The Gulf Intracoastal Waterway (GIWW) is the portion of the Intracoastal Waterway located along the

Gulf Coast of the United States The Gulf Coast of the United States, also known as the Gulf South or the South Coast, is the coastline along the Southern United States where they meet the Gulf of Mexico. The list of U.S. states and territories by coastline, coastal states th ...

. It is a navigable inland waterway running approximately from Saint Marks, Florida, to Brownsville,

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

. The waterway provides a channel with a controlling depth of , designed primarily for

barge A barge is typically a flat-bottomed boat, flat-bottomed vessel which does not have its own means of mechanical propulsion. Original use was on inland waterways, while modern use is on both inland and ocean, marine water environments. The firs ...

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 mile A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude at t ...

s, in which most marine routes are measured) east and west of Harvey Lock, a navigation lock in the

New Orleans New Orleans (commonly known as NOLA or The Big Easy among other nicknames) is a Consolidated city-county, consolidated city-parish located along the Mississippi River in the U.S. state of Louisiana. With a population of 383,997 at the 2020 ...

area located at . The Hathaway Bridge in

Panama City Panama City, also known as Panama, is the capital and largest city of Panama. It has a total population of 1,086,990, with over 2,100,000 in its metropolitan area. The city is located at the Pacific Ocean, Pacific entrance of the Panama Canal, i ...

, Florida, for example, is at mile 284.6 EHL (East of Harvey Lock). The Queen Isabella Causeway Bridge at

South Padre Island South Padre Island is a barrier island in the U.S. state of Texas. The remote landform is located in Cameron County, Willacy County, and accessible by the Queen Isabella Causeway. South Padre Island was formed when the creation of the Port Ma ...

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 The Apalachicola River is a river, approximately long, in the state of Florida. The river's large drainage basin, watershed, known as the ACF River Basin, Apalachicola, Chattahoochee and Flint (ACF) River Basin, drains an area of approximately ...

* Arroyo Colorado * Atchafalaya River * Bayou Lafourche * Bayou Terrebonne *

Calcasieu River The Calcasieu River ( ; ) is a river on the Gulf Coast of the United States, Gulf Coast in southwestern Louisiana. Approximately long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed J ...

* Calcasieu Ship Channel * Delcambre Canal * Houston Ship Channel *

Industrial Canal The Industrial Canal is a waterway in New Orleans, Louisiana, United States. The waterway's proper name, as used by the U.S. Army United States Army Corps of Engineers, Corps of Engineers and on NOAA nautical charts, is Inner Harbor Navigation ...

* Lower Mississippi River * Mississippi River-Gulf Outlet Canal *

Mobile Bay Mobile Bay ( ) is a shallow inlet of the Gulf of Mexico, lying within the state of Alabama in the United States. Its mouth is formed by the Fort Morgan Peninsula on the eastern side and Dauphin Island, a barrier island on the western side. T ...

(connecting to the Tenn-Tom Waterway) * Pearl River * Sabine-Neches Waterway (Includes portions of) ** Neches River **

Sabine Lake Sabine Lake is a bay on the Gulf coasts of Texas and Louisiana, located approximately east of Houston and west of Baton Rouge, Louisiana, Baton Rouge, adjoining the city of Port Arthur, Texas, Port Arthur. The lake is formed by the confluence ...

** Sabine River * Santa Rosa Sound * The Rigolets * Vermilion River

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 Apalachicola ( ) is a city and the county seat of Franklin County, Florida, United States, on the shore of Apalachicola Bay, an inlet of the Gulf of Mexico. The population was 2,341 at the 2020 census. History The Apalachicola Province, a ...

* Carrabelle, Florida * Panama City, Florida *

Pensacola, Florida Pensacola ( ) is a city in the Florida panhandle in the United States. It is the county seat and only incorporated city, city in Escambia County, Florida, Escambia County. The population was 54,312 at the 2020 United States census, 2020 census. ...

Alabama *

Mobile, Alabama Mobile ( , ) is a city and the county seat of Mobile County, Alabama, United States. The population was 187,041 at the 2020 United States census, 2020 census. After a successful vote to annex areas west of the city limits in July 2023, Mobil ...

- Ranked 11th busiest
Mississippi *

Gulfport, Mississippi Gulfport ( ) is a city in Harrison County, Mississippi, United States, and its co-county seat. It had a population of 72,926 at the 2020 United States census, 2020 census, making it the List of municipalities in Mississippi, second-most populous ...

Pascagoula, Mississippi Pascagoula ( ) is a city in and the county seat of Jackson County, Mississippi, United States. It is the principal city of the Pascagoula metropolitan area, and is part of the Gulfport, Mississippi, Gulfport–Biloxi, Mississippi, Biloxi–Pascag ...

- Ranked 29th busiest
Louisiana *

Baton Rouge, Louisiana Baton Rouge ( ; , ) is the List of capitals in the United States, capital city of the U.S. state of Louisiana. It had a population of 227,470 at the 2020 United States census, making it List of municipalities in Louisiana, Louisiana's second-m ...

- 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 New Orleans (commonly known as NOLA or The Big Easy among other nicknames) is a Consolidated city-county, consolidated city-parish located along the Mississippi River in the U.S. state of Louisiana. With a population of 383,997 at the 2020 ...

- Ranked 5th busiest * Port Allen, Louisiana *

Port of South Louisiana The Port of South Louisiana () extends 54 miles (87 km) along the Mississippi River between New Orleans, Louisiana and Baton Rouge, Louisiana, centering approximately at LaPlace, Louisiana, which serves as the Port's headquarters location. ...

- Ranked 2nd busiest * Port of Plaquemines - Ranked 12th busiest
Texas *

Beaumont, Texas Beaumont is a city in the U.S. state of Texas. It is the county seat of Jefferson County, Texas, Jefferson County, within the Beaumont–Port Arthur metropolitan area, located in Southeast Texas on the Neches River about east of Houston (city ...

- Ranked 8th busiest *

Brownsville, Texas Brownsville ( ) is a city in the U.S. state of Texas and the county seat of Cameron County, Texas, Cameron County, located on the western Gulf Coast in South Texas, adjacent to the Mexico–United States border, border with Matamoros, Tamaulipas ...

Corpus Christi, Texas Corpus Christi ( ; ) is a Gulf Coast of the United States, coastal city in the South Texas region of the U.S. state of Texas and the county seat and largest city of Nueces County, Texas, Nueces County with portions extending into Aransas County, T ...

- Ranked 3rd busiest * Port Freeport, Texas - Ranked 16th busiest *

Galveston, Texas Galveston ( ) is a Gulf Coast of the United States, coastal resort town, resort city and port off the Southeast Texas coast on Galveston Island and Pelican Island (Texas), Pelican Island in the U.S. state of Texas. The community of , with a pop ...

- Ranked 46th busiest *

Houston, Texas Houston ( ) is the List of cities in Texas by population, most populous city in the U.S. state of Texas and in the Southern United States. Located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the county seat, seat of ...

- Ranked as busiest port in the United States *

Port Arthur, Texas Port Arthur is a city in the state of Texas, United States of America, located east of metro Houston. Part of the Beaumont–Port Arthur metropolitan area, the city lies primarily in Jefferson County, with a small extension in Orange County. ...

- Ranked 15th busiest * Port Lavaca - Point Comfort, Texas * Texas City, Texas - Ranked 20th busiest *

Victoria, Texas Victoria is a city and the county seat of Victoria County, Texas, United States. The population was 65,534 as of the 2020 United States census, 2020 census. The three counties of the Victoria, Texas metropolitan area, Victoria Metropolitan Statis ...

References

Sources

* * {{Authority control Gulf Gulf Coast of the United States Canals in Alabama Canals in Florida Canals in Louisiana Canals in Mississippi Canals in New Orleans Canals in Texas Canals opened in 1949 1949 establishments in the United States

EHL & WHL mileages

Connecting waterways

Ports and harbors

See also

References

Sources