Long term planning for the water supply system of the Metropolitan Area of Amsterdam under new water saving regimes of the retail customers

Abstract

The centralized drinking water supply system of the Metropolitan Area of Amsterdam, operated and owned mainly by Waternet, has high performance indicators and satisfies the full demand for water in the urban grid and surrounding areas on a full cost recovery basis. Social and technological developments, stemming mainly from (i) the increasing world-wide concern about the sustainability of resources, water scarcity and the effects of climate change, (ii) concepts related to integrated urban water management with a target towards sewage load reduction and rain water retention, and (iii) innovation in housing appliances and waste-water treatment technology, suggest that the current regime of drinking water demand of retail customers could change. A decrease of water demand concerns the water utility, that is operating a system in under-capacity and is currently working on a Long-Term Vision for their water supply system. The future seems highly uncertain and it is essential to understand (i) how and by whom water saving could be induced in an area of abundant water resources like the Metropolitan Area of Amsterdam and (ii) what kind of effects a further decrease of water demand could bring about. Standard Policy Analysis techniques are applied to address this issue and the approach is largely qualitative. Desk study and interviews are conducted to collect information and data that are systemized and further processed through uncertainty and systems analysis to supply an answer to the above. The anticipated changes that could lead to water saving –drivers of water saving– are clustered in categories for supplying clarity and are, then, classified according to their potential effect and uncertainty. Stakeholders and their actions that could induce water saving are also identified. The system is decomposed into embedded subsystems in order to identify potential effects on each one, and mitigating alternatives are discussed after examining the available practices for maintaining a high performing water supply system. The analysis supplies insights on the type of information that Waternet needs to seek in order to perform educated explorations about the future, as well as on how this could be achieved. The outcome of the research can be utilized towards this end and towards developing further the Long-Term Vision of the water supply system. However, further research is necessary in order to make elaborate quantitative estimations in this direction.