Resilient Water Supply - Feddback from validation and demonstration in partner cities WP5.2

Abstract

PREPARED Enabling Change gathered urban utilities in Europe and worldwide to develop advanced strategies in meeting the upcoming challenges for water supply and sanitation brought by climate change. The project linked comprehensive research with development programmes in these utilities. The PREPARED vision provided significant synergistic opportunities that the utilities can utilise to improve their preparedness for the ongoing changes related to the provision of water supply and sanitation. Water supply systems comprise the whole chain from water source (groundwater and surface water), to treatment and distribution, and climate change will impact all elements of this chain. River floods are the most common natural disaster in Europe, and flood damage is expected to increase in the next decades. Among the assets at risk are water wells, and flooding of wells may obstruct the supply of safe and sufficient water in affected areas. More frequent, more rapid and more severe raw water quality depreciation events caused by heavy rain incidents are expected. Also, higher temperatures and severe droughts may significantly change the raw water quality with negative impact on the water treatment plants and water supply networks. Water supply systems have to adapt to changes in raw water qualities, such as increased concentrations in natural organic matter, microbiological substances and low density particles. PREPARED work package 5.2 specifically addressed water supply systems and aimed at developing technologies and practices that make these systems resilient to climate and other changes. Work included: - development of practical guidelines to make water well fields ‘flood proof’(del. 5.2.1), including an overview of methods to detect and repair leaks in wells (del. 5.2.3) - development of design and operational protocols for aquifer storage and recovery (ASR) systems, based on experiences and recent developments in Europe and worldwide (del. 5.2.2). ASR enables the subsurface storage of water to balance periods of high water supply with high water demands; - assessment of current approaches to handle climate change related raw water quality changes, and options to make multi-barrier treatment systems climate robust (del. 5.2.4/ 5.2.5), and - development of remedial actions to prevent adverse effects of re-growth in networks at higher temperatures (del. 5.3.6). The outcomes of PREPARED are to be used as input for the planning and rehabilitation programmes of the participating cities. This report provides 6 examples of how results from work package 5.2 were taken up by partner cities and implemented in their operation and planning. It is our sincere hope that these examples inspire other actors of the water sector in Europe to help make their systems resilient to climate change.