Site Location

• The first step in building an aqueduct in the ancient Roman Empire was to locate a suitable water source. Water sources included perennial springs, or rivers that consistently produced a high volume of water year round. Surveyors with military backgrounds looked for areas with natural slopes of at least 1 percent and which would move water while requiring the construction of bridges and tunnels as infrequently as possible. Land would be purchased from owners, where necessary and tools like gromas, used to measure right angles, chorobates, used to level surfaces and dioptras, used to measure vertical angles, were employed to take survey measurements of the land.
  
  

Channel Construction

• Since gravity moved water through most all Roman aqueducts along a continually downward slope, channels and sometimes pipes were the main elements in aqueduct construction. Channels were dug following the natural terrain of the land to ensure a continually downward slope. Tunnels were dug, when necessary, to go through a mountain if going around it would not maintain the downward slope of the land. A hole was dug, a channel constructed and then finally, covered. When necessary, a bridge was constructed with arches to move water over valleys.
  
  

Covering Channels

• Channels were covered with three materials, masonry, lead pipes and terra cotta pipes. The most common channel material was masonry. Pointed roofs and conduits were constructed out of concrete and crushed stone to cover the channels. Channels themselves were lined with waterproof plaster called opus signinum.
  
  

Operation

• Once constructed, Roman aqueducts had to be constantly maintained. Leaks were continually fixed and debris was often removed. Maintenance paths and roads along with manholes were built alongside aqueducts and into subterranean tunnels after they were completed and organized teams of professionally employed laborers continually kept them in good working order.