Tex. Auxiliary Water Laws § 7830

Where a proposed district lies partly within two or more counties, the petition for the establishment of said district shall be presented to the commissioners court of each county. Each such court shall give all necessary notice as provided for a single district in one county, but stating that same is a part of such entire district, and shall order an election, appoint all necessary officers, furnish all supplies, canvass the returns and declare the result of such election, all as provided for a single district. The presiding officer of each court shall then certify and report the result of said election to the county judge of the county in which the largest portion of such district is situated.