DES MOINES — With seven days remaining in June, Iowa precipitation totals remain 2 inches below normal with nearly the entire state in some form of dryness or drought, according to the latest Water Summary Update.
As a result of this lack of rainfall, streamflow is down across the state, and concern remains for shallow groundwater availability. Severe drought now covers almost 44 percent of the state, up from only eight percent at the start of June.
"Current and near term projected rainfall should help ease drought conditions, although the U.S. Drought Monitor for this week does not include rain that fell after Tuesday morning,” said Tim Hall, DNR’s coordinator of hydrology resources. “Conditions prior to this new rain show continuing deterioration, but we are anticipating improved conditions next week. The next Water Summary Update on July 10 should show a better situation in Iowa."
Hot and dry conditions blanketed the state for much of the first half of June as the jet stream remained farther north, allowing a stable dome of high pressure to block the normal storm track through the Midwest. As of June 23, the preliminary statewide average precipitation is 1.51 inches, tying 1956 as the eighth driest start to June on record, with seven days remaining. A drier start was last reported in 1992.
This week, a more active storm track returned to the Midwest, bringing much needed rainfall across the state, along with several days of severe hail and high wind reports. Recent temperatures have been more seasonal compared to the first two weeks of June, when multiple days of upper 80s and 90s were reported. The preliminary statewide average temperature through June 23 is 79.6 degrees, 4.6 degrees above normal.
Since the last Water Summary Update, streamflow conditions across approximately a quarter of the state are now classified as “much below normal,” including the Skunk, Des Moines, Raccoon and Little Sioux river basins. Most of the state’s streamflows have now moved into “below normal” conditions.
Soil moisture levels across the state continued to decline in June. One year ago, more than 90 percent of the state had adequate or surplus soil moisture. As of June 21, only about one third of the state had adequate or surplus soil moisture.
The number of Iowa water utilities that have put in place voluntary or mandatory water use restrictions has expanded, but recent cooler and wetter weather has decreased demand. This should help reduce stress on most water systems, and to lower the short-term concern for water availability. A return to hot and dry weather could reverse this change, and Iowans should contact their local water utility with any concerns they may have for their area.
For a thorough review of Iowa’s water resource trends, go to iowadnr.gov/WaterSummaryUpdate.
The report is prepared by technical staff from Iowa DNR, the Iowa Department of Agriculture and Land Stewardship, IIHR—Hydroscience and Engineering, and the U.S. Geological Survey, in collaboration with Iowa Homeland Security and Emergency Management Department.