Flood risk and flood resilience of wastewater assets
Eccleston, P.1, Rhodes, K.2 and Clark, A.1, 1JBA Consulting, UK, 2Anglian Water Services Ltd, UK
(free)
Abstract Many wastewater assets critical to our way of life are at risk of service failure due to flooding, and this risk is predicted to increase as a consequence of climate change. This paper describes an Anglian Water Services project to identify and prioritise flood risk to 8000 water and wastewater assets, and to prepare a business plan to manage flood risk and maintain services to customers and the environment. The frequency and depth of fluvial, pluvial, tidal and groundwater flooding were assessed using flood map data. The consequences of service measure failures and changes in risk due to increased river flows and rainfall intensity under climate change were assessed. A generic flood resilience/resistance identification and costing model was developed taking into account asset type, depth, extent and source of flooding. Finally, 240 at-risk sites were visited to undertake a preliminary flood risk assessment and refine the scope of interventions. The investment need and intervention were considered within an investment optimisation engine to determine an optimal cost beneficial programme for flooding resilience investment in AMP6.
Keywords: Climate Change, Flooding, Flood Risk Management, Flood resilience, Wastewater Pumping Stations, Wastewater Treatment.
Introduction Anglian Water Services (AWS) assets can be at risk from flooding due to Pluvial, Fluvial and Coastal inundation. If a site is flooded there can be an unplanned loss of service such as loss of wastewater facilities or water supply interruption. This paper describes the two phases of the project to identify the flood risk and necessary interventions, leading to an optimal cost beneficial programme for flooding resilience investment in AMP6. Phase 1 key activities were to:
- Review of current flood risk and climate change flood risk to AWS’ non-infrastructure, above ground operational assets for a range of flooding types and return periods
- Outline the potential cost of providing Flood Resilience to all affected assets.
Phase 2 key activities: Site visits to higher risk sites to develop a more detailed understanding of the risk posed and to identify an appropriate solution (such as flood proof doors, walls or embankments).
