The Gulf Intracoastal Waterway (GIWW) is the portion of the Intracoastal Waterway located along the Gulf Coast of the United States. It is a navigable inland waterway running approximately from St. Marks, Florida, to Brownsville, Texas.
The waterway provides a channel with a controlling depth of , designed primarily for barge transportation. Although the U.S. government proposals for such a waterway were made in the early 19th century, the Gulf Intracoastal Waterway was not completed until 1949.
EHL & WHL mileages
Locations along the Gulf Intracoastal Waterway are defined in terms of statute miles (as opposed to nautical miles, in which most marine routes are measured) east and west of Harvey Lock, a navigation lock in the New Orleans area located at . The Hathaway Bridge in Panama City, Florida, for example, is at mile 284.6 EHL (East of Harvey Lock). The Queen Isabella Causeway Bridge at South Padre Island is at mile 665.1 WHL (West of Harvey Lock).
Connecting waterways
The Gulf Intracoastal Waterway crosses or meets, and in some cases is confluent with, numerous other navigable rivers and waterways. They include:
Apalachicola River Arroyo Colorado Atchafalaya River Bayou Lafourche Bayou Terrebonne Calcasieu River Calcasieu Ship Channel Delcambre Canal Houston Ship Channel Industrial Canal Lower Mississippi River Mississippi River-Gulf Outlet Canal Mobile Bay (connecting to the Tenn-Tom Waterway) Pearl River Sabine-Neches Waterway (Includes portions of) Neches River Sabine Lake Sabine River Santa Rosa Sound The Rigolets Vermilion River
Operations and Cargo
As of 2018, The GIWW was the 3rd busiest waterway in the U.S. in terms of tonnage, behind the Mississippi River and the Ohio River. The 112 million tons shipped, worth $90 billion, included 69 million tons of petroleum and petroleum products and 23 million tons of chemicals.
Ports and harbors
Many of the busiest ports in the United States in terms of tons of cargo are located on or near the Gulf Intracoastal Waterway. Notable ports on or near the waterway include:
Florida Apalachicola, Florida Carrabelle, Florida Panama City, Florida Pensacola, Florida
Alabama Mobile, Alabama - Ranked 11th busiest
Mississippi Gulfport, Mississippi Pascagoula, Mississippi - Ranked 29th busiest
Louisiana Baton Rouge, Louisiana - Ranked 7th busiest Houma, Louisiana - Intracoastal City, Louisiana Lake Charles, Louisiana - As of mid-2024 ranked 10th busiest. The GIWW has the Calcasieu Lock just east of Lake Charles. The three-fold purpose is to facilitate navigation, provide flood relief, and prevent possible saltwater intrusion into the Mermentau River Basin. Larose, Louisiana Morgan City, Louisiana New Orleans, Louisiana - Ranked 5th busiest Port Allen, Louisiana Port of South Louisiana - Ranked 2nd busiest Port of Plaquemines - Ranked 12th busiest
Texas Beaumont, Texas - Ranked 8th busiest Brownsville, Texas Corpus Christi, Texas - Ranked 3rd busiest Port Freeport, Texas - Ranked 16th busiest Galveston, Texas - Ranked 46th busiest Houston, Texas - Ranked as busiest port in the United States Port Arthur, Texas - Ranked 15th busiest Port Lavaca - Point Comfort, Texas Texas City, Texas - Ranked 20th busiest Victoria, Texas
See also IHNC Lake Borgne Surge Barrier Gulf Intracoastal Waterway West Closure Complex
References
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