Increasing the resilience of urban areas to extreme precipitation: Are the residents ready?

Abstract

Water challenges the livelihood of all living beings through its scarcity and its abundance. Due to climate change these extremes will intensify in the future. As mankind continues to cluster in economic centre points, housing areas as well as infrastructure increases. This situation forces the water to run off rather than infiltrate. Inundated areas place a threat to health and mankind will be forced to increase the resilience in urban areas. Adaptation to more extreme weather situation on private terrain is necessary as private space contributes 50% of the area. In order to stimulate inhabitants to adapt different measures it is essential to get an idea of their receptivity. The receptivity model of Jeffrey and Seaton (2009) offers a framework to understand with which of the 4 A’s (Awareness, Association, Acquisition and Application) residents are struggling most. A sequential mixed method of combining questionnaires and focus groups was used to collect data on residents’ receptivity and perceived effectiveness of potential rainproof measures. Additionally, the hydrologic expected effectiveness of selected rainproof measures was analysed with help of the Adaptation Support Tool and compared to the perceived effectiveness. Although residents are developing all 4 A’s simultaneously to different extend and speed, it appears that residents are struggling with Awareness. Their experience with flooding and water damage reveals awareness of the issue itself; however, hesitation to implement countermeasures was noticed. The awareness of solutions is missing for more than half of the respondents. The association with their own agenda and recognising the benefits is not yet widespread among residents. The acquisition requirement of receptivity – the knowledge about implementation, operation and maintenance – is missing. It is evident that the application requirement cannot be accomplished as acquisition is absent. Residents demand additional information. The development of the 4 A’s, specifically Association and Acquisition, require more attention. Residents recognise their own responsibility for the private lot, but also shared responsibility and thus community actions are expected. Residents insist that the municipality and Waternet fulfil their tasks within their responsibilities. Transparency and communication with residents are important features, whereby provision of tailor-made advice has high importance. Recognising responsibilities and also dependencies between different stakeholders as well as knowledge requests reveal lacking receptivity and further encouragement is required. Frontrunners can hereby play an important role. The effectiveness of countermeasures is an important consideration for increasing resilience. Evidently respondents indicated rainwater barrels as possible measure to temporarily store water. Green roofs were also well known. The perceived effectiveness scored relatively high for all temporary water storage measures. The Adaptation Support Tool (AST ) calculated effectiveness between 2% and 42%, where this is a percentage of a 60mm precipitation storage target. The highest effectiveness of 42% is achieved by intensive green roofs, whereas the costs are relatively high. A rainwater pond on the other hand has low investment and maintenance costs and scored an effectiveness of 22%. Green gardens reveal higher costs, but also greater effectiveness. It is expected that all gardens already have some green spaces and a simple intervention as reducing tiles could contribute up to 30% of the target. The calculations demonstrate that none of the measures could achieve the target alone. A combination is required, whereby the order of implementation can be guided by their effectiveness and costs. For improving receptivity of residents, several points should be considered. First of all connect residents with similar issues, they possibly motivate each other and develop an urge to action. Tailor-made information improves information distribution. Residents are reluctant due to unfamiliarity with alternatives for their specific situation. It is also important that residents are aware of the effectiveness and the costs of measures for when they need to chose. The AST calculations give insight in the effectiveness and costs of measures. Transparency of tasks, responsibilities and choices of the municipality, Waternet and Amsterdam Rainproof could provide a positive mindset towards the implementation of rainproof measures. Communication about (possible) barriers might be helpful in order to prepare residents. It is important that the municipality promotes climate adaptation throughout the entire legal and organisational levels.