Tex. Water Code § 49.104

(a) Notwithstanding the provisions and requirements of the Election Code and general laws, any two or more districts situated in the same county and in which substantially all of the land is being or has been developed as part of a single community development plan and which are served by common water supply and waste disposal systems may by mutual agreement designate a common election office and common early and regular polling places within one or more of the districts, but outside the boundaries of one or more of the districts, for the conduct of director election proceedings and early and regular balloting in director elections. This alternative election procedure may only be used if the common election office and polling places so designated:

(1) are within buildings open to the public;

(2) are within the boundaries of at least one of the districts;

(3) meet the requirements of the Election Code and general laws as polling places; and

(4) are located not more than five miles from any portion of the boundaries of any of the participating districts.

(b) Such districts may also agree on and designate a common election officer and common early and regular voting officials for some or all of the director elections to be simultaneously conducted at a common location, any of whom may be nonelective employees of one or more of the districts, so long as the early and regular voting officials are qualified voters within at least one of the districts.