What is the Citizen River Habitat Survey and why is it important?

The citizen River Habitat Survey (cRHS) is a method that enables river enthusiasts and citizen scientists to get involved with recording and assessing the physical structure and characteristics of rivers and streams. Most rivers in the UK are failing ecological standards set by law and only 14% are considered in ‘Good Ecological Status’.

The reason is a combination of water and habitat quality issues. Although water quality has improved in the past 40 years, the physical structure of our rivers and the habitats they provide (e.g. gravel bars, deep pools, tree shading) has not.

To improve the ecological and visual quality of our rivers, we need to start restoring the physical habitat and remove some of the engineering structures we introduced (e.g. weirs, artificial banks, concrete river beds etc). To do so, we need first to assess the habitat quality of rivers and identify the pressures impacting them. We can then develop strategies for improving and restoring our waterbodies.

Development of cRHS

The citizen River Habitat Survey was developed by the River Restoration Centre (RRC) in 2021 with support from Natural Resources Wales. It is based on River Habitat Survey (RHS) method. RHS is an established standard methodology for characterising and assessing the physical character of freshwater streams and small rivers. The methodology has been used across the UK since 1994. The data are used to calculate a series of quality scores relating to the hydromorphological condition of rivers that can support Water Framework Directive assessment including: Habitat Modification Score, Habitat Quality Assessment scores, Riparian Quality Index and River Habitat Quality index.


The data is widely used in the environmental sector to support planning, management and river restoration and it was applied towards assessing the state of the environment in Wales, the implementation of the Water Framework Directive and prioritising for river restoration.

RRC has adapted the RHS for citizen science (cRHS) so that it can be applied by members of the public after attending a short training course. The cRHS involves recording habitat features, engineered structures and other pressures and taking measurements, photos and videos.

Find cRHS information