Texas One-Call Law, (Utilities Code Title 5, Chapter 251)
http://tlo2.tlc.state.tx.us/statutes/docs/UT/content/htm/ut.005.00.000251.00.htm#251.001.00
The following changes made by the 77th Texas Legislature (2001) are incorporated in the above link:
House Bill 1699
House Bill 2391