When TRA was created by the state legislature, it was assigned three primary functions. The first function was the creation and maintenance of a basin wide master plan for the Trinity River watershed.

The second major function assigned by the legislature was serving as a local sponsor for federal water projects. The authority has successfully sponsored four US Army Corps of Engineers multiple-purpose water resource projects.

The third function assigned by the Texas Legislature was providing water and wastewater related services within the Trinity River Authority territory.

Services currently provided by TRA include wastewater treatment, water treatment (potable water production), reservoir facilities, recreation facilities and functioning as a conduit for tax exempt financing for cities for water and wastewater treatment facilities;
and for industry in the areas of air and/or water pollution control.

The Authority exists without the benefit of a direct tax base or state and federal appropriations. TRA provides services only to parties requesting service and only to the degree that service is actually delivered. If the revenues for an operating project exceed the expenditures, the surplus is returned to the customer entities served by that project in the form of cash or credit toward next year’s billings.