High water levels are wreaking havoc in the Great Lakes. The five inland seas are bursting at the seams during the region's wettest period in more than a century, which scientists say is likely connected to the warming climate. And no relief is in sight. Forecasters expect the lakes to remain high well into 2020. Homes and businesses are flooding, roads and sidewalks are crumbling and beaches are washing away. Homeowners and agencies are extending battered seawalls, constructing berms and piling stones and sandbags. Some are elevating houses or moving them farther inland. Less than a decade ago, the Great Lakes had the opposite problem: levels were at record lows. Experts say these abrupt swings may continue as global warming brings more extreme storms and droughts.