US 2015-2016 Midwest Winter Floods

Update 1 | Summary
Posting Date: January 7, 2016, 2:30:00 PM

A gradual realignment of the large-scale pattern over North America caused widespread storminess, including flooding rains, severe thunderstorms, and tornadoes, across most of the Midwest during the Christmas week. Record-breaking warmth combined with a moist air mass across the eastern and southern U.S. was displaced by a strong closed off upper-level low over Oklahoma. Accompanied by a surface low moving into Missouri, the strong system generated heavy rains and severe thunderstorms across the Midwest and Southeast of the U.S. The storm brought heavy rains to eastern Oklahoma, northwest Arkansas, and southwest Missouri, with 10.0 inches falling in a 30-hour period ending Sunday evening, December 27, on the south side of Springfield, Missouri. The Mississippi, Meramec, and Missouri rivers rose to flood stage at nearly 450 river gauges. Major flooding is impacting Missouri and Illinois, and even Arkansas, with further downstream impacts expected in Tennessee, Mississippi, and Louisiana.

Comparison to Historical Floods
Many have compared the Midwest Winter floods of December 2015-January 2016 to the floods of 1993 and 2011. The difference lies in the timing and duration. In 1993, severe flooding began in May on the Redwood River in Minnesota, and then in June 1993 on the Black River in Wisconsin. Next, record flooding was observed on the Mississippi, Missouri, and Kansas rivers. The most severe flooding was concentrated along a 500-mile stretch of the Mississippi River between Cairo, Illinois, and Minneapolis, Minnesota, and along a 400-mile length of the Missouri River from Omaha, Nebraska, to St. Louis, Missouri. Some sections of the Mississippi River were above flood stage from late March through most of August 1993. Overall economic damage estimates exceeded USD 15 billion (in 1993 dollars), by far the greatest flood loss in U.S. history. One third of the damage was to agriculture. Although the 2011 flood was shorter in duration, lasting from April to May, flood levels were higher in some locations. The economic damage was a few billion in 2011 dollars.

In contrast, floodwaters for the current situation have risen and fallen relatively quickly—lasting days rather than months—and the 2015 corn and soybean crop has been harvested, while the planting season for these crops is months away. Floodwaters are already receding in some parts of Missouri and Illinois, but not without having set records in some towns, such as Cape Girardeau and Thebes, Missouri. At Thebes, the Mississippi crested at 47.74 feet on January 2, the highest level ever observed; the crests in May 2011 and August 1993 at this gauge were 45.52 and 45.51 feet, respectively. At Cape Girardeau, the river reached 48.6 feet, surpassing the previous record of 48.89 feet set in August 1993.

Dozens of deaths have been attributed to the flooding; most were caused by drowning in vehicles that were swept away by the floodwaters. Hundreds of water rescues from homes and vehicles were carried out. Thousands were evacuated from their homes.

Missouri Governor Jay Nixon requested a federal emergency declaration to speed debris removal, which President Obama granted on January 2, and efforts to clear what is estimated to be as much as 500,000 tons of debris are under way. On the evening of January 5, Governor Nixon estimated that more than 7,000 structures in the St. Louis region were damaged by flooding. The St. Louis area was particularly hard hit, as it is a city where three major tributaries—the Illinois, Meramec, and Missouri rivers—meet the Mississippi. In St. Louis County, 900 homes and businesses were damaged, according to officials. Jefferson County has reported that 44 homes were destroyed, 975 have experienced major damage, and 308 minor damage. Franklin County has reported that 40 homes have been destroyed, 33 have experienced major damage, and 23 minor damage. Greene County has received reports of 630 homes and 16 commercial buildings damaged. Sections of Interstate 44 and Interstate 55 that had closed due to flooding have since been reopened. The flooding also disrupted travel on state roads, as well as by rail and ferry, for days.

The Governor of Illinois, Bruce Rauner, has issued a disaster declaration for 23 counties. There are eight river gauges still at major flood stage in Illinois. The river crested in Cairo at 56 feet on January 3 but remains in major flood stage there. On January 5, the U.S. Army Corps of Engineers stated that “all preparatory actions for operation of the Birds Point-New Madrid floodway have been put on hold.” The Mississippi broke through a levee in Thebes, Illinois, on Saturday, January 2, flooding areas as far as six miles inland. Some cities, such as Miller City and Fayville, were completely cut off as a result, but no deaths or injuries were reported. Local emergency management agencies are scheduled to provide damage assessments to the state on January 18.

Downstream Impacts Ahead
Towns along the Mississippi and its tributaries in Arkansas, Tennessee, Mississippi, and Louisiana are anticipating flooding in the days to come. In Arkansas, river gauges at Osceola on the Mississippi and at Des Arc on the White River are at major flood stage already. Towns from Arkansas City, Arkansas, to Baton Rouge, Louisiana, and the communities of Greenville, Vicksburg, and Natchez, Mississippi are preparing for major flooding.

The Governor of Louisiana, Bobby Jindal, declared a state of emergency in anticipation of the imminent threat of flooding downstream on the Mississippi and Red rivers. The Army Corps of Engineers stated on Monday, January 4, that if the “project-design flow of 1.25 million cubic feet per second (cfs), coinciding with a 17-foot stage, in the greater New Orleans area” occurred that “the Corps has the capability to regulate the amount of water flowing through the city by operating the Bonnet Carré Spillway to safely divert up to 250,000 cfs of water into Lake Pontchartrain.” On Tuesday, the commander of the ACE New Orleans District office recommended opening this spillway on Saturday, January 9.

In addition, “upriver from Baton Rouge, the Morganza floodway control structure [Morganza Spillway] could be operated if river levels reach 57 feet at the structure and there is a 10-day forecast indicating a Mississippi River flow of 1.5 million cubic feet per second and rising past the structure.” The opening of the Morganza Spillway in Pointe Coupe Parish could divert floodwaters away from Baton Rouge but could lead to the flooding of 800 homes in Butte La Rose. During the Mississippi River flood in 2011, the Army Corps of Engineers opened several flood gates on the Morganza Spillway for the first time in 37 years to relieve the downstream pressure.

The Army Corps of Engineers began daily inspections of Mississippi River levees in Louisiana on January 7. These inspections will continue through the beginning of February, as the river is forecast to be at the official flood stage of 17 feet through February 3.

Impact to Industry and Exposure
Since 1993 there has been a great reduction of exposures within and near the floodplains of the Mississippi, Missouri, and Illinois rivers in the areas that were hit the worst during both the 1993 floods and the current event in the states of Missouri and Illinois. In addition, many of the levees that failed in 1993 were rebuilt to withstand an event similar to the 1993 flood, and some of the remaining properties on the floodplains were flood-proofed to some degree. As part of the AIR U.S. inland flood model validation of the 1993 event, AIR found the exposure change alone reduced the modeled loss by tens of millions of dollars in both states. Strengthened defenses and flood-proofing will reduce losses to some degree as well.

In the U.S., residential flood insurance is typically offered to homeowners only through the National Flood Insurance Program (NFIP). Established in 1968, the NFIP lets residential property owners purchase flood insurance from the government. An extension of the NFIP has been considered—such that the program would be long-term (currently, it undergoes repeated extensions). The NFIP has been the subject of increasing scrutiny over the years, and it is hoped by some legislators that the current flooding disaster in the U.S. may motivate important changes to this program.

Commercial business can add flood as an endorsement to their property policy, although it is often subject to sublimits. The experience of Hurricane Katrina revealed that commercial insurers did not always have good information about their exposure to flood and indeed estimates of total industrywide insured flood values remain hard to obtain.

Update 1 | Downloads
Posting Date: January 7, 2016, 2:30:00 PM