Stewart Rounds is a Scientist Emeritus at the USGS Oregon Water Science Center.
Dr. Rounds joined the U.S. Geological Survey in 1992 and worked on a wide variety of studies, with a focus on water-quality monitoring and modeling of rivers and lakes around Oregon. In 2020, Stewart retired and continues to volunteer with USGS as a Scientist Emeritus.
Professional Experience
Dr. Rounds' research interests focus on the water-quality modeling of river and lake systems, with particular emphasis on temperature, nutrients, dissolved oxygen, and algae. Ongoing studies focus on producing a better understanding of heat fluxes and heat transport in the Willamette River system. Most of his work focuses on developing a better understanding of the characteristics and water-qualit
Dr. Rounds is the author of the Alkalinity Calculator, a tool that analyzes alkalinity titrations, and the Data Grapher, a set of tools to make custom graphs and tables from USGS continuous water-quality monitoring data.
Education and Certifications
B.S. -- Chemistry, 1985 - University of Illinois at Urbana-Champaign
Ph.D. -- Environmental Science & Engineering, 1992 - Oregon Graduate Institute of Science & Technology
Science and Products
Field techniques for the determination of algal pigment fluorescence in environmental waters—Principles and guidelines for instrument and sensor selection, operation, quality assurance, and data reporting
The use of algal fluorometers by the U.S. Geological Survey (USGS) has become increasingly common. The basic principles of algal fluorescence, instrument calibration, interferences, data quantification, data interpretation, and quality control are given in Hambrook Berkman and Canova (2007). Much of the guidance given for instrument maintenance, data storage, and quality assurance in Wagner and ot
Tracking heat in the Willamette River system, Oregon
The thermal landscape of the Willamette River—Patterns and controls on stream temperature and implications for flow management and cold-water salmonids
Updates to models of streamflow and water temperature for 2011, 2015, and 2016 in rivers of the Willamette River Basin, Oregon
Estimating stream temperature in the Willamette River Basin, northwestern Oregon—A regression-based approach
Integrated tools for identifying optimal flow regimes and evaluating alternative minimum flows for recovering at-risk salmonids in a highly managed system
Modeling water temperature response to dam operations and water management in Green Peter and Foster Lakes and the South Santiam River, Oregon
Chapter A6. Section 6.2. Dissolved oxygen
Temperature and water-quality diversity and the effects of surface-water connection in off-channel features of the Willamette River, Oregon, 2015–16
Effects of harmful algal blooms and associated water-quality on endangered Lost River and shortnose suckers
Evaluation of restoration alternatives using hydraulic models of lake outflow at Wapato Lake National Wildlife Refuge, northwestern Oregon
Evaluation of restoration alternatives using water-budget tools for the Wapato Lake National Wildlife Refuge, northwestern Oregon
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Harmful Algal Blooms and Drinking Water in Oregon
Water Quality in the Willamette River at Portland, Oregon
Willamette River Studies
Water Temperature Modeling in the Middle Fork Willamette and South Santiam River Basins
Henry Hagg Lake Water-Quality Model
Tualatin River Basin Water Quality Assessment
CE-QUAL-W2 models for the Willamette River and major tributaries downstream of U.S. Army Corps of Engineers dams: 2011, 2015, and 2016
USGS Data Grapher
This is a data graphing utility that allows the user to build graphs of data from selected USGS stations. Select the station, the type of graph, the parameter(s) to plot, and the starting and ending dates for the graph.
Alkalinity Calculator
The Alkalinity Calculator will analyze the titration curve and calculate the alkalinity or acid neutralizing capacity (ANC) of the sample using one or more of several different methods. Alkalinity is for filtered samples, while ANC is for unfiltered samples. The results will be displayed in tabular and graphical form.
Science and Products
- Publications
Filter Total Items: 61
Field techniques for the determination of algal pigment fluorescence in environmental waters—Principles and guidelines for instrument and sensor selection, operation, quality assurance, and data reporting
The use of algal fluorometers by the U.S. Geological Survey (USGS) has become increasingly common. The basic principles of algal fluorescence, instrument calibration, interferences, data quantification, data interpretation, and quality control are given in Hambrook Berkman and Canova (2007). Much of the guidance given for instrument maintenance, data storage, and quality assurance in Wagner and ot
Tracking heat in the Willamette River system, Oregon
The Willamette River Basin in northwestern Oregon is home to several cold-water fish species whose habitat has been altered by the Willamette Valley Project, a system of 13 dams and reservoirs operated by the U.S. Army Corps of Engineers. Water-resource managers use a variety of flow- and temperature-management strategies to ameliorate the effects of upstream Willamette Valley Project dams on theThe thermal landscape of the Willamette River—Patterns and controls on stream temperature and implications for flow management and cold-water salmonids
Water temperature is a primary control on the health, diversity, abundance, and distribution of aquatic species, but thermal degradation resulting from anthropogenic influences on rivers is a challenge to threatened species worldwide. In the Willamette River Basin, northwestern Oregon, spring-run Chinook salmon (Oncorhynchus tshawytscha) and winter-run steelhead (O. mykiss) are formerly abundant cUpdates to models of streamflow and water temperature for 2011, 2015, and 2016 in rivers of the Willamette River Basin, Oregon
Mechanistic river models capable of simulating hydrodynamics and stream temperature are valuable tools for investigating thermal conditions and their relation to streamflow in river basins where upstream water storage and management decisions have an important influence on river reaches with threatened fish populations. In the Willamette River Basin in northwestern Oregon, a two-dimensional, hydroEstimating stream temperature in the Willamette River Basin, northwestern Oregon—A regression-based approach
The alteration of thermal regimes, including increased temperatures and shifts in seasonality, is a key challenge to the health and survival of federally protected cold-water salmonids in streams of the Willamette River basin in northwestern Oregon. To better support threatened fish species, the U.S. Army Corps of Engineers (USACE) and other water managers seek to improve the thermal regime in theIntegrated tools for identifying optimal flow regimes and evaluating alternative minimum flows for recovering at-risk salmonids in a highly managed system
Water resource managers are faced with difficult decisions on how to satisfy human water needs while maintaining or restoring riverine ecosystems. Decision sciences have developed approaches and tools that can be used to break down difficult water management decisions into their component parts. An essential aspect of these approaches is the use of quantitative models to evaluate alternative managModeling water temperature response to dam operations and water management in Green Peter and Foster Lakes and the South Santiam River, Oregon
Significant FindingsGreen Peter and Foster Dams have altered natural seasonal temperature patterns in the South and Middle Santiam Rivers of the Willamette River Basin in northwestern Oregon. Cold-water releases from Green Peter Dam, upstream of Foster Lake, contribute to the cool-water conditions at Foster Dam. In summer, unseasonably cold water typically is discharged from Foster Dam into the FoChapter A6. Section 6.2. Dissolved oxygen
Accurate data for the concentration of dissolved oxygen in surface and ground waters are essential for documenting changes in environmental water resources that result from natural phenomena and human activities. Dissolved oxygen is necessary in aquatic systems for the survival and growth of many aquatic organisms and is used as an indicator of the health of surface-water bodies. This section of tTemperature and water-quality diversity and the effects of surface-water connection in off-channel features of the Willamette River, Oregon, 2015–16
Water-quality conditions (including temperature) in the Willamette River and many of its adjacent off-channel features, such as alcoves and side channels, were monitored between river miles 67 (near Salem, Oregon) and 168 (near Eugene, Oregon) during the summers of 2015 and 2016. One or more parameters (water temperature, dissolved oxygen, pH, specific conductance, and [or] water depth) were contiEffects of harmful algal blooms and associated water-quality on endangered Lost River and shortnose suckers
Anthropogenic eutrophication contributes to harmful blooms of cyanobacteria in freshwater ecosystems worldwide. In Upper Klamath Lake, Oregon, massive blooms of Aphanizomenon flos-aquae and smaller blooms of other cyanobacteria are associated with cyanotoxins, hypoxia, high pH, high concentrations of ammonia, and potentially hypercapnia. Recovery of the endangered Lost River sucker Deltistes luxatEvaluation of restoration alternatives using hydraulic models of lake outflow at Wapato Lake National Wildlife Refuge, northwestern Oregon
Wapato Lake National Wildlife Refuge near the city of Gaston in northwestern Oregon was established in 2013, and planning is underway to restore a more natural lake and wetland system after more than 100 years of agricultural activity on the lakebed. Several water-management and restoration alternatives are under consideration, one of which involves opening and reconnecting Wapato Lake’s outlet toEvaluation of restoration alternatives using water-budget tools for the Wapato Lake National Wildlife Refuge, northwestern Oregon
The lakebed in Wapato Lake National Wildlife Refuge (NWR) in northwestern Oregon was farmed for decades prior to the establishment of the refuge in 2013. Planning for restoration of these lands required extensive data collection and construction of a water budget and tools to design and evaluate potential restoration strategies. The U.S. Geological Survey (USGS) and U.S. Fish and Wildlife ServiceNon-USGS Publications**
Rounds, S.A. and Pankow, J.F., 1993, Determination of selected chlorinated benzenes in water by purging directly to a capillary column with whole column cryotrapping and electron capture detection: J. Chromatogr., v. 629, p. 321-327. https://doi.org/10.1016/0021-9673(93)87046-ORounds, S.A., Tiffany, B.A., and Pankow, J.F., 1993, Description of gas/particle sorption kinetics with an intraparticle diffusion model: desorption experiments: Environ. Sci. Technol., v. 27, p. 366-377. https://doi.org/10.1021/es00039a018Rounds, S.A. and Pankow, J.F., 1990, Application of a radial diffusion model to describe gas/particle sorption kinetics: Environ. Sci. Technol., v. 24, p. 1378-1386. https://doi.org/10.1021/es00079a012Bonn, B.A. and Rounds, S.A., 1990, DREAM - Analytical Groundwater Flow Programs: Chelsea, MI, Lewis Publishers, 109 p. https://www.taylorfrancis.com/books/mono/10.1201/9781003069898/dream-bernadine-bonn-stewart-roundsLarson, R.A., and Rounds, S.A., 1987, Photochemistry in Aqueous Surface Layers: 1-Naphthol: chap. 15, pp 206-214 in Photochemistry of Environmental Aquatic Systems, Zika, R.G. and Cooper, W.J., editors, ACS Symposium Series volume 327, American Chemical Society. https://pubs.acs.org/doi/pdf/10.1021/bk-1987-0327.ch015**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- Science
Harmful Algal Blooms and Drinking Water in Oregon
Harmful algal blooms are a major environmental problem in all 50 states.Water Quality in the Willamette River at Portland, Oregon
The U.S. Geological Survey (USGS) has been monitoring water quality in the Willamette River for many years. The USGS National Water-Quality Assessment Program (NAWQA) collects water samples from the Willamette River at Portland, as well as from select sites upstream, as part of a continuing effort to assess the quality of the Nation's waters. The USGS Oregon Water Science Center has multiple...Willamette River Studies
Welcome to the Willamette River Study page. Here you will find links to USGS research for the Willamette River and the Willamette River Basin.Water Temperature Modeling in the Middle Fork Willamette and South Santiam River Basins
Hills Creek, Lookout Point, and Dexter Dams are located on the Middle Fork Willamette River upstream of Eugene in western Oregon, and are important resources managed by the U.S. Army Corps of Engineers (USACE) for flood control, hydroelectric power, recreation, navigation, and irrigation. On the South Santiam River east of Albany in western Oregon, Green Peter and Foster Dams provide functions and...Henry Hagg Lake Water-Quality Model
Henry Hagg Lake is a reservoir located in the foothills of the eastern slope of the Coast Range Mountains of northwestern Oregon. The lake is used for recreation in the summer and flood control in the winter.Tualatin River Basin Water Quality Assessment
In 1990, the USGS began assessing water-quality in the Tualatin River. Almost 30 years later, we are still monitoring conditions in the basin. - Data
CE-QUAL-W2 models for the Willamette River and major tributaries downstream of U.S. Army Corps of Engineers dams: 2011, 2015, and 2016
In the Willamette River Basin in northwestern Oregon, stream temperature has been altered by 13 dams operated by the U.S. Army Corps of Engineers (USACE), negatively influencing threatened populations of native salmonids. CE-QUAL-W2, a two-dimensional, hydrodynamic water quality model, has been used to investigate temperature and heat patterns in the Willamette River and the downstream effects of - Multimedia
- Web Tools
USGS Data Grapher
This is a data graphing utility that allows the user to build graphs of data from selected USGS stations. Select the station, the type of graph, the parameter(s) to plot, and the starting and ending dates for the graph.
Alkalinity Calculator
The Alkalinity Calculator will analyze the titration curve and calculate the alkalinity or acid neutralizing capacity (ANC) of the sample using one or more of several different methods. Alkalinity is for filtered samples, while ANC is for unfiltered samples. The results will be displayed in tabular and graphical form.