The key to success in the 21st century will be adaptation to a changing hydrological regime for the energy-water nexus. The first of the three constraints identified in this paper is insufficient data and information. It is one thing to know this is true. It is another thing to do something about it. It is my opinion that the regions of the world that will leave the greatest endowment to the next generation are those that invest in water information management as a strategic asset.