The Thérain is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, tributary of the Oise River

Oise River

The River Oise is a right tributary of the River Seine, flowing for 302 km in Belgium and France. Its source is in the Belgian province Hainaut, south of the town Chimay. It crosses the border with France after about 20 km. It flows into the Seine in Conflans-Sainte-Honorine, near Paris...

. It rises between Saint-Michel-d'Halescourt

Saint-Michel-d'Halescourt

Saint-Michel-d’Halescourt is a commune in the Seine-Maritime department in the Haute-Normandie region in northern France.-Geography:A small farming village situated by the banks of the river Epte in the Pays de Bray, at the junction of the D61 and the D130 roads, some northeast of...

 and Grumesnil

Grumesnil

Grumesnil is a commune in the Seine-Maritime department in the Haute-Normandie region in northern France.-Geography:Grumesnil is a farming village situated in the Pays de Bray, some southeast of Dieppe at the junction of the D105 and the D8 roads...

 in Seine-Maritime

Seine-Maritime

Seine-Maritime is a French department in the Haute-Normandie region in 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...

 at 175 meters elevation. It flows generally southeast, through Songeons

Songeons

Songeons is a small village in northern France. It is designated municipally as a commune within the département of Oise....

, Milly-sur-Thérain

Milly-sur-Thérain

Milly-sur-Thérain is a village in northern France. It is designated municipally as a commune within the département of Oise.-References:*...

, Beauvais

Beauvais

Beauvais is a city approximately by highway north of central Paris, in the northern French region of Picardie. It currently has a population of over 60,000 inhabitants.- History :...

, Hermes

Hermes, Oise

Hermes is a small town in northern France. It is designated municipally as a commune within the département of Oise....

 and Mouy

Mouy

Mouy is a town in northern France. It is designated municipally as a commune within the département of Oise....

, and joins the Oise at Creil

Creil

Creil is a large town in northern France. It is designated municipally as a commune within the département of Oise.-History:Archaeological remains in the area include a Neolithic site, as well as a late Iron Age necropolis, perhaps belonging to a Gaulish fortress or protected camp.The city itself...

.

Its valley, near the metropolitan area of Paris

Paris

Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

, has been a highly industrialized and populated area, and Beauvais

Beauvais

Beauvais is a city approximately by highway north of central Paris, in the northern French region of Picardie. It currently has a population of over 60,000 inhabitants.- History :...

 lies at the foot of wooded hills on the left bank of the Thérain at its confluence with the 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