How Will Sediment Diversions Impact Fisheries?

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How Will Sediment Diversions Impact Fisheries?

04.27.2017 | Posted by Giovanna McClenachan, Science Director, Coalition to Restore Coastal Louisiana

Prior to its leveeing and control structures, the Mississippi switched course roughly every 600 to 1,000 years, finding a more efficient route to the Gulf of Mexico as it filled with sediment. Over the course of its history, the Mississippi has had 6 Holocene delta complexes, including the most recent Atchafalaya. Each delta complex experiences stages of compaction, subsidence, and building. This delta switching, combined with the high sediment load (7th highest in the world), has resulted in the current …

Getting Down to Basics: The Environmental Impact Statement Process for the Mid-Barataria Sediment Diversion

04.05.2017 | Posted by Natalie Peyronnin, Director of Science Policy, Mississippi River Delta Restoration, Environmental Defense Fund

As CPRA advances the Mid-Barataria Sediment Diversion and other priority projects toward construction, Restore the Mississippi River Delta staff experts will aim to give you updates on key steps of the process. The Mid-Barataria Sediment Diversion aims to be “the first controlled sediment diversion reconnecting the Mississippi river with its delta,” Louisiana’s Coastal Protection and Restoration Authority (CPRA) indicated in a recent press release, and, recently, there have been some important developments toward that end. In March, CPRA announced that …

How Will a Sediment Diversion Affect the Coastal Environment? The Answer Lies in the Operations.

02.21.2017 | Posted by Natalie Peyronnin, Director of Science Policy, Mississippi River Delta Restoration, Environmental Defense Fund

Sediment diversions have long been proposed as an essential component in every major restoration plan in coastal Louisiana. Sediment diversions are man-made structures built directly into the Mississippi River levee system with gates that can be opened and closed to allow sediment, fresh water and nutrients to nourish and revive the dying wetlands. In the “Answering 10 Fundamental Questions about the Mississippi River Delta” report, scientists clearly demonstrated that sediment diversions are the most effective tool to build and sustain …

Will Diversions Introduce Nutrients That Harm Wetland Vegetation?

02.13.2017 | Posted by Theryn Henkel, Assistant Director of Coastal Sustainability Program, Lake Pontchartrain Basin Foundation

Within the scientific community, and among the general public, there is controversy over the effects that nutrients, introduced through sediment diversions, will have on wetland vegetation. The speculation is that increased nutrients, especially nitrate, will result in decreased root growth. With increased nutrient availability, plant roots will no longer have to “search” for nutrients, resulting in decreased growth. This results in fewer roots to hold and trap soil and organic matter, creating weaker wetlands. In addition, the increase in nutrients …

Diversions, Old Vegetation and New Vegetation

By Jenneke Visser, University of Louisiana at Lafayette, & Andy Nyman, Louisiana State University This is part five of the series “Building Land in Coastal Louisiana: Expert Recommendations for Operating a Successful Sediment Diversion that Balances Ecosystem and Community Needs.” See previous parts on the Sediment Diversion Operations Expert Working Group, Hydrodynamics of a sediment diversion, Geology of land building using sediment diversions, and Building land while balancing historic and cultural effects. In the last 50 years, coastal Louisiana has …

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Reconnecting the Delta: How Increased Mud Supply Can Improve Sediment Diversions

Jordan Davis, Mississippi River Delta Restoration Science Intern, Environmental Defense Fund Rising sea level and anthropogenic sediment loss is a combination affecting sustainability of deltaic ecosystems. Around the world, major deltas have been experiencing a 44% decline in sediment supply since the 1950s due to construction of dams and reservoirs, including the Mississippi River Delta. A recent journal article, published in Estuarine, Coastal and Shelf Science, examined the role of fine-grained sediments in deltaic restoration. The authors found that the …

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Building Land While Balancing Historic and Cultural Effects

08.10.2016 | By Shirley Laska, Professor Emerita of Sociology, University of New Orleans, Co-founder: Lowlander Center

This is part four of the series “Building Land in Coastal Louisiana: Expert Recommendations for Operating a Successful Sediment Diversion that Balances Ecosystem and Community Needs.” See parts one, two and three. “How a large sediment diversion along the lower Mississippi River is operated will determine the success or diminished benefit of such a very costly effort.” Building Land in Coastal Louisiana: Expert Recommendations for Operating a Successful Sediment Diversion that Balances Ecosystem and Community Needs Success will be defined by …

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Beyond the Basin: Reflections on my Upstream Upbringing

By Christina Rouse, Mississippi River Delta Restoration Projects Intern, Environmental Defense Fund Clang. A knot of rusted chains pulls shut the driveway gate, bringing it closed with a final smack against a worn fencepost. Just like that, my Sunday afternoon visit to our family farm in Clarksville, Missouri ends. After a quick trip home to Saint Louis, it’s time to catch a flight to Washington, D.C. for my internship. The road beneath our tires turns from gravel to pavement. “Do …

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The Geology of Land Building Using Mississippi River Sediment Diversions

08.03.2016 | By Dr. Alex Kolker, Louisiana Universities Marine Consortium and Tulane University

This is part three of the series “Building Land in Coastal Louisiana: Expert Recommendations for Operating a Successful Sediment Diversion that Balances Ecosystem and Community Needs.” View parts one and two. Successfully operating a sediment diversion in Louisiana requires that we understand how water and sediment naturally flow in places where the river enters the coast. The basic physical processes are relatively simple. When a sediment-rich river, like the Mississippi, enters an open bay, the flow spreads out and sediments …

Exploring the Hydrodynamics of a Sediment Diversion at Mid-Barataria

08.01.2016 | By Dr. J. Alex McCorquodale, Professor and FMI Endowed Chair, University of New Orleans

This is part two of the series “Building Land in Coastal Louisiana: Expert Recommendations for Operating a Successful Sediment Diversion that Balances Ecosystem and Community Needs.” See part one here. Historically, the Mississippi River has periodically overtopped its natural levee and flooded the adjacent wetlands with sediment-laden water. This natural process has been interrupted by the construction of flood control levees, and the available sediment has been reduced by the construction of upriver reservoirs. The proposed introduction of diversions from …

Recommendations for Operating a Sediment Diversion that Balances Ecosystem and Community Needs

07.27.2016 | Posted by Natalie Peyronnin, Director of Science Policy, Mississippi River Delta Restoration, Environmental Defense Fund

This is part one of the series “Building Land in Coastal Louisiana: Expert Recommendations for Operating a Successful Sediment Diversion that Balances Ecosystem and Community Needs.” This series will explore key recommendations for operating sediment diversions as outlined by the independent Sediment Diversion Operations Expert Working Group. The use of sediment diversions, a restoration tool that mimics the natural processes of the Mississippi River to build and sustain land, has been proposed for decades in coastal Louisiana. While we move …

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Restoration Solutions: Sediment Diversions

The State of Louisiana is advancing two sediment diversions south of New Orleans. These projects are on track to begin construction by 2020 using funding from the BP oil spill. Multiple projects working together are needed to build and sustain land, but sediment diversions are a crucial foundation needed to confront Louisiana's ongoing land loss crisis. Learn more about sediment diversions in the fact sheet below.    

Independent Scientists Release Recommendations for Building Land in Coastal Louisiana

Sediment Diversions Present Opportunity to Rebuild Louisiana’s Coast, Protect against Rising Seas FOR IMMEDIATE RELEASE Contact: Jacques Hebert, jhebert@audubon.org, 504-264-6849 (New Orleans – July 21, 2016) Today, the Sediment Diversion Operations Expert Working Group – a team of leading scientists and community experts with decades of experience working in coastal Louisiana – released key recommendations for operating Mississippi River sediment diversions to most effectively build and maintain land while considering the needs of communities, wildlife and fisheries. Sediment diversions are …

Audubon Perspectives: Witnessing Land-Building in Louisiana

07.14.2016 | By Harmony HamiltonAudubon Perspectives

Originally posted by Audubon Louisiana on July 11, 2016. See original post here. Greetings! My name is Harmony Hamilton; I am Audubon Louisiana’s inaugural Walker Communications Fellow. In this role, I will be working with Audubon Louisiana staff and supporters to capture the impact the National Audubon Society and its partners are having on birds and people across Louisiana’s coast. I recently had the opportunity to visit the Caernarvon Freshwater Diversion, just a few miles south of New Orleans, to …

LPBF Launches Hydrocoast Maps to Monitor Conditions in Barataria Basin

06.09.2016 | Posted by Theryn Henkel, Assistant Director of Coastal Sustainability Program, Lake Pontchartrain Basin Foundation

Due to popular demand, the Lake Pontchartrain Basin Foundation has created Hydrocoast Maps for Barataria Basin.  As it has done in neighboring Pontchartrain Basin, the maps for the Barataria Basin will monitor the salinity, freshwater input, weather and fisheries in order to gain a deeper understanding of estuarine dynamics, changes to the basin over time and to provide a baseline to monitor future changes as restoration projects are completed. Hydrocoast Maps provide a snapshot of the conditions of the estuary, …