In Texas, orders for quarantine and isolation can be issued by local health authorities, the Department of State Health Services, and other government entities. Quarantine and isolation orders can be issued for individual people as well as geographic areas.
There are many overlapping state and local laws that discuss enforcement of quarantine, isolation, "stay at home," and "shelter in place" orders. Below we've collected a small number of laws related to enforcing orders that have been declared for geographic areas and individual people or groups. The list is not comprehensive.
State law gives the state government and local governments the authority to create penalties for violations of emergency management plans. You should check the details of the orders in your area to find the specific control measures in place and any potential consequences for violation of those measures.
Though there is debate concerning the interpretation of the U.S. Constitution, generally speaking, the federal government has the authority to issue quarantines related to interstate activities as well as entry and exit through the nation's borders. See the CDC's page on quarantine law for more information.