Water Summary Update: Some rain in June, but drought spreads

The month of June saw 3.31 inches of rain in Iowa, almost two inches less than normal. The lower than normal rainfall, combined with warmer than normal temperatures, resulted in an expansion of drought conditions across the state.

Severe drought now covers nearly 38 percent of the state, up from less than 8 percent at the beginning of June. Since the first of June, severe drought conditions have expanded from 12 counties in northwest Iowa across nearly all of northern Iowa, and as far south as Dallas County. Severe drought conditions now cover all or parts of 45 counties. The last time that the overall statewide drought conditions were worse than this week was in early September 2020.

This dryness is reflected in decreasing streamflows in central and northwestern Iowa, and continued concern for shallow groundwater supplies in some areas of the state.

"The hope was for normal rain in June, but we ended up almost two inches short for the month. Some rain was good, but more is needed to reverse the trend toward drier conditions in the state,” said Tim Hall, DNR’s coordinator of hydrology resources. “Unfortunately, we are entering the time of the year when water demand goes up, so more rainfall is needed in the weeks ahead."

Since the last water summary update, streamflow conditions across approximately half of the state remain in the below normal condition.

Soil moisture levels across the state have continued to decline. One year ago, 16 percent of subsoil moisture in Iowa was rated as short or very short. As of July 6, that number is now 63 percent. 

In the Missouri River basin, the U.S. Army Corps of Engineers has enacted water conservation measures for the second half of the navigation season, which began on July 1. Very dry conditions continue to impact the upper Missouri River Basin above Sioux City. The forecasted runoff for 2021 could be the tenth lowest runoff in the upper basin since 1898.