Oct. 1 through Sept. 30 is known as the “water year,” as snow accumulation after Oct. 1 serves as the primary source of runoff to streams during the following calendar year in many parts of the country. The 2017 Water Year (ending Sept. 30, 2017) brought a statewide precipitation average of 31.99 inches, or 3.28 inches less than normal, while temperatures averaged 50.7 degrees, or 2.6 degrees above normal. This places 2017 as the fourth warmest water year among 144 years of records, and roughly in the middle of the list for precipitation.
While August started out very dry, the last week has seen conditions turning wetter in many of areas in need of rain. Through the first three weeks of August, rain totals were as high as 9.51 inches at Guthrie Center, with totals of 6 inches or more widespread over much of northwest, west central and southwest Iowa.
Stream flows and shallow groundwater conditions have also improved.
For a thorough review of Iowa’s water resource trends, go to www.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.
