reporter: a trauma for nils gÖrres. more than 130 people died in the ahr valley disaster.uses were destroyed and are still uninhabitable. like so many other houses, this one was flooded almost to the roof. living here is out of the questi. nonetheless, gerd gasper and his wife elfriede come here every day to keep an eye on things. gerd: every time you come in here and see the state of it, it's just awful. reporter: an electric fan heater has been drying the brickwork for months. but it's not yet clear if they will ever be able to move in here again. elfriede: if it were spring now, everything would probably be better, including your state of mind. in the evening at 5:00, it's often already dark, and that's when depression sets in. reporter: in the small village of altenburg alone, more than 50 houses have been demolished because they were contaminated or in danger of collapsing. the floods caused around 30 billion euros of damage in all. nils is on his way to his next customer. the gas connection for a temporary shelter needs to be installed. because there's a housing shor