World Environmental and Water Resources Congress 2019: Hydraulics, Waterways, and Water Distribution Systems Analysis

As the development of Chinese Ecological City, the demand of weirs becomes more and more seriously, not only to facilitate general functions such as shipping, irrigation, flood discharge, but also provides harmonious with environment, ecological waterscape. Several new types steel structure moveable dam emerges and spreads in China along with rubber dam gradually are replaced for its vulnerable of bags, unable to promptly discharge flood, poor landscape effect, etc. This paper briefs origins and development in engineering application of 5 new steel structure moveable dam, including: horizontal sluice gate, pneumatic shield dam, steel dam gate, hydraulic lifting dam, hydraulic elevator dam, furthermore it explains how these dam works and its structure characteristics through diagram. Finally, through comparison of foundation requirement, civil works quantity, installation difference, operation, ecological waterscape, shortcomings, and cost analysis. The paper summarizes and analyzes the applicable and inapplicable river way conditions for aforesaid 5 new steel structure dam and provides professional knowledge background for application of steel structure dam.

The Lower St. Johns River Estuary in Florida has experienced both urban and exurban development along its banks over the course of many decades. The extent of salinity intrusion into the estuary is controlled by a combination of factors which may be altered through natural or anthropogenic forces. To better understand the factors controlling salinity intrusion, the environmental fluid dynamics code plus (EFDC+) was applied to model the hydrodynamics of the estuary. This study discusses the calibration and validation of the model, analysis of the extent of salinity intrusion, and application of habitat analysis using the EFDC_Explorer modeling system (EEMS). The results of this study showed that the extent of salinity intrusion in the LSJR estuary is primarily controlled through varying combinations of upstream flow, long-term variations in the open ocean, and wind drag. Results of the habitat analysis concerning submerged aquatic vegetation and wetlands constitute a baseline for comparison with alternative management and future change scenarios for the basin.

Little Calumet River–Hart Ditch River system in Northwest Indiana had a historic flood during Ike Storm in 2008. Little Calumet River Commission (LCRC) maintains the system now. Several improvements were made after this flood which also includes a levee system in the Indiana region. In this system, north flowing Hart Ditch confluences with the east-west flowing Little Calumet River System. Large storages were made in the eastern side for accommodating the flood flow. But the natural flow is more towards the western arm in the Little Calumet River. To divert more water towards east, a high flow channel was built recently near the Hart Ditch confluence point. To assess the benefits of this channel, a sequence of HEC HMS and HEC RAS models were developed and calibrated. With prior condition and the new condition, HEC RAS model was simulated and the usefulness of the high flow channel was evaluated for recent storms and the 2008 storm. This analysis indicates that after the high flow channel was constructed, 40 to 50% of the flow goes towards east during high flows. Low flows of Hart Ditch normally goes towards west even after this high flow channel.

All reservoirs are subjected to sedimentation, which disallows to meet the growing needs that reservoirs are intended to serve. Lack of regular and less cumbersome techniques for assessment of sedimentation levels and available capacity poses a challenge for the sustainable management of reservoirs. This study assessed the reservoir sedimentation levels and storage capacity from 2000 to 2018 using remotely sensed data for Namadope Reservoir in Luuka District in Uganda. A methodology to determine the reservoir capacity using a power relationship between remotely sensed surface areas and storage capacities of the reservoir is presented. The loss in reservoir capacity due to sediments increase for 18 years was found as 65,058 m³, making a sedimentation rate 3,614.3 m³/year. The agreement between measured and the remotely sensed reservoir volumes satisfactorily showed that the relationship can be used for assessment of the reservoirs in the catchment area.

Nature-like fishpasses have been installed at many migration barriers in recent years to mitigate the effects of human development and habitat fragmentation on fish. The design of these fishpasses determines the flow characteristics and ultimately the success of these passage facilities. In recent years, research in the use of computational fluid dynamics (CFD) models for assessing flow in fish habitat structures and fishpasses has increased tremendously. This particular research study used a three-dimensional computational fluid dynamics solver, ANSYS-CFX, to model the flow field through the rock-weir type nature-like fishpasses. The CFD simulations were tested using experimental observations. This study numerically investigated the longitudinal water surface profiles and velocity profiles of rock-weir fishpasses for different structure geometries (weir configurations, arm angle, pool spacing) and channel characteristics (bed slope and flow rate). The simulated water surface profiles for each structure geometry along the channel center plane confirmed three flow regimes: (1) weir, (2) transitional, and (3) streaming. It is hoped that the results of this study will advance our knowledge on flow in a rock-weir fish pass and be useful to fish pass designers and fish biologists.

The water and sediment entering the Lower Yellow River (LYR) have varied dramatically causing a significant adjustment in the channel planform, typically, in the wandering reach downstream of the Xiaolangdi Dam. To evaluate the response of the confined channel-floodplain system of the LYR to the dramatic change in the water and sediment input, this study presents a detailed investigation of the relationship between the channel planform adjustment and the water-sediment change based on field measurements. The channel sinuosity was determined to increase from 1.15 to 1.25, while the radius of curvature decreased to 2.96 km, approximately 17~41% of the counterpart in 1999. The sandy bar area in the channel increased after 1999, while the number of channel bars remained almost unchanged and the braided index decreased from 3.16 to 2.41. All of these changes in the channel planform indicate that the wandering reach of the LYR from Jiahetan to Gaocun generally behaves like a meandering river since 1999. In particular, there has been an increase in the channel sinuosity, a decrease in the channel bar area, and a decrease in the number of branched channels. Furthermore, this study argues that the adjustment in the channel pattern of the LYR is closely related to the ratio of the minimum energy slope to the channel slope. A larger value of the ratio corresponds to a more wandering channel, a much shallower and wider cross-section, and a much smaller channel sinuosity.

In the 1980s the International Joint Commission listed Lower Green Bay and the Fox River as an area of concern because of problems due to contaminated sediment, poor water quality, and lost or altered habitat, and subsequently the USEPA designated Lower Green Bay as a Superfund National Priority site. The authors have studied the circulation, thermal regime, and water quality in Green Bay, using models based on the Princeton ocean model (POM) and the environmental fluid dynamics code (EFDC). Obstacles in those studies included shortage of field measurements and model limitations. Modeling challenges included the creation of boundary conditions for nested models, use of structured grids, modeling stratified flows in shallow areas, and limited model documentation. Currently NOAA GLERL is migrating its models to the finite volume community model (FVCOM) a state-of-the-art modeling platform. The model under development in this study is based on FVCOM to overcome the challenges mentioned above, facilitate research collaboration, and will provide a single and wider platform to investigate surface waves, lake turbulence, 3-D sediment transport, and water quality in Lake Michigan, and Green Bay in particular. The FVCOM model runs in parallel mode, with notable advantages in computational efficiency. Other advantages of the new model are the use of a single unstructured grid for Lake Michigan and Green Bay, with fine density in the bay and a coarser grid in the lake, and the availability of a menu of turbulence closure models that can help in the simulation of stratified flows.

Recently, South Korea has been increasingly experiencing large changes in precipitation patterns, in particular, a storm may transition from a mild to a torrential rainfall within a few hours, which may ignite extreme urban flood inundation. This urban flood inundation is increased mainly by changing landcover, which is characterized by an increase of impervious cover across urban and sub-urban areas. This study evaluates a volume of the urban flood resulting from a manhole overflow in the stormsewer systems in the city of Andong, South Korea, under changing landcover conditions. Due to lack of data, this model still shows challenges to incorporate flooding of those subwatersheds that are not routed to the stormsewer network. Simulations are conducted using EPA SWMM, which is a widely used program for modeling urban flood inundation. The simulation is performed using synthesized rainfall derived from intensity-duration-frequency curves of Andong City for different imperviousness scenarios. The results indicate an increase in about 5% flood volume when imperviousness increased from 20% to 80%. Numerical experiments also reveal that combining 1D-SWMM model with spatial analysis in GIS environment allow to analyze urban flood with the limited input dataset. This study is also expected to be a backbone of the upcoming application research/projects in South Korea to address urban flood inundation issues induced by torrential rainfall occurrences.

The flux of fluctuation energy for collisional particles, which plays an important role in bounded granular flows, was investigated based on the kinetic theory for granular flows. In order to determine the fluctuation energy during collisions between solid walls and particles experiencing apparent shears, a second-order approximation solution to the Boltzmann equation to determine the velocity distribution function of particles was used, which makes it possible for us to discuss how a shear rate affects the fluctuation energy flux in bounded granular flows. Comparisons with numerical simulations and previous theories were presented, which shows that the predicted fluctuation energy flux and simulation results are in well agreement under different conditions.

Rapid filling flows in stormwater systems during rain events has been cause of diverse operational problems and as result this has been investigated by a significant group of researchers to date. Frequently in these studies, a variety of numerical modeling tools has been applied while trying to understand these unsteady, two-phase flow conditions. A wide variety of modeling strategies has been created to date and, associated with this models, various mathematical formulations were proposed to describe such flows. These range from a simple system of ordinary differential equations, passing through systems of one-dimensional partial differential equations, all the way into Navier-Stokes equations associated with a free surface flow tracking algorithm. There has been limited discussion on the merits, advantages, and limitations of each approach. This manuscript provides a preliminary survey of alternatives to represent unsteady, two-phase flows in urban water systems, with a focus here in one-dimensional formulations. This is a part of a concerted effort of the EWRI Task Committee on Unsteady Two-phase Flows in Urban Water Systems to provide designers with better guidelines to include in their projects the effects of air in the hydraulics of these water systems.

A novel paradigm of risk study for bridge infrastructure is proposed and illustrated. The paradigm addresses two observations about the nature of risk that have not been sufficiently absorbed by current approaches: (1) risk issues are intrinsically different over physiographic regions, and (2) risk derivation should be integrated with the study of resilience. Through the use of one of the multi expert-multiple criteria decision making techniques with derived failure modes, the proposed paradigm addresses risks of intrinsic instability, human intervention, and flood exceedance within unique physiographic environment. Thirty-five bridges for which a stream gauge on or near the bridge recorded the flow during collapse are investigated. The paper is offered as a stimulus to think about the possible existence of a unified paradigm that can span the various spheres of interest of risk study, and as a specific proposal for the possible nature and scope of such a paradigm.

A geyser at vertical shafts in stormwater and combined sewer systems is characterized by a weak initial eruption of a mixture of gas and liquid followed by a few strong consecutive eruptions within a time frame of a few seconds. Field-scale geysers may have eruption heights exceeding 30 m and may cause operational problems and deleterious effects in these systems. The present work presents the derivation for the upper limit velocity of a gas-liquid mixture eruption at vertical shafts. The mathematical analysis shows that the maximum velocity of a gas-liquid mixture eruption is the sound speed of the gas-liquid mixture. The derived upper limit for the geyser eruption velocity is assessed using two test cases: a geyser event in a stormwater collection system in Minneapolis and our laboratory experiments. The results show that the gas-liquid mixture sound speed is a good estimator for the upper limit of the maximum geyser eruption velocity in stormwater and combined sewer systems.

In Ecuador, steep rough-bedded channels constitute the main component of mountainous drainage system. They provide sediment to milder-slope downstream channels. Thus, sediment transport represents a driving process in natural drainage system. Namely, it defines river morphology evolution. To quantify and to understand the magnitude and effect of this process in the surrounding environment, the understanding and knowledge of bedload transport must be improved. The study of sediment transport in steeper channels with coarser material is a complex process. The continuously changing environment results in a high uncertainty in the quantification of sediment transport rates. Some equations have been proposed to quantify the rates. However the lack of actual measured data does not allow proper quantification and verification. On the other hand, hydraulic geometry (HG) theory has been applied to generate elements for a consistent monitoring of rivers behavior. Dimensionless HG relations that replicate what is observed in rivers have been obtained. Parameters such as top width, mean flow depth, mean velocity, and suspended sediment load of several gravel-bed rivers have been related with liquid discharge. The present study proposes the characterization of bedload sediment transport of steep gravel-bed rivers in terms of dimensionless HG relations. Measurements in various reaches along a river of bedload transport rate are performed to determine the parameters (exponents and coefficients) of the HG relations. The results represent a contribution that allows the reduction of the lack of field-measured data as well as the application of a theory generally used to characterize hydraulic-geometric parameters to characterize bedload sediment transport.

This study investigates 3D numerical simulation of open channel flow in a junction in the presence of a pit in its vicinity. A laboratory channel setup is considered for the present study. CFD software Fluent is used to simulate the 3D flow field. The numerical model is validated by comparing the simulated results for junction flow without a pit with the experimental results available in literature. In addition, simulations are performed for junction flow in the presence of a pit. Different locations of the pit are considered. Results for velocity field, water surface profile, flow separation zone, and energy loss are presented. Length and width of separation zone are reduced in the presence of the pit. Flow structure in the junction is most influenced when the pit is located at the junction. Lateral currents present at the downstream cross-sections and increased velocity past the forward step of the pit cause decrease of the spatial extent of the separation zone. Flow reversal occurs due to interaction of the high velocity and forward-facing step of the pit post channel junction. Energy loss is more in the presence of the pit. Pit location has no effect on energy loss. Strong upwelling flow reduces the water depression post junction section for the downstream pit location.

The coastal area of the Ganges Delta in Bangladesh is characterized by tides and salinity from the Bay of Bengal. Salinities in the Bangladesh coast are dependent on the annual rainfall, evaporation, freshwater flows discharging from upstream and the impact of climate change. Average salinity concentrations at the coast are higher in the dry season than in the monsoon, due to reduction in freshwater flow from the upstream. The higher salinity levels have adverse impacts on agriculture, aquaculture, domestic, and industrial water use and so on. Hence, the simulation of the calibrated salinity model has been carried out in this study to investigate the baseline condition of salinity and assessment of hydrodynamic condition which will reduce the salinity level at downstream portion of Southwest region of Bangladesh. Historical data and field measurements on salinity, water flow, water level, and numerical modeling technique have been applied to develop the hydrodynamic scenarios (mainly based on upstream discharge condition), which are simulated with the calibrated and validated hydrodynamic and salinity model. The scenario with increase in upstream flow through Ganges connected rivers has been simulated to identify the saline free zone at the most south end zone. The simulation of the calibrated salinity model has been carried out by limiting salinity level (< 1 ppt) with improved flow scenarios by mathematical modeling technique. The saline free zone with different flow scenarios has been assessed by MIKE One-Dimensional (MIKE 11) and MIKE Two-Dimensional (MIKE 21FM) Modelling system.

Urmia Lake, hyper saline lake in northwest of Iran, is a terminal basin, and its salinity depends on the water balance. The lake has been shrinking in recent decades, that cause challenges to economy and environment of the region. It is important to find the major contributors to this disaster. At the distance between the last hydrometric station and the lake, there are two buffer zones where losses and yields can affect the final amount of flow reaching to the lake. In this study, the methods of determining each of the parameters in the water balance equation have been described. The term of V_{buffer zones} in water balance equation of Urmia Lake is a collection of unmeasured positive and negative terms. The results reveal that the evaporation has the highest effect among other parameters on the monthly and annual scale, in estimating the final value of V_{buffer zones}. The accumulation input of rivers into the lake can also affect the V_{buffer zones} during wet months. Considering the monthly variations of rivers input, annual amount of V_{buffer zones} is not a good indicator to study the monthly variation of the lake water level. Therefore, the time scale has an effective role in the estimated value of V_{buffer zones}, so smaller time scale (monthly or daily) is recommended.

The South Florida Water Management District recently launched the canal capacity study to improve water management in South Florida. Since the authorization of the Central and Southern Florida Project in 1948, urbanization and land development have significantly changed the design conditions. As a result, the original plans are no longer adequate to satisfy the desired level of service. Typically, one- and two-dimensional modeling tools can be adequately used to calibrate, validate, and evaluate canal conveyance capacity based on the geometric information and canal bottom roughness. However, other open channel hydraulic conditions such as canal confluence, channel bend, bridge piers, and other hydraulic structures may also have significant influence on the conveyance capacity. Estimation of localized head losses incurred from these hydraulic conditions requires the use of advanced modeling. In this paper, a three-dimensional CFD model was developed to investigate the effects of a junction on open channel flow characteristics as a case study. CFD model implemented herein is based on solving three-dimensional Reynolds-Averaged Navier-Stokes equations using the κ-ɛ turbulence model closure. It can provide accurate and detailed flow physics including three-dimensional flow fields, pressures, and water surface elevations. The CFD model was first validated using high quality experimental data of a 90-degree junction flow under two flow conditions. Upon good agreement between model simulation and experimental measurements, the same approach was applied to the C1 canal and C1N canal junction located in the C-1 basin in South Florida. The CFD estimated head loss is intended to be incorporated into existing one/two-dimensional hydrodynamic models as a target function to calibrate the models and optimize the canal capacity for larger scale hydraulic planning problem. This study introduces a feasible approach to apply CFD and hydrodynamic models to resolve canal capacity problems which require very complicated localized hydraulic loss estimation.

The accelerated sedimentation of the main Peruvian reservoirs has caused losses of the useful storage capacity that significantly affects the water allocation to the different users. This research aims to evaluate the sedimentation risk of Palo Redondo Reservoir of the Chavimochic hydraulic system, located in La Libertad region of Peru's northern, proposing alternatives to reduce its impacts. The reservoir was designed for a total capacity of 400 MCM, however, it is likely that in the future it has an accelerated sedimentation problem due to the high erosion of the Santa River Basin and because of its water uptake system whose sand trap has an efficiency less than 75%. The methodology includes the modeling for the prediction of stream flow and sediment yield in the Tablachaca sub-basin which is a critical drainage area of the Santa River Basin, using the soil and water assessment tool (SWAT). Likewise, it includes the modeling of sediment yield in the Palo Redondo small sub-basin using the kinematic runoff and erosion model (KINEROS). It could be activated during the occurrence of the El Niño phenomenon causing maximum discharges with high rates of sediment transport to the reservoir. The SWAT calibration results show a good model performance with NASH coefficients greater than 0.6 for flow rates and sediment concentrations, respectively. On the other hand, the land cover change in Tablachaca sub-basin shows a significant reduction in erosion rates and, therefore, a significant reduction of sediments towards the Palo Redondo Reservoir.

The South Florida Water Management District (SFWMD) operates and maintains a regional water management system that consists of levees, reservoirs, and approximately 2,000 miles of canals along with their water control structures. Many of these canals and hydraulic structures were designed and constructed over 50 years ago by the U.S. Army Corps of Engineers as part of the Central and Southern Florida (C&SF) Project. Over time, the system has been deteriorating and, consequently, some canal reaches are unable to convey current design or regulatory discharges with an acceptable amount of freeboard. In some cases, a canal reach may not even be able to convey its original design discharges due to siltation or other conveyance restrictions. In order to understand the current state of the C&SF canals in regard to both original and current design requirements, the SFWMD has embarked on a new canal conveyance evaluation program (CCEP) in which canal capacities will be evaluated in regard to their original design flows, current design, or regulatory requirements, design water surface profiles, and available freeboard. For each C&SF canal, the intent of the CCEP is to use hydraulic models to assess the current conveyance capacity of the canal, evaluate the potential loss of its conveyance capacity relative to its design criteria, and in some cases develop cost-effective capacity improvement strategies. An application of the CCEP to the C-1W canal in southern Miami-Dade County, Florida, is presented as a case study.

This paper presents a simple but efficient bed interpolation algorithm based on fast sorting. In the proposed algorithm, at first the fast sort method is applied smartly on a decomposition grid to mark and group the interpolation database and the interpolating mesh into finite number of rectangle cells efficiently. Then the interpolation calculations are carried out locally for the interpolating mesh nodes and the interpolation database within the same decomposition cell. The proposed algorithm is simple and easy to be implemented on both CPU and GPU. An example case is used to demonstrate its efficiency by comparing with the classical KD-Tree searching algorithm. The testing results have shown that the computing efficiency of the CPU version is comparable to the KD-Tree method, while the GPU parallel version demonstrated the fastest performances.

Meander bends are rarely symmetric in the streamwise direction. Instead, they tend to show a preferred skewing, with the apex either pointing upstream (upstream-skewed) or downstream (downstream-skewed). There are theoretical reasons for both planform morphologies, and both can be seen in the field. Here we focus on skewing in cutoffs versus skewing in the main channel bends, and consider reaches that generally display neck cutoffs rather than chute cutoffs. In order to avoid the effects of human interference, we have selected five natural reaches, from various places around the world, which are in remote locations with negligible engineering works. We use Landsat images and Google Earth Pro to extract planform data for our study reaches. In total, 936 channel bends and 144 cutoffs have been evaluated. The percentage upstream skewed (PUS) among bends and cutoffs is estimated as 50.8% and 84.4%, respectively. The results indicate that while upstream- and downstream-skewed bends are found with nearly equal frequency in freely meandering channels, single-bend cutoff loops are strongly biased toward upstream-skewing.

In woody areas where traditional construction materials are not available engineered log jams (ELJ) may constitute a potential solution for controlling riverbank erosion. Two ELJ groyne fields formed by four structures were placed in a 12 m long rectangular flume. In the first setup, groynes had a 46% permeability whereas in the second setup, groynes had a 26% permeability. Sediment in suspension was incorporated at a constant rate after flow was stabilized. Tests showed that when groyne permeability has higher, maximum scour depth at the inner end of the groyne diminished while sediment deposition between groynes increased. This result indicates that use of the main resource for building ELJ groynes can be optimized. As the configuration of the groynes was basically idealized as a frame of cylindrical elements, results of this experimental program may also be used to design groynes made up of artificial materials resembling ELJs. This type of solution could be used where traditional construction materials are not readily available.

The Yellow River estuary is characterized by the accumulation of weak tidal and multi-sediment, frequent swinging, and rapid land-making. With the development of regional economy, it is important to ensure the basic stability and prolong the current Qingshuigou Channel in the Yellow River estuary. In addition, there are frequent swinging river channels in the mouth reaches below Cha-2, which can transfer the runoff sand to both sides of the mouth and delay the extension of the sand mouth, which is more beneficial to the stable flow path. Based on the measured data of remote sensing satellite, runoff sediment, and ocean dynamic process in the Yellow River estuary, this paper analyzes the evolution characteristics of the water channel in the mouth reach, and reveals the influencing factors and the dynamic process of the different type channels. The dynamic conditions of different type channels and their effects on the water level and the change of scour and deposition in the Yellow River's tail river are expounded. After entering the middle in the Qingshuigou flow road, the water branches widely distributed on the area of mouth reach. The diversion of these branches is advantageous to the Yellow River sediment distribution to the two sides of the sand mouth, and can prevent the rapid siltation of the sand mouth. But these branches are not conducive to the concentration of water flow flushing the main channel. Especially in the case of water and sand unfavorable, the channel may produce siltation and blockage, resulting of the river level elevation and the flood disaster in the tail channel of the Yellow River estuary. Therefore, to carry out the diversion of water channels is suitable based on the evolution characteristics of main and branch channels in the Yellow River estuary.

Sediment is one of the major contributing factors that affect the river morphology of the United States. During the construction of hydraulic structures like a dam, irrigation channel, or even to utilize the stream for navigation purpose, one of the major concerns for the design engineer would be the characteristics of sediment transported within reach. Maumee River serves for navigation purpose, and the riverbed aggradation resulting in shallow depth may affect its use. Thus, the study of sediment flow and the river bed characteristics is essential to mitigate the problems arising due to the changes in river morphology. The river reach is selected based upon available gauged station and proximity of the settlement. In this study, the Hydrologic Engineering Center's-River Analysis System (HEC-RAS) was used to develop a hydraulic analysis of the sediment transport model. The geometric data were generated from 10-meter x 10-meter resolution digital elevation model using HEC-GeoRAS extension in ArcGIS. Calibration and validation of this model were done by applying various sediment transport functions and Manning's roughness coefficient. The model output indicates the bed change pattern as well as the parts of a river reach that conform to erosion or deposition. The output of the model combined with local knowledge can help to attenuate the problem arising due to the sediment.

Three-dimensional (3D) hydraulic modelling has not been used widely in hydraulic engineering. A primary reason is that such modelling is labor-intensive and demands high computing resources. A bottleneck is the need of a 3D mesh that can be difficult to generate; in particular a poor quality mesh may degrade the model stability and accuracy. In this study, we report a research effort seeking to develop a 3D model for practical uses. A new 3D mesh, the smooth-bed Z mesh (SBZM), is developed and verified. SBZM is in contrast with two other commonly used mesh options: the sigma mesh and the staircase Z mesh. The advantages and disadvantages of the sigma and staircase Z meshes are widely known. SBZM retains the advantages of both meshes while minimizes the drawbacks. A laboratory case is used to demonstrate the SBZM approach. Comparisons are also made with the sigma and staircase Z meshes to shed light on the differences in model results.

The contribution of mainstream flow and helix flow to the pool-bar complexes in meander channel are still poorly understood. A flume experiment was conducted to study the 3D turbulent flow and pool-bar complexes in a meandering flume, whose centerline follows a sine-generated curve with a deflection angle of 110 degrees. The flume bed was composed of bulk sediment with grain sizes 1–7 mm. An acoustic doppler velocimeter (ADV) was used to measure the 3D turbulent flow field in the flume under flat-bed and eroded bed conditions, especially in the near-bed region. Detailed image data showed that, the mainstream flow initiated the erosion in curved channel, both in sections upstream and downstream the apex. During the initial stage of point-bar forming, particles eroded from the convex bank primarily transport along the same-side bank. When the two erosion areas in the convex-side merge into a larger one, sediment deposited at the convex-side point bar comes from both banks. The results indicate that the growth of point-bar is affected by both main flow and the transverse circulation. This study improves our understanding of the forming mechanics of the pool-bar complexes.

Excavation of sediment from alluvial channel beds are common for the purpose of navigation maintenance, flood control, civil construction, etc. The post-dredge evolution of the mining-pit as well as the continuous changing of local flow and sediment transport, however, are poorly understood. The study simulates the morphological change of a large (1.46 million m³) borrow pit mined on a lateral sandbar in the lower Mississippi River using a depth-averaged two-dimensional hydrodynamic and sediment transport model. The model is calibrated and verified against 2.5 year time-series of multibeam bathymetric surveys. Besides, the study examined the sensitivity of mining-pit evolution simulation to the variation of the non-equilibrium adaptation parameters. Study results provide an insight into appropriate selection of the adaptation parameters in order to close the non-equilibrium sediment transport formulas when modeling large anthropogenic disturbance within the geomorphic processes.

Hangman Creek is one of the Spokane River’s largest tributaries, draining more than 400,000 acres of agricultural and forested land across four Washington and Idaho counties. The degradation of the Hangman Creek watershed has been frequently documented, with studies showing that the creek does not meet Washington State water quality standards. As part of their beaver solution program, the Lands Council (TLC) is investigating the use of beaver dam analogs (BDAs) as a cost-effective method for improving water quality by simulating the same ecosystem benefits as active beaver dams. BDAs are channel spanning structures that are semi-porous to water, sediment, and fish, and are biodegradable temporary features that simulate the ecosystem benefits of active beaver dams, but can be implemented where habitat may not be suitable for sustaining active beaver populations. In September 2016, TLC partnered with the U.S. Fish and Wildlife Service (USFWS) and Gonzaga University to design and evaluate BDAs in California Creek, a tributary to Hangman Creek. Gonzaga University has developed a long-term monitoring plan to strategically examine the effectiveness of BDAs to reduce sediment loads in California Creek. Monitoring efforts have occurred in since 2016 and include, repeat cross section surveys, sediment characterization, soil probing, and geomorphic change detection using repeat RTK surveys and repeat structure-from-motion aerial photogrammetry analyses. Over the past two years, spring floods acted to drastically alter channel morphology and damage the BDA structures. Using the results from drone video footage during the floods and design guidelines, efforts were made to modify, repair, and design new, more-resilient, BDA structures. This paper focuses on presenting the initial results of monitoring for sediment trapping effectiveness (using repeat cross section surveys, repeat RTK surveys, and pebble count data) and the adaptive management of the BDA structures in California Creek.

Barrier islands are characterized by narrow sandbars that often run parallel to the mainland and are separated by a lagoon or bay. These coastal features within the Northern Gulf of Mexico were formed during the late Holocene from waves and wind depositing sediment as well as the alluvial sediment supplied from the Mississippi River. As the name implies, barrier islands function as a critical ocean boundary that protects a mainland, bay, or estuary from storm surges, open ocean wave energy, and function as critical defensive systems for environmentally sensitive areas such as wetlands.

Cavalier, North Dakota, has suffered severe erosion and bank failures on the Tongue River in recent years. It lies downstream of ten dams that have greatly reduced peak flows and sediments. In addition, a historic steam-railway dam in town was decommissioned and replaced with lower rock weirs, resulting in a lower water surface elevation. An objective assessment approach using the latest streambank stabilization tools was used to evaluate the suitability of installing a series of taller rock weirs to stabilize the streambanks throughout the city. Various aspects of the river reach including hydrology, hydraulics, and sediment transport were modeled using the hydrologic model (HEC-HMS) and hydraulic model (HEC-RAS) developed by the USACE Hydrologic Engineering Center. The unsteady flow model geometry was created using LiDAR and surveying data, and the sediment transport model used gradation data collected at the time of survey. Streambank stability at a few sites was assessed based on the results obtained from the modeling.

The Hiram Chittenden Locks and Dam control the exchange of salt and fresh water between Puget Sound and the Lake Washington Ship Canal (LWSC). During each lockage the denser saltwater from the sound flows from the bottom of the locks into the lighter freshwater in Salmon Bay and proceeds to move upstream through the LWSC toward Lakes Union and Washington. This influx of water improves salmonid habitat near the locks by decreasing temperatures and increasing dissolved oxygen content, however it can have a detrimental effect on the freshwater environment in Lake Washington. Operations at the lock and dam must balance these competing water quality issues while maintaining the navigational ability through the locks. WEST Consultants, Inc. developed a two dimensional (vertical) temperature and salinity model of the LWSC in CE-QUAL-W2. The model simulates the inflows and outflows to the LWSC as well as the exchange of saltwater at the locks for 2014 and 2015. Saltwater exchange at the boundary is parameterized through an exchange coefficient. Modeled temperatures and salinities match observations well under high flow conditions but the model accuracy drops under low flow conditions. The model is most sensitive to the temperature and salinity boundary conditions at the downstream boundary where exchange with Puget Sound water occurs. Lock and dam operations drove the modeled parameters and accurate operational records were required to simulate the observed response.

A study is performed to analyze the water quality of a cooling reservoir of an existing nuclear power plant and a proposed expansion. The purpose of the daily water quality model is to estimate the required blowdown quantity and frequency from the reservoir to keep the cooling water conductivity level below a certain limit. The model is calibrated, and successfully validated against historical data from the operating plant. The model predicts water surface elevation and conductivity of the reservoir water, the daily diversion of makeup water (if available or allowed), and the daily blowdown (if necessary or allowed). A sensitivity analysis is performed on various parameters of the makeup and blowdown rules, to assess the impact on the water quality of the cooling reservoir. The model provides a useful tool, to modify and test the blowdown rules and assess the potential impact on the aquatic environment of the river.

The development and implementation of a stabilized finite element model (FEM) for the simulation of large scale geophysical flows using the shallow water equations (SWE) is presented. The model is derived from the mass and momentum conservative forms of the SWE, with wetting-drying implemented using a front tracking algorithm. Cartographic mapping is used to allow the use of Cartesian master elements when the meshing is performed in spherical coordinates. The model is validated using five applications, designed to test mass conservation as well as robustness of the wet-dry scheme, and the cartographic mapping implemented.

The primary flow rather than the secondary flow has been proven the dominant driving force for the evolution of a meandering channel. Understanding the shift of primary flow in meanders is also critical for engineers since it might flank bank protection structures or bringing unexpected dangers to river levees. This study modeled the shift of primary flow in a sine-generated mobile-bed channel by using a two-dimensional depth-averaged hydrodynamic and sediment transport model. The simulation was calibrated and verified by laboratory flume experiments. Our results indicated that the shifting of primary flow can be explained with the co-variations of transverse bed slope, d50, and flow discharge, namely, highly positively relating to the transverse bed slope, moderately negatively relating to d50, and weakly positively relating to flow discharge.

Water age is an important indicator for describing water exchange and pollutant transport in the lake. As the largest freshwater lake in China, Poyang Lake, with complex hydrodynamic condition is encountering serious environmental issues in recent years, for example water quality deterioration. A two-dimensional hydrodynamic model basing on environmental fluid dynamics code (EFDC) is established to calculate the water age in Poyang Lake. The results show that the water age in Poyang Lake has obvious spatiotemporal characteristics. The largest month is August, the smallest month is April. From the perspective of space, the water age in the main channels are significantly smaller than the bay regions. This paper make a quantitative analysis for water age, which will be helpful in understanding the hydrodynamic processes and benefit water quality management in Poyang Lake.

Dam break failures are often caused by overtopping of the dam due to inadequate capacity during large inflows into the reservoir from heavy precipitation run-off. The mathematical hydrodynamic simulation models can be used for prediction of dam breach flood hydrograph, and routing the same through downstream valley to get the time series of discharge and water level at different locations of the valley. The HEC-RAS model set up was prepared using the available data in the present paper. The critical condition for a dam break study is when the reservoir is at full reservoir level (FRL) and design flood hydrograph is impinged. Various breach parameters were considered for sensitivity analysis. The present study for project comprises of three hydrodynamic simulations using HEC-RAS mathematical model (a) PMF with dam break with initial reservoir level at FRL, (b) PMF discharge with no dam break, (c) PMF without dam in place (virgin condition). The maximum discharge, water level, velocity, and flood travel time at different locations of the river downstream of dam due to occurrence of PMF dam break are presented in the paper.

The main purpose of drawdown flushing is in clearing the area immediately surrounding the bottom outlets of the dam. Lateral soil slides are common during the flushing process, because the eroding water channel cuts down into the sediments. This paper documents numerical analysis for modeling lateral soil slide during reservoir flushing for assessing its effectiveness. A flushing event at hydropower reservoir in India was modeled with HEC-RAS 5.0.6, a quasi-unsteady, one-dimensional (1D), mobile bed sediment model. The coupling of 1D incision model with the toe scour and bank erosion model in HEC-RAS [the ARS-USDA bank-stability and toe erosion model (BSTEM)] was also modeled to account for the lateral pro-cesses and improve model performance in the lower half of the reservoir. BSTEM uses HEC-RAS hydraulics to determine water surface profiles and to compute the vertical distribution of shear stresses along the bank surface, and evaluates if cross section deposition or erosion simulated by HEC-RAS sediment transport exacerbates or improves bank stability. If BSTEM computes failure, HEC-RAS updates the cross section to reflect the updated bank geometry and adds the sediment load of the failed layers (by particle-size class) to the sediment transport model, routing it downstream. This paper documents the model coupling of HEC-RAS and BSTEM with an example application and comparison of results with model without BSTEM coupling.

As a tributary of Brahmaputra-Jamuna (hereinafter referred to as “Jamuna”) River, Teesta River joins into the trunk river at Rangpur in north-west of Bangladesh, and has been developed to be a significant irrigation system in this area. While due to insufficient observed sediment load sequences of Teesta River, neither the characteristics of siltation and erosion of the river bed nor the regularity of sediment transport are clarified. Based on analyses river bed form changes with runoff variations, it illustrate that the channel of Teesta River are wide and shallow with many gullies, and the main course shifts frequently with obvious aggradations and shrink in the latest years. Furthermore, the 1-D non-equilibrium non-uniformity sediment transport mathematical model is applied to probe and make clear the Teesta River evolution. The result shown that, the sediment transport capacity is following the classical equation of Q_s=kQ^α, with different k and α in different flow grade; the mean annual sediment load is around 31.4 million t, corresponding to the mean annual runoff of 25.2 billion m³. The study would supply the significance for guiding Teesta River sustainable development.

The 5th Ave. Dam was a low head dam located just upstream of the 5th Avenue Bridge crossing the Olentangy River, near Downtown Columbus, OH. A local non-profit watershed group submitted and received approval from the Ohio Environmental Protection Agency (OEPA) in 2005, on an action plan that identified the 5th Ave. Dam as one element that adversely affected the water quality of the Lower Olentangy River. The city of Columbus worked collaboratively with various partners to remove the dam in 2014 and undertake an environmental restoration (in combination referred to as ecosystem restoration) of the Olentangy River near the dam and its pool area. Initially constructed in 1935, the 500 feet wide and 8 feet tall dam provided a constant pool for the cooling water intake at the Ohio State University power plant. The impounded segment of the river extended several thousand feet upstream of the 5th Avenue Dam and did not meet use attainment goals set by the OEPA. The dam removal, subsequent restoration of the Olentangy River resulted in net improvements to water quality and aquatic community composition and furthered efforts to meet use attainment goals.

This paper presents numerical simulation studies on wave attenuation and setup/runup in wetland and vegetated by using a one-dimensional (1D) wave model (CSHORE) and a 2D wave spectral model (CCHE2D-Coast). Two wave breaking criteria implemented into the two models are examined by simulating wave heights and setup in a vegetated laboratory flume. Comparisons of wave heights show that the two breaker models perform similarly well in the cases with and without vegetation. The 2D spectral wave models enable to provide details of frequency distribution of wave energy and vegetation damping effect in each frequency of spectral waves. For simulation of setup/runup, vegetal drag forces based on linear and nonlinear wave theories are examined. By employing the 1D and 2D models, drag force formulations are investigated by computing the mean water levels (MWL) in the vegetated sloping beach. Intercomparison of numerical model results reveals that the linear drag force can provide a reasonable setup in a non-vegetation beach, but overestimates MWLs in vegetation zone while overpredict wave runup. On the other hand, the nonlinear vegetal drag force enables to reproduce the on-off shore profile of MWLs.

In water distribution systems, one of the main problems has been the leakages generated by several factor such as pipe breakages or joint failures, among others, having an important impact in the performance indexes of water utilities such as non-revenue water index (NRW). Due to the close relationship between pressure and leakages, the pressure management approaches has demonstrated the best performance for reducing the water losses in water distribution systems. In this research, two different methodologies were proposed for comparing which approach is more efficient in the reduction of water losses: first, the optimal location of pressure reducing valves (PRV) using NSGA-II, and secondly, the optimal location and selection of pumps as turbines (PAT) using SPEA2. A well-known benchmark network was used to test the proposed methodologies, leading to the comparison between the obtained results.

Revealing spatial patterns exhibited by pipe failures can help improve the understanding of the significant factors that influence the deterioration of piping conditions. In this study, spatial autocorrelation analysis, based on the global and local indices of Moran’s I, is applied for the identification of spatial patterns of pipe failure in drinking water distribution systems. First, global Moran’s I is implemented for revealing the degree to which pipe failure events are clustered in space, and to examine the statistical significance of the observed clustering. Second, local Moran’s I is used to identify the locations of statistically significant hotspots and coldspots of pipe failures. The proposed framework is applied to a set of historical pipe failures extracted from the maintenance records of a large metropolitan water utility. For the studied system, the analysis revealed that pipe failures exhibit a significant degree of spatial clustering, and identified the locations of failure hotspots and coldspots. The observed clustering was found to be driven in part by the distribution of pipe density across the different sections of the distribution system. Yet, failure data still exhibited significant clustering even after accounting for pipe density, which suggests that other pipe attributes (e.g. pipe material, age, and size) could also be driving the clustering behavior.

Tyrol is a federal state of Austria inheriting 279 municipalities. Authorities of those municipalities operate water distribution systems that supply water for less than 5,000 inhabitants although some of them are larger than Paris metropolitan area. Due to long networks paired with relatively low income (because of a small number of consumers), advanced water loss strategies and highly qualified manpower are too expensive. Thus, this paper specifies and discusses legal requirements and state funding for water loss management in Austria. Further, it gives insight in different standard strategies and discusses the applicability of those to very small municipalities (less than 5,000 consumers). Finally, the results of compiled water loss statistics are presented and evaluated. It can be substantiated that for very small municipalities, there is a lack of reliable data for rehabilitation works. Therefore, rehabilitation planning based on pipe survival curves is no adequate instrument to reduce water loss. In contrast, on-line flow metering can lead to minimal night network inflow of less than 3% of the average demand. The evaluation of state funded leakage detection campaigns shows that with adequate countermeasures, water loss can be reduced significantly.

In water distribution systems, pressure transients provide information about the state of the system and its response to changes in operations, demand fluctuations, and pipe failures. Advanced sensing and data logging techniques enable exploring and characterizing pressure transient patterns, which are typically estimated through modeling and simulation, if not ignored. In this study, an approach based on time-series clustering is proposed to discover patterns in pressure transients from high-resolution pressure signals, which are collected by a network of pressure sensors. Six widely used clustering algorithms are tested to identify repeating patterns: k-means, k-medoids, hierarchical clustering, density-based spatial clustering of applications with noise, affinity propagation, and clustering by fast search and find of density peaks (SFDP). Three performance scores are suggested to evaluate and compare the quality of the results, including Silhouette coefficient, sum of squared errors, and Calinski-Harabaz index. Initial simulations indicate that k-means and SFDP consistently provide better performance results compared to other algorithms as well as being computationally efficient.

Many different aspects of water distribution systems have been in the focus of optimization. One aspect is the multi-objective design of the pipe network, resulting in a set of trade off (Pareto) network solutions. While the complex nature of water distribution systems has already been explored, literature is lacking of an investigation of the complex graph characteristics of optimal networks. To explore network characteristics and patterns of optimal networks, a water distribution system is optimized with a multi-objective approach considering costs and resilience. Besides characterization of the topology of the investigated network, also, the multitude of Pareto solutions is investigated with different graph measures taking into account structural, hydraulic, and water quality features. E.g. it was determined that the edge betweenness centrality from the water source drives the layout of the optimal solution for low resilience values and with an appropriate weighting function for the graph there is a linear correlation between the shortest path lengths and the nodal water ages (R²=0.965).

In the event of a disruption of operation, parts of the water distribution networks (WDNs) must be temporarily disconnected from the supply source by the closure of isolation valves to allow pipe repair. For cost reasons, however, the number of such valves is usually limited, requiring strategies for their optimal placement. In this paper we combine graph theoretical approaches with reliability analysis by using the WDN topology and isolation valve information. A novel methodology for the assessment of valve placement strategies is developed, in which we investigate WDNs in their information space by means of complex network analysis. Unlike traditional approaches, we use the dual representation of the network, where WDN segments (i.e., a set of pipes) are considered as nodes and isolation valves as edges. With the developed algorithm, the WDNs are analyzed on the basis of the dual graph, providing new insights beyond a conventional graph (primal mapping) analysis. The method is applied to two real-world systems, to identify different patterns with respect to the probability density functions of (dual) node properties: node-degree P(k), aggregated pipe length P(l), and demand P(d). Additional complex network metrics, such as the characteristic path length, degree correlation, and modularity are investigated and discussed. The observed topological differences also reflect the availability of financial resources and the different types of water supply of the systems. The implications of the results allow for a novel assessment of WDN reliability and robustness in the event of disruption and network isolation.

The pipe distribution networks (PDNs) are gaining importance over conventional canal system of trasporting irrigation water due to their efficiency in water use and adaptability with the modern system of irrigation such as drip and sprinkers. The other significant advantage with PDN is that no acquisition of land is necessary as pipes are laid underground. The underground pipes on the open fields give an opportunity to have a cross-country layout. Further, instead of connecting nodal points directly, some additional nodes (Stenier Points) can be considered to minimize the cost. A new iterative methodology is proposed in this study. The iterative process starts with initial Steiner point layout obtained using GEO STEINER software, and optimized for pipe sizes using linear programming. The layout and pipe sizes are successively corrected until no further reduction in cost is observed. The method is applied to a few example networks and the results are compared to show the advantage of the proposed methodology.

The organization of water distribution networks is understudied compared to their structure and function. The system architecture of water infrastructure networks includes not only spatial topology, but also functional and logical architecture. The use of graph theory to analyze spatial topology has found that water networks display non-scale-free degree distributions and thus conclusions regarding the vulnerability to certain failures/modes of attack are drawn. However, other facets of the architecture have not been investigated or supplemented to these results. This study uses network analysis to elucidate the logical architecture of benchmark water distribution systems, comparing it to the spatial topological characteristics reported in the literature. Logical consequence networks are generated by examining failure propagation (i.e. physical and performance failure results due to excess or insufficient pressure after failing single components) via hydraulic simulation. Results suggest that caution must be used in drawing conclusions from a single architectural facet of complex networks such as water distribution systems, because the topologic characterization of stress propagation may be different than the physical characterization due to internal hydraulics.

This study examines the influence of the quality of hydraulic model calibration on the accuracy of model-based leak localization. It is based on a real-world case study where pressures were measured at 12 positions for more than 4 months. Fire flow tests were performed to obtain calibration data— artificially generated leaks with different sizes between 0.25 l/s to 1 l/s at 4 different positions served as dataset for model-based leak localization. Three different calibration approaches were applied on an uncalibrated model generated from GIS data: (i) height adjustments of measurement positions through detailed analysis of long term pressure signals in the leak-free system; as well as (ii) manual trial and error calibration; and (iii) automatic calibration with fire flow test data. The height-adjusted model lead to increased leak localization accuracy compared to the uncalibrated GIS model. However, the most significant improvement was achieved through fire flow test based calibration— revealing a partially closed valve in the system. The auto-calibrated model, which simultaneously calibrated roughness and minor loss coefficients, provided the highest leak localization accuracy.

Algae and bacteria can grow in water storage tanks when the water is stagnant. Although many variations of storage tank exist, many have the inlet and outlet pipes at the tank bottom. Stagnation occurs in the top portion of the tank from which water is not used since it is kept for emergencies only. A simple and passive method was developed in this study that mixes water in the entire tank without using electricity like mechanical mixing devices. The new device consists of a riser pipe in the tank center that leads to eight-arm sprinkler-type piping that extends above the entire tank surface. Diffuser holes are located along the bottom of all the sprinkler arm pipes from which water falls even along the entire tank surface. To ensure that all water particles fall directly down and thereby mix all the tank’s water a corresponding “inverse sprinkler” is used for drainage out of the tank. This drainage sprinkler has eight arms with the same location of holes as the top sprinkler, this time on the top of the piping for the eight arms. The device requires only some additional piping be put into an existing or new tank. The new piping is low cost, since it could be from commercially-available seizes and material such as PVC. Laboratory experiments were conducted both with and without the new mixing device. Dye testing and detailed three-dimensional acoustic Doppler velocimeter measurements show a significant increase in mixing throughout the tank with no stagnation zones to allow the growth of algae or bacteria, thereby improving public health. The new device, therefore, is concluded to be an effective and passive and sustainable way to eliminate stagnation in water storage tanks and thereby improve public health.

This study proposes to build upon recent studies on the placement and utilization of water quality sensors in water distribution systems to develop an integrated framework to detect and respond to a potential contamination event. In addition to fixed-location sensors, recently developed mobile sensors can transmit water quality data to assist in the characterization of a contamination event. The resulting information from both sensor types is necessary for plume forecasting and locating the contaminant source, which is required to assist in the remediation of the system. In addition to detecting a potential event, the ability to represent the dynamics associated with a contaminant can further assist in remediation activities. While most efforts have focused on reactions in the bulk fluid, the potential for adsorption of the contaminant on the corroded pipe walls and the potential release of adsorbed contaminants is a threat to the health of the consumer over a long time horizon. Therefore, a method has been developed to estimate the long term desorption of the contaminant cadmium and solutions proposed to integrate this knowledge into an automated long-term recovery system.

Contaminant(s) intrusion into water distribution systems (WDS) may have an adverse effect on large populations. The pipeline corrosion scale has the capability to adsorb the contaminant and thereafter release it to water once the system is returned to operation, causing secondary contamination. Therefore, overcoming contamination events should remove the contaminant from both aqueous and scale phases in a controlled fashion, while not jeopardizing the WDS integrity, nor causing red-water events. This study examined the adsorption and subsequent release of cadmium, as a representative heavy-metal ion, from representative pipeline corrosion scales. Adsorption/desorption batch experiments were conducted on corrosion scales peeled off from old domestic WDS pipes. The effect of water quality (pH, alkalinity, ionic composition, [Cd²⁺]) on Cd(II) adsorption and release was examined. The corrosion scale showed high Cd²⁺-absorption capacity and linear relation between [Cd²⁺] and the adsorbed Cd. Desorption experiments included dosages of various acid types, Na₂S, and KCl. HCl dosage to pH3 was found a suitable technique, releasing ~90% of the adsorbed Cd(II). The work conclusions will serve to design continuous adsorption/desorption experiments, with the aim of determining the optimal rehabilitation treatment.

Isolation valves are critical elements in water distribution system since they enable water utilities to perform maintenance on the system without the need to shut down large parts of the system. In this paper several isolation valve configurations in terms of the density of valves are used in a case study. The results show that the failure of an individual isolation valve can significantly impact any shutdown. The density of valves in the network determines impacts of inoperable valves during a shutdown. Several conclusions drawn from the critical valve analysis in this study could be applied to guide the isolation valve management. The key findings are that increasing the density of valves improves resilience and some valves are much more important than others.

The fractal dimension in water distribution networks (WDN) can be seen as an indicator or a scaling factor of how much the network changes topologically, according to the scale in which it is analyzed. The fractal dimension of a considerable number of networks with different characteristics was calculated in order to study its behavior and have a better understanding of this feature. Three different criteria were used to calculate the weight of each node in the box covering algorithm used to determine the fractal dimension: topology, SumQ, and HGL*SumQ. All of the studied networks resulted to be fractal networks since the coefficient of determination $\left(R^2\right)$ of the linear fit after applying the box covering algorithm was always above 0.95. The largest values for the fractal dimension were obtained with the topology weight criterion. There was not a clear tendency in the variation of fractal dimension when modifying the networks’ demands and calculating the weights with the proposed hydraulic criteria (SumQ and HGL*SumQ).

The box covering algorithm, used to calculate the fractal dimension in water distribution networks (WDNs), was proposed as an alternative to identify possible district metered areas (DMAs) in WDNs. By using hydraulic criteria (SumQ and HGL*SumQ) in the method’s node weight calculations, tests on Cazucá, Exnet, and Santa Marta networks were carried out in order to establish possible divisions into DMAs. The quality of these divisions was measured using the modularity index. These divisions were then compared to those obtained with the community detection algorithm which guarantees the maximum modularity possible starting from every node as a single independent DMA. Divisions with relatively high modularity were obtained using the box covering algorithm, however, their modularity was never as high as the ones obtained with community detection. Therefore, the methodology proposed could be a viable alternative to identify potential divisions into DMAs in large and complex WDNs.