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.

• 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.