Suez Canal construction. Illustration of a waterway being opened during the construction of the Suez Canal, the navigable passage between the Red and Mediterranean Seas. The waterway here, the Sweetwater Canal, was built in 1864 to provide fresh water to the labourers working on the main canal until its completion in 1869. The Suez isthmus, through which the main canal was built, consists of a low desert with salt lakes and marshes filling the lowest depressions; it has virtually no fresh water sources. The Sweetwater Canal was opened by M. Ruyssenaers in the absence of the Suez Canal's main engineer, Frenchman Ferdinand de Lesseps (1805-94).