Coastal Louisiana is on an unsustainable trajectory of ongoing conversion of coastal land to open water and increasing hurricane flood risk. The causes of the ongoing land loss are varied and include natural and human-caused land subsidence, rising sea level, and the loss of nourishing sediment from Mississippi River flows that is now deposited deep in the Gulf of Mexico. Since the 1930s, 1,800 square miles have been lost (Couvillion et al., 2011). Without major investments in coastal restoration, the Coastal Protection and Restoration Authority of Louisiana (CPRA) estimates that an additional 800 square miles of coastal land could be...

The Planning Tool identifies alternatives (groups of projects) over a 50-year planning horizon using an optimization model. These alternatives (1) minimize coast-wide risk to economic assets through risk-reduction projects and (2) maximize coast-wide land building through restoration projects. Risk-reduction projects include structural features, such as levees and flood-walls, and nonstructural programs that reduce flood damage to residential and commercial structures through elevating, flood-proofing, or removing the structures. Restoration projects include bank stabilization, barrier island restoration, channel realignment, sediment diversion, hydrologic restoration, marsh creation, oyster barrier reef, ridge restoration, and shoreline protection. (See CPRA, 2012c, Appendix C, for details on all...

This chapter describes the five analytic procedures required to develop and compare the alternatives identified in the Master Plan. CPRA, its consulting team, and the predictive modeling teams executed the first two procedures—characterization of projects and modeling project effects. Outputs from these procedures were then provided to the Planning Tool team along with input data on restoration and risk-reduction projects. In the third and fourth procedures—comparison of individual projects and formulation of alternatives—the Planning Tool was used to inform the development of the Master Plan. The last—integrated evaluation of alternatives—is made up of additional analyses...

CPRA used the Planning Tool and associated analyses to support the development of the draft Master Plan (released in January 2012) and the Master Plan (published in March 2012) (CPRA, 2012a, 2012c). Figure 4.1 lists the key analytic steps and outcomes for these analyses. CPRA and RAND shared many of these results with Louisiana stakeholders and decision-makers during the fall and winter of 2011–2012 using the Planning Tool’s interactive Tableau interface (see “Tableau Results Visualizer” in Chapter Two). The Planning Tool analysis was extensive, with significant information generated for each project and alternative. This chapter offers only a snapshot...

The Planning Tool played a critical role in the development of CPRA’s Master Plan. It provided a structured, analytic framework for comparing different risk-reduction and restoration projects, formulating many different alternatives, each representing one possible comprehensive approach to solving the coast risk and land-loss problems, and providing information to support the deliberation needed to formulate a single 50-year plan. The resulting 50-year Master Plan received strong public support and passed the Louisiana legislature unanimously in May 2012.

To accommodate the data and modeling available, the Planning Tool by necessity included some significant simplifying assumptions to provide useful quantitative information to...