COASTAL LAND LOSS: HURRICANES AND NEW ORLEANS

Ivor L. van Heerden, Ph.D.

Center for the Study of Public Health Impacts of Hurricanes

LSU Hurricane Center, Louisiana State University, Baton Rouge, LA 70803, USA

ABSTRACT

Recent tropical cyclone-induced floods in the United States, and elsewhere, have demonstrated the complexity of public health impacts including trauma; fires; and chemical, sewerage, and corpse contamination of air and water. Disease risk in Louisiana during hurricanes/major floods is very high reflecting forty percent of the state is coastal zone in which 70% of the population resides. Ninety percent of this zone is near/below sea level. Densely populated areas, such as New Orleans, rank among the highest in the United States with respect to potential societal, mortality, and economic impacts.

Louisiana’s outer buffer to storm surges are its coastal wetlands and barrier islands. Since 1930, one million acres have been lost, 400,000 acres seawards of New Orleans. In 1990 the State and Federal Governments initiated a coastal restoration program with total expenditures to date of $400 million. However, even with these efforts land loss still exceeds 28,000 acres p.a.

The City of New Orleans was built on wetlands. Leveeing and draining has resulted in substantial subsidence such that most of New Orleans is now below sea level, with a maximum deflation of 13 feet. Within this bowl reside approximately 600,000 people. The West Bank, south of New Orleans and across the Mississippi River, has a population of about 500,000 who also live within levee protected bowls. Recent research reveals that a slow moving Category 3 hurricane, or stronger, could cause levee overtopping and complete flooding of New Orleans, with the West Bank even more susceptible. Floodwaters would have residence times of weeks. The resultant mix of sewage, corpses and chemicals in these standing flood waters would set the stage for massive disease outbreaks and prolonged chemical exposure. Estimates are that 300,000 persons would be trapped and 700,000 would be homeless; thousands could perish.

There is a need to develop and implement a long-term coastal restoration plan to ensure New Orleans survival. A project that appears to have the greatest potential of reducing hurricane storm surges impacting New Orleans requires the diversion of the Mississippi River into Breton and Chandeleur Sounds through the Bohemia Wildlife Management area (van Heerden, 1994). If enacted, approximately 5,000 acres of new wetland would be created in this stable basin every year. Large-scale coastal restoration efforts will positively affect New Orleans future.

ENVIRONMENTAL SETTING

Coastal land loss in Louisiana

The coastal wetlands and estuaries of Louisiana are one of the world's great ecosystems. For millennia, the Mississippi River has supplied the coast with an immense resource of freshwater, nutrients, and sediment to build a vast expanse of marsh and swamp land. These lands have been altered by natural erosional processes. The dynamic interplay of land and water, where new lands are continuously built and old lands changed and lost, has produced an environment rich in natural habitats, with an unsurpassed diversity in vegetation, wildlife, fisheries, and an extraordinary biological productivity. Louisiana's marshes and swamps, which encompass four million acres, represent over 40% of the coastal wetlands in the United States and provide 30% of the country's annual commercial harvest of fish and shellfish (van Heerden, 1994). Millions of people rely directly or indirectly on the marshes for their livelihood and for protection against hurricanes and storms. Natural habitats benefit from the wetland's ability to improve water quality. The delta is the heart of "Cajun" culture, which combines natural beauty, abundant wildlife, and rich sport fisheries to provide a unique tourist attraction. The delta also is of enormous economic importance in ways indirectly related to wetlands, especially because it produces some 15-20% of the nation's oil and almost 30% of its natural gas and because the Mississippi River ranks as the country's most important inland navigational waterway (van Heerden, 1994).

In the last several decades, however, humans have impacted this ecosystem in many ways, especially by controlling rivers so natural floods are no longer a part of wetland maintenance and creation, and by building channels that expose freshwater marshes to salt water at an unnatural rate. Levee systems and control structures confine sediment that once nourished the wetlands adjacent to the river channel. Ultimately, sediment deposition is in the deep waters off the Louisiana coast. The lack of sediment input in the interdistributary wetlands results in an accretion deficit. Natural and human-induced subsidence exceed accretion so the wetlands sink below sea level and convert to water. Statistics only begin to suggest the importance of the ecosystem and the extent of modern damage.

As the twentieth century progressed, the Louisiana coast lost its incredibly fruitful wetlands at an increasing rate to reach about 40 square miles per year in the 1970's. Louisiana's loss represents 80% of all coastal wetland loss in the United States. The lost land has been conservatively valued at $4,000/acre in terms of natural services (recreation, aesthetics and water purification) and productivity (fish, shellfish, and fur) (Costanza and Farber, 1985; Houck, 1983). Assuming a real estate value of $400/acre and a similar value in terms of protection the coastal wetlands represent for coastal communities from major tropical storms, means that the annual loss to Louisiana and the nation exceeds $150 million every year (van Heerden, 1994). In fact, since the 1950's this loss in total amounts to an excess of $7.6 billion. Recently, the rate has slowed slightly, but losses of tens of square miles per year still occur (approximately 100 acres/day). Total wetland loss since the turn of the century has been over one million acres, an area 1½ times that of Rhode Island (Templet and Meyer-Arendt, 1988).

Loss of wetlands means more than loss of the prevailing resource base. Life and property are increasingly threatened as the populated, low-elevation natural levee lands become more exposed to the Gulf of Mexico. The loss of storm-buffering protection by wetlands and barrier islands not only jeopardizes the safety of isolated bayou communities but also the New Orleans metropolitan area. The potential impact of a hurricane directly striking the city is much more serious today than in decades past because of the increased storm surge levels expected with adjacent open-water conditions (Templet and Meyer-Arendt, 1988).

Much of the physical cause of the wetland loss problem lies in attempts to control the Mississippi River's flooding, while enhancing navigation and mineral extraction. Many signs indicate that if nothing is done, large rates of loss will continue--and in some areas perhaps increase--far into the future. The ultimate economic cost will be tens of billions of dollars and beyond that, immeasurable environmental damage.

HURRICANE PUBLIC HEALTH ISSUES AND THREATS

The Hurricane Threat

The world is at ever-increasing risk from hurricanes, tropical cyclones, and major flooding events. Population growth and global migration patterns toward at-risk coastal areas; increased development and urbanization of the coastal zone; long term climactic trends; and other factors combine to expose growing numbers of people to hurricane and flood threats. These threats include storm surge flooding, extreme winds and tornadoes, rainfall-induced flooding and landslides, and coastal erosion.

Storm phenomena, damage, and direct casualties are generally investigated and documented by the engineering and scientific communities. Less well investigated, understood, and accounted for in future planning are the public health issues that arise immediately in the wake of hurricanes, tropical storms, other severe flooding events, and thereafter. Disease outbreaks can occur and trauma-related mental health problems are common (Noji, 1997). People are often exposed to high levels of biological and chemical contaminants in floodwaters, which can have immediate and/or long-term health consequences. Additionally, the transport and fate of these contaminants is largely unknown. Many remain in the environment, contaminating soil, houses and other buildings and water supplies, leading to potential long-term health problems (Noji, 1997).

The past few years have witnessed several massive storms. Hurricane Mitch in 1998 devastated much of Honduras. Direct casualties were estimated at 9,000, but the full impact will not be known for many years. India and southern Africa have experienced major cyclone-induced flooding in which thousands perished. Hurricanes Floyd and Irene, and more recently Isabel, pounded North Carolina and the rest of the East Coast, causing some of the most severe flooding on record. Animal wastes, carcasses, and other sources contributed to extremely high levels of contamination of the floodwaters, posing immediate and long-term health threats. Tropical storm (T.S.) Allison dropped in excess of two feet of rain, in a few days, over portions of Texas and Louisiana. A major concern was disease due to an explosion of mosquitoes.

On a national scale, 45 million Americans live in coastal counties alone stretching from Texas to Maine (Jarrell et al, 1992). These coastal counties have the highest population growth rates in the United States (FEMA, 1997). While these people are generally at the highest risk, severe flooding can threaten residents much farther inland as well. Louisiana has as much if not more risk from hurricanes and other flooding events than any other state. Over the past century, south central Louisiana has experienced what appears to be the highest number (6) of landfalls of major hurricanes (Category 3-5 storms – Figure 1). Louisiana and Texas typically rank numbers one and two, in annual flood insurance claims. New Orleans is the most vulnerable major city on the Gulf Coast and perhaps in the entire United States. Had Hurricane Georges not taken a last minute turn to the east in 1998, major portions of New Orleans would have flooded. It would likely have been one of the worst disasters of the century in terms of loss of life and damage.

The catastrophic flooding in coastal North Carolina as a result of Hurricane Floyd serves as a frightening example of potential future threats to public health caused by high water. Public health risks during potential massive flooding events in Louisiana are at least as high as those experienced in North Carolina. However, major differences are that Louisiana, lacking the topographic slopes of North Carolina would drain much more slowly and standing water could be a problem for many weeks. Additionally, Louisiana has extensive infrastructure of oil and gas facilities, chemical plants, and hazardous, industrial and residential landfills. Most of these facilities are in flood prone areas and within the confines of levee systems protecting housing and other structures from flooding. Even in areas where mitigation strategies have been engineered (i.e., levee, drainage, and pumping systems), such designs are unable to capture and control all storm water run-off from the occasional extreme rain event. Further, hazards associated with these events can be prolonged over periods of days to weeks, as the region’s generally low-lying and flat terrain can extend residence times of floodwaters. As a result, the array of potential health risks associated with large-scale flooding may be exacerbated by the persistence of standing water within impacted areas.

Hurricane Public Health Research Initiative

There is a need to develop and implement a long-term coastal restoration plan that rapidly rebuilds the coastal wetlands. In the interim, the range of severity of public health impacts are being researched and plans are being developed for mitigation, preparedness, response and recovery to minimize both the long- and short-term health impacts. Towards this end, the Center for the Study of Public Health Impacts of Hurricanes was created at Louisiana State University in 2002. The center consists of a multi-disciplinary, multi-campus team comprising natural and social scientists, engineers, and the mental health and medical communities. Utilizing computer models, storm surges and rainfall flooding scenarios are being determined. Computer models are being used to simulate air and water movement of chemical contaminants. GIS technologies allow documentation of at-risk areas. Epidemiologists, toxicologists, social scientists, and public health experts will then determine public health impacts. These will be assessed against a realization that the Pacific Decadal that began in late 2000 is expected to last for 10-30 years and cause harsher weather patterns with an increased incidence of hurricanes. This, against a backdrop where Louisiana is losing wetlands and sea-surface temperatures are rising.

Facts to consider in developing the medical response include global temperature rise that would extend the domain for malaria and dengue fever (including other forms of these diseases from Central and South America). A 4º F rise would extend the domain from the current 42% to 60% of the earth’s landmass. In this scenario, tropical diseases would become endemic to many temperate areas such as the US and Europe. Global warming is expected to contribute to an increased incidence of food and waterborne diseases.

Some common short term public health impacts noted following recent flooding events (Hurricane Andrew and TS Allison) include: increased risk of disease due to crowding (or being housed with homeless); water contamination and resulting gastrointestinal disease; increased arthropod and animal vector diseases; snake and animal bites; and injuries (e.g., jumping off of roofs, motor-vehicle accidents). Some of the chronic health impacts include: upper respiratory infections, headache, chronic illness and stress.

Louisiana, like other Gulf and Atlantic coastal states, needs to prepare and develop plans to deal with public health risks during major floods. During a disaster, citizens may be exposed to environmental sources of disease from a variety of hazardous material sources. Public health outcomes that can result from such complex disasters include contamination of drinking water, buildings (e.g. toxic mold), agriculture production areas, wetlands, and water bodies that are both habitat and sources of food (e.g. fish and wildlife). This, in turn, creates the potential for immediate disease epidemics and the potential for long-term genetic abnormalities and health problems. All of these potential public health outcomes must be identified; preparedness, mitigation, remediation, and recovery techniques must be developed now, before a major flooding disaster occurs in Louisiana.

Hurricane Public Health Research

The overall objective of this LSU public health research center is to develop the science, technology and medical know-how to assess the public health impacts resulting from hurricanes and major flooding events. This objective also includes the development of remediation approaches to these impacts. A flowchart summarizing the major research activities and interrelationships is given in Figure 2.

There are two levels of data collection and modeling of the physical phenomena and community response. These tasks provide the inputs necessary to adequately understand and model the public health threats, outputs of which will be used to develop suitable mitigation, preparedness, response, and recovery plans and procedures. Most of the data and modeling will be within a GIS framework.

The focus of the physical systems modeling tasks is to provide needed inputs for the public health impacts modeling. Physical modeling tasks began with identification and selection of the most appropriate existing models, followed by application of the chosen models to the specific problems defined by the study area. The real research challenges are the coordination and integration with all of the other disciplines that are providing and using the model outputs. With such a multi-disciplinary research project, this is a crucial component, as formulation of all models to work within a consistent GIS framework requires extensive coordination and cross-disciplinary teamwork.

INITIAL RESEARCH RESULTS

Will New Orleans Flood?

New Orleans was built on wetlands. Leveeing and draining has resulted in substantial subsidence such that most of New Orleans is now below sea level, with a maximum deflation of 13 feet. Within this bowl reside 600,000 people. The West Bank, south of New Orleans across the Mississippi River also has a population of 500,000 who live within levee protected bowls. Computer simulations using both the SLOSH (Sea, Lake and Overland Surges from Hurricanes is a computerized model run by the National Hurricane Center) storm surge model as well as the ADCIRC (a parallel ADvanced CIRCulation model for oceanic, coastal and estuarine waters) model show that a slow moving Category 3 storm, on any number of tracks, could flood New Orleans, from levee to levee, completely filling the bowl. For Category 4 and 5 storms the situation looks even bleaker.

The Gulf of Mexico is a very favorable environment for the formation of intense hurricanes. Unlike other hurricane prone areas which don’t provide enough retention time for storms to build, Gulf of Mexico waters are extremely warm in the late summer/early fall with a potential to support Category 5 storms (>155 mph wind speeds). The Gulf of Mexico is a region of the world where intense hurricanes not only form, but intensify rapidly due to conditions favorable to their development. Additionally, the Gulf of Mexico is an area where storms can be intense and form quickly; they are also numerous. In the last 50 years, six major storms (Category 3 or above – Figure 1) have made landfall in Louisiana; which included Audrey (1957, Cat 4); Hilda (1964, Cat 3); Betsy (1965, Cat 3); Camille (1969, Cat 5); Carmen (1974, Cat 3); and Andrew (1992, Cat 3). As evidenced from the tracks of these six major storms, New Orleans has not sustained a direct hit, but has had quite a few narrow misses. Such storms often do not provide much lead time for evacuation.

On the positive side, Louisiana’s populated areas are located further inland from the coast (as opposed to a city such as Miami, FL), since storms tend to dissipate as they come inland. It generally takes four to six hours for a rapidly moving hurricane to move inland over New Orleans, and in that time, a 25-35% reduction in hurricane force may be realized.

Hard and firm rules do not apply to rainfall. Looking historically at some of the rainfalls that have been associated with tropical storms and hurricanes in the area, one of the largest events occurred in 1940 in Southern Louisiana, where over 30 inches of rainfall was recorded (Robbins, 2003). More recently, when TS Isidore tracked over New Orleans, winds weren’t much of a problem but rainfall was, pouring 26 inches of rainfall

into New Orleans. Thus Historical data on tropical storms and hurricanes demonstrate that 15-20 inches of rainfall is not uncommon.

Figure 1: Major Hurricanes (with track and intensity) that have made landfall in Louisiana in the Past 50 years. (NOAA, courtesy Kevin Robbins, SRCC)

The New Orleans storm of May 1995 (26 inches of rain) resulted in 37 hospitals being impacted. During the flooding 68% of these hospitals had access routes blocked by flooding and debris; 44% of hospitals cancelled all elective procedures, canceling all surgical procedures; 32% had nursing shortages; 25% had doctor shortages; 18% had no sewage; 11% had no potable water; 7% had medical supply shortages; and 4% had food supply shortages.

How many folk will stay in a major storm?

A baseline survey has been collected from a random sample of 1,000 New Orleans residents. The primary data collection technique involved telephone surveys, with the sample selected via random-digit dialing. However, New Orleans contains many areas with high concentrations of poverty that could be designated underclass, because substantial portions of the population are either below the poverty line or living in extreme poverty. Representing the social and economic resources and the potential health needs of that segment of the population is both critical and difficult, because this segment of the population is least likely to evacuate. With the aid of social workers, these individuals were sampled in a door-to door survey.

The primary focus of the survey is to understand how residents of the New Orleans area would prepare for and respond to a major hurricane. First, we are assessing the network structures and resources of these residents to better understand the kinds of resources they have available, and to gain some sense of the extent to which individuals would use formal and informal sources of help. Second, we are asking residents about their past hurricane experience and how they would respond if a storm as dangerous as Andrew approached the New Orleans area. We include questions on past hurricane experiences; the availability of transportation; and how, under what circumstances, and in what direction they would evacuate if a hurricane approached the New Orleans area in the future. These questions include asking whether they know someone to whom they could go and whether they would go to a motel/hotel, shelter, someone’s house, etc. if they evacuated. The questions include a third expanded section on hurricane evacuation. This section allows us to gain vital information on how the direction and severity of an approaching hurricane would affect the decision to evacuate and the timing of the evacuation. With all of this information, we will be able to better understand well the social and economic resources of New Orleans area residents. We will also gain more detailed information on evacuation response (Hurlbert, 2003).

Preliminary data from the survey are now available. Overall, 68.8% of respondents would leave the area, 9.8% would leave their homes but remain in the area, and 21.4% would remain in their homes. That 21.4% of respondents would remain in their homes is a startling and important statistic. This , because it indicates that nearly 1 in 4 New Orleans residents would refuse to leave their homes as a possibly deadly major hurricane approaches the City.

Evacuation Issue – Can They All Get Out?

Important research questions regarding evacuation include:-

· Assessing the effectiveness of the planned evacuation strategy for New Orleans and, by default, other similar strategies around the US;

· Using these results to develop alternative strategies that may be more effective than those currently planned;

· Testing these alternative strategies to determine if they would be more effective at moving evacuees than the ones currently planned.

A traffic model to simulate the operation of evacuation traffic out of New Orleans, with specific emphasis on the I-10 westbound contraflow segment from approximately Loyola Avenue to the vicinity of the I-10/I-55 interchange has been developed. This started with a base model constructed using the CORSIM (CORridor SIMulation) software package (Wohlson, 2003). An additional project centered on the traffic and congestion characteristics associated with various planned contraflow termination point configurations, including the one in New Orleans.

While it has been widely suggested that the use of two contraflow lanes would increase the capacity of a four-lane freeway by about 70 percent, there has been insufficient data and analyses to support this claim. Experiments have now shown, however, that the total exiting evacuation volume on I-10 increases by about 53 percent over a standard two-lane configuration with contraflow (Wohlson, 2001, 2003). The most significant finding, however, is the critical role played by the entry point and the plan to load vehicles into the contraflow lanes. Since the inception of contraflow evacuation, emphasis has been placed on the location and control of the segments because it has been assumed that the segment length and termination design would dictate the effectiveness of the operations. However, new research suggests that the segment itself does little good if adequate capacity is not provided at the point where vehicles enter the segment. These results further suggest that the contraflow segment planned for westbound I-10 out of New Orleans will likely create a bottleneck. This would lead to the typical three-state flow condition in which traffic conditions upstream of the restriction would be heavily congested, then flow at near capacity rates through the restriction, before flowing in a near free-flow state downstream of the restriction. Under an evacuation scenario this condition can potentially have both positive and negative aspects. Most critically, the entry congestion would be a significant problem because it would slow the departure of vehicles from the threat area. In New Orleans, where in excess of 120,000 vehicles are expected to use this segment within a short period (24-72 hours), monumental traffic congestion would likely occur. However, the use of downstream entry points after the restriction could at least partially offset this problem by helping to fill the underutilized contraflow segment (Wohlson, 2003).

CORSIM simulation results show that when there is no available exit-ramp for traffic to exit along the evacuation route, merging conflicts and traffic congestion are expected to occur before the one-lane closure. Although it might not always be possible to exit 50 percent of the total traffic, these results showed that increasing the exiting vehicles using more available exit-ramps improved the efficiency of the contraflow operations.

The models also showed that traffic flows tended to drop dramatically when the speeds were less than approximately 30 mph. On both the contraflow and normal flow roadways, the critical density and critical speed were around 40 vehicles per mile per lane (vpmpl) and 30 mph, respectively. Maintaining the densities on the freeway below the critical density and above the critical speed can ensure higher traffic flow (Wohlson, 2003).

Public Health Outcomes, Phase One - Immediate Impacts

Present Corps of Engineers predictions are that if the New Orleans bowl fills, it will take 9 weeks to pump all of the water out, assuming the necessary permits are obtained. There will likely be a strong push by commercial fishing interests to restrict the out pumping for fears the contaminated water will severely impact the harvestable marine and estuarine species. Air evacuations by helicopter will ensure the evacuation of thousands a day, but at the same time there will have to be mechanisms set up to get food, water and medicines to those trapped. An “Operation Dunkirk” effort will have to be launched from the north shore of Lake Pontchartrain, utilizing sport fishing and recreational boats to collect stranded New Orleans residents from the levees on the north side. On the south side, barges and commercial vessels will do their own river evacuations to centers such as Baton Rouge. Within the flooded city, where water levels in many areas will reach the eaves of houses, another small craft operation will have to be set up moving people and supplies to and from their places of refuge to the levees (high ground) and vice versa. This “Operation Dunkirk” evacuation and supply operation, using mostly volunteers, is going to require significant planning. Each crew will need emergency supplies and radio/cellular phone communications, a stock of medicines, and medical experts with whom to communicate. Insurance issues and waivers will have to be negotiated.

Survivors of those who rode out the storm in New Orleans will have trauma cases from projectiles as well as collapsing structures and the concomitant risk of tetanus. The immediate health problems for survivors will certainly include high incidences of diarrhea and other gastroenteric problems due to contaminated water, stress, worsening personal hygiene, and chemical intoxications. Evacuation centers will have to deal with people who left home without adequate supplies of their prescribed medications. Altogether there will be a rising cycle of medical problems. Although most citizens will be helpful and altruistic during the disaster, security issues will nonetheless arise.

Additionally, despite the widespread flooding, there will be a significantly increased risk of fires in New Orleans from barbecues, portable stoves, open cooking fires, candles, and lanterns. Remaining occupied structures, abandoned warehouses, high-rise office buildings, and all unflooded upper stories - many serving as commandeered shelters - will also face increased fire risks from downed power lines, disrupted floating gas lines, and gas pockets trapped in roofs and upper stories. Unfortunately, these fire risks will be met by understaffed and inadequately equipped firefighting and EMS personnel. Local fire departments will be denied ground access, will have inadequate airborne and marine firefighting equipment, and will have no water pressure except that supplied by siphon pumps.

Many storm and flood refugees will have been inadequately vaccinated for measles and influenza, and unvaccinated for pneumococcal pneumonia and bacterial meningitis. These highly communicable, yet vaccine-preventable diseases, cause frequent epidemics among military recruits crowded in base camps, as well as refugees crowded in temporary shelters. Public health personnel will require adequate pre-existing stocks from the strategic national stockpile of the appropriate vaccines in order to offer timely vaccinations to large numbers of displaced persons in crowded conditions (Diaz, 2003). The homeless pose communicable disease threats (STDs, especially HIV/AIDS, and multi-drug resistant TB) and infectious disease threats, such as typhus and hemorrhagic scabies, if crowded in shelters with susceptibles. Getting survivors out of the flooded city, ensuring adequate flood and water supplies and rapid access to medical support are essential elements of Phase One.

Phase Two - Initial Recovery

During the time from the end of the first week to the second month (initial recovery) there will be complex human population fluxes - people allowed home, others kept in evacuation centers, movement from one center to another, further evacuations, and possibly a floating uncontrolled criminal population. In terms of health consequences, this period will be characterized by continued stress and the appearance of mental health problems. There will be an increasing incidence of stress-related infections, asthma, and other respiratory diseases and lethal pneumonias, such as Legionella and pneumococcal pneumonia, especially in the elderly, the very young, and the immunosuppressed. Various parasitic infections could emerge as additional communicable disease threats following weeks of outdoor living, inadequate sewage treatment, inadequate personal hygiene and hand washing, and vicarious defecation. There will be a potential for encephalitis, dengue, and other arboviral infections. Food delivery problems will result in contaminated food outbreaks and, because this state is fond of seafood, there is also the potential for various rotavirus, calicivirus, hepatitis A, paralytic shellfish poisoning, and Vibrio spp. outbreaks, including cholera. Chemical toxic conditions should decrease during this time. However, toward the end of this phase there will be a surge in infectious disease diagnoses, by inadequate diagnostic laboratory capabilities (Diaz, 2003). A major component of this period will be the urgent need for aggressive mental health programs and getting children back into structured lives and school to prevent longer-term juvenile problems. Recovery will have faster and slower recovering components. Noji (2001) stresses the need for better epidemiologic knowledge of disasters to better facilitate relief efforts.

Communicable vs. Non-Communicable Disease and Conditions

Of the communicable diseases, waterborne diseases will likely be the most common, followed by food borne, vector borne, and airborne-respiratory, in that order. Waterborne diseases and conditions would result more from human feces (E. coli, Shigella, Salmonella, HAV, caliciviruses, and amebic) but also animal feces (Cryptosporidium, Cyclosporidium, and Giardia). Food borne problems would result from spoiled food in refrigerators from loss of power or eating raw shellfish, and include exposures to the Staph aureus enterotoxin, Salmonella, Shigella, Campylobacter, non-cholera Vibrios, and caliciviruses. Vector borne disease would be primarily caused by mosquitoes (e.g., West Nile (in which most cases are asymptomatic)), zoonotic vectors, which can cause more serious problems (e.g., St. Louis Encephalitis (SLE)), rodent vectors (which can cause leptospirosis), fleas, and ticks (e.g., which can be vectors for Lymes disease and related conditions). Airborne-respiratory diseases would include upper respiratory infections (URIs), the flu, and measles (Diaz, 2003).

Non-communicable conditions likely to follow hurricanes and floods, will include psychological, musculoskeletal (primarily falls), chronic diseases (or exacerbation of current conditions), and physical and toxic exposures, in that order. Physical conditions would include drowning, near-drowning, submersion, hypothermia, electrocution, and burns. Toxic conditions would include Carbon Monoxide (CO) and Nitrogen Oxide (NOx) poisoning at the top of the list (which result most commonly from operating a generator indoors); chlorine & phosgene gas exposure (ubiquitously available on tank farms in neighborhoods), exposure to Volatile Organic Chemicals (VOC’s): benzene, MTBE, TCE, and perchloroethylene. Possible psychological conditions would include anxiety, aggression, anger, insomnia, estrangement, depression, Post-Traumatic Stress Syndrome (PTSS), and disaster shock. Musculoskeletal conditions would also include strains, sprains, dislocations, and fractures. Exacerbated and chronic conditions would include Myocardial Infarction (MI)/heart attack, Cerebrovascular Accidents (CVA)/stroke, and diabetic conditions/ Diabetic Ketoacidosis (DKA) (Diaz, 2003).

A stockpile of measles vaccine is thus very important, possibly the most import in terms of primary prevention. MMR (2-3 sets of vaccinations), a current flu shot (annual), and tetanus within at least the last ten years should be priorities for any citizen who decides they will not leave, or who cannot leave. A measles outbreak, particularly in shelters or conditions of close living quarters for extended periods of time, would be a high probability. Measles has long incubation phase (around 21 days) when it becomes highly infectious, so if this comes into a shelter, and many have not had measles immunizations, or have only have incomplete vaccinations, a measles outbreak could rapidly spread with high morbidity and mortality in both children and adults. Measles is the most common killer in refugee camps.

In summary, the main vaccines that should be stockpiled in preparation for a flooded New Orleans include: influenza, pneumococcal pneumonia, measles, rubella, and pertussis; and not cholera or typhoid, which have been recommended for mass vaccinations in the past.  Cholera is an ineffective vaccine, and typhoid should be reserved for travelers only (Diaz, 2003).

A COASTAL RESTORATION PLAN TO SAVE NEW ORLEANS

The New Orleans catastrophe is real and a major fix is needed, namely extensive coastal restoration efforts. The development of the most viable proposed restoration plan to protect New Orleans from hurricane risks has been guided by the following principles (van Heerden, 1994):

•Restoration projects must benefit the local communities of Louisiana's coastal zone and not result in a reduction in long‑term economic viability. Specifically, restoration projects must be designed to maintain at least the level of flood protection and transportation infrastructure currently in effect. Projects that will unavoidably result in displacement of facilities and natural resource harvesting areas should be implemented gradually and include funding to offset unavoidable short‑term economic dislocations.

•Restoration projects must maintain and enhance the long‑term biological productivity and biodiversity of Louisiana's estuarine systems that provide the primary impetus for restoration.

•An effective long‑term restoration strategy must re-establish large‑scale natural deltaic wetland creation and maintenance processes using seasonally pulsed sedimentation and freshwater input from the rivers to counter the sediment accretion deficit.

Creation of Productive, Sustainable Wetlands through Major Freshwater Diversions from the Mississippi River.

Two approaches must guide our thinking: 1) can we initiate a new locus of deposition for Mississippi River sediments in areas that will result in significant wetland creation in the long‑term? and 2) can we create new distributaries or revitalize existing distributary channels to once again deliver sediments to areas some distant from the river?

Breton-Chandeleur Sound encompasses 1200 square miles. It is an area dominated by shallow bays. These water bodies are protected from the direct impact of Gulf of Mexico's wave energy by the Breton-Chandeleur Barrier Island chain. The region's shallow bays, coupled with subsidence rates of about 0.5 ft per century, can serve as an excellent containment reservoir for Mississippi River discharge and sediment (NMFS, 1993; van Heerden, 1993b).

Creating a major Mississippi River diversion into Breton Sound, south of Bohemia opposite the village of Nairn, would begin a new delta cycle reversing wetland loss rates in eastern Plaquemines and St. Bernard parishes. It is proposed that an average discharge of 200,000 cubic feet per second (cfs) would pass through this diversion to create in excess of 5,000 acres (8 mi²) of wetlands each year (van Heerden, 1994). In 20 years, new wetlands totaling more than 140 square miles would be created. Moreover, water movements caused by tides, southerly winds in spring and summer, and coastal water level set-up proceeding cold-front passage in the winter would drive resuspended sediment into the St. Bernard marshes. Wetland loss in these marshes would be reduced considerably.

Diverting most of the Mississippi River flow into Breton-Chandeleur Sound implies abandonment of the Mississippi bird-foot delta. Wetland loss in this area is characterized by two problems: high subsidence rates (3 ft/century) and most of the Mississippi sediment being discharged into relatively deep water. Consequently, as the bird-foot delta is abandoned, it will be slowly reworked into barrier islands. These islands will coalesce with the Breton-Chandeleur islands to the east, and the shell/sand shoals/islands that form the seaward edge of western Plaquemines Parish. As a result, an almost continuous barrier island arc will extend from Grand Isle in the west to the northeastern tip of the Chandeleur Islands. These barrier islands will greatly aid in hurricane protection for the eastern half of coastal Louisiana; especially the greater New Orleans' metropolitan area (Van Heerden 1993a, b).

Without question, this new diversion will have some impact on navigation, along the Mississippi River and the Mississippi River-Gulf Outlet (MRGO). After all diversions presently proposed by state and Federal agencies are constructed, the Mississippi River's annual discharge would equal 200,000 cfs. If this flow was directed through Southwest Pass-the river's main navigation channel-the route could be maintained for deep-draft vessels. Ultimately a set of locks may have to be constructed from a point upstream of the town of Empire, connecting through Adams and Bastian Bays to the open waters of the Louisiana Bight. In the locks, flocculation and accumulation of fluid mud could be a problem that would require the development of a vacuuming system utilizing, for example, fluid-mud-jet pumps installed in the floor of the locks. The Scripps Institute of Oceanography in California has investigated siltation in slips and how to deal with it for the U. S. Navy. Thus, technology to address siltation problems in locks does exist.

In the first 10 years, the Breton delta's impact on MRGO would be minimal, but after 20 years the delta front would reach the channel. Thereafter, either MRGO would have to be closed and the necessary navigation infrastructure made, or the diversion and/or MRGO would have to be modified.

Over time, introduction of fresh water into Breton Sound would change the landscape of the region's commercial fisheries. Some existing oyster beds, for example, would have to be abandoned in favor of new ones being created in the bird-foot delta, or in eastern St. Bernard Parish. In 20 years, however, the Breton delta would create approximately 100,000 acres of new wetlands and significantly alter the character of the St. Bernard marshes-pushing them towards the fresher end of the spectrum and expand the marsh landscape. Further, the extended barrier island arc would have the ability to absorb a significant portion of any hurricane's energy, with positive consequences for New Orleans and adjacent communities. Navigation practices and channel maintenance within the Mississippi River, downstream of the diversion, may have to be changed and ultimately, a lock may have to be built connecting the river to the Louisiana Bight. If the delta were allowed to expand beyond MRGO, infrastructure changes would have to be made to accommodate closure of this channel. Assuming eventual closure of MRGO, this project could have a $ 3.0 billion price tag. Van Heerden (1994) has shown that the Mississippi River, even though the suspended load has decreased by at least 70% since 1850 (Kesel 1989), still carries enough sediment for restoration needs.

CONCLUSIONS

Flooding New Orleans is a real threat, a catastrophe that would severely impact the US economy, with ripples felt throughout the world’s economy. The problem is exacerbated with global warming. Louisiana would take decades to recover from such a catastrophe.

A solution to this problem is the diversion of the Mississippi River into Breton Sound and the creation of a new Mississippi Delta. Such a project would result in the genesis of significant amounts of new wetlands, improving the buffering of storm surges destined for New Orleans.

A large scale project of this nature will have other benefits. Biological productivity will be enhanced and biological diversity maintained. The expenditure of the billions needed for the Breton Delta project will generate many jobs over time. Additionally, the technology developed and applied by Louisianans will be exportable nationally and internationally, a product of the state’s enhanced knowledge and ability in coastal habitat restoration.

The Breton Delta project will also result in the improvement of the harvest potential of the natural resources, thus expanding the job base. In many coastal parishes, the harvest of natural resources is the main employer, or runs a close second to the oil industry. By enhancing the biological productivity of our coastal wetlands we will ensure the creation of new fishing and other opportunities. This is especially important as the oil industry job base is expected to continue to shrink. Additionally, tourism potential could be greatly enhanced. Visitors could be shown the restoration projects, which will be some of the largest ever attempted. New Orleans already attracts millions of visitors annually. By setting up the right infrastructure, these visitors could be enticed to spend some time in the coastal wetlands, injecting new money into local economies.

Not to act on Louisiana’s coastal land loss with all the facilities of government, is exposing New Orleans to greater threats than is necessary.

ACKNOWLEDGEMENTS

The results of research into the New Orleans catastrophe presented in this manuscript reflect the combined research efforts of all principal investigators of the Center for the Study of Public Health Impacts of Hurricanes. Without their dedication to this effort there would be little to report.

This research was supported by the Louisiana Board of Regents through the Millennium Trust Health Excellence Fund, Contract: HEF (2001-06)-01.

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