Iowa communities along the Mississippi River will most likely see major flooding this spring.
A National Weather Service flood outlook released last week shows an over 50% chance of extensive inundation all along the state’s eastern boundary. Probability of moderate flooding is at 95% in most areas. Western Iowa faces lower, but still significant risk.
Heavy precipitation in 2019, still-saturated soils and heavy snowpack to the north contribute to the elevated flood risk.
Radio Iowa reported that Gov. Kim Reynolds said official are coordinating with local emergency management teams. Reynolds said the Army Corps of Engineers is releasing water already to make room for melted snow to the north.
Last summer’s Mississippi River flooding was the longest in recorded history, lasting nearly 200 days. A coalition of river city mayors estimated damage to be over $2 billion along the length of the river.
The Quad Cities have been preparing since the National Weather Service reported earlier this year a 95 percent chance of pronounced flooding in the area through May. As of Tuesday, their temporary barriers had been in place for 48 days. This week, their preparations proved insufficient.
Tuesday afternoon, Mississippi River floodwaters suddenly rushed into Davenport when HESCO Barriers — military grade defense boxes used to make temporary walls — succumbed to the force of the water. Officials saw early signs, the Quad City Times and Dispatch-Argus reported, and began urging people in some areas to evacuate when the temporary levees began breaking around 3:30 pm. The HESCO barriers had never been tested in waters above 21.5 feet, but as of 4:30 pm the Mississippi was at 21.87 feet, heading quickly to the expected 22.4 foot crest.
Not everyone received or took seriously the evacuation warnings, and many had to be rescued by boat after the fact. Once the water came rushing in, there was little time to take action. No serious injuries were reported.
The Weather Channel reported that floodwater began to recede Wednesday morning, and that at their peak levels surpassed 6 feet in some areas. A new expected crest of 22.7 feet is expected later today, which could surpass the 22.6 foot record set in 1993.
Scott County officials and Gov. Kim Reynolds are hoping President Trump’s earlier disaster declaration for western Iowa will extend into the Quad Cities area, local media reported.
An electric barrier between Dickinson County’s Milford Creek and the Iowa Great Lakes proved its worth this summer, protecting the lakes from invasive fish during the region’s second highest flood on record.
Invasive carp species were first found in the Great Lakes in 2011. Flooding accelerates their entry via streams by allowing them to swim upstream and over dams. Such species can disrupt food chains, ecological processes and even recreation (see invasive Asian carp body slamming boaters here).
The Iowa Department of Natural Resources installed the $1 million barrier in 2012. During floods, it ramps up its electric field to prevent fish from passing through. Floods in late June and early July were the highest since 1933.
Scientists have since found invasive fish in Milford Creek but say the barrier seems to have fenced in most, if not all of them. DNR fisheries biologist Mike Hawkins told Iowa Public Radio that if any individuals made it in, they should not be able to reproduce in the lake.
A recent study by NASA, the first of its kind, found that significant amounts of water are shifting around Earth’s surface.
Scientists used data from the Gravity Recovery and Climate Experiment (GRACE), two satellites, to track gravitational changes made by hydrologic shifts in 34 regions around the world. From 2002 through 2016, they paired this information with satellite precipitation data, NASA/U.S. Geological Survey Landsat imagery, irrigation maps, and public reports of human activities related to agriculture, mining and reservoir operations.
In short, researchers found that wetter areas are getting wetter and drier areas are getting drier. Jay Famiglietti of NASA’s Jet Propulsion Laboratory is one of the study’s authors. He explains, “We see a distinctive pattern of the wet land areas of the world getting wetter – those are the high latitudes and the tropics – and the dry areas in between getting dryer. Embedded within the dry areas we see multiple hotspots resulting from groundwater depletion.”
Scientists point to a couple of things to explain freshwater depletion in areas that are getting drier. In Saudi Arabia and many other parts of the world, for example, ground water has been depleted for agricultural purposes. The study also found that groundwater availability changes with periods of drought. From 2007 through 2015, southwestern California lost enough freshwater to fill 400,000 Olympic size swimming pools because the region saw less precipitation and snowpack during that time and had to rely on groundwater more heavily.
Freshwater loss in many regions was attributed to global warming that caused glaciers and ice sheets to melt away. However, Famiglietti said that much more research is needed to determine whether climate change caused the other hydrologic shifts.
GRACE Follow-On, GRACE’s successor, will continue to monitor the movement on water on Earth and is set to launch on May 22nd from Vandenberg Air Force Base California.
Flooding has cost Iowa communities more than $18 billion in the last thirty years, and as the Mississippi and Cedar Rivers continue to swell this spring, Iowans may wonder how much they can expect to pay out on flood disasters in the future.
In recent years, scholars at the Iowa Flood Center have been working to predict just that. HAZUS, developed by the the Federal Emergency Management Agency, provides predictions of the economic impact various magnitudes and types of natural disasters might have across the United States. During 2017, Research Engineer and Assistant Professor Ibrahim Demir and graduate research assistant Enes Yildirim, combined HAZUS’ information on demographics, buildings and structural content with data from the Iowa Flood Information System (IFIS).
As a result, IFIS now offers flood loss and economic damage estimations for twelve communities in the state. These include Cedar Rapids, Cedar Falls, Des Moines, Fort Dodge, Iowa City, Independence, Kalona, Monticello, Ottumwa, Rock Rapids, Rock Valley, and Waterloo. HAZUS’ model makes it possible for users to not only view the overall economic damages to a community but also how much in damages individual buildings can be expected to accrue.
Iowa Flood Center researchers are working to expand this predictive model to other parts of the state. For now, users can use the following guide to learn more about the financial consequences of flooding in any of the aforementioned communities.
Ken Parks is the Missoula County Disaster and Emergency Services deputy coordinator. He said to the Associated Press, “If you live anywhere near a stream or waterway in western Montana you need to be prepared to leave your home. This is going to come earlier than we expected. We’re trying to get out ahead of this thing and get the message out that this could be a very dangerous situation.”
The report aggregated data from climate deregulation policy trackers from the environmental law programs at Harvard University and Columbia University to come up with a total of 67 environmental regulations that the administration has sought to rollback. Reporters split the policies into three categories: those that have already been overturned, those that are on their way to being overturned and those whose fate is unclear due of court actions. The largest category of 33 rules are those that have already been reversed.
There are a few among them that are most relevant for Iowans. First, the administration has reversed an Obama-era regulation that required federal buildings and infrastructure projects to be constructed in accordance with higher flood protection standards. Under this rule, new projects in flood plains would have had to be either elevated or flood proofed at a minimum of two feet above the 100-year floodplain. Recent research from the University of Iowa’s Flood Center found that as the climate continues to warm, the risk of flooding in Iowa and the northern U.S. is increasing.
The administration has also opted to reject the Environmental Projection Agency’s research on a particular pesticide and allow for its further use. Following the EPA’s study of the pesticide chlorpyrifos, which found to pose a risk for fetal brain and nervous system development, the Obama administration proposed a ban of the pesticide. Trump-appointed EPA administrator Scott Pruitt argued that further study of the chemical is needed prior to a ban.
The list of environmental policies reversed by the administration goes on, and just three have been successfully reinstated after environmental groups sued the Trump administration.
Jonathan Godt of the U.S. Geological Survey told the New York Times, “It was pretty rare, in essence a worse-case scenario from that standpoint. The same rainfall that falls on a burned landscape can cause a lot more damage than it would before a fire.”
AccuWeather officials have predicted that a shift in the jet stream will bring more moisture from the Pacific Ocean into southern California’s atmosphere by January 23rd and 24th. They caution that the weather pattern presents the risk for “locally heavy rainfall, flash flooding and a significant risk of mudslides.” Their report states that areas surrounding Point Conception, California are most likely to be affected.
February and March are heavy precipitation months for Santa Barbara county, and following California’s record-setting year for wildfires, conditions are right for faster-moving and more destructive landslides.
AccuWeather meteorologist Evan Duffey said, “People need to leave the area by evacuation deadlines as they are given. Once a mudslide begins, there may only be minutes to seconds before a neighborhood is wiped out.”
The 2017 Water Year came to an end recently according to a report from the Iowa Department of Natural Resources (DNR).
The “water year” runs from September 30th through October 1st. Overall, the 2017 water year has been drier and a bit warmer than usual. The statewide precipitation average was about 32 inches, which is roughly 3.28 inches less than usual. Precipitation was around average during the winter months, but fell below normal during the summertime.
Temperatures in the state averaged 50.7 degrees Fahrenheit, which made 2017 the fourth warmest year on the Iowa DNR’s 144 year record. While temperatures were mostly typical during the growing season, they were higher than usual for most of the winter months. This year brought the second warmest November and the third warmest February on record.
This week’s On The Radio segment discusses how climate change is making storms like Harvey more likely.
Transcript: Over 51 inches of rain fell in the Houston area last month during Hurricane Harvey, setting a record for the continental U.S., and scientists say a changing climate added to the deluge.
This is the Iowa Environmental Focus.
The Clausius-Clapeyron equation, a law of thermodynamics, says that the warmer a body of air is, the more moisture it can hold. Sea surface temperatures near where Harvey picked up its strength were about 1 degree Celsius higher than average, making the air above it warmer too. In this case, the atmosphere surrounding Hurricane Harvey was able to hold roughly three to five percent more moisture than usual.
In addition, sea levels have risen by about six inches in the last few decades due to global warming. Even minimal sea level rise can lead to a large increase in damages to structures on land during a flood.
While climate change did not cause Hurricane Harvey directly, scientists say it will likely make category four storms like it more frequent in the future.