The authority extends over 17,965 square miles (46,529 km2), including all or part of 17 counties.

TRA is a self-funded entity from its operations; it receives no state appropriations or taxes.

TRA is governed by a 25-member board of directors, all of whom are appointed by the Governor of Texas for six-year terms.

The board, in turn, hires the General Manager, who oversees TRA's operations.

Under the statute creating the TRA, the board members are appointed as follows: Since 1911, 31 major reservoirs have been constructed in the drainage basin of the Trinity River, 29 of which fall under the jurisdiction of the Trinity River Authority.