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• 1. [Article] Modeling Density Currents in Circular Clarifiers

  Design of sedimentation tanks for solid-liquid separation is often dependent on assuming ideal flow conditions. But the geometry of the tank and density currents as a result of temperature and suspended ...

  Citation × Citation Citation Abstract Copy Title: Modeling Density Currents in Circular Clarifiers Author: Wells, Scott A., LaLiberte, David M. Year: 1998 Design of sedimentation tanks for solid-liquid separation is often dependent on assuming ideal flow conditions. But the geometry of the tank and density currents as a result of temperature and suspended solids influences the fluid mechanics of the tank and can result in significant deviations from ideal flow. A two-dimensional radial flow model was proposed which incorporated the effect of density currents resulting from temperature and suspended solids differentials within the tank. The numerical model predicted the steady-state, layer-averaged radial flow and layer depth. The model solution and field data showed that the momentum and suspended solids of the inflow caused a density current that moved along the clarifier bottom. In the winter, this density current rose as a result of warm inflow water after the initial momentum had decreased and the suspended solids had settled. Title: Modeling Density Currents in Circular Clarifiers Author: Wells, Scott A., LaLiberte, David M. Year: 1998 Design of sedimentation tanks for solid-liquid separation is often dependent on assuming ideal flow conditions. But the geometry of the tank and density currents as a result of temperature and suspended solids influences the fluid mechanics of the tank and can result in significant deviations from ideal flow. A two-dimensional radial flow model was proposed which incorporated the effect of density currents resulting from temperature and suspended solids differentials within the tank. The numerical model predicted the steady-state, layer-averaged radial flow and layer depth. The model solution and field data showed that the momentum and suspended solids of the inflow caused a density current that moved along the clarifier bottom. In the winter, this density current rose as a result of warm inflow water after the initial momentum had decreased and the suspended solids had settled. Close

• 2. [Article] Pend Oreille River Model: Model Scenario Simulations

  The Idaho Department of Environmental Quality is interested in developing a temperature and water quality Total Maximum Daily Load (TMDL) allocation for the Pend Oreille River between the Long Bridge near ...

  Citation × Citation Citation Abstract Copy Title: Pend Oreille River Model: Model Scenario Simulations Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2007 The Idaho Department of Environmental Quality is interested in developing a temperature and water quality Total Maximum Daily Load (TMDL) allocation for the Pend Oreille River between the Long Bridge near the historical Lake Pend Oreille outlet and Albeni Falls Dam (U.S. Army Corps of Engineer’s reservoir) as shown in Figure 1. This management scenario report is an update of a prior report. The management scenarios had to be rerun because of a modeling error made with the outflows rate of Albeni Falls Dam. The new calibration error statistics were compared with the old statistics in Appendix B: Model Calibration Statistics. The model error for vertical profiles was slightly improved while the error for continuous temperature data was approximately the same. Title: Pend Oreille River Model: Model Scenario Simulations Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2007 The Idaho Department of Environmental Quality is interested in developing a temperature and water quality Total Maximum Daily Load (TMDL) allocation for the Pend Oreille River between the Long Bridge near the historical Lake Pend Oreille outlet and Albeni Falls Dam (U.S. Army Corps of Engineer’s reservoir) as shown in Figure 1. This management scenario report is an update of a prior report. The management scenarios had to be rerun because of a modeling error made with the outflows rate of Albeni Falls Dam. The new calibration error statistics were compared with the old statistics in Appendix B: Model Calibration Statistics. The model error for vertical profiles was slightly improved while the error for continuous temperature data was approximately the same. Close

• 3. [Article] The Bull Run River–Reservoir System Model

  The Bull Run watershed is located 41.8 kilometers east of Portland, Oregon in the Mt. Hood National Forest and consists of two reservoirs supplying drinking water to over 840,000 people in the Portland ...

  Citation × Citation Citation Abstract Copy Title: The Bull Run River–Reservoir System Model Author: Annear, Robert Leslie, Wells, Scott A. Year: 2002 The Bull Run watershed is located 41.8 kilometers east of Portland, Oregon in the Mt. Hood National Forest and consists of two reservoirs supplying drinking water to over 840,000 people in the Portland metropolitan area. In March 1998 Steelhead and Spring Chinook were listed as threatened in the Lower Columbia basin under the Endangered Species Act. Historical reservoir operations during the summer released no water downstream resulting in stream temperatures exceeding the state water quality standard for salmonids. CE-QUAL-W2 Version 3 is a two-dimensional water quality and hydrodynamic model capable of modeling watersheds with interconnected rivers, reservoirs and estuaries. CE-QUAL-W2 Version 3 was used to model temperature in the reservoirs and river to investigate management strategies to meet water demand and fish habitat requirements. Management strategies evaluated included adding selective withdrawal, increasing reservoir size, constructing a new water supply reservoir, and altering selective withdrawal operations from historical patterns. Title: The Bull Run River–Reservoir System Model Author: Annear, Robert Leslie, Wells, Scott A. Year: 2002 The Bull Run watershed is located 41.8 kilometers east of Portland, Oregon in the Mt. Hood National Forest and consists of two reservoirs supplying drinking water to over 840,000 people in the Portland metropolitan area. In March 1998 Steelhead and Spring Chinook were listed as threatened in the Lower Columbia basin under the Endangered Species Act. Historical reservoir operations during the summer released no water downstream resulting in stream temperatures exceeding the state water quality standard for salmonids. CE-QUAL-W2 Version 3 is a two-dimensional water quality and hydrodynamic model capable of modeling watersheds with interconnected rivers, reservoirs and estuaries. CE-QUAL-W2 Version 3 was used to model temperature in the reservoirs and river to investigate management strategies to meet water demand and fish habitat requirements. Management strategies evaluated included adding selective withdrawal, increasing reservoir size, constructing a new water supply reservoir, and altering selective withdrawal operations from historical patterns. Close

• 4. [Article] Willamette River and Columbia River Waste Load Allocation Model

  A hydrodynamic and water quality model of the Lower Willamette River was developed to evaluate management alternatives designed to improve water quality. The Lower Willamette River is located in Oregon ...

  Citation × Citation Citation Abstract Copy Title: Willamette River and Columbia River Waste Load Allocation Model Author: Berger, Chris, Annear, Robert Leslie, Wells, Scott A. Year: 2002 A hydrodynamic and water quality model of the Lower Willamette River was developed to evaluate management alternatives designed to improve water quality. The Lower Willamette River is located in Oregon and drains a watershed covering 11500 square miles consisting of forested, agricultural, and urban lands. Inflows include treated municipal wastes and industrial effluents along with non-point sources from agricultural, silvicultural and urbanized land. The model was designed to address temperature, dissolved oxygen, algae, pH and bacteria concerns. The Corps of Engineers two-dimensional, laterally averaged, hydrodynamic and water quality model CE-QUAL-W2, Version 3 was applied. CE-QUAL-W2 consists of directly coupled hydrodynamic and water quality transport models and simulates parameters such as temperature, algae concentration, dissolved oxygen concentration, pH, nutrient concentrations and residence time. The model domain covers a total of about 126 river miles, including the Lower Willamette River from its intersection with the Columbia River upstream to Canby Ferry (RM 35.0) and the Columbia River from Bonneville Dam (RM 144.5) to Beaver Army Terminal (River Mile 53.8). Modeling of the Columbia River was necessary to simulate tidal fluctuations and influxes of Columbia River water into the Lower Willamette. Major tributaries and major NPDES point sources were point inflows to the system model. The ability to model multiple water bodies was a feature of CE-QUAL-W2 Version 3 and allows the simulation of river, reservoir or estuary sections with varying bottom slopes separated by dams and other hydraulic structures. The model was calibrated for the summers of 1993, 1994, 1997, 1998, and 1999. Hydrodynamics were calibrated first followed by temperature and water quality. Root mean square error of model water level predictions was generally less than 0.05 m. Because of the short residence time within the model domain, the development of accurate boundary conditions was essential for good model calibration. Title: Willamette River and Columbia River Waste Load Allocation Model Author: Berger, Chris, Annear, Robert Leslie, Wells, Scott A. Year: 2002 A hydrodynamic and water quality model of the Lower Willamette River was developed to evaluate management alternatives designed to improve water quality. The Lower Willamette River is located in Oregon and drains a watershed covering 11500 square miles consisting of forested, agricultural, and urban lands. Inflows include treated municipal wastes and industrial effluents along with non-point sources from agricultural, silvicultural and urbanized land. The model was designed to address temperature, dissolved oxygen, algae, pH and bacteria concerns. The Corps of Engineers two-dimensional, laterally averaged, hydrodynamic and water quality model CE-QUAL-W2, Version 3 was applied. CE-QUAL-W2 consists of directly coupled hydrodynamic and water quality transport models and simulates parameters such as temperature, algae concentration, dissolved oxygen concentration, pH, nutrient concentrations and residence time. The model domain covers a total of about 126 river miles, including the Lower Willamette River from its intersection with the Columbia River upstream to Canby Ferry (RM 35.0) and the Columbia River from Bonneville Dam (RM 144.5) to Beaver Army Terminal (River Mile 53.8). Modeling of the Columbia River was necessary to simulate tidal fluctuations and influxes of Columbia River water into the Lower Willamette. Major tributaries and major NPDES point sources were point inflows to the system model. The ability to model multiple water bodies was a feature of CE-QUAL-W2 Version 3 and allows the simulation of river, reservoir or estuary sections with varying bottom slopes separated by dams and other hydraulic structures. The model was calibrated for the summers of 1993, 1994, 1997, 1998, and 1999. Hydrodynamics were calibrated first followed by temperature and water quality. Root mean square error of model water level predictions was generally less than 0.05 m. Because of the short residence time within the model domain, the development of accurate boundary conditions was essential for good model calibration. Close

• 5. [Article] CE-QUAL-W2, Version 3

  CE-QUAL-W2 is a two-dimensional water quality and hydrodynamic code supported by the U.S. Army Engineer Research and Development Center (Cole and Buchak 1995). The model has been widely applied to stratified ...

  Citation × Citation Citation Abstract Copy Title: CE-QUAL-W2, Version 3 Author: Wells, Scott A., Cole, Thomas M. Year: 2000 CE-QUAL-W2 is a two-dimensional water quality and hydrodynamic code supported by the U.S. Army Engineer Research and Development Center (Cole and Buchak 1995). The model has been widely applied to stratified surface water systems such as lakes, reservoirs, and estuaries and computes water levels, horizontal and vertical velocities, temperature, and 21 other water quality parameters (such as dissolved oxygen, nutrients, organic matter, algae, pH, the carbonate cycle, bacteria, and dissolved and suspended solids). A typical model grid is shown in Figure 1 where the vertical axis is aligned with gravity. This technical note documents the development of CE-QUAL-W2, Version 3, which incorporates sloping riverine sections. Version 3 has the capability of modeling entire river basins with rivers and interconnected lakes, reservoirs, and/or estuaries. Four example applications illustrate the use of Version 3. Title: CE-QUAL-W2, Version 3 Author: Wells, Scott A., Cole, Thomas M. Year: 2000 CE-QUAL-W2 is a two-dimensional water quality and hydrodynamic code supported by the U.S. Army Engineer Research and Development Center (Cole and Buchak 1995). The model has been widely applied to stratified surface water systems such as lakes, reservoirs, and estuaries and computes water levels, horizontal and vertical velocities, temperature, and 21 other water quality parameters (such as dissolved oxygen, nutrients, organic matter, algae, pH, the carbonate cycle, bacteria, and dissolved and suspended solids). A typical model grid is shown in Figure 1 where the vertical axis is aligned with gravity. This technical note documents the development of CE-QUAL-W2, Version 3, which incorporates sloping riverine sections. Version 3 has the capability of modeling entire river basins with rivers and interconnected lakes, reservoirs, and/or estuaries. Four example applications illustrate the use of Version 3. Close