Tex. Health & Safety Code § 772.514
The digits 9-1-1 are the primary emergency telephone number in a district. A public safety agency whose services are available through a 9-1-1 system:
Added by Acts 2013, 83rd Leg., R.S., Ch. 552 (S.B. 628), Sec. 1, eff. September 1, 2013.