30 Tex. Admin. Code § 35.801
The commission or executive director may issue emergency orders under Texas Water Code, § 5.515, to authorize immediate action for the addition, replacement, or repair of facilities or control equipment, or the repair or replacement of roads, bridges, or other infrastructure, and authorizing associated emissions of air contaminants, whenever a catastrophe necessitates such construction and emissions otherwise precluded under the Texas Clean Air Act. For purposes of this section, a catastrophe is an unforeseen event including, but not limited to, an act of God, an act of war, severe weather conditions, explosions, fire, or other similar occurrences beyond the reasonable control of the applicant, which renders a facility or its functionally related appurtenances, or a road, bridge, or other infrastructure, inoperable.
30 Tex. Admin. Code § 35.801