The greater New Orleans Hurricane & Storm Damage Risk Reduction System (HSDRRS) is an infrastructure system in southern Louisiana which seeks to provide the greater New Orleans area a 100-year level of risk reduction, meaning reduced risk from a storm surge that has a 1% chance of occurring or being exceeded in any given year. In 2019, the Army Corps of Engineers announced that due to an increased rate of sea level rise and continued sinking of soil the levee system would no longer offer original planned levels of protection as early as the year 2023. [1]
While a protection system existed prior to 2005, following Hurricane Katrina, Congress authorized and funded the construction of the 100-year level risk reduction system, known as the Hurricane and Storm Damage Risk Reduction System (HSDRRS). The HSDRRS includes five parishes (Orleans, Jefferson, St. Bernard, St. Charles, and Plaquemines) and consists of 350 miles of levees and floodwalls; 73 non-Federal pumping stations; 3 canal closure structures with pumps; and 4 gated outlets. [2]
The Greater New Orleans HSDRRS is engineered to the 100-year level of risk reduction against tropical events and related rainfall and storm surges. The $14 billion system includes the construction or improvement of 133 miles of perimeter risk reduction features, such as levees, floodwalls, floodgates and pump stations. HSDRRS was designed for a 50-year project life and the design accounted for sea level rise, subsidence and increased storm frequency throughout that time frame. Construction of the system also included resiliency features, such as the armoring of the backside of levees and floodwalls to prevent scour in the event of wave overtopping. [3]
The Corps also supports the multiple lines of defense strategy for reducing risk, which includes the restoration of Louisiana's coastal areas. Coastal habitats provide an important buffer between open water and structural protection like the HSDRRS.
The HSDRRS construction project is planned and executed by the U.S. Army Corps of Engineers' New Orleans District of the Mississippi Valley Division. Dutch experts of engineering firms such as Arcadis, Royal Haskoning/DHV, Fugro and HKV Consultants were closely involved in the planning, designing and implementation. [4]
Upon completion, the Corps of Engineers plans to give responsibility to local authorities for operations and maintenance of the system. [5]
The IHNC Surge Barrier project connects the perimeter system in New Orleans East to the perimeter system in St. Bernard Parish. The Surge Barrier consists of a 150 ft. sector gate and 150 ft. barge gate along the Gulf Intracoastal Waterway West. It boasts a 1.8 miles concrete wall to protect New Orleans in the case of a flood. It is the largest civil works project in Louisiana history. All major construction was completed in June, 2013.
The total construction value is estimated at $1.1 billion. [6]
The Mississippi River–Gulf Outlet Canal is a 76 mi (122 km) channel constructed by the United States Army Corps of Engineers at the direction of Congress in the mid-20th century that provided a shorter route between the Gulf of Mexico and New Orleans' inner harbor Industrial Canal via the Intracoastal Waterway. In 2005, the MRGO channeled Hurricane Katrina's storm surge into the heart of Greater New Orleans, contributing significantly to the subsequent multiple engineering failures experienced by the region's hurricane protection network. In the aftermath the channel was closed. A permanent storm surge barrier was constructed in the MRGO in 2009, and the channel has been closed to maritime shipping.
Hurricane preparedness in New Orleans has been an issue since the city's early settlement because of its location.
From 1890 through 2006, the Orleans Levee Board (OLB) was the body of commissioners that oversaw the Orleans Levee District (OLD) which supervised the levee and floodwall system in Orleans Parish, Louisiana The role of the OLB has changed over time. Prior to Hurricane Betsy in 1965, the OLB developed land and sold it to raise money to build and improve flood protection levees. After Betsy, Congress passed the Flood Control Act of 1965 which directed the Army Corps of Engineers to design and build the hurricane flood protection system enveloping New Orleans. Owing to the 1965 legislation, the OLB's duties were now limited to collecting the 30% cost share for project design and construction, and to maintaining and operating completed flood protection structures.
The Industrial Canal is a 5.5 mile (9 km) waterway in New Orleans, Louisiana, United States. The waterway's proper name, as used by the U.S. Army Corps of Engineers and on NOAA nautical charts, is Inner Harbor Navigation Canal (IHNC). The more common "Industrial Canal" name is used locally, both by commercial mariners and by landside residents.
The 17th Street Canal is the largest and most important drainage canal in the city of New Orleans. Operating with Pump Station 6, it moves water into Lake Pontchartrain. The canal, along with the Orleans Canal and the London Avenue Canal, form the New Orleans Outfall Canals. The 17th Street Canal forms a significant portion of the boundary between the city of New Orleans and Metairie, Louisiana. The canal has also been known as the Metairie Outlet Canal and the Upperline Canal.
The London Avenue Canal is a drainage canal in New Orleans, Louisiana, used for pumping rain water into Lake Pontchartrain. The canal runs through the 7th Ward of New Orleans from the Gentilly area to the Lakefront. It is one of the three main drainage canals responsible for draining rainwater from the main basin of New Orleans. The London Avenue Canal's flood walls built atop earthen levees breached on both sides during Hurricane Katrina in 2005.
Though Hurricane Katrina did not deal the city of New Orleans a direct hit on August 29, 2005, the associated storm surge precipitated catastrophic failures of the levees and flood walls. The Mississippi River Gulf Outlet ("MR-GO") breached its levees in approximately 15 places. The major levee breaches in the city include the 17th Street Canal levee, the London Avenue Canal, and the wide, navigable Industrial Canal, which left approximately 80% of the city flooded.
On Monday, August 29, 2005, there were over 50 failures of the levees and flood walls protecting New Orleans, Louisiana, and its suburbs following passage of Hurricane Katrina. The failures caused flooding in 80% of New Orleans and all of St. Bernard Parish. In New Orleans alone, 134,000 housing units — 70% of all occupied units — suffered damage from Hurricane Katrina and the subsequent flooding.
A flood barrier, surge barrier or storm surge barrier is a specific type of floodgate, designed to prevent a storm surge or spring tide from flooding the protected area behind the barrier. A surge barrier is almost always part of a larger flood protection system consisting of floodwalls, levees, and other constructions and natural geographical features. Flood barrier may also refer to barriers placed around or at individual buildings to keep floodwaters from entering the buildings.
Drainage in New Orleans, Louisiana, has been a major concern since the founding of the city in the early 18th century, remaining an important factor in the history of New Orleans today. The central portion of metropolitan New Orleans is fairly unusual in that it is almost completely surrounded by water: Lake Pontchartrain to the north, Lake Borgne to the east, wetlands to the east and west, and the Mississippi River to the south. Half of the land area between these bodies of water is at or below sea level, and no longer has a natural outlet for flowing surface water. As such, virtually all rainfall occurring within this area must be removed through either evapotranspiration or pumping. Thus, flood threats to metropolitan New Orleans include the Mississippi River, Lake Pontchartrain, canals throughout the city, and natural rainfall. Artificial levees have been built to keep out rising river and lake waters but have had the negative effect of keeping rainfall in, and have failed on numerous occasions.
The Orleans Canal is a drainage canal in New Orleans, Louisiana. The canal, along with the 17th Street Canal and the London Avenue Canal, form the New Orleans Outfall Canals. The current version of the canal is about 2 km long, running along the up-river side of City Park, through the Lakeview and Lakeshore neighborhood, and into Lake Pontchartrain. It is part of the system used to pump rain water out of the streets of the city into the Lake. The Canal has also been known as the Orleans Avenue Canal, the Orleans Outfall Canal, the Orleans Tail Race, and early on, the Girod Canal.
The Bonnet Carré Spillway is a flood control operation in the Lower Mississippi Valley. Located in St. Charles Parish, Louisiana, about 12 miles (19 km) west of New Orleans, it allows floodwaters from the Mississippi River to flow into Lake Pontchartrain and thence into the Gulf of Mexico. The spillway was constructed between 1929 and 1931, following the Great Mississippi Flood of 1927, and has been designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers.
The United States Army Corps of Engineers is involved with a wide spectrum of public works projects: environmental protection, water supply, recreation, flood damage and reduction, beach nourishment, homeland security, military construction, and support to other Governmental agencies. Through 19 Flood Control Acts since 1917, Congress has authorized the Corps of Engineers to be involved with flood protection and damage reduction in almost every state of the union.
The United States Army Corps of Engineers is involved with a wide spectrum of public works projects: environmental protection, water supply, recreation, flood damage and reduction, beach nourishment, homeland security, military construction, and support to other Governmental agencies. In nineteen (19) different Flood Control Acts since 1917, the United States Congress has authorized the corps to design and build flood protection projects and one risk reduction system in the Greater New Orleans area and throughout the nation.
The Inner Harbor Navigation Canal Lake Borgne Surge Barrier is a storm surge barrier constructed near the confluence of and across the Gulf Intracoastal Waterway (GIWW) and the Mississippi River Gulf Outlet (MRGO) near New Orleans. The barrier runs generally north-south from a point just east of Michoud Canal on the north bank of the GIWW and just south of the existing Bayou Bienvenue flood control structure.
The Gulf Intracoastal Waterway West Closure Complex is a part of the New Orleans Drainage System; it consists of a navigable floodgate, a pumping station, flood walls, sluice gates, foreshore protection, and an earthen levee. The complex was designed to reduce risk for residences and businesses in the project area from a storm surge associated with a tropical event, with an intensity that has a one percent chance of occurring in any given year. This project was operated for the first time on August 29, 2012, in response to Hurricane Isaac.
The Inner Harbor Navigation Canal (IHNC) Seabrook Floodgate Structure is a flood barrier in the Industrial Canal in New Orleans, Louisiana. The floodgate is designed to protect the Industrial Canal and the surrounding areas from a storm surge from Lake Pontchartrain. It consists of two 50-foot (15 m) wide vertical lift gates and a 95-foot (29 m) wide sector gate.
There are three outfall canals in New Orleans, Louisiana – the 17th Street, Orleans Avenue and London Avenue canals. These canals are a critical element of New Orleans’ flood control system, serving as drainage conduits for much of the city. There are 13 miles (21 km) of levees and floodwalls that line the sides of the canals. The 17th Street Canal is the largest and most important drainage canal and is capable of conveying more water than the Orleans Avenue and London Avenue Canals combined.
The effects of Hurricane Isaac in Louisiana were more severe than anywhere in the storm's path, and included $611.8615 million in damages and five total deaths. Forming from a tropical wave in the central Atlantic, Isaac traversed across many of the Lesser and Greater Antilles, before reaching peak intensity with winds of 80 mph (130 km/h) on August 28, 2012 while in the Gulf of Mexico. Nearing the coast of Louisiana, the Category 1 hurricane slowly moved towards the west, making two landfalls in the state with little change of intensity prior to moving inland for a final time. The hurricane weakened and later dissipated on September 1 while over Missouri. Before landfall, Governor Bobby Jindal declared a state of emergency to the state, as well as ordering the mandatory evacuation of 60,000 residents in low-lying areas of Louisiana along the Tangipahoa River in Tangipahoa Parish.
The New York Harbor Storm-Surge Barrier is a proposed flood barrier system to protect the New York-New Jersey Harbor Estuary from storm surges. The proposed system would consist of one barrier located across the mouth of Lower New York Bay, possibly between Sandy Hook (N.J.) and Rockaway (N.Y.), and a second on the upper East River to provide a ring of protection to most of the bi-state region. Through extensive use of floodgates, both barriers would have largely open cross-sections during normal conditions to minimize environmental impacts on the estuary and port operations.