Tex. Parks & Wild. Code § 13.307

To obtain the benefits of outdoor recreation programs under this subchapter, the department shall coordinate its activities with and represent the interests of all agencies and political subdivisions of the state as a part of a state plan. The state plan shall include cities, counties, water districts, river authorities, and special districts in outdoor recreation having interests in the planning, development, acquisition, operation, and maintenance of outdoor recreation resources and facilities.