The Path to Your Tap Isn’ta Straight Line From the Sierra Mountains and the Colorado River tothe ground beneath our feet here in Los Angeles, thewater that fuels our city comes from diverse sources. LADWP takes wastewater from Los Angeles homes and businesses and purifies it for reuse in irrigation and groundwater replenishment. Underneath the city are natural aquifers that LADWP protects and replenishes, storing water for future use. When it rains where does all the water go? This water can be captured into the groundwater, pumped and used as another source of water for the region. While LADWP increases investments in more reliable, local supplies, we’re augmenting our supply with purchased, imported water from the Colorado River and State Water Project. While LADWP increases investments in more reliable, local supplies, we’re augmenting our supply with purchased, imported water from the Colorado River and State Water Project. Built in 1913, the LA Aqueduct was at the time the largest water infrastructure project in the world. Now more than a century later, the aqueduct still runs 233 miles north of Los Angeles carrying fresh runoff from the Eastern Sierra to the L.A. Basin.