Hayfield Pumping Plant, renamed in 1967 to The Hinds Pumping Plant in honor of Julian Hinds:
"Metropolitan Water District of Southern California's general manager and chief engineer from 1941-1951, but began work on the Colorado River Aqueduct in 1929 soon after the district was organized." (watereducation.org/aquapedia/julian-b-hinds)
This is part of the Colorado River Aqueduct that you can easily see from I-10. At the Hayfield exit, the Hayfield road goes north to the Pumping Plant.
This is the last pump on the aqueduct and raises the water up above 1,700 feet so it can flow easily the rest of the way into the L.A. area.