Managing the Mississippi River’s Sediment, Nutrients, and Fresh Water July 13, 2011

Why? The human need to reduce variability in dynamic systems… to support well intended activities such as flood control, navigation, coastal and economic development, subsurface fluid extraction, agriculture, fisheries production, and others

History Early settlementIndividual agricultural levees 1830’s Navigation channel imp. Post Civil WarOrganized levee districts ft channel at South Pass 1879Mississippi River Commission formed 1917Flood Cont Act – levees from IL to LA 1927Great flood 1928Flood Control Act – MR&T John McPhee, The Control of Nature: "This nation has a large and powerful adversary. Our opponent could cause the United States to lose nearly all her seaborne commerce, to lose her standing as first among trading nations.... We are fighting Mother Nature.... It's a battle we have to fight day by day, year by year, the health of our economy depends on the victory."

Crisis Unforeseen? When discussing the Mississippi River Commission 1894 report of survey on the delta to account for the sinking land it was noted: “The conditions are very different now from those existing prior to the existence of levees. There are at present no annual accretions of sedimentary matters from the periodical overflows of the river. These accretions formerly were a little more than equal to the annual subsidence of the lands…”

History Flood Control Act of 1965 Caernarvon Freshwater Diversion Davis Pond Freshwater Diversion CWPPRA 1990 Multiple small scale projects LCA 2004/WRDA proposed diversions Near-term critical

6 Reconnecting the River

7 River Management: Then Project specific Project area effects Project resource allocation Funding Best available science and engineering

Crisis Continued

Goals Vision Something to achieve Better Science Systems approach to management: Navigation, Flood protection, Ecosystem sustainability National Priority Ecosystem sustainability = Navigation, Flood Control

Vision Louisiana’s Comprehensive Master Plan for a Sustainable Coast : 2012 update Vision Decision Criteria, Constraints, and Uncertainties Comprehensive Project-effects Models Prioritization Tool Prioritized Project Portfolios Expected Outcomes Adaptive Management and Implementation Plan Long–term Funding Scenarios Comprehensive systems approach What do we want to achieve? How do we get there? – Projects Under what circumstances? – Funding, Sea level rise

Vision Levels of Ecosystem Services Existing Increasing Decreasing Ecosystem Services Agricultural/aquaculture production Oyster harvest Saltwater commercial/recreational fisheries harvest Carbon/nutrient uptake Ecotourism Shoreline recreation Surge/wave attenuation Shrimp harvest Freshwater-dependent services

Science Mississippi River Hydrodynamic and Delta Management Project Two Parts: What resources are available What do we with to them

Science: Hydrodynamic How much sediment is available? How much freshwater is available? Nutrient availability and potential for wetland assimilation? When? What is the fate of these resources? What happens to the navigation channel if continued ecosystem degradation continues?

Science: Delta Management What do we do with available resources? Large scale diversions Channel re-alignment Slack water channel/sail through lock Sediment pipeline Sediment traps Nutrient sinks Driver Master Plan

National Priority Gulf Coast Ecosystem Restoration Task Force Conserve and restore habitat Restore water quality Protect and replenish living coastal marine resources Enhance Community resilience

National Priority Gulf Coast Ecosystem Restoration Task Force Looking at things like Cross cutting federal budgets Increase sediment use form river for restoration Incremental funding for better sediment management Focused effort on Lower Mississippi River Working group to develop long-term approach (NAS) Support state’s master plan – federal interest = federal funding Support LCA diversion implementation Augmenting CWPPRA with NRDA, CWA when available Declare a national emergency

Shifting Approaches Ongoing and gradual Master Plan Update MR Hydrodynamic and Delta Management Modeling and data collection on River better than ever before  Myrtle Grove, West Bay, Pass a Loutre  2011 flood response Advancing diversions More projects borrowing form river using river sediments that ever before Administration recognition

Shifting Approaches Vision We have to know where we are going Better Science We have to know how to get there National Priority We need the support of the Nation

Questions?

Future Scientific Directions EXAMPLE: MISSISSIPPI RIVER HYDRODYNAMIC & DELTA MANAGEMENT STUDY Locate diversions where project objectives best correspond to river resources EXAMPLE: MISSISSIPPI RIVER HYDRODYNAMIC & DELTA MANAGEMENT STUDY EXAMPLE: CONTINUED DEVELOPMENT OF SWAMP Have in place a robust data collection effort to be able to document the effects of project operations EXAMPLE: CONTINUED DEVELOPMENT OF SWAMP EXAMPLE: LOUISIANA APPLIED MODELING PROGRAM Feed monitoring data into a comprehensive modeling program to predict future responses of the system to continued operation and allow predictions to frame changes in operation EXAMPLE: LOUISIANA APPLIED MODELING PROGRAM Have data and outputs peer-reviewed to establish scientific credibility

LCA Mississippi River Hydrodynamic and Delta Management Study

Mississippi River Hydrodynamic Study Start with best data possible on lower river hydrodynamics and sediment transport Two-year data collection across full reach has been discussed Two-year data collection across full reach has been discussed Develop integrated 1D/2D models of hydrodynamics and sediment transport for the lower river to identify best sections of river for future diversions HEC-6T and HEC-RAS likely but not only options HEC-6T and HEC-RAS likely but not only options Develop robust 2D/3D models of hydrodynamics and sediment transport for specific sections to refine specific locations of diversions As per LCA Science Board review of West Bay Study As per LCA Science Board review of West Bay Study Strong preference for open-source, subject to peer review Strong preference for open-source, subject to peer review

Mississippi River Delta Management Study Develop up-to-date bathymetry, topography and geotechnical stability for the receiving basin adjacent to the prior-identified site Develop robust multi-dimensional hydrodynamic models for the relevant interdistributary basins Options include ADH and CH3D-SED (used for West Bay) and the State’s Delft- 3D portfolio Options include ADH and CH3D-SED (used for West Bay) and the State’s Delft- 3D portfolio Couple the hydrodynamics to land-building and ecosystem change models, possibly including predictive models for Wetland morphology and vegetation Fisheries and other upper trophic levels Options include CASM (used for LCA Mods to Caernarvon/Davis Pond) and Ecopath with Ecosim (calibrated for Caernarvon, in development for Barataria) Options include CASM (used for LCA Mods to Caernarvon/Davis Pond) and Ecopath with Ecosim (calibrated for Caernarvon, in development for Barataria) Risk assessment Such as ADCIRC, HAZUS, etc. Such as ADCIRC, HAZUS, etc.

Mississippi River Delta Management Study The strategy for dealing with all modeling needs should be to Employ cross-sector expertise for data collection and model development Utilize existing models as a foundation Improve existing models with new data and technology Explore new models with improved capabilities Subject all models and outputs to peer review to establish credibility Communicate all modeling results to relevant stakeholders The Mississippi River Hydrodynamic and Delta Management Study will tell us Where future diversions are best sited for specific purposes, and How to best operate multiple diversions over multiple years