Explanation:

In Punjab, the land between two rivers is known as doab and accordingly the region between Ravi and Beas is known as Bari Doab. Upper Bari Doab Canal, which originates at Madhopur near Pathankot, derives its name from it. It was the first canal to be dug up in Punjab for irrigational purpose; however, at that time it was simply known as Bari Doab Canal system. The prefix ‘Upper’ was added only when a second canal known as Lower Bari Doab Canal was dug.
This 130 mile long canal was dug by Emperor Shah Jahan to bring water to his garden in Lahore from the River Ravi. Centuries later, the same was extended by Maharaja Ranjit Singhji to bring water to fill up the sacred tank in the Golden Temple Complex.
Years later, another canal was taken off from Ravi in the Daob Bari region only. The new canal was known as Lower Bari Doab Canal while the original one began to be referred as Upper Bari Doab Canal.