Nick Voichick, (Former Employee) (Former Employee)
Science and Products
River Sediment Dynamics
Sediment controls the physical habitat of river ecosystems. Changes in the amount and areal distribution of different sediment types cause changes in river-channel form and river habitat. The amount and type of sediment suspended in the water column determines water clarity. Understanding sediment transport and the conditions under which sediment is deposited or eroded from the various...
Lake Powell Research
Lake Powell is a large arid reservoir that represents about 70% of the water storage capacity for the Upper Colorado River Basin. It is the second largest reservoir in the United States by capacity (second only to Lake Mead). Lake Powell is an oligotrophic reservoir, which means that nutrient concentrations and algal production are generally low. This often results in very clear-water conditions...
Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River
Algae, phytoplankton, and rooted macrophytes represent the base of many aquatic food webs and are known as primary producers. Through photosynthesis, these organisms convert sunlight energy into chemical energy (i.e., carbon) that in turn fuels the growth of animals such as macroinvertebrates and fish. This project uses high frequency measurements of dissolved oxygen, which is a by-product of...
Phosphorus, nitrogen, carbon, calcium, pH, and dissolved oxygen data from incubations of Colorado River water and sediment and associated ambient river water measurements
Lake Powell retains most of the phosphorus that it receives, leading to downstream phosphorus limitation. These data were compiled to examine controls on phosphorus cycling below Lake Powell in the Colorado River and from storm inputs from the Paria River. Objectives of our study were to determine how several forms of phosphorus, both organic and inorganic, were cycled under varying...
Gross primary production estimates and associated light, sediment, and water quality data from the Colorado River below Glen Canyon Dam
These data were compiled to model the effects of flow regime and bed grain size distributions on rates of gross primary production (GPP) in the Colorado River below Glen Canyon Dam, AZ, USA. The objectives of our study were to quantify daily and weekly scale effects of an experimental flow regime on GPP in the Colorado River. The experimental flow was conducted at Glen Canyon Dam from...
Laboratory experiment dataturbidity response to increasing silt and clay concentration
These data were compiled during a laboratory experiment showing the turbidity response to increasing silt and clay concentration. The sediment used for the laboratory experiment was collected in the Grand Canyon study area, from the bank of the Little Colorado River, approximately 1 kilometer upstream from its confluence with the Colorado River. The sediment was passed through a 63 m...
Filter Total Items: 14
Proceedings of the Fiscal Year 2022 Annual Reporting Meeting to the Glen Canyon Dam Adaptive Management Program
(Hartwell) This report is prepared primarily to account for work conducted and products delivered in FY 2022 by GCMRC and to inform the Technical Work Group of science conducted by GCMRC and its cooperators in support of the Glen Canyon Dam Adaptive Management Program (GCDAMP). It includes a summary of accomplishments, modifications to work plans, results, and recommendations related to...
Authors
David Topping, Paul E. Grams, Emily C. Palmquist, Joel B. Sankey, Helen Fairley, Bridget Deemer, Charles B. Yackulic, Theodore A. Kennedy, Anya N. Metcalfe, Maria C. Dzul, David Ward, Mariah Aurelia Giardina, Lucas S. Bair, Tom Gushue, Caitlin M. Andrews, Ronald E. Griffiths, David Dean, Keith A. Kohl, Michael J. Moran, Nicholas Voichick, Thomas A. Sabol, Laura A. Tennant, Kimberley Dibble, Michael Runge
Appendix 1: Lake Powell water quality monitoring
No abstract available.
Authors
Bridget Deemer, Nicholas Voichick, Thomas A. Sabol, Caitlin M. Andrews, Bryce Anthony Mihalevich
Over half a century record of limnology data from Lake Powell, desert southwest United States: From reservoir filling to present day (1964–2021)
Lake Powell is a large water storage reservoir in the arid southwestern United States. Here, we present a 58-yr limnology dataset that captures water quality parameters from reservoir filling to present day (temperature, salinity, major ions, total suspended solids), as well as a 38-yr record of Secchi depth, and a ~ 30-yr record of nutrients, phytoplankton, and zooplankton assemblages...
Authors
Bridget Deemer, Caitlin M. Andrews, Kristin E. Strock, Nicholas Voichick, James Hensleigh, John R. Beaver, Robert Radtke
Experimental reductions in sub-daily flow fluctuations increased gross primary productivity for 425 river kilometers downstream
Aquatic primary production is the foundation of many river food webs. Dams change the physical template of rivers, often driving food webs toward greater reliance on aquatic primary production. Nonetheless, the effects of regulated flow regimes on primary production are poorly understood. Load following is a common dam flow management strategy that involves sub-daily changes in water...
Authors
Bridget Deemer, Charles B. Yackulic, Robert W. Hall, Michael J. Dodrill, Theodore A. Kennedy, Jeffrey D. Muehlbauer, David Topping, Nicholas Voichick, Michael D. Yard
Optimal timing of high-flow experiments for sandbar deposition
Sediment-transport theory and field measurements indicate that the greatest or most efficient deposition of sand in eddies occurs during controlled floods (a.k.a. High-Flow Experiments or HFEs) when the greatest amount of the finest sand is available on the bed of the Colorado River (Topping and others, 2010). Conducting HFEs when the sand on the bed of the Colorado River is depleted and...
Authors
David Topping, Paul E. Grams, Ronald E. Griffiths, Joseph E. Hazel, Matthew A. Kaplinski, David Dean, Nicholas Voichick, Joel Unema, Thomas A. Sabol
Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations
Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water...
Authors
Nicholas Voichick, David Topping, Ronald E. Griffiths
Water clarity of the Colorado River—Implications for food webs and fish communities
The closure of Glen Canyon Dam in 1963 resulted in drastic changes to water clarity, temperature, and flow of the Colorado River in Glen, Marble, and Grand Canyons. The Colorado River is now much clearer, water temperature is less variable throughout the year, and the river is much colder in the summer months. The flow—regulated by the dam—is now less variable annually, but has larger...
Authors
Nicholas Voichick, Theodore A. Kennedy, David Topping, Ronald E. Griffiths, Kyrie Fry
Turbidity, light, temperature, and hydropeaking control primary productivity in the Colorado River, Grand Canyon
Dams and river regulation greatly alter the downstream environment for gross primary production (GPP) because of changes in water clarity, flow, and temperature regimes. We estimated reach-scale GPP in five locations of the regulated Colorado River in Grand Canyon using an open channel model of dissolved oxygen. Benthic GPP dominates in Grand Canyon due to fast transport times and low...
Authors
Robert W. Hall, Charles B. Yackulic, Theodore A. Kennedy, Michael D. Yard, Emma J. Rosi-Marshall, Nicholas Voichick, Kathrine E. Behn
Extending the turbidity record: making additional use of continuous data from turbidity, acoustic-Doppler, and laser diffraction instruments and suspended-sediment samples in the Colorado River in Grand Canyon
Turbidity is a measure of the scattering and absorption of light in water, which in rivers is primarily caused by particles, usually sediment, suspended in the water. Turbidity varies significantly with differences in the design of the instrument measuring turbidity, a point that is illustrated in this study by side-by-side comparisons of two different models of instruments. Turbidity...
Authors
Nicholas Voichick, David Topping
Sediment-transport during three controlled-flood experiments on the Colorado River downstream from Glen Canyon Dam, with implications for eddy-sandbar deposition in Grand Canyon National Park
Three large-scale field experiments were conducted on the Colorado River downstream from Glen Canyon Dam in 1996, 2004, and 2008 to evaluate whether artificial (that is, controlled) floods released from the dam could be used in conjunction with the sand supplied by downstream tributaries to rebuild and sustainably maintain eddy sandbars in the river in Grand Canyon National Park. Higher...
Authors
David Topping, David M. Rubin, Paul E. Grams, Ronald E. Griffiths, Thomas A. Sabol, Nicholas Voichick, Robert B. Tusso, Karen M. Vanaman, Richard R. McDonald
Comparison of turbidity to multi-frequency sideways-looking acoustic-Doppler data and suspended-sediment data in the Colorado River in Grand Canyon
Water clarity is important to biologists when studying fish and other fluvial fauna and flora. Turbidity is an indicator of the cloudiness of water, or reduced water clarity, and is commonly measured using nephelometric sensors that record the scattering and absorption of light by particles in the water. Unfortunately, nephelometric sensors only operate over a narrow range of the...
Authors
Nicholas Voichick, David Topping
A simplified water temperature model for the Colorado River below Glen Canyon Dam
Glen Canyon Dam, located on the Colorado River in northern Arizona, has affected the physical, biological and cultural resources of the river downstream in Grand Canyon. One of the impacts to the downstream physical environment that has important implications for the aquatic ecosystem is the transformation of the thermal regime from highly variable seasonally to relatively constant year...
Authors
S.A. Wright, C.R. Anderson, Nicholas Voichick
Science and Products
River Sediment Dynamics
Sediment controls the physical habitat of river ecosystems. Changes in the amount and areal distribution of different sediment types cause changes in river-channel form and river habitat. The amount and type of sediment suspended in the water column determines water clarity. Understanding sediment transport and the conditions under which sediment is deposited or eroded from the various...
Lake Powell Research
Lake Powell is a large arid reservoir that represents about 70% of the water storage capacity for the Upper Colorado River Basin. It is the second largest reservoir in the United States by capacity (second only to Lake Mead). Lake Powell is an oligotrophic reservoir, which means that nutrient concentrations and algal production are generally low. This often results in very clear-water conditions...
Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River
Algae, phytoplankton, and rooted macrophytes represent the base of many aquatic food webs and are known as primary producers. Through photosynthesis, these organisms convert sunlight energy into chemical energy (i.e., carbon) that in turn fuels the growth of animals such as macroinvertebrates and fish. This project uses high frequency measurements of dissolved oxygen, which is a by-product of...
Phosphorus, nitrogen, carbon, calcium, pH, and dissolved oxygen data from incubations of Colorado River water and sediment and associated ambient river water measurements
Lake Powell retains most of the phosphorus that it receives, leading to downstream phosphorus limitation. These data were compiled to examine controls on phosphorus cycling below Lake Powell in the Colorado River and from storm inputs from the Paria River. Objectives of our study were to determine how several forms of phosphorus, both organic and inorganic, were cycled under varying...
Gross primary production estimates and associated light, sediment, and water quality data from the Colorado River below Glen Canyon Dam
These data were compiled to model the effects of flow regime and bed grain size distributions on rates of gross primary production (GPP) in the Colorado River below Glen Canyon Dam, AZ, USA. The objectives of our study were to quantify daily and weekly scale effects of an experimental flow regime on GPP in the Colorado River. The experimental flow was conducted at Glen Canyon Dam from...
Laboratory experiment dataturbidity response to increasing silt and clay concentration
These data were compiled during a laboratory experiment showing the turbidity response to increasing silt and clay concentration. The sediment used for the laboratory experiment was collected in the Grand Canyon study area, from the bank of the Little Colorado River, approximately 1 kilometer upstream from its confluence with the Colorado River. The sediment was passed through a 63 m...
Filter Total Items: 14
Proceedings of the Fiscal Year 2022 Annual Reporting Meeting to the Glen Canyon Dam Adaptive Management Program
(Hartwell) This report is prepared primarily to account for work conducted and products delivered in FY 2022 by GCMRC and to inform the Technical Work Group of science conducted by GCMRC and its cooperators in support of the Glen Canyon Dam Adaptive Management Program (GCDAMP). It includes a summary of accomplishments, modifications to work plans, results, and recommendations related to...
Authors
David Topping, Paul E. Grams, Emily C. Palmquist, Joel B. Sankey, Helen Fairley, Bridget Deemer, Charles B. Yackulic, Theodore A. Kennedy, Anya N. Metcalfe, Maria C. Dzul, David Ward, Mariah Aurelia Giardina, Lucas S. Bair, Tom Gushue, Caitlin M. Andrews, Ronald E. Griffiths, David Dean, Keith A. Kohl, Michael J. Moran, Nicholas Voichick, Thomas A. Sabol, Laura A. Tennant, Kimberley Dibble, Michael Runge
Appendix 1: Lake Powell water quality monitoring
No abstract available.
Authors
Bridget Deemer, Nicholas Voichick, Thomas A. Sabol, Caitlin M. Andrews, Bryce Anthony Mihalevich
Over half a century record of limnology data from Lake Powell, desert southwest United States: From reservoir filling to present day (1964–2021)
Lake Powell is a large water storage reservoir in the arid southwestern United States. Here, we present a 58-yr limnology dataset that captures water quality parameters from reservoir filling to present day (temperature, salinity, major ions, total suspended solids), as well as a 38-yr record of Secchi depth, and a ~ 30-yr record of nutrients, phytoplankton, and zooplankton assemblages...
Authors
Bridget Deemer, Caitlin M. Andrews, Kristin E. Strock, Nicholas Voichick, James Hensleigh, John R. Beaver, Robert Radtke
Experimental reductions in sub-daily flow fluctuations increased gross primary productivity for 425 river kilometers downstream
Aquatic primary production is the foundation of many river food webs. Dams change the physical template of rivers, often driving food webs toward greater reliance on aquatic primary production. Nonetheless, the effects of regulated flow regimes on primary production are poorly understood. Load following is a common dam flow management strategy that involves sub-daily changes in water...
Authors
Bridget Deemer, Charles B. Yackulic, Robert W. Hall, Michael J. Dodrill, Theodore A. Kennedy, Jeffrey D. Muehlbauer, David Topping, Nicholas Voichick, Michael D. Yard
Optimal timing of high-flow experiments for sandbar deposition
Sediment-transport theory and field measurements indicate that the greatest or most efficient deposition of sand in eddies occurs during controlled floods (a.k.a. High-Flow Experiments or HFEs) when the greatest amount of the finest sand is available on the bed of the Colorado River (Topping and others, 2010). Conducting HFEs when the sand on the bed of the Colorado River is depleted and...
Authors
David Topping, Paul E. Grams, Ronald E. Griffiths, Joseph E. Hazel, Matthew A. Kaplinski, David Dean, Nicholas Voichick, Joel Unema, Thomas A. Sabol
Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations
Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water...
Authors
Nicholas Voichick, David Topping, Ronald E. Griffiths
Water clarity of the Colorado River—Implications for food webs and fish communities
The closure of Glen Canyon Dam in 1963 resulted in drastic changes to water clarity, temperature, and flow of the Colorado River in Glen, Marble, and Grand Canyons. The Colorado River is now much clearer, water temperature is less variable throughout the year, and the river is much colder in the summer months. The flow—regulated by the dam—is now less variable annually, but has larger...
Authors
Nicholas Voichick, Theodore A. Kennedy, David Topping, Ronald E. Griffiths, Kyrie Fry
Turbidity, light, temperature, and hydropeaking control primary productivity in the Colorado River, Grand Canyon
Dams and river regulation greatly alter the downstream environment for gross primary production (GPP) because of changes in water clarity, flow, and temperature regimes. We estimated reach-scale GPP in five locations of the regulated Colorado River in Grand Canyon using an open channel model of dissolved oxygen. Benthic GPP dominates in Grand Canyon due to fast transport times and low...
Authors
Robert W. Hall, Charles B. Yackulic, Theodore A. Kennedy, Michael D. Yard, Emma J. Rosi-Marshall, Nicholas Voichick, Kathrine E. Behn
Extending the turbidity record: making additional use of continuous data from turbidity, acoustic-Doppler, and laser diffraction instruments and suspended-sediment samples in the Colorado River in Grand Canyon
Turbidity is a measure of the scattering and absorption of light in water, which in rivers is primarily caused by particles, usually sediment, suspended in the water. Turbidity varies significantly with differences in the design of the instrument measuring turbidity, a point that is illustrated in this study by side-by-side comparisons of two different models of instruments. Turbidity...
Authors
Nicholas Voichick, David Topping
Sediment-transport during three controlled-flood experiments on the Colorado River downstream from Glen Canyon Dam, with implications for eddy-sandbar deposition in Grand Canyon National Park
Three large-scale field experiments were conducted on the Colorado River downstream from Glen Canyon Dam in 1996, 2004, and 2008 to evaluate whether artificial (that is, controlled) floods released from the dam could be used in conjunction with the sand supplied by downstream tributaries to rebuild and sustainably maintain eddy sandbars in the river in Grand Canyon National Park. Higher...
Authors
David Topping, David M. Rubin, Paul E. Grams, Ronald E. Griffiths, Thomas A. Sabol, Nicholas Voichick, Robert B. Tusso, Karen M. Vanaman, Richard R. McDonald
Comparison of turbidity to multi-frequency sideways-looking acoustic-Doppler data and suspended-sediment data in the Colorado River in Grand Canyon
Water clarity is important to biologists when studying fish and other fluvial fauna and flora. Turbidity is an indicator of the cloudiness of water, or reduced water clarity, and is commonly measured using nephelometric sensors that record the scattering and absorption of light by particles in the water. Unfortunately, nephelometric sensors only operate over a narrow range of the...
Authors
Nicholas Voichick, David Topping
A simplified water temperature model for the Colorado River below Glen Canyon Dam
Glen Canyon Dam, located on the Colorado River in northern Arizona, has affected the physical, biological and cultural resources of the river downstream in Grand Canyon. One of the impacts to the downstream physical environment that has important implications for the aquatic ecosystem is the transformation of the thermal regime from highly variable seasonally to relatively constant year...
Authors
S.A. Wright, C.R. Anderson, Nicholas Voichick