It began as little more than a modest trench in the ground, but its name—Zanja Madre, or Mother Ditch—speaks to the importance of this proto-aqueduct to early Los Angeles. Diverting water from the free-flowing Los Angeles River, the Zanja Madre did indeed rear tiny Los Angeles, founded in 1781 as an agricultural colony on the outskirts of the Spanish empire. The ditch irrigated the settlers' fields. It quenched the thirst of livestock. It provided a ready source of domestic water. In short, it gave life to Los Angeles.
Part of the Zanja Madre, which supplied the city with water into the 20th century and in later years was lined and encased with brick, was uncovered during construction of Metro's light-rail Gold Line in 2005. A short piece of the brick pipeline is still exposed alongside the tracks near the Los Angeles State Historic Park.
Now, construction of the mixed-use Blossom Plaza development in L.A.'s Chinatown district has likely unearthed another segment of this old waterway. News of the discovery broke in March, but uncertainty surrounded claims that the buried brick was actually the Zanja Madre until earlier today, when the Friends of the Los Angeles River shared these photographs (reproduced with permission above and below) by William Preston Bowling. As the photos reveal, the pipeline unearthed in Chinatown bears a striking resemblance to the section of the Zanja Madre along the Gold Line tracks.
Historical maps also seem to confirm that the Zanja Madre once ran through the site, located along College Street between Broadway (previously "Calle de Eternidad") and Spring (once "Calle Principal"). This 1875 map from the Huntington Library shows the waterway crossing the construction site:
As does this 1868 map from the Los Angeles Public Library's Map Collection: