Tex. Water Aux. Laws § 7849a

The directors of any Water Control and Preservation District and the engineers and employés thereof are hereby authorized to go upon any land lying within said district for the purpose of examining same for locating dams, bulkheads, jetties, locks, gates or any other character of improvement or construction necessary to the accomplishment of the purposes of the district, to make maps and profiles thereof, and are hereby authorized to go upon lands beyond the boundaries of such districts for the purposes stated and for any other purposes necessarily connected therewith whether herein enumerated or not. Any person who shall wilfully prevent or prohibit any such officer or employé from entering upon such land for such purpose shall be fined one hundred dollars for each day he shall so prevent or prohibit such officer or employé.