Study Area

Tangipahoa Parish is in Southeast Louisiana and extends from Lake Maurepas and Lake Pontchartrain on the south to the border of Mississippi on the north.  Major communities in the study area include Ponchatoula, Hammond, Robert, Kentwood, and Tickfaw.

The study area supports a broad range of industries including distribution centers, truck farming, dairy farming, and the forestry industry. The study area also includes critical hurricane evacuation routes, including Interstates 12 and 55, as well as the Hammond Northshore Regional Airport and the Hammond Amtrak, which provide transportation to neighboring parishes and the New Orleans Metropolitan Area. Urban development is occurring in the study area and is expected to continue due to its proximity to the New Orleans metropolitan area and the I-12 and I-55 transportation corridors. Development is expected to convert agricultural and forested land to residential and commercial uses. 

The communities within Tangipahoa Parish, Louisiana are continually impacted by widespread riverine flooding from heavy rainfall events often associated with hurricanes and tropical storms. Flooding poses a significant risk to life safety and causes damage to residential and commercial structures.  The study area includes residential and commercial structures that have experienced damage and economic impacts caused by repeated flooding events.  The scope also includes analysis of impacts caused by coastal flooding, such as storm surge and waves, where there is overlapping risk of riverine and coastal flooding.  There is a small area in the southernmost portion of the Parish where this occurs.  

 

Project Description

The overall goal of the study is to identify and potentially recommend actions to reduce flood risk to public safety and human life and reduce economic damages caused by riverine flooding within Tangipahoa Parish, Louisiana, through approximately 2083 (the 50-year period of analysis).  

The focus of the study is on riverine flooding occurring within Tangipahoa Parish, which is approximately 823 square miles and located in southeastern Louisiana.  Tangipahoa Parish is home to over 137,000 residents and 2,500 businesses. The Parish extends from the Mississippi State line in the north to Lake Pontchartrain and Lake Maurepas to the south and extends from the eastern boundary with Washington and St. Tammany Parishes and St. Helena and Livingston Parish boundaries in the west. The most populated areas within the Parish include the cities of Hammond and Ponchatoula and the towns of Amite City (Parish seat), Independence, Kentwood, and Roseland.  The parish is located at the crossroads of interstates I-55 and I-12 which serves as a national transportation corridor and evacuation route for Metropolitan New Orleans, LA. 

The Tangipahoa River is a major waterway that flows through the central and eastern portions of the Parish, from the north to south, and is part of the Louisiana Natural and Scenic Rivers System.  The Natalbany and Little Natalbany Rivers flow along the western boundary of the Parish flowing from the north to south.  Ponchatoula Creek, Selser’s Creek, and the Big Branch drain the south-central part of the Parish and flow from the north to south. Riverine-caused flooding tends to be more prevalent along major river systems within the Parish and in the southern portions of the Parish due to the elevation and proximity to Lake Pontchartrain. The hydrology is complex, and communities experience repeated damages from flooding.

Impacts

The area is continually impacted by widespread flooding from tropical storms and hurricanes and had disaster declarations for Hurricane Ida in 2021 as well as Hurricane Laura, Tropical Storm Cristobal, and Tropical Storms Laura and Marco in 2020.  The study area also saw historic impacts in March and August of 2016 which caused major damages to 12,700 homes and 1,500 businesses and impacted approximately 17,000 workers in the parish.

Anticipated Future Conditions

Increased flood risk in the study area is anticipated due to repeated heavy rainfall storm events, and changes in hydrology from development activities. This will result in higher and more frequent storm damages and higher average annual damages. These impacts would be exacerbated due to heavy rainfall coupled with increases in relative sea level.

Current Project Status

Since the previous public meetings, the study team has been working with and incorporating input from the non-federal sponsor, Louisiana Coastal Protection and Restoration Authority, stakeholders, and from the public to combine measures into a range of alternatives to address the flood-related project objectives.  The team evaluated over 40 measures that were combined to form potential structural alternatives (strategies) aimed at reducing risk of flood damages within the study area. In addition, several nonstructural measures were combined to develop a range of potential nonstructural alternatives to address risk of flooding in the study area. In total, 19 alternatives were developed for consideration (14 structural, 4 nonstructural, and the no action alternative). The analysis of alternatives, assessment of conditions within the Parish, and evaluation of potential impacts led to the development of a final array of alternatives.

The development and evaluation of these potential alternatives are provided in the draft feasibility report.

When the final report is complete it will be publicly shared, and there will be another open comment period for approximately 30 days. Comments will again be evaluated and incorporated as applicable into the final report.

An interdisciplinary team is working to identify a variety of measures, both structural and nonstructural, that can be evaluated for their ability to reduce flood risk within Tangipahoa Parish. The list of measures identified for consideration based on stakeholder and public input to date included the following:

 Measures that are not effective at addressing project problems are removed from consideration over time and the list is refined as more information becomes available and as various analyses of conditions (ex. Hydrologic and hydraulic, economic, environmental, etc.) are conducted. The team will evaluate a range of alternatives which consist of measures or groups of measures that can be implemented together to potentially address flood risk problems in the study area.

Flood-related Problems to be Addressed by Study

  • Damage to structures (both residential and commercial) resulting from riverine flooding

  • Risk to human life resulting from riverine flood depths and velocities, as well as impacts to critical infrastructure such as fire and rescue services.

  • Risk to national transportation corridor and Evacuation Routes (I-55 / I-12 / 190 / LA-445), as well as damage to government facilities, schools, fire stations, wastewater treatment plants

  • Increased risk to historically significant structures

  • Sea level rise may increase flood frequency in the future. 

  • Increased development has led to increased flooding

 

The Planning Constraints are:

  • To the maximum extent practicable, avoid promoting development within the floodplain (in accordance with E.O. 11988), which contributes to increased life safety risk.
  • Proposed projects must meet minimum flow (800 cubic feet per second for a 10 percent chance flood) and drainage area (1.5 square miles) requirements for inclusion in the plan formulation (ER 1165-2-21).

 


Study opportunities related to identified flood-risk problems in Tangipahoa Parish include:

  • Public Safety - Enhance public education and awareness to flood risk.
  • Community Resilience – Improve the communities’ ability to prepare, mitigate, and recover from flood events
  • Recreation - Incorporate public recreational features incidental to proposed flood risk management alternatives.
  • Ecosystem – Protect function of the ecosystem through development of flood risk management measures that are nature based.

The Planning Objectives are:

  • Reduce the risk to public safety associated with riverine flood impacts to residential and nonresidential structures, evacuation routes, and access to critical infrastructure. 
  • Reduce economic loss due to flood damage to structures and infrastructure (i.e., businesses, residential, commercial, and public structures) from riverine flooding.
  • Reduce economic impacts, due to interruption of evacuation routes and a national transportation corridor, e.g., the I-12 and I-55, during flood events. 
  • Increase community resiliency which is the sustained ability of a community to use available resources, before, during, and after flood events.
  • In conjunction with reducing flood risk and economic flood damages in the study area overall, act to benefit underserved communities and avoid disproportionate impacts to disadvantaged communities.

Floodproofing: Wet vs. Dry

Why consider floodproofing?

Latest News on Tangipahoa

Corps of Engineers schedules public meetings to present flood-risk management report for Tangipahoa Parish, Louisiana Feasibility Study

The U.S. Army Corps of Engineers, New Orleans District have scheduled three public meetings to present information and gather public comments for the tentatively selected plan detailed in the Tangipahoa Parish, Louisiana Flood Risk Management Study Draft Integrated Feasibility Report and Environmental Assessment.
Published: 8/14/2024

Corps of Engineers releases Tangipahoa Parish, Louisiana Flood Risk Management Study draft integrated feasibility report and environmental assessment for public review

The U.S. Army Corps of Engineers released the Tangipahoa Parish, Louisiana Flood Risk Management Study Draft Integrated Feasibility Report and Environmental Assessment for a 45-day public review and comment period starting Aug. 9, 2024.
Published: 8/9/2024

Tangipahoa Parish, Louisiana Feasibility Study public meetings scheduled

NEW ORLEANS – The U.S. Army Corps of Engineers, New Orleans District have scheduled two public scoping meetings to present information and gather public input for the Tangipahoa Parish, Louisiana Feasibility Study.
Published: 8/30/2023

Tangipahoa Parish, Louisiana Feasibility Study open houses scheduled

The U.S. Army Corps of Engineers, New Orleans District scheduled two pre-scoping open houses to gather public input for the Tangipahoa Parish, Louisiana Feasibility Study.
Published: 2/7/2023