The source of the small Ahr River is hidden in the cellar of an 18th-century stone building in the town of Blankenheim, in Germany's far west. From there, it quietly flows through its stone bed past the half-timbered houses of this medieval town in the Eifel region.

Nearly six months ago, this river that is barely more than a creek was transformed into a raging torrent that tore apart the lives of tens of thousands of people living along its banks.

It's early in the morning, and the temperature is a chilly -9 Celsius (15.8F). In the inn across the street from the source of the Ahr, no one seems to be awake yet; Christmas lights are twinkling in the windows.

In the bakery around the corner, the first customers are asking for whole-grain rolls. The saleswoman knocks on her counter three times for luck, when I ask how they experienced the disaster. "The flood didn't hit us so bad here, thank goodness," she says. "But if you're driving down the Ahr, what you see will make you weep. The Ahr Valley is a sad sight."

Traces of trauma

The Ahr stretches for about 85 kilometers (53 miles), from the hilly Eifel region to the Rhine River. At first, it drifts gently downhill through wide meadows covered in winter frost. Thirty-five kilometers later, the valley narrows and the small stream turns into a river that loops around the picturesque village of Schuld, with its 700 inhabitants.

On the night of July 15, the Ahr suddenly ceased to be a river as days of rain turned it into a deluge. In Schuld, it swept away entire houses.

Hans-Peter Diel's house remained standing, but the water engulfed the ground floor. He and his family had taken refuge on the upper level. Now, Diel stands in front of his house and points to a brown stripe on the outer wall, showing the level of the waters that made his house inhabitable.

For the past six months, the Diels have been living with relatives, coming back to clean up and rebuild whenever they have found the time. They have carried mud and debris out of the house, knocked the plaster off the walls, torn out the floorboards. They are among an estimated 42,000 people in the Ahr Valley who were affected by the flood.

"We just kept going," says Diel. "Along with many, many helpers by our side. Our biggest wish was to be back home for Christmas. And that wish has come true."

The Diels' Christmas tree, decorated with colorful glass balls, stands in front of the house, for now. Inside, they are still plastering and painting. Furniture is still missing, as are doors and kitchen furniture. "But the main thing is that we're home again," says Diel. For the holiday, his wife Nicole wants to set up a Nativity scene with the figurines they use every year: Joseph, baby Jesus, livestock and shepherds — they all survived the flood unscathed.

From Schuld, I travel on across temporary bridges and past the countless excavators used to rebuild the riverbank. They have heaped up small mounds of earth, tree roots, car tires and plastic pipes.

By the roadside, I see a few frostbitten pansies planted around a granite stela. Someone has placed candles, wooden angels and white stones around the slab. This little memorial was put up to commemorate a family of five who died in the flood — five of a total of 134 people lost their lives that night in the Ahr Valley. The parents had taken refuge on the roof of their house in Ahrbrück with their children — 5, 6 and 16 — as the water rose higher and higher. But the flood swept them away along with their house, leaving behind only the cellar.

Helpers came — and stayed

A few towns further downstream, in Altenahr, most of the houses on the main street are still standing. But the windows and doors of the former hotels and wine bars are barricaded with plywood. At the Hotel Rittersprung, "Hoffnungswerk" (Work of Hope) is written on the doorbell. Erika Neustädter opens the door and invites me in.

We pass through a dark corridor, past rough masonry and makeshift ceiling supports, into the kitchen. The space is furnished with brown leather sofas, fairy lights hanging from the wall and a radiant heater, to provide some warmth. Four candles are burning in an Advent wreath on a long wooden table. Neustädter and her roommate, Martin Petlewski, take a seat.

"I moved to this region to help," says Neustädter, who joined the "Hoffnungswerk" association after the disaster and plans to stay for a year. The 30-year-old is assisting those affected by the flood to fill out numerous forms to get government aid. Federal and state governments have set up a €30 billion ($34.7 billion) fundto help flood victims. 

"Next, I will work in our mobile coffee shop where people can come for a chat over a cup of coffee," she says. "Many people here in the Ahr Valley are traumatized. They need a chance to talk about what they experienced, to be able to come to terms with it."

Behind Altenahr, the valley turns into a gorge, with steep ascents to the right and left. The river winds in tight loops, and wine grows on the rocky slopes above. Will the tourists come back in spring to enjoy this view with a glass of Ahr wine?

On the night of the flood, the picturesque landscape turned into a curse for those living here. In the narrow valley, the water rose to the height of a house. Now, whenever I see an empty space at the side of the road, I think: maybe this is where a house stood and people lived.

In the wine village of Dernau further downstream, Dieter Hess at least has his own roof over his head again, only 50 meters (about 160 feet) away from his destroyed house. The pensioner shows me the mobile home that the Workers' Samaritan Foundation has set up for him.

"Here I have my small kitchen with microwave and induction stove," he tells me. "Over there is the bathroom and here's the bedroom." With its new, white furniture, the tiny living area seems like something straight out of an IKEA catalog. It doesn't take us long to view the 26 square meters (280 square feet) Hess now calls his home.

"So this is where I'll be celebrating Christmas," says Hess. He and other retirees from Dernau moved into their new quarters just five days ago. They share a common room where they can meet for meals or a chat. For six months, Hess lived alone in a hotel room near the city of Bonn, 30 kilometers from here.

Does it even feel like Christmas time to him now? "Not really," says Hess. "My belief in God has waned. After all, an almighty God was also responsible for this flood."

At a time of despair and suffering, many people in the Ahr Valley were grateful to see the many helpers who flocked to the flood area from near and far. Everywhere in the valley, you can still see banners and graffiti on houses thanking those who came to help.

Jasmin Hachenberg drove here from Cologne on the first weekend after the flood to help clear the debris. She took her annual leave so she could stay longer, and then quit her job in film production. "It just felt wrong to just go back to work. Here I can do something really meaningful," she tells me.

Now Hachenberg stands in a former freight shed at the Dernau train station dressed in a hoodie and quilted vest, stacking food donations onto shelves.

"But please, no more cookies and chocolate Santas," she calls out to a donor who walks in. "They're already piling up."

At the small corner shop, Hachenberg and other volunteers provide Dernau residents with canned soups, deodorant and all kinds of everyday essentials. The helpers have received food donations, but also more than half a billion euros in money to help the flood victims.

My journey continues down the Ahr. I pass one last rock, then the valley opens up and makes room for the largest city on the river, with 30,000 inhabitants: Bad Neuenahr-Ahrweiler. White smoke rises from the chimneys on most of the rooftops. But not from all of them: only some of the heating systems here are running again. The streets are packed with vans carrying roofers, tilers, painters and other craftspeople. Their labor is in greater demand than ever before — and appointments are hard to come by.

A narrow escape

In Heppingen, a newer district, Hans Gerd Breuer and his son-in-law show me what was the basement of their house. Here, too, the flood swept away the heating system, and a new one has not yet been installed. Breuer points to a room that's been cleared of mud and debris.

"This is where I kept my model railroad set," he says. "But now it's all gone." On the basement stairs, Breuer pauses briefly. His son-in-law explains that the 82-year-old can't get the sound of the water out of his head. He had just gone down into the cellar to rescue some documents when the water started to rise. It rose so quickly that he nearly drowned.

Breuer had taken out insurance against flood damage — unlike many homeowners here in the valley. But the insurance company is refusing to pay up. "They're trying to drag everything out. Eight assessors have already been to my house to look at the damage. It's grueling," says Breuer. Until his insurance company pays him, Breuer will have to pay the workers who are rebuilding his house out of his own pocket. "Christmas back in my home, that's just not going to happen," he says. He hopes to be able to move back in by Easter.

Just before the Ahr reaches the Rhine, it passes gravel and sandbanks in a nature reserve. Here, too, the river raged. The wooden beams of a footbridge lie wildly scattered on the riverbank, resembling conceptual art.

It's quiet here, the silence only broken now and again by the call of a bird. "There are rare species here like bank sandpipers, common mergansers, grey wagtails," says Karin Feret, an 80-year-old who is out and about with binoculars and a camera. "Today I've also seen some kingfishers."

"I've spent my whole life here; I'm emotionally attached to the Ahr," she says. "It's always been beautiful here. But the way the Ahr raged this year, that is a whole different story." Feret hopes that all the rare species will soon return to the area. And that normality will soon return for the people of the Ahr Valley as well.

Edited by: Rina Goldenberg