The commissioners court of a county may contract with a private vendor to provide for the financing, design, construction, leasing, operation, purchase, maintenance, or management of a jail, detention center, work camp, or related facility. The commissioners court may not award a contract under this section unless the commissioners court requests proposals by public notice and not less than 30 days from such notice receives a proposal that meets or exceeds the requirements specified in the request for proposals. Before the commissioners court of a county enters into a contract under this section, the commissioners court of the county must receive the written approval of the sheriff of the county, which written approval shall not be unreasonably withheld, or if the county has a population of 2.8 million or more:
Tex. Loc. Gov't. Code § 351.102