Short answers, pulled from the story.
The Roman Senate authorized the construction of the Aqua Marcia in 144 BC. The project concluded when the Senate rejected traditionalist objections to bringing water to the Capitoline Hill on the 2nd of May 140 BC.
Praetor Quintus Marcius Rex oversaw the construction of the Aqua Marcia using funds from spoils taken during the destruction of Corinth in 146 BC. He was an ancestor of Julius Caesar and received judicial authority specifically to complete this massive infrastructure project.
The ancient source sat near small lakes formed by two springs in the Anio valley between the modern towns of Arsoli and Marano Equo. This location east of Rome also supplied other aqueducts including Aqua Claudia and Aqua Anio Novus.
Ponte Lupo stands more than 30 meters high and stretches over 80 meters long across the deep Aniene Valley. It sits on a private estate of San Giovanni in Campo Orazio today after being built in 144 BC.
Frontinus measured the Aqua Marcia flow at its source around AD 97 recording 4690 quinariae total volume. Modern estimates for one quinaria vary widely ranging from specific cubic measurements to different daily volumes creating calculated flows between approximately 150,000 and 200,000 cubic meters per day.