Archive for Diversions
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 closer to construction of a sediment diversion, the issues surrounding how the reintroduction of fresh water and sediment will impact the ecosystem, including important fish and wildlife species, and the communities that live, work and play in the basin, require close monitoring and planning.
The state of Louisiana, through the Coastal Protection and Restoration Authority (CPRA), will be required to develop an Operation and Adaptive Management Plan that lays out strategies that need to be considered when operating a sediment diversion to maximize land building, while balancing the needs of the ecosystem and communities.
To help CPRA with developing these strategies, the Sediment Diversion Operations Expert Working Group was formed. The working group consisted of 12 interdisciplinary scientists with a wide range of on-the-ground expertise in coastal Louisiana. Together, they released a report with the goal of providing specific recommendations to begin a robust discussion on operation strategies to be considered for CPRA’s plan.
The working group members, along with over 40 guest experts, discussed, debated and documented complex issues such as wetland health, basin geology, fish and wildlife species and socio-economics. The resulting recommendations are included in the report, Building Land in Coastal Louisiana: Expert Recommendations for Operating a Successful Sediment Diversion that Balances Ecosystem and Community Needs.
Five of the topics key to the successful operation of a sediment diversion – sediment, hydrodynamics, vegetation, socio-economics, and fish and wildlife – will be explored further in this blog series written by experts in their respective subject. This series is intended to further detail these important topics that will become extremely relevant once a diversion is constructed.
Stay tuned for the next post in the “Building Land in Coastal Louisiana” series about key recommendations concerning hydrodynamics, titled “Exploring the Hydrodynamics of a Sediment Diversion at Mid-Barataria.”
For more information about the Sediment Diversion Operations Expert Working Group’s key recommendations, visit http://www.mississippiriverdelta.org/diversion-ops-report/.
Natalie Peyronnin is the director of science policy for EDF's Mississippi River Delta Restoration program and the convener of the Sediment Diversion Operations Expert Working Group. She works to ensure sound science is being utilized to plan, design, implement and adaptively manage projects and policies, with a focus on system dynamics. Natalie was a Senior Scientist for Louisiana’s Coastal Protection and Restoration Authority, where she served as the technical lead and science communicator for the 2012 Coastal Master Plan. Natalie also worked as Science Director for the Coalition to Restore Coastal Louisiana. Natalie has a B.S. in Wildlife and Fisheries Management, with minors in Forestry and Zoology & Physiology from Louisiana State University, as well as an M.S. in Oceanography and Coastal Sciences from Louisiana State University.
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.No Comments
By Estelle Robichaux, Restoration Project Analyst, Environmental Defense Fund and Gaby Garcia, Science Intern, Environmental Defense Fund
This post is part of a series on early restoration planning in Louisiana. Be sure to check out part one for a look back to 1973.
In 1988, the Coalition to Restoration Coastal Louisiana (CRCL) released a plan titled Coastal Louisiana: Here today and gone tomorrow? The plan, which was a joint effort by stakeholders and scientists, focuses on the Mississippi River Delta region and is framed as a citizens program for protecting Louisiana’s environment, economy and heritage.
The plan provides nearly 20 recommendations, including a restoration action program, suggestions for how to finance the program, as well as specific institutional and legislative recommendations designed to galvanize restoration.
Among the most notable elements is the assertion that sediment diversions would be the most beneficial method of wetland restoration and that several of them should be constructed along the Mississippi and Atchafalaya Rivers. This was also one of the first plans to advise against any new levee construction.
Many of the plan’s most significant propositions, those focused on restoration action, have yet to be realized, though the science behind sediment diversions is well developed and we continue to advocate for them as a sustainable restoration tool.
A bold but realistic plan of action
CRCL’s plan has two specific resource goals that are still strongly advocated for:
- To utilize freshwater and sediment diversions along the Mississippi River and Atchafalaya Rivers to sustain and restore coastal wetlands;
- To beneficially use dredged material from channel maintenance and existing spoil banks to backfill canals and nourish created wetlands and barrier islands
Restoring natural processes: Mississippi River water & sediment diversions
The Caernarvon and Davis Pond diversions were still being designed at the time this plan was published. Although there were expectations these structures would help control saltwater intrusion and reduce wetland loss, the plan underscores their limitations in active wetland restoration and land building. Despite the fact these diversions were designed for salinity and flood control, both areas have seen new land growth, though not at the scale or rate anticipated for sediment diversions.
The action program calls for the construction of a suite of freshwater and sediment diversions to restore hydrologic connections and halt wetland loss. The essence of many of these restoration ideas can be found in Louisiana’s 2012 Coastal Master Plan (CMP). Some of the restoration actions proposed in the 1988 plan include:
- One or two diversions from the Atchafalaya River into the Lake Verret Basin and Western Terrebonne marshes.
- 2012 CMP: Two diversions from the Atchafalaya will increase freshwater and sediment flows into Terrebonne marshes from Bayou Penchant westward, including our of our coalition’s 19 priority projects, Increase Atchafalaya Flow into Terrebonne Marshes.
- Restoration of Bayou Lafourche into a distributary of the Mississippi River, with a diversion into Timbalier Bay.
- 2012 CMP: Small-scale freshwater diversion from the river into Bayou Lafourche.
- Freshwater and sediment diversions, at Bayou Manchac and Blind River, to bring Mississippi River water into the degraded swamps south of Lake Maurepas.
- 2012 CMP: Two freshwater diversions, at Blind River and Hope Canal, and hydrologic restoration of the Amite River to restore freshwater inputs to Lake Maurepas, including one of our priority projects, West Maurepas Diversions.
- A large-scale sediment diversion of the Mississippi River below New Orleans into Barataria Basin and a navigation channel from the river into Breton Sound in the vicinity of Empire.
- 2012 CMP: Two sediment diversions into Barataria Basin in the vicinity of Diamond and Myrtle Grove, Lower and Mid-Barataria Sediment Diversions (also two of our coalition’s priority projects).
Beneficial use of dredged material
In addition to the focus on restoring natural processes by using freshwater and sediment diversions, the plan has another major component that concentrate on restoration actions that would provide short-term benefits as well as some regulatory changes. This component focuses on using dredged sediments, taken from the bottoms of canals or by removing spoil banks, for restoration efforts.
It is recommended that all dredged material from channel maintenance work should be used for wetland creation and restoration. Sediment from spoil banks would be used to plug many of the abandoned canals along the coast, which would also provide hydrologic restoration of freshwater flow across the affected marshes.
Looking back, moving forward
As we review these early restoration plans, it becomes clear that using water and sediment from the Mississippi River to restore Louisiana’s coastal wetlands is not a new idea. Diversions have long been a key component in coastal restoration planning, though they are only one of the suite of tools we can use.
Restoration planning has spanned more than four decades in Louisiana, but it is only in the last two that consistent funding became available. Check out our next post for more on funded restoration programs in Louisiana.No Comments
By Steve Cochran, Director, Mississippi River Delta Restoration Program, Environmental Defense Fund
Ten years ago, just after Hurricane Katrina, I was asked to talk to Environmental Defense Fund’s board about the place where I grew up, the New Orleans area that had been hit so hard.
I remember two things about that discussion. One was my voice breaking unexpectedly (and embarrassingly) as we talked through pictures of the Katrina aftermath and came across places I intimately knew.
As an adult, I had developed a love/hate relationship with my home – loving the beauty, the people, the community and the culture, but frustrated by what I saw as the general tolerance of mediocrity and corrupt politics that limited its possibilities. That frustration had pushed the love down, and I had moved away. But there it was again. Sometimes you don’t know how much you care.
The second thing I remember was saying that the Katrina response was a deep test of our governments – local, state and national. As we know now, in that moment, it was a test they failed. But fast forward to July 2, 2015, the day a global settlement was announced in the Deepwater Horizon oil spill case. It was a day when governments rose to the occasion. The result was literally the largest environmental settlement in U.S. history.
The BP Settlement and Louisiana Coastal Restoration
Under the agreement, Louisiana will receive more than a third of the money – $6.8 billion of the $18.7 billion, and $5.8 billion of that is specifically targeted to restoration. The overall restoration total for Louisiana will likely be just under $8 billion, including early restoration dollars and criminal settlements.
These are significant resources at a critical time. Land loss across the coast of Louisiana, exacerbated by the spill, continues at a fearful rate. But we are making progress against that loss, and with the solid state commitment that now exists, and effective plans in place, these resources will allow us to battle back in earnest, with a clear-eyed view toward success.
In particular, the state plans to re-engage the enormous power of the Mississippi River and its sediment through a series of sediment diversions – using the natural land-building capacity of the river by reconnecting it to the delta it originally built. This science-based, innovative approach is the critical piece in our ability to provide solutions at a scale that can match the challenges in the Mississippi River Delta – now the largest restoration effort under way in the world.
Rebuilding Our Coast to Protect Our Communities
About a month after the spill, I was allowed to sit in on a tribal council of the indigenous United Houma Nation. As the oil continued to pour into the Gulf of Mexico, which it would do for another two months, I listened and watched as a man described, through a quiet voice and uncontrolled tears, how he had always looked to the waters of the Gulf and drawn confidence, knowing he could always provide for his family by accepting its gifts. But now all he could feel was fundamental fear.
Money can’t replace that kind of loss any more than it can bring back the 11 loved ones who lost their lives in the accident.
But we must do what we can – and in that context, the BP settlement is a tremendous step forward, because we can restore the Mississippi River Delta, so it can protect this area in the future.
Details matter, of course, and details remain to be decided as the Agreement in Principle is turned into a consent decree. We need to remain involved and vigilant. But it does seem clear that this agreement combines avoiding years of litigation with levels of funding that can truly make a difference.
With these resources, we can go to work to make sure that the largest environmental settlement in our nation’s history also becomes the most meaningful settlement in a place that, well, I love.