California's Santa Clara Valley, widely known as the Silicon Valley, manages its water resources admirably, integrating surface water, groundwater, artifi cial recharge, waste-water treatment, imported water, water conservation and public participation. As India seriously tackles its water challenges, the Silicon Valley's case history provides insights into how citizens of a hydrological basin may take control of their indigenous water resources based on an understanding of the essential attributes of hydrological systems, and drawing upon the best available science to achieve sustainable management. This case history also highlights the fact that even with the most sophisticated integrated water management, there are defi nite limits to the extent to which indigenous resources can satisfy water demands.