The Ornain is a French Rivière the North-East of the France. Affluent of the Saulx, Ornain takes its source in the south of Gondrecourt-the-Castle and is thrown in the Saulx out of Right Bank, with Etrepy.

Cours

Ornain is born from the junction of two rivers which are Ognon and the Maldite in the south of Gondrecourt-the-Castle.

Its course leaves the department of the Meuse to Rancourt-on-Ornain to arrive in that of the Marne at Alliancelles for finally throwing itself in the Saulx with Etrepy (out of Right Bank).

According to initially a direction south-north, its course inflects for finally being thrown in the Saulx in a East-West direction.

It is, with Saulx, one of the two principal rivers which bathe the south of the plate Barrois in Meuse.

Departments and main cities crossed

• Meuse (55):

• the Marne (51)

Affluents

• the Barboure with Naix-with-Forging mills

• the Noitel with height of the Mill of Givrauval
• the Salmagne with Guerpont
• the Naveton with Bar-le-Duc

Hydrology

By the Saulx then by the the Marne, Ornain belongs to the watershed of the the Seine.

Ornain is a well fed river, like the majority of the river of the area catchment of Saulx resulting the heights of the Barrois. Its flow was observed over one 39 years period (1968-2006), with Varney, locality of the department of the Meuse located at five kilometers downstream from Bar-le-Duc, i.e. little before its confluence with the Saulx. The catchment area of the river is there of 840 km ², that is to say almost the totality of this last.

The interannual medium flow or module of the river with Varney is of 10,9 m ³ a second.

Ornain present of the seasonal fluctuations of flow marked enough, with high waters of winter-spring characterized by an average monthly flow located between 17 and 23 m ³ a second, from December to March included (with an in January maximum and February), and low waters of summer, July to September included, with a fall of the monthly medium flow up to 2,22 m ³ in August.

With the low water level, the VCN3 can fall until 0,380 m ³, in the event of dry quinquennial period, that is to say 380 liters a second, which is somewhat severe, but can be compared with the VCN3 of the close rivers (Vière, Bruxenelle, Saulx) and is definitely higher than that of the Chée. The VCN3 is the past minimal quantity or minimal flow over three days consecutive.

As for the risings, they can be rather important, characteristic shared by the majority of the rivers of the east of France, but without common measurement with the risings of the affluents of the the Moselle and the Meuse located more at the east (Orne, Madon, Mouzon for example).

Thus the QIX 2 and QIX 5 or calculated flows of biennial and quinquennial rising are worth respectively 77 and 110 m ³ a second. The QIX 10 or calculated flow of decennial rising is of 130 m ³ a second, the QIX 20 of 150 m ³, while the QIX 50 is assembled to 170 m ³ a second (see note).

The recorded maximum instantaneous flow with Varney during the period of observation, was of 151 m ³ a second on December 21st, 1993, while the value maximum day laborer was of 147 m ³ a second on December 22nd of the same year. By comparing the first of these values on a QIX scale of the river, one notes that this rising was only of a vicennial nature, and thus intended to rather frequently reproduce.

Ornain is an abundant river, well supplied with precipitations of the Barrois. The Lame of water past in its catchment area is of 412 millimetres annually, which is definitely higher than the overall average of France all confused basins, and also to the average of the basins of the Marne (274 millimetres in Paris), and of the the Seine (240 millimetres). The specific Débit of the river (or Qsp) posts of this fact the rather high figure of 13,0 liters a second and per square kilometer of basin.

Fish

Ornain is a river classified in first category.

The valley of Ornain

The valley of Ornain which is located almost exclusively in the department of the Meuse concentrates in its average part the main cities of the south of this department: Ligny-in-Barrois, the prefecture Bar-le-Duc and Revigny-on-Ornain.

This valley is also an important axis of communication since the railroad Paris - Strasbourg borrows it Revigny-on-Ornain from Nançois-on-Ornain. The Canal of the Marne in the Rhine also passes by this valley until Saint-Joire from where it leaves by the tunnel Mauvages.

This valley gathers also the major part of industries of the sector. One will quote for example:

• automobile manufacture (Evobus) and optics (Essilor) with Ligny-in-Barrois
• wire-drawing mill, precision mechanics
• industry of wood (plating) (Ober) with Longeville-in-Barrois
• textile industry (Shepherdess of France) with Bar-le-Duc

Historically, the men were established since the time Celte on the edges of this valley. One thus finds the traces of two oppida on the heights overhanging the river:

• one with Fains
• and the other with Boviolles. This last human settlement then moved in the valley of the time of the Roman Paix to give the town of Nasium (between Naix-with-Forging mills and Saint-Amand-on-Ornain).

Ligny-in-Barrois was capital county of Ligny and Bar-le-Duc capital of the Duché of Bar.