Myrtle Grove Diversion Modeling Reveals New Information on Land-building Potential

By Maura Wood, National Wildlife Federation

Barataria Basin Finite Element Grid, Moffatt & Nichol

The Myrtle Grove Medium Diversion is one of five highest priority near-term Louisiana Coastal Area (LCA) restoration projects authorized by Congress in the Water Resources Development Act of 2007.  It is also one of a handful of projects authorized with the express authority to make changes in the project to respond to the impacts of Hurricanes Katrina and Rita.  This opens the opportunity to modify Myrtle Grove to divert sediment and build land.

In order to examine modifications and how they might improve (or not) the benefits and impacts of the project, the Office of Coastal Protection and Restoration (OCPR) and several non-profit conservation organizations entered into a unique collaboration to undertake an extensive data-gathering and modeling initiative.  The purpose of the modeling was to bring the best science and modeling into the planning process, to modify the diversion to capture sediment and build land, and to answer stakeholder questions.

A body of results from this effort was released on June 7 at a science workshop organized by the National Wildlife Federation and OCPR titled “Developing a Scientific Approach for Sediment Diversions: Myrtle Grove as a Model of Data Collection, Modeling, and Design.”  Eighty-seven people, including scientists, academics and agency representatives, NGOs, contracting firms and stakeholders, participated in the session.

Results include new information on the bathymetry and hydrodynamics of the specific reach of the Mississippi River, projection of  sediment loading potential through a modified Myrtle Grove diversion at different discharge capacities, and analysis of hydrodynamic and salinity changes that could be expected under different discharge and operational regimes.

Presentations and other papers on the modeling are available at ftp://ftp.dnr.state.la.us/lcamyrtlegrove until July 4.