Urgent measures must be taken to ensure that it does not take a generation to muster the necessary political willpower to restore the health of rivers globally, as C. J. Vörösmarty and colleagues suggest (Nature 467, 555–561; 2010). The livelihoods of 60 million people in the developing world depend on river fisheries, and millions more rely on them for food.

Lessons can be learned from Vietnam's positive actions, for example. Its Vu Gia–Thu Ban river basin is used for hydropower development, but rivers have dam-free stretches, designated after strategic environmental assessment with stakeholder participation (see http://go.nature.com/xnbbgr). Developing alternatives to large-scale mainstream dams — including river-bypass systems and micro-hydroelectric power installations for local use — will help to reduce trade-offs between water security and river biodiversity.

The pessimistic prediction of Vörösmarty et al. may well turn out to be correct for large river systems in Asia, Africa and Latin America, where weak governance of water allocation, dam construction and river management frequently overlooks the dependence of riparian communities on ecosystem health (P. Dugan et al. Ambio 39, 344–348; 2010). Investment is needed now to build adaptive capacity and new livelihood opportunities for poor river communities.

We need much more investment of the kind made by the Consultative Group on International Agricultural Research. This group of publicly funded institutions is developing a programme to benefit poor people who depend on aquatic agricultural systems (see http://go.nature.com/g98kLv). This will focus initially on the basins of the Mekong, Zambezi and Ganges–Brahmaputra–Megna rivers.