By B.E. Pickup, W.J. Andrews, B.E. Haggard, and W. Reed Green
Water-Resources Investigations Report 03-4168
Prepared in cooperation with the
Oklahoma Scenic Rivers Commission Oklahoma Water Resources Board
The report is available in PDF format.
The Illinois River and tributaries, Flint Creek and the Baron Fork, are designated scenic rivers in Oklahoma. Recent phosphorus increases in streams in the basin have resulted in the growth of excess algae, which have limited the aesthetic benefits of water bodies in the basin, especially the Illinois River and Lake Tenkiller. The Oklahoma Water Resources Board has established a standard for total phosphorus not to exceed the 30- day geometric mean concentration of 0.037 milligram per liter in Oklahoma Scenic Rivers. Data from water-quality samples from 1997 to 2001 were used to summarize phosphorus concentrations and estimate phosphorus loads, yields, and flowweighted concentrations in the Illinois River basin.
Phosphorus concentrations in the Illinois River basin generally were significantly greater in runoff-event samples than in base-flow samples. Phosphorus concentrations generally decreased with increasing base flow, from dilution, and increased with runoff, possibly because of phosphorus resuspension, stream bank erosion, and the addition of phosphorus from nonpoint sources.
Estimated mean annual phosphorus loads were greater at the Illinois River stations than at Flint Creek and the Baron Fork. Loads appeared to generally increase with time during 1997-2001 at all stations, but this increase might be partly attributable to the beginning of runoff-event sampling in the basin in July 1999. Base-flow loads at stations on the Illinois River were about 10 times greater than those on the Baron Fork and 5 times greater than those on Flint Creek. Runoff components of the annual total phosphorus load ranged from 58.7 to 96.8 percent from 1997-2001. Base-flow and runoff loads were generally greatest in spring (March through May) or summer (June through August), and were least in fall (September through November).
Total yields of phosphorus ranged from 107 to 797 pounds per year per square mile. Greatest yields were at Flint Creek near Kansas (365 to 797 pounds per year per square mile) and the least yields were at Baron Fork at Eldon (107 to 440 pounds per year per square mile).
Estimated mean flow-weighted concentrations were more than 10 times greater than the median and were consistently greater than the 75th percentile of flow-weighted phosphorus concentrations in samples collected at relatively undeveloped basins of the United States (0.022 milligram per liter and 0.037 milligram per liter, respectively). In addition, flow-weighted phosphorus concentrations in 1999-2001 at all Illinois River stations and at Flint Creek near Kansas were equal to or greater than the 75th percentile of all National Water-Quality Assessment program stations in the United States (0.29 milligram per liter).
The annual average phosphorus load entering Lake Tenkiller was about 577,000 pounds per year, and more than 86 percent of the load was transported to the lake by runoff.
Purpose and Scope
Study area description
Streamflow in the Illinois River basin
Phosphorus concentrations, loads, and yields in the Illinois River basin
Estimated annual loads
Estimated seasonal loads
Estimated mean flow-weighted concentrations
Estimated phosphorus loads into Lake Tenkiller
1a. Instantaneous streamflows and total phosphorus concentrations for Illinois River near Watts, Oklahoma, from 1997-2001
1b. Instantaneous streamflows and total phosphorus concentrations for Flint Creek near Kansas, Oklahoma, from 1997-2001
1c. Instantaneous streamflows and total phosphorus concentrations for Illinois River at Chewey, Oklahoma, from 1997-2001
1d. Instantaneous streamflows and total phosphorus concentrations for Illinois River near Tahlequah, Oklahoma, from 1997-2001
1e. Instantaneous streamflows and total phosphorus concentrations for Baron Fork at Eldon, Oklahoma, from 1997-2001
2. Residuals plots of In(instantaneous load) – In(predicted load) in relation to In(instananeous load) for stations in the Illinois River basin, periods 1997-1999, 1998-2000, and 1999-2001
For additional information write to:
U.S. Geological Survey
202 NW 66 St., Bldg. 7
Oklahoma City, OK 73116
Copies of this report can be purchased from:
U.S. Geological Survey
Denver, CO 80225
Download the PDF version of the report for high-resolution, printable pages (3.0MB).
Document Accessibility: Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools convert Adobe PDF documents into HTML or ASCII text, which then can be read by a number of common screen-reading programs that synthesize text as audible speech. In addition, an accessible version of Acrobat Reader 5.0 for Windows (English only), which contains support for screen readers, is available. These tools and the accessible reader may be obtained free from Adobe at Adobe Access.