Future Flows Hydrology (FF-HydMod-PPE) is an 11-member ensemble projections of river flow and groundwater levels time series for 283 catchments and 24 boreholes in Great Britain. It is derived from Future Flows Climate, an 11-member 1-km bias-corrected and downscaled climate projection products based on the SRES A1B emission scenario. River Flows data are at a daily time step: Groundwater Levels data are at a monthly time step. Future Flows Hydrology span from 1951 to 2098. The development of Future Flows Hydrology was made during the partnership project 'Future Flows and Groundwater Levels' funded by the Environment Agency for England and Wales, Defra, UK Water Research Industry, NERC (Centre for Ecology & Hydrology and British Geological Survey) and Wallingford HydroSolutions.