So far, Harvey has unloaded more than 9 trillion gallons of water. Since Thursday, 44 Texas counties have reported rainfall of at least 20 inches. That represents half a normal year’s worth of rain in under a week, with more precipitation expected in the days to come. Much of that rainfall is not centered on the coast, but further inland. Dayton, for example, which is roughly 40 miles from the coast, has received over 39 inches. So much rain has fallen that the National Weather Service (NWS) has had to update the color charts on their graphics in order to effectively map it.