Final answer:
The Ancient Sumerians built levees and canals to manage excess water, while modern communities practice water conservation, use technology, and sometimes rely on international aid to address water scarcity.
Step-by-step explanation:
To describe how two separate groups dealt with water issues: one group that had too much water and one that had too little water, we can look at historical examples. Ancient Sumerians faced the problem of having too much water due to unpredictable flooding from the Tigris and Euphrates rivers. They collaborated to construct levees and canals, an effort which eventually led to the development of larger settlements and systems of governance to manage these water control projects.
On the other hand, modern communities, particularly in water-scarce regions, contend with having too little water. These groups implement water conservation measures, such as recycling wastewater, using drip irrigation in agriculture, and imposing water usage restrictions during times of drought. Some wealthy nations combat water scarcity with technology and infrastructure, like desalination plants, while poorer nations often rely on aid and simpler, less expensive conservation techniques.