Louisiana Coastal Erosion

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Louisiana Coastal Erosion
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The problem

• LA contains approximately 40 of the nation's
  wetlands and experiences 80 of the nation's
  coastal wetland loss.
• LA is losing 25 to 35 square miles of wetland per
  year and the highest rates are occurring in the
  Barataria and Terrebonne basins at 10 and 11
  square miles per year.
• At current land loss rates, an area the size of
  Rhode Island will be gone by 2050.

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• With 500 million tons of waterborne cargo passing
  through Louisiana's system of deep-draft ports
  and navigational channels, Louisiana ranks first
  in the nation in total shipping tonnage.- If
  present land loss rates continue, more than 155
  miles of waterways and several of the ports will
  be exposed to open water within 50 years.
• LA's commercial fisheries are the most bountiful
  of the lower 48 states, providing 25 - 35 of
  the nation's total catch. LA is first in the
  annual harvest of oysters, shrimp, crabs
  crawfish, red snapper, wild catfish, sea trout
  and mullet.- By 2050, the annual loss of
  commercial fisheries will be nearly 550 million.
  For recreational fisheries, the total loss will
  be close to 200 million a year.

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Problem (continued)

• Wetlands and barrier islands provide a protection
  barrier from strong winds and hurricanes every
  2.7 miles of wetlands absorbs one foot of storm
  surge.
• Data from past hurricanes indicates that the loss
  of every one-mile strip of wetlands along the
  coast, results in an estimated 5,752,816 average
  annual increase in property damage.
• Between 60 and 70 of LA's population lives
  within 50 miles of the coast.
• Infrastructure along coastal LA is estimated at
  150 billion.

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Economic Impacts to LA and the Nation

• LA's wetland loss could cost the nation 36.6
  billion from lost public use value over the next
  50 years.
• 18 of U.S. Oil Production 24 of US natural gas
  production originates, is transported through, or
  is processed in LA coastal wetlands. - One
  fourth of our nation's energy supply depends on
  the support facilities in South Louisiana.- LA's
  oil and natural gas industries have a value
  exceeding 16 billion a year.
• Over 20,000 miles of pipelines are located in
  federal offshore lands and thousands more
  inland.- Wetlands protect pipelines from waves
  and insure that the lines stay buried in place.-
  When pipelines are exposed to more waves and
  storms, it becomes more likely that they will
  pose a threat to passing water traffic.

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How erosion occurs

• Storms often cause coastal erosion, in particular
  those storms that have high winds and big waves.
  These waves eventually wash away the soil and
  rocks that are built up in the land. What is now
  the coast in many areas, used to be miles away
  from the coast.

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• In Louisiana hurricanes are a big contributor to
  the erosion of our coast.
• When these storms come, their high winds and wave
  take out the barrier islands that protect the
  coast. After years of hurricanes all of the old
  barrier islands have disappeared and one of the
  new islands protecting our state is Grand Isle.
  Unfortunately this island may not have much time
  left.

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A COMMON KNOW FACT

• No matter what,beaches suffer from a natural
  retreat in its shoreline. This is not what makes
  erosion a problem is human made stuctures. When a
  person builds a structure on the shoreline it
  interrupts the natural process that a beach goes
  through.

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A Kick In The Groin

• Property owners put up rock walls along the shore
  called a groin. This at the time was a simple
  solution to progressing erosion . It worked by
  slowing the currents down and gathering sand on
  the up drift side of the wall. But it was soon
  discovered that these structures helped the
  property owners and took away from the beaches.

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Solution

• Already in effect are the piles of rock often
  called jetties that reduce that break down the
  waves before they reach the beach, this had saved
  a lot of the beach and Grand Isle and it is
  possible that itwould do the same in other areas.

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Solution (continued)

• A possible solution is that all areas with
  beaches make a setback point. This is the point
  where the shoreline is estimated to be in 100
  years. This would prevent building structures too
  close to the beach.

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Breakwaters

• Another simple and affective solution is building
  offshore breakwater structures that will reduce
  the wave energy before it reaches inland,
  therefore reducing the amount of impact that a
  wave has on the inland. This will decrease the
  amount of land lost.

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Our Solution

• Louisianas coastal erosion is caused by the
  diversion of the Mississippi river. It is a
  known fact that all of our land was built up by
  sediment that flowed down the Mississippi. If we
  were to diverge the Mississippi back to its
  normal route it is possible that it would build
  our lands back up.

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• http//www.restoreorretreat.org/coastal_erosion.ht
  ml
• http//www.cclockwood.com/stockimages/coastalerosi
  on.htm
• http//marine.usgs.gov/fact-sheets/LAwetlands/lawe
  tlands.html
• http//www.seafriends.org.nz/enviro/soil/erosion.h
  tm
• http//thejump.net/erosion/LaErosion.htmjump2