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Numerous methods and tools have been proposed to manage water losses in water distribution systems. These methods generally involve time-consuming and costly processes. Since the dynamic structure of each system is different, the applicability of the methods should be analyzed before applying the methods. In this study, a novel system is developed to analyze the current condition of utility and to assess the data quality and current implementation level of water loss management (WLM) practices. This system consists of a total of 144 WLM components under eight main categories. Pilot utilities are selected to test the feasibility of the developed model and analyze its behavior in the field. Weaknesses and strengths within the scope of WLM are defined separately for each utility. It was understood that the model developed takes into account the dynamic structure of each utility, is applicable in the field, and presents the current condition in a realistic way. It is thought that the developed model will create a reference, especially for practitioners and decision makers in the field, and will provide important benefits in the scope of WLM. [ABSTRACT FROM AUTHOR]

The paper describes and discusses the application of a guided evolutionary approach for the optimization of water distribution networks. Initially developed for the Battle of the Water Networks II (BWN-II), the approach was adapted and improved for competing in the Battle of Background Leakage Assessment for Water Networks (BBLAWN). The proposed evolutionary approach operates in an exclusively discrete solution space and is intended to require as little engineering judgment and time as possible while attaining acceptable and informative results that are useful for decision making. Its main features are custom crossover and mutation operators specific for water distribution network optimization tasks. A simple postprocessing greedy algorithm to locally refine pipe replacements is introduced as a means of complementing the evolutionary approach. [ABSTRACT FROM AUTHOR]

The magnitude and duration of corn transpiration reduction during center-pivot sprinkler irrigation was analyzed on a commercial plot. The irrigation event was defined as the period during which the pivot arm was passing over the transect AC and water droplets were moistening the plants (moist treatment). Corn transpiration rates were measured at three spots of that transect and simultaneously at another spot (dry treatment) located approximately 270 m east from the transect AC. Corn transpiration rates for the moist treatment location were reduced by 30-36% compared to the dry treatment location during the irrigation event. After irrigation, the transpiration reduction lasted for 1.8-2.6 h, and ranged from 22-29%. The gross wind drift and evaporation losses ranged from 10-13% of the applied water, whereas the net interception losses were 2% of the applied water. Considering the observed corn transpiration reduction during and after the irrigation, the net sprinkler evaporation losses ranged from 11-13% of the applied water, with no relevant differences along the pivot arm. [ABSTRACT FROM AUTHOR]

Pressure control is a key issue for the reduction of water loss through leakage in municipal water distribution networks (WDNs). The paper presents a general method to calibrate the proportional controllers for the real time control (RTC) of motorized pressure valves in WDNs to reduce leakage during ordinary operation. The method is based on the comprehensive dimensionless analysis of the behavior of simplified hydraulic systems under RTC scenarios. A numerical approach was used to derive a simple regressive relationship to tune the controller on the basis of the system dimensionless variables involved in the control process. The method was validated by application to a well-known bench-test water distribution network and compared with an existing literature calibration procedure. Results show that the proposed method allows for effective controller tuning and leads to performing leakage reduction-oriented real time control of pressures. [ABSTRACT FROM AUTHOR]

Municipalities in the Kingdom of Saudi Arabia (KSA) are putting serious efforts into reducing the water losses to around 8% (i.e., national benchmark) of supplied water through active leakage control (ALC). In this research, a framework is conceptualized and developed to establish economic level of leakage (ELL), keeping in view the specific conditions of arid regions. In general, water loss control actions, including ALC, passive leakage control, pressure management, and infrastructure asset management, are performed by the municipalities up to the service connections until the cost of these actions becomes equal to the cost of the water lost. For the explicit scenario of KSA, the framework also investigates the possibilities of water losses beyond the property line where water is intermittently supplied for a certain duration in a week and stored in underground tanks to ensure a continuous supply within the house. Night flow analyses were conducted to establish the relationship between pressure and water losses. The framework is implemented on a case study in the Alryan neighborhood of Buraydah (Qassim, KSA) to evaluate its practicality. Scenario analyses are conducted to appraise the economic viability of different management actions for establishing ELL. The study results reveal that conventional ALC can reduce the infrastructure leakage index from around 20 to 7.28, and an additional 43% decrease can be economically achieved by implementing pressure management and control measures on the homeowner side. Environmental valuation analysis demonstrates that upgrading the effectiveness of ALC with a small increase in water prices could further improve the ELL. [ABSTRACT FROM AUTHOR]

This paper presents a practical method for estimating the volume of apparent losses in water supply systems, particularly in a developing country context, so that real losses can be calculated from the volume of nonrevenue water (NRW). The method employs the fact that almost all apparent losses reach wastewater treatment plants (WWTPs). The volume of apparent losses can be estimated through establishing a water and wastewater balance using routine measurements of WWTP inflow and routine data of billed consumption. The water and wastewater balance was applied in the water supply system of Sana'a, Yemen, so NRW components were estimated. Sensitivity and uncertainty analyses show that all sources of the errors are small apart from the level of accuracy of measuring the WWTP inflow, and this accuracy can be practically improved. Other parameters and variables are relatively insensitive. The paper discusses the advantages and limitations of the suggested alternative method compared with the other NRW assessment methods. [ABSTRACT FROM AUTHOR]