They built a channel to contain the river, and they drained the marshes (grassy wetlands) surrounding it. Now the city could be built right up to its banks. That’s why today, the Seine River is a huge part of Paris’ urban environment.
As I mentioned, settlers thrived around the bountiful Seine River and the fertile lands around it. There was a lot for people to eat from hunting in the woods and growing crops in the fields. Unfortunately, today the Seine is a bit polluted, so people don’t eat the fish that are in the river. Also, because Paris has been built up, there are no longer places to grow crops in the city.
Today, people don't directly depend on the Seine for their survival. Now they love it for other reasons: strolling along its concrete banks, taking boat cruises and simply enjoying its beauty. People love to live close to the Seine in Paris because it is a relatively peaceful part of an otherwise bustling city.
Lately, Paris is dealing with more serious flooding of the Seine. Because they get a lot of rain in the fall and winter, the Seine River always swells with water each year. In the past, when Paris was a more natural area, the swelling river was a normal and positive event. The flooded river would help make the lands more fertile by bringing nutrients to the soil. Also, there were more marshes around; these spongy wetlands could absorb some of the flood water. But today, the Seine is contained in a steep channel, and when it floods over the channel banks, it causes a lot of damage to the roads and buildings.
