Major Midwest flood risk underestimated by as much as five feet, study finds

Washington University in St. Louis Newsroom: As floodwaters surge along major rivers in the midwestern United States, a new study from Washington University in St. Louis suggests federal agencies are underestimating historic 100-year flood levels on these rivers by as much as five feet, a miscalculation that has serious implications for future flood risks, flood insurance and business development in an expanding floodplain.

“This analysis shows that average high-water marks on these river systems are rising about an inch per year — that’s a rate ten times greater than the annual rise in sea levels now occurring due to climate change,” said Robert Criss, PhD, professor of geology in the Department of E
arth and Planetary Sciences in Arts & Sciences and author of the study.

Published this month in an advance online issue of the Journal of Earth Science, the findings are important, Criss said, because many of the nation’s flood-control river levee systems are not engineered to withstand floods that rise much higher than the projected 100-year flood level. Any flood that rises even a few inches over the top of a 100-year levee has the potential to cause a catastrophic breach of the flood control system, he warns.

Based on complicated equations currently used by key federal agencies, such as the Federal Emergency Management Agency (FEMA) and the U.S. Army Corps of Engineers (USACE), the official 100-year flood level is a key national index of potential flood severity. Levees are commonly designed to withstand floods at “100-year” levels and “100-year” flood zones are delineated on detailed flood insurance maps produced by FEMA.

Criss, a hydrogeologist who has studied water flows on major rivers for decades, has long argued that man-made river control systems, such as levees, locks, dams and navigation-enhancing dikes, have gradually increased the odds of catastrophic flooding by tightly constricting river channels and preventing floodwaters from flowing naturally into surrounding wetlands and floodplains....

Jefferson Highway in Melville, Louisiana during the flood of 1927.

At least two killed as storms tear through Arkansas, Mississippi

Reuters: At least two people were killed as wild storms and suspected tornadoes tore through parts of Mississippi and Arkansas on Saturday, injuring several others, damaging homes and sweeping trucks off a highway, authorities said.

Two adults died when the car they were driving in struck a fallen tree in the road in Jasper County, Mississippi, county coroner Randy Graham told Reuters.

Local television reports said a man was killed in Coahoma County when his mobile home blew over in high winds, but authorities could not be reached for confirmation early on Sunday.

Widespread damage from the storm system was also reported near Dermott, Arkansas, in the southeast corner of the state, where five homes were badly damaged, 15 suffered minor damage and four trucks were blown off a highway, said National Weather Service meteorologist David Cox in Jackson, Mississippi. Two people were injured, he said….

FEMA photo of damage from a 2001 tornado near the Arkansas-Mississippi border

Tropical Storm Karen continues move toward northern Gulf Coast

Kevin Mcgill and Stacey Plaisance in ABC News via Associated Press: Tropical Storm Karen continued chugging toward the northern Gulf Coast on Saturday, with forecasters predicting rain, potential flooding and a decrease in speed later in the day.

The National Hurricane Center reported early Saturday that Karen's maximum sustained winds had dropped to 40 mph, making it a weak tropical storm. It was moving north at 10 mph (16 kph), and center forecasters said in their advisory that they expect Karen to decrease in speed later Saturday and turn toward the northeast.

A tropical storm warning is in effect from Morgan City to the mouth of the Pearl River, which forms part of the border between Louisiana and Mississippi. A tropical storm watch covers the New Orleans area and a stretch from east of the Pearl River's mouth to Indian Pass, Fla.

Forecasters expect the storm's center to be in the warning area Saturday night or Sunday morning, and they note that an increase in speed is possible Sunday. Rain accumulations of 1 to 3 inches over the central Gulf Coast and southeastern U.S. are possible through Monday night, with isolated totals up to 6 inches.

At the hurricane center in Miami, forecasters said the storm no longer had a chance of strengthening into a hurricane. Karen began losing some of its punch late Friday, after a busy day of preparations along the Gulf Coast for the storm. Karen is a late-arriving worry in what had been a slow hurricane season in the U.S. Karen would be the second named storm to make landfall in the U.S. — the first since Tropical Storm Andrea hit Florida in June....

Tropical Storm Karen on October 3, 2013, shot by NASA

Quantifying sediment from 2011 flood into Louisiana's wetlands

Space Daily via SPX: The spring 2011 flood on the Mississippi was among the largest floods ever, the river swelling over its banks and wreaking destruction in the surrounding areas. But a University of Pennsylvania-led study also shows that the floods reaped environmental benefits - transporting and laying down new sediment in portions of the Delta - that may help maintain the area's wetlands.

The study, led by Ph.D. student Nicole Khan of the Department of Earth and Environmental Science, is the first to quantify the amount of sediment transported to wetlands by a flood on the Mississippi. The results shed light on how floods impact wetlands, and how these effects might be harnessed to purposefully rebuild Louisiana's wetlands, which are sinking from compaction and growing smaller as sea level rises.

...A study by many of the same scientists, published in Nature Geoscience last year, found that the 2011 Mississippi River floods deposited more sediment in the Atchafalaya River Basin, where the waters moved slowly over a broad area, than in the Mississippi River Basin, where levees and control structures funneled the floodwaters into a jet stream that shot water and sediment out into the Gulf of Mexico.

The current study, published in Geology, focuses specifically on the questions of how much sediment was laid down in the river basins affected by the flood and where the sediments deposited the most.

"The marshes may be able to maintain their surface area or height above sea level if they receive significant sediment, either from floods or hurricanes or normal fluvial processes," Horton said. "Ours is the only empirical study to obtain an estimate of how much sediment is deposited by a large-scale flood on the Mississippi."...

A barge on the Mississippi in Louisiana, shot by Ken Lund, Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license

Mississippi river faces shipping freeze as water levels drop

Suzanne Goldenberg in the Guardian (UK): The worst drought in half a century has brought water levels in the Mississippi close to historic lows and could shut down all shipping in a matter of weeks – unless Barack Obama takes extraordinary measures. It's the second extreme event on the river in 18 months, after flooding in the spring of 2011 forced thousands to flee their homes.

Without rain, water levels on the Mississippi are projected to reach historic lows this month, the national weather service said in its latest four-week forecast. "All the ingredients for us getting to an all-time record low are certainly in place," said Mark Fuchs, a hydrologist at the National Oceanic and Atmospheric Administration (Noaa) in St Louis. "I would be very surprised if we didn't set a record this winter."

The drought has already created a low-water choke point south of St Louis, near the town of Thebes, where pinnacles of rock extend upwards from the river bottom making passage treacherous. Shipping companies are hauling 15 barges at a time instead of a typical string of 25, because the bigger runs are too big for current operating conditions.

Barges are being sent off with lighter loads, making for more traffic, with more delays and back-ups. Stretches of the river are now reduced to one-way traffic. A long cold spell could make navigation even trickier: shallow, slow-moving water is more likely to get clogged up with ice.....

Barges in the Mississippi near St. Louis, shot by Paul Sableman, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

Isaac officially reaches hurricane strength

CBS News: Isaac officially ballooned into a hurricane Tuesday that could flood the coasts of four states with storm surge and heavy rains on its way to New Orleans, where residents hunkered down behind levees fortified after Katrina struck seven years ago this week.

Shelters were open for those who chose to stay or missed the chance to get away before the outer bands of the large storm blow ashore ahead of a forecast landfall in southeast Louisiana on Tuesday night or early Wednesday.

Forecasters warned that Isaac was a large storm whose effects could reach out 200 miles from its center. Water may be worse than wind because the storm could push walls of water while dumping rain to flood the low-lying coast in Louisiana, Mississippi, Alabama and the Florida Panhandle.

The U.S. National Hurricane Center in Miami upgraded Isaac to a Category 1 hurricane midday Tuesday, with surface wind speeds of 75 mph and flight-level winds even stronger, at 110 mph. The storm system was centered about 75 miles south-southeast of the mouth of the Mississippi River at 12:20 p.m. ET and was moving northwest at 10 mph, according to the National Hurricane Center in Miami. It was 160 miles southeast of New Orleans.

CBS News hurricane consultant David Bernard reports from CBS station WFOR-TV in Miami that some areas hit by Isaac could see as much as 20 inches of rain. In Washington, President Obama urged Gulf Coast residents to listen to local authorities, saying in brief remarks at the White House that "now is not the time to tempt fate."

The president declared a state of emergency in Louisiana late Monday, more than 24 hours before the storm was expected to hit the Gulf Coast. The declaration makes federal support available to save lives, protect public health and safety and preserve property in coastal areas....

GUANTANAMO BAY, Cuba (Aug. 23, 2012) Employees of Bremcor, a military contracting company, tie down geo-fabric netting that surrounds the detainee camps at Guantanamo in preparation for Tropical Storm Isaac.

Low water strands 97 vessels on Mississippi River

Karl Plume in Reuters: The U.S. Coast Guard said on Monday that 97 vessels were stranded by low water on the Mississippi River near Greenville, Mississippi, after it closed an 11-mile stretch of the drought-parched waterway for dredging and to replace missing navigation buoys.

The worst U.S. drought in 56 years has left the river there at its lowest point since 1988, a year when a similarly dire drought also stalled commercial traffic on the major shipping waterway.

Further north, dredging operations near St. Louis were halting river traffic for 12 hours at a time as the U.S. Army Corps of Engineers worked to keep a shipping lane wide enough and deep enough for commercial barge tows hauling everything from grain and fertilizer to steel and coal, industry sources said.

Shippers have been told for weeks to limit the amount of cargo loaded onto barges by at least 30 percent so that they sit higher on the water, and to limit the number of barges in tows, but numerous vessels have still run aground up and down the river....

Barges on the Mississippi, shot by Ken Lund, Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license

Drought sends Mississippi into 'uncharted territory'

John Yang of NBC News: The drought of 2012 has humbled the mighty Mississippi River. A year after near-historic flooding, the river’s water levels are at near-historic lows from Cairo, Ill., where the Ohio River empties into it, to New Orleans, just north of its endpoint at the Gulf of Mexico.

In July, water levels in Cairo, Memphis, Tenn., and Vicksburg, Miss., dipped below those of the historic drought of 1988. That’s affecting everything from commerce on the maritime superhighway to recreation to the drinking water in Louisiana.

The biggest impact may be on shipping. “It’s getting near critical,” said Austin Golding, a third-generation co-owner of Vicksburg, Miss.-based Golding Barge Lines. “Without more rain, we’re heading into uncharted territory.”

About $180 billion worth of goods move up and down the river on barges, 500 million tons of the basic ingredients for much of the U.S. economy, according to the American Waterways Operators, a trade group. It carries 60 percent of the nation’s grain, 22 percent of the oil and gas and 20 percent of the coal, according to American Waterways Operators. It would take 60 trailer trucks to carry the cargo in just one barge, 144 18-wheeler tankers to carry the oil and gas in one petroleum barge.

The low water levels mean that barge companies have to lighten their load by about 25 percent so the barges ride higher in the water, reducing what’s known as the barges’ “draught.”  That means each tow boat is moving less cargo than usual even though “it takes up the same amount of fuel to burn and the same amount of manpower,” said Ed Henleben, senior operations manager for Ingram Barge Co. in St. Louis....

Coal barges on the Mississippi, shot by Paul Sableman, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

Tornadoes' death toll mounts; rescue efforts underway

Jessie Halladay and Doyle Rice in USA Today: A series of tornadoes that cut a swath of death and destruction across at least 10 states left stunned residents digging through rubble Saturday, looking for survivors and bodies.

The death toll stood at 31 early Saturday, including 14 Indiana, 13 in Kentucky, three in Ohio and one in Alabama. Tornadoes also were reported in Mississippi, Tennessee, Illinois, Georgia, North Carolina, and Virginia.

Massive thunderstorms threw off scores of tornadoes, crushing entire blocks of homes, ripping down power lines and tossing cars, buses and trucks on roadways made impassable by debris. The scale of the devastation and the breadth of the storms made it impossible to immediately assess the storm system's damage.

At least four people were killed in and around the town of Chelsea in Jefferson County, Ind. First responders found a 4-year-old boy and his great-grandparents lying on the ground 50 feet from where the elderly couple's home was blown off its foundation and thrown more than 100 feet. "All of this happened in less than 30 seconds," said volunteer firefigthter Cory Thomas.

In Marysville, Ind., most of the several dozen homes that make up the town were destroyed. "Marysville is completely gone," Clark County Sheriff's Maj. Chuck Adams said.

Kentucky declared a state of emergency, and Indiana officials said they were discussing that. Authorities in Ohio planned to survey areas Saturday to determine the extent of the damage there....

February 29, 2012. a view of where a church used to stand in Harrisburg, Illinois, on U.S. Route 45 at south corner with Illinois Route 34 and Illinois Route 145, adjacent to the United States Forest Service office. Shot by Pat York, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

No consistent declines in nitrate levels in large rivers in the Mississippi River Basin

US Geological Survey: Despite efforts to reduce nitrate levels in the Mississippi River Basin, concentrations and transport at eight major study sites did not consistently decline from 1980-2008. These results are based on a new scientific model developed by the USGS that takes into account variation in river flows in order to gain an accurate understanding of long term trends. The results of the new USGS study are published in the journal Environmental Science and Technology.

“While conservation practices may have decreased nitrate levels in some portions of the basin, we aren't seeing widespread effects at larger scales,” said Lori Sprague, USGS hydrologist and lead author on the report. “Applying this new model to decades of USGS water quality data allows us to distinguish between the effects of natural changes in precipitation and streamflow and the effects of purposeful changes in the management of nitrate in the basin.”

Excessive nutrients like nitrate in the Mississippi River Basin contribute to hypoxia, or dead zones, in the Gulf of Mexico. The dead zones are the result of too little oxygen to support most marine life in bottom and near-bottom water. State and federal partners serving on the Mississippi River Gulf of Mexico Watershed Nutrient Task Force are striving to decrease nutrients transported to the Gulf to reduce the size of the hypoxic zone to less than 5,000 square kilometers (about 2,000 square miles) by 2015.

For this new study, the USGS analyzed data from eight study sites taken between 1980-2008, including 3,368 individual water-quality samples and 110,732 individual daily streamflow values. Major Findings:

• Nitrate transport to the Gulf of Mexico was 10% higher in 2008 than 1980. Nitrate transport during the spring is one of the primary determinants of the size of the Gulf hypoxic zone....
• Nitrate concentrations increased considerably at two sites with low concentrations in 1980...
• Nitrate concentrations remained the same or increased at the other six sites, including those where concentrations were relatively high in 1980. On the Iowa River at Wapello, Iowa, Illinois River at Valley City, Ill., and Ohio River near Grand Chain, Ill., nitrate concentrations were virtually unchanged. Along the Mississippi River at Grafton, Ill., and Thebes, Ill., and near the Old River Outflow Channel in Louisiana near where the Mississippi River enters the Gulf of Mexico, concentrations increased 10-20%.
• Increases in nitrate concentrations in groundwater are contributing to increases in river concentrations. At most sites, increases in nitrate concentrations at low and moderate streamflows were greater than or comparable to changes at high streamflows. These results suggest that increasing nitrate concentrations in groundwater are having a substantial effect on nitrate concentrations in rivers and transport to the Gulf. Because nitrate moves slowly through groundwater to rivers, the full effect of management strategies designed to reduce nitrate movement to groundwater may not be seen in these rivers for many years....

Aerial view of the waterfront section of Cape Girardeau, Missouri, USA, along the River. The picture was taken during the flood of 1993. The floowalls built by the U.S. Army Corps of Engineers are protecting the city from flooding. This picture was taken before the new bridge across the Mississippi was built in 2003. US Army Corps of Engineers photo

2011 dead zone in Gulf of Mexico could be the biggest ever

Texas A&M University News and Information Service: Researchers from Texas A&M University have returned from a trip to examine the scope and size of this year’s “dead zone” in the Gulf of Mexico and have measured it currently to be about 3,300 square miles, or roughly the size of Delaware and Rhode Island combined, but some researchers anticipate it becoming much larger.

Oceanography professor Steve DiMarco, one of the country’s leading authorities on the dead zone, says the team of researchers journeyed more than 1,400 miles throughout the Gulf over a five-day period, the first ever focusing on the month of June.

DiMarco says the size of the dead zone off coastal Louisiana has been routinely monitored for about 25 years. Previous research has also shown that nitrogen levels in the Gulf related to human activities have tripled over the past 50 years. During the past five years, the dead zone has averaged about 5,800 square miles and has been predicted to exceed 9,400 square miles this year, which would make it one of the largest ever recorded, according to the Louisiana Universities Marine Consortium. (http://gulfhypoxia.net/)

Hypoxia occurs when oxygen levels in seawater drop to dangerously low levels, and severe hypoxia can potentially result in fish kills and harm marine life, thereby creating a “dead zone” of life in that particular area.

Because of record amounts of water flowing from the Mississippi River into the Gulf, there is keen interest in the dead zone areas this year, DiMarco explains, adding that the size of this year’s dead zone could still change because large amounts of water are still flowing into the Gulf of Mexico from the Mississippi River.

…“The largest areas of hypoxia are still around the Louisiana coast, where you would expect them because of the huge amounts of fresh water still coming down from the Mississippi River,” he adds.“The hypoxic area extends about 50 miles off the coast. The farther you go west toward Texas, there is still hypoxia, but less severe. However, we did see noticeable hypoxia near the Galveston area.”…

The Mississippi Delta from space in 1976, via NASA

Landsat 5 satellite sees Mississippi River floodwaters lingering

NASA: In a Landsat 5 satellite image captured June 11, 2011, flooding is still evident both east and west of the Mississippi River near Vicksburg, Miss. Standing water is most apparent, however, in the floodplain between the Yazoo and Mississippi rivers north of Vicksburg.

On May 19, 2011, the Mississippi River reached a historic crest at Vicksburg. According to the Advanced Hydrological Prediction Service (AHPS) of the U.S. National Weather Service, the river reached 57.10 feet (17.40 meters) that day. By early June, flooding had receded considerably around Vicksburg, but water remained high.

On June 14, the AHPS reported that the Mississippi River reached 44.88 feet (13.68 meters) at Vicksburg. At that point, the river was in minor flood stage, and its level was forecast to continue falling through June 19.

The Landsat series of satellites is used by emergency managers to acquire a range of imagery, from floods to fires. Landsat has recently provided both images of the flooding of the Mississippi River and the fires raging in Arizona…

The Landsat 5 satellite Thematic Mapper captured these images on June 11, 2011 (left) and June 18, 2008. In these false-color images, water is navy blue. Depending on land use, land above water is green or burnt orange. The images are rotated, with the left sides facing north. (Credit: NASA Earth Observatory images created by Jesse Allen and Robert Simmon, using Landsat data provided by the United States Geological Survey)

What will insurance pay?

Jeff Ayres in the Reno Gazette-Journal.com: Scores of Mississippians should get a better sense in coming weeks of whether their insurance policies can help them recover from flood-related damage - and what those policies won't cover. The latter is important because private insurers generally don't offer flood coverage for homeowners, says state Insurance Commissioner Mike Chaney.

That leaves the National Flood Insurance Program, administered by the Federal Emergency Management Agency, as the primary option for people whose homes have suffered flood damage. Because water remains high in a number of areas, the number of flood-related claims filed or expected to be filed in the state for homes, businesses and crops haven't been determined.

As of March 31, the most recent date for which figures are available, there were 75,174 NFIP policies in effect in Mississippi, according to FEMA. But Chaney estimates less than half of those in flooded areas along the Mississippi and Yazoo rivers have some type of flood coverage. "Most of them (have) low-income houses, and (people) just move on and try to rebuild," he said, adding they often can't afford flood insurance….

Tunica Riverpark and Museum at Tunica Resorts in Tunica County, Mississippi, with a barge passing by on the Mississippi River. Shot by Thomas R Machnitzki, under the Creative Commons Attribution 3.0 Unported license

As Mississippi River recedes, flood warning lifted for New Orleans

John Pope in the Times-Picayune: Based on a drop in the level of the swollen Mississippi River, the National Weather Service on Friday canceled its weeks-long flood warning for New Orleans and points downriver. Despite this development for south Louisiana, the weather service’s flood warning remains in effect for points upriver, including Baton Rouge, where levee seepage has led the state Office of Transportation and Development to close River Road’s southbound lane from North Third Street to State Capitol Drive.

In New Orleans, the river’s flood stage is 17 feet, but the weather service saw no reason to maintain the flood warning as the Mississippi’s level dropped to 16.8 feet, where it is expected to stay through Monday before dropping another 0.1 foot on Tuesday, said Jeff Graschel, service coordination hydrologist for the weather service.

There are several reasons for the change, he said, including falling levels upstream and the Bonnet Carre and Morganza spillways’ ability to divert some of the flow. As a result of these factors, Graschel said, “we’re going to keep (the water level) right below flood stage.” The levee system in New Orleans protects the city from water levels as high as 20 feet….

In New Orleans, some levee repair post-Katrina in the Industrial Canal, shot by Stephen Marchetti, Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license

Flood damage vexes Tennessee residents

John Pape in Disaster News Network: While much of the focus on the Mississippi River flooding is on the crest as it moves downstream into Louisiana, the recovery has begun in upstream areas like Memphis. Assessment teams from federal and state agencies, working with volunteers from a host of faith-based organizations, have begun to determine how much work will needed to rehabilitate the more than 700 homes that have been classified as “uninhabitable” after being inundated by floodwaters.

Still, recovery officials said, many parts of the Memphis area remain under water and the full extent of the damage will probably not be known for several more weeks. In its latest update, the Shelby County Office of Preparedness said both the City of Memphis and the county were only beginning the process of assessing the level of damage sustained by the flooding. In many cases, roads are still flooded.

“The Mississippi River and its tributaries will remain high for several more days. This will slow down the clean-up effort and prolong traffic delays,” the county said in a statement. “Many streets and intersections are closed because of high water.”…

NASA image of flooded Memphis, May 10 2011

Americans take a gamble with the Mississippi floods

Suzanne Goldenberg in the Guardian (UK) describes a deeply ingrained US tendency to ignore risk. Since preventing development in dangerous areas rarely has much standing on the nation's agenda, we keep making the same mistake for the sake of short-term gain: …Seen one way, the floods are an act of nature, beyond human control – and America got off relatively lightly. Despite extensive property damage, with predictions that more than a million acres of land would go underwater, only four deaths due to flooding have been recorded so far, in Arkansas and Mississippi. Industries, population centres and shipping in the Mississippi have been protected. Unlike in Hurricane Katrina, the Army Corps of Engineers, which is in charge of flood control, has had no levee failures.

Looked at another way, the flooding was entirely predictable. Damage to homes and fields in the Mississippi's way should have been avoidable. For all the effort over the years put into controlling the Mississippi, for many individuals – and even entire towns – there is only the illusion of safety.

…There is complacency and resignation. Flood experts argue that America's flood protection standards are lax compared with those in other countries. Authorities have hesitated to relocate people to safer ground, or to enforce laws that compel local authorities to provide flood protection and require homeowners to get flood insurance.

"We have been very good at letting people continue to live in harm's way," said George Galloway, who was commander of the Army Corps at Vicksburg in the 1970s. "But how much longer can we continue to do that since we know with climate change we are going to have more floods than in the past?" In the 1990s, Galloway led a White House study into improving flood protection. It concluded that most people living in flood areas – up to 7 million across the country – did not fully understand the risks they faced.

…It is becoming evident that the Army Corps of Engineers and other forecasters have underestimated the frequency of severe flooding along the Mississippi. "We had a 500-year flood in 1993, a 70-year flood in 2001, and a 200-year flood in 2008. What blows my mind is that I just published this paper in 2008 and every year since then we have had another 10-year flood," said Robert Criss, a hydrologist at Washington University in St Louis. "The observed frequency of flooding is completely incompatible with the Army Corps estimates."…

The Great Mississippi Flood of 1927, Greenville, Mississippi. The river stage was at 46.8 feet. From: "The Floods of 1927 in the Mississippi Basin", Frankenfeld, H.C., 1927 Monthly Weather Review Supplement No. 29.

Climate change blamed for record Mississippi floods

Environment News Service has a story that about scientists explicitly stating the obvious about making the climate change component in the recent floods in the US. Let's see more of this!: Human-induced climate change is contributing to the recent heavy rain and ongoing record flooding along the Mississippi River, and we can expect more extreme weather events in the future, according to scientists and adaptation experts on a teleconference held by the Union of Concerned Scientists.

"Climate change is about more than warming. What we're really seeing is global weirding," said climate scientist Katharine Hayhoe, associate professor at Texas Tech University. "It is altering the character and conditions of the places we know and love. For many places around the world, what we are likely to see could be feast or famine - more frequency of weather at the extremes, from intense storms to prolonged droughts." "We can't attribute any one event to climate change," she said, "but we do know that every event that happens is already superimposed on very different background conditions than we had 50 years ago."

Economic losses from natural disasters have soared from a global average of $25 billion annually during the 1980s to $130 billion a year during the decade ending in 2010, said Nikhil da Victoria Lobo, senior client manager in the Global Partnerships team at Swiss Re, an international reinsurance firm. He told reporters that there's little doubt that "climate volatility was a major contributor," although he says it is impossible to estimate what percentage of losses were due to climate change.

Swiss Re is working with local governments around the world to help them bear less of the burden for costs associated with extreme weather. "We live in a world where rising budget deficits are being coupled with extreme weather events that further aggravate these financial burdens," he said. "However, insurance can put a price tag on climate risk, and help local governments more efficiently prepare for and finance what may happen."

Local governments must now determine what municipal infrastructure is vulnerable to future extreme weather and what capital investments will best protect residents and property….

From 1903, "Mule teams on the levee, New Orleans, La." Shows temporary emergency levee along the riverfront during the Mississippi River flood of the spring of 1903. Jackson Brewery building seen at right. Rice mill and sugar refinery further upriver. Boxcars seen on railine at right, labeled "Texas & Pacific", "A&V" (Alabama & Vicksburg) and "SICL" (Southern Iron Car Line)

Letting Mississippi run its natural course could save New Orleans from hurricanes

William Sargent in the Christian Science Monitor analyzes the stark long-term choices faced by everyone living in and near the Mississipi Delta: During the next few days the Army Corps of Engineers must continue making their Hobbesian choice between the ultimate disaster for New Orleans and an $18 billion bet that they can beat Mother Nature. To keep flood waters from breaking the levees and charging into the city, the Corps is making an $18 billion gamble that they can divert a fourth of the Mississippi’s flow down the Atchafalaya River without losing control of the situation.

The choice may seem obvious, but the Corps’ gamble also holds potentially devastating consequences for New Orleans. If it loses control of the diversion, the entire flow of the Mississippi could suddenly come thundering down the Atchafalaya – the course nature wants it to follow – never to be diverted back. Farms, towns, and oil refineries would be drowned, and the key port cities of New Orleans and Baton Rouge would be left without their river.

As the Corps begins the partial diversion of the Mississippi down the Atchafalaya, coastal scientists should seize on the opportunity to consider longer-term shifts in the river’s course. It’s possible that this crisis could lead to a less costly and more sustainable way of dealing with the problems of coastal Louisiana.

Although such a shift in the river’s path would deal a devastating economic blow to the region, allowing the Mississippi to flow west down the Atchafalaya would ultimately be in the best long-term ecological interest of the area because it would build up the southern Louisiana coast as a buffer against future hurricanes.

… For thousands of years, the Mississippi River has naturally writhed back and forth like a water hose, spewing muddy sediment loads first one place then another along several hundred miles of coast. These movements built up a number of major deltas along the southern Louisiana coast.

This shifting geography has gradually reoriented the course of the river. Now the river is running about as far east as it can possibly go, and it wants to writhe back west, away from New Orleans and down the Atchafalaya River Basin instead.

But in the late 1950’s, Congress passed a bill to save the port of New Orleans by making it illegal for more than a third of the Mississippi to flow down the Atchafalaya River basin. This is akin to passing a bill to hold back the tide….

Water is flowing through bays at the Morganza floodway, May 14, 2011. (U.S. Army Corps of Engineers photo)

Rural Louisiana has mixed feelings over flooding plan

Greg Flakus in Voice of America: As diverted water from the swollen Mississippi River flows through Louisiana's Morganza spillway and into the Achafalaya basin on its way to the Gulf of Mexico, thousands of people in the southern state are losing their homes, businesses and crops. The U.S. Corps of Engineers opened the spillway recently to protect the cities of Baton Rouge and New Orleans from major flooding. People in the flood plain, however, are paying a high price.

As the flood waters pour into the woods, fields and small towns along the Achafalaya River, people and wildlife are pouring out of the region, seeking higher ground. Many towns closer to the source of the water, the Morganza spillway, are already evacuated. The spillway was partially opened by the U.S. Corps of Engineers to relieve the rush of flood water on the Mississippi River that could devastate the state capital of Baton Rouge and the historic port city of New Orleans farther downstream.

In La Fourche Parish, in southern Louisiana, local officials are counting on levees as high as one-and-a-half meters to hold back flood waters, but some rural areas and homes outside the system likely will be inundated.

Parish spokesman Brennan Matherne said people there are not happy about the coming flood, but that most of them accept the decision made by the Corps of Engineers to flood their region rather than the much more populated urban areas.

“I think there is definitely mixed feelings," said Matherne. "I think most people who have settled here understood that they were building in a flood plain. I mean, we deal with disasters, unfortunately, almost on an annual basis - whether it be hurricanes, flooding or oil spills such as what happened last summer.”…

A 1999 photo by the Army Corps of Engineers of the Old River Control Structure at the juncture of the Mississippi River and the Atchafalaya River. In this photograph, the Mississippi River runs along the left and curves away to the right in the distance. The Atchafalaya River meets the Mississippi at three points and runs off to the bottom right. Control structures (dams) at each of the three forks of the Atchafalaya prevent most of the waters of the Mississippi from running into the Atchafalaya.

Morganza Spillway opens, residents evacuate

Janis Easch in Third Age: After the Morganza Spillway was opened this weekend, thousands of residents of Louisiana towns along the Mississippi River were evacuating and many tried to protect their homes from rising waters, officials said.

… Many residents were forced to evacuate because of a government decision to divert water from the Mississippi into south central Louisiana to spare the cities of Baton Rouge and New Orleans from severe flooding. The U.S. Army Corps of Engineers opened floodgates at the Morganza spillway, diverting water to Louisiana's Atchafalaya Basin. Early Monday, the corps opened nine gates, agency spokesman Ricky Boyett said.

The plan is to release water from as many as a quarter of the spillway's 125 bays. The controlled release lowered projected flood levels for five communities where the corps maintains monitoring gauges, including Baton Rouge and New Orleans, 115 miles southeast of the spillway, CNN reported, But the decision may affect nearly 4,000 people who live along the river in the Atchafalaya Basin, Louisiana Gov. Bobby Jindal said.

Authorities in Louisiana's St. Landry Parish issued a mandatory evacuation order that affected about 2,000 people, CNN reported. Residents in other areas were under a voluntary evacuation, with authorities encouraging but not ordering them to leave. Floodwaters were expected to cut a path about 20 miles wide that will flow down the Atchafalaya Basin in the coming days, from Morganza, La., to the Gulf of Mexico, Gannett News Service said…

The Morganza Spillway in 1973, US Army Corps of Engineers photo