A person may not engage in a business, occupation, or profession described by Section 26.0301, 26.3573, 26.452, or 26.456 of this code, Section 341.033, 341.034, 361.027, 366.014, or 366.071, Health and Safety Code, or Section 1903.251, Occupations Code, unless the person holds the appropriate license or registration issued by the commission.
Tex. Water Code § 37.003