More dams are being removed from rivers as they get older and no longer produce hydropower. Researchers have found after these dams come down, rivers return to their natural state surprisingly fast.
Over the years lots of sediment backs up behind dams. Ecologists have worried the release of that sediment would harm habitat and cause flooding.
But a study from Oregon State University found that didn’t happen. Researchers studied two rivers in Oregon before and after dams were removed.