Sediment Deposition and Selected Water-Quality Characteristics in a Developing Watershed, Northeast, Kansas, USA

Abstract

The Lake Olathe watershed, located in northeast Kansas, USA, was investigated to determine sediment deposition rates, yields, loads, and trends in selected water-quality constituents and diatom community composition in reservoir sediment cores. Industrial and residential land use in the watershed has increased from 1980 to the present. Approximately 417,000 m³ of sediment have been deposited in Cedar Lake, located upstream from Lake Olathe, since dam closure at Cedar Lake in 1938, and 391,000 m³ have been deposited in Lake Olathe since dam closure in 1956. Estimated mean annual phosphorus yield to Cedar Lake was 4.2 (kg/yr)/ha and 1.0 (kg/yr)/ha to Lake Olathe. Trend analysis of phosphorus concentration with depth of sediment showed that phosphorus concentrations in sediment in Lake Olathe have been increasing over time and indicate accelerated lake eutrophication. The herbicides alachlor and metolachlor were detected in sediment in both reservoirs, with larger concentrations corresponding to more recent deposition, suggesting increased use of agricultural herbicides over time. Diatom species in reservoir bottom sediment were identified and used as indicators of reservoir eutrophication. The diatom Cyclotella bodanica, an indicator of low organic-enriched water, and Cyclotella meneghiniana, an indicator of organic-enriched water, both were identified at different depths in the sediment profile from Lake Olathe. The presence of both of these diatoms suggests varying periods of low and high eutrophication in Lake Olathe from 1956 to 2000.

Additional information about the Lake Olathe Nutrient Study in Kansas can be found at: http://ks.water.usgs.gov/studies/qw/olathe/

Mau, D.P., 2002, Sediment deposition and selected water-quality characteristics in a developing watershed, northeast, Kansas, USA [abst.], in Books of Abstracts, 9th International Symposium on the Interactions Between Sediments and Water, Banff, Canada, May 5-10, 2002: International Association for Sediment Water Science, p. 37.

To request a paper copy of this abstract, email: dpmau@usgs.gov