Rainfall in the last part of August helped to lift many parts of Iowa out of drought conditions, but some parts of the state are still experiencing extreme drought, according to the latest Water Summary Update.
The Water Summary Update is a succinct monthly report of Iowa’s water resources and those events that affect them prepared by the technical staff at Iowa DNR, the Iowa Department of Agriculture and Land Stewardship, IIHR—Hydroscience and Engineering, and the U.S. Geological Survey, in partnership with Iowa Homeland Security and Emergency Management Department.
The latest summary revealed that while August started off very dry, high rain totals increased groundwater levels and streamflow in many parts of the state. The total area of the state classified as experiencing drought or dryness decreased from over 70 percent at the beginning of the month to 55 percent this week. In contrast, south central Iowa is still experiencing D2 and D3 drought conditions. Clarke county and Wapello county are seeing the most extreme dryness.
Researchers point out that August temperatures this year have been about three to four degrees cooler than normal, on average. Lower temperatures slow down evaporation rates and provide a protective factor for crops in drought-stricken areas.
To follow Iowa DNR’s regular water summary update, visit their website here.
A recent study by the Pew Charitable Trusts generated flood risk scores for 84,123 primary and secondary schools nationwide.
The report’s authors pointed out that flooding is the most costly and common natural disaster, affecting every region of the U.S. Many times, severe floods badly damage schools, causing them to close. For example, the study points out, floods in West Virginia in June 2016 cost $130 million in damage to regional schools.
Researchers used three metrics to generate county-wide composite flood risk vulnerability scores for schools in all fifty states including: a school’s location within a designated flood zone, the percentage of a school’s neighborhood (as represented by ZIP code) located within a flood zone, and the number of historical flood-related federal disaster declarations in that county.
Among the study’s major findings are that flood risk is distributed across diverse regions of the country. Schools with the highest flood risk scores were located in the Atlantic Coast, Gulf Coast, Mississippi River corridor, and southwestern Arizona. Similarly, those schools with the highest composite flood risk scores were located in both coastal and inland regions. Those 100 counties with the highest composite flood risk scores include 6,444 schools that serve almost 4 million students.
The study made some recommendations for steps policymakers can take to increase flood resiliency for schools. They included generating up-to-date local flood maps, developing pre-disaster flood plans for schools, working to leverage federal assistance, and relocating schools out of floodplains if possible.
The Pew Charitable Trusts full analysis can be found here.
Researchers at the University of Illinois recently released a study that predicts the impact climate change will have on agriculture in the state.
The research article, published in PLOS One, centers around one variable called “field working days.” This term refers to the days during which the weather is suitable for farmers to plant, till, monitor, or harvest crops. Adam Davis is a University of Illinois USDA Agricultural Research Service ecologist. Davis said, “Everything else flows from field working days. If you’re not able to work, everything else gets backed up. Workable days will determine the cultivars, the cropping system, and the types of pest management practices you can use. We’re simply asking, ‘Can you get in to plant your crop?”
Utilizing previously developed climate models, the researchers predicted the number of field working days for farmers in Illinois from 2046 to 2065 and from 2080 to 2099. The study modeled three possible trajectories ranging from mild to severe climate change.
Notably, the study predicts that the usual planting window for corn, April and May, will be too wet for planting in the future. Too much rain can be harmful for seedlings because it can wash them away or lead to harmful fungal and bacterial growth.
Davis said, “The season fragments and we start to see an early-early season, so that March starts looking like a good target for planting in the future. In the past, March has been the bleeding edge; nobody in their right mind would have planted then. But we’ve already seen the trend for early planting. It’s going to keep trending in that direction for summer annuals.”
While the spring months grow wetter, summer months are predicted to become drier and hotter, especially in the southern parts of Illinois. “Drought periods will intensify in mid- to late-summer under all the climate scenarios. If farmers decide to plant later to avoid the wet period in April and May, they’re going to run into drought that will hit yield during the anthesis-silking interval, leading to a lot of kernel abortion,” Davis explained.
The article offers two possible adaptations for farmers. They could opt for earlier planting of long-season varieties that should have enough time to pollinate before summer droughts, but they’d risk getting hit by a late winter storm. Or, the researchers suggest, farmers could plant short-season cultivars that are harvested prior to summer droughts. In this case, growers could be sacrificing yield due to the shorter growing season.
Either way, Davis said, farmers should begin considering how they can best adapt to the changing climate. He said, “Now is the time to prepare, because the future is here.”
The Iowa Department of Natural Resources (DNR) recently released its latest Water Summary Update. Each update provides an overview of the status of Iowa’s water resources using four categories: precipitation, streamflow, drought, and shallow groundwater. The latest update provides a water resource snapshot of trends from October 10 through November 3.
As Iowa heads into the driest season of the year, stretching from November through February, October was recorded as the first month since June in which rainfall fell below normal levels. “Abnormally dry,” or drought conditions persisted for south-central Iowa, with the lowest reported October rainfall of 0.54 inches recorded in Story County. Areas of north central and northeastern Iowa, which had experienced heavy rainfall throughout much of September, saw drier conditions at last.
Temperatures throughout the month of October were warmer than they have been since 2007, averaging about 4.5 degrees above normal. This season’s first freeze is yet to occur for the Des Moines metro area, as well as far eastern and southeastern Iowa. The northwest two-thirds portion of the state experienced its first deep freeze on October 13.
Since the previous Water Summary Update, streamflow in the Chartion River Basin in south central Iowa has decreased to normal levels. However, streamflow for most of Iowa remains above average. More specifically, streamflow in the Cedar, Des Moines, and Upper Iowa River basins remain far above average. The forthcoming four months not only mark the driest season of the year, but also the most hydrologically stable. During this period of time Iowa usually receives about 15 percent of the year’s total rainfall, or 5.5 inches of precipitation. In contrast, summer months in the state bring more than 18 inches of precipitation on average.
Water Summary Updates are released every two weeks or as water resource conditions in Iowa significantly change. They are prepared by the Iowa DNR in partnership with Iowa Department of Agriculture and Land Stewardship, the U.S. Geological Survey, and The Iowa Homeland Security and Emergency Management Division. A complete record of Iowa Water Summary Updates can be found here.
This week’s On The Radio segment discusses Iowa’s 2016 Water Summary Update, released by the Iowa DNR in October.
Transcript: Iowa’s 2016 Water Year, which ended on September thirtieth, is the third wettest year on record in 144 years.
This is the Iowa Environmental Focus.
The Iowa Department of Natural Resources recently released its most recent Water Summary Update. The report provides an overview of the status of Iowa’s water resources and significant events that affect water supplies using four categories: precipitation, stream flow, shallow groundwater, and drought monitoring.
The most recent update is a snapshot of the state’s water resources from August 31 through October 10. The update reveals that average statewide rainfall was 6.29 inches or 2.91 inches above average, making it the rainiest September since 1986.
“The 2016 water year, which began in October 2015, and continued through September of this year, surprised Iowans with major unseasonal events including flooding on Thanksgiving last year, rainfall in January, and major flooding in September. While perhaps unexpected, these are consistent with early predictions from climate scientists that global warming will be characterized by increased variability of weather patterns. For Iowans, this implies that we have to be vigilant and prepare year round. Always stay tuned to the current weather conditions and forecasts.”
Streamflow was also found to be above average throughout the state. Following heavy rain events at the end of September in the Cedar and Wapsipinicon River basins, peak streamflow in several locations was found to be the second-highest in recorded history. These values were only topped by the historic 2008 flood.
For more information about weather and climate in Iowa, visit iowaenvironmentalfocus.org.
From the UI Center for Global and Regional Environmental Research, I’m Jenna Ladd.
Flood mitigation efforts in the state thus far have centered around building levees, flood walls, and protecting utilities, but Iowa researchers have found that upstream structures like wetlands and detention pounds are an effective means of flood prevention. Sen. Rob Hogg of Cedar Rapids said that some lawmakers have acknowledged the need to ramp up these strategies, but the conversation is often buried by health care and education budget arguments. Hogg said, “If you can’t reach agreement over funding the basics, it’s really hard to get to the next level, to discuss funding water management.”
The increasing frequency of extreme rainfall may demand that flood mitigation take center stage at the capital. “We were hard-pressed to get 4-inch rainfalls 100 years ago, and now it’s very common,” said Jerry Schnoor, co-director at the University of Iowa’s Center for Global and Regional Environmental Research. Eugene Takle, director of the climate science program at Iowa State University, agreed, “In the Cedar River basin, we found the 100-year flood a century ago is now very likely to be a 25-year flood.” The Cedar basin’s record flood in 2008 had a $5 billion price tag.
Takle and other experts say these changes are primarily due to climate change. Rising greenhouse gases in the atmosphere allow it to hold more water vapor. “When you have more water vapor, you can expect more rain events,” he said. Takle’s data support this claim: atmospheric water vapor has increased by 31 percent in the winter months since 1970 and by 14 percent in the spring; average annual rainfall in Iowa has risen by 33 percent since 1970. Takle said, “This is consistent with what the climate models said would happen. The Midwest has experienced a big increase in extreme events.” According to NOAA National Centers for Environmental Information, Iowa has had 26 flood disasters with damages adding up to more than $1 billion since 1980.
Larry Weber, director at the University of IIHR – Hydroscience & Engineering, parent organization of the Iowa Flood Center, said that the loss of prairie potholes and wetlands, which can soak up heavy rainfalls, has contributed to these flooding events. He said, “We’ve taken away a lot of those natural storage areas.”
Iowa lawmakers passed a sales-tax funding plan in 2012 to provide $1.4 billion in flood prevention structures, but more funding is needed. Eight-nine towns and cities have identified $35 million in flood prevention structures that do not have funding. Some Iowa lawmakers are working to increase the sales tax by three-eighths of 1 cent in order to fund the Natural Resources and Outdoor Recreation Trust Fund, which would provide $180 million each year to restore wetlands, protect wildlife habitat, reduce runoff and improve trails, and more.
One and a half million dollars in federal supplemental aid money allocated to the Iowa Flood Center’s Iowa Watersheds Project after the 2008 flood has reduced flooding downstream by 15-20 percent in the Otter, Beaver and South Chequest watersheds. The center received $98 million in federal grant money this year for similar flood mitigation projects in 25 additional watersheds. Weber said, “We’re making great strides in the places where we work, we just need to be working in more places — whether it’s through our projects, or the work of other state and federal agencies, private landowners, and nonprofit groups.”
Iowa Department of Natural Resources (DNR) released its most current Water Summary Update earlier this week.
DNR prepares the bi-weekly updates in collaboration with the Iowa Department of Agriculture and Land Stewardship, the U.S. Geological Survey, and The Iowa Homeland Security and Emergency Management Division. Each report provides an overview of the status of Iowa’s water resources and significant events that affect water supplies using four categories: precipitation, stream flow, shallow groundwater, and drought monitoring.
The most recent update is a snapshot of the state’s water resources from August 31st through October 10th. The report notes that different parts of Iowa experienced a wide range of rainfall totals. Heavy rains pelted the Cedar River watershed during much of September, with the largest storm-total rainfall of 10.56 inches near Nora Springs in Floyd County. In contrast, some parts of southeastern Iowa experienced a particularly dry September. Most notably, rain totals were less than one-third of the average near Fairfield and Ottumwa. Average statewide rainfall was 6.29 inches or 2.91 inches above average, making it the rainiest September since 1986.
Streamflow was also reported to be above average for much of the state. The update notes that U.S. Geological Survey employees have been taking additional streamflow measurements following heavy rain events at the end of September in the Cedar and Wapsipinicon River basins. In several locations along the Shell Rock, Cedar, and Wapsipinicon Rivers, peak stream flow was found to be the second-highest in recorded history. These values are only topped by the historic 2008 flood.
October 1st through September 30th is considered the “water year” by experts in the field. The 2016 Water Year, which ended on September 30th, 2016, is the third wettest year on record in 144 years.