The water supply that maintained Rome was an important part of city life. Eleven aqueducts supplied the city of which the Aqua Marcia was the longest. Purportedly paid for out of the spoils of the Punic wars, including the defeat of Carthage, plus also the conquest of Corinth and was constructed, or perhaps restored, between 144 and 140 BC by the Praetor Quintus Marcius Rex.
The ancient source for the aqueduct was near the modern towns of Arsoli and Agosta, over 91 km away in the Anio valley.
Given that water supply was so critical to the survival of the city it is not surprising that the Aqua Marcia and other aqueducts are feature on the Roman coins. Two such coins are featured in my own collection.
An interesting coin that shows, on one side, a portrait of the fourth king of Rome, Ancus Marcius, with an equestrian statue, perhaps of Q. Marcius Rex. There are some problems with associating the stature with Marcius Rex as there is no record of his statues in Rome ever being equestrian. But a statue of him was erected in Rome on the Capitol, where the aqueduct eventually arrived in the city, so this reverse probably does represent that monument.