Complex sentence: The bridge has three tiers of arches, standing high, and formerly carried an estimated 200 million liters (44 million gallons) of water a day to the fountains, baths and homes of the citizens of Nîmes.
Split into simpler sentences: The bridge has three tiers of arches, standing high. The aqueduct formerly carried an estimated 200 million liters (44 million gallons) of water a day to the fountains, baths and homes of the citizens of Nîmes.