Search

Search Results

• 1. [Article] The Impact of Fine Sediment on Stream Macroinvertebrates in Urban and Rural Oregon Streams

  Urbanization, often characterized by high impervious surface area, can result in excessive inputs of fine sediments into urban streams. Excessive fine sediments can blanket the stream bed filling the interstitial ...

  Citation × Citation Citation Abstract Copy Title: The Impact of Fine Sediment on Stream Macroinvertebrates in Urban and Rural Oregon Streams Author: Hoy, Raymond S. Year: 2001 Urbanization, often characterized by high impervious surface area, can result in excessive inputs of fine sediments into urban streams. Excessive fine sediments can blanket the stream bed filling the interstitial space in the substratum, which may have adverse effects on stream biota. A field survey was conducted in Oregon urban and non-urban basins to investigate the relationship between fine sediments and stream macroinvertebrates. Physical, chemical, and biological data were collected from 59 stream sites in two urban and two rural streams. The stream sites fulfilled a continuous sediment gradient, which ranged from a low of 2% of fine sediment in the substrate to a high of 64% with an average of 22%. The % fines, in Clear Creek (rural basin) was significantly lower than in the urban basins (Johnson Creek and Tryon Creek) (p=0.005). Johnson Creek (mean=23%) had approximately three times more fine sediment than Clear Creek (mean=7%), while Tryon Creek (mean=32%) had nearly five times as much fine sediment as Clear Creek. EPT taxa richness was significantly higher in both rural streams than in both urban streams (p0.05). For example, regression analysis of EPT taxa richness vs. % fine sediments displayed a coefficient of determination (r2) value of 0.2. Other macro invertebrates metrics displayed similar patterns. The lack of significant correlations may be due to the cumulative effect of basin-wide "historical land use past". Past land use activity may have resulted in long-term reductions of sensitive taxa in the basin taxa pool and efforts to improve local habitats may not be quickly colonized by pollution sensitive taxa. Long-term degradation to the urban streams resulted in a relatively homogenous assemblage of macro invertebrates, which may have confounded the quantitative relationship between sediments and macroinvertebrates. This study suggests there is a clear difference between urban and non-urban streams in terms of macro invertebrates, which may be likely due to sediments, but the quantitative relationship between fine sediments and macro invertebrates is weak. Title: The Impact of Fine Sediment on Stream Macroinvertebrates in Urban and Rural Oregon Streams Author: Hoy, Raymond S. Year: 2001 Urbanization, often characterized by high impervious surface area, can result in excessive inputs of fine sediments into urban streams. Excessive fine sediments can blanket the stream bed filling the interstitial space in the substratum, which may have adverse effects on stream biota. A field survey was conducted in Oregon urban and non-urban basins to investigate the relationship between fine sediments and stream macroinvertebrates. Physical, chemical, and biological data were collected from 59 stream sites in two urban and two rural streams. The stream sites fulfilled a continuous sediment gradient, which ranged from a low of 2% of fine sediment in the substrate to a high of 64% with an average of 22%. The % fines, in Clear Creek (rural basin) was significantly lower than in the urban basins (Johnson Creek and Tryon Creek) (p=0.005). Johnson Creek (mean=23%) had approximately three times more fine sediment than Clear Creek (mean=7%), while Tryon Creek (mean=32%) had nearly five times as much fine sediment as Clear Creek. EPT taxa richness was significantly higher in both rural streams than in both urban streams (p0.05). For example, regression analysis of EPT taxa richness vs. % fine sediments displayed a coefficient of determination (r2) value of 0.2. Other macro invertebrates metrics displayed similar patterns. The lack of significant correlations may be due to the cumulative effect of basin-wide "historical land use past". Past land use activity may have resulted in long-term reductions of sensitive taxa in the basin taxa pool and efforts to improve local habitats may not be quickly colonized by pollution sensitive taxa. Long-term degradation to the urban streams resulted in a relatively homogenous assemblage of macro invertebrates, which may have confounded the quantitative relationship between sediments and macroinvertebrates. This study suggests there is a clear difference between urban and non-urban streams in terms of macro invertebrates, which may be likely due to sediments, but the quantitative relationship between fine sediments and macro invertebrates is weak. Close

• 2. [Article] Historical Vegetation of Three Salmon-Bearing Watersheds in the Interior Columbia River Basin

  Land use practices can be a contributing factor to environmental degradation and have been the focus of many ecological studies. One aspect that is less addressed is land use history and the effects that ...

  Citation × Citation Citation Abstract Copy Title: Historical Vegetation of Three Salmon-Bearing Watersheds in the Interior Columbia River Basin Author: Smith, Tyanna Year: 2014 Land use practices can be a contributing factor to environmental degradation and have been the focus of many ecological studies. One aspect that is less addressed is land use history and the effects that past practices, such as logging and grazing, can have on the current landscape. This paper describes research and the synthesis of material on the environmental history and watershed characteristics for three watersheds located within spawning and rearing areas for Chinook salmon in the Grande Ronde River Basin in Northeast Oregon: upper Grande Ronde River, Catherine Creek, and Minam River. The Grande Ronde Basin is critical spawning and rearing habitat for salmonids listed under the Endangered Species Act. The primary historical data sources for reconstructing 19th century stream and riparian conditions are the General Land Office township survey notes from 1863 - 1901. Data about the habitat conditions of the landscape were extracted from notes of each township survey source regarding vegetation, stream crossings, and other features found on the landscape in tabular and spatial forms. Data were organized to describe common stream and riparian conditions for the historical time period using a geographic information system. Watershed basin, Chinook salmon life history, ecoregion and surveyor were analyzed using multivariate techniques to determine which parameters were strongly connected to historical vegetation. Ecoregion had the strongest correlation with plant communities. For future research, these historical data could be compared to current habitat survey data, such as the Oregon Department of Fish & Wildlife’s Aquatic Habitat Inventories, to evaluate the degree of change over time of stream and riparian conditions. Title: Historical Vegetation of Three Salmon-Bearing Watersheds in the Interior Columbia River Basin Author: Smith, Tyanna Year: 2014 Land use practices can be a contributing factor to environmental degradation and have been the focus of many ecological studies. One aspect that is less addressed is land use history and the effects that past practices, such as logging and grazing, can have on the current landscape. This paper describes research and the synthesis of material on the environmental history and watershed characteristics for three watersheds located within spawning and rearing areas for Chinook salmon in the Grande Ronde River Basin in Northeast Oregon: upper Grande Ronde River, Catherine Creek, and Minam River. The Grande Ronde Basin is critical spawning and rearing habitat for salmonids listed under the Endangered Species Act. The primary historical data sources for reconstructing 19th century stream and riparian conditions are the General Land Office township survey notes from 1863 - 1901. Data about the habitat conditions of the landscape were extracted from notes of each township survey source regarding vegetation, stream crossings, and other features found on the landscape in tabular and spatial forms. Data were organized to describe common stream and riparian conditions for the historical time period using a geographic information system. Watershed basin, Chinook salmon life history, ecoregion and surveyor were analyzed using multivariate techniques to determine which parameters were strongly connected to historical vegetation. Ecoregion had the strongest correlation with plant communities. For future research, these historical data could be compared to current habitat survey data, such as the Oregon Department of Fish & Wildlife’s Aquatic Habitat Inventories, to evaluate the degree of change over time of stream and riparian conditions. Close

• 3. [Article] A Study of the Adsorption of Some Atmospheric Gases on Soils of the Willamette Valley River Basin

  Recent work indicates that microorganisms present in soils can remove carbon monoxide from the atmosphere and as such constitutes a major sink. B.E.T. adsorption studies were carried out on representative ...

  Citation × Citation Citation Abstract Copy Title: A Study of the Adsorption of Some Atmospheric Gases on Soils of the Willamette Valley River Basin Author: Quale, Thomas R. Year: 1973 Recent work indicates that microorganisms present in soils can remove carbon monoxide from the atmosphere and as such constitutes a major sink. B.E.T. adsorption studies were carried out on representative soils from the Willamette Valley River Basin in order to determine their adsorptive characteristics for carbon monoxide and other gases. Attempts were made to isolate, through a non-soildestructive sterilization, the adsorptive characteristics of the soil microorganisms as well as of the test soil. The carbon monoxide studies show physical adsorption equivalent to the coverage of a few per cent of the surface area at 25.0° and 76 cm-Hg. Adsorption studies also shows that the soil rather then the microorganisms adsorbs most of the carbon monoxide. On sterilized soil, chemical sorption of oxygen was present and was probably caused by the oxidation of dead or damaged soil microorganisms. Hysteresis effects were present in all adsorption studies at 25.0° and appears to be a characteristic of the constituents of the soil and represents a new and as yet unexplained phenomenon. Title: A Study of the Adsorption of Some Atmospheric Gases on Soils of the Willamette Valley River Basin Author: Quale, Thomas R. Year: 1973 Recent work indicates that microorganisms present in soils can remove carbon monoxide from the atmosphere and as such constitutes a major sink. B.E.T. adsorption studies were carried out on representative soils from the Willamette Valley River Basin in order to determine their adsorptive characteristics for carbon monoxide and other gases. Attempts were made to isolate, through a non-soildestructive sterilization, the adsorptive characteristics of the soil microorganisms as well as of the test soil. The carbon monoxide studies show physical adsorption equivalent to the coverage of a few per cent of the surface area at 25.0° and 76 cm-Hg. Adsorption studies also shows that the soil rather then the microorganisms adsorbs most of the carbon monoxide. On sterilized soil, chemical sorption of oxygen was present and was probably caused by the oxidation of dead or damaged soil microorganisms. Hysteresis effects were present in all adsorption studies at 25.0° and appears to be a characteristic of the constituents of the soil and represents a new and as yet unexplained phenomenon. Close

• 4. [Article] Riparian Shade Assessment and Restoration Priorities Analysis in the Damascus Urban Growth Boundary Expansion Area

  An important component of progressive urban planning is the protection and restoration of riparian environments, particularly in the Pacific Northwest where increasing stream temperatures threaten the ...

  Citation × Citation Citation Abstract Copy Title: Riparian Shade Assessment and Restoration Priorities Analysis in the Damascus Urban Growth Boundary Expansion Area Author: Leferink, Robin K. Year: 2007 An important component of progressive urban planning is the protection and restoration of riparian environments, particularly in the Pacific Northwest where increasing stream temperatures threaten the survival of endangered salmonids and other cold-water biota. Restoration projects are often led by watershed councils or other grassroots organizations with limited resources, and it is essential that these groups have an efficient and effective approach to determine priority areas where their efforts can be directed to achieve the greatest ecological benefit. The purpose of this project was to quantify existing riparian shade levels and identify priority reaches for shade restoration on Clackamas River basin streams in the Damascus area expansion of the Portland, Oregon urban growth boundary. Additionally, potential errors in the Metro Regional Land Information System (RLIS) Lite geographic information system (GIS) coverage of the area’s streams were identified and corrected where possible. Riparian shade levels were quantified through interpretation of digital aerial photographs using GIS. At the start of the shade analysis six 50 m reaches in the study area were surveyed using a spherical densiometer to calibrate the aerial photo interpretation. Following the analysis, the method accuracy was assessed by comparing GIS-derived shade classes with field data from 25 sites in the study area that were surveyed in 2003. Stream reaches were identified and prioritized for restoration based on riparian shade level, presence or absence of late-summer flow (as determined through field investigations), and GISevaluated stream aspect (i.e. the direction of stream flow). Generally, the headwaters were found to have less shade than the downstream areas and many of the headwater reaches were identified as the highest restoration priority. Of the 60.5 km of streams assessed in the riparian shade analysis, 24.7 km were identified as potential restoration reaches based on shade levels and late-summer flow conditions. These 24.7 km were further broken into five priority ranks, with 4.1 km of stream reaches assigned to the highest shade restoration priority class. Potential errors in the GIS stream coverage were identified in conjunction with the riparian shade assessment. Where possible, these errors were corrected based on the aerial photographs. Although in many cases access was limited, a total of 18 site visits were made to verify stream locations. The results of this watershed-scale restoration priorities analysis are being used by Clackamas River Basin Council and others to guide restoration planning in the new urban area. While focusing on the high priority stream reaches identified, restoration managers will also need to consider reach-scale factors including land use plans, riparian continuity, parcel size, and landowner cooperation in the final selection of restoration sites. The GIS stream layer corrections were provided to Metro and to the City of Damascus for use in their 2007 natural resource inventory. Title: Riparian Shade Assessment and Restoration Priorities Analysis in the Damascus Urban Growth Boundary Expansion Area Author: Leferink, Robin K. Year: 2007 An important component of progressive urban planning is the protection and restoration of riparian environments, particularly in the Pacific Northwest where increasing stream temperatures threaten the survival of endangered salmonids and other cold-water biota. Restoration projects are often led by watershed councils or other grassroots organizations with limited resources, and it is essential that these groups have an efficient and effective approach to determine priority areas where their efforts can be directed to achieve the greatest ecological benefit. The purpose of this project was to quantify existing riparian shade levels and identify priority reaches for shade restoration on Clackamas River basin streams in the Damascus area expansion of the Portland, Oregon urban growth boundary. Additionally, potential errors in the Metro Regional Land Information System (RLIS) Lite geographic information system (GIS) coverage of the area’s streams were identified and corrected where possible. Riparian shade levels were quantified through interpretation of digital aerial photographs using GIS. At the start of the shade analysis six 50 m reaches in the study area were surveyed using a spherical densiometer to calibrate the aerial photo interpretation. Following the analysis, the method accuracy was assessed by comparing GIS-derived shade classes with field data from 25 sites in the study area that were surveyed in 2003. Stream reaches were identified and prioritized for restoration based on riparian shade level, presence or absence of late-summer flow (as determined through field investigations), and GISevaluated stream aspect (i.e. the direction of stream flow). Generally, the headwaters were found to have less shade than the downstream areas and many of the headwater reaches were identified as the highest restoration priority. Of the 60.5 km of streams assessed in the riparian shade analysis, 24.7 km were identified as potential restoration reaches based on shade levels and late-summer flow conditions. These 24.7 km were further broken into five priority ranks, with 4.1 km of stream reaches assigned to the highest shade restoration priority class. Potential errors in the GIS stream coverage were identified in conjunction with the riparian shade assessment. Where possible, these errors were corrected based on the aerial photographs. Although in many cases access was limited, a total of 18 site visits were made to verify stream locations. The results of this watershed-scale restoration priorities analysis are being used by Clackamas River Basin Council and others to guide restoration planning in the new urban area. While focusing on the high priority stream reaches identified, restoration managers will also need to consider reach-scale factors including land use plans, riparian continuity, parcel size, and landowner cooperation in the final selection of restoration sites. The GIS stream layer corrections were provided to Metro and to the City of Damascus for use in their 2007 natural resource inventory. Close

• 5. [Article] A Stable Isotopic Investigation of a Polar Desert Hydrologic System, McMurdo Dry Valleys, Antarctica

  The hydrologic system of the coastal McMurdo Dry Valleys, Antarctica, is defined by snow accumulation, glacier melt, stream flow, and retention in closed-basin, ice-covered lakes. During the austral summers ...

  Citation × Citation Citation Abstract Copy Title: A Stable Isotopic Investigation of a Polar Desert Hydrologic System, McMurdo Dry Valleys, Antarctica Author: Gooseff, Michael N., Lyons, W. Berry, McKnight, Diane M., Vaughn, Bruce H., Fountain, Andrew G., Dowling, Carolyn Year: 2006 The hydrologic system of the coastal McMurdo Dry Valleys, Antarctica, is defined by snow accumulation, glacier melt, stream flow, and retention in closed-basin, ice-covered lakes. During the austral summers from 1993-1996 and 1999-2000 to 2002-2003, fresh snow, snow pits, glacier ice, stream water, and lake waters were sampled for the stable isotopes deuterium (D) and 18O in order to resolve sources of meltwater and the interactions among the various hydrologic reservoirs in the dry valleys. This data set provides a survey of the distribution of natural water isotope abundances within the well-defined dry valley hydrologic system in Taylor Valley, which extends 20 km inland from McMurdo Sound. The three major Taylor Valley lakes are not connected to one another hydrologically, and their levels are maintained by glacial meltwater inflow and perennial ice-cover sublimation. At the valley scale, glacial ice, snow, stream, and lake waters become more depleted in delta D with increasing distance from McMurdo Sound (further inland). Snow pack in glacial accumulation zones is heterogeneous, likely a result of varying storm sources (continental versus coastal), and, in general, snow pits, fresh snow samples, and glacier ice are more depleted than stream waters. Within the lake basins, glacial ice source waters are depleted by as much as 111ppm delta D and 20 ppm delta 18O compared to lake waters. These results demonstrate the importance of in-stream fractionation at the valley scale. In-stream fractionation occurs through direct evaporation from the channel and hyporheic exchange with isotopically enriched waters in the near-stream subsurface during transport from the glacial source to lake. Furthermore, the results show that lake waters directly reflect their glacial ice sources, despite fractionation during stream transport. Inter-annual comparisons of lake profiles suggest that lake waters are directly influenced by the isotopic composition and amount of stream flow during a season. Title: A Stable Isotopic Investigation of a Polar Desert Hydrologic System, McMurdo Dry Valleys, Antarctica Author: Gooseff, Michael N., Lyons, W. Berry, McKnight, Diane M., Vaughn, Bruce H., Fountain, Andrew G., Dowling, Carolyn Year: 2006 The hydrologic system of the coastal McMurdo Dry Valleys, Antarctica, is defined by snow accumulation, glacier melt, stream flow, and retention in closed-basin, ice-covered lakes. During the austral summers from 1993-1996 and 1999-2000 to 2002-2003, fresh snow, snow pits, glacier ice, stream water, and lake waters were sampled for the stable isotopes deuterium (D) and 18O in order to resolve sources of meltwater and the interactions among the various hydrologic reservoirs in the dry valleys. This data set provides a survey of the distribution of natural water isotope abundances within the well-defined dry valley hydrologic system in Taylor Valley, which extends 20 km inland from McMurdo Sound. The three major Taylor Valley lakes are not connected to one another hydrologically, and their levels are maintained by glacial meltwater inflow and perennial ice-cover sublimation. At the valley scale, glacial ice, snow, stream, and lake waters become more depleted in delta D with increasing distance from McMurdo Sound (further inland). Snow pack in glacial accumulation zones is heterogeneous, likely a result of varying storm sources (continental versus coastal), and, in general, snow pits, fresh snow samples, and glacier ice are more depleted than stream waters. Within the lake basins, glacial ice source waters are depleted by as much as 111ppm delta D and 20 ppm delta 18O compared to lake waters. These results demonstrate the importance of in-stream fractionation at the valley scale. In-stream fractionation occurs through direct evaporation from the channel and hyporheic exchange with isotopically enriched waters in the near-stream subsurface during transport from the glacial source to lake. Furthermore, the results show that lake waters directly reflect their glacial ice sources, despite fractionation during stream transport. Inter-annual comparisons of lake profiles suggest that lake waters are directly influenced by the isotopic composition and amount of stream flow during a season. Close

• 6. [Article] Climate Change and Freshwater Resources in Oregon

  Climate change will affect various sectors of water resources in Oregon in the 21st century. The observed trends in streamflow show significant declines in September flow and, although not significant, ...

  Citation × Citation Citation Abstract Copy Title: Climate Change and Freshwater Resources in Oregon Author: Chang, Heejun, Jones, Julie Year: 2010 Climate change will affect various sectors of water resources in Oregon in the 21st century. The observed trends in streamflow show significant declines in September flow and, although not significant, increases in March flow in many transient rain-snow basins. These streamflow trends are associated with rising temperature and coincident declines in snowpack in spring in the latter half of the 20th century. While there are no distinct trends in high precipitation events, such events are associated with climate variability such as ENSO and PDO. Effects of ENSO and PDO are more pronounced at the beginning and end of the wet season in the Willamette River basin. The amount and seasonality of water supply is projected to shift as the distribution of precipitation changes and temperatures rise. Higher summer air temperatures accompanied by reduced precipitation are projected to increase evapotranspiration and decrease stream flow in summer. Although there are no distinct spatial patterns of changes in precipitation and temperature across the State in the 21st century (uniform increase in temperature across the region), significant regional variations do exist. The magnitude of change depends on the importance of snow in the current water budget, so projected changes are greater for mountainous regions than for low-elevation areas. Transient rain-snow basins, such as those in the Western Cascade basins, are projected to be more sensitive to these changes in precipitation and temperature. The high Cascade basins that are primarily fed by deep groundwater systems could sustain low flow during summer months. Basins in the east of the Cascades are projected to have low summer flow in a distant future as groundwater recharge declines over time. April 1 snow water equivalent (SWE) will decline and the center timing of runoff will become earlier in transient rain-snow basins as snowpack is projected to decline consistently in the 21st century. These model projections should be viewed with caution for several reasons when considering climate change impacts on water supply in Oregon. First, this chapter shows that few consistent trends in runoff are apparent in streamflow records from Oregon; instead, the direction and magnitude of change in streamflow varies by season, by basin size, and among ecoregions in Oregon. Second, observed streamflow trends (e.g., declining flows in summer, or in September) may be explained by factors that may not be directly related to global climate change. For example, recent low-flow years are attributable to low precipitation years (especially 2001 and 2005) and perhaps to interannual variations in snowpack associated with cyclical variation in ocean temperatures, while long-term decreases in summer flows are attributable to the combination of summer precipitation decline and increasing water withdrawals for consumptive use. Third, model projections do not account for possible resilience and adaptations in natural ecosystems that may alter water use and lead to smaller than expected changes in streamflow. More work is needed on vegetation responses to climate variability, the interactions between soil water and vegetation, and the relationship between streamflow and precipitation (runoff ratios) in large basins. Title: Climate Change and Freshwater Resources in Oregon Author: Chang, Heejun, Jones, Julie Year: 2010 Climate change will affect various sectors of water resources in Oregon in the 21st century. The observed trends in streamflow show significant declines in September flow and, although not significant, increases in March flow in many transient rain-snow basins. These streamflow trends are associated with rising temperature and coincident declines in snowpack in spring in the latter half of the 20th century. While there are no distinct trends in high precipitation events, such events are associated with climate variability such as ENSO and PDO. Effects of ENSO and PDO are more pronounced at the beginning and end of the wet season in the Willamette River basin. The amount and seasonality of water supply is projected to shift as the distribution of precipitation changes and temperatures rise. Higher summer air temperatures accompanied by reduced precipitation are projected to increase evapotranspiration and decrease stream flow in summer. Although there are no distinct spatial patterns of changes in precipitation and temperature across the State in the 21st century (uniform increase in temperature across the region), significant regional variations do exist. The magnitude of change depends on the importance of snow in the current water budget, so projected changes are greater for mountainous regions than for low-elevation areas. Transient rain-snow basins, such as those in the Western Cascade basins, are projected to be more sensitive to these changes in precipitation and temperature. The high Cascade basins that are primarily fed by deep groundwater systems could sustain low flow during summer months. Basins in the east of the Cascades are projected to have low summer flow in a distant future as groundwater recharge declines over time. April 1 snow water equivalent (SWE) will decline and the center timing of runoff will become earlier in transient rain-snow basins as snowpack is projected to decline consistently in the 21st century. These model projections should be viewed with caution for several reasons when considering climate change impacts on water supply in Oregon. First, this chapter shows that few consistent trends in runoff are apparent in streamflow records from Oregon; instead, the direction and magnitude of change in streamflow varies by season, by basin size, and among ecoregions in Oregon. Second, observed streamflow trends (e.g., declining flows in summer, or in September) may be explained by factors that may not be directly related to global climate change. For example, recent low-flow years are attributable to low precipitation years (especially 2001 and 2005) and perhaps to interannual variations in snowpack associated with cyclical variation in ocean temperatures, while long-term decreases in summer flows are attributable to the combination of summer precipitation decline and increasing water withdrawals for consumptive use. Third, model projections do not account for possible resilience and adaptations in natural ecosystems that may alter water use and lead to smaller than expected changes in streamflow. More work is needed on vegetation responses to climate variability, the interactions between soil water and vegetation, and the relationship between streamflow and precipitation (runoff ratios) in large basins. Close

• 7. [Article] The Influence of Floodplain Restoration on Flow and Sediment Dynamics in an Urban River

  A study of floodplain sedimentation on a recently restored floodplain is presented. This study uses a two-dimensional hydro-morphodynamic model for predicting flow and suspended-sediment dynamics in the ...

  Citation × Citation Citation Abstract Copy Title: The Influence of Floodplain Restoration on Flow and Sediment Dynamics in an Urban River Author: Ahilan, Sangaralingam, Guan, Mingfu, Sleigh, Andrew, Wright, Nigel G., Chang, Heejun Year: 2016 A study of floodplain sedimentation on a recently restored floodplain is presented. This study uses a two-dimensional hydro-morphodynamic model for predicting flow and suspended-sediment dynamics in the downstream of Johnson Creek, the East Lents reach, where the bank of the river has been reconfigured to reconnect to a restored floodplain on a 0.26 km2 (26-ha) site. The simulation scenarios include 10-, 50-, 100- and 500-year event-based deposition modelling of flood events and long-term modelling using the 64 historical flood events between 1941 and 2014. Simulation results showed that the restored floodplain significantly attenuates the upstream flood peak by up to 25% at the downstream. Results also indicated that approximately 20%–30% of sediment from the upstream is deposited on the East Lents floodplain. Furthermore, deposited sediment over the simulated period (1941–2014) is approximately 0.1% of the basin's flood storage capacity; however, the reduction in the storage does not offset the overall flood resilience impact of the flood basin. The sediment conservation at the East Lents flood basin as predicted by the model reduces the annual sediment loading of the Johnson Creek by 1% at the confluence with Willamette River, providing both improved water quality and flood resilience further downstream. Title: The Influence of Floodplain Restoration on Flow and Sediment Dynamics in an Urban River Author: Ahilan, Sangaralingam, Guan, Mingfu, Sleigh, Andrew, Wright, Nigel G., Chang, Heejun Year: 2016 A study of floodplain sedimentation on a recently restored floodplain is presented. This study uses a two-dimensional hydro-morphodynamic model for predicting flow and suspended-sediment dynamics in the downstream of Johnson Creek, the East Lents reach, where the bank of the river has been reconfigured to reconnect to a restored floodplain on a 0.26 km2 (26-ha) site. The simulation scenarios include 10-, 50-, 100- and 500-year event-based deposition modelling of flood events and long-term modelling using the 64 historical flood events between 1941 and 2014. Simulation results showed that the restored floodplain significantly attenuates the upstream flood peak by up to 25% at the downstream. Results also indicated that approximately 20%–30% of sediment from the upstream is deposited on the East Lents floodplain. Furthermore, deposited sediment over the simulated period (1941–2014) is approximately 0.1% of the basin's flood storage capacity; however, the reduction in the storage does not offset the overall flood resilience impact of the flood basin. The sediment conservation at the East Lents flood basin as predicted by the model reduces the annual sediment loading of the Johnson Creek by 1% at the confluence with Willamette River, providing both improved water quality and flood resilience further downstream. Close

• 8. [Article] Interview with Rick Bastasch

  Rick Bastasch was interviewed by Michael Rupp and Jim Knight on May 10, 2017. A lifelong Oregonian, Rick Bastasch is the author of "The Oregon Water Handbook" (Oregon State University Press, 2006). He ...

  Citation × Citation Citation Abstract Copy Title: Interview with Rick Bastasch Author: Bastasch, Rick, Rupp, Michael, Knight, James Year: 2017 Rick Bastasch was interviewed by Michael Rupp and Jim Knight on May 10, 2017. A lifelong Oregonian, Rick Bastasch is the author of "The Oregon Water Handbook" (Oregon State University Press, 2006). He worked with the Oregon Water Resources Department for over a decade, specializing in river basin planning, intergovernmental coordination, public information, and legislative analysis. He has also led recent efforts to conserve and restore the Willamette River. Title: Interview with Rick Bastasch Author: Bastasch, Rick, Rupp, Michael, Knight, James Year: 2017 Rick Bastasch was interviewed by Michael Rupp and Jim Knight on May 10, 2017. A lifelong Oregonian, Rick Bastasch is the author of "The Oregon Water Handbook" (Oregon State University Press, 2006). He worked with the Oregon Water Resources Department for over a decade, specializing in river basin planning, intergovernmental coordination, public information, and legislative analysis. He has also led recent efforts to conserve and restore the Willamette River. Close

• 9. [Article] Analyzing Dam Feasibility in the Willamette River Watershed

  This study conducts a dam-scale cost versus benefit analysis in order to explore the feasibility of each the 13 U.S. Army Corps of Engineers (USACE) commissioned dams in Oregon’s Willamette River network. ...

  Citation × Citation Citation Abstract Copy Title: Analyzing Dam Feasibility in the Willamette River Watershed Author: Nagel, Alexander Cameron Year: 2017 This study conducts a dam-scale cost versus benefit analysis in order to explore the feasibility of each the 13 U.S. Army Corps of Engineers (USACE) commissioned dams in Oregon’s Willamette River network. Constructed between 1941 and 1969, these structures function in collaboration to comprise the Willamette River Basin Reservoir System (WRBRS). The motivation for this project derives from a growing awareness of the biophysical impacts that dam structures can have on riparian habitats. This project compares each of the 13 dams being assessed, to prioritize their level of utility within the system. The study takes the metrics from the top three services (flood regulation, hydropower generation and recreation) and disservices (fish mortality, structural risk and water temperature hazards) and creates a rubric that scores the feasibility of each dam within the system. Within a range between 0 to 3 for three dam services and 0 to -4.5 for two disservices, the overall calculated score elucidates for each structure whether its contribution to the WRBRS is positive or negative. Further analysis searches for spatiotemporal trends such as anomalous tributaries or magnified structural risk for structures exceeding a certain age. GIS data from the National Inventory of Dams (NID), U.S. Geologic Survey (USGS) water measurements, raw data from USACE, and peer-reviewed studies comprise the statistics that generate results for this analysis. The computed scores for each dam yield an average overall score of -1.31, and nine of the 13 structures have negative results, indicating that the WRBRS faces challenges going forward. The study seeks to contribute to the increasingly relevant examination of dam networks at the watershed scale. Title: Analyzing Dam Feasibility in the Willamette River Watershed Author: Nagel, Alexander Cameron Year: 2017 This study conducts a dam-scale cost versus benefit analysis in order to explore the feasibility of each the 13 U.S. Army Corps of Engineers (USACE) commissioned dams in Oregon’s Willamette River network. Constructed between 1941 and 1969, these structures function in collaboration to comprise the Willamette River Basin Reservoir System (WRBRS). The motivation for this project derives from a growing awareness of the biophysical impacts that dam structures can have on riparian habitats. This project compares each of the 13 dams being assessed, to prioritize their level of utility within the system. The study takes the metrics from the top three services (flood regulation, hydropower generation and recreation) and disservices (fish mortality, structural risk and water temperature hazards) and creates a rubric that scores the feasibility of each dam within the system. Within a range between 0 to 3 for three dam services and 0 to -4.5 for two disservices, the overall calculated score elucidates for each structure whether its contribution to the WRBRS is positive or negative. Further analysis searches for spatiotemporal trends such as anomalous tributaries or magnified structural risk for structures exceeding a certain age. GIS data from the National Inventory of Dams (NID), U.S. Geologic Survey (USGS) water measurements, raw data from USACE, and peer-reviewed studies comprise the statistics that generate results for this analysis. The computed scores for each dam yield an average overall score of -1.31, and nine of the 13 structures have negative results, indicating that the WRBRS faces challenges going forward. The study seeks to contribute to the increasingly relevant examination of dam networks at the watershed scale. Close

• 10. [Article] Streamflow Modeling of Johnson Creek Subwatersheds Using the Precipitation Runoff Modeling System

  Johnson Creek, in the Portland, Oregon metropolitan region, has several pollutants on the U.S. Environmental Protection Agency’s (EPA) 303(d) list including excess heat, low dissolved oxygen, and harmful ...

  Citation × Citation Citation Abstract Copy Title: Streamflow Modeling of Johnson Creek Subwatersheds Using the Precipitation Runoff Modeling System Author: Malone, Theophilus M Year: 2014 Johnson Creek, in the Portland, Oregon metropolitan region, has several pollutants on the U.S. Environmental Protection Agency’s (EPA) 303(d) list including excess heat, low dissolved oxygen, and harmful bacteria. Understanding streamflow response to precipitation events is an important component to evaluating water quality trends and calculating the Total Maximum Daily Load (TMDL) for pollutants of concern. Investigating the streamflow-precipitation relationship on the subwatershed scale can give insight to the hydrologic response of a given watershed. However, developing rating curves for several subwatersheds can be cost and time prohibitive. The objective of this project was to develop a hydrologic model using the Precipitation Runoff Modeling System (PRMS), developed by the United States Geological Survey (USGS) to validate streamflow estimates for subwatersheds lacking a significant period of record. ESRI’s ArcMap, a geographic information system (GIS), was used to characterize the target drainage basins and extract basin-specific parameters for upper watersheds of Johnson Creek. The Johnson Creek Upper Watershed (JCUW) model was calibrated to an existing streamflow gage at Regner Road, in Gresham, Oregon. Calibrated parameters were substituted into a second PRMS model characterizing the Sunshine Creek Subwatershed, which lies within the JCUW. The Sunshine Creek model was used to validate a flow time-series derived from a pressure transducer and a rating curve. Title: Streamflow Modeling of Johnson Creek Subwatersheds Using the Precipitation Runoff Modeling System Author: Malone, Theophilus M Year: 2014 Johnson Creek, in the Portland, Oregon metropolitan region, has several pollutants on the U.S. Environmental Protection Agency’s (EPA) 303(d) list including excess heat, low dissolved oxygen, and harmful bacteria. Understanding streamflow response to precipitation events is an important component to evaluating water quality trends and calculating the Total Maximum Daily Load (TMDL) for pollutants of concern. Investigating the streamflow-precipitation relationship on the subwatershed scale can give insight to the hydrologic response of a given watershed. However, developing rating curves for several subwatersheds can be cost and time prohibitive. The objective of this project was to develop a hydrologic model using the Precipitation Runoff Modeling System (PRMS), developed by the United States Geological Survey (USGS) to validate streamflow estimates for subwatersheds lacking a significant period of record. ESRI’s ArcMap, a geographic information system (GIS), was used to characterize the target drainage basins and extract basin-specific parameters for upper watersheds of Johnson Creek. The Johnson Creek Upper Watershed (JCUW) model was calibrated to an existing streamflow gage at Regner Road, in Gresham, Oregon. Calibrated parameters were substituted into a second PRMS model characterizing the Sunshine Creek Subwatershed, which lies within the JCUW. The Sunshine Creek model was used to validate a flow time-series derived from a pressure transducer and a rating curve. Close