In the past decade, there have been unprecedented changes in the fields of sensor technology, satellite missions, modeling and applications to benefit society. Small satellite systems are shifting observational paradigms to more rapid revisits, higher resolutions and ever-increasing volumes of data. The commercial sector has launched hundreds of satellites and companies are now in the business of understanding the water cycle. Massive amounts of data are available and can be ingested into data assimilation models to better understand the influence any particular part of the water cycle. Machine Learning and Artificial Intelligence has broadened our capability to exploit multiple types of Earth observation data within complex modeling systems. With the exponential growth of cell phones, there are potentially billions of people everywhere who can use their smartphones to access water information.