TX NATURAL RESOURCES CODE

SUBTITLE B. SURVEYS AND SURVEYORS

CHAPTER 21. SURVEYS AND FIELD NOTES

SUBCHAPTER D. TEXAS COORDINATE SYSTEMS


§ 21.071. ADOPTION OF COORDINATE SYSTEMS.
     (a) The systems of plane coordinates which have been established by the National Oceanic Survey/National Geodetic Survey for defining and stating the positions or locations of points on the surface of the earth within the State of Texas are adopted and will be known and designated as the Texas Coordinate System of 1927 and the Texas Coordinate System of 1983.
     (b) Each system is a separate system and must be used as a separate system.

Acts 1977, 65th Leg., p. 2357, ch. 871, art. I, § 1, eff. Sept. 1, 1977. Amended by Acts 1987, 70th Leg., ch. 616, § 3, eff. Sept. 1, 1987.

§ 21.072. PURPOSE AND LIMITATIONS OF COORDINATE SYSTEMS.
     (a) The only purpose for adopting the Texas Coordinate
      System of 1927 and the Texas Coordinate System of 1983 is to recognize a system for use in the State of Texas to definitely ascertain positions on the surface of the earth.
     (b) Except as provided in Section 21.041 of this code, the use of a system is not required, and the provisions of this subchapter shall not be construed to set aside or disturb any corner or survey already established.
     (c) The use of the term "Texas Coordinate System" on a map, report, survey, or other document is limited to coordinates based on a Texas Coordinate System as defined in this subchapter.

Acts 1977, 65th Leg., p. 2357, ch. 871, art. I, § 1, eff. Sept. 1, 1977. Amended by Acts 1985, 69th Leg., ch. 624, § 2, eff. Sept. 1, 1985; Acts 1987, 70th Leg., ch. 616, § 4, eff. Sept. 1, 1987.

§ 21.073. DIVISION OF STATE INTO ZONES.
     For the purpose of using a system, the state is divided into five zones:
          (1) the North Zone;
          (2) the North Central Zone;
          (3) the Central Zone;
          (4) the South Central Zone; and
          (5) the South Zone.

Acts 1977, 65th Leg., p. 2357, ch. 871, art. I, § 1, eff. Sept. 1, 1977. Amended by Acts 1987, 70th Leg., ch. 616, § 5, eff. Sept. 1, 1987.

§ 21.074. AREA WITHIN ZONES.
     (a) The area included in the following counties constitutes the North Zone: Armstrong, Briscoe, Carson, Castro, Childress, Collingsworth, Dallam, Deaf Smith, Donley, Gray, Hall, Hansford, Hartley, Hemphill, Hutchinson, Lipscomb, Moore, Ochiltree, Oldham, Parmer, Potter, Randall, Roberts, Sherman, Swisher, and Wheeler.
     (b) The area included in the following counties constitutes the North Central Zone: Andrews, Archer, Bailey, Baylor, Borden, Bowie, Callahan, Camp, Cass, Clay, Cochran, Collin, Cooke, Cottle, Crosby, Dallas, Dawson, Delta, Denton, Dickens, Eastland, Ellis, Erath, Fannin, Fisher, Floyd, Foard, Franklin, Gaines, Garza, Grayson, Gregg, Hale, Hardeman, Harrison, Haskell, Henderson, Hill, Hockley, Hood, Hopkins, Howard, Hunt, Jack, Johnson, Jones, Kaufman, Kent, King, Knox, Lamar, Lamb, Lubbock, Lynn, Marion, Martin, Mitchell, Montague, Morris, Motley, Navarro, Nolan, Palo Pinto, Panola, Parker, Rains, Red River, Rockwall, Rusk, Scurry, Shackelford, Smith, Somervell, Stephens, Stonewall, Tarrant, Taylor, Terry, Throckmorton, Titus, Upshur, Van Zandt, Wichita, Wilbarger, Wise, Wood, Yoakum, and Young.
     (c) The area included in the following counties constitutes the Central Zone: Anderson, Angelina, Bastrop, Bell, Blanco, Bosque, Brazos, Brown, Burleson, Burnet, Cherokee, Coke, Coleman, Comanche, Concho, Coryell, Crane, Crockett, Culberson, Ector, El Paso, Falls, Freestone, Gillespie, Glasscock, Grimes, Hamilton, Hardin, Houston, Hudspeth, Irion, Jasper, Jeff Davis, Kimble, Lampasas, Lee, Leon, Liberty, Limestone, Llano, Loving, McLennan, McCulloch, Madison, Mason, Menard, Midland, Milam, Mills, Montgomery, Nacogdoches, Newton, Orange, Pecos, Polk, Reagan, Reeves, Robertson, Runnels, Sabine, San Augustine, San Jacinto, San Saba, Schleicher, Shelby, Sterling, Sutton, Tom Green, Travis, Trinity, Tyler, Upton, Walker, Ward, Washington, Williamson, and Winkler.
     (d) The area included in the following counties constitutes the South Central Zone: Aransas, Atascosa, Austin, Bandera, Bee, Bexar, Brazoria, Brewster, Caldwell, Calhoun, Chambers, Colorado, Comal, DeWitt, Dimmit, Edwards, Fayette, Fort Bend, Frio, Galveston, Goliad, Gonzales, Guadalupe, Harris, Hays, Jackson, Jefferson, Karnes, Kendall, Kerr, Kinney, LaSalle, Lavaca, Live Oak, McMullen, Matagorda, Maverick, Medina, Presidio, Real, Refugio, Terrell, Uvalde, Val Verde, Victoria, Waller, Wharton, Wilson, and Zavala.
     (e) The area included in the following counties constitutes the South Zone: Brooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells, Kenedy, Kleberg, Nueces, San Patricio, Starr, Webb, Willacy, and Zapata.

Acts 1977, 65th Leg., p. 2357, ch. 871, art. I, § 1, eff. Sept. 1, 1977.

§ 21.075. ZONE NAMES IN LAND DESCRIPTION.
     (a) As established for use in the North Zone, the Texas Coordinate System of 1927 or the Texas Coordinate System of 1983 shall be named, and in any land description in which it is used it shall be designated, the "Texas Coordinate System of 1927, North Zone" or "Texas Coordinate System of 1983, North Zone."
     (b) As established for use in the North Central Zone, the Texas Coordinate System of 1927 or the Texas Coordinate System of 1983 shall be named, and in any land description in which it is used it shall be designated, the "Texas Coordinate System of 1927, North Central Zone" or "Texas Coordinate System of 1983, North Central Zone."
     (c) As established for use in the Central Zone, the Texas Coordinate System of 1927 or the Texas Coordinate System of 1983 shall be named, and in any land description in which it is used it shall be designated, the "Texas Coordinate System of 1927, Central Zone" or "Texas Coordinate System of 1983, Central Zone."
     (d) As established for use in the South Central Zone, the Texas Coordinate System of 1927 or the Texas Coordinate System of 1983 shall be named, and in any land description in which it is used it shall be designated, the "Texas Coordinate System of 1927, South Central Zone" or "Texas Coordinate System of 1983, South Central Zone."
     (e) As established for use in the South Zone, the Texas Coordinate System of 1927 or the Texas Coordinate System of 1983 shall be named, and in any land description in which it is used it shall be designated, the "Texas Coordinate System of 1927, South Zone" or "Texas Coordinate System of 1983, South Zone."

Acts 1977, 65th Leg., p. 2358, ch. 871, art. I, § 1, eff. Sept. 1, 1977. Amended by Acts 1987, 70th Leg., ch. 616, § 6, eff. Sept. 1, 1987.

§ 21.076. DEFINITIONS.
     (a) For the purpose of precisely defining the Texas Coordinate System of 1927 and the Texas Coordinate System of 1983, the following definitions are adopted:
          (1) The Texas Coordinate System of 1927, North Zone, and the Texas Coordinate System of 1983, North Zone, is a Lambert conformal projection, having standard parallels at north latitudes 34° 39' and 36° 11', along which parallels the scale shall be exact. The origin of coordinates is at the intersection of the meridian 101° 30' west longitude and the parallel 34° 00' north latitude. The origin of the 1927 coordinate system is given the coordinates: x = 2,000,000 feet (720,000 varas) and y = 0 feet (0 varas). The origin of the 1983 coordinate system is given the coordinates: x = 200,000 meters (236,220 varas) and y = 1,000,000 meters (1,181,100 varas).
          (2) The Texas Coordinate System of 1927, North Central Zone, and the Texas Coordinate System of 1983, North Central Zone, is a Lambert conformal projection, having standard parallels at north latitudes 32° 08' and 33° 58', along which parallels the scale shall be exact. The origin of coordinates for the 1927 coordinate system is at the intersection of the meridian 97° 30' west longitude and the parallel 31° 40' north latitude. This origin is given the coordinates: x = 2,000,000 feet (720,000 varas) and y = 0 feet (0 varas). The origin of coordinates for the 1983 coordinate system is at the intersection of the meridian 98° 30' west longitude and the parallel 31° 40' north latitude. This origin is given the coordinates: x = 600,000 meters (708,660 varas) and y = 2,000,000 meters (2,362,200 varas).
          (3) The Texas Coordinate System of 1927, Central Zone, and the Texas Coordinate System of 1983, Central Zone, is a Lambert conformal projection, having standard parallels at north latitudes 30° 07' and 31° 53', along which parallels the scale shall be exact. The origin of coordinates is at the intersection of the meridian 100° 20' west longitude and the parallel 29° 40' north latitude. The origin of the 1927 coordinate system is given the coordinates: x = 2,000,000 feet (720,000 varas) and y = 0 feet (0 varas). The origin of the 1983 coordinate system is given the coordinates: x = 700,000 meters (826,770 varas) and y = 3,000,000 meters (3,543,300 varas).
          (4) The Texas Coordinate System of 1927, South Central Zone, and the Texas Coordinate System of 1983, South Central Zone, is a Lambert conformal projection, having standard parallels at north latitudes 28° 23' and 30° 17', along which parallels the scale shall be exact. The origin of coordinates is at the intersection of the meridian of 99° 00' west longitude and the parallel 27° 50' north latitude. The origin of the 1927 coordinate system is given the coordinates: x = 2,000,000 feet (720,000 varas) and y = 0 feet (0 varas). The origin of the 1983 coordinate system is given the coordinates: x = 600,000 meters (708,660 varas) and y = 4,000,000 meters (4,724,400 varas).
          (5) The Texas Coordinate System of 1927, South Zone, and the Texas Coordinate System of 1983, South Zone, is a Lambert conformal projection, having standard parallels at north latitudes 26° 10' and 27° 50', along which parallels the scale shall be exact. The origin of coordinates is at the intersection of the meridian 98° 30' west longitude and the parallel 25° 40' north latitude. The origin of the 1927 coordinate system is given the coordinates: x = 2,000,000 feet (720,000 varas) and y = 0 feet (0 varas). The origin of the 1983 coordinate system is given the coordinates: x = 300,000 meters (354,330 varas) and y = 5,000,000 meters (5,905,500 varas).
     (b) The position of the Texas Coordinate System of 1927 and the Texas Coordinate System of 1983 shall be as marked on the ground by triangulation or traverse stations established in conformity with the standards adopted by the National Oceanic and Atmospheric Administration for first-order and second-order work, whose geodetic positions have been rigidly adjusted on the North American datum of 1927 or 1983, and whose coordinates have been computed on the system defined in this subchapter. Any of these stations may be used for establishing a survey connection with the Texas Coordinate System of 1927 or the Texas Coordinate System of 1983.

Acts 1977, 65th Leg., p. 2358, ch. 871, art. I, § 1, eff. Sept. 1, 1977. Amended by Acts 1987, 70th Leg., ch. 616, § 7, eff. Sept. 1, 1987.

§ 21.077. UNIT OF MEASUREMENT.
     The unit of measurement in this subchapter has the following values, based on the International Meter established by the National Bureau of Standards:
          (1) one meter = 39.37 inches exactly;
          (2) one foot = 12.00 inches exactly; and
          (3) one vara = 33-1/3 inches exactly.

Acts 1977, 65th Leg., p. 2359, ch. 871, art. I, § 1, eff. Sept. 1, 1977.

§ 21.078. TERMS "X COORDINATE" AND "Y COORDINATE".
     (a) The plane coordinate values for a point on the earth's surface, to be used in expressing the position or location of the point in the appropriate zone, of either system, shall consist of two distances, expressed in U.S. Survey Feet and decimals of a foot or varas or tenths of a vara when using the Texas Coordinate System of 1927 and expressed in meters and decimals of a meter, in U.S. Survey Feet or decimals of a foot, or in varas or tenths of a vara when using the Texas Coordinate System of 1983.
     (b) One of these distances, to be known as the "x coordinate," shall give the position in an east-and-west direction; the other, to be known as the "y coordinate," shall give the position in a north-and-south direction.
     (c) These coordinates shall be made to depend on and conform to the plane rectangular coordinate values for the monumented points of the North American Horizontal Geodetic Control Network as published by the National Oceanic Survey/National Geodetic Survey, or its successors, and whose plane coordinates have been computed on the systems defined in this subchapter.
     (d) Any station described in this section may be used for establishing a survey connection to either the Texas Coordinate System of 1927 or the Texas Coordinate System of 1983.

Acts 1977, 65th Leg., p. 2359, ch. 871, art. I, § 1, eff. Sept. 1, 1977. Amended by Acts 1987, 70th Leg., ch. 616, § 8, eff. Sept. 1, 1987; Acts 1993, 73rd Leg., ch. 991, § 4, eff. Sept. 1, 1993.

§ 21.079. LAND IN MORE THAN ONE ZONE.
     If a tract of land to be defined by a single description extends from one zone into another of the coordinate zones, the positions of all points on its boundaries may be referred to by either of the zones, the zone which is used being specifically named in the description.

Acts 1977, 65th Leg., p. 2360, ch. 871, art. I, § 1, eff. Sept. 1, 1977. Amended by Acts 1987, 70th Leg., ch. 616, § 9, eff. Sept. 1, 1987.