The Thérain () is a

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

, tributary of the

Oise Oise ( ; ; ) is a department in the north of France. It is named after the river Oise. Inhabitants of the department are called ''Oisiens'' () or ''Isariens'', after the Latin name for the river, Isara. It had a population of 829,419 in 2019.< ...

. It is long. It rises between Saint-Michel-d'Halescourt and Grumesnil in

Seine-Maritime Seine-Maritime () is a department of France in the Normandy region of northern France. It is situated on the northern coast of France, at the mouth of the Seine, and includes the cities of Rouen and Le Havre. Until 1955 it was named Seine-Inf� ...

at 175 meters elevation. It flows generally southeast, through Songeons, Milly-sur-Thérain,

Beauvais Beauvais ( , ; ) is a town and Communes of France, commune in northern France, and prefecture of the Oise Departments of France, département, in the Hauts-de-France Regions of France, region, north of Paris. The Communes of France, commune o ...

Hermes Hermes (; ) is an Olympian deity in ancient Greek religion and mythology considered the herald of the gods. He is also widely considered the protector of human heralds, travelers, thieves, merchants, and orators. He is able to move quic ...

and Mouy, and joins the Oise at

Creil Creil () is a Communes of France, commune in the Oise Departments of France, department, northern France. The Creil station is an important railway junction. History Archaeological remains in the area include a Neolithic site as well as a late ...

. Its valley, near the metropolitan area of

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

, has been a highly industrialized and populated area, and

lies at the foot of wooded hills on the left bank of the Thérain at its confluence with L' Avelon.

Affluents

* Ruisseau d'Hardouins * Le Tahier * Ruisseau de Wambez * Le Petit Thérain * L' Avelon * Rivière de Saint-Quentin * Rivière de Saint-Just * La Liovette * Le Wage * Ru de Berneuil * Fosse d'Orgueil * La Laversines * La Trye * Le Sillet * Ru de la Maladrerie * Ru de Lombardie * Le Moineau * Fossé l' Evêque * Le Ruisseau de Saint-Claude * Le Ruisseau de Cires * Le Ruisseau de Flandre

References

Rivers of France Rivers of Oise Rivers of Normandy Rivers of Hauts-de-France Rivers of Seine-Maritime {{France-river-stub