Effects of Hurricane
Katrina on Local
Environment
By: Bethany Olson, Dan Wieland, Joe Zhiss,
and Victoria Nicholas
Group 5
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Abstract
The purpose of this study was to acquire knowledge on the effects Hurricane Katrina had
on the environment, the results are devastating. Wetlands were wiped out, habitats were greatly
altered, and forested lands became homes to invasive species and decomposing timber. Katrina
not only devastated terrestrial ecosystems but aquatic ecosystems as well. The impact that
Katrina had on Lake Pontchartrain was immense as it became the primary dumping area for
flood waters that contained 6.5 million gallons of oil. The amount of salinity added to the lake’s
ecosystem also affected wildlife and aquatic species. In the Gulf of Mexico, toxic substances,
floodwaters, organic material, and excess nutrients impacted fisheries by contaminating water
sediments, killing fish, and destroying shrimp and oyster production. We are still recovering
from this natural disaster to this day. The recovery process has been the largest natural disaster
recovery operation in the history of the United States. The cleanup process has raised a variety of
environmental concerns regarding debris, waste management, and contaminated floodwaters.
Introduction
Hurricane Katrina is one of the most horrific and deadly natural disasters in United States
history. The size, wind speed, and location of the storm made it one of the top five deadliest
hurricanes in United States history. The damages it caused reached in the billions of dollars and
ruined millions of lives. With the storm reaching Category 5 status at its peak, this storm caused
irreparable damage to the economy, the ecosystem and the life of the people who lived in the
way of its path.
Hurricane Katrina formed on August 23rd of 2005 as a result of an interaction of a
tropical wave and the remains of Tropical Depression Ten, a tropical cyclone formed ten days
earlier. At this time, however, it was only considered a tropical cyclone itself known as Tropical
Depression Twelve. It was given its tropical storm status on August 24th and was given the
name Katrina. On August 25th it was given its hurricane status, only 2 hours before reaching
land. The hurricane quickly turned from a Category 3 hurricane to a Category 5 after entering
the Gulf. The reason it rapidly intensified was because of the unusually warm water of the Loop
current which increased the wind speeds. The hurricane reached its peak on August 28th with a
maximum wind speed of 175 mph. It was the fourth most intense Atlantic hurricane recorded at
the time. The hurricane continued to slowly move inland reaching as far as Meridian,
Mississippi before weakening and losing its hurricane status. The last remnants of the storm
were distinguishable in the eastern Great Lakes on August 31st.
When it was discovered where the hurricane was headed and what damage it would do,
the United States Coast Guard began prepositioning resources throughout the Gulf coast. Rescue
crews were launched all throughout the coast, from Texas to Florida. A state of emergency was
declared by President George W. Bush in selected regions of Louisiana, Alabama, and
Mississippi on August 27th. During this time, there was expressed concern that Katrina might
push its storm surge over the city’s levees and floodwalls. The flood waters would eventually
surge over the levees. It was during this time that President Bush encouraged the evacuation of
New Orleans because it lies below sea level. On August 28th, the mandatory evacuation of New
Orleans was ordered by President Bush and Louisiana Governor Blanco.
The damages caused by Hurricane Katrina were devastating. With over 90,000 square
miles of land being affected by the hurricane, it is no wonder that this natural disaster was one of
the biggest in United States history. The major flooding from the hurricane in New Orleans was
primarily due to the failure of the levees. For the most part, failure of the levees was due to
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system design flaws. Apparently, the designers, builders, and maintenance people did not devote
enough time or attention to the levees in the region. Over one million non-farm jobs existed in
the area before the hurricane with 600,000 of them in New Orleans, but after the disaster these
people were left jobless. It is estimated that 80% of the city of New Orleans was under water at
some point during the hurricane, up to 20 feet deep in places. The worst part of the storm was
how deadly it was. The final death toll was 1,836 with the majority of the deaths coming from
the state of Louisiana.
The damages done to the economy were extremely high as well. An estimated $75
billion in physical damages was done to the area making it the most costly hurricane in history.
However, it is estimated that the economic damages from the hurricane will exceed more than
$150 billion in Louisiana and Mississippi. The interruption of the oil supply was one of the
biggest damages to the economy. 30 oil platforms were destroyed or damaged during hurricane
Katrina.
Rationale & Objectives
After learning about how widespread and devastating the effects of Hurricane Katrina
were, we wondered what kind of impact the hurricane had on the environment. We were curious
to find out how the natural disaster affected various ecosystems. We also wanted to learn about
the recovery process as well as the environmental issues associated with the cleanup. The goal of
our research is to gain insights into the impact that Hurricane Katrina had on different aspects of
the environment. We will specifically focus on the impacts on terrestrial ecosystems, aquatic
ecosystems, and the recovery process. We also hope that by studying this natural disaster, we
will be better prepared for handling future natural disasters.
Major Impacts on Terrestrial Ecosystems
It is no secret the major effects hurricane Katrina had on the homes and people it struck,
but what many people forget to look at is the damaging effects it had on the local environment.
Some of the affected areas were coastal wetlands, wildlife refuges, and forested lands. Hurricane
Katrina, a hurricane that is known to be one of the deadliest and most destructive hurricanes to
date, devastated each of these things.
First, the destruction of the coastal wetlands was devastating. The strong winds from
hurricane Katrina altered several barrier islands off the coast of Louisiana. These islands served
as a type of bumper from things like hurricanes and storm surges. Furthermore, they were an
important wildlife habitat. There was a significant amount of land loss as a result of hurricane
Katrina as well as damaged seagrass beds. Seagrass beds are a type of submerged aquatic
vegetation. They have evolved from terrestrial plants and have become specialized to live in the
marine environment. The loss of seagrass beds has affected aquatic life, which use these habitats
for spawning, nesting, and feeding. Species that depend on seagrass beds include marine
mammals, turtles, and fish, as well as migratory species such as redhead ducks.
Next, wildlife refuges were severely impacted. Katrina damaged a total of 16 wildlife
refuges and altered the habitat for at least three endangered species. All 16 refuges in the area,
totaling approximately 365,000 acres, have been closed. There was significant damage reported
in Louisiana and half of the refuges 18,000 acres were wiped out. Some believe that the habitat
alterations in the refuges will cause waterfowl and other avian species to search for other nesting
sites. The damage in these wildlife refuges is widespread, including the loss of wetlands, large
areas of tree blow downs, and salt-water intrusion. There also was entry of toxic waters and
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excess nutrients into Lake Pontchartrain, which also may affect the endangered populations of
manatees.
Finally, the hurricane caused damage to forested lands. The Gulf Coast states are
significantly forested and are major producers of lumber and plywood. An estimated 19 billion
board feet of timber was damaged over 5 million acres in Mississippi, an estimated $5 billion
loss in potential timber revenue. The forested area damaged represents 30% of the total
timberland in the affected region, 90% of which occurred on on-federal lands. An estimated
80% of the damage happened in Mississippi. There was an estimate of 1.3 million acres of
forestland damaged in the state of Mississippi.
In addition to the damages to wildlife habitat and other environmental services from the
loss of forest cover, the dead and damaged trees can become hazardous fuels for wildfire as well
as a haven for forest insects and diseases. For example, in Mississippi, the amount of tree debris
available for fueling a wildfire is an estimated 20-30 times the normal levels. There are efforts
being made to try and remove the fallen timber and salvage the useable timber. Some argue that
the period for salvaging timber is declining due to warm and moist conditions that promote wood
decomposition. Fallen timber can promote infestations as well as provide favorable conditions
for the establishment of invasive species. Some damaging insect species can thrive on fallen
trees and then harm living things. Forested lands exposed to increased levels of sunlight caused
by fallen trees are susceptible to invasive non-native species. The effects of Katrina were not
only on the terrestrial ecosystems, but the aquatic ecosystems as well.
Major Impacts on Aquatic Ecosystems
One of the major consequences of Hurricane Katrina was the impact it had on Lake
Pontchartrain. This water body is about 630 square miles and is connected to the Gulf of Mexico
through Lake Borgne. Before Hurricane Katrina, Lake Pontchartrain was a major dumping
ground for many sources of pollution such as fertilizers, animal wastes, oil and gas spills,
discharge from treatment plants, and storm water runoff. After the hurricane, the lake was also
the primary dumping area for the flood waters that flowed throughout New Orleans for three
weeks. These flood waters contained harmful wastes such as bacteria, raw sewage, pesticides,
heavy metals, etc. Some reports estimate that Hurricane Katrina caused the release of 6.5 million
gallons of oil from places like sewage treatment centers, storage tanks, and industrial chemical
stores. Lake Pontchartrain was also affected by the amount of saltwater brought into its
ecosystem, killing many of the lake’s wildlife. Although it is evident that Hurricane Katrina had
huge impacts on the lake’s ecosystem and its aquatic species, scientists are still trying to
determine the exact numbers.
To help answer some of the questions we have about the disruptive effects that Katrina
had on Lake Pontchartrain, scientists from many agencies have joined efforts. The U.S.
Geological Survey (USGS), the U.S. Environmental Protection Agency (EPA), and the National
Oceanic and Atmospheric Administration (NOAA) have joined together to monitor and assess
the ecological conditions in the coastal waters that were impacted by Katrina. These agencies
have collected extensive data on the ecological impacts created by Katrina by comparing and
assessing the pre and post conditions of the Lake. Many scientists conducted surveys to gather
data on factors such as water-quality indicators, biological indicators, and sediment-quality
indicators. Many results were realized by the surveys conducted so far, but sampling surveys are
still in place to this day. Although Hurricane Katrina did appear to have major impacts on Lake
Pontchartrain, surveys have indicated that the impacts on the ecological health are not as great as
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one might think. Actually, there were improvements in some indicators such as the upgrades in
dissolved oxygen conditions (fair to good) and dissolved phosphorus (poor to fair). However,
much of the aquatic life was greatly impacted and is still being studied today.
There is debate among scientists and their beliefs on the effects that Katrina had on the
Gulf of Mexico. Some believe that that long-term damage of the toxic floodwaters that have
entered the Gulf of Mexico will not be a high risk. These scientists believe that the toxic
substances will be diluted to non-harmful levels through tidal flows and the flushing of Gulf
waters. They also believe that through natural processes, bacterial contaminants and other
organic material will die off quickly. Other scientists view this impact differently and contend
that the excess nutrients and toxic substances will greatly impact fisheries by killing fish and will
contaminate sediments in the water. Another debate among these scientists is the impact of
Katrina on the annual dead zone in the Gulf. Some contend that there will not be an increase in
the intensity of the dead zone caused by excess nutrients because of the timing of the influx.
Others believe the exact opposite as toxic material and excess nutrients will greatly influence the
intensity of the dead zone in many seasons to come. The effects of Katrina on the annual dead
zone in the Gulf of Mexico is still uncertain but will be assessed in the years to come.
Fisheries on the Gulf Coast were significantly affected by Hurricane Katrina as
commercial and recreational fishing were greatly impacted. The Gulf Coast produces 10% of
shrimp and 40% of oysters that the U.S. consumes. The destruction of fishing boats, processing
facilities, and storage facilities severely damaged shrimp and oyster production throughout this
area. Katrina created significant impacts on fish populations, their viability, and their habitats.
Studies conducted on oysters by the Louisiana Department of Fish and Wildlife has shown initial
estimates of 99% oyster loss in Louisiana waters. This study was done by relating the effects
hurricanes Ivan and Andrew to estimate the effects of Katrina on resource mortality. Oysters are
an example of filter feeding organisms that willingly uptake toxins and excess nutrients making
them more vulnerable to contamination, leading to health issues in people that consume them.
As of 2005, many of the long-term impacts that Hurricane Katrina had on fisheries is uncertain.
Numerical estimates of habitat loss are still underway with the help of satellite imagery and
sampling studies conducted by the NOAA.
Recovery Process
Due to these environmental impacts, Hurricane Katrina has resulted in one of the largest
natural disaster recovery operations in the history of the United States. Recovery has been a long
process that still continues today. The immediate clean up focused on unwatering the flooded
city and evaluating potential hazards. Debris management was the next task after floodwaters
receded. Shortly after the disaster occurred, the Environmental Protection Agency (EPA) and the
Federal Emergency Management Agency (FEMA) led the way in assessing damages, testing
environmental conditions, and beginning the cleaning process. They examined water, air,
sediments, drinking water, wastewater, and hazardous waste facilities to assess the level of
contamination. In addition, two major planning committees surfaced, the Neighborhood
Rebuilding Plans (Lambert Plans), and the Unified New Orleans Plan (UNOP). Furthermore,
individual neighborhoods partnered with nonprofit organizations and universities to rebuild their
areas. Rebuilding began in areas with the least damage in hopes of a short term solution to allow
people to move back to the city as soon as possible. By 2010, the population was about 80% of
what it was before the hurricane, but 29% of the buildings remained damaged.
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Another challenge presented in the recovery process was acquiring the necessary funds to
rebuild the city. The city prepared a plan that was approved by FEMA in 2006 to allow for $57
million in Hazard Mitigation Program funds. An additional $411 million was provided in
Community Development Block Grants (CDBG). By 2010, Hurricane Katrina cost about $157
billion. Clearly, the recovery process was and still is devastating to both the environment and the
economy.
Furthermore, the cleanup process poses a variety of additional environmental impacts.
Debris management is crucial in protecting public health and safety as well as the environment.
When the debris removal is complete, the Army Corps of Engineers predicts that the debris for
Louisiana will be around 46 million cubic yards. This estimate does not include the debris
generated from the demolition of private properties. Some of the types of debris were municipal
solid waste, construction materials, vegetative debris, household hazardous waste, white goods
(refrigerators, freezers, washers, dryers, etc.), and electronic waste. This debris can contain
harmful substances like asbestos and pesticides. After collecting and sorting debris, some is
taken to landfills, recycled, or burned. The vegetative debris is mulched and used to cover
landfills.
Moreover, the disposal of oil and hazardous substances requires careful handling to
reduce risks of endangering the public and the environment. The Coast Guard reported that it
responded to 6 major, 3 medium, and 132 minor oil spills in southern Louisiana alone.
Approximately 8 million gallons of oil were released from storage tank facilities. This oil spill is
comparable to the 1989 Exxon Valdez oil spill which released 11 million gallons of oil into the
ocean. There were also over 2 million hazardous material containers collected in southern
Louisiana. The EPA estimated that these storage containers contained hundreds or maybe even
thousands of gallons of hazardous materials.
Another hazardous element regarding the recovery process was the contaminated flood
waters. The water that initially flooded the city was not contaminated, however it became so
when it mixed with human and animal sewage, decaying bodies, oil, gas, and chemicals in the
city. The management of these floodwaters produced short and long term challenges. They had
to address the obvious impacts on public health and the environment. The tests conducted by the
EPA showed high concentrations of fecal bacteria in the floodwaters that also threatened the
health of the public. Additionally, they had to manage the discharge of the contaminated waters.
Much of the contaminated water was dumped into Lake Pontchartrain, which raised more
environmental concerns and caused negative impacts on the lake’s ecosystem.
Conclusion
Hurricane Katrina was one of the deadliest and devastating natural disasters in United
States history. The damage it caused ruined a countless number of people’s lives. It also
damaged thousands of acres of both aquatic and terrestrial ecosystems. Recovery efforts have
been going on for some time now to try and rescue the lands affected by the hurricane as well as
manage the thousands of gallons of waste that were released into the area. Though the recovery
efforts are going well, it will still be some time before the land is back to the way it was before
the hurricane.
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References
1. DeVol, Ross. "The Economic Impact of Hurricane Katrina."milkeninstitute.org. Milken
InstituteAssociates, 09/1. Web. 29 May 2012.
<http://www.milkeninstitute.org/events/events.taf?function=detail&ID=160&cat=mia>.
2. "Facts about Hurricane Katrina." National Geographic . do something .org, n.d. Web. 29 May
2012. <http://www.dosomething.org/tipsandtools/11-facts-about-hurricane-katrina>.
3. Heitmuller, P. Thomas, and Brian Perez. "Environmental Impact of Hurricane Katrina on Lake
Pontchartrain ." . N.p., 2005. Web. 29 May 2012.
4. McGuire, Michael, and Debra Schneck. "What if Hurricane Katrina Hit in 2020? the Need for
Strategic Management of Disasters." Public Administration Review, 70 (2010): s201.
5. Sheikh, , A. Pervaze. "The Impact of Hurricane Katrina on Biological Resources." CRS Report
for Congress. N.p., 2005. Web. 29 May 2012.
6. Walker, David. "GAO's Preliminary Observations Regarding Preparedness, Response, and
Recovery: GAO-06-442T." GAO Reports. (2006): 1. Web. 29 May. 2012.
<http://www.library.uni.edu/gateway/xerxes/ui/ebsco/record/f5h-20087763>.
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