San Lazaro Aqueduct

AqueductLusitania · Merida, SpainBuilt 90 CE

About

A second, less famous aqueduct into Emerita Augusta, drawing from a catchment northeast of the city (Casa Herrera, Valhondo, Las Tomas) rather than from Proserpina, and supplying among other things the baths near the civic forum. Built toward the end of the 1st century CE, crossing the Albarregas gorge on a raised arcade — only three massive buttressed pillars of the Roman structure survive today, since a 16th-century rebuild mostly replaced it along the same line. Some sources tie its ultimate source to the Cornalvo reservoir, though period evidence more directly names the local catchment.

What happened here

Water arrives day and night and never stops. The channel runs mostly underground, following a shallow gradient measured out with a levelling instrument over tens of miles, and it goes up on arches only where the ground drops away. Inspection shafts sit at intervals; gangs work the line constantly, cutting out the lime crust that thickens on the walls and narrows the flow. At the town end the water is divided in a distribution tank — public fountains first by law, then baths, then private houses whose owners have paid for a pipe of a fixed and stamped size. Illegal tappings are a permanent scandal. What arrives is not stored but runs continuously, and the overflow flushes the drains.