New Zealand’s hydrologists were surveyed to determine what information they believe is lacking and what information they believe is important for more effective management and allocation of New Zealand’s freshwater supply. Two research questions and five qualitative questions related to information needs and water policy were administered to 79 hydrologists through an online survey. The survey identified four factors as both important and lacking to hydrologists: (1) representative models, (2) data for more-advanced models, (3) information on interaction of water with other variables, and (4) information on sustainability of water resources. Five additional qualitative questions supported these findings and identified further areas of concern.