The Hydrological Information and Prognosis System (HIP) was established by the Danish Agency for Data Supply and Efficiency (SDFE) in collaboration with municipalities, regions, and state authorities as part of the Joint Public Digitalisation Strategy. HIP provides a common, open data infrastructure for climate adaptation by integrating terrain, water, and climate data into a single, accessible platform. The HIPdata.dk portal allows users to access a wide range of hydrological datasets and model simulations, including national groundwater calculations on a 100-metre grid and refined historical calculations at a 10-metre grid using machine learning techniques. Long-term projections extend up to the year 2100, helping decision-makers understand future risks of high groundwater and flooding. The portal connects raw terrain and climate data with advanced hydrological modelling, ensuring coherence across scales for planning, water management, flood protection, and environmental safeguarding.