Una Lake is a sag pond in Palmdale, Los Angeles County, California.

It is in Antelope Valley, in the San Andreas Rift Zone at an elevation of 2,815 feet/858 meters.

Subsequently, in 1897, the South Antelope Valley Irrigation Company built a dam west of the railroad causeway and built a ditch from Little Rock Creek to keep Una Lake full year round for irrigation purposes south of Palmdale.

[2] : 711  The size of this reservoir of Una Lake and these works can be seen on the 1915 U. S. Geological Survey, California, Lake Elizabeth Quadrangle, Topographic Map.

[3] Subsequently, the dam was improved and the larger Harold Reservoir, later Lake Palmdale, was created in 1924.