Water distribution networks (WDNs) require large capital investment and ongoing operational costs, resulting in their optimisation being a highly researched field. Despite the benefits tanks bring to networks, most optimisation models omit them as decision variables due to the complexity they can introduce to heuristic approaches. This paper addresses the least-cost optimisation of WDN design and operation through the development and application of the Small-network Configurator for Optimising Pump Energy consumption (SCOPE). The SCOPE algorithm incorporates pipes, pumps and tanks as decision variables and solves the optimisation problem through an iterative approach that pairs EPANET simulation results with subsequent hydraulic calculations to converge on the pumping and storage configuration which yields the lowest energy consumption. The SCOPE output can then be used to seed further optimisation techniques. This approach has been tested on the synthetic Nametown and real-life Dili networks and demonstrated annual cost savings of 10% and 25%, respectively.

Lately, due to overutilization of scarce natural resources such as water, tourist islands have been severely threatened. This is also the case in Santa Cruz Island, the main inhabited island of the Galápagos Archipelago. Therefore, a Multi-Criteria Decision Analysis (MCDA) was carried out with the aim of mitigating the future water crisis. The proposed solutions were evaluated in terms of environmental, technical, economic and social criteria. The results indicate that the ‘best’ alternative for municipality representatives is the option including desalination. However, for the other two groups of stakeholders, the chosen option was the one that combined all the proposed alternatives (greywater recycling, specific demand reduction and rainwater harvesting), except desalination. Conclusions show that for most stakeholders the environment is the most important criteria.

Santa Cruz Island (Galápagos Archipelago), like many other tourist islands, is currently experiencing an exponential increase in tourism and local population growth, jeopardizing current and future water supply. An accurate assessment of the future water supply/demand balance is crucial to capital investment for water infrastructure. This paper aims to present five intervention strategies, which are suggested to solve the future water crisis. The strategies combined include environmentally sustainable options such as rainwater harvesting, greywater recycling and water demand management, as well as desalination. These strategies were evaluated under four population growth scenarios (very fast, fast, moderate and slow growths) by using several Key Performance Indicators (KPI's) including water demand, leakage levels, total costs, energy consumption, rainwater delivered and greywater recycled. Moreover, it also aims to develop a methodology for similar islands, using the WaterMet² modelling approach, a tool for integrated of sustainable-based performance of urban water systems. The results obtained show that by 2044 only a small portion of the future water demand can be covered assuming business as usual. Therefore, desalination seems to be the most viable option in order to mitigate the lack of water at the end of the planning period considering the growth trends. However, strategies comprising more environmentally friendly alternatives may be sufficient, but only under slow population growth scenarios.

Tourism exerts a significant pressure on water resources in tropical islands and is the main reason for the increase in water demand. This paper analyzes and quantifies water demand in Santa Cruz, the most populated island of Galápagos Archipelago (Ecuador). The data for this study were collected from a survey of 374 households in the two main settlements, Puerto Ayora and Bellavista. Water supply from different sources was assessed and compared with domestic and tourist water use. The study revealed that the daily average water demand per capita differs 40% between the settlements, mainly resulting from a difference in water tariffs. The tourist sector was also confirmed as the major consumer, accounting for 55% of the total water demand. Lastly, implementation of proper water demand management measures is essential in order to develop consumers’ awareness and sustainable tourism.

Intermittent water distribution systems are a stark reality in developing countries. Puerto Ayora, the centre of tourism of the Galápagos Archipelago, is not an exception, with its population and tourists suffering from scarce water resources. However, the extreme per capita consumptions, well above those in 24/7 supply situations in many other countries, contradict the (sense of) scarcity. In this study, 18 water meters were installed and a water-appliance diary was carried out in 15 randomly selected households in Puerto Ayora. The aim was to determine and analyse domestic water consumption, as well as the diurnal patterns, also by verifying per capita figures ranging from 40 to 380 litres per capita per day from a previous study. Also, the aim was to find a correlation between the consumption and schedules of distribution conducted by the municipality. The paper also elaborates on typical household appliances used, and gives an insight about a wide range of domestic demands in a predominantly water-scarce area. The conclusions indicate no influence of the specific intermittency patterns to the specific demand, but rather a wide range of different lifestyles, the possible presence of informal accommodations and excessive wastage.

This paper describes the vision behind and the mission of the Maxeler Application Gallery (AppGallery.Maxeler.com) project. First, it concentrates on the essence and performance advantages of the Maxeler dataflow approach. Second, it reviews the support technologies that enable the dataflow approach to achieve its maximum. Third, selected examples of the Maxeler Application Gallery are presented; these examples are treated as the final achievement made possible when all the support technologies are put to work together (internal infrastructure of the AppGallery.Maxeler.com is given in a follow-up paper). As last, the possible impact of the Application Gallery is presented and the major conclusions are drawn.