Hello! I live in the Middle East. On the Fertile Crescent. The Tigris and Euphrates rivers are our most important rivers!
The Zagros Foothills didn't have enough space because more and more people moved there. So then food shortages started to happen so I moved to the Sumer plains.
In the spring, the snow melted off the mountains into the rivers so the rivers would flood. We sun cooked soil until they got as hard as a rock and put them on the sides of the rivers to prevent them from flooding. Another thing we did is we built levees on the sides of the rivers.
Our canals would get clogged with silt really easily so we would have many people help from other places move the water from one reservoir into another to make sure the water level is equal. Since other people helped from other places more and more people started to come to our area.
Once the city got even bigger people started fighting about who get to use more water and some cities even blocked other cities canals so they cant use their water
These advancements help Sumer become more powerful is that there's a lot more people to to protect Sumer and maybe others cities too.