir inflows, optimizing water release schedules, and improving flood risk management. Notably, ML models like Long Short-Term Memory (LSTM) and Convolutional Neural Networks (CNNs) have shown significant improvements in forecasting accuracy and operational decision-making. Despite these advancements, several limitations and research gaps persist, including the need for real-time data integration, adaptive learning mechanisms, and models that consider socio-economic and climatic factors. This review underscores the importance of addressing these gaps to develop more robust and generalizable ML models. Future research directions are suggested to focus on hybrid models combining ML with traditional optimization techniques, comprehensive validation across diverse conditions, and the integration of ecological and economic considerations. By systematically identifying and addressing these limitations, this research aims to pave the way for more effective and sustainable dam and reservoir management practices. Leading towards suggesting that enhancing real-time data integration and developing adaptive learning mechanisms are in order to improve model responsiveness.

Assessing the possible influence of human activities on sediment transport in the Saskatchewan River and its delta

Sediment transport is a complex, multi-dimensional process. With the advancement in computing power and sophistication of computer applications over recent decades, it has become possible to conduct detailed analysis and simulations of soil erosion and sediment transport. The primary objective of this study was to examine and predict the potential influence of human activities on sediment transport. This was achieved by analyzing sediment transport in the Saskatchewan River beneath the E.B. Campbell Dam and in the Saskatchewan River Delta. The Hydrologic Engineering Center's-River Analysis System (HEC-RAS) was deployed to ascertain the sediment transport capacity and estimate erosion, sedimentation, and riverbed changes. Cross-sectional data, flow data, and sediment data were used in conjunction with HEC-RAS. The simulation results reveal that sediment transport below the E.B. Campbell Dam is limited, leading to notable sediment erosion. The selected study area has witnessed significant erosion during high-flow periods, particularly in the event of floods. Between 2012 and 2019, the riverbed elevation at the selected survey site decreased by approximately 0.45 m. The study findings corroborate that the Saskatchewan River and its delta have been impacted by human activities. Potential erosion and deposition below the E.B. Campbell Dam have been simulated for the selected site. The aim is to provide decision-makers or related stakeholders with insight into how dam operations can be adjusted to decrease erosion while sustaining hydrological, ecological, and environmental outcomes from human activities.

A novel finite element limit equilibrium method and its application in instability analysis for 3-D high core rockfill dams

The safe operation of high rockfill dams is an important issue related to human life and property safety. However, the stability analysis of high core rockfill dams with complex spatial morphology is mostly confined to two-dimensional, and appropriate stability analysis methods are scarce. Therefore, it is necessary to develop the three-dimensional stability analysis method for high core rockfill dams and study the spatial stability mechanism after impoundment. Firstly, a finite element limit equilibrium framework suitable for stability analysis of high rockfill dams is introduced, and the horn-shaped three-dimensional failure mechanism is presented for optimization. Then, according to the statistical results of the actual core rockfill dam above 100 m, 15 high dam models with actual Duncan-Chang parameters between 100 m and 300 m are established to study the three-dimensional instability mechanism. Meanwhile, grey relation analysis (GRA) is used for quantitative analysis of stability sensitive factors. Finally, the stability analysis of the Quxue core rockfill dam (173.2 m) was completed within the established stability framework. The results show that the combined failure mechanism with the horn-shaped is suitable for dam stability analysis, and with the increase of height and slope ratio of dam, the most dangerous sliding surface evolves to shallow layer. In addition, GRA results show that slope ratio is the most sensitive parameter compared to dam height and material parameters. The practical engineering stability results of Quxue show that the research results can provide a reliable reference for the stability of the high core rockfill dam.

Sharp decline in surface water resources for agriculture and fisheries in the Lower Mekong Basin over 2000-2020

Water resources play a crucial role in the global water cycle and are affected by human activities and climate change. However, the impacts of hydropower infrastructures on the surface water extent and volume cycle are not well known. We used a multi-satellite approach to quantify the surface water storage variations over the 2000–2020 period and relate these variations to climate-induced and anthropogenic factors over the whole basin. Our results highlight that dam operations have strongly modified the water regime of the Mekong River, exhibiting a 55 % decrease in the seasonal cycle amplitude of inundation extent (from 3178 km2 to 1414 km2) and a 70 % decrease in surface water volume (from 1109 km3 to 327 km3) over 2000–2020. In the floodplains of the Lower Mekong Basin, where rice is cultivated, there has been a decline in water residence time by 30 to 50 days. The recent commissioning of big dams (2010 and 2014) has allowed us to choose 2015 as a turning point year. Results show a trend inversion in rice production, from a rise of 40 % between 2000 and 2014 to a decline of 10 % between 2015 and 2020, and a strong reduction in aquaculture growth, from +730 % between 2000 and 2014, to +53 % between 2015 and 2020. All these results show the negative impact of dams on the Mekong basin, causing a 70 % decline in surface water volumes, with major repercussions for agriculture and fisheries over the period 2000–2020. Therefore, new future projects such as the Funan Techo canal in Cambodia, scheduled to start construction at the end of 2024, will particularly affect 1300 km2 of floodplains in the lower Mekong basin, with a reduction in the amount of water received, and other areas will be subjected to flooding. The human, material and economic damage could be catastrophic.

Novel framework for quantifying dam construction, climate change, and land-use change impacts on flow regime: A case study in Ganjiang River Basin, China

Study regionThis study was conducted in the Ganjiang River Basin, situated in eastern China. Study focusPrevious studies often quantified the impacts of climate change, land use, and dam construction on flow regime by only focusing on two of these factors at one time. In addition, the previous method used to quantify the deviation in the timing of annual extreme water conditions has a flaw. Therefore, this study improved the formula for calculating the deviation in the timing of annual extreme water conditions. Moreover, we proposed a novel framework for quantifying the impacts of dam construction, climate change, and land-use change on flow regime. New hydrological insights for the regionThe study observed significant alterations in the flow regime of the Ganjiang River Basin. These modifications were predominantly influenced by dam construction and climate change. Dam construction led to a notable increase in dry season flow and minimum flow indicators, while decreasing maximum flow indicators. Conversely, climate change resulted in a reduction of minimum flow indicators and an increase in maximum flow indicators. Climate change has also led to an increase in the frequency and duration of flow pulses. Intriguingly, dam construction and climate change played offsetting roles for 77 % of the indicators. Considering the global climate change context, judicious dam operation could to mitigate the impact of climate change on the flow regime.

Spatiotemporal pattern of water age in Dongting Lake before and after the operation of the Three Gorges Project

Study regionDongting Lake Basin of China. Study focusDongting Lake is the first large-scale interconnected river–lake systems in the middle-lower reaches of the Yangtze River and the second-largest freshwater lake in China. Dam operation on the upper reaches of the Yangtze River dramatically affected the hydrological condition of Dongting Lake. Therefore, this study established a hydrodynamic-water age model to assess the effects of the Three Gorges Dam (TGD) on the spatiotemporal pattern of water age in Dongting Lake. New hydrological insightsThe results show a significant spatial and temporal variation of water age in Dongting Lake. Water age in the floodway is lower than that in the shoal, meanwhile, water age in spring and summer is lower than that in autumn and winter. By establishing a hydrodynamic-water age model, several factors influencing water age in Dongting Lake were analyzed, i.e., the influences of the Jingjiang Three Outlets' triage from the Yangtze River, the water level of the mainstream of the Yangtze River, and the flow pattern. The TGD could influence the water age in Dongting Lake by altering the hydrodynamic conditions of the Yangtze River. Results from this study provide support for flood control and dispatch management of Dongting Lake and provides a reference for water exchange studies in other large shallow lakes.

Development of modified fuzzy FMEA method in environmental risk assessment of earth dams

The investigations have shown that the construction of the dam and its related facilities have significant physical–chemical and ecological effects on the ecosystem. Failure Mode and Effects Analysis (FMEA) is a technique for ranking risks in projects to construct dams, but it has many deficiencies and ambiguities. Therefore, to prevent the shortcomings of the classical method, the modified fuzzy inference system (MFIS-FMEA) method has been used by creating a two-stage model to more accurately assess the risk of Eyvashan Dam. First, all the considered indicators are weighted using the Shannon entropy method, and the environmental risk is prioritized using the Fuzzy OWA method. In this study, two-stage fuzzy reasoning and a Max–Min combination rule are used. When severity (SEV) and occurrence (OCC) variables are combined, the critical risk index (RCI) values are predicted in the first stage. RCI and detection index (DET) input are then used to predict the MFIS-RPN in the second stage. The results of the risk priority number (RPN) in the MFIS-RPN method are much more accurate and serious than the FIS-RPN method due to the two-stage nature and the use of new language terms. The results of the proposed MFIS-RPN technique show that the highest RPN was obtained with immediate action in the dam construction phase for soil erosion and soil pollution and in the dam operation phase for aquatic and water pollution. Therefore, due to the increase in risk score, it is necessary to take immediate and more accurate monitoring during the construction and operation phases.

Scenario-Based Modeling on Chlorophyll-a in Uiam Reservoir of Korea According to Variation of Dam Discharge

This study analyzes quantitative algae mitigation, using chlorophyll-a as an indicator, through waterbody management techniques such as pulses released from upstream dams, employing a three-dimensional numerical model. Numerical simulations focused on algae reduction through dam operations by investigating nine scenarios based on Chuncheon Dam, Soyang Dam, and Uiam Dam, located in the upper and lower reaches of Uiam Reservoir of Korea. These scenarios, aligned with actual dam operation manuals, aimed to differentiate the impact of each dam’s operation by decreasing water residence time for Uiam Reservoir. The Uiam Reservoir, smaller than the upstream Chuncheon Dam and Soyang River Dam, is significantly influenced by their discharge rates. During summer, temperature differences exceeding 7 °C between discharges from Chuncheon Dam and Soyang Dam inflowed into the right side and the left side, respectively, of the reservoir, leading to poor mixing, which was further hindered by islands within the reservoir. Consequently, due to the influence of the different base water temperatures of the Bukhan River and Soyang River and the topographical characteristics, the impact range varied depending on the operation of each dam, and the amount of algae mitigation differed at each point. In emergency situations where algae blooms proliferate rapidly, appropriate dam operations in water bodies with large dams upstream and downstream, like Uiam Reservoir, can be effective in mitigating algae at specific regions of the reservoir.

How economically and environmentally viable are multiple dams in the upper Cauvery Basin, India? A hydro-economic analysis using a landscape-based hydrological model

Abstract. The construction of dams threatens the health of watershed ecosystems. The purpose of this study is to show how multiple dams in a basin can impact hydrological flow regimes and subsequently aquatic ecosystems that depend on river flows. The approach assesses the ecosystem services (ESs), including the tradeoffs between economic and ecological services due to altered flow regimes. It uses a previously developed model that integrates a landscape-based hydrological model with a reservoir operations model on a basin scale. The approach is novel because not only does it offer the analysis of alterations in ecosystem services on a daily scale when pre-dam data are unavailable but also allows for dams to be synthetically placed anywhere in the river network and the corresponding alterations in flow regimes to be simulated in a flexible manner. As a proof of concept, we analyse the economic and ecological performances of different spatial configuration of existing reservoirs instead of synthetically placed reservoirs in the upper Cauvery River basin in India. Such a study is timely and conducted for the first time, especially in light of calls to assess the cascade of reservoirs in India and regions elsewhere where pre-dam data are unavailable. The hydrological impact of different configurations of reservoirs is quantified using indicators of hydrologic alteration (IHAs). Additionally, the production of two major ecosystem services that depend on the flow regime of the river, as indicated by irrigated agricultural production and the normalized fish diversity index (NFDI), is estimated, and a tradeoff curve, i.e. a production possibility frontier, for the two services is established. Through the lens of the indices chosen for the ecosystem services, the results show that smaller reservoirs on lower-order streams are better for the basin economy and the environment than larger reservoirs. Cultivating irrigated crops of higher value can maximize the value of stored water and, with lower storage, generate a better economic value than cultivating lower-value crops while reducing hydrological alterations. The proposed approach, especially when simulating synthetic spatial configurations of reservoirs, can help water and river basin managers to understand the provision of ecosystem services in hydrologically altered basins, optimize dam operations, or even prioritize dam removals with a goal of achieving a balanced provision of ecosystem services.

Coagulation tests of waste pulp from copper mineral processing

The sustainable use of water in mineral processing is essential for maintaining the ecosystem that supports the mining environment and, consequently, for the operation itself that uses water resources. As an area that has such a finite resource as a basic operating condition and that uses this resource on a large scale, it is necessary to constantly seek to optimize its use, having as pillars quality and economy in the treatment of effluents generated. It is in stages like this that coagulating reagent work. In the processing unit in question, more than 90% of the water is recirculated and reused, a process that relies on the support of a coagulant to accelerate the sedimentation of solids and guarantee the reuse of water of sufficient quality to provide operations with the solvent necessary for the environment. physicochemical. The coagulant currently used in tailings dam operations is aluminum sulfate. Due to the high use and cost spent on this reagent, tests were conducted with two other alternative coagulants (iron III chloride and iron III sulfate), comparing the cost-benefit between the reagents assessed. To this end, a cost-benefit factor was used, calculated using the cost of the reagent, dosage, residual turbidity of the clarified liquid and the sedimentation speed of the solids. After the tests, it was found that aluminum sulfate, the reagent used in the operation until then, was the best option among the reagents assessed. However, a reduction of 21.43% in the dosage currently used of this reagent by the company, maintaining the final turbidity target is possible, thus generating cost reduction.

Economic life evaluation of reservoir dams based on comprehensive costs and benefits analysis considering potential dam breach: A case study of the Luhun reservoir in China

The scientific evaluation of a dam’s economic life is necessary to determine its management strategy rationally. However, most studies have mainly focused on analyzing the current economic characteristics of reservoir dams without considering their long-term development trend. And they have failed to incorporate the potential loss caused by dam breaches as one of the operating costs for dams. Consequently, this results in the inability to scientifically calculate the economic life of reservoir dam operations. Therefore, this study analyzed the factors influencing the economic life of reservoir dams in term of safety, costs, benefits and society, and established an economic life evaluation indicator system for reservoir dams. Based on the analyses of costs and benefits of reservoir dams, an economic life evaluation model for reservoir dams was constructed by comprehensively considering the impact of potential dam breaches and the social impact of reservoir dams on the production and lives of local residents. Moreover, based on economic theory, the economics of various types of management measures for reservoir dams and their impact on the economic life of dams were analyzed. The proposed model was applied to the Luhun Reservoir in Henan Province, China, to quantify the comprehensive costs and benefits of its operation for each year after 1990 s, analyze the trend of its “cost-benefit” relationship, and calculate its expected economic life. The results showed that when considering its own risks and social impacts, the expected economic life of the Luhun Reservoir was 74 years. The Luhun Reservoir is expected to operate up to its non-economic life span till 2039. Finally, suggestions for expanding the economic life of dams were proposed. Potential dam breach losses can significantly reduce the economic life of reservoir dams. And risk management measures for reservoir dams should be particularly strengthened during daily operations and management.

Water Dams: From Ancient to Present Times and into the Future

Since ancient times, dams have been built to store water, control rivers, and irrigate agricultural land to meet human needs. By the end of the 19th century, hydroelectric power stations arose and extended the purposes of dams. Today, dams can be seen as part of the renewable energy supply infrastructure. The word dam comes from French and is defined in dictionaries using words like strange, dike, and obstacle. In other words, a dam is a structure that stores water and directs it to the desired location, with a dam being built in front of river valleys. Dams built on rivers serve various purposes such as the supply of drinking water, agricultural irrigation, flood control, the supply of industrial water, power generation, recreation, the movement control of solids, and fisheries. Dams can also be built in a catchment area to capture and store the rainwater in arid and semi-arid areas. Dams can be built from concrete or natural materials such as earth and rock. There are various types of dams: embankment dams (earth-fill dams, rock-fill dams, and rock-fill dams with concrete faces) and rigid dams (gravity dams, rolled compacted concrete dams, arch dams, and buttress dams). A gravity dam is a straight wall of stone masonry or earthen material that can withstand the full force of the water pressure. In other words, the pressure of the water transfers the vertical compressive forces and horizontal shear forces to the foundations beneath the dam. The strength of a gravity dam ultimately depends on its weight and the strength of its foundations. Most dams built in ancient times were constructed as gravity dams. An arch dam, on the other hand, has a convex curved surface that faces the water. The forces generated by the water pressure are transferred to the sides of the structure by horizontal lines. The horizontal, normal, and shear forces resist the weight at the edges. When viewed in a horizontal section, an arch dam has a curved shape. This type of dam can also resist water pressure due to its particular shape that allows the transfer of the forces generated by the stored water to the rock foundations. This article takes a detailed look at hydraulic engineering in dams over the millennia. Lessons should be learned from the successful and unsuccessful applications and operations of dams. Water resource managers, policymakers, and stakeholders can use these lessons to achieve sustainable development goals in times of climate change and water crisis.

Compliance of Haditha Dam in Iraq to the International Standards for Surveillance and Monitoring

Dams are mega structures that retain huge volumes of water and their safety is important to national security, economy, and public interest. In this study, the types of regular measurements with their recorded value for Haditha Dam were checked for compliance with the standard international surveillance and monitoring procedures such as the procedures of the International Commission on Large Dams (ICOLD), the United States Bureau of Reclamation (USBR)and other to ensure safe dam operation and to avoid the scenario of the Derna Dam break, in Libya that occurred in September 2023. The result shows that the highest recorded settlement was found at station 41 on the left side of the dam body exceeding the design criteria (219 mm) by about 51 %, the frequency of measurement does not comply with the required international standards. There are 7 cells of pore pressure that exceeded the design criteria and the greatest percentage of exceedance was 21.57 % was found at pore pressure number 995. For piezometer reading, the percentage exceedance was 9.1% and it was found on the left side at piezometers number 58-8. The highest percentage of movement 62 % was found at join meter device number D18. The recorded seepage rate through the dam was found within the permitted limits. The visual inspection followed at Haditha Dam was not according to the standard required inspection.