The Roman Empire has garnered itself a mostly positive reputation for the complicated sewer systems that ran underneath many of its cities. While they may have been engineering marvels and precedent setting, there were still major flaws in Roman sewer systems. Roman engineering brought water to the city from the Alban Hills thanks to the aqueduct system implemented in 312 BC Although primitive forms of sewage systems have existed in Rome since pre-imperial times, these were mostly primitive drains that led to the nearby rivers and streams. As the skills of engineers continued to grow, the complexity of the sewers did as well. For example, the Cloaca Maxima was one the first complex and expansive sewer systems that ran under Rome.