A sewer flood risk map of the Anglian Water region is being created by the Wastewater Consultancy team of RPS. The highly accurate 3D digital map showing land elevation has been created using LiDAR data collected by Bluesky’s aircraft mounted laser sensors. The region-wide study of sewer flood risk, at property level, will allow Anglian Water to assess the impact of future changes, such as climate change, growth and urban creep.
“The Bluesky data has been used to complete the catchment coverage for approximately 60 percent of the entire Anglian Water drainage area relating to the sewer network,” commented Alastair Gorst, Team Leader at RPS. “While flooding from sewers is a rare occurrence, more extreme weather events, aging infrastructure and a growing demand on the network can all contribute to incidents. It is therefore essential that we understand the risk, and, through the use of high quality data such as the Bluesky LiDAR, model potential impacts.”
The project, currently in its preliminary stages, originally considered a lower, coarser point density Digital Terrain Model (DTM) to complete cover of the study region, but RPS concluded that this represented a significant increase in risk. The Bluesky LiDAR was tested for a specific catchment area, and the assessment outcomes were found to be significantly improved compared with other data sources. Complementing data from other sources, including Environment Agency LiDAR, the Bluesky data is now RPS’s preferred solution.
The Bluesky LiDAR data is being used by RPS to undertake assessments of overland flood risk from the sewer network. Using InfoWorks ICM (Integrated Catchment Modelling) software, RPS can model both above and below ground elements of catchment to accurately represent and simulate sources of flooding and flow paths, to assess a variety of events and scenarios to understand the potential impact.
RPS has worked with Anglian Water for a number of years, securing the first fully integrated wastewater modelling framework. RPS supplies support and consultancy services for modelling, flow and asset surveys and, using the Bluesky LiDAR data, will assist in the creation of 100 percent model coverage for the Anglian Water region.
Anglian Water is the largest water and water recycling company in England and Wales by geographic area. Serving a region that stretches from the Humber to the Thames estuary and from Buckinghamshire to Lowestoft, Anglian Water supplies and transports water across an area covering 27,500 square kilometres. 11,833 kilometres of water and sewer pipes transect this region, serving more than six million domestic and business customers.