However, the relatively low classification, based on wind speed, was deceptive because Katrina produced the highest storm surge ever recorded in the United States. Harvey: It made landfall in Rockport, Tex., on Friday as a Category 4 storm, measuring 200 miles across, but was quickly downgraded. The storm inflicted more than $100 billion in damage, with most of it caused by wind, storm surge and the failure of the levees. RainfallKatrina: Rain was not the main problem with Katrina, which yielded 5 to 10 inches of rainfall in a 48-hour period. Harvey: By contrast, Harvey brought a deluge, with up to 50 inches of rain predicted over the next several days — more than Houston receives in a year.

Source: New York Times August 28, 2017 22:10 UTC