An impact assessment methodology for urban surface runoff quality following best practice treatment

The paper develops an easy to apply desk-based semi-quantitative approach for the assessment of residual receiving water quality risks associated with urban surface runoff following its conveyance through best practice sustainable drainage systems (SUDS). The innovative procedure utilises an integrated geographical information system (GIS)-based pollution index approach based on surface area impermeability, runoff concentrations/loadings and individual SUDS treatment performance potential to evaluate the level of risk mitigation achievable by SUDS drainage infrastructure. The residual impact is assessed through comparison of the determined pollution index with regulatory receiving water quality standards and objectives. The methodology provides an original theoretically based procedure which complements the current acute risk assessment approaches being widely applied within pluvial flood risk management

Barriers to transformative adaptation: Responses to flood risk in Ireland

Barriers to climate change adaptation have received increased attention in recent years as researchers and policymakers attempt to understand their complex and interdependent nature and identify strategies for overcoming them. To date however, there is a paucity of research on barriers to transformative adaptation. Using two case studies of flood risk management from Ireland we identify and characterize barriers to transformative adaptation. Qualitative semi-structured interviews were conducted with key stakeholders connected to proposed transformative strategies in Skibbereen, County Cork and Clontarf, County Dublin. Across both case studies, where transformative strategies failed to materialize, we highlight three significant barriers that impede transformation including: (i) social and cultural values, particularly place attachment and identity; (ii) institutional reliance on technical expertise which fails to look beyond traditional technocratic approaches and; (iii) institutional regulatory practices. Findings illustrate that where social or institutional barriers emerge, transformation may more likely succeed through a series of incremental changes. This research has practical implications for future adaptation planning as facilitating transformation through incrementalism requires flexible adaptation strategies that are responsive to changing social values over time. While focused on flood risk management, our findings have applicability for other sectors adapting to climate change

Urban surface water pollution problems arising from misconnections

The impacts of misconnections on the organic and nutrient loadings to surface waters are assessed using specific household appliance data for two urban sub-catchments located in the London metropolitan region and the city of Swansea. Potential loadings of biochemical oxygen demand (BOD), soluble reactive phosphorus (PO4-P) and ammoniacal nitrogen (NH4-N) due to misconnections are calculated for three different scenarios based on the measured daily flows from specific appliances and either measured daily pollutant concentrations or average pollutant concentrations for relevant greywater and black water sources obtained from an extensive review of the literature. Downstream receiving water concentrations, together with the associated uncertainties, are predicted from derived misconnection discharge concentrations and compared to existing freshwater standards for comparable river types. Consideration of dilution ratios indicates that these would need to be of the order of 50–100:1 to maintain high water quality with respect to BOD and NH4-N following typical misconnection discharges but only poor quality for PO4-P is likely to be achievable. The main pollutant loading contributions to misconnections arise from toilets (NH4-N and BOD), kitchen sinks (BOD and PO4-P) washing machines (PO4-P and BOD) and, to a lesser extent, dishwashers (PO4-P). By completely eliminating toilet misconnections and ensuring misconnections from all other appliances do not exceed 2%, the potential pollution problems due to BOD and NH4-N discharges would be alleviated but this would not be the case for PO4-P. In the event of a treatment option being preferred to solve the misconnection problem, it is shown that for an area the size of metropolitan Greater London, a sewage treatment plant with a Population Equivalent value approaching 900,000would be required to efficiently remove BOD and NH4-N to safely dischargeable levels but such a plant is unlikely to have the capacity to deal satisfactorily with incoming PO4-P loads from misconnections

Why it takes an 'ontological shock' to prompt increases in small firm resilience : sensemaking, emotions and flood risk

This article uses a sensemaking approach to understand small firms’ responses to the threat of external shocks. By analysing semi-structured interviews with owners of flooded small firms, we investigate how owners process flood experiences and explore why such experiences do not consistently lead to the resilient adaptation of premises. We, conclude that some of the explanation for low levels of adaptation relates to a desire to defend existing sensemaking structures and associated identities. Sensemaking structures are only revised if these structures are not critical to business identity, or if a flood constitutes an ‘ontological shock’ and renders untenable existing assumptions regarding long-term business continuity. This article has implications for adaptation to the growing risk of flooding, climate change and external shocks. Future research analysing external shocks would benefit from using a sensemaking approach and survey studies should include measurements of ‘ontological’ impact as well as material and financial damage. In addition, those designing information campaigns should take account of small firms’ resistance to information that threatens their existing sensemaking structures and social identities

Decision Support Tool for energy-efficient, sustainable and integrated urban stormwater management

[EN] The use of Sustainable Drainage Systems (SUDS) to manage urban runoff and contribute to environmental and landscape improvement is now widely known, but its application is still limited in many regions, like in Mediterranean countries. In addition, there is a lack of Decision Support Tools that consider all their benefits in the decision making process in a clear and integrated holistic way. In this paper, the (ESTORMED)-S-2 Decision Support Tool is presented. This tool analyses the impact of stormwater management in the urban environment and introduces energetic and environmental criteria in the decision making process. Therefore, it aims to fill in the existing "gap" between SuDS manuals and guidelines and regional and local decision makers, since it quantifies SuDS benefits and includes them in the comparison of different stormwater scenarios. Finally, the results of applying this tool to compare drainage infrastructures in a real urban development are described. (C) 2016 Elsevier Ltd. All rights reserved.The E2STORMED project (Reference: 1C-MED12-14), within which the Decision Support Tool described in this paper has been developed, was funded by the MED Programme of the European Union. Authors would also like to express their gratitude to the E2STORMED project partners for their assistance and collaboration in this work.Morales Torres, A.; Escuder Bueno, I.; Andrés Doménech, I.; Perales Momparler, S. (2016). Decision Support Tool for energy-efficient, sustainable and integrated urban stormwater management. Environmental Modelling & Software. 84:518-528. doi:10.1016/j.envsoft.2016.07.019S5185288

Urban resilience:two diverging interpretations

This paper uses two diverging interpretations of resilience to review and assess current UK policies for urban resilience. Both developed in scientific studies, the first interpretation is based on a mechanistic model of systems that can recover their original state after shocks, and the second is based on an evolutionary model enabling adaptation to disturbances. The literature review demonstrates that at present urban resilience is predominantly associated with the former. By contrast, only few policies and studies are inspired by the latter, although this is better suited to analyse dynamics of urban adaptation and manage cities accordingly. The contribution of this paper to an understanding of urban resilience is therefore twofold. First, an identification of the long-term consequences on the built environment associated with each model is provided, with the mechanical model ultimately hindering adaptation. Second, some approaches to generate effective responses to environmental and societal change are identified. Ultimately, this paper emphasises that the idea of a resilient city is fit for this age characterised by uncertainty, albeit it requires the recognition within planning practice that urban adaptation cannot be attained with current methodologies, and that much can be learned from theories on the resilience of ecosystems.

Assessing the value of intangible benefits of property level flood risk adaptation (PLFRA) measures

© 2015, Springer Science+Business Media Dordrecht. Studies in the UK and elsewhere have identified that flooding can result in diverse impacts, ranging from significant financial costs (tangible) to social (intangible) impacts on households. At the same time, it is now clear that large-scale flood defence schemes are not the panacea to flood risk, and there is an increasing responsibility on property owners to protect their own properties. Hence, there is an emerging expectation for homeowners to take action in the form of investing in property level flood risk adaptation (PLFRA) measures to protect their properties. However, hitherto the level of uptake of such measures remains very low. The tangible financial benefits of investing in PLFRA measures are generally well understood and have been demonstrated to be cost beneficial for many properties at risk from frequent flooding. Importantly, these estimates tend to take little account of the value of the intangible benefits of PLFRA measures and therefore may be under estimating their full benefits. There remains a need to develop an improved understanding of these intangible benefits, and this research sets out to bridge this knowledge gap. Based on a synthesis of the literature, the contingent valuation method was selected as a means to value intangible impacts of flooding on households. A questionnaire survey of homeowners affected in the 2007 flooding was employed to elicit willingness to pay (WTP) values to avoid the intangible impacts of flooding on their households. The analysis of the questionnaire survey data revealed that the average WTP per household per year to avoid intangible flood impacts was £653. This therefore represents the value of the intangible benefits of investing in PLFRA measures and is significantly higher than previously estimated. This research builds on previous research in suggesting a higher value to the intangible impacts of flooding on households by assessing wider range of intangible impacts and focussing on more experienced individuals. Furthermore, the research indicates that factors which influence the WTP values were principally stress of flood, worrying about loss of house values, worrying about future flooding and age of respondents, with income showing a weak correlation. The establishment of a new value for the intangible impacts of flooding on households in the UK is helpful in the domain of flood risk management when evaluating the total benefits (tangible and intangible) of investing in flood protection measures, thus providing a robust assessment for decision-making on flood adaptation measures at an individual property level