Yes: Gravimetric measurements from GRACE have been a breakthrough. The press release referenced within your wiki citation is well worth reading in this context

Yes: Gravimetric measurements from GRACE have been a breakthrough. The press release referenced within your wiki citation is well worth reading in this context: https://www.jpl.nasa.gov/news/news.php?feature=4626 https://www.jpl.nasa.gov/news/news.php?feature=4626 Besides in situ wells, other helpful measurement techniques are InSAR (interferometric SAR) and post-processed GPS. Both let you measure surface subsidence to better than 1cm accuracy over broad areas, mostly due to groundwater withdrawals. This subsidence (which is in the multi-meter range in parts of CA, https://www.usgs.gov/centers/ca-water-ls https://www.usgs.gov/centers/ca-water-ls) is of concern in and of itself, due to disruption of infrastructure like highways and pipelines caused by subsidence. But, subsidence is indirect as a measurement of groundwater withdrawals, because you don't know the relationship between height lost at the surface and volume withdrawn underneath. This depends on a compaction parameter which is very hard to know. Property owners can stymie the use of wells as a groundwater monitoring tool, because it is often not in their direct interest to supply information about local groundwater depletion. For this and other reasons, it's rather hard to use well data, even in well-instrumented areas like California.