This dataset comprises water heights in rivers and adjacent riparian soils for six riparian observatory sites in NE Scotland and NW England. The dataset includes hourly height of soil water table (WT; when depth is below the soil surface), including times of flood inundation (water above the soil surface) and soil water temperature at six positions in each site and the hourly river water stage height. This dataset supports analysis of hillslope to floodplain water table and river flood functions of catchment hydrology and the role of saturation on soil biogeochemistry across climatic and land use gradients. All verified observations are aggregated into a single table (soil_river-_hydrology_uk_riparian_observatories_data.csv), with accompanying metadata (soil_river-_hydrology_uk_riparian_observatories_metadata.csv) describing variable definitions, units, relevant depths of equipment and ground, measurement procedures and context of the soil horizons. Monitoring was carried out as part of the NERC-funded project "Accelerating Nutrient Cycles at the Riparian Land : Water Interface" (NE/V012460/1) investigating riparian zone biogeochemistry across temperate regions. The six riparian observatories of the CARRI project were established to evaluate and extrapolate riparian zone processes controlling C, N and P stocks, mobility and climate change sensitivity. Full details about this dataset can be found at https://doi.org/10.5285/70109fe8-a415-4aeb-8184-d82f7c334fe2