|Basin countries||United States|
|Max. length||40 mi (64 km)|
|Max. width||24 mi (39 km)|
|Surface area||630 sq mi (1630 km²)|
|Average depth||12-14 feet|
|Max. depth||65 feet (20 m)|
|Settlements||New Orleans, Metairie, Kenner, Mandeville, Slidell, Madisonville.o|
Lake Pontchartrain (pron.: //; French: Lac Pontchartrain, French: [lak pɔ̃ʃaʁtʁɛ̃] ( listen)) is a brackish estuary located in southeastern Louisiana. As an estuary, Pontchartrain is not a true lake. It is, however, among the largest wetlands in the world.
It covers an area of 630 square miles (1,600 km2) with an average depth of 12 to 14 feet (3.7 to 4.3 m). Some shipping channels are kept deeper through dredging. It is roughly oval in shape, about 40 miles (64 km) from west to east and 24 miles (39 km) from south to north. In descending order of area, the lake is located in parts of St. Tammany, Orleans, Jefferson, St. John the Baptist, St. Charles, and Tangipahoa parishes.
Lake Pontchartrain is named for Louis Phélypeaux, comte de Pontchartrain, the French Minister of the Marine, Chancellor of France and Controller-General of Finances during the reign of France's "Sun King," Louis XIV, for whom Louisiana is named.
Lake Pontchartrain is not a true lake but an estuary connected to the Gulf of Mexico via the Rigolets strait (known locally as "the Rigolets") and Chef Menteur Pass into Lake Borgne, another large lagoon, and therefore experiences small tidal changes. It receives fresh water from the Tangipahoa, Tchefuncte, Tickfaw, Amite, and Bogue Falaya rivers, and from Bayou Lacombe and Bayou Chinchuba. It is one of the largest wetlands along the Gulf Coast of North America. There are more than 125,000 ha of wetland, including bottom land hardwoods and cypress swamps (although these have been severely degraded by past logging) along with a complex mixture of herbaceous wetlands including fresh, intermediate and brackish marsh.
Salinity varies from negligible at the northern cusp west of Mandeville up to nearly half the salinity of seawater at its eastern bulge near Interstate 10. Lake Maurepas, a true freshwater lake, connects with Lake Pontchartrain on the west via Pass Manchac. The Industrial Canal connects the Mississippi River with the lake at New Orleans. Bonnet Carré Spillway diverts water from the Mississippi into the lake during times of river flooding.
The lake was created 2,600 to 4,000 years ago as the evolving Mississippi River Delta formed its southern and eastern shorelines with alluvial deposits. Its Native American name was Okwata ("Wide Water"). In 1699, French explorer Pierre Le Moyne d'Iberville renamed it Pontchartrain after Louis Phélypeaux, comte de Pontchartrain.
Human habitation of the region began at least 3,500 years ago, but increased rapidly with the arrival of Europeans about 300 years ago. The great American naturalist, William Bartram, explored the north shore during a trip west in 1777. In 1852 a railroad was constructed to link New Orleans to the north. Engines turned at Pass Manchac. However, the pilings were burned to the water line in the Civil War. The great cypress swamps of the area were heavily logged in the early 20th century; many have not regrown. The current population in the region is over 1.5 million. There have been many problems with conservation management of the forests and wetlands. The United States Geological Survey is currently monitoring the environmental effects of shoreline erosion, loss of wetlands, pollution from urban areas and agriculture, saltwater intrusion from artificial waterways, dredging, basin subsidence and faulting, storms and sea-level rise, and freshwater diversion from the Mississippi and other rivers. With proper management of this lake and its wetlands, there is great potential to enhance the productivity of wetlands, and to maintain biological diversity to support an ecotourism industry that will diversify the economy.
Conservation and restoration 
Owing to past exploitation, the ecosystems of the lake are under stress. Marshes, for example, are turning to open water, and cypress swamps are being killed by salt water intrusion. There is also good news: Brown Pelicans and Bald Eagles, once scarce, are now a common sight along the shores. A team of experts assembled by The Nature Conservancy assessed the situation in 2004. They identified seven target habitat types that were in particular need of conservation management: Bottomland hardwood forest, Cypress swamp, Relict ridge woodland, Fresh/ intermediate marsh, Brackish/salt Marsh, Lake open water and Littoral submersed aquatic vegetation. The bottomland hardwood forest, and cypress swamp, are suffering from lack of fresh water input and sediment deposition owing to the levees upstream from the lake. In addition, bottomland hardwoods are being invaded by exotic species such as Chinese tallow while freshwater marshes are being invaded by exotic species such as Elephant's-ear. The team also idenfied four key animal species that could indicate the degree to which the system declines or improves. These were Rangia clam (representing lake bottom habitat), Gulf sturgeon and Paddlefish (resperenting fish communities) and the Alligator snapping turtle (one of the largest freshwater turtles in the world, but in decline owing to over- harvesting). The future of the lake depends, in part, on restoring annual spring floods to the wetlands of the lake basin, and controlling urban sprawl on the North shore. Selected species, like the Paddlefish and Alligator snapping turtle, would benefit from reduced harvesting. The lake could change considerably without such conservation planning. A few examples of future change might include: more cypress swamps could convert to anthropogenic marsh or open water, Chinese tallow could displace native forests, and, with a warming climate, mangrove trees could replace brackish marsh. Hence the ecosystems of the lake now, and in the future, depend very much upon some basic decisions about human activities in the vicinity of the lake, and, even more so, human activity upstream along the Mississippi River.
North of Lake Pontchartrain is an area called the North Shore or Northshore or the Northlake area. It is composed of cities such as Mandeville, Covington, Abita Springs, Madisonville, Lacombe, Slidell in Saint Tammany Parish; Ponchatoula, Hammond, and Amite in Tangipahoa Parish; and Franklinton and Bogalusa in Washington Parish. These Northshore parishes form the eastern Florida Parishes. This landscape here is mostly uplands that were once dominated by long leaf pine savannas and interrupted by occasional large rivers. The savannas were maintained by regular fires caused by lightning, and produced the distinctive fauna and flora of this region.
The Southshore areas, instead of being designated by that name, are more likely to be referred to as either "Eastbank" or "Westbank" depending on their position with respect to the general direction of flow of the Mississippi River. Lake Ponchartrain forms the northern boundary of the city of New Orleans, which is coterminous with Orleans Parish, and its two largest suburbs Metairie and Kenner, as well as the northern boundary of Jefferson Parish and Saint Charles Parish and much of the northern and eastern boundaries of Saint John the Baptist Parish.
New Orleans 
New Orleans was established at a Native American portage between the Mississippi River and Lake Pontchartrain. The lake provides numerous recreational activities for people in New Orleans and is also home to the Southern Yacht Club. In the 1920s, the Industrial Canal in the eastern part of the city opened, providing a direct navigable water connection, with locks, between the Mississippi River and the lake. In the same decade, a project dredging new land from the lake shore behind a new concrete floodwall began; this would result in an expansion of the city into the former swamp between Metairie/Gentilly Ridges and the lakefront. The Lake Pontchartrain Causeway was constructed in the 1950s and 1960s, connecting New Orleans (by way of Metairie) with Mandeville and bisecting the lake in a north-northeast line. At 24 miles (39 km), the Causeway is the second-longest bridge over a body of water in the world.
During hurricanes, a storm surge can build up in Lake Pontchartrain. Wind pushes water into the lake from the Gulf of Mexico as a hurricane approaches from the south, and from there it can spill into New Orleans.
A hurricane in September 1947 flooded much of Metairie, Louisiana, much of which is slightly below sea level due to land subsidence after marshland was drained. After the storm, hurricane-protection levees were built along Lake Pontchartrain's south shore to protect New Orleans and nearby communities. A storm surge of 10 feet (3.0 m) from Hurricane Betsy overwhelmed some levees in Eastern New Orleans in 1965, while storm surge funneled in by the Mississippi River – Gulf Outlet Canal and a levee failure flooded most of the Lower 9th Ward. After this the levees encircling the city and outlying parishes were raised to heights of 14 to 23 feet (4.3 to 7.0 m). Due to cost concerns, the levees were built to protect against only a Category 3 hurricane; however, some of the levees initially withstood the Category 5 storm surge of Hurricane Katrina (August 2005), which only slowed to Category 3 winds within hours of landfall (due to a last-minute eyewall replacement cycle).
Experts using computer modeling at Louisiana State University after Hurricane Katrina have concluded that the levees were never topped but rather faulty design, inadequate construction, or some combination of the two were responsible for the flooding of most of New Orleans: some canal walls leaked underneath because the wall foundations were not deep enough in peat-subsoil to withstand the pressure of higher water.
Congress failed to fully fund an upgrade requested during the 1990s by the Army Corps of Engineers, and funding was cut in 2003-04 despite a 2001 study by the Federal Emergency Management Agency warning that a hurricane in New Orleans was one of the country’s three most likely disasters. Raising and reinforcing the levees to resist a Category 5 hurricane might take 25 years to complete. Some estimates place the cost at $25 billion.
Hurricane Katrina 
When Hurricane Katrina reached Category 5 in 2005, some experts predicted that the levee system might fail completely if the storm passed close to the city. Although Katrina weakened to a Category 3 before making landfall on August 29 (with only Category 1-2 strength winds in New Orleans on the weaker side of the eye of the hurricane), the outlying New Orleans East along south Lake Pontchartrain was in the eyewall with winds, preceding the eye, nearly as strong as Bay St. Louis, MS. Canals near Chalmette began leaking at 8 am, and some levees/canals, designed to withstand Category 3 storms, suffered multiple breaks the following day (see Effect of Hurricane Katrina on New Orleans), flooding 80% of the city.
The walls of the Industrial Canal were breached by storm surge via the Mississippi River Gulf Outlet, while the 17th Street Canal and London Avenue Canal experienced catastrophic breaches, even though water levels never topped their flood walls. Louisiana State University experts presented evidence that some of these structures might have had design flaws or faulty construction.
There are indications that the soft earth and peat underlying canal walls may have given way. In the weeks before Katrina, tests of salinity in seepage pools near canals showed them to be lake water, not fresh water from broken mains. The 5.5-mile-long (8.9 km) I-10 Twin Span Bridge heading northeast between New Orleans and Slidell was destroyed. The shorter Fort Pike Bridge crossing the outlet to Lake Borgne remained intact.
Much of the northern sector of the suburban areas of Metairie and Kenner was flooded with up to 2 to 3 feet (0.6 to 0.9 m) of water. In this area, flooding was not the result of levee overtopping, but was due to a decision by the governmental administration of Jefferson Parish to abandon the levee-aligned drainage pumping stations. This resulted in the reverse flow of lake water through the pumping stations into drainage canals which subsequently overflowed, causing extensive flooding of the area between I-10 and the lakefront. When the pump operators were returned to their stations, water was drained out of Metairie and Kenner in less than a day, in some cases, only a few hours.
On September 5, 2005, the Army Corps of Engineers started to fix levee breaches by dropping huge sandbags from Chinook helicopters. The London Avenue Canal and Industrial Canal were blocked at the lake as permanent repairs started. On September 6, the Corps began pumping flood water back into the lake after seven days in the streets of New Orleans. Because it was fouled with dead animals, sewage, heavy metals, petrochemicals, and other dangerous substances, the Army Corps worked with the U.S. Environmental Protection Agency and Louisiana Department of Environmental Quality (LDEQ) to avoid major contamination and eutrophication of the lake.
Aerial photography suggests that 25 billion US gallons (95,000,000 m3) of water covered New Orleans as of September 2, which equals about 2% of Lake Pontchartrain's volume. Due to a lack of electricity, the city was unable to treat the water before pumping it into the lake. It is unclear how long the pollution will persist and what its environmental damage to the lake will be, or the hazards from the mold and contaminated mud remaining in the city.
On September 24, 2005, Hurricane Rita did not breach the temporary repairs in the main part of the city, but the repair on the Industrial Canal wall in the lower 9th ward was breached, allowing about 2 feet (0.61 m) of water back into that neighborhood.
Popular culture 
- The traditional song "On the Banks of the Pontchartrain" has been recorded by such artists as Hank Williams, George Jones, Amos Garrett, D.L. Menard, Blue Mountain (band) and Doug Sahm.
- The Lakes of Pontchartrain, a variation on the above traditional song, was arranged and recorded by Irish singer Paul Brady & Christy Moore, both solo and with Planxty, The Be Good Tanyas, Jim Smoak, The Coronas & The Louisiana Honeydrippers and Deanta.
- Nanci Griffith performs "Banks of the Pontchartrain", a song that she composed, on her album The Last of the True Believers.
- "Pontchartrain" is the title of a song on the album Dreaming Through the Noise by Vienna Teng. The lyrics reference bodies in the lake and lost memories.
- "Pontchartrain" is the title of a song composed and recorded by Jelly Roll Morton.
- The lake is mentioned in a verse of "Heart of the Night," American country rockers Poco's ode to New Orleans, from their album Legend.
- In the Jimmy Buffett song, "Breath In, Breathe Out, Move On" from his album Take the Weather with You, Pontchartrain is mentioned twice in reference to flooding and hurricanes.
- Sonny Landreth's song "Soldier of Fortune" from his album Outward Bound mentions the Pontchartrain.
- George Strait mentions the Pontchartrain several times in his song "Adalida" from his album Lead On.
- The Lost Trailers have a song "Fire on the Pontchartrain" from their album Welcome to the Woods.
- Lake Pontchartrain is mentioned in the song "Long Overdue for a Miracle" in the musical Whistle Down the Wind.
- Lake Pontchartrain is briefly mentioned in the song "Feels Like Rain", by John Hiatt from his album Slow Turning, and by Buddy Guy from his album Feels Like Rain
- Lake Pontchartrain is mentioned in the Lucinda Williams songs "Lake Charles" from her album Car Wheels on a Gravel Road, and "Crescent City" from Lucinda Williams.
- "Lake Pontchartrain" is a song in the album A Good Life from Joe Grushecky in 2006.
- "Lake Pontchartrain" is the title of a song by the band Ludo, from their album You're Awful, I Love You. The song describes a man who finds himself by the lake with two of his friends,when his friends eat the local crawfish they are drawn to the lake where they are devoured by the lake itself. However, this is actually an alibi for his murder of said friends.
- Sheryl Crow's song "Love Is Free" from her album Detours mentions the Pontchartrain.
- Aaron Watson mentions Lake Pontchartrain in his song "Heaven Help the Heart" from his album Shutupanddance.
- Blue Mountain (band) mentions Lake Pontchartrain in their song "Lakeside" from their album Tales of a Traveler.
- The song "Broke Down" by Slaid Cleaves from his album Broke Down mentions Lake Pontchartrain in the second verse.
- The song "Death and Hell" from the album The Road Goes on Forever by the country supergroup The Highwaymen, featuring Johnny Cash and Waylon Jennings, mentions the Pontchartrain.
- Scottish Singer/Songwriter Roddy Frame refers to Pontchartrain in his song "Bigger Brighter Better" from his album "The North Star"
- Lake Pontchartrain and New Orleans is the setting of the song "Heart Of The Night" by Paul Cotton from the 1978 album Legend by the country rock band Poco.
- "Dorraine of Ponchartrain" is a song from the 1960 Johnny Cash concept album Ride This Train.
- Catie Curtis mentions Lake Ponchartrain in the extended final chorus of her song "People Look Around" in the album "Long Night Moon."
- Emmylou Harris mentions Lake Pontchartrain in her song "New Orleans" on the album "Hard Bargain".
- Mary Chapin Carpenter song "Houston" from her 2007 album "The Calling" mentions Lake Pontchartrain ("I stood up on the banks / And looked out over Pontchartrain").
- Levon Helm mentions Lake Pontchartrain in the chorus of the song "Hurricane" on his "American Son" album.
In other media:
- In the 2004 video game James Bond 007: Everything or Nothing, one mission involves a chase across the lake on the Lake Pontchartrain Causeway.
- The lake is also featured in the 1993 PC game Gabriel Knight: Sins of the Fathers.
- It is featured in the 2003 film The Haunted Mansion, to identify the area's location.
- Lake Pontchartrain is mentioned repeatedly in the novel Heart Shaped Box by Joe Hill.
- Blanche DuBois and Harold Mitchell visit Pontchartrain Beach amusement park at the beginning of Scene Six in Tennessee Williams' A Streetcar Named Desire.
- Cate Blanchett and Brad Pitt see the sunrise on the shore of Lake Pontchartrain in The Curious Case of Benjamin Button.
- The lake used in the 2011 thriller Shark Night 3D is based on Lake Pontchartrain.
- The lake is mentioned in episode three season one of Supernatural as a lake that was haunted and had supposed sightings of a lake monster.
Notable deaths 
- Eastern Air Lines Flight 304 crashed into the lake on February 25, 1964, resulting in the deaths of 51 passengers and 7 crew. Very little of the plane or passengers was ever recovered.
- On September 15, 1978, six-year-old Benjamin Daly died when a private plane his parents had chartered crashed into the lake. His parents survived but Benjamin and the pilot perished.
- In 1986, a decomposing woman's body was found by two fishermen. The cause of death was homicide by asphyxia. She was not identified and no leads were ever identified in the case.
- New England Patriots defensive end, New Orleans native and former LSU star Marquise Hill was found dead in Lake Pontchartrain on May 28, 2007.
- A U.S. Navy T-34 training plane crashed into the lake on January 23, 2010, after a routine training mission. The instructor, Lt. Clinton Wermers, is missing and presumed dead. The student pilot was rescued about two hours after the crash.
See also 
- Lake Pontchartrain Causeway
- Bonnet Carré Spillway
- Tammany Trace Rail Trail
- Louisiana's 1st congressional district
- Keddy, P.A., D. Campbell, T. McFalls, G. Shaffer, R. Moreau, C. Dranguet, and R. Heleniak. 2007. The wetlands of lakes Pontchartrain and Maurepas: past, present and future. Environmental Reviews 15: 1-35.
- Louisiana Department of Culture, Recreation and Tourism. "Lake Pontchartrain Historical Marker".
- Keddy, P.A., D. Campbell, T. McFalls, G. Shaffer, R. Moreau, C. Dranguet, and R. Heleniak. 2007. The wetlands of lakes Pontchartrain and Maurepas: past, present and future. Environmental Reviews 15: 1- 35.
- Keddy, P.A., D. Campbell, T. McFalls, G. Shaffer, R. Moreau, C. Dranguet, and R. Heleniak. 2007. The wetlands of lakes Pontchartrain and Maurepas: past, present and future. Environmental Reviews 15: 1- 35. Table 2.
- "Environmental Atlas of the Lake Pontchartrain Basin". USGS Coastal and Marine Geology Program. May 14, 2002. Retrieved 2006-06-15.
- Perrin, J.M. 2000. Home Town Ponchatoula. A Community History of Ponchatoula, Louisiana. Self-published. Ponchatoula, Louisiana.
- Norgress, R. E. (1947). The history of the cypress lumber industry in Louisiana. Louisiana Historical Quarterly 30: 979–1059.
- Keddy, P.A. 2008. Water, Earth, Fire: Louisiana’s Natural Heritage. Xlibris, Philadelphia. 229 p.
- Houck, O. 2006. Can we save New Orleans? Tulane Environmental Law Journal 19: 1–68.
- Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p.
- With "The Lake Pontchartrain Basin: Louisiana's Troubled Urban Estuary". U.S. Geological Survey. November 3, 1995. Retrieved 2006-06-15.
- Maygarden, D. and others. 2004. Conservation Area Plan for the Lake Pontchartrain Estuary. The Nature Conservancy, LA.
- Keddy, P.A., D. Campbell, T. McFalls, G. Shaffer, R. Moreau, C. Dranguet, and R. Heleniak. 2007. The wetlands of lakes Pontchartrain and Maurepas: past, present and future. Environmental Reviews 15: 1- 35. Fig. 21
- See, e.g., the article on the Westbank Expressway. In actuality in this realm of the Mississippi River's course, by compass directions the "Westbank" is really the north bank and the "Eastbank" the south bank. Cf. Uptown New Orleans and Downtown New Orleans.
- Grunwall, Michael; Glasser, Susan B. (September 21, 2005). "Experts Say Faulty Levees Caused Much of Flooding". washingtonpost.com. Retrieved 2006-06-15.
- Blumenthal, Sidney (August 31, 2005). "No one can say they didn't see it coming". Salon.com. Retrieved 2006-06-15.
- Handwerk, Brian (September 2, 2005). "New Orleans Levees Not Built for Worst Case Events". National Geographic News.
- Grunwald, Michael; Glasser, Susan B. (September 21, 2005). "Experts Say Faulty Levees Caused Much of Flooding". washintonpost.com. Retrieved 2006-06-15.
- Broussard says he didn't send pump operators away - Kenner Bulletin - NOLA.com.
- USACE (September 2005). "Quick, coordinated efforts reduce environmental impact on Lake Pontchartrain". usace.army.mil. Archived from the original on May 13, 2007. Retrieved 2007-07-03.(Dead link)
- "Body Discovered--Two Decade Mystery Begins". Sex-offenders.info. Retrieved 27 January 2010.
- Simpson, April; Levenson, Michael (May 29, 2007). "Patriot Hill is found dead". boston.com. Retrieved 27 January 2010.
- "Navy pilot presumed dead after crash in Lake Pontchartrain". cnn.com. January 25, 2010. Retrieved 25 January 2010.
Further reading 
- Lake Pontchartrain, 2007, ISBN 978-0-7385-4392-5
|Wikimedia Commons has media related to: Lake Pontchartrain|
- Lake Pontchartrain Basin Foundation
- United States Geological Survey Lake Pontchartrain Fact Sheet
- Real-time water data for Lake Pontchartrain
- New Orleans history of the lake
- Lake Pontchartrain Basin Maritime Museum
- USGS Environmental Atlas of Lake Pontchartrain
- New Orleans District Water Management
- Washington Post article alleging levee faults, 21 September 2005
- National Geographic article about the levees, 2 September 2005
- Salon article about disaster predictions, 31 August 2005
- U.S. Geological Survey article about the Lake Pontchartrain Basin, 3 November 1995
- BBC article about environmental effects on the lake after the flooding of New Orleans, 8 September 2005