Through the police powers reserved to them by the 10th Amendment of the Constitution,states have the authority to protect the health, safety, morals, and general welfare of the people. The power to implement public health control measures, including quarantine and isolation, is a well-established exercise of state police power.

DSHS has the authority, with reasonable cause to believe an individual has been exposed to or infected by a communicable disease, to order the person to submit to control measures. The order must be written and delivered in person or via registered or certified mail and remains in effect until the individual is no longer infected or until expiration of the longest usual incubation period for the suspected disease

The DSHS Commissioner may establish an area quarantine if there is a communicable disease outbreak in the state. There must be reasonable cause to believe the individuals or property involved have been infected or contaminated. If needed to cover the impacted area, DSHS may enter into cooperative agreements with neighboring states to share information and coordinate control measures. DSHS must publish notice of the area quarantine in a newspaper of general circulation each week and may use all other reasonable means to inform persons in the area of the quarantine and needed actions. DSHS may also, during a Public Health Disaster, request the disclosure of an individual’s immunization records and take appropriate actions if the person is not adequately immunized. A peace officer, including a sheriff or constable, may use reasonable force to secure a quarantine area and prevent an individual from entering or leaving the quarantine area

https://www.scribd.com/document/452...mergencies-A-Texas-Bench-Book#from_embed

If you care to educate yourself of the Texas Supreme Court's take on current state and federal law regarding the issue.