U.S. GEOLOGICAL SURVEY LOUISIANA WATER SCIENCE CENTER ASSESSMENT OF THE IMPACTS OF HURRICANE KATRINA IN LOUISIANA

Hurricane Katrina made landfall on the coast of Louisiana near Buras, Louisiana as a category 4 hurricane during the early hours of August 29, 2005. The storm crossed the Mississippi River Delta, and Mississippi Sound, and came back ashore near the Louisiana-Mississippi border. Winds as high as 140 mph were recorded in the near shore areas of Louisiana and Mississippi. The U.S.Geological Survey Louisiana Water Science Center (LWSC) coastal gages in Barataria Bay, Breton Sound, and the Lake Pontchartrain Basin were monitored throughout the storm at the Louisiana Office of Emergency Preparedness storm command center. These gages provided critical information used in the closure of highways as the storm came ashore. Twenty-three gages were destroyed as a result of the high winds and storm surge from Katrina. The USGS LWSC lost communications and Internet access for almost three weeks following the storm resulting in the immediate activation of back-up sites for real time gage data, and 2 days later, the National Water Information System

Staff from the LWSC deployed to New Orleans August 30 to September 1 for search and rescue operations. Concerns about potential water-quality issues prompted discussions among the U.S. Environmental Protection Agency (EPA), Louisiana Department of Environmental Quality (LDEQ), and the LWSC to coordinate sampling locations and constituents sampled. The LWSC sampled fecal-indicator bacteria in Lake Pontchartrain in support of the LDEQ monitoring effort and water and bed-sediment samples from those areas in the lake not sampled by LDEQ. Dewatered sediments deposited by floodwaters were sampled in New Orleans and St. Bernard Parish as floodwaters retreated to determine what chemicals were in these sediments. At the same time, staff continued to collect high water marks along the north shore of Lake Pontchartrain, and in St. Bernard and Plaquemines Parishes.

LWSC staff also deployed to the impacted Parishes to begin the process of rebuilding the monitoring network. Six temporary real-time water-level gages were installed in New Orleans, St. Bernard, and Plaquemine to assist the U.S. Army Corps of Engineers in determining how the city and flooded parishes were dewatering. Similarly, key gages on Lake Pontchartrain were given the highest priority for reinstallation to evaluate how long the lake would continue to flood the city following the breach in the canal walls. Additional water-quality and fecal-indicator bacteria samples were collected in coordination with LDEQ and the Louisiana Geological Survey from selected shallow ground-water wells on the north shore of Lake Pontchartrain to determine if shallow ground-water resources were adversely affected by the storm surge. The USGS mobilized crews from Arkansas, Ohio, and Texas to assist the USGS LWSC in assessing the impacts of Hurricane Katrina.