Tex. Spec. Dist. Local Laws Code § 9067.053

Under Section 52, Article III, Texas Constitution, the district may design, acquire, construct, finance, issue bonds for, improve, operate, maintain, and convey to this state, a county, a municipality, or a public improvement district within a municipality for operation and maintenance macadamized, graveled, or paved roads, or improvements, including storm drainage, lakes, reservoirs, canals, underground drainage, and water treatment systems, in aid of those roads.