The Central Valley of California is one of the most productive farmlands in the world. To maintain this agricultural productivity, it uses a large amount of surface water and groundwater. The latest droughts in western USA (e.g., 20122015) have drastically increased the amount of groundwater pumping threatening the groundwater sustainability in the valley. Therefore, it is urgent to improve our understanding about the groundwater system for sustainable management of groundwater resources. Monitoring changes in groundwater level and volume with high resolution provides fundamental data for this. Working with five years of the Satellite InSAR (interferometric synthetic aperture radar) surface deformation data covering the entire valley and tens of thousands of wells providing insitu groundwater level data, in this talk, I will present how the modern remote sensing technique can be combined with the traditional wellbased technique to monitor groundwater level and volume with high resolution. I will also discuss how the airborne electromagnetic (AEM) method, which provides a rapid mapping capability to image hydrogeologic structure of the subsurface, can play an important role for this monitoring task.