Archive for Diversions
Straddling the border of Plaquemines and St. Bernard parishes in Southeastern Louisiana is the Caernarvon Freshwater Diversion built by the Army Corps of Engineers and operated since 1992 to balance water salinity by funneling river water into coastal marshes.
Lately, the diversion has had indirect effects that are raising eyebrows among scientists and those seeking to find solutions to address the crisis of Louisiana’s disappearing coast. The Caernarvon Freshwater Diversion is creating land at a rapid pace by delivering nutrient-rich river fresh water to bayous that have been starved of sediment and are eroding at an alarming rate.
In a new video, Coordinator of Lake Pontchartrain Basin Foundation’s Coastal Sustainability Program Dr. John Lopez outlines how approximately 1,000 acres of wetlands have been developed from the Caernarvon Diversion to create a new delta and within it a new bayou known as Bayou Bonjour. The new bayou is named in contrast to the book "Bayou Farewell," foretelling of the tragic loss of our wetlands and bayous. “Caernarvon was not designed or operated to build land,” Lopez notes, yet “Big Mar Pond has been filling up over the last twenty years due to sediment from Caernarvon.” How did this happen? Lopez explains how the diversion has provided an “ideal recipe for building a delta”: (river freshwater + sediments + nutrients = land growth).
Big Mar is located directly behind Braithwaite Park, a Plaquemines Parish community housed outside the federal levee system where devastation from Hurricanes Katrina, Rita, and Isaac occurred. Building land in Big Mar could provide a much-needed buffer for this community and an example for how to protect others like it. “As long as Caernarvon Diversion is flowing, this waterway and others like it will develop and this gives us hope in Louisiana that we can rebuild our coast,” says Lopez. In addition, recently planted cypress trees are thriving and will provide additional environmental and flood protection benefit as a new "line of defense."
Take a tour of Bayou Bonjour:
Want to learn more about the Caernarvon Diversion and other solutions for restoring the Mississippi River Delta? Visit mississippiriverdelta.org, like us on Facebook, and follow us on Twitter. You can also share the video with your network using the following tweet:
- Introducing Bayou Bonjour: Caernarvon Diversion has created an “ideal recipe for building a delta” #RestoreOurCoast http://youtu.be/5TExITZM2Wg
By Philip Russo, Outreach Coordinator, Restore the Mississippi River Delta Coalition
Land along a river has long been coveted for its agricultural productivity, but few rivers can compete with the mighty Mississippi.
With a drainage basin stretching across 31 U.S. states and parts of Canada, it is no surprise that the Mississippi River carries a lot of sediment. Historically, the river would deposit this sediment near its mouth in what is now southeast Louisiana, creating new land. But since leveeing of the river, the majority of this sediment is lost out the mouth of the river and into the deep waters of the Gulf of Mexico.
Near the mouth of the Mississippi, the final 85-mile stretch of the Mississippi River in Plaquemines Parish is home to prodigious citrus farming land. And with cool temperatures and clear skies, the weather of early December was ripe for the 68th Annual Plaquemines Parish Orange Festival.
Nestled between the Mississippi River levee and historic Fort Jackson, the focus of the festival is all things citrus. In Louisiana, that means copious displays of red navels, tangelos, ruby red grapefruits, sweet oranges, satsumas, kumquats and more.
While we attended and blogged about our trip down to the Orange Festival last year, this was the first year we actively engaged the crowds about protecting and restoring our coast – and we got to do so while debuting our tabletop river delta model! Watch this short video of the diversion model in action.
There are some sections of Plaquemines Parish where the distance between the Mississippi River levee and the Barataria Bay levee is only a few hundred yards, so Plaquemines residents are familiar with and usually eager to talk about their coast. But having a model demonstrating the process which built the very land everyone is standing adds another dimension to conversations about restoring barrier islands, ridges and marsh.
This year’s Orange Festival celebrated yet another successful harvest, but the celebration – originally organized in 1947 to promote Plaquemines’ citrus crop – has known its setbacks, most significantly due to Hurricanes Betsy, Camille and Katrina. If we are going to ensure the success of future harvests, we need to restore our multiple lines of defense against storm surge and maintain our protective coastal wetlands with strategically located and operated diversions along the river.No Comments
By Theryn Henkel, Ph.D., Lake Pontchartrain Basin Foundation
The Coastal Sustainability Program at the Lake Pontchartrain Basin Foundation (LPBF) recently released an article titled “Examination of Deltaic Processes of Mississippi River Outlets–Caernarvon Delta and Bohemia Spillway in Southeastern Louisiana” in the Gulf Coastal Association of Geological Societies Journal. The article details work that LPBF has done investigating the development of the Caernarvon Delta and operation of the Bohemia Spillway, both located in Plaquemines Parish, La.
Natural land-building deltaic processes of the Mississippi River Delta have been severely limited by artificial river levees, which prevent water and sediment from flowing over the banks during spring floods. To counteract the effects of severing the connection between the river and the delta, focus has been placed on reconnecting the river to the surrounding wetlands by the creation of artificial outlets, also called diversions.
The Caernarvon Freshwater Diversion was designed to deliver up to 8,000 cubic feet per second (cfs) of water from the Mississippi River. For reference, a flow rate of 8,000 cfs could fill up an Olympic-size swimming pool in 11 seconds or the Superdome in 4.5 hours. The Mississippi River also contains sediment that is carried along with the fresh water through the Caernarvon Diversion into the adjacent wetlands or open water, where it can nourish the wetlands and/or build land.
LPBF collects data on the turbidity, or cloudiness, of the water diverted through the diversion. Through established equations, the cloudiness of the water can be related to sediment load or the amount of sediment carried in the water. From this, it was calculated that the total amount of sediment carried into the wetlands and open waters areas from 2009 to 2012 was 264,000 cubic yards, or a volume equal to 81 swimming pools. Due to other considerations, the diversion is not always operated when the sediment load in the river is high and therefore does not maximize potential sediment capture. Despite this variability in operation of the diversion – and the fact that the Caernarvon Diversion was built to minimize sediment capture, as it was built solely for salinity control, not land building – there actually has been enough sediment diverted by the Caernarvon Diversion to build a new delta. Total wetland growth of the delta in the open water area receiving diverted water from 1998 to 2011 was 600 acres. This new wetland area is lush and thriving with a variety of plant species (trees and herbaceous) growing, and alligators, birds and insects abound.
The Bohemia Spillway is an 11-mile stretch along the east side of Mississippi River south of New Orleans where the federal protection levees were removed. It was created in 1926 by the removal of existing artificial river levees, thereby allowing river water to flow over the banks and into the adjacent wetlands when the river was high. This overflowing process is how the river would have operated historically.
In 2011, the Mississippi River watershed experienced an historic flood which provided an ideal opportunity to investigate and study how the spillway operates. When the river overflows its banks, if brings fresh water, nutrients and sediment to the wetlands. This cannot happen when the connection is cut off by levees. The severing of the connection of the river to the wetlands is one of the contributing factors to the high rates of land loss rates experienced by southeast Louisiana.
Current land loss rates in the Bohemia Spillway are negligible, perhaps due to receiving inputs of fresh water, nutrients and sediment during high river events since 1926. We have not observed delta formation in the Bohemia Spillway, as we did at the Caernarvon Diversion, but we have observed the infilling of defunct navigation and oil and gas canals as they slowly convert back to land.
In many parts of Louisiana’s coast, man-made canals often contribute to increased land loss. Poorly maintained canals erode and become wider, and salt water is conveyed through the canals into adjacent fresh marshes, killing plants and converting land to open water. Therefore, seeing canals infilling and low rates of land loss in the Bohemia Spillway indicates that the restoration of somewhat normal processes, by reconnecting the river to the wetlands since 1926, has had a positive effect on the area.
For both Bohemia Spillway and the Caernarvon Diversion, there are clearly benefits to sustaining or increasing wetland areas. However, the two outlets also provide a contrast in the future possibilities. Precisely replicating the Bohemia Spillway by levee removal is generally not feasible because of the ongoing need for protection from river floods. However, a controlled diversion built and operated to more efficiently capture and deliver sediment in ways that emulate more natural processes, such as in the Bohemia Spillway, may hold great promise for coastal restoration, rather than the obsolete design and operational goals of a diversion such as Caernarvon.No Comments
By Erin Greeson (National Audubon Society) and Alisha Renfro (National Wildlife Federation)
While there is no question that large-scale action is urgently needed to add address Louisiana’s land loss crisis, some questions surround the scientific solutions necessary to address this challenge. As the state of Louisiana advances its Coastal Master Plan and the comprehensive set of restoration projects within it, experts have opened discussion to scientists and interested members of the public to provide information, share science and encourage dialogue.
This week in New Orleans, the Expert Panel on Diversion Planning and Implementation had their second meeting, which offered an opportunity to reconvene for updates and discussion on sediment diversions – one of the key tools in Louisiana’s coastal restoration toolbox. In addition to addressing environmental concerns, the panel addressed social and economic questions about river diversions and the communities they will impact.
At the start of the meeting, Mr. King Milling, Chair of the Governor’s Advisory Commission on Coastal Protection, Restoration and Conservation, delivered a powerful reminder of Louisiana’s disappearing coast:
“Demise of this delta would be an environmental impact of international proportions: disaster for economy, culture, communities – all the things we do and live for in the delta. If we don’t proceed urgently, we will lose the delta. Nothing will stop this damage if we don’t proceed in an orderly fashion with large-scale, comprehensive solutions. This is not a time for debate. Our role is to address the issue of remarkable deterioration, and the state’s diversion committee will be addressing issues and conflicts. Its position is to focus on the larger picture of how we can preserve as much as we can, and how can we create a system that will protect as much as we can.”
The first day of the meeting was open to the public, and the agenda reflected many of the areas of focus that require follow-up from the panel’s first meeting. Presentations from the Army Corps of Engineers, The Water Institute of the Gulf and Biedenharn Group focused on the Hydrodynamic Study, which is collecting data in the river and using models to represent conditions in the river as it is today, predicting what the river will be like in the future without diversion projects and how the construction and operation of diversion projects change the river compared to the future without the diversions. They also briefly discussed the Mississippi River Delta Management Study, expected to begin soon, which will focus on the basin-side effects of diversions and evaluate combinations of diversion projects that maximize the number of acres of wetlands built or sustained over time.
Presentations from David Lindquist from the state’s Coastal Protection and Restoration Authority (CPRA) summarized the current state of knowledge on fisheries and wildlife response to existing freshwater diversions. Craig Colten, Ph.D. from the Water Institute of the Gulf highlighted the importance of considering the influences of restoration projects on communities.
A presentation from Micaela Coner and Bob Beduhn narrowed the discussion down to the engineering and design considerations of a single project – the Mid-Barataria Diversion. Ms. Coner, CPRA, discussed the Mid-Barataria sediment diversion project within the context of the 109 Coastal Master Plan projects. Speaking to the plan’s theme of reconnecting the river with its estuaries, she described sediment diversions as the best opportunity to build, maintain and sustain land.
Dr. Robert Twilley, Louisiana State University, described how the river once built natural resource wealth: “Natural resource economies and the flooding of the river once coexisted. The wealth of fisheries, and the wealth of the river building wetlands, once coexisted. Today, there’s a conflict. Historically, the river built land during big flood events. Nature had this figured out. We’re forcing a conflict. There is a resolution to this.”
During the closing portion of the meeting, attendees had opportunities to provide comments to the Expert Panel. Mississippi River Delta Restoration Coalition leaders were among the conversation.
David Muth of the National Wildlife Federation urged the panel to consider the historical context of the river in addressing site-specific questions about diversions: “We have glimpses from historical record about how productive this system once was. But for the past 300 years, we have been choking off that system.”
John Lopez of the Lake Pontchartrain Basin Foundation described the coastal land loss crisis in powerful terms and underscored for a sense of urgency: “This house is on fire. Lives are at risk. We have a great scientific challenge, but we don’t have time to delay.”
More background on the Expert Panel:
During its first meeting in January, the Expert Panel was asked to focus on the topics of uncertainty – underlying natural variability and limitations in knowledge – they perceived surrounding the design and operation of major freshwater and sediment diversions. A report summarizing their findings and recommendations from that first meeting was released in February.
In this report the panel focused on identifying six areas that should be answered or considered as sediment diversions move further from idea into planning, engineering and design:
- Data collection is important for understanding the system as it is today and for evaluating performance of individual diversion projects.
- A controlled sediment diversion does not currently exist, but some information needed to understand the time scales and extent of land building that could be expected from a controlled sediment diversion can be gleaned from natural crevasses.
- The response of plant, fish and wildlife communities to the operation of sediment diversions should be incorporated into modeling of different scenarios, both capacity and operation, of a diversion.
- The potential social and economic influences of a diversion project need to be considered to minimize any potential negative impacts that can be foreseen.
- Planning and design of diversion projects need to be explored under present day and possible future conditions (e.g. sea level rise, changes in precipitation) to maximize project success in the very near and long-term future.
- Communications between planners and stakeholders to discuss the realities and limitations of any predictions is essential for project success.
By Alisha A. Renfro, Ph.D., National Wildlife Federation
As spring weather warms the Midwest, snow melts and drains from 31 states into the Mississippi River. In south Louisiana, the mighty Mississippi River is nearing its peak flow of nearly 900,000 cubic feet of water per second. Rolling down the river with the water is mud and sand, which are essential to building wetlands in the disappearing Mississippi River Delta.
Every hour in Louisiana, a football field of land becomes open water. This land loss crisis is caused in part by levees built for flood protection and navigation which severed the connection between the delta and the river, almost completely halting the land-building processes that once created this iconic landscape.
Sediment diversions are large-scale restoration projects that move sand and mud from the river through the levees into nearby wetlands during high river flows – such as this year’s spring high water flow – to restart the land-building process and help sustain existing wetlands. One important question to understand the full land-building potential of these projects is: Is the Mississippi River a long-term, sustainable source of mud and sand?
A recent Nature Geoscience paper by Jeffrey Nittrouer, Ph.D. of River University and Enrica Viparelli, Ph.D. of the University of South Carolina, “Sand as a stable and sustainable resource for nourishing the Mississippi River delta,” suggests that while the amount of mud carried by the Mississippi River has decreased since the 1970s, the sand it carries has remained steady and may do so for the next 600 years.
The Missouri River is an important source of sediment to the Mississippi, historically supplying about one-half of the total sediment moving down the Mississippi River. However, dams built in the 1950s along the Missouri have been hypothesized as the cause of the large reduction in the amount of total sediment (mud plus sand) that makes its way down to the Mississippi.
In this study, Nittrouer and Viparelli look at changes in the mud and sand carried by the river over a year since the 1970s and found that while the amount of mud that makes it to Tarbert Landing, Miss. (306 miles above the Bird’s Foot delta) has decreased over time, the amount of sand has been consistent. They point out that the likely source of sand is material that is being eroded out of the river channel.
Nittrouer and Enrica applied a model to simulate the response of a sudden reduction in sediment supply that likely occurred with dam construction along the Missouri River in the 1950s. The model indicates that erosion of sand in the river channel between Cairo, Ill. and Vicksburg, Miss. keeps the amount of sand available at Tarbert Landing, Miss. steady for the next 600 years.
Sand and mud are both needed to restore the Mississippi River Delta. Sand, which is 20 percent of the sediment carried by the river, is essential for building new platforms that can support marsh vegetation. Mud, which makes up the other 80 percent, is necessary for maintaining and increasing the resiliency of existing marsh to sea level rise and storm events.
This study suggests that there is a steady supply of sand to the lowermost part of the Mississippi River that can be put to work by constructing and using sediment diversions to mimic nature to build new land, help sustain existing wetlands and begin the restoration of the Mississippi River Delta. This is positive news for large-scale coastal restoration efforts.No Comments
This was originally posted by Environmental Defense Fund on EDF Voices.
By Estelle Robichaux, Restoration Project Analyst, Environmental Defense Fund
Soon after my flyover of the Mississippi River Delta, I joined Dr. John Lopez of the Lake Pontchartrain Basin Foundation (LPBF) on a boat ride down the Bohemia Spillway to Mardi Gras Pass. As we sped down the spillway canal, beautiful swamp lilies and purple morning glories popped out against a backdrop of lush, green plants. Once we reached our destination, we saw an incredible number of birds: Laughing Gulls, Snowy Egrets, Great Blue and Tricolored Herons – just to name a few. This, along with an increase in the number of river otters and beavers observed, is a good indicator that there are healthy fish populations in the area.
Thirty-five miles southeast of New Orleans, Mardi Gras Pass is the Mississippi River’s newest and naturally evolving “distributary,” a channel of water that flows away from the main branch of the river. This new distributary began forming during the spring flood of 2011, when the water level of the Mississippi River was so high that it flowed over the natural levee in this area. When the floodwaters receded, Dr. Lopez and his team of scientists noticed two breaches in the embankment. These breaches continued to widen and deepen and soon, right around Mardi Gras Day 2012, the breach was complete. The Mississippi River was once again connected to the surrounding wetlands, allowing freshwater and land-building sediment back into the area.
Louisiana has lost 25% of its coastal land area since 1930 and continues to lose land at an alarming rate – one football field every hour, on average. Man-made levees along the Mississippi River cut off many small distributaries, like Mardi Gras Pass, from the wetlands in the floodplain of the river and have contributed to this massive wetland loss. Our team here at EDF works with partner organizations, including the Lake Pontchartrain Basin Foundation, as part of the Mississippi River Delta Restoration Coalition, which has a vision of reconnecting the Mississippi River to its delta to help protect people, wildlife and jobs in coastal Louisiana.
To address the complex, yet urgent need for coastal restoration in Louisiana, the state legislature unanimously passed the 2012 Coastal Master Plan. This plan is a long-term, science-based restoration program that includes nearly 250 restoration projects such as barrier island restoration, marsh creation, establishment of oyster barrier reefs and sediment diversions that will help rebuild Louisiana’s disappearing coast.
Restoring our coast, restoring my hope
One of the principal guidelines for restoration under the Coastal Master Plan is to address the root causes of land loss by using the natural power of the Mississippi River to build land at a large scale. Sediment diversions, a central component of the plan, embody this principle because they are designed to mimic the natural stages of the river and carry sediment to the areas of coastal Louisiana that need it most. By operating diversions at times of high water flow (like during a flood), large amounts of sediment can be diverted. It will then settle out in the wetlands and shallow bays, eventually building land mass in vulnerable coastal areas.
In a way, Mardi Gras Pass is a naturally occurring ‘pilot project’ of a sediment diversion. Knowledge gained from studying this area can tell us about the land-building properties, as well as the short-term effects, of sediment diversions. To learn more about this, LPBF scientists are studying how the reintroduction of freshwater and sediment to the spillway area is changing the wetlands and affecting wildlife populations.
Swift currents and downed trees along the edge of the flooded forest can make navigating Mardi Gras Pass somewhat treacherous, but we, in a trusty 14’ skiff, maneuvered through the channel and onto the Mississippi River for a brief but thrilling cruise.
This is what it means for the river to be connected to its floodplain, I thought as we emerged out onto the open water, this is what this ecosystem is supposed to be like.
Although I grew up only a few miles from it, this was the third time in my life I had been out on the Mississippi River and the first time it was in a boat small enough that I could reach down and touch its muddy waters. As our tiny boat circled out in that mighty river, despite the heat and the midday sun, I had goose bumps.No Comments
By Alisha A. Renfro, Ph.D., National Wildlife Federation
Last week in Baton Rouge, The Water Institute of the Gulf hosted the inaugural meeting of the Expert Panel on Diversion Planning and Implementation. The panel – comprised of 12 experts in natural and social sciences, engineering and economics – was selected from more than 60 nominees from across the country. Panel members are all from outside Louisiana, in order to foster critical and constructive review of work being led by Louisiana-based experts. Under the direction of The Water Institute of the Gulf and meeting up to three times a year, this independent panel will provide technical review, input and guidance as the state moves forward and refines its plans for diverting fresh water and sediment from the Mississippi and Atchafalaya Rivers to build, maintain and sustain coastal wetlands. For this first meeting, the panel was asked to consider the most suitable approaches to addressing current or perceived uncertainties in the planning and design of sediment diversions.
The first day of this meeting was open to the public and included a series of presentations outlining the urgent need for restoration in coastal Louisiana as well as various perspectives on sediment diversions. Kyle Graham, Deputy Executive Director of the Coastal Protection and Restoration Authority (CPRA), summarized Louisiana’s 2012 Coastal Master Plan. In his presentation, Graham pointed out that there was no single restoration project type that can address the state’s land-loss crisis in one fell swoop, but that a suite of restoration projects are needed, including barrier island restoration, marsh creation, oyster barrier reefs, shoreline protection, hydrologic restoration and sediment diversions. Barrier island restoration and marsh creation can mechanically create land in strategic locations, but sediment diversions convey sediment to not only build new land but also to maintain existing wetlands that would otherwise be lost.
Brigadier General Duke DeLuca, Commander of the U.S Army Corps of Engineers’ Mississippi Valley Division, presented the Corps’ perspective on sediment diversions. DeLuca discussed some of the questions that the Corps would like to see answered as sediment diversions move from plan to implementation. Many of these outstanding questions should be directly addressed through the Mississippi River Hydrodynamic and Delta Management Study, a joint project being conducted by the State of Louisiana and the Corps. The study will use historic and field data, along with models, to do an assessment of large-scale restoration features to address sustainability of the Mississippi River Delta.
Additional presenters included Jim Tripp from Environmental Defense Fund, Michael Massimi from the Barataria-Terrebonne National Estuary Program, Dr. Ehab Mesehle from The Water Institute of the Gulf and Dr. Alaa Ali from South Florida Water Management District.
In a late afternoon panel, Mark Wingate and Martin Mayer of the Corps’ New Orleans District, John Ettinger of the Environmental Protection Agency and Ronnie Paille of U.S. Fish and Wildlife Service, discussed their federal agencies’ views on diversions. Afterwards, the public was given the opportunity to voice their thoughts and concerns about coastal restoration directly to the panel.
The following day, panel members met in private to discuss the uncertainties discussed and the science that needs to be done to address these uncertainties. A report on that meeting will be given at a CPRA meeting in the coming months.
Bold solutions are needed to halt the rate of catastrophic land loss in coastal Louisiana. Every year, communities throughout the coast inch closer to disaster, becoming more and more exposed to the destructive forces of storm events. Infrastructure, which is vitally important to the economy of Louisiana and the nation, becomes more vulnerable, and important habitat for wildlife, fish and birds vanishes.
Limited by money and sediment resources, there is no one type of restoration project that is a cure-all solution. A suite of restoration projects that strengthen and sustain the landscape is necessary. Sediment diversions use the natural power of the river to build new land and help maintain the existing wetlands. To do nothing or to only implement the least challenging types of restoration projects would doom the resource-rich Louisiana coast.No Comments
National Fish and Wildlife Foundation Announces Nearly $68 Million for Louisiana Restoration ProjectsNovember 14, 2013 | Posted by Ryan Rastegar in 2012 Coastal Master Plan, Media Resources, Mid-Barataria Sediment Diversion, Restoration Projects
FOR IMMEDIATE RELEASE
Erin Greeson, National Audubon Society, 503.913.8978, email@example.com
Emily Guidry Schatzel, National Wildlife Federation, 225.253.9781, firstname.lastname@example.org
Elizabeth Skree, Environmental Defense Fund, 202.553.2543, email@example.com
National Fish and Wildlife Foundation Announces Nearly $68 Million for Louisiana Restoration Projects
$40.4 million dedicated to Mid-Barataria Diversion, a critical project to comprehensive coastal restoration
(New Orleans, LA – November 14, 2013) Today, leading national and local conservation and restoration organizations – Environmental Defense Fund, National Audubon Society, National Wildlife Federation, Coalition to Restore Coastal Louisiana and the Lake Pontchartrain Basin Foundation – released the following joint statement:
“We applaud the National Fish and Wildlife Foundation (NFWF), in partnership with Louisiana’s Coastal Protection and Restoration Authority, for dedicating $67.9 million to seven key barrier island and river diversion projects, including $40.4 million for the Mid-Barataria Diversion project. The Barataria Basin has one of the highest rates of land loss in the world, and this large-scale wetland restoration project is crucial to reversing that trend.
“The mid-sized Mid-Barataria sediment diversion is a key component of Louisiana’s 2012 Comprehensive Master Plan for a Sustainable Coast. The master plan is a blueprint for restoring the Mississippi River Delta and Louisiana’s coast and contains a suite of coastal restoration and protection projects. Our organizations support the full suite of restoration projects in that plan, of which the Mid-Barataria Diversion is a critical piece.
“Restoration of Louisiana’s disappearing wetlands is important not only to Louisiana but to the entire nation. Louisiana’s wetlands and waters provide one-third of the nation’s seafood, are a stopover point for migratory birds traveling the Mississippi Flyway and provide critical wildlife habitat. Projects like the Mid-Barataria Diversion can help revive Louisiana’s coastal wetlands – part of America’s largest delta – to a productive, functioning state, which provides important ecological and economic opportunities for people and wildlife. We look forward to continued work with both the National Fish and Wildlife Foundation and the State of Louisiana to implement the Mid-Barataria sediment diversion on its current timeline of being ready for construction in 2015.”
By Alisha Renfro, Coastal Scientist, National Wildlife Federation
The Mississippi River is one of the most managed river systems in the world. However, that management has focused on navigation and flood control needs to the detriment of the economically and ecologically important coastal Louisiana landscape. This week, the U.S. Army Corps of Engineers and Louisiana’s Coastal Protection and Restoration Authority (CPRA) hosted a public meeting in New Orleans to present information and preliminary results of their joint effort on the Mississippi River Hydrodynamic and Delta Management Study. This large-scale, long-term study is developing tools to evaluate different combinations of restoration projects in an effort to address the long-term sustainability of the Mississippi River and its delta while balancing the needs of navigation, flood protection and restoration.
The scope of the study extends from Vicksburg, Miss. south to the Bird’s Foot delta. The study is actually comprised of two coupled, but somewhat distinct, efforts. The hydrodynamic portion of the study will focus on characterizing the dynamics in the river and developing models that can be used to evaluate river-side changes due to proposed freshwater and sediment diversion projects. It will also inform location and design of these projects to maximize their effectiveness and minimize the potential for shoaling in the river’s navigation channel. The delta management part of the study will focus on the basin-side benefits and changes caused by these restoration projects. The delta management portion of the study has not yet begun. Currently, the state of Louisiana and the Army Corps are working to define the depth and breadth of that part of the study.
The afternoon session of the meeting focused on detailed technical presentations on the study. The different tasks of the Mississippi River Hydrodynamic and Delta Management Study include a geomorphic assessment, data collection and an extensive modeling effort. The geomorphic assessment focuses on compiling historical river data, dredging records and satellite imagery to document the historical trends in the river. The data collection effort will compile existing data and conduct field work to fill in gaps in understanding of the water and sediment dynamics that currently exist in the river. The historical data and present data will be integrated into the modeling work to inform the models and to ensure that the models capture the dynamics of the river system. The modeling effort includes a suite of models that each has different strengths and weaknesses. These models will be used to forecast the large-scale, long-term and shorter-term regional changes expected in the river in both a future without river diversions and a future that includes different combinations of diversion projects.
The presentations from the technical meeting indicate that this collaborative state of Louisiana and Army Corps effort has moved forward significantly since it began. The geomorphic assessment has been completed and a final report on its results is expected by the end of this year. The data collection effort is ongoing, having captured the low discharge of the river last year and the higher flow discharge from this past spring. Many of the preliminary model simulations have begun, and the preliminary results presented at this meeting emphasized the dynamic nature of the Mississippi River system, where water discharge, sediment transport and deposition can not only vary greatly from year to year, but also from week to week. The preliminary results also point to the importance of appropriate size, location and operation of sediment diversions in order to maximize sediment conveyance into adjacent wetlands and to reduce potential riverside impacts.
The Mississippi River has been a key feature in the growth and development of the U.S. However, for more than 80 years, the management of the river has focused on balancing the needs of navigation and flood control. A shift away from that management scheme towards one that balances navigation, flood control and restoration is absolutely critical for the survival of the delta ecosystem and, ultimately, the communities and navigation industry that depend on the Mississippi River Delta. The Hydrodynamic and Delta Management study is poised to be the effort that changes the way we think about management of the river and how we build a more sustainable, holistic system for our future.No Comments
Conservation Groups Respond to Mid-Barataria Sediment Diversion Environmental Impact Statement LaunchOctober 8, 2013 | Posted by Elizabeth Van Cleve in Media Resources, Mid-Barataria Sediment Diversion
FOR IMMEDIATE RELEASE
CONTACTS: Erin Greeson, National Audubon Society, 503.913.8978, firstname.lastname@example.org
Emily Guidry Schatzel, National Wildlife Federation, 225.253.9781, email@example.com
Elizabeth Skree, Environmental Defense Fund, 202.553.2543, firstname.lastname@example.org
Conservation Groups Respond to Mid-Barataria Sediment Diversion Environmental Impact Statement Launch
Corps’ intention to conduct EIS seen as crucial step forward
(New Orleans, LA – October 8, 2013) Today, a coalition of leading national and local conservation and restoration organizations – Environmental Defense Fund, National Audubon Society, National Wildlife Federation, Coalition to Restore Coastal Louisiana and the Lake Pontchartrain Basin Foundation– released the following joint statement:
"The U.S. Army Corps of Engineers announced in last Friday’s Federal Register their intention to conduct an Environmental Impact Statement on the Mid-Barataria Sediment Diversion. The Mid-Barataria Sediment Diversion will be the first major controlled sediment diversion reconnecting the Mississippi River with its delta. It is a cornerstone of the state’s master plan for sustaining our coast.
"The Mississippi River Delta Restoration Campaign believes that launching the Environmental Impact Statement is an important step forward for the project. Given the urgency of restoring and sustaining our coast, a thorough and rigorous Draft Environmental Impact Statement should be completed by fall of 2014, with final review and permits issued by spring of 2015. We look forward to collaborating with the Corps and its state and federal partners to achieve this exciting and crucial 2015 construction goal. Our coast can’t wait. It's time to get together and get it done.”
The Restore the Mississippi River Delta coalition is working to protect people, wildlife and jobs by reconnecting the river with its wetlands. As our region faces the crisis of threatening land loss, we offer science-based solutions through a comprehensive approach to restoration. Comprised of conservation, policy, science and outreach experts from Environmental Defense Fund, National Audubon Society, National Wildlife Federation, Coalition to Restore Coastal Louisiana and Lake Pontchartrain Basin Foundation, we are located in Houma, New Orleans and Baton Rouge, Louisiana; Washington, D.C.; and around the United States. See more at www.mississippiriverdelta.org.No Comments