Louisiana Coastal Wetlands Lawyer & Attorney : Erich P. Rapp : Kean Miller Law Firm : Serving New Orleans, Baton Rouge, Shreveport, Louisiana

The situation in the Mississippi River where more sediment than ever is going into the river and less sediment than ever is reaching the coastal wetlands in Louisiana as described in the recent National Research Council report on the Mississippi River is not unique to the Mississippi River.

The problem is an international problem. On May 21, 2005, Science News Online published a report concerning river sediment entitled, Muddy Waters: More sediment is entering rivers, but less makes it to the sea. In turn, this Science news article was directly related to the publication of the scientific research paper entitled, Impact of Humans on the Flux of Terrestrial Sediment to the Global Coastal Ocean. This research article was published in the April 15, 2005 issue of Science Magazine in Volume 308 at page 376.

The conclusion of the Science news article and the research paper cited above are that humans have simultaneously increased the sediment transport by global rivers through soil erosion by approximately 2.3 billion metric tons per year, yet reduced the flux of sediment reaching the world's coasts by approximately 1.4 billion metric tons per year because of retention within reservoirs. Further over 100 billion metric tons of sediment and 1 to 3 billion metric tons of carbon are now sequestered in reservoirs constructed in the last 50 years.  Further still, coastal retreat is directly influenced by the reduction of river-supplied sediment.

The accumulation of sediment behind dams in accompanying reservoirs (particularly in the Missouri and Arkansas Rivers) as well as the accumulation of sediment behind locks in accompanying slack water navigation pools in other parts of the Mississippi River drainage system are contributing directly to the loss of coastal wetlands in Louisiana to the open sea.

Erich P Rapp.

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I have repeatedly written about the role of dams, locks and reservoirs in the Mississippi River system and their role in the loss of coastal wetlands in Louisiana. Now, I will provide some research in support of this position.

Dr. Richard H. Kessel, a professor of Geography and Anthropology at Louisiana State University, is the person that has written the most extensively on the decline of the sediment load in the Mississippi River and its role in the loss of coastal wetlands in Louisiana. His papers have included:

1. An Approximation of the Sediment Budget of the Lower Mississippi River Prior to Major Human Modification which was published in volume 17, pages 711-722 (1992) of Earth Surface Processes and Landforms.

2. The Role of the Mississippi River in Wetland Loss in Southeastern Louisiana, U.S.A. which was published in Volume 13, Number 3, pages 183-193 of Environmental Geology and Water Science.

3. The Decline in the Suspended Load of the Lower Mississippi River and its Influence on Adjacent Wetlands which was published in Volume 11, Number 3, pages 271-281 of Environmental Geology and Water Science.

4. Chapter 12 Historical Sediment Discharge Trends for the Lower Mississippi River in Volume II: Technical Narrative of the Outer Continental Shelf Study by the Mineral Management Service, study number 87-0120 which larger document is entitled Causes of Wetland Loss in the Coastal Central Gulf of Mexico.  

The gist of Dr. Kessel's research shows that the suspended sediment load in the Mississippi River as it passes through Louisiana has declined by about 80% since the 1850's. He divides the history of this decline into three periods. These periods are 1) Prior to 1900, 2) a pre-dam period until extensive dam construction began between 1930 and 1952, and 3) the post dam period since 1952. The suspended load decreased 41% before dam construction began and another 51 percent after the dams in the Missouri and Arkansas Rivers were constructed. This change has altered the balance between sediment deposit in the wetlands adjacent to the Mississippi River and the ongoing process of subsidence and global sea level rise. In the most recent period, the rate of sea level rise and subsidence exceeds the rate of sediment deposit. Thus, the coastal wetlands are being lost to open water.

Erich P. Rapp 

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Dr. J. David Rogers, Professor of Geological Engineering at the University of Missouri-Rolla will make a presentation on coastal land loss in Louisiana at the annual meeting of the Geological Society of America which is being held in Denver, Colorado from October 28 to 31, 2007. The presentation will be held on October 31st at 10:30 AM in Room 505 of the Colorado Convention Center. The presentation is entitled, Geological Factors Promoting Subsidence and Coastal Land Loss in the Mississippi River Delta and the Great Debate about what to do about it.

Erich P Rapp.

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On October 16, 2007, the National Research Council issued a press release concerning the publication of their upcoming report entitled, Mississippi River Water Quality and the Clean Water Act: Progress, Challenges and Opportunities. A pre-publication copy of the report is also available online as a .pdf file. 

Again, the National Research Council has emphasized an important theme related to coastal wetland loss in Louisiana. The report strongly suggests that the Mississippi River system including the major tributaries need to be analyzed and administered as a whole and not in parts. Decisions are often made in relation to segments of the system without regard to the impact of those decisions on other parts of the river. The report specifically mentions the lack of sufficient sediment in the Mississippi River reaching the wetlands along the river in Louisiana as an example of this management issue. Inevitably decisions made far to the north of Louisiana along the Mississippi River determine the sediment transport of the river as it reaches the wetlands in Louisiana.

The people in Louisiana and the rest of the Mississippi River basin need to remember this truth when they take action in relation to the Mississippi River.

Erich P. Rapp 

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When I have questions about basic geology, I refer to Physical Geology by Charles C. Plummer, David McGeary, and Diane H. Carlson. It is an introductory college text with great explanations for everything geology related with many pictures and diagrams. 

For example, why does flowing water transport or carry sediment? The answer is on page 28,

"In a water molecule, the two hydrogen atoms are tightly bonded to the oxygen atom. However, the shape of the molecule is asymmetrical, with the two hydrogen atoms on the same side of the atom. This means the atom is polarized, with a slight excessive positive charge at the hydrogen side of the molecule and a slight excessive negative charge at the opposite side. Because of the slight electrical attraction of water molecules, other substances are readily attached to the molecules and dissolved or carried away by water. Water has been called the universal solvent. Dirt washes out of clothing; water, in blood, carries nutrients to our muscles and transports waste to our kidneys and out of our bodies."

Of course for our purposes in this blog, streams and rivers also transport sediment.

Erich P Rapp.

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Almost all of the coastal area of Louisiana is no more than a few feet above sea level. This condition leaves many people in South Louisiana concerned about global sea level rise as well as the subsidence experienced in the Mississippi River delta region. If anyone ever doubted that the federal government and the Corps of Engineers were also quietly worried above the problem, the article on October 2, 2007 in the Los Angeles Times entitled Coastal buyout talk roils lives in Mississippi should remove all doubt.

The Corps of Engineers appears to have begun undertaking a voluntary project which looks a lot like a "pilot" project to assess the feasibility of a larger scale retreat from low lying coastal regions. Susan I. Rees of the Corps is directing a project aimed at buying out 17,000 coastal homes in Mississippi near Bay St. Louis with a proposed budget of $10 billion.  

Although the Corps states that it is not considering expansion of this buyout program, the implication for the bulk of Louisiana south of Interstate 10 is painfully clear.

Has the federal government and the Corps of Engineers quietly come to the conclusion that low lying coastal areas cannot be saved from inundation resulting from global sea level rise?  What does this mean for the coastal wetlands of Louisiana?

Erich P Rapp.

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The Upper Mississippi River contains twenty-nine (29) locks and dams creating slackwater navigational pools to allow barge navigation on the upper part of the river from north of St. Louis to Minneapolis.  Congress authorized the construction of this system of locks and dams in 1930 and the Corps of Engineers completed construction by 1940.

This navigation system is very important to the economy of Louisiana and its neighbors to the north. The original locks and dams are now out of date and need to be replaced. The new and larger system of locks and dams that are proposed are also very important to the economic interests of Louisiana and the states upstream on the Mississippi River from Louisiana. The people of Louisiana should, and I am sure do support the replacement of these locks and dams.

This construction project also brings other opportunities. The original locks and dams caused damage to the Louisiana coastal wetlands by disrupting sediment transportation in the Mississippi River. Now that the locks and dams need to be replaced, a new opportunity exists to consider the impact that the locks and dams have on coastal Louisiana. The new locks and dams could be designed, constructed and operated to improve sediment transport in the Mississippi River toward the coastal wetlands of Louisiana. Although dams are potentially damaging to coastal regions, dams and locks can be designed, built and managed to minimize their impact on the coastal region. One book that describes how this can be done is called Reservoir Sedimentation Handbook: Design and Management of Dams, Reservoirs, and Watersheds for Sustainable Use by Gregory L. Morris and Jiahua Fan. 

The National Research Council of the National Academies prepared a Review of the U.S. Army Corps of Engineers Restructured Upper Mississippi-Illinois River Waterway Feasibility Study in 2004. On page 27 of this review, the National Research Council made its case for better ecology in the Mississippi River through "Integrated Systems Planning." Issues related to the Louisiana coastal environment were discussed. The report stated:

"A broad holistic prospective is also necessary because of the significant implication of Mississippi River water quality and sediment transport for downstream regions in and along the Gulf of Mexico. The Corps should thus, to the maximum extent feasible, consider factors such as water quality, flood damage reduction, and sediment transport in order to reflect a more holistic approach to dealing with the diverse management issues in the UMR-IWW."

One of the keys to the long term survival and restoration of the coastal wetlands in Louisiana is Mississippi River sediment transport. This issue is often ignored when water resource planning is done upstream from Louisiana. Such is the case here.

The Corps contends that they are not authorized by Congress to consider the impact of the existing Upper Mississippi-Illinois River Waterway locks on the coastal wetlands of Louisiana when planning the construction of new larger locks. As a result, the Corps has not considered the impact of this construction project on coastal Louisiana. Not only do a number of federal statutes allow consideration of the Louisiana coastal wetlands in this situation, but the consideration is arguably mandated.

The federal government as well as the government and people of Louisiana should consider the impact on coastal Louisiana of projects undertaken in the Mississippi River drainage basin upstream from Louisiana. The health of the Louisiana coastal wetlands requires it.

Erich P. Rapp

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