Effects of Hurricane Katrina on Local Environment

Effects of Hurricane Katrina on Local Environment

By: Bethany Olson, Dan Wieland, Joe Zhiss, and Victoria Nicholas

Group 5

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 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 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 waterbody 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 stormwater 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 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.

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.