Long term average (LTA) Effective Precipitation (Peff) for the European domain at 1 km spatial resolution for the period 1981-2010. The Peff estimate is based on E-Obs precipitation records and a merged AET estimate based on the Budyko method and satellite estimates. The LTA Peff data set i part of a series of gridded datasets established in the TACTIC project for estimating Potential Groundwater Recharge (GWRpot). The data available are AET, Effective precipitation (Peff=Precipitation-AET), Groundwater Recharge coefficient (Rcoef defined as the ratio: Peff / GWRpot ) The Potential Groundwater Recharge GWRpot = (Precipitation-AET)*Rcoef. The TACTIC series of gridded datasets for estimation of GWRpot included two versions of Peff. The current dataset is the Peff_biacorr= (Precipitation-AET)*1.26, adjusted to other Peff estimates from seven national pilots in Europe. The other is Peff = Precipitation-AET. Urban areas are masked out and not represented in the gridded dataset. All units are mm/year for the period 1981-2010.