Officials in northeastern Iowa are cleaning up in the aftermath of a July 24 dam failure, and early analysis indicates an earthen berm next to a section with concrete spillways was overtopped and eroded away when the rain-swollen, 9-mile-long Lake Delhi overwhelmed it.
“It appears at this point that there was just a lot more water than the dam was designed for,” says Lori McDaniel, supervisor of floodplain management and dam safety programs for the Iowa Dept. of Natural Resources. Further, she says the concrete spillway next to the berm appears to be structurally sound.