By the time Hurricane Harvey ended, 27 trillion gallons of rain poured down on Texas and Louisiana. The storm lasted for over a week, but it’s impossible to know how long it will take for the flood to recede throughout the region. <br /> <br />-- <br /> <br />FOLLOW POPULAR SCIENCE <br /> <br />http://www.popsci.com <br /> <br />Facebook: https://www.facebook.com/popsci <br /> <br />Twitter: https://www.twitter.com/popsci <br /> <br />Instagram: https://www.instagram.com/popsci <br /> <br />Snapchat: https://www.snapchat.com/add/popularscience <br /> <br />Pinterest: https://www.pinterest.com/popularscience
