Summer flooding in the Delaware River Basin is expected to increase in both size and frequency as the climate continues warming, intensifying future floods along the Delaware River’s mainstem, a study found. Floodwaters in the northern Delaware River Basin could create a sort of snowball effect of flooding — minus the snow — when they meet with other flooding tributaries and grow in intensity downstream. “When you warm things up, you get a big increase in the number of floods for the entire river basin to sort of synchronize in time,” he said. Flooding historyFlooding events have rocked the Delaware River Basin in the past, creating change in more ways than one. In May, flooding conditions closed the Delaware River Water Gap, a somewhat rare occurrence.