Leakage in water distribution systems is an important issue which is affecting water companies and their customers worldwide. It is therefore no surprise that it has attracted a lot of attention by both practitioners and researchers over the past years. Most of the leakage management related methods developed so far can be broadly classified as follows: (1) leakage assessment methods which are focusing on quantifying the amount of water lost; (2) leakage detection methods which are primarily concerned with the detection of leakage hotspots and (3) leakage control models which are focused on the effective control of current and future leakage levels. This paper provides a comprehensive review of the above methods with the objective to identify the current state-of-the-art in the field and to then make recommendations for future work. The review ends with the main conclusion that despite all the advancements made in the past, there is still a lot of scope and need for further work, especially in area of real-time models for pipe networks which should enable fusion of leakage detection, assessment and control methods.

Regular as-built surveys have become a necessary input for building information modelling. Such large-scale 3D data capturing can be conducted effectively by combining structure-from-motion and unmanned aerial vehicles (UAV). Using a RTK-GNSS equipped UAV, 22 repeated weekly campaigns were conducted at two altitudes in various conditions. The photogrammetric approach yielded 3D models, which were compared to the terrestrial laser scanning based ground truth. Better than 2.8 cm geometry RMSE was consistently achieved using integrated georeferencing. It is concluded that the RTK-GNSS based georeferencing enables reaching better than 5 cm geometry accuracy by utilising at least one ground control point.

This paper presents a real time water supply system hydraulic and quality modeling framework that is applied in a case study. The simulated quality parameters include age, traced water source, temperature, pH, hardness and free chlorine.A full-scale and well-calibrated hydraulic model of the whole water supply system is built using an extended version of EPANET, allowing storing and restoring the state of plug flow in links. Once an hour, the simulator is updated with the previous hour's hydraulic and quality state from the utility's supervisory control and data acquisition (SCADA) system and a simulation is performed. The results are stored both in GeoJSON format for geographic information systems (GIS) and in a relational database for later use. Some results are presented to the general public in a geographically aggregated form over a web user interface and as open data using Representational State Transfer (REST) web service interface

Several methods have been developed so far which attempt to detect leaks in water distribution systems by taking into account pressure (and possibly other available) measurements. As in many previous approaches, the leak detection problem is formulated and solved here as an inverse problem with unknown leak areas being the calibration parameters. However, unlike the previous approaches, a stochastic (rather than deterministic) leakage detection methodology is developed and used here. This methodology is based on the Shuffled Complex Evolution Metropolis (SCEM-UA) algorithm and is capable of estimating the posterior probability density functions of unknown leak areas in a single model run. Baring in mind the accuracy of similar leak detection approaches, it is believed that the stochastic context used here is more appropriate than the deterministic one used before. To achieve the above goal, the Epanet2 hydraulic network modelling software is linked to the SCEM-UA software in the Matlab programming environment. The SCEM-UA algorithm parameters are tuned to achieve an effective and efficient search for unknown leak areas. The methodology developed is tested on two literature case studies. This paper was presented at the 8th Annual Water Distribution Systems Analysis Symposium which was held with the generous support of Awwa Research Foundation (AwwaRF).

Digital construction is expected to reduce the high volume of waste and the labour shortage in the construction sector. The properties of hardened concrete used in 3D printing depend on numerous parameters within the manufacturing process. This study collected data using 208 specimens to measure the effect of the loading direction relative to the printing direction on the strength characteristics of printed concrete. The compressive strength was not significantly affected by the directions, but showed a 30% reduction from mould-casted strength due to lesser amount of compaction in the printing process. Flexural tensile strength showed a 14% reduction in one direction, possibly caused by heterogeneity due to the use of extrusion head with a 35% smaller diameter than the width of the layer. Splitting tensile strength was 14% lower when split between the printed layers. Splitting tensile strength is possibly 5% higher when PP fibres are oriented favourably.

A simple graphical tool was developed, that finds the optimal combination of pumps and their rotational speeds for all possible working points for a pump battery. The tool was integrated into EPANET as well as EPA SWMM simulation packages. The tool allows us to analyse and optimize operation non-identical parallel pumps with different minimum and maximum frequencies for all possible working points. Pump characteristics and efficiency curves can be given in tabular format or as analytical functions of flow. Degradation of pump efficiency at lower rotational speed is taken into account, as well as motor and variable speed drive efficiencies at partial loads. The optimal solution provided by the tool was compared to measurements in two case studies. Our case studies showed 6.1–8.5% reduction in energy usage using the optimal parallel pumping control strategy compared to the currently used strategy, where all running pumps have the same frequency.