We invite people to join us in a pan-European experiment of Climate Impact Model Intercomparison, using the guide-lines from Krysanova et al. 2018, on model calibration/evaluation for more trustworthy hydrological modelling under climate change. The initiative runs under the umbrella of ISI-MIP, JPI/ERA4C Aquaclew and will make use of new climate data from the C3S at ECMWF