Types of Projects

We developed a list of approximately 400 projects for evaluation in the 2012 Master Plan.  Included in this project list are restoration projects, structural risk reduction projects (e.g. levees), and non-structural risk reduction projects (e.g. elevating homes).

Restoration Projects

The 248 restoration projects on our list can be grouped into the following categories:

Bank Stabilization
Onshore placement of earthen fill and vegetative plantings designed to reduce wave energies and maintain shorelines in open bays, lakes, and bayous. Bank Stabilization projects include work on navigation channels. For the purposes of this plan, we assumed that funding of these projects is the sole responsibility of the federal government.
Barrier Island/Headland Restoration
Creation and restoration of dune, beach, and back barrier marsh to restore or augment Louisiana’s offshore barrier islands and headlands.
Hydrologic Restoration
Project features that restore natural hydrologic patterns either by conveying fresh water to areas that have been cut off by man-made features or by preventing the intrusion of salt water into fresh areas through man-made channels and eroded wetlands.


Marsh Creation
Creation of new wetlands in open water areas through sediment dredging and placement. Most projects involve pipeline conveyance of sediment.
Sediment Diversion
Use of channels and/or structures to divert sediment and fresh water from the Mississippi and Atchafalaya Rivers into adjacent basins.

Channel Realignment
Channels and/or structures that divert all river water and sediment in the Mississippi and Atchafalaya Rivers into adjacent basins. Projects would include the dredging of a new navigation channel.

Oyster Barrier Reefs
Establishment of bioengineered oyster reefs to improve oyster propagation and serve as breakwaters to attenuate wave energies.

Ridge Restoration
Re-establishment of historic ridges in basins through local dredging, sediment placement, and vegetative plantings to restore natural ridge functions.

Shoreline Protection
Nearshore rock breakwaters to reduce wave energies on shorelines in open bays, lakes, sounds, and bayous. Shoreline protection projects also include work on navigation channels. For the purposes of this plan, we assumed that funding of these projects is the sole responsibility of the federal government.

   

 

Protection Projects: Structural

Structural risk reduction projects reduce flood risk in coastal communities by acting as physical barriers against storm surge. We viewed protection through the lens of reducing communities’ expected flooding risk to either the 50 year, 100 year, or 500 year level. To this end, the 33 structural projects evaluated in the 2012 Coastal Master Plan include one or more of the following basic components:

Earthen Levee
The principal component of structural projects is the earthen levee. These structures consist of pyramidal banks of compacted earth that provide a barrier against storm surge for coastal communities and other assets. Levees can either be linear in shape or ringed. Ring levees form a closed risk reduction system that encircles a protected area (referred to as a polder). Linear levees create a closed system by tying into other linear levees or by extending inland to high ground.		  
Concrete Wall
These are typically located at points along an earthen levee that have a high potential for erosion or insufficient space for the wide slopes of an earthen levee. Concrete walls were specified at junctions with water crossings, railroads, and major roadways (i.e., interstates and state highways).		  
Floodgates
Floodgates are needed where levees or concrete walls cross a road or railroad or where they intersect waterways. Floodgates were established for each of these crossings for the structural projects in the master plan.


Pumps
Pumps are needed in enclosed risk reduction systems to allow water that enters a polder to be pumped out. Pumps were included as features of most of our protection measures.		  

Protection Projects: Nonstructural

Nonstructural projects raise homes’ elevations and floodproof homes and businesses to reduce storm related flood risks. Programs such as land use planning, upgrades to building codes, and public education are also a key part of nonstructural efforts.

Many of Louisiana’s coastal parishes have already begun to use nonstructural measures to reduce flood risk in recent years. In fact, elevating homes has been a necessity in our state’s marsh dwelling communities for generations. However, there was no comprehensive nonstructural program for us to reference in our analysis. We wanted to fully integrate nonstructural projects into the 2012 Coastal Master Plan and evaluate as many risk reduction project options as possible. So we developed 116 conceptual nonstructural projects for all inhabited areas along the coast. We evaluated these projects along with structural projects when we considered how to reduce flooding risk from 50 year, 100 year, and 500 year storm surge events.

Elevation                                                                                             This option involves raising residential structures so that their lowest floors are higher than projected flood depths. This measure was considered for areas with a projected flood depth of between 3 and 18 feet.  
Floodproofing
This option refits structures so they can be resistant to flood damages. Residential and commercial floodproofing was considered for areas with projected flood depths of 3 feet or less.		  
Voluntary Acquisition
We considered this option in areas where projected flood depths make elevation or floodproofing infeasible and where residential structures would need to be elevated higher than 18 feet. Our initial estimates were that only a small percent of the total nonstructural program would need this option. We will refine this aspect of the program in close partnership with local communities. A community may wish to move as a group to preserve important cultural ties. Other communities may have different needs. Working closely with affected citizens will help us fine tune this program appropriately.