This is Mesopotamia it is in the south region the two rivers are Tigris and Euphrates river.
They moved to Zagros but it was getting overpopulated thats when they moved to sumer.
When they moved there was a problem the rivers were overflowing that's when they made irrigation systems and also levees to help control it. they poked holes in the levees for more water also canals for the flow and dams to force in place
Some times the canals need to be clean from rocks so they scooped the water from the reservoir so when they worked together they made more larger comunites.
When they grew they fought the right for water so they built more canals for control and some times block other peoples canals
So in conclusion while there was problems but they had solutions to many things this what made human advancement