Streamflow alteration can adversely affect the availability and quality of habitat needed by fish and wildlife. Findings show that certain human activities throughout Kansas cause decreased streamflow or declining groundwater levels. Researchers assessed streamflow alteration as it relates to habitat management by analyzing data from 129 USGS streamgages across the state from 1980 through 2015.

“The most likely explanations for altered streamflows are changes in precipitation and human activity,” said Kyle Juracek, a USGS scientist and the lead author of the study. “Since there has not been a pronounced change in annual precipitation in Kansas since 1950, human activity is the likely explanation.”

Agricultural practices have one of the greatest effects on streamflow. Ongoing pumping of groundwater from the High Plains aquifer, mostly for irrigation, has resulted in an ongoing drop in groundwater levels in parts of western Kansas. In some areas, levels have declined 50 to 100 feet or more. Studies have shown there is a connection between groundwater and surface water, meaning that a reduction in groundwater levels can cause streamflow in the affected areas to also decline.

Statewide, agricultural land-management practices implemented to reduce runoff and soil erosion may have been responsible, in part, for decreased duration and magnitude of high flows. Also, the implemented practices may have been partly responsible for increasing low flows at several sites in central and eastern Kansas.

In urban areas, the increase in impervious surfaces, such as roads and sidewalks, has resulted in “flashier” streamflows with more frequent and larger peak flows. Downstream effects of eight large reservoirs in western Kansas typically included decreased peak flows and average monthly flows.

“This assessment greatly improves our understanding of current stream habitat conditions across Kansas and will be helpful in guiding conservation efforts for aquatic species in the state,” said Jordan Hofmeier, aquatic ecologist with the Kansas Department of Wildlife, Parks and Tourism. 

Decreased streamflow is a concern because it may adversely affect the availability and quality of habitat needed by fish and wildlife. For example, in southwest Kansas, declining streamflow likely has adversely affected habitat for the Arkansas darter, a state threatened fish species.

“This study increases the knowledge base and understanding of the changing dynamics of Kansas streams and will allow for predictions into the future concerning the state’s aquatic natural resources,” said Vernon Tabor, a biologist with the U.S. Fish and Wildlife Service.  

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