Simple...
The Roman Empire was very,very powerful..and were ingenious when it came to inventing. The aqueduct was an example of this. The aqueduct could now bring water to people who once didn't have access to it. It'd be connected to a lake/reservoir etc, and would pump water to the city and its inhabitants. The aqueduct filled bathhouses, private pools, etc. Water is necessary in life; the Romans realized this..and created the aqueduct.
Thus, your answer.
