The recent implementation of Flood Re to guarantee flood cover for households in the UK has led to an increased interest in the flood risk to insurance company portfolios. Hydro-GIS Ltd were engaged by Axa Art to undertake hydrological field surveys to provide a detailed assessment of the flood risk at six sites which had been flagged up as having the highest risk of the whole portfolio when using a desk-based classification with standard “off the shelf flood” risk mapping products.
The surveys identified that only one of the sites remained at high risk and three were considered a moderate risk given they had experienced some flooding in the past but had since included flood alleviation measures. Of the two remaining sites identified by the surveys as low risk, one was located halfway up a hillside some 50m in altitude above the small stream to which the flood risk at the site would be attributed.
This highlights the potential degree of inaccuracy from the desk based risk mapping products and the benefit of field surveys to give a fuller assessment of flood risk.