This paper presents the approach followed by WaterNetGen – an EPANET extension – to simulate water distribution systems considering both normal pressure and pressure-deficient scenarios. WaterNetGen models pressure-deficient scenarios by incorporating a pressure-demand relationship, which computes the available demand as a function of the current pressure, and considering leakage at pipe level (background and bursts). This new capability is fully integrated into the original EPANET interface, so the same network model can be used to perform demand-driven and pressure-driven analysis, leading to a faster a more accurate modelling of water distribution systems

This paper focuses on the generation of synthetic models of water distribution networks (WDN). Models are widely used in many fields related with WDN planning and operation. Therefore, the main contribution of this work is to provide an automatic procedure to build models with the well-known EPANET tool in a manner that, with a small amount of input data and a few clicks, the user can build a network topology and assign suitable pipe diameters. For that purpose, a new application, called WaterNetGen, was designed and implemented as an extension to the EPANET software. WaterNetGen can be used to generate synthetic models of WDN, with several hundred nodes and pipes, within a few minutes. The sizing capability allows the selection of commercial diameters, such that the final network design satisfies certain user-defined design constraints, like minimum diameter, maximum velocity and minimum pressure. The total water demand is allocated to the pipes taking into account their length and a demand coefficient. The water demand of each pipe is then assigned to its start and end nodes and follows a specific demand pattern.

This paper explores the use of Technical Performance Indexes (TPIs) to assess the operational performance of Water Distribution Networks (WDNs) and exemplifies its suitability to easily identify problematic zones. The paper also points out some problems associated with the existent TPIs and proposes new analysis tools to avoid these difficulties. These new analysis tools (such as state variable slack and constraint violation) are conjugated with the pressure-driven simulation model for illustration purposes, including operational performance assessment during pipe bursts or firefighting scenarios, and to identity and account for the “demand not satisfied” due to those events

This paper addresses the problem of locating leaks in water distribution networks. The approach presented here is based on steady-state modelling, supported by monitoring tank flow and pressure at strategic nodes. The selection of the pressure monitoring nodes is done applying graph theory concepts adapted to water distribution networks. Pressure monitoring data is then used to build an optimization problem: the objective function is the minimization of the differences between estimated and measured pressures at the monitoring points, the constraints are the common energy and mass conservation laws and the decision variables are the leak locations and flows. This optimization problem is solved by a simulated annealing algorithm presented in a previous work. The application of this approach in a set of case studies produced some encouraging results and this paper describes the complete procedure and draws some conclusions

This paper focuses on modeling and calibration of a small and poorly documented (portion of the) water distribution network (WDN) that shows pressure problems. Field campaigns are conducted to reduce the inaccuracies found in the inventory's drawings and to aid building a first WDN model. A trial and error procedure was then used to produce successive refinements for the desirable WDN's model fit. The paper describes the path followed through the first model to the final calibrated model, including WDN's instrumentation, the definition of network zones and the measures taken to deal with the pressure problems

Sustainability is a major issue for water companies, who have to provide high quality services at achievable costs. In this context, water loss control and energy efficiency are two great challenges water companies have to face. Water loss represents both higher service cost (real losses) and loss of revenue (apparent losses), while the energy bill from treatment plants and pumping stations represents a significant part of the service cost. The Battle of Background Leakage Assessment for Water Networks (BBLAWN) was a competition dedicated to this subject: water distribution network (WDN) optimal management. Teams/individuals from academia, consulting firms, and utilities were invited to propose methodologies for solving the C-Town WDN problem: minimize operational and capital costs and background leakages. This paper presents one of the methodologies proposed at BBLAWN. The methodology proposed here to solve the C-Town WDN problem comprises two optimization models: a least-cost design model to ide...