Iowa is removing deadly dams, making whitewater parks: Water quality has become a huge issue in Iowa. Studies show that a dam creates an impounded area behind it that increases the retention time of nitrogen, phosphorus and sediments, lowering the water quality of the impounded area. When a dam is removed, it may simply transport the problem downstream, but in some rivers, water quality has improved overall.
Dam removal leaves a wilder river and leads to improvements in habitat and number of species, Hoogeveen said.
And, in the bargain, save lives.