Environ Model Assess (2008) 13:275–289 DOI 10.1007/s10666-007-9090-x Circulation and Stream Plume Modeling in Conesus Lake Yan Li · Anthony Vodacek · Nina Raqueño · Robert Kremens · Alfred J. Garrett · Isidro Bosch · Joseph C. Makarewicz · Theodore W. Lewis Received: 5 January 2006 / Accepted: 4 March 2007 / Published online: 21 April 2007 © Springer Science + Business Media B.V. 2007 Abstract A three-dimensional hydrodynamic model that includes the effect of drag from macrophytes was applied to Conesus Lake to study the seasonal circu- lation and thermal structure during spring and early summer. Local weather conditions and stream flow data were used to drive the model. The drag coeffi- cient for macrophytes was calculated as a function of leaf density. In general, the model results show good agreements with the observations, including vertical temperature profiles measured at two locations and average surface temperature derived from calibrated thermal imagery for large-scale simulations of the en- tire lake. Additional high-resolution simulations were carried out to understand water circulation and trans- port of sediment and model-generated tracer during hydrometeorological events at stream mouths for two experimental sites. The model results show that the Y. Li (B ) · A. Vodacek · N. Raqueño · R. Kremens Digital Imaging and Remote Sensing Laboratory, Center for Imaging Science, Rochester Institute of Technology, Rochester, NY 14623-5604, USA e-mail: yxl4059@cis.rit.edu A. J. Garrett Savannah River National Laboratory, Westinghouse Savannah River Co., Aiken, SC 29802, USA I. Bosch Department of Biology, State University of New York College at Geneseo, Geneseo, NY 14454, USA J. C. Makarewicz · T. W. Lewis Department of Environmental Science and Biology, State University of New York College at Brockport, Brockport, NY 14420, USA plume development at stream mouths during storm events in Conesus Lake are site-dependent and may either be current- or wind-driven. The results also show a significant effect from the presence of macrophytes on sediment deposition near stream mouths. Keywords Hydrodynamic modeling · Lake circulation · Hydrometeorological event · Stream plume · Macrophyte · Conesus Lake · Remote sensing 1 Introduction Conesus Lake is a multipurpose body of water and is used as a source of drinking water for about 15,000 residents inside and outside of the watershed [13]. As of 1999, about half of the land use within the Conesus Lake watershed was agricultural. Runoff from agricul- tural lands containing soil and nutrients causes eutro- phication and a degradation of water quality in the lake [3, 21]. The impacts to water quality include increased macrophyte and metaphyton growth and these are sig- nificant issues for Conesus Lake residents because of impairments to swimming and boating [16]. Studies conducted at the State University of New York (SUNY) at Brockport have demonstrated that nutrient loading during hydrometeorological events in Conesus Lake contributes massive amounts of phos- phorus and nitrate to the lake in short periods of time [15]. One consequence of the excess nutrients is a nar- row but dense band of macrophytes and metaphyton [3] that grows along nearly the entire perimeter of the lake. In some shallow areas, particularly near streams, the macrophytes form expansive beds that cover most