Tex. Gov't Code § 24.944

The board shall reapportion the judicial districts authorized by Article V, Section 7, of the Texas Constitution by statewide reapportionment of the districts and, as the necessity for additional reapportionment appears, by redesignating, in one or more reapportionment orders, the county or counties that comprise the specific judicial districts affected by those reapportionment orders. The board shall investigate from time to time the necessity of and appropriate locations for new judicial districts and shall advise the legislature of its findings. The board shall inform itself on all matters bearing on its duties.