Zoning in the ETJ in Texas: Texas Local Government Code ?212.003 prohibits municipalities from zoning in the ETJ. In specifies that unless otherwise authorized by state law, a municipality can not regulate the following in its extraterritorial jurisdiction:
(1) the use of any building or property for business, industrial, residential, or other purposes;
(2) the bulk, height, or number of buildings constructed on a particular tract of land;
(3) the size of a building that can be constructed on a particular tract of land, including without limitation any restriction on the ratio of building floor space to the land square footage; or
(4) the number of residential units that can be built per acre of land

Texas Legislature Online, Texas Statutes, Local Government Code ?212.003, (visited 7/23/07)

Subdivision Plats in the EJT in Texas

Generally, municipalities may extend into the ETJ the application of subdivision and other municipal ordinances relating to access to public roads or the pumping, extraction, and use of groundwater by persons other than retail public utilities for the purpose of preventing the use or contact with groundwater that presents an actual or potential threat to human health. Id. at ?212.003. However, certain cities and counties are required to develop written agreements that provide developers of land unified platting review in the extraterritorial jurisdiction (ETJ) of cities. Texas Local Gov’t Code ?212.0025 (“The authority of a municipality under this chapter relating to the regulation of plats or subdivisions in the municipality's extraterritorial jurisdiction is subject to any applicable limitation prescribed by an agreement under Section 242.001.”) Section 242.001(d), Local Government Code, provides that a city and a county may agree that either the county or city may be granted exclusive jurisdiction to regulate subdivision plats and to approve related permits in the ETJ, or they may apportion the ETJ so that the city regulates in some areas and the county regulates in the other areas. A fourth option is also possible: the city and county may establish uniform regulations and a joint office to provide a single point of contact for subdivision regulation in the ETJ.

See Texas Muncipal League Website, HB 1445: Mandated City-County Agreement on ETJ Platting http://www.tml.org This requirement does not apply to counties containing the ETJ of a city with a population of 1.9 million or more (Harris, Fort Bend, Liberty, Montgomery, and Walker), those within 50 miles of an international border or those defined as economically distressed (Andrews, Bee, Brewster, Brooks, Cameron, Coleman, Crane, Crockett, Crosby, Culberson, Dimmit, Duval,Edwards, El Paso, Frio, Grimes, Hall, Hidalgo, Hudspeth, Jeff Davis, Jim Hogg, Jim Wells, Kenedy, Kinney, Kleberg, La Salle, Leon, Liberty, Marion, Maverick, Mitchell, Newton, Nolan, Panola, Pecos, Presidio, Reagan, Reeves, San Augustine, San Patricio, Scurry, Starr, Sutton, Terrell, Tyler, Upshur, Upton, Uvalde, Val Verde, Ward, Webb, Willacy, Winkler, Zapata, and Zavala). Id.