DES MOINES, Iowa (AP) — For the better part of a century, submerged dams were workhorses of the American heartland, harnessing the power of rivers to run grain mills, generate electricity and keep lakes and ponds full of water as a hedge against drought. "The builders of these dams have created a very elegant trap for human beings," said Nate Hoogeveen, who heads river programs for the Iowa Department of Natural Resources. [...] a spike in deaths is inciting a debate about whether the dams should be ripped out, even if it means letting scenic riverbanks turn to mud. Since the 1950s, at least 441 people have died at 235 low-head dams in 38 states, according to researchers at Brigham Young University. Community leaders also face the concerns of residents who fear that, without a dam, their riverfront homes will overlook nothing more than a muddy creek. [...] Des Moines officials are still wary of the expense and of possibly hurting recreation by lowering the river level.