Licences that widen access to technologies for the processing of critical minerals should also safeguard water (see R. Arezki and G. Rota-Graziosi Nature 655, 302–305; 2026). Without such provisions, the proposed pooling of processing-related patents could spread technological benefits but leave water risks concentrated in producing regions. An analysis of 32 geological resources indicates that mining them to meet future demand will require considerably more water, intensifying existing regional constraints (K. Islam et al. Science 387, 1214–1218; 2025).