The Spadra Basin is a groundwater basin located in the San Gabriel Valley, in the western portion of the City of Pomona. The basin lies near what used to be the bustling town of Spadra, located on an important historic stagecoach travel route. Today, the Spadra Cemetery and the Phillips Mansion, owned by the Historical Society of Pomona, are all that remain of the town.   This small aquifer supplies groundwater primarily to the City of Pomona, Walnut Valley Water District, and Cal Poly Pomona.  Water from the basin is used by local residents and for industrial and irrigation purposes.