Gulf Intracoastal Waterway - Louisiana Route Segment

Lake Borgne, LA to Sabine River, LA

Louisiana’s section of the Gulf Intracoastal Waterway (GICW) begins near the mouth of the Pearl River, MS near (MM "41.0 EHL") at 30°15.042’ N / 88°23.666’ W in Lake Borgne.

From Lake Borgne, this section of the GICW runs generally in a westerly direction for 307.0 miles ending at 30°03.2’ N / 93°43.2’ W (MM "266.0 WHL") on the Sabine River at the Texas state line.



Louisiana’s GICW is marked with your standard Aids to Navigation which also display yellow triangles or yellow squares. When westbound along Louisiana’s Gulf Intracoastal Waterway, marks displaying yellow triangles should be kept on your starboard hand and those marked with yellow squares should be kept to port.

While typically the yellow triangles will be found on red markers and yellow squares are found on green markers, caution should be exercised along this route in the vicinity of the Mississippi River, Lower Atchafalaya River, Vermilion River, and Calcasieu River where the GICW intersects or coincides with the channels marked by the Lateral Buoyage System.


NOAA chart coverage of this portion of the GICW beginning at (MM “41.0 EHL”) to (MM "266.0 WHL" is provided by charts #11367, #11365, #11355, #11350, #11348, and #11331. These charts can be viewed by clicking on the links below:

Chart #11367 - Waveland to Catahoula Bay
Chart #11365 - Barataria and Bayou Lafourche Waterways
Chart #11355 - Catahoula Bay to Wax Lake Outlet
Chart #11350 - Wax Lake Outlet to Forked Island
Chart #11348 - Forked Island to Ellender
Chart #11331 - Ellender to Galveston Bay

Distances and Mileages

All distances along the Louisiana’s Gulf Intracoastal Waterway are given in statute miles unless otherwise noted. Statute miles are used in order to conform to the distances shown on the small craft charts typically used along this route.

This portion of the GICW between the Mississippi State line and the Texas State line is measured based on both decreasing and increasing mileage East and West of Harvey Lock from (MM "41.0 EHL") to (MM "266.0 WHL").


The Federal project depth for the Louisiana portion of the Gulf Intracoastal Waterway provides for a minimum channel depth of 12 feet. Even though every effort is made to maintain the project depth, the actual controlling depths in the channels may vary due to shoaling reducing the available water depth until maintenance dredging can be accomplished.


Bridges, Locks, & Overhead Power Lines


Gulf Intracoastal Waterway Bridges - Louisiana (GIWW)

The Rigolets to New Orleans

Mile Marker Bridge Charted Vert. Clear. Schedule Restrictions VHF
13.0 EHL Paris Road Bridge 137’ Fixed Bridge    
7.5 EHL Florida Avenue Lift Bridge 0’/156’ Opens on Demand Closed 0630-0830 & 1530-1745 Mon.-Fri. Excl. Federal Holidays. 13
6.7 EHL Inner Harbor Lift Bridge 40’/156’ Opens on Demand Closed 0630-0830 & 1530-1745 Mon.-Fri. Excl. Federal Holidays. 13
6.2 EHL St. Claude Avenue Bascule Bridge 0’/70’ Opens on Demand Closed 0630-0830 & 1530-1745 Mon.-Fri. Excl. Federal Holidays. 13
2.5 EHL Crescent City Connector Bridge 150’ Fixed Bridges Twin Spans  

Gulf Intracoastal Waterway Bridges - Louisiana (GIWW)

New Orleans to Morgan City

Mile Marker Bridge Charted Vert. Clear. Schedule Restrictions VHF
0.1 WHL Union Pacific RR Bascule Bridge 7’ Opens on Demand   13
0.15 WHL 4th Street Bascule Bridge 7’ Opens on Demand   13
0.8 WHL West Bank Expressway 95’ Fixed Bridge Twin Spans  
2.8 WHL Lapalco Blvd. Bascule Bridge 45’ Opens on Demand Closed Mon.-Fri. 0630-0830 and from 1545-1745 except holidays. 09
11.9 WHL Crown Point Bridge 73’ Fixed Bridge    
35.0 WHL SR 308 Bridge 73’ Fixed Bridge    
35.7 WHL 5th Street Lift Bridge 35’ / 73’ Opens on Demand   13
49.8 WHL Bayou Blue Road Pontoon Bridge 0’ Opens on Demand   13
54.4 WHL Prospect Blvd. Bridge 73’ Fixed Bridge    
57.6 WHL Park Avenue Bridge 73’ Fixed Bridge    
57.7 WHL Main Street Bridge 73’ Fixed Bridge    
59.9 WHL Bayou Dularge Bascule Bridge 40’ On Demand Closed Mon.-Fri. from 0630-0830, 1145-1215, 1245-1315 and from 1630-1800 except Fed. holidays. 13

Gulf Intracoastal Waterway Bridges - Louisiana (GIWW)

Morgan City to Port Arthur

Mile Marker Bridge Charted Vert. Clear. Schedule Restrictions VHF
113.0 WHL North Bend Bridge 73’ Fixed Bridge    
134.0 WHL Louisa Bascule Bridge 73’ On Demand The draw shall open on signal if at least 24 hours notice is given. 13
170.3 WHL Forked Island Bridge 73’ Fixed Bridge    
219.8 WHL W. Creole Highway Bridge 73’ Fixed Bridge    
231.5 WHL Grand Lake Pontoon Bridge 0’ Opens on Demand   13
238.0 WHL Black Bayou Pontoon Bridge 0’ Opens on Demand   13
243.8 WHL Ellender Lift Bridge 50’/135’ Opens on Demand (4 Hour notice required).   13

The table above lists the bridges, their schedules, and restrictions along Louisiana’s Gulf Intracoastal Waterway from the Pearl River in Louisiana west to the Texas State line.

This list is believed to be accurate as of January 2019. If any errors or omissions are noted, please e-mail us at with any corrections or recommendations.

This bridge operating schedule can be downloaded for your personal and private use as a ZIP file. The file contains the schedule in Adobe (.pdf) file format.

Louisiana Gulf Coast Bridge Schedule - Download


Open Down Arrow GICW - Louisiana Lock Schedule

Louisiana Gulf Intracoastal Waterway Locks

Mile Marker Bridge Charted Vert. Clear. Schedule Restrictions VHF
6.5 EHL Inner Harbor Canal Lock   On Demand Operates within the operating times of the Florida Avenue, Claibourne, and St. Claude operating bridges. 14
0.0 Harvey Lock   On Demand   14
93.0 WHL Bayou Boeuf Lock   On Demand   14
163.0 WHL Leland-Bowman Lock   On Demand   14
238.2 WHL Calcasieu Lock   On Demand Lock will remain closed M-F 0700 to 1700 thru December 2019. Other times on Demand. 13

Overhead Power Lines

Quite a few overhead cables cross Louisiana’s Gulf Intracoastal Waterway. Numerous cable crossings with a minimum authorized clearance noted at 90’ are located between (MM "34.0 WHL") and (MM "135.0 WHL"). (1) overhead cable at (MM "219.9 WHL") has been reported to have a clearance of only 82’.

Caution - Many of the overhead cables over the waterway carry high voltage, and an extra margin of safety should be allowed when the weather is threatening.


Tidal ranges are fairly small along Louisiana’s coast. Under normal conditions the mean range of tide averages between less than 0.5’ at Chef Menteur Pass to about 0.5’ across the remainder of the state to the Texas State line.

Louisiana experiences (2) types of tides; from the Mississippi state line west to Vermilion Bay the type of tide experienced is commonly refered to as a "Diurnal Tide" - exhibiting (1) high tide and (1) low tide each day. West of Vermilion Bay to the Texas State Line, a "Mixed Tide" gradually takes over having (2) unequal high and low tides each day.

Inlets & Passes

There are more than (31) Passes (Inlets) between the Gulf of Mexico and the inside waters of Louisiana. Most of these are only suitable for shallow draft vessels or local knowledge, but some can be considered navigable by most vessels.

Chef Menteur Pass

Chef Menteur Pass, a pass between Lake Borgne and Lake Pontchartrain also intersects the GICW at (MM "22.9 EHL") about 1.7 miles above the entrance. While the pass itself is deep with good water almost bank to bank, the seaward approach to the pass has a least depth of 6 feet. A new Gulf Intracoastal Waterway alignment channel crosses Chef Menteur Pass 1 mile SE of the original Intracoastal Waterway crossing.

Southwest Pass

Southwest Pass, the westernmost of the passes for the Mississippi River. The entrance has jetties on both sides with the East Jetty marked by the Southwest Pass Entrance Light (Fl 10s) and is equipped with a RACON showing (-‧-). The approach channel to Southwest Pass is marked by a lighted buoy Mo (a), 1.6 miles south of the entrance.

Southwest Pass is deep and well-marked by daybeacons and ranges to the Head of Passes. Above the Head of Passes the channel is marked both by daybeacons and a few buoys, but with few exceptions deep water is available bank to bank.

Intersection with the Gulf Intracoastal Waterway happens abeam of the Inner Harbor Navigation Canal 112.6 miles above the entrance.

Atchafalaya Bay Inlet

Atchafalaya Bay Inlet is located between Point au Fer Island to the west and Eugene Island to the west. It is deep (20’) and well-marked by buoys and daybeacons. Point au Fer Light is the most prominent navigation aid in the area.

From the entrance, a dredged channel leads to the Lower Atchafalaya River and on to its intersection with the Gulf Intracoastal Waterway at (MM “98.2 WHL”) 26.9 miles above the entrance.

Calcasieu Pass

Calcasieu Pass is a deep-draft channel leading to Lake Charles, LA. It is deep with a minimum controlling depth of 33’ and is well-marked with buoys, daybeacons and ranges. The entrance is protected by jetties. The approach channel is marked by a fairway buoy RW “CC” showing a Mo (A) white light.

Calcasieu Pass intersects the GICW at (MM “241.5 WHL”) 24 miles above the entrance.

NEXT - GIWW (Texas)

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