(a) The Northern High Plains Eradication Zone consists of Armstrong, Bailey, Briscoe, Castro, Deaf Smith, Floyd, Hale, Lamb, Parmer, Randall, and Swisher counties, and other areas as proposed by the commissioner by rule for inclusion in the zone and approved by referendum in the area to be added.
(b) The Rolling Plains Central Eradication Zone consists of Baylor, Callahan, Comanche, Eastland, Erath, Fisher, Haskell, Jones, Knox, Mitchell, Nolan, Palo Pinto, Scurry, Shackelford, Stephens, Stonewall, Throckmorton, and Young counties; all land in Archer County south of a line following Farm-to-Market Road 422 commencing at the Baylor County line running east to the intersection of Farm-to-Market Road 210, continuing east to the intersection of State Highway 25, and continuing east to the Clay County line; all land in Borden County east of a line seven miles west of the Scurry County line running south from the Garza County line to the Howard County line; and all land in Taylor County east of U.S. Highway 83 from a point commencing at the intersection of U.S. Highway 83 and the south Taylor County line, north to the town of Bradshaw; thence north of Farm-to-Market Road 1086, as the farm-to-market road proceeds west and north to the intersection of the Farm-to-Market Road 1086 and U.S. Highway 277, being all land lying north of the farm-to-market road and west of U.S. Highway 277 from the intersection of Farm-to-Market Road 1086 and U.S. Highway 277 to the point where U.S. Highway 277 intersects the south boundary line of Taylor County; all land in Brown County east of a line following State Highway 279 to Brownwood and continuing along U.S. Highway 377 south to the McCulloch County line; and other areas as proposed by the commissioner by rule for inclusion in the zone and approved by referendum in the area to be added.

(c) The St. Lawrence Eradication Zone consists of that area of Midland County south of a line 15 miles south of Interstate 20 running from the Ector County line east to the Glasscock County line; Glasscock, Reagan, and Upton counties; and other areas as proposed by the commissioner by rule for inclusion in the zone and approved by referendum in the area to be added.
(d) The South Texas Winter Garden Eradication Zone consists of Aransas, Atascosa, Austin, Bee, Bexar, Brazoria, Calhoun, Colorado, DeWitt, Dimmit, Duval, Fort Bend, Frio, Goliad, Jackson, Jim Wells, Karnes, Kinney, Kleberg, La Salle, Lavaca, Live Oak, Matagorda, McMullen, Medina, Nueces, Refugio, San Patricio, Uvalde, Victoria, Wharton, Wilson, and Zavala counties, and other areas as proposed by the commissioner by rule for inclusion in the zone and approved by referendum in the area to be added. Austin, Brazoria, Colorado, Fort Bend, Jackson, Matagorda, and Wharton counties are included in the South Texas Winter Garden Eradication Zone only for purposes of the repayment of debt existing on April 30, 1997, and those counties may not be included in the zone for any other purpose unless the commissioner by rule proposes that an area be included in the zone and the proposal is approved by referendum in the area to be added. The commissioner may apportion any debt existing on April 30, 1997, and designate the appropriate assessment.
(e) The Southern High Plains-Caprock Eradication Zone consists of Andrews, Cochran, Crosby, Dawson, Dickens, Ector, Gaines, Garza, Hockley, Howard, Kent, Lubbock, Lynn, Martin, Motley, Terry, and Yoakum counties; all land in Borden County lying west of a line seven miles west of the Scurry County line running south from the Garza County line to the Howard County line; that area of Midland County north of a line 15 miles south of Interstate 20 running from the Ector County line east to the Glasscock County line; and other areas as proposed by the commissioner by rule for inclusion in the zone and approved by referendum in the area to be added.
(f) The Southern Rolling Plains Eradication Zone consists of Coke, Coleman, Concho, Irion, McCulloch, Runnels, Schleicher, and Tom Green counties, all land in Taylor County lying west of U.S. Highway 83 from a point commencing at the intersection of U.S. Highway 83 and the south Taylor County line, north of the town of Bradshaw; thence all the land lying south of Farm-to-Market Road 1086, as the farm-to-market road proceeds west and north to its intersection with U.S. Highway 277, being all land lying south of the farm-to-market road and east of U.S. Highway 277 from the intersection of Farm-to-Market Road 1086 and U.S. Highway 277 to the point where U.S. Highway 277 intersects the south boundary line of Taylor County, and other areas as proposed by the commissioner by rule for inclusion in the zone and approved by referendum in the area to be added.