Islamic scientists and engineers continued improvements on the systems of water hydrology and irrigation techniques dating back to Ancient Mesopotamia and later developed under the Roman Empire. We find extensive water projects, including the use of the Noria or water wheel found in Syria and Iraq, the use of the saqiyya or smaller water wheel used to lift water from rivers or pools into fields, and qanats or channels dug underground to divert water tables from hills and mountains down into towns.
The Qanat System was an ancient technology used to detect and divert underground water tables from hills down into towns and agricultural fields. The diagrams below shows one of these as used in Ancient Arabia.
The map below from Water Engineering in Ancient Civilizations shows the extensive use of qanat water channels and canals throughout Muslim North Africa and Andalusian Spain.
Al-Jazari, 1136-1206 was the most famous mechanical engineer of the Abbasid period in Iraq. His many inventions included the device shown below to lift water from moving river water up to higher levels for irrigation or for supplying water to towns.