1808 saw the opening of the section between Laroche and Dijon, thereby providing access to the Saône and so, indirectly, to the Rhône valley. At this time the challenge of how the canal should cross the Drainage divide between the Saône and the Yonne valleys was still being argued, but in 1812 the adopted solution involved a tunnel and the creation of reservoirs to feed water into the higher pounds of the canal. The tunnel was built between 1826 and 1832, and in 1832 the entire canal was opened for navigation, although work on the important feeder reservoirs was not completed till 1840.