You Wu, chief executive of Pipeguard Robotics, holds the robot he invented, which he calls Daisy. It travels with the flow in water pipes to detect and gather data on water leaks. But as everyday technologies go, water management is virtually invisible to the general public. One organization that's working to change that is Imagine H2O, a startup accelerator based in San Francisco.

We hear plenty these days about breakthroughs in green energy, robotics and communications. But as everyday technologies go, water management is virtually invisible to the general public. One organization that's working to change that is Imagine H2O, a startup accelerator based in San Francisco. A nonprofit, it provides support to emerging companies working on water problems, helping them find investors and customers. Every year, Imagine H2O hosts a competition to nurture a class of promising water entrepreneurs.