The survey classifies hydromorphological condition using WFD nomenclature: High, Good, Moderate, Poor, Bad. Its typical use is to support the designation of high ecological status sites. Other applications of the RHAT method include assessing hydromorphological pressures, determining enhancement/restoration works required and pre-/post- works conditions for specific projects. Research and Operations teams based in Inland Fisheries Ireland have been using the RHAT methodology to assess habitat condition across various sites and catchments of interest.The OPW Environmental River Enhancement Programme (EREP) uses the RHAT methodology to collect hydromorphology data on a catchment-wide basis using a Survey123 RHAT form. Further detailed information on these surveys is available in the annual reports, which can be found on the website.
This application uses data which can be downloaded from the Water Framework Directive Hydromorphological Status data page. Map contains data produced by the Environmental Protection Agency.

For more information on the RHAT methodology see the following references:

RHAT Training Manual (daera-ni.gov.uk) ISBN: 978-1-907053-65-8

River Habitat Survey (Environment Agency 2003, Raven et al., 1998)