The River Condition Assessment (RCA) is a field and desk-based survey used to assess the habitat and morphological quality of rivers. River morphology describes the physical and hydrological processes in a river which defines its physical characteristics, For example, erosion and depositional features. The physical characteristics of a river influence the habitats that can establish within a river.

The Modular River (MoRPh) survey is the field element of the RCA. This survey is used on at least 20% of the survey area to systematically record all physical features and habitat types present. As well as any artificial features which may be impacting river flows. This is

because artificial features can impact the natural function of rivers and remove the diversity of physical features and habitats.

The desk study element is a reach-based study identifying the hydrogeomorphological river type. In combination, the field and desk study gives each individual stretch of the river an RCA score of either: 1= Good, 2= Fairly Good, 3= Moderate, 4= Fairly Poor, 5= Poor.

The RCA can be used as part of a Biodiversity Net Gain assessment, to provide either a baseline or uplift assessment of river restoration work.

Rivers Ecology is fully trained and experienced in completing RCA surveys to inform biodiversity net gain assessments and has worked on reach-scale restoration projects as well as completing baseline assessments for large-scale development projects.