The clean-up associated with this weekend’s Lake Delhi dam break is going to be enormous. Tom McCarthy, an environmental specialist at the Iowa DNR, says a number of chemicals washed into the river when the northeast Iowa dam burst.

“(We) saw a lot petroleum products coming down, a lot of sheen,” McCarthy says. “Propane tanks were venting. We’ve had tremendous washing of the farm fields.  We’ve lost a lot of the fertilizer.”

McCarthy was at the dam Saturday when it began to collapse.  “It was sweeping trees below that berm cut, sweeping those trees away,” he says. “Boats were going through. It was just like someone pulled the plug on a bath tub. It really started to go.”

McCarthy says between 250 and 300 homes were damaged in the Lake Delhi area when the dam failed.

City officials and volunteers in Maquoketa stacked sandbags on the city’s north side on Sunday. The Maquoketa River is expected to crest there later today at 11 feet above flood stage. The focus is protecting Maquoketa’s wastewater facility, electric plant and water treatment facility. Lyn Medinger, Jackson County’s emergency management coordinator, says more sandbags were added over the weekend as the crest forecast changed when the Lake Delhi Dam failed.

“Right now, we’re just fighting the clock,” Medinger says. “We’ve got a couple of low-lying areas that we need to sandbag.”

The crest is expected around 35 feet, well over flood stage of 24 feet. Medinger says the predicted crest for the river changed when the Lake Delhi Dam failed on Saturday. “When we got our initial forecast of 34.8 (feet), we were good,” he says. “We (ran) a model when the dam broke up at Lake Delhi, now it’s giving us (an additional) two to three feet. They (re-ran) the model — we’re going to be sitting at 35. Right now our levee that protects that is right at 35.”

Medinger says a number of homes in Jackson County have been flooded along the river and some residents have been evacuated, but the most extensive damage in the county has been to surrounding crops. The river is expected to crest in Maquoketa at 1 p.m. today.