Optimizing Sediment Diversion Operations: Working Group Recommendations for Integrating Complex Ecological and Social Landscape Interactions
Environmental Defense Fund, Washington, DC 20009, USA
Louisiana State University, Baton Rouge, LA 70803, USA
Louisiana Universities Marine Consortium, Chauvin, LA 70344, USA
Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA 70118, USA
University of New Orleans, New Orleans, LA 70148, USA
The Lowlander Center, Gray, LA 70359, USA
Department of Biological Sciences, Nicholls State University, Thibodaux, LA 70301, USA
Institute for Coastal and Water Research, University of Louisiana at Lafayette, Lafayette, LA 70504, USA
Author to whom correspondence should be addressed.
Academic Editor: Roger A. Falconer
Water 2017, 9(6), 368; https://doi.org/10.3390/w9060368
Received: 11 April 2017 / Revised: 11 May 2017 / Accepted: 11 May 2017 / Published: 24 May 2017
(This article belongs to the Special Issue The Effects of Aquatic Habitat Restoration or Degradation on Fish Production)
Future conditions of coastal Louisiana are highly uncertain due to the dynamic nature of deltas, climate change, tropical storms, and human reliance on natural resources and ecosystem services. Managing a system in which natural and socio-economic components are highly integrated is inherently difficult. Sediment diversions are a unique restoration tool that would reconnect the Mississippi River to its deltaic plain to build and sustain land. Diversions are innately adaptable as operations can be modified over time. An expert working group was formed to explore how various operational strategies may affect the complex interactions of coastal Louisiana’s ecological and social landscape and provide preliminary recommendations for further consideration and research. For example, initial operations should be gradually increased over 5 to 10 years to facilitate the development of a distributary channel network, reduce flood risk potential to communities, limit erosion of adjacent marshes and reduce stress to vegetation and fish and wildlife species. Diversions should operate over winter peaks to capture the highest sediment concentration, reduce vegetation loss while dormant, and reduce detrimental effects to fish and wildlife. Operations during the spring/summer should occur over shorter periods to capture the highest sediment load during the rising limb of the flood peak and minimize impacts to the ecosystem. Operational strategies should strive to build and sustain as much of the coastal landscape as possible while also balancing the ecosystem and community needs.