For middle school and up people?

they were the first to invent irrigation, their society developed at the base of the delta and formed by the tigris and euphrates river. when the rivers flooded the silt from the bottom of the rivers covered the land mixing with soil and making it fertile. then the flooding was a threat to the sumerian homes because it could have flood them. after it flooded and the water had evaporated the ground was left caked with salt. this forced the sumeranians to find other ways of irrigation so they started to build the cs to direct the water in different directions. this also allowed them to distribute the water in more precise amounts.