DES MOINES - For the second month in a row Iowa has had above normal precipitation, but the water levels in streams remain very low, along with shallow groundwater levels across most of Iowa that are at or near seasonal and historic lows. Palo Alto, Osceola, Sioux and Crawford counties are especially hard hit by low levels of shallow groundwater, according to information compiled by the technical staff from the Iowa Department of Natural Resources, the Iowa Department of Agriculture and Land Stewardship, and the United States Geological Survey, in collaboration with the Iowa Department of Homeland Security and Emergency Management Division.
While it may seem ironic in a time of low water levels, official note that "concrete frost" currently exists across northern Iowa, especially north of U.S. Highway 20. The phenomenon was created when rainfall in December and January resulted in the top layer of ground becoming saturated and then freezing nearly solid. Until the ground thaws in that region, more runoff than normal will occur from snowmelt or rainfall. River flooding or even flash flooding could result, DNR officials warn.
But, on the opposite side of the coin, fish kills that were predicted this winter in natural lakes and farm ponds due to low water conditions and lack of drainage tile flow did not happen. In those regards, conditions are better than expected.
Lake levels for the most part are lower in the region, according to DNR officials, but in times of drought conditions, most lakes respond well through the impact lower water levels have on vegetation.
"When we look at historical records, all the way back into the 1930s, we are not anywhere close to the extreme lows," noted Mike Hawkins, a Fisheries Biologist for the Iowa DNR as Spirit Lake. "For the region, we are probably sitting pretty well. With aquatic plant life, there is an upside to droughts, they respond very well to it. There is a good amount of rejuvenation during lake droughts. Any time there is a positive impact to vegetation, it improves water quality and the fisheries."
According to Hawkins, one of the biggest factors to affect lakes this winter has been the absence of prolonged snow cover on the ice, which allows sunlight to penetrate the ice and increase oxygen levels for a majority of the winter.
Officials admit it will take a significant amount of precipitation in the Spring to bring area lake and water levels back to normal. To do so may take more than one Spring season.