In an attempt to compete, in 1839 the canal was extended to 20 kilometres (12 mi) long, with 42 locks to raise or lower boats moving between the sections of level water.

The original plan conceived by Alléon de Valcourt in 1749 was to build a canal that would link the upper Loire to the Rhone.

[4] In 1751, there were 1,200 mules engaged in carrying the coal from Rive-de-Gier to Givors, from where it was taken by water north to Lyon and south to the towns of the Midi.

[3] The watchmaker and engineer François Zacharie proposed to connect the Loire to the Rhone by a navigable canal 56.2 kilometres (34.9 mi) long that would mount the Gier and its tributary the Janon, cross the watershed at Saint-Etienne and descend the Furan to exit on the Loire near Andrézieux.

He filed his proposal early in 1758, and had to wait in Paris until 28 July 1760 for a favorable report from the Conseil du Roi.

[1] Letters patent were issued to François and Guillaume Zacharie on 6 September 1761 giving them the right to build and then use the canal for forty years, after which it would revert to the crown.

[5] The king appointed an engineer to oversee construction, and an inspector of roads and bridges, to be paid by the concessionary.

The concessionary and his heirs, successors and assigns would enjoy the canal for sixty years before transferring it to the king.

[5] The project continued to run into difficulties with malfunctions, financial problems and threats of work stoppages.

[1] New letters patent were issued on 12 August 1779 that doubled the rates and extended the term to ninety-nine years.

[8] The canal had to contend with initial opposition from the carters, who used force to prevent coal being taken from the pits to the loading points.

[10] The combination of the glass works and the canal transformed the sleepy rural village of Givors into an industrial town.

Its nodal position, later reinforced by construction of various railways, explains the development of the glass works and later of iron and steel manufacture.

[13] In December 1788, King Louis XVI approved construction of a reservoir to supply water to the canal in dry periods.

The concession holders had repaid most of the debts they had incurred to build the canal, including many improvements since it was opened, and were able to pay healthy dividends.

An 1824 account described a superb water station at Givors on the right bank of the Rhone, an excellent basin at Rive-de-Gier for loading, fine buildings for administration of the canal and spacious shops and warehouses.

On the return trip, boats carried some of the merchandise of the Midi including iron, oak wood and other things needed by the factories of the Loire department.

There were many factories making window panes, bottles and glasses, and the port had a busy trade in coal shipment.

[15] The canal's high tariffs and excellent profits attracted interest in building a competing railway.

In fact the steep section from Rive-de-Gier to Saint-Etienne was beyond the power of steam traction engines of the day.

On the downhill return journey, the horses were placed in wagons, and the 22 kilometres (14 mi) distance could be covered in an hour.

[21] On 3 December 1831 a royal ordinance allowed the company to extend the canal west to La Grand-Croix.

[10] Until the end of the 19th century the municipality of Givors held that the canal was essential to development of the town, and that barge traffic was still a viable industry, fighting against closure of the canal and demanding that it remain navigable for its entire length despite mounting evidence that it was obsolete.

An 1884 writer described the region of Échalas and Saint-Romain-en-Gier, where the country was furrowed by the river, the canal, the railway and the national road.

[25] The route from Givors-Canal to St. Etienne passed coal mines, large smelting works and iron foundries.