The Gulf Intracoastal Waterway (GIWW) runs parallel to the Gulf of Mexico’s coastline, stretching more than 1,100 miles from St. Marks, Florida, to the southernmost tip of Texas in Brownsville. This shallow-draft, man-made channel is only 12-feet deep and 125-feet wide but it is an integral part of the inland waterway transportation system in the United States.
The GIWW is the third-busiest inland waterway in the United States. Nearly 285,000 vessels carrying more than 110 million short tons of cargo traveled on the waterway in 2018. The GIWW is uniquely positioned to link the ports along the Gulf Coast to major inland ports, such as Memphis, Chicago and Pittsburgh, via the Mississippi River and her tributaries. It also provides a means to connect domestic barge traffic with ocean-going vessel thereby making this waterway central to both intrastate and foreign trade in the United States.
In Texas, the main channel of the Gulf Intracoastal Waterway (GIWW-T) stretches 379 miles along the coastline from the Sabine River at the border with Louisiana to Brownsville, Texas. The channel serves as the backbone of the state’s inland water transportation system connecting Texas’ 11 deep-draft and eight shallow-draft public ports, as well as numerous private facilities via its many tributaries and intersecting ship channels. Though only about one-third of the total length of the GIWW, the Texas segment handled more than 70 percent of all GIWW traffic in 2018—more than 77.7 million shorts tons.
The GIWW’s location on the Gulf of Mexico has a tremendous impact on the types of commodities that are shipped on the waterway. The Gulf Coast is home to 45 percent of U.S. refining capacity, as well as 51 percent of total United States natural gas processing capacity. Consequently, more than 60 percent of the commodities that transit the GIWW are classified as petroleum or petroleum-products and an additional 20 percent are classified as chemicals and related products. Other commodities include crude materials, primary manufactured goods, coal and food and farm products.
The movement of these commodities is a vital component of Texas’ economy. In 2016, freight movement in Texas contributed to 2.2 million full-time jobs, $145 billion in wages, and $215 billion in Gross State Product. Though the percentage of freight that travels on the GIWW is small when compared to other modes of transportation, such as truck or rail, the waterway plays an important role in reducing landside congestion and increasing safety. It contributes to an efficient and cost-effective multimodal transportation system that connects rural regions with urban population centers, provides for the delivery of raw materials and the shipment of finished goods and links areas of economic activity and production with centers of consumption.
The GIWW Legislative Report to the 87th Texas Legislature provides more information about the impact of the Gulf Intracoastal Waterway on Texas and makes recommendations for legislative action.