What did the Summerians use from the Tigris and Euphrates River?

The Sumerians utilized the Tigris and Euphrates Rivers primarily for irrigation, which enabled them to cultivate crops in their arid environment. They developed an extensive system of canals and dikes to manage water flow and control flooding. Additionally, the rivers provided a source of fish and other aquatic resources, as well as serving as vital transportation routes for trade and communication.