View looking north up the main street of western Pisidian Antioch from the gate area. Just over the large block in the foreground, the water channel that ran down the center of the street—toward the viewer—is visible. Note the baffles in the interior. Water would have rippled over these creating a pleasant visual, auditory, and sensual effect.
On both sides of the channel were the actual roadways and then on the edges of them, there were porticoes and shops!
A much better-preserved system is visible at Perge!
For a modern example of such a watercourse (in Izmir) Click Here.
It is interesting that in the book of Revelation (22:1–2) the "New Jerusalem" is described as having ". . . a river of the water of life, clear as crystal, coming from the throne of God and of the Lamb, in the middle of its street." At Perge, the water, instead of coming from the throne of God, comes from under a representation of "Cestrus" at the nymphaeum.