I wuld say it should be the work of several hundred years on-and-off to complete an engineering task like a Zaqiri Canal. Consider that the construction of the Pyramids usually took the whole life of the Pharoah for whom they were intended, and marshalled a tremendous amount of resources. Cathedrals in Europe were usually constructed on a less-intense schedule, but the largest could still take 100-200 years to see completion and required huge amounts of labour, wealth and time nonetheless. 

Just fyi, I'm going to add in a couple of Human tribes and nations to the world in my next update; I'll try to flesh them out, and you can use them as you like. I'll throw a few bones the way of the Grogar - ancient Empires and all that. The map seems pretty empty, so I'm going to take the liberty of populating it with a few [s]doomed[/s] proud human/promethean/bastard [s]sacrifices[/s] kingdoms.