News Release

U.S. Department of the Interior
U.S. Geological Survey

Median Flow Estimated for Kansas Stream Segments

The U.S. Geological Survey (USGS) today released the results of a study to estimate median flows for streams in Kansas. The Kansas State Legislature, by enacting Kansas Statute KSA 82a-2001 et. seq., mandated the criteria for determining which Kansas stream segments would be subject to classification and water-quality regulation by the State.

The streamflow study, conducted by the USGS in cooperation with the Kansas Department of Health and Environment, estimated the median flow at the downstream end of the 2,232 stream segments on the Kansas Surface Water Register. One criterion established by the statute for the selection as a classified stream segment is based on the statistic of median flow (the flow that is equaled or exceeded at least half of the time) being equal to or greater than 1 cubic foot per second.

As mandated by the statute, streamflow information from the most recent 10 years of record for USGS streamgaging stations within Kansas and in adjacent states was used to make the estimates. Using the streamflow information from the most recent 10 years of record for each gaging station, 30 percent of the 2,232 stream segments on the Kansas Surface Water Register had median flow values of less than 1 cubic foot per second and as designated in the statute would be removed from the Register unless other criteria existed for them to be retained.

The USGS, in its continuing mission to provide hydrologic information for the Nation, conducted an additional analysis of the median flows in Kansas streams using all-available hydrologic information. This analysis differed only in that it considered the entire period of record for each streamgaging station instead of only the most recent 10 years. In this analysis, 40 percent of the 2,232 stream segments on the Kansas Surface Water Register had median flows of less than 1 cubic foot per second. This analysis reflects long-term streamflow records that on the average are dryer than the most recent 10 years.

Results of the USGS study are printed in, "Estimates of median flows for streams on the Kansas Surface Water Register," by Charles A. Perry, David M. Wolock, and Joshua C. Artman. Copies of Water-Resources Investigations Report 02-4292 are available from the USGS Information Services, Box 25286, Federal Center, Denver, CO 80225-0286, or call 1-888-ASK-USGS. A limited number of paper copies are available from the USGS office in Lawrence, Kansas. To view the report and other information about this study online, visit:

For a statewide color map summarizing the study results, visit:

For other water information in Kansas, visit:

The USGS, a bureau within the Department of the Interior, serves the nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.