CNN  — 

About 3 million people were under flood and flash flood watches on Saturday across parts of the Mississippi and Tennessee river valleys as the remnants of Hurricane Delta continued to drench the Southeast.

Delta, now weakened to a post-tropical cyclone, dropped more than 1 foot of rain in Louisiana and its powerful winds pounded communities already ravaged by Hurricane Laura weeks ago. In its wake, it left more than 615,000 homes and businesses along the Gulf Coast without power as of Saturday afternoon, according to