Why do the Risk of Flooding from Rivers and Sea (RoFRS) and Risk of Flooding from Surface Water (RoFSW) Web Map Services not display?

Created: 28/01/2025 Updated: 28/01/2025

Due to the size and complexity of these datasets, a display limit has been set to ensure the data is usable and to ensure availability. Both datasets benefit from a 2-metre square grid scale.

Web Mapping services have been set to 1:50,000 in the <MaxScaleDenominator> attribute.  The services will only be visible from the 1:50,000 scale range.  As maps from a Web Map Service may be viewed on arbitrary displays rather than on paper, the values used are the scale denominators relative to a common display pixel size. Consequently, end client software may interpret the request differently. 

If the data is only displaying at a larger scale (e.g. 1: 20,000), it is suggested users set the Coordinate Reference System to EPSG:27700 – OSGB36 / British National Grid.

More information can be found by downloading the ‘OpenGIS Web Map Service (WMS) Implementation Specification' from the OGC’s WMS publications.