Online GIS maps developed in 2018, by excluding /deleting unsuitable areas from the Environment Agency’s floodplain layer. Unsuitable areas included urban areas, major infrastructure, and existing managed realignment sites.
This data layer should only be viewed as a high-level indication where managed realignment may be feasible. Sites are not ranked according to their suitability, nor does the layer indicate whether land is actually available for intertidal habitat creation (e.g. landowners may not want to sell). Whilst a validation exercise showed that using the Floodplain 3 data layer would generally lead to the identification of sites which could support mostly intertidal habitat if they were breached, the actual habitats achieved would depend on the regional and site conditions. Further investigations should be undertaken once a site has been judged as being of potential interest. Also, the larger sites identified are unlikely to be suitable for intertidal habitat creation across their entirety, for example due to potential difficulties relating to getting water to all areas of the site, or because very large sites may have undue impacts on the adjacent estuary. Thus, in reality, large sites will likely need to be sub-divided, and those areas closer to the shoreline preferentially targeted.