Report on the Damage Survey Caused by Hurricane Katrina (Tentative Report) November 1, 2005 Coastal Disaster Prevention Technology Survey Team 1. Introduction Hurricane Katrina struck the United States coastline of the Gulf of Mexico on August 29, 2005, causing destruction on a vast scale rarely seen in the history of hurricane disasters. The damage caused in this region has taught many lessons of great value to Japan that is in a frequent typhoon zone. Immediately after Hurricane Katrina devastated this region, the Port and Airport Research Institute contacted the American Society of Civil Engineers and universities in the region and sent Executive Researcher Shigeo Takahashi to take part in a field survey conducted by the Coasts, Oceans, Ports, and Rivers Institute of the American Society of Civil Engineers on September 22 and 23. Based on the results of this survey, the Port and Airport Research Institute formed a team of researchers, the Coastal Disaster Prevention Technology Survey Team (Team Leader: Professor Tomotsuka Takayama of the Disaster Prevention Research Institute, Kyoto University), to conduct a joint survey by the Disaster Prevention Research Institute, Kyoto University, the National Institute for Land and Infrastructure Management, and the Coastal Development Institute of Technology that are conducting research on coastal disaster prevention. This team surveyed the damage from Gulf Shore to New Orleans area and exchanged opinions with American engineers and researchers from October 26 to October 29. 2. Survey schedule Oct. 25, 2005: Oct. 26, 2005: Oct. 27, 2005: Oct. 28, 2005: Oct. 29, 2005: Oct. 30, 2005: Oct. 31, 2005: Travel (Tokyo Mobile Gulf Shore) Survey from Gulf Shore to Long Beach, travel (to New Orleans) Survey of urban New Orleans Survey of the Port of New Orleans and the Inner Harbor Navigation Canal, etc. Survey of the south-east area of New Orleans, travel (to Dallas) Travel (overnight in the air) Travel (arrival in Tokyo) 1
Gulf of Mexico to Tokyo Lake Pontchartrain from Tokyo Long Beach Mobile Gulf Port Biloxi New Orleans Mississippi River Gulf Shore Track of Hurricane Katrina Figure 1. Survey Locations 100km 3. Survey Team Members Kyoto University Dr. Tomotsuka Takayama : Professor, Disaster Prevention Research Institute Port and Airport Research Institute Dr. Shigeo Takahashi : Executive Researcher Dr. Tetsuya Hiraishi : Director, Wave Div. Mr. Hiroyasu Kawai : Director, Marine Hydraulics and Storm Surge Div. National Institute for Land and Infrastructure Management, Ministry of Land, Infrastructure and Transport Mr. Katsuya Oda : Director, Coastal Disaster Prevention Div. Coastal Development Institute of Technology Mr. Susumu Murata : President Mr. Yoshiji Koyano : General Manager, The First Research Dept. 4. Survey results Outline of the damage Hurricane Katrina that reached the mainland near New Orleans on August 29 triggered storm surges and high waves that caused severe damage along the coastlines of the states of Alabama, Mississippi, and Louisiana. The two major causes of the disaster can be pointed out: the storm surge on Lake Pontchartrain and the storm surge on the Gulf of Mexico ranging from Alabama to Louisiana. The former is the inundation of urban New Orleans caused by the breaking of the flood walls of the 17th Street Canal and the London Ave. Canal. The latter includes the inundation of the 9th Ward District and the port and industrial district caused by the overflow and breaching of the levee of the Inner Harbor Navigation Canal located in the east part of New Orleans. Most of this damage was 2
caused by the storm surge on the Gulf of Mexico including Lake Borgne, submerging the St. Bernard District in eastern New Orleans and the coastal land to its south and inflicting severe flood damage on a long coast extending from the State of Alabama to the State of Mississippi. In Japan, people are mainly aware of the inundation damage in urban New Orleans and the 9th Ward, but it should be noted that damage occurred over an extremely wide range and that the damage mechanisms differed. It is reported that the water level was raised from 3m to 3.5m by the storm surge on Lake Pontchartrain, and was raised extremely high, from 3m to 7m, by the storm surge from Alabama to Mississippi. No inundation from the Mississippi River was confirmed in this survey. Destruction and submersion of houses by run up and destruction and collapse of bridges by uplift pressure Lake Pontchartrain Inundation caused by breaking of flood walls New Orleans Mississippi Inundation caused by overflowing of a levee Lake Borgne Biloxi Long beach Inundation caused by overflowing of levees and high water River Figure 2. Outline of Inundation Damage by Katrina (Revised Disaster Map from the Federal Emergency Measures Agency) (1) Inundation disaster in urban New Orleans The water level on Lake Pontchartrain reached nearly the crown of the approximately 4m high canal levee but did not overflow it, and along the 17th Street Canal and the London Ave. Canal in urban New Orleans, the flood walls were broken by the water pressure. Photo 1 shows the site of the flood wall damage on the 17th Street Canal where houses were washed away or destroyed and the urban district was almost completely flooded. 3
Photo 1. Site of the Breach on the 17th Street Canal (2) Inundation damage near the Inner Harbor Navigation Canal in eastern New Orleans The Inner Harbor Navigation Canal in New Orleans is a man-made canal linked to the Gulf of Mexico and is surrounded by the port district and an industrial zone. Here, the storm surge on the Gulf of Mexico was transmitted so the water level exceeded the crown of the levee (approx. 4m) breaching it at 3 locations. Photo 2 shows the breach area in the 9th Ward. Photo 2. Site of the Breach in the 9th Ward (3) Inundation damage in the east and south area of New Orleans Lake Borgne is linked to the Gulf of Mexico, so in the east part of New Orleans (St. Bernard Parish) and along the coast to its south (Plaquemines Parish), the water level exceeded the crowns of the levees on the coastline and the canal, causing extremely severe damage. Photo 3 shows a barge that appears to be crossing the crest of the levee of the canal and houses that appear to be running up over a levee on the Mississippi River from Lake Borgne side. 4
Photo 3. Overflow Damage in St. Bernard and Plaquemines Parish (4) and high wave damage on the coastline of the states of Alabama and Mississippi On the coast from Long Beach to Gulf Shore (length of more than 100km), an extremely large storm surge from 3m to 7m and the high waves destroyed buildings as far as between 200 and 300m inland and inundated the ground as far as about 1km inland. Photo 4 shows locations where houses were destroyed and where a container carried from a nearby port collided with a house. Photo 4. Storm Surge and High Wave Damage Near the Coastline (5) Recovery and restoration of storm surge damage The drainage has been completed and people are returning, but Photo 5 shows a place where waste materials of many kinds have been discharged from formerly submerged houses and a site where this waste and the destroyed houses are collected. Not only is waste material and rubble being disposed of, but the water and electric power supply system are now being restored. 5
Photo 5. Waste Material from Submerged Houses and its Collection 5. Concluding Remarks We would like to express our deepest condolences to the affected people. There are many lessons we should learn from the disaster caused by Hurricane Katrina including the importance of considering the damage caused by this storm surge that exceeded design conditions, of considering the destruction of the disaster prevention structures and the resultant expansion of the damage, and of officials responsible for disaster prevention responding fully to such a disaster during and after it. This is a tentative report summarizing the results of the field survey. More detailed data will be organized and analyzed and further research will be carried out to reduce coastline damage in Japan based on the lessons taught by the disaster of Hurricane Katrina. We wish to express our deep gratitude to engineers and researchers from the Ministry of Land, Infrastructure and Transport Japan, universities in the U.S. and the U.S. Army Corps. of Engineers for their assistance with this survey. 6