Volunteer rescuer Matt Clarke searches for local residents following a mandatory evacuation order in the area beneath the Barker Reservoir as water is released after Hurricane Harvey caused widespread flooding in Houston, Texas on August 31, 2017. In Houston, America's fourth-largest city, some of the 2.3 million residents got relief as the raging waters receded. But in several other towns in the Lone Star State doused by days of torrential rains since Harvey smashed into the US Gulf Coast almost a week ago as a Category Four hurricane, the situation was dire. / AFP PHOTO / MARK RALSTON