River Habitat Survey - Survey Details and Summary Results

This record is for Approval for Access product AfA434. "River Habitat Survey (RHS) is the Environment Agency standard for collecting data on the physical character and quality of river habitats across the UK.
This dataset provides survey details and summary results for river habitat surveys carried out from 1994 to present. This dataset is a subset of AfA286 River Habitat Survey.  Since 1994 OVER 21,000 surveys have been carried out in England. The bulk of surveys were carried out between 1994 to 1997 and 2006 to 2008. Surveys are still carried out for specific drivers, for example assessing habitat availability and Water Framework Directive.
For further information on the survey methodology the RHS manual can be downloaded from www.gov.uk. Surveys conducted prior to 2003 should not be compared with surveys conducted after 2003 as survey methodology changed significantly in 2003. River names may be in English, Welsh or Gaelic. 
This dataset no longer contains data owned by Natural Resources Wales (NRW). To request data that relates to Wales please contact NRW.  Dimensions are intended to provide context for these habitat surveys. They should not be used for other purposes.  The following information has been excluded from the survey data supplied to you because there is a risk that we might be disclosing personal data. If a customer has a particular interest in a particular site/survey examples of the type of information we may be able supply are:
• General description of the survey
• Surveyors name
• Weirs/sluices, culverts, outfalls/intakes, dams, abstractions, hydroelectric power
• Where channel is choked by vegetation or a debris dam impeding flow 
• Tipped materials and landfill
• Presence of sewage and pollution
• Gravel extraction

Please note: We have discovered some errors in the HQA in-stream channel vegetation sub-score and the HMS Culverts sub score that users of our data need to be aware of:

1.	In-stream channel vegetation HQA sub-score: This error has now been fixed - all surveys carried out after 12/07/2017 will be correct.  However, stored, historic calculations are not automatically updated.  The error only applies under certain criteria (where present or extensive is entered in Spot-check 11, but spot-check’s 1-10 are not listed as present or extensive for the same vegetation category) and will only affect the HQA sub-score by a few points.

2.	1994 surveys - In-stream channel vegetation HQA sub-score (Submerged vegetation).  No fix in place – all recorded submerged vegetation category entries are excluded from any 1994 surveys.  This error will only impact the HQA scores by 1-2 points

3.	HMS Culvert Score error.  No fix in place.  This error affects sites where a culvert is recorded in a spotcheck(s) and Bank Material, Bank modification and channel substrate are not listed as NK or NV.  This can affect the scores on a much larger scale as our database is failing to add on 50 points per culverted spot-check, that fulfil these criteria. Attribution statement: © Environment Agency copyright and/or database right 2025. All rights reserved.

Tags: RHS, River Habitat Survey, environment, habitat, river channelling, riverside vegetation
Organization: Environment Agency