Archive for Reports
By Ezra Boyd, PhD, Disastermap.net, LLC
The Hurricane Surge Risk Reduction System
As we approach the 10th anniversary of Hurricane Katrina and the associated levee failures, the people of the Greater New Orleans (GNO) region face constant reminders that our safety and viability depend on a complex system made of numerous elements that together mitigate risks from hurricane induced tidal floods. The near constant construction of levees, pumps and floodgates over the last decade provides the most visible evidence of this system. Together, these components are termed the structural lines of defense. In addition, work on other important, but less visible, components have also reduced our flood risk. Broadly speaking, the other two major components are the coastal lines of defense and the community lines of defense. Together, these three components comprise the Multiple Lines of Defense Strategy for Sustaining Coastal Louisiana (MLODS).
Beyond a list of 12 separate lines of defense (see figure below), MLODS represents a system that allows us to use the professional tools and standards of systems engineering to assess the current status of storm surge risk reduction. Within the field of systems engineering, a system is defined as: “an integrated set of elements, segments and/or subsystems that accomplish a defined objective.” The 12 lines of defense make up the elements of the system, and systems engineering helps us figure out if they function in an integrated fashion to accomplish the objective of managing storm surge risk.
A recent report from the Lake Pontchartrain Basin Foundation, called “A Systems Engineering Based Assessment of The Greater New Orleans Hurricane Surge Defense System Using the Multiple Lines-of-Defense Framework,” provides a detailed assessment of the current system of levees, pumps, gates, coastal landscape features and community resilience steps that the region depends upon to manage storm surge flooding risk.
System Interactions and Factors of Concern
Once the Hurricane Surge Defense System (HSDS) has been specified as a system, the tools of systems engineering then allow us to identify system interactions that create major factors of concern. A system interaction refers to when the performance of one system element is impacted by the other elements, while a factor of concern is an element or interaction between elements that could potentially reduce the system performance. The report identified and described a number of system interactions and factors of concern. Two of the major concerns are with the Foot of the Twin Spans bridge and the IHNC/GIWW navigation canal (shown here). Both result from interactions between systems elements that affect evacuation effectiveness.
I-10 East Evacuation Route & Chandeleur Islands
Interstate 10 is a major evacuation route. During peak evacuation, an estimated 2,000 vehicles per hour utilize its eastbound lanes to escape GNO. These eastbound lanes cross Lake Pontchartrain on the edge of New Orleans. Since Hurricane Katrina, the bridge, locally known as the “Twin Spans”, has been rebuilt in an $800 million project that raised the bridge to 30 feet above sea level. Not far from the bridge is the rebuilt levee system that provides perimeter protection for GNO. Between the levee and foot of the bridge is an approximately 1 mile section of interstate that is at ground level and outside the levee system. Most of this section of highway is 7 – 8 feet above sea level. However, just before the foot of the bridge, atop of narrow peninsula that has experienced landloss on all three sides, the highway dips to around 6.7 feet above sea level. This low, unprotected section of a major evacuation route is prone to flooding early during storm surge events, thus blocking any further evacuation.
The Chandeleur Islands, a rapidly eroding barrier island chain, are located some 60 miles from the foot of the Twin Spans bridge. Yet, how they perform as a coastal line of defense affects the performance of the I-10 East evacuation route. Hydrological studies have determined that the elevation and integrity of the Chandeleurs influences the timing and height of the peak surge, with the surge peaking 1.5 feet higher and 1 hour sooner if the islands continue to erode. Exemplifying the concept of system interactions, the Chandeleur’s ability to mitigate storm surge impacts the available window of time to evacuate people using the eastbound I-10.
IHNC/GIWW Closure Operations, Vessel Evacuation, and Vehicular Evacuation
The Inner Harbor Navigation Canal (IHNC) and Gulf Intracoastal Watery (GIWW) are two manmade navigation canals within the eastern half of GNO. During Hurricane Katrina, they were major conveyance pathways for storm surge and also the location of numerous levee breeches. Since Hurricane Katrina, the area has been subject to major levee upgrades along with newly constructed floodwalls and floodgates. While these structural improvements provide a potentially much improved level of protection, the gates in particular create a new set of concerns related to system behavior. They also provide another example of asystem interaction that also affects evacuation effectiveness.
Simply put, closing the gates in anticipation of a tropical system is a complicated procedure that must be coordinated with navigational interests, railroads, and the Port of New Orleans. Most navigational vessels are required to evacuate the IHNC/GIWW before a hurricane. This in-turn requires that the vessels pass under a number of drawbridges. Since the drawbridges must be opened to let vessels pass, they then hinder vehicular evacuation of the general population. Here the operations of these structural components (the flood gates along these two canals) impact the performance of the evacuation component, another example of a system interaction that creates a major factor of concern.
These are just two of many factors of concern with the current HSDS. Our report documents others, some small and others major. Maintenance, long term funding, coordination, and public risk communication were the major themes uncovered in our study. Because it is important for the public and policymakers to understand the true level of protection, LPBF continues to build on the momentum create by this report. As step toward addressing some of the issues identified in the report, we have recently launched the Pontchartrain-Maurepas Surge Consortium to facilitate regional collaboration between levees boards, floodplains managers, coastal scientists, and others engaged in storm surge management and risk reduction.
The report, along with LPBF’s continuing efforts at implementing MLODS for coastal flood protection, has been funded by the Kresge Foundation.
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By John Lopez, Ph.D., Coastal Sustainability Program Director, Lake Pontchartrain Basin Foundation
The Lake Pontchartain Basin Foundation (LPBF) is releasing a report describing the methodology of its Hydrocoast Maps program, a research effort that began in 2012 and monitors water flow, salinity and other factors to better understand the Mississippi River estuary in the Pontchartrain Basin.
What are the Hydrocoast Maps?
The Hydrocoast Maps monitor the distribution of salinity, changes in water quality, and other pertinent information across the Pontchartrain Basin to provide an ongoing, relevant and accurate assessment of basin conditions. LPBF produces a biweekly map series that displays information on salinity, freshwater discharge, water quality, impairments, fisheries activity and a variety of estuarine-related information.
The Hydrocoast Maps provide a snapshot of the condition of the estuary, such as the distribution of saline to fresh water and other relevant factors. LPBF’s goal is for the maps to be useful to a diverse audience – including the general public, but more specifically commercial and recreational fishers, state and federal agency personnel making restoration decisions, scientists and academics.
The biweekly Hydrocoast Map products, and what they analyze, include:
- Salinity Map – isohalines (lines on maps connecting points of equal salinity) and freshwater inflows
- Biological Map – fisheries fleets and closures
- Habitat Map – wetland classification and soil salinity
- Water Quality Map – water quality impairments and fecal coliform counts
- Weather Map – cumulative rainfall, wind and tide data
Current and archived Hydrocoast Maps can be found here.
The Mississippi River Estuary
On the Louisiana coast, fresh water from rainfall and rivers flows seaward and mixes with salt water from the Gulf of Mexico, resulting in a coastal zone called an estuary. This estuarine system also coincides with the extensive deltaic (wetland) plain of the Mississippi River and gives rise to Louisiana’s valuable and productive “working coast.” There are many factors that affect this estuary, such as pollution, fisheries, hydrologic alterations, wetland loss and freshwater inflows. These influences are dynamic and the estuary is shifting daily, but it is also undergoing long-term changes. For example, since 1932 these wetlands have been converting to open water at an unnatural and alarming rate, giving rise to Louisiana’s coastal wetland crisis.
Understanding all of these natural and manmade influences on the estuary is important for local recreational and commercial fisheries, as well as for restoration scientists who may gain a deeper understanding of how the estuary functions and its trajectory of change. Change is inevitable, but we should use the best available data to work with the deltaic system and bring about comprehensive restoration of the Mississippi River DeltaNo Comments
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NOAA Study Confirms BP Oil Spill Led to Dolphin Deaths in Northern Gulf of Mexico
Leading Conservation Groups Call on BP to Accept Responsibility for Continued Environmental Damage
(New Orleans, LA—May 20, 2015) Today, the National Oceanic and Atmospheric Administration (NOAA) released a peer-reviewed study confirming that the 2010 Gulf oil disaster contributed to an increase in dolphin deaths in the northern Gulf of Mexico. Examining dolphins, including those in Barataria Bay, La. – an area hit particularly hard with heavy oil in 2010 – scientists found that contaminants from petroleum in BP oil caused lung and adrenal lesions that led to death in these dolphins.
In response, national and local conservation groups working on Mississippi River Delta and Gulf Coast restoration, including Environmental Defense Fund, National Audubon Society, National Wildlife Federation and the Lake Pontchartrain Basin Foundation, issued the following statement:
“BP has spent millions of dollars trying to dodge responsibility and convince the American public that wildlife and habitat in the Gulf were minimally impacted by its hundreds of millions of gallons of oil spilled in 2010. Just two months ago, BP marked the fifth anniversary of the Gulf oil disaster by releasing a report claiming the Gulf had largely recovered from the spill.
“Despite BP’s best claims, this new NOAA study definitively links the increased dolphin deaths in Barataria Bay with the 2010 Gulf oil disaster and is yet another example of the extensive and destructive impact that BP’s oil unleashed on the people, wildlife and environment of the Gulf. Additional scientific research conducted through the Natural Resource Damage Assessment indicates that dolphins – a top predator – are experiencing impacts from BP’s oil and are still dying at higher than normal rates due to oil exposure in the Gulf ecosystem.
“Last fall, BP was found to be grossly negligent for its actions in the Gulf oil disaster. This study is a stark reminder that the oil is still in the Gulf, it’s still causing sickness and death in some species and it’s still affecting the entire ecosystem. It’s time for BP to stop denying the true impacts of the spill and accept responsibility for its actions, so that meaningful restoration can proceed.”
Since the BP oil disaster five years ago, ongoing findings deliver truths omitted by BP’s ads: the oil disaster’s negative effects are increasingly clear, present and far from resolved.
A recent infographic depicts ongoing impacts of the Gulf oil disaster five years later. And over the past year alone, new scientific research has surfaced:
- A 2014 study found evidence of a 1,250-square-mile area of oil contamination on the ocean floor around the Macondo wellhead in deep Gulf sediments.
- A previous NOAA study found a large number of dead dolphins in heavily oiled places, including Barataria Bay, La.
- Recent studies estimate 1,000,000 birds died as a result of being exposed to BP oil.
- Modeling for a recent stock assessment projected that between 20,000 and 60,000 Kemp’s ridley sea turtles died in 2010 as a result of the spill.
- A 2014 study found concentrations of PAH (polycyclic aromatic hydrocarbon) – which can cause harmful effects in many birds, fish and wildlife – in Barataria and Terrebonne marshes, which may persist for decades.
- A 2012 study found that oiled marshes in Barataria Bay eroded at double the rate of non-oiled marshes.
- A recent survey found that 70 percent of Americans believe BP should pay maximum fines under the Clean Water Act for its role in the 2010 Gulf oil spill.
This post has been cross-posted from an article originally published on the National Audubon Society’s website
By: Melanie Driscoll, Director of Bird Conservation, Gulf Coast Conservation/Mississippi Flyway, Erik Johnson, Director of Bird Conservation, Audubon Louisiana
A BP-authored report claiming that the Gulf has recovered is inaccurate and insulting—here’s why.
Nearly five years after the largest accidental marine oil spill in U.S. history, BP is doing its best to convince the public that the 4.9 million barrels of oil that leaked into the Gulf of Mexico have done no lasting damage. That’s the message found in The Gulf of Mexico Environmental Recovery and Restoration report the company released three weeks ago.
Based on what the report does present, it’s obvious that BP chose to ignore recent research that shows the ongoing impact of the oil spill, particularly on birds (pp 15-17 of report). That BP ignores peer-reviewed science is nothing new—they have been denying culpability and the validity of peer-reviewed, published research since the spill itself. Meanwhile, their own conclusions lack peer-review and they have not released their methodology. Because of this lack of transparency, BP has made claims that are impossible to refute or verify.
One of the government agencies responsible for monitoring the Gulf health following the oil spill—the NOAA Damage Assessment, Remediation, and Restoration Program—is expected to hold itself to a high standard of independent scientific peer-review as it completes its Natural Resource Damage Assessment (NRDA). While we await the NRDA studies to be completed and released, BP has flaunted such professional standards in its allusions to NRDA findings that cannot be verified at this stage. The trustees of NRDA themselves called BP’s recent report “inappropriate as well as premature.”
Along with others in the scientific community, the National Audubon Society rejects BP’s claims. While their report leaves much to criticize, here are its five main flaws:
- Their conclusions are not credible given lack of peer-review, questionable methodology and premature conclusions.
They claim “search teams likely found 97 percent of large birds and 78 percent of small birds.” These numbers are inconceivable to any researcher or birder who has looked for birds on a beach. It stands to reason that a detection rate of 97 percent as claimed by BP is unlikely, even for living and mobile birds; their estimate seems grossly optimistic compared to detection rates published widely in the scientific literature. In addition, BP compared their estimate of searcher efficiency for carcasses placed on beaches to the searcher efficiency across sandy beach, rocky beach, and marsh habitats. Detection rates are known to vary widely based on factors such as carcass coloration and habitat, and the actual searches in the Deepwater Horizon disaster occurred across marsh, mangrove, rocky beach, and sandy beach habitats. Attacking a single parameter from a complex study, and doing so using an apples-to-oranges comparison, is disingenuous and misleading.
- The Gulf of Mexico ecosystem has not returned to a pre-oil spill “baseline condition”.
First of all, the oil is not gone. Significant deposits (up to 230,000 barrels) of oil have been discovered in the sediment on the Gulf floor. This oil regularly washes ashore during storms, re-oiling marshes and beaches. In October 2014, researchers discovered a 1,250-square-mile “bathtub ring” of oil on the Gulf floor–equivalent to the size of Rhode Island. Indeed, as the BP report was released a 22,000-pound tar mat was being removed from East Grand Terre Island in Barataria Bay, LA.
BP’s conclusions are incredibly premature. With lagged effects, trophic cascades, food web effects, and repeated re-oiling of the coast, we could be seeing surprises and environmental effects for years to come on birds and on the entire ecosystem.
Erosion is forever. Land and crucial habitats have disappeared. It’s impossible to return to a “baseline” when the land that composed that baseline and is crucial to coastal bird populations has disappeared. Studies show that marsh that was heavily oiled was undercut and eroded back, creating ragged marsh edges that were unoiled or lightly oiled. The scientists have then seen a wave of erosion of these unoiled or lightly oiled marsh, as waves reshape the ragged marsh edge to create a new, smoother edge. Not only has much of the heavily oiled marsh eroded, but marsh that was less damaged has followed.
- Damage to birds from the BP oil spill is evident and has been well documented, contrary to what BP reports.
In the 95 days following the oil spill, conservative estimates are that hundreds of thousands to more than a million birds died.
This acute damage does not take into account the molecular, cellular, reproductive, and developmental damage that may accumulate in birds for years to come. That is significant, it is long-term, and it matters.
Birds exposed to oil during their early development may accumulate damage that causes failed reproduction. Additionally, many long-lived species like pelicans, terns, and egrets do not breed until their second, third, or fourth year of life, meaning the young exposed to oil early in their lives hadn’t started breeding in 2011, making BP’s conclusions based on 2011 information premature.
- More studies are needed to understand the ongoing and long-term effects on bird populations.
In other species, lagged and trophic level effects have resulted in increasing effects from oil being detected over time since the disaster. Very few studies on bird productivity have been published that looked beyond the 2010-2011 nesting season. More studies are needed to draw broad conclusions.
Scientifically, the most reliable way to study productivity is to compare productivity of birds exposed to oil and not exposed to oil within the same season. The only study of which we are aware that has used this reliable methodology is a study of the Seaside Sparrow, which showed reduced nest success for sparrows on oiled sites in 2012 and 2013.
- BP’s use of Audubon’s Christmas Bird Count (CBC) data is flawed and their summaries of other data are incomplete and misleading.
BP misused CBC data to obscure potential impacts. It’s likely they used data from well outside the impacted areas. Particularly, Sandwich Terns and Northern Gannets are not counted by CBC participants 10-100 times more than Piping Plovers in the impacted areas. The numbers they used for Red Knots appear to include the entire rufa subspecies, which mainly winters in the Tierra del Fuego region in southern Argentina and the Maranhão region of northeastern Brazil. It is difficult to tell how CBC data were used, but it is clear from the relative abundance of some species that data from outside the Gulf were included in analyses. Using broader data from other regions could mask any local and regional changes in populations due to the oil spill. Without describing their methods, it is apparent that BP’s report represents a misuse of Audubon’s publicly available data.
BP reported oiling rates from long after the oil well was capped, resulting in oiling rates that appear to be very low: In its report, BP cites data saying “researchers saw no visible oil in 99 percent of the roughly 500,000 live bird observations from May 2010 to March 2011.” A study following the Deepwater Horizon spill showed that 8.6 percent of captured shorebirds showed evidence of oiling, indicating that BP’s observational evidence may have underestimated exposure by as much as an order of magnitude.
BP selected a study that appeared to show no effects on birds to highlight a success that is likely just a lack of use of the oiled region: In BP’s reference to the Northern Gannet publication, researchers in this paper used light-level geolocators to determine wintering locations of Northern Gannets. Digging into the details of the paper, it is clear that only a small sample of the researcher’s birds wintered in the Gulf of Mexico (8 birds in their study) and that the Gulf birds foraged in areas primarily >100 miles away from the spill site, i.e., well outside of area of the most devastating impacts. Thus it may be no surprise that these few birds did not show elevated polycyclic aromatic hydrocarbon (harmful chemicals from oil) levels as they were not in the spill zone. The U.S. Fish and Wildlife Service’s published account of bird deaths following the spill paints a different picture—Northern Gannets were one of the most frequently encountered dead bird after the spill.
BP incorrectly concluded from a published study that researchers did not find evidence that variations in age classes of Brown Pelicans on Louisiana barrier islands were related to the oil spill. However, the paper specifically states “…additional research is required to evaluate potential long-term population trends.” Also, “Care should be taken in interpretation of our result as a lack of effect [of oil] on demography because there are combinations of spill-related reductions in fecundity and age-specific mortality that could result in no changes in age structure.” One scenario that’s easy to imagine is that all age classes were reduced similarly. In short, like the authors state, there are many possible scenarios that could influence their findings.
Despite BP’s claims, we may not know the full impact of the oil spill for decades to come. Even more, we will not achieve lasting, meaningful restoration in the Gulf Coast until BP quits stalling, quits the legal and publicity campaign and actually funds full restoration.
Sign this petition telling BP to stop their delay tactics and fully fund Gulf restoration.No Comments
This was originally posted on the National Wildlife Federation's Wildlife Promise blog.
By Ryan Fikes, National Wildlife Federation
BP has just released a new report on the state of the Gulf, called Gulf of Mexico: Environmental Recovery and Restoration. The glossy report is filled with footnotes and citations, but leaves key pieces of science out.
Here are ten important things BP’s latest report strategically didn’t mention:
- Dolphins died before the spill – from freshwater
The report says: “An “unusual mortality event” (UME) involving an abnormally high number of dolphin deaths in the Gulf of Mexico began in February 2010, months before the Deepwater Horizon accident.”
What it leaves out: The deaths of a cluster of dolphins during the months before the Deepwater Horizon exploded were likely caused by extended exposure to fresh water and unusually cold weather. (Source: NOAA)
- Gulf dolphins are now very susceptible to an old disease
The report says: “NOAA has said that brucella, a bacterium that can infect animals, is “a common thread” in a number of the animals examined. Nearly one-third of the dolphins tested as of Nov. 25, 2014 were positive for brucella.”
What it leaves out: In 2011, Teri Rowles, the coordinator of NOAA’s National Marine Mammal Health and Stranding Response Program said, “Severe environmental stress, including from exposure to oil, could have reduced the animals’ ability to fight infection.”(Source: NOAA)
And in 2013, NOAA released a study showing that dolphins in heavily-oiled Barataria Bay had adrenal gland problems consistent with oil exposure that would in fact harm their ability to fight infections.(Source: Environmental Science & Technology)
- For the Kemp's ridley, anything less than an increase is a decrease
The report says: “For Kemp’s ridley sea turtles, nesting numbers the two years after the accident were above historical averages.”
What it leaves out: Up until 2009, Kemp’s ridley nests were increasing exponentially (15-19%) every year. In 2011 and 2012, the number of Kemp’s ridley nests—while essentially the same as the
numbers seen in 2009—were still below expectations. Even more troubling are the significant decreases in nests seen in 2010, 2013, and 2014. (Source: Gulf States Marine Fisheries Commission)
- Sperm whales in the Gulf have high levels of toxic metals
The report says: “While data analysis is ongoing, BP has not seen any evidence indicating that oil or dispersant compounds from the Deepwater Horizon accident have impacted the health of whales in the Gulf.”
What it leaves out: Researchers have found higher levels of DNA-damaging metals such as chromium and nickel in sperm whales in the Gulf of Mexico compared to sperm whales elsewhere in the world. (Source: Environmental Science & Technology)
And a recent study found that the two dispersants used in the Deepwater Horizon spill—Corexit 9500 and 9527—were both found to be damaging to sperm whale cells and DNA. (Source: Aquatic Toxicology)
- Oil exposure damages fish development – in many species
The report says: “A study by university and government researchers examined the overlap between spawning habitat and oiled waters and concluded that the spawning area for bluefin tuna extended much farther west than previously known and that “the proportion of spawning habitat impacted by oil was generally predicted to be small (<10%).”
What it leaves out: Estimates vary on how many larval bluefin tuna may have been exposed. One NOAA study estimated that the figure could be as high as 20 percent. (Source: NOAA)
And a recent comprehensive laboratory study found that a chemical in Deepwater Horizon oil can cause irregular heartbeats in bluefin and yellowfin tuna that can lead to heart attacks, or even death. The resulting heartbeat changes significantly altered the development of other organs. The researchers suggest that many other vertebrate species in the Gulf could have been similarly affected. (Source: Science)
- Right after the spill, red snapper and other fish had unusual lesions
The report says: “Researchers from the University of South Alabama and Dauphin Island Sea Lab in Alabama took samples of reef fish from the Alabama and western Florida Panhandle coasts from January 2010 to June 2011. They found no significant evidence of diseased fish in those populations.”
What it leaves out: In the aftermath of the spill, a number of fish caught in the Gulf between eastern Louisiana and western Florida had unusual lesions or rotting fins. Lesions were most common in bottom-dwelling species, including red snapper, and were particularly common north of the wellhead. (Source: Transactions of the American Fisheries Society)
- An unusual lack of young red snapper
The report says: “In an Auburn University study published in 2014, researchers found no evidence that the spill affected young red snapper populations on reefs off the Alabama coast.”
What it leaves out: Both 2010 and 2011 had the lowest numbers of juvenile red snapper seen in the eastern Gulf fishery since 1994. (Source: NOAA SEDAR)
- Seaside sparrows on oiled sites less likely to fledge
The report says: “Data from studies that BP conducted independently indicate that in 2011, the spill did not adversely impact bird productivity – how successful birds are at producing offspring. Brown pelicans, laughing gulls, great egrets, black skimmers, bald eagles and ospreys were studied.
What it leaves out: Preliminary data from 2012 and 2013 indicate that seaside sparrows from nests on unoiled sites were significantly more likely to fledge than those on oiled sites.. (Source: BioScience)
- Oil is still washing up on beaches
The report says: “Since some of the heavily oiled areas were last surveyed a year or two earlier, NRDA teams resurveyed the areas in 2014 and determined that a total of just one mile remained heavily oiled.”
What it leaves out: Recent studies of beach shoreline in Alabama suggest that tar balls are likely to continue washing up for years to come on Gulf Coast beaches, and could pose a risk to organisms living on or near those beaches. (Source: Science of the Total Environment)
- Oil remains in Louisiana's coastal marshes
The report says: “A 2012 University of Florida study that measured the rate of marsh erosion in a limited geographic area in Louisiana showed that erosion rates returned to normal 18 months after the spill and that its impact was generally limited to the edge of the marshes.”
What it leaves out: In May 2013, three years after the spill, more than 80 miles of marsh shoreline in Louisiana remained visibly oiled. The long-term effects of the oiling of Gulf marshes are still unclear and may take decades to unfold. (Source: International Oil Spill Conference)
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
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Emily Guidry Schatzel, National Wildlife Federation, 225.253.9781, email@example.com
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Conservation Groups Release Restoration Solutions for Mississippi River Delta
New report recommends a series of science-based restoration efforts to benefit coastal Louisiana
(NEW ORLEANS – December 9, 2014) Today, leading national and local conservation groups released a report outlining 19 priority projects for restoring the Mississippi River Delta following the 2010 Gulf oil disaster.
Restoring the Mississippi River Delta for People and Wildlife: Recommended Projects and Priorities was jointly authored by conservation groups working together on Mississippi River Delta restoration – Environmental Defense Fund, National Wildlife Federation, National Audubon Society, Lake Pontchartrain Basin Foundation and the Coalition to Restore Coastal Louisiana – and describes a suite of restoration projects that would collectively reverse wetlands loss and help protect New Orleans and other coastal communities from storms. The project recommendations include sediment diversions, freshwater diversions, marsh creation, barrier island reconstruction, ridge restoration, shoreline protection and hydrological modifications. The proposed project solutions can work in tandem to not only build but also sustain new wetlands along Louisiana’s coast.
The report is aimed at informing a series of decisions that will be ultimately made for funds flowing from the Gulf oil disaster, including those to be made by Gulf Coast Ecosystem Restoration Council (Council). The federal-state Council is tasked with implementing a comprehensive restoration plan to include a list of projects prioritized for their impact on the Gulf ecosystem. The Council recently released a list of projects and programs proposed for funding with oil spill penalty money.
“The Mississippi River Delta was ground zero for the Gulf oil disaster,” said David Muth, National Wildlife Federation’s director of Gulf restoration. “These project recommendations, if selected and implemented efficiently, could begin in earnest the wholesale restoration of one of the most ecologically and economically important areas in the entire country. The health of the Mississippi River Delta is a cornerstone for the health of the entire Gulf Coast. ”
“We have a once-in-a-lifetime chance to get this right and start real restoration along the Gulf Coast,” said Doug Meffert, executive director and vice president of Audubon Louisiana. “Our recommendations present a full suite of restoration solutions that work in concert, providing complementary benefits and sustaining one other. We hope the Council will select restoration projects like these, which are scientifically shown to provide the maximum benefit to the entire Gulf ecosystem.”
“By combining different types of projects in the same geographic area – for example, sediment diversions, marsh creation and barrier island restoration – we can build new land quickly and sustain it for the long term,” said Natalie Peyronnin, director of Science Policy for Environmental Defense Fund’s Mississippi River Delta Restoration Program. “This comprehensive approach to restoration is much more effective than using a band-aid approach. We must get restoration right – and get it started now – for the communities, wildlife and economies of the Gulf.”
“The oil spill affected wildlife and ecosystems across the Gulf Coast, and we need to make smart decisions about how to use this money to improve the health of the entire system,” said Muth. “We owe it to future generations to determine where this money can have the greatest impact and to focus our efforts there.”
The oil disaster sent roughly 200 million gallons of oil into the Gulf of Mexico. Louisiana’s coastline received the largest amount of oil and was suffering one of the fastest rates of wetlands loss in the world even prior to the spill. BP and the other companies responsible will ultimately pay billions of dollars in penalties and punitive damages, much of which will be allocated to the Gulf states for restoration.
Please contact Emily Guidry Schatzel, firstname.lastname@example.org, for a recording of the telepress conference.
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. Composed 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 New Orleans and Baton Rouge, Louisiana; Washington, D.C.; and around the United States. A map of the projects and descriptions are available for download at www.mississippiriverdelta.org/map.1 Comment
IPCC report examines climate change’s effects on Mississippi River Delta and strategies for adaptationAugust 5, 2014 | Posted by Delta Dispatches in Community Resiliency, Economics, Hurricanes, Job Creation, Reports
By Keenan Orfalea, Communications Intern, Environmental Defense Fund
“There are risks and costs to action. But they are far less than the long range risks of comfortable inaction.” – President John F. Kennedy
The Mississippi River Delta – one of the largest and most productive wetland ecosystems in North America – is teeming with life, and this rich bounty has supported the development of unique cultures and traditions, alongside industry. At the same time, Louisiana’s fragile coastal wetland ecosystems are facing collapse. Today, the region also faces serious threats from global climate change, combined with other manmade impacts. Climate impacts could devastate Gulf fisheries, submerge critical infrastructure like Port Fourchon and imperil cities such as New Orleans. These outcomes are not inevitable, though, if meaningful action is taken.
Coastal wetlands are the first line of defense against climate change impacts such as storm surge. Unfortunately, the Mississippi River Delta has been losing wetlands at an alarming rate as a result of unsustainable river and coastal management practices. Since 1932, Louisiana has lost nearly 1,900 square miles of land, and every hour, an area of land the size of a football field turns into open water.
While this gradual process may go unnoticed from day to day, the consequences became clear through the devastation of natural disasters such as Hurricanes Katrina and Rita. Intact coastal wetlands could have protected against the force of these storms, because they have the potential to buffer storm surge. For communities that lie behind natural wetland barriers, restoring such ecosystems will increase communities’ resiliency and ability to thrive in the face of climate change.
A recent report by the Intergovernmental Panel on Climate Change (IPCC) focused on the observed and predicted effects of climate change as well as adaptation strategies. The report found strong evidence of variation in key environmental indicators over the past two decades and predicts that this variation is likely to continue into the future, generating increasingly severe effects over time. The report also explores what can be done to confront these new challenges and protect against the most extreme impacts.
For vulnerable, low lying areas like southern Louisiana, any effective adaptation plan will have to utilize multiple strategies simultaneously. Coastal wetland restoration will be one of the most important and cost effective tools for adapting to climate change.
There are costs associated with any restoration program, but strategic investment could produce economic gains for the entire Mississippi River Delta region. According to an analysis by The Center for American Progress and Oxfam America, long-term investment in ecosystem services returned $15 in value for every $1 spent. The same study found that an average of 17 jobs were created per $1 million in spending on ecosystem services, compared to only 9 jobs created from the same investment in the offshore oil and gas industry.
Adaptive coastal planning delivers further benefits by mitigating potential losses from storm damage and sea level rise. Taken together, the gains in human safety and economic stimulus stemming from adaptive planning far exceed the costs of any coastal restoration program. Embarking on this course of action will not only ensure the long-term sustainability of the Mississippi River Delta and its communities, but it could also lay the foundations for future economic development.
Climate change is a global problem, but the earliest and most severe developments will be felt in areas that are most exposed, like the low-lying and disappearing Mississippi River Delta. While mitigating the future impacts of climate change will require an international effort, adaptation must take place on the regional and local levels. Louisiana’s most pressing threats stem from its vanishing coastline. In order to meet the challenges of the future, policymakers and citizens must take immediate action in order to reverse this land loss crisis, because comfortable inaction is not an option.No Comments
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