Asset management is a broad term and a relatively new paradigm to water industry. This paper is intended to present an overview of the asset management approach that emerges as a managerial and technical framework for a water utility to effectively manage above and below ground assets. Based upon the lessons learned from some limited practices in the developed countries including UK, USA, Australia and New Zealand, the article is focused on elaborating the new concept of asset management and technological requirements to implement it for a water or wastewater organization. Following the brief overview, the elements of asset management are addressed along with the classified essential technology that enables water asset management and the potential cost savings resulted from an effective program. It concludes by looking into the challenges and barriers for adopting this innovative approach.

A one-dimensional hydrodynamic numerical model has been developed and implemented into Haestad Methods? hydraulics software for modeling of unsteady flows in sewer and storm water urban drainage system. The new numerical model uses an implicit four-point, finite-difference solution technique to solve the one-dimensional Saint-Venant equations. Advanced numerical techniques, such as local partial inertial modification (LPI) for subcritical, supercritical, and transitional flows, and relaxation for pipe/channel networks, are used to achieve computational performance and robustness as required for practical use in a water resources engineering commercial software package.

Stormwater management systems are critical to urban populations, and the consequences of storm sewer system failures can be catastrophic ? ranging from damage to property and possessions by flooding, through to the spread of disease and even death. In recent times India?s stormwater management systems have been placed under enormous strain by flooding problems throughout the country, and it is clear that many of these storm sewer systems require dramatic improvement (Times of India, 2005). However the analysis and design of stormwater systems is far from straight forward, and the planning of system improvements is further complicated by the need to prioritize system upgrades to maximize the benefits of capital expenditure. Fortunately, hydraulic models based on geospatial data can be leveraged as a key tool for supporting investment decisions for storm sewer infrastructure.

Thomas Walski provides some insight about the data needs for performing high quality hydraulic analysis and how to avoid pitfalls for such modeling.

Water distribution modeling and SCADA technology has evolved immensely in recent decades. A few years ago, integrating SCADA with WaterCAD would have been a formidable task because of technological limitations. However, now, because of advances in the software, integration for the two technologies has become a realistic target. Bristol Babcock offers a commercial SCADA system called Open Enterprise and Haestad Methods produces the water distribution modeling software solutions WaterCAD and WaterGEMS. These programs offer the programming-level customization technology known as WaterObjects, which can be used to extend the functionality of WaterCAD and WaterGEMS. In this joint effort project between the City of Bethlehem, Bristol Babcock Inc., and Haestad Methods Inc, WaterObjects was used to develop integration with Bristol Babcock?s open enterprise for the city of Bethlehem (PA).

Identifying how much water is being lost from water networks and where the losses are occurring is of great importance to water utilities both for operational and planning reasons as well as for reputation. In this paper, an optimization-based approach is presented for simultaneously quantifying and locating water losses via the process of hydraulic model calibration. The model calibration is formulated as a nonlinear optimization problem that is solved by using a genetic algorithm. The method is developed as an integrated framework of hydraulic simulation and optimization modeling. Case studies are presented to demonstrate how the integrated approach is applied to water loss detection. The results obtained show that the method is effective at detecting water loss as part of the hydraulic calibration of the network model.

Hydraulic modeling needs of Chatham-Kent solved with Bentley?s Haestad methods technology, saving the municipality tens of thousands of dollars per year.

Placement of water quality sensor has received an increasing concern for timely providing the warning of possible contamination in a water system. Due to the large dimension of water distribution network and the difficulty for predicting where a contamination event occurs, it is a great challenge for engineers to come up with good sensor locations with any confidence to effectively detect possible contamination events. The problem is complicated by the fact that sensor location is evaluated against a number of objective criteria that may include the detection likelihood, the expected detection time, affected population and contaminated water consumption. A design that improves one objective may deteriorate another. In this paper, sensor placement is formulated as a multi objective optimization problem that is solved by using a competent genetic algorithm while the contamination events are simulated by the latest development of Monte Carlo method.

A hydraulic network model was constructed for the city of Sidney, Ohio water distribution system. It consists of 104 miles of water mains, some of which are well over a hundred year old and serve the original part of the system. The city intends to use the model for available fire flow analysis and a variety of many other applications. It is essential that the hydraulic model be able to accurately simulate the real system conditions. Model calibration is the critical step to achieve this goal. To calibrate the model, Sidney?s public utility department collected the pressure data at twenty locations, along with the boundary conditions of the observed tank levels and pump operating status. The calibration proceeds by applying a well-integrated hydraulic simulation and genetic algorithm optimization modeling platform in two phases including the systemic demand calibration to establish an extended period flow balance model and hydraulic grade calibration under multiple loading conditions.

Water distribution modeling software provides South Australian water corporation with efficiency and time savings for model building, design and analysis

Conventional water distribution models are formulated under the assumption that water consumption or demand defined at nodes is a known value so that nodal hydraulic head and pipe flows can be determined by solving a set of quasi-linear equations. This formulation is well developed and valid for the scenarios that the hydraulic pressures throughout a system are adequate for delivery the required nodal demand. However, there are some scenarios where nodal pressure is not sufficient for supplying the required demand. These cases may include the planned system maintenances, unplanned pipe outages, power failure at pump stations, and insufficient water supply from water sources. In this paper, a robust and efficient approach for pressure dependent demand analysis is developed for simulating a variety of low pressure scenarios.

Identifying and quantifying the critical elements in a water distribution system has traditionally involved a great deal of judgment. With the coming of computerized hydraulic analysis, it became easier to ?fail? a pipe in a distribution system to assess its impact on service. However, when a failure occurs in a real system, it does not remove a single pipe from a distribution system but rather a ?segment? which can be isolated using valving. A segment will often include several nodes, portions of pipes, and other elements. In this paper, the critical segments in a real system are identified based on existing valving. Then different rules for valve installation (e.g. n valves per junction, n-1 valves per junction) are used to add or remove isolating valves from the system and determine the performance of the system as a function of the density of valving.

Customized water distribution modeling software proves to save substantial time and cost

Water distribution system analysis did not begin with the development of digital computer programs. Engineers were successfully designing, constructing and operating water distribution systems long before the coming of the computer age. This paper traces the development of analysis from Archimedes and the roman aqueducts, through the development of principles of fluid flow by Newton, Bernoulli and Euler to the development of head loss equations by Chesy, Darcy, Weisbach, Hazen, Williams and moody. It then looks at how principles developed for individual elements where combined to solve network problems by cross and the subsequent development of analog computer methods. The paper will show how our understanding of hydraulics did not come about quickly but through an unraveling of one problem after another by some brilliant individuals.

Methods to automatically calibrate water distribution system models have been available for some time but it is very difficult to prove that any method is correct. Since at any one time the ability to know all the usage and flow conditions in a real system is impossible, obtaining all of the data needed in a real water distribution system to obtain an accurate and complete data set for model calibration is unrealistic. To test the ability of automated calibration methods to predict the actual conditions in a water system a laboratory scale physical model of a water distribution system was constructed and an automated water distribution model calibration program, employing genetic algorithms, was used to calibrate the model of that system. The paper describes how the lab data were collected, and how the calibration program matched the lab data and provides some suggestions for users of an automated water distribution calibration model.

Asset management is a broad term and a relatively new paradigm to water industry. This paper is intended to present an overview of the asset management approach that emerges as a managerial and technical framework for a water utility to effectively manage above and below ground assets. Based upon the lessons learned from some limited practices in the developed countries including UK, USA, Australia and New Zealand, the article is focused on elaborating the new concept of asset management and technological requirements to implement it for a water or wastewater organization. Following the brief overview, the elements of asset management are addressed along with the classified essential technology that enables water asset management and the potential cost savings resulted from an effective program. It concludes by looking into the challenges and barriers for adopting this innovative approach.

A water distribution system provides water services to customers under normal and abnormal conditions. It is important for water companies to be informed to what degree or level that a water system is able to supply its customers when an emergency or calamity scenario occurs. Such an abnormal event can cause one or more than one element out of service. When such an event occurs, pressure is often lower than the operating condition. Consequently the service can only be maintained to a certain level, the supplied demand is not as much as the expected before the outage is fully recovered. In this paper, a new approach is developed and presented to accurately simulate those abnormal events.

A water quality model is to predict water quality transport and fate throughout a water distribution system. The model is not only a promising alternative for analyzing disinfectant residuals in a cost-effective manner, but also a means of providing enormous engineering insights into the characteristics of water quality variation and constituent reactions. However, a water quality model is a reliable tool only if it predicts what a real system behaves. This paper presents a methodology based upon fast messy genetic algorithm that enables a modeler to efficiently calibrate a water quality model such that the field observed water quality values match with the model simulated values. The approach is integrated with a well-developed hydraulic and water quality modeling system. It provides a generic tool for engineers to construct the sound water quality model in expedient manner.

Thomas Walski provides some insight about the data needs for performing high quality hydraulic analysis and how to avoid pitfalls for such modeling.

Even though the required data have been collected and entered into a hydraulic simulation software package, the modeler cannot assume that the model is an accurate mathematical representation of the system. The hydraulic simulation software simply solves the equations of continuity and energy using the supplied data; thus, the quality of the data will dictate the quality of the results. The accuracy of a hydraulic model depends on how well it has been calibrated, so a calibration analysis should always be performed before a model is used for decision-making purposes. Calibration is the process of comparing the model results to field observations and, if necessary, adjusting the data describing the system until model-predicted performance reasonably agrees with measured system performance over a wide range of operating conditions. The process of calibration may include changing system demands, fine-tuning the roughness of pipes, altering pump operating characteristics, and adjusting other model attributes that affect simulation results.

Skeletonization of water distribution model allows the city to comply with two different department?s model requirements for major cost savings

A geographic information system (GIS) is a powerful configuration of computer hardware and software used for compiling, storing, managing, manipulating, analyzing, and mapping (displaying) spatially-referenced information. GIS is becoming an increasingly valuable tool for the water distribution modeler both as a source for modeling data and as a decision- support tool. In the past, most models were developed with a batch-run philosophy in which a text file containing the model data was required to drive the model. Gradually, models gained the ability to interact with databases that were either internal to the model or more general and commercial. Finally, because a GIS is essentially a spatially aware database, ongoing development has led to models that are highly integrated with GIS. This paper contains background information on GIS development and uses for both water model creation and other application areas.

Tap water has been taken for granted as a daily resource for many people, but it may not be well known that genetic algorithm optimization has been playing an important role in managing and operating municipal drinking water systems by means of hydraulic and water quality models. Computer models have been built for analyzing water distribution systems since the mid-1960s. The models have become important tools for engineers to simulate various system scenarios. However, before hydraulic and water quality models can be used for analysis and operational study of a real system, a model must be able to accurately predict what happens in a real system. The accuracy of modeling results is dependent on a set of model parameters that must be optimized for each water system. Over the last four decades, several approaches using optimization techniques have been proposed for model calibration.

Asset management is a broad term and a relatively new paradigm to water industry. This paper is intended to present an overview of the asset management approach that emerges as a managerial and technical framework for a water utility to effectively manage above and below ground assets. Based upon the lessons learned from some limited practices in the developed countries including UK, USA, Australia and New Zealand, the article is focused on elaborating the new concept of asset management and technological requirements to implement it for a water or wastewater organization. Following the brief overview, the elements of asset management are addressed along with the classified essential technology that enables water asset management and the potential cost savings resulted from an effective program. It concludes by looking into the challenges and barriers for adopting this innovative approach.

Water distribution modeling and SCADA technology has evolved immensely in recent decades. A few years ago, integrating SCADA with WaterCAD would have been a formidable task because of technological limitations. However, now, because of advances in the software, integration for the two technologies has become a realistic target. Bristol Babcock offers a commercial SCADA system called Open Enterprise and Haestad Methods produces the water distribution modeling software solutions WaterCAD and WaterGEMS. These programs offer the programming-level customization technology known as WaterObjects, which can be used to extend the functionality of WaterCAD and WaterGEMS. In this joint effort project between the City of Bethlehem, Bristol Babcock Inc., and Haestad Methods Inc, WaterObjects was used to develop integration with Bristol Babcock?s open enterprise for the city of Bethlehem (PA).

A geographic information system (GIS) is a powerful configuration of computer hardware and software used for compiling, storing, managing, manipulating, analyzing, and mapping (displaying) spatially-referenced information. GIS is becoming an increasingly valuable tool for the water distribution modeler both as a source for modeling data and as a decision- support tool. In the past, most models were developed with a batch-run philosophy in which a text file containing the model data was required to drive the model. Gradually, models gained the ability to interact with databases that were either internal to the model or more general and commercial. Finally, because a GIS is essentially a spatially aware database, ongoing development has led to models that are highly integrated with GIS. This paper contains background information on GIS development and uses for both water model creation and other application areas.

A one-dimensional hydrodynamic numerical model has been developed and implemented into Haestad Methods? hydraulics software for modeling of unsteady flows in sewer and storm water urban drainage system. The new numerical model uses an implicit four-point, finite-difference solution technique to solve the one-dimensional Saint-Venant equations. Advanced numerical techniques, such as local partial inertial modification (LPI) for subcritical, supercritical, and transitional flows, and relaxation for pipe/channel networks, are used to achieve computational performance and robustness as required for practical use in a water resources engineering commercial software package.

Stormwater management systems are critical to urban populations, and the consequences of storm sewer system failures can be catastrophic ? ranging from damage to property and possessions by flooding, through to the spread of disease and even death. In recent times India?s stormwater management systems have been placed under enormous strain by flooding problems throughout the country, and it is clear that many of these storm sewer systems require dramatic improvement (Times of India, 2005). However the analysis and design of stormwater systems is far from straight forward, and the planning of system improvements is further complicated by the need to prioritize system upgrades to maximize the benefits of capital expenditure. Fortunately, hydraulic models based on geospatial data can be leveraged as a key tool for supporting investment decisions for storm sewer infrastructure.

A geographic information system (GIS) is a powerful configuration of computer hardware and software used for compiling, storing, managing, manipulating, analyzing, and mapping (displaying) spatially-referenced information. GIS is becoming an increasingly valuable tool for the water distribution modeler both as a source for modeling data and as a decision- support tool. In the past, most models were developed with a batch-run philosophy in which a text file containing the model data was required to drive the model. Gradually, models gained the ability to interact with databases that were either internal to the model or more general and commercial. Finally, because a GIS is essentially a spatially aware database, ongoing development has led to models that are highly integrated with GIS. This paper contains background information on GIS development and uses for both water model creation and other application areas.

Tap water has been taken for granted as a daily resource for many people, but it may not be well known that genetic algorithm optimization has been playing an important role in managing and operating municipal drinking water systems by means of hydraulic and water quality models. Computer models have been built for analyzing water distribution systems since the mid-1960s. The models have become important tools for engineers to simulate various system scenarios. However, before hydraulic and water quality models can be used for analysis and operational study of a real system, a model must be able to accurately predict what happens in a real system. The accuracy of modeling results is dependent on a set of model parameters that must be optimized for each water system. Over the last four decades, several approaches using optimization techniques have been proposed for model calibration.