Lubbock is a city in and the county seat of Lubbock County, Texas, United States. The city is located in the northwestern part of the state, a region known historically and geographically as the Llano Estacado and ecologically is part of the southern end of the High Plains. According to a 2015 Census estimate, Lubbock had a population of 252,506. making it the 83rd-most populous city in the United States of America and the 11th-most populous city in the state of Texas. The city is the economic center of the Lubbock metropolitan area, which has a projected 2020 population of 327,424.Lubbock's nickname, "Hub City", derives from it being the economic, educational, and health care hub of the multicounty region, north of the Permian Basin and south of the Texas Panhandle, commonly called the South Plains. The area is the largest contiguous cotton-growing region in the world and is heavily dependent on water drawn from the Ogallala Aquifer for irrigation.