 This aqueduct acquired water mainly from a lake just north of Rome called Lacus Alsietinus (a small lake in southern Etruria, currently known as Lago di Martignano) and some from Lacus Sabatinus (Lago di Bracciano).The length of this mainly subterranean aqueduct was 22,172 paces (about 32.8 km) and had arches supporting 358 paces (about 1.89 km).Its water supply had a diameter of 392 quinariae (about 9 m).