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• 341. [Article] Part I : development and application of an arsenic speciation technique using ion-exchange solid phase extraction coupled with GFAAS ; Part II : investigation of zinc amalgam as a reductant

  Two related techniques, based upon ion-exchange solid phase extraction, have been developed for the determination of arsenic speciation. The inorganic arsenic species arsenite (As(III)) and arsenate (As(V)) ...

  Citation × Citation Citation Abstract Copy Title: Part I : development and application of an arsenic speciation technique using ion-exchange solid phase extraction coupled with GFAAS ; Part II : investigation of zinc amalgam as a reductant Author: Bos, Mark C. Two related techniques, based upon ion-exchange solid phase extraction, have been developed for the determination of arsenic speciation. The inorganic arsenic species arsenite (As(III)) and arsenate (As(V)) are separated by anion-exchange and detected with graphite furnace atomic absorption spectrophotometry (GFAAS) with a nickel matrix modifier. The first separation technique, which is based on a published method, utilizes a strong anion-exchange resin in a column format. The method was refined to achieve a cleaner and more rapid separation of the As species. In the second separation technique, the recently available Empore[superscript TM] anion-extraction disks are used. In both cases, rapid separations of several samples are achieved with the use of a vacuum manifold. The simplicity of the separation techniques allows them to be applied in the field which eliminates potential problems due to sample storage. In the pH range of most natural water samples (5-9), As(III) exists as a neutral species which is not retained by the resin, while As(V) exists as a monovalent or divalent species which are subsequently retained by the resin. The two arsenic species are collected in 3 to 4 fractions with As(III) appearing in the first two fractions. The As(V) species is eluted from the resin with 0.1 M HCl and collected in the last one or two fractions. Percent recoveries for each species range from 94 to 99%. The detection limit for each species with GFAAS is 2 μg/L. The speciation techniques were used successfully in several applications. First, the resin technique was used to monitor the oxidation of As(III) by 0₂, H₂0₂, and δ-Mn0₂. The technique was also used to monitor the reduction of As(V) by Fe(II) and in solutions containing combinations of Fe(II), Fe(III), and a scorbic acid. Second, the resin technique was used to monitor the redox behavior of arsenic in soil slurries in bio-reactor systems. Upon spiking the soil slurry to a level of 500 μg/L As(V), 80 to 90% of the As(V) was immediately adsorbed, presumably to hydrous Fe(III) oxides. In general, as conditions became more reducing, total soluble arsenic increased as a result of either abiotic or biotic reduction of the As(V) to the more soluble As(III). Third, the disk technique was applied in the field to determine arsenic speciation in creek water at Sutter Creek, Ca., where homes are built upon a large pile of mine tailings containing arsenic. In the creek water, no As(III) was detected but As(V) was detected at a level of 8 μg/L. Fourth and finally, the resin technique was used to determine arsenic speciation when a sample of the mine tailings was placed in a reactor and combined with a soil slurry thus simulating a flooded condition. As conditions became more reducing, up to 800 μg/L As was detected in solution with As(III) accounting for almost 90% of total soluble species. Also presented here is an investigation of zinc amalgam as a reducing agent for Cr(III) and selected redox indicators. Zinc amalgam, in a column format, also known as the classic Jones Reductor, provides an efficient means for production of Crap and reduced forms of various redox indicators. Finally, the reduction capabilities of Ti(III) citrate and zinc amalgam were compared. Title: Part I : development and application of an arsenic speciation technique using ion-exchange solid phase extraction coupled with GFAAS ; Part II : investigation of zinc amalgam as a reductant Author: Bos, Mark C. Two related techniques, based upon ion-exchange solid phase extraction, have been developed for the determination of arsenic speciation. The inorganic arsenic species arsenite (As(III)) and arsenate (As(V)) are separated by anion-exchange and detected with graphite furnace atomic absorption spectrophotometry (GFAAS) with a nickel matrix modifier. The first separation technique, which is based on a published method, utilizes a strong anion-exchange resin in a column format. The method was refined to achieve a cleaner and more rapid separation of the As species. In the second separation technique, the recently available Empore[superscript TM] anion-extraction disks are used. In both cases, rapid separations of several samples are achieved with the use of a vacuum manifold. The simplicity of the separation techniques allows them to be applied in the field which eliminates potential problems due to sample storage. In the pH range of most natural water samples (5-9), As(III) exists as a neutral species which is not retained by the resin, while As(V) exists as a monovalent or divalent species which are subsequently retained by the resin. The two arsenic species are collected in 3 to 4 fractions with As(III) appearing in the first two fractions. The As(V) species is eluted from the resin with 0.1 M HCl and collected in the last one or two fractions. Percent recoveries for each species range from 94 to 99%. The detection limit for each species with GFAAS is 2 μg/L. The speciation techniques were used successfully in several applications. First, the resin technique was used to monitor the oxidation of As(III) by 0₂, H₂0₂, and δ-Mn0₂. The technique was also used to monitor the reduction of As(V) by Fe(II) and in solutions containing combinations of Fe(II), Fe(III), and a scorbic acid. Second, the resin technique was used to monitor the redox behavior of arsenic in soil slurries in bio-reactor systems. Upon spiking the soil slurry to a level of 500 μg/L As(V), 80 to 90% of the As(V) was immediately adsorbed, presumably to hydrous Fe(III) oxides. In general, as conditions became more reducing, total soluble arsenic increased as a result of either abiotic or biotic reduction of the As(V) to the more soluble As(III). Third, the disk technique was applied in the field to determine arsenic speciation in creek water at Sutter Creek, Ca., where homes are built upon a large pile of mine tailings containing arsenic. In the creek water, no As(III) was detected but As(V) was detected at a level of 8 μg/L. Fourth and finally, the resin technique was used to determine arsenic speciation when a sample of the mine tailings was placed in a reactor and combined with a soil slurry thus simulating a flooded condition. As conditions became more reducing, up to 800 μg/L As was detected in solution with As(III) accounting for almost 90% of total soluble species. Also presented here is an investigation of zinc amalgam as a reducing agent for Cr(III) and selected redox indicators. Zinc amalgam, in a column format, also known as the classic Jones Reductor, provides an efficient means for production of Crap and reduced forms of various redox indicators. Finally, the reduction capabilities of Ti(III) citrate and zinc amalgam were compared. Close

• 342. [Article] Distribution and juvenile ecology of bull trout (Salvelinus confluentus) in the Cascade Mountains

  Distribution and juvenile habitat use of bull trout (Salvelinus confluentus) were surveyed in selected areas of the Upper Willamette, Deschutes, upper Yakima, and upper Cedar River basins in Oregon and Washington ...

  Citation × Citation Citation Abstract Copy Title: Distribution and juvenile ecology of bull trout (Salvelinus confluentus) in the Cascade Mountains Author: Goetz, Frederick Allen Distribution and juvenile habitat use of bull trout (Salvelinus confluentus) were surveyed in selected areas of the Upper Willamette, Deschutes, upper Yakima, and upper Cedar River basins in Oregon and Washington from 1989 to 1991, using day snorkeling, night snorkeling, and electrofishing. These methods were selected after a preliminary diel streamside study of juvenile bull trout showed fry (age 0) counts were significantly higher (P<0.00l) during the day, while counts of juvenile fish (age 1 and 2) were significantly higher (P<0.00l) at night. The highest counts of juveniles occurred during a "quiet period" immediately after dusk, during which time fish were inactive, out of cover, and easily counted with underwater flashlights. In a comparison of four sampling methods on Jack Creek, electrofishing was significantly correlated (P<0.05) with day (r=0.8l) and night (r=0.89) snorkeling counts, but not with streambank counts. In a comparison of day and night snorkeling in 10 streams, total density estimates were significantly greater (P<0.0l) for night snorkeling than day. The diel study and sampling methods comparison suggested surveys of distribution and habitat use of bull trout should include night surveys as well as day. Distribution surveys found that, except for one stream, juvenile bull trout were found only in, or near, spring-fed areas created by recent lava flows. Presence of bull trout in a stream was related to cold groundwater temperatures, as they were not found in streams with temperatures above 14°C. Distribution of bull trout in Oregon and Washington followed a pattern of decreasing elevation with increasing latitude and longitude(Ra=-0.9l6) Presence at lower than expected elevations were explained when groundwater temperatures were predicted from mean annual air temperatures. Actual water temperatures for these spring-fed streams were significantly lower (p<0.00l) than predicted based on elevation, latitude, and longitude. Comparison of historical distribution of bull trout showed extant bull trout were found in the Willamette and Deschutes River Basins of Oregon, respectively, in only 26.2 and 56.2% of their former ranges. Factors associated with bull trout demise in Oregon Cascade streams were (1) isolation and inundation of spring-fed stream habitat by water control structures, (2) introduction of brook trout and brown trout, and (3) large flood events and habitat degradation. Juvenile habitat use was analyzed at the macrohabitat (habitat unit) level in five river basins. Diel and seasonal microhabitat use was also documented for one spring-fed stream, Jack Creek. There was a clear difference in habitat use day and night, associated with the low water temperature of the spring-fed streams (mean=8.0°C). All habitat unit types (pool, riffle, glide, side channel) were used day and night, but bull trout only elected to use side channels in both time periods. Bull trout were found at night in (1) a higher percentage of habitat units, (2) in higher densities by unit, and (3) in increasing numbers with increasing habitat unit area. In Jack Creek, bull trout elected to use shallow water depths, low mean velocities, instream woody debris, and small substrates. Title: Distribution and juvenile ecology of bull trout (Salvelinus confluentus) in the Cascade Mountains Author: Goetz, Frederick Allen Distribution and juvenile habitat use of bull trout (Salvelinus confluentus) were surveyed in selected areas of the Upper Willamette, Deschutes, upper Yakima, and upper Cedar River basins in Oregon and Washington from 1989 to 1991, using day snorkeling, night snorkeling, and electrofishing. These methods were selected after a preliminary diel streamside study of juvenile bull trout showed fry (age 0) counts were significantly higher (P<0.00l) during the day, while counts of juvenile fish (age 1 and 2) were significantly higher (P<0.00l) at night. The highest counts of juveniles occurred during a "quiet period" immediately after dusk, during which time fish were inactive, out of cover, and easily counted with underwater flashlights. In a comparison of four sampling methods on Jack Creek, electrofishing was significantly correlated (P<0.05) with day (r=0.8l) and night (r=0.89) snorkeling counts, but not with streambank counts. In a comparison of day and night snorkeling in 10 streams, total density estimates were significantly greater (P<0.0l) for night snorkeling than day. The diel study and sampling methods comparison suggested surveys of distribution and habitat use of bull trout should include night surveys as well as day. Distribution surveys found that, except for one stream, juvenile bull trout were found only in, or near, spring-fed areas created by recent lava flows. Presence of bull trout in a stream was related to cold groundwater temperatures, as they were not found in streams with temperatures above 14°C. Distribution of bull trout in Oregon and Washington followed a pattern of decreasing elevation with increasing latitude and longitude(Ra=-0.9l6) Presence at lower than expected elevations were explained when groundwater temperatures were predicted from mean annual air temperatures. Actual water temperatures for these spring-fed streams were significantly lower (p<0.00l) than predicted based on elevation, latitude, and longitude. Comparison of historical distribution of bull trout showed extant bull trout were found in the Willamette and Deschutes River Basins of Oregon, respectively, in only 26.2 and 56.2% of their former ranges. Factors associated with bull trout demise in Oregon Cascade streams were (1) isolation and inundation of spring-fed stream habitat by water control structures, (2) introduction of brook trout and brown trout, and (3) large flood events and habitat degradation. Juvenile habitat use was analyzed at the macrohabitat (habitat unit) level in five river basins. Diel and seasonal microhabitat use was also documented for one spring-fed stream, Jack Creek. There was a clear difference in habitat use day and night, associated with the low water temperature of the spring-fed streams (mean=8.0°C). All habitat unit types (pool, riffle, glide, side channel) were used day and night, but bull trout only elected to use side channels in both time periods. Bull trout were found at night in (1) a higher percentage of habitat units, (2) in higher densities by unit, and (3) in increasing numbers with increasing habitat unit area. In Jack Creek, bull trout elected to use shallow water depths, low mean velocities, instream woody debris, and small substrates. Close

• 343. [Article] An evaluation of planning for water quality control in the Willamette River Basin

  It is no longer possible in any area of the United States to formulate water resources plans for single purpose projects as has been done in past years. No longer can one of our greatest natural resources, water, ...

  Citation × Citation Citation Abstract Copy Title: An evaluation of planning for water quality control in the Willamette River Basin Author: Kirkpatrick, Kenton It is no longer possible in any area of the United States to formulate water resources plans for single purpose projects as has been done in past years. No longer can one of our greatest natural resources, water, be used solely for navigation, power generation, irrigation, or controlled for reducing floods. This resource must now serve a multitude of purposes in our society. Determining the present status of our water resources, what the future requirements will be, how to plan for these future needs, and implementation of these plans represents a major undertaking of local, State, and Federal authorities having interests in this field. In the Pacific Northwest, the Willamette Basin Task Force, acting under the auspices of the Columbia Basin Inter-Agency Committee, has been created to provide the coordinating mechanism for the prosecution of a comprehensive study for the management and development of the water and related land resources of the Willamette River Basin. This study is presently underway. In this thesis, information was collected from individuals associated with the Task Force, from minutes of meetings, and from other publications not readily available, to provide a single document giving the organization and objectives of the Task Force. The National comprehensive planning mechanism was studied to provide background information relating to the evolution of the Task Force and its operation. Water quality control is one of the areas of investigation of the Willamette Basin Task Force. It is directly related to and influenced by the several other multiple-purpose uses of the basin's water resources. It is this aspect of the comprehensive planning mechanism that has been considered in this thesis to evaluate what progress is being made in planning for present and future water quality control requirements for the basin. The results of this study indicate that additional study will be necessary, after further progress has been made by the Task Force, to fully evaluate the planning procedures and accomplishments of the Task Force. Conclusions indicate problems that have been encountered using this particular approach to water resources comprehensive planning. Various problems in the water pollution phase of the study are discussed. Several research study areas are suggested as a means of solving water quality problems which exist now in the Willamette River Basin and those water quality problems which are anticipated in the future as greater demands are placed on this resource. Title: An evaluation of planning for water quality control in the Willamette River Basin Author: Kirkpatrick, Kenton It is no longer possible in any area of the United States to formulate water resources plans for single purpose projects as has been done in past years. No longer can one of our greatest natural resources, water, be used solely for navigation, power generation, irrigation, or controlled for reducing floods. This resource must now serve a multitude of purposes in our society. Determining the present status of our water resources, what the future requirements will be, how to plan for these future needs, and implementation of these plans represents a major undertaking of local, State, and Federal authorities having interests in this field. In the Pacific Northwest, the Willamette Basin Task Force, acting under the auspices of the Columbia Basin Inter-Agency Committee, has been created to provide the coordinating mechanism for the prosecution of a comprehensive study for the management and development of the water and related land resources of the Willamette River Basin. This study is presently underway. In this thesis, information was collected from individuals associated with the Task Force, from minutes of meetings, and from other publications not readily available, to provide a single document giving the organization and objectives of the Task Force. The National comprehensive planning mechanism was studied to provide background information relating to the evolution of the Task Force and its operation. Water quality control is one of the areas of investigation of the Willamette Basin Task Force. It is directly related to and influenced by the several other multiple-purpose uses of the basin's water resources. It is this aspect of the comprehensive planning mechanism that has been considered in this thesis to evaluate what progress is being made in planning for present and future water quality control requirements for the basin. The results of this study indicate that additional study will be necessary, after further progress has been made by the Task Force, to fully evaluate the planning procedures and accomplishments of the Task Force. Conclusions indicate problems that have been encountered using this particular approach to water resources comprehensive planning. Various problems in the water pollution phase of the study are discussed. Several research study areas are suggested as a means of solving water quality problems which exist now in the Willamette River Basin and those water quality problems which are anticipated in the future as greater demands are placed on this resource. Close

• 344. [Article] Contrasting geomorphic responses to climatic, anthropogenic, and fluvial change across modern to millennial time scales, Clackamas River, Oregon

  Geomorphic change along the lower Clackamas River is occurring at a millennial scale due to climate change; a decadal scale as a result River Mill Dam operation; and at an annual scale since 1996 due to ...

  Citation × Citation Citation Abstract Copy Title: Contrasting geomorphic responses to climatic, anthropogenic, and fluvial change across modern to millennial time scales, Clackamas River, Oregon Author: Wampler, Peter J. Geomorphic change along the lower Clackamas River is occurring at a millennial scale due to climate change; a decadal scale as a result River Mill Dam operation; and at an annual scale since 1996 due to a meander cutoff. Channel response to these three mechanisms is incision. Holocene strath terraces, inset into Pleistocene terraces, are broadly synchronous with other terraces in the Pacific Northwest, suggesting a regional aggradational event at the Pleistocene/Holocene boundary. A maximum incision rate of 4.3 mm/year occurs where the river emerges from the Western Cascade Mountains and decreases to 1.4 mm/year near the river mouth. Tectonic uplift, bedrock erodibility, rapid base-level change downstream, or a systematic decrease in Holocene sediment flux may be contributing to the extremely rapid incision rates observed. The River Island mining site experienced a meander cutoff during flooding in 1996, resulting in channel length reduction of 1,100 meters as the river began flowing through a series of gravel pits. Within two days of the peak flow, 3.5 hectares of land and 105,500 m3 of gravel were eroded from the river bank just above the cutoff location. Reach slope increased from 0.0022 to approximately 0.0035 in the cutoff reach. The knick point from the meander cutoff migrated 2,290 meters upstream between 1996 and 2003, resulting in increased bed load transport, incision of 1 to 2 meters, and rapid water table lowering. Ninety-six percent of the total migration distance occurred during the first winter following meander cutoff. Hydrologic changes below River Mill Dam, completed in 1911, are minimal but a set of dam-induced geomorphic changes, resulting from sediment trapping behind the dam, have occurred. Degradation for 3 km below the dam is reflected by regularly spaced bedrock pools with an average spacing of 250 m, or approximately 3.6 channel widths. Measurable downstream effects include: 1) surface grain-size increase; 2) side channel area reduction; 3) gravel bar erosion and bedrock exposure; 4) lowering of water surface elevations; and 5) channel narrowing. Between 1908 and 2000, water surface elevation dropped an average of 0.8 m for 17 km below the dam, presumably due to bed degradation. Title: Contrasting geomorphic responses to climatic, anthropogenic, and fluvial change across modern to millennial time scales, Clackamas River, Oregon Author: Wampler, Peter J. Geomorphic change along the lower Clackamas River is occurring at a millennial scale due to climate change; a decadal scale as a result River Mill Dam operation; and at an annual scale since 1996 due to a meander cutoff. Channel response to these three mechanisms is incision. Holocene strath terraces, inset into Pleistocene terraces, are broadly synchronous with other terraces in the Pacific Northwest, suggesting a regional aggradational event at the Pleistocene/Holocene boundary. A maximum incision rate of 4.3 mm/year occurs where the river emerges from the Western Cascade Mountains and decreases to 1.4 mm/year near the river mouth. Tectonic uplift, bedrock erodibility, rapid base-level change downstream, or a systematic decrease in Holocene sediment flux may be contributing to the extremely rapid incision rates observed. The River Island mining site experienced a meander cutoff during flooding in 1996, resulting in channel length reduction of 1,100 meters as the river began flowing through a series of gravel pits. Within two days of the peak flow, 3.5 hectares of land and 105,500 m3 of gravel were eroded from the river bank just above the cutoff location. Reach slope increased from 0.0022 to approximately 0.0035 in the cutoff reach. The knick point from the meander cutoff migrated 2,290 meters upstream between 1996 and 2003, resulting in increased bed load transport, incision of 1 to 2 meters, and rapid water table lowering. Ninety-six percent of the total migration distance occurred during the first winter following meander cutoff. Hydrologic changes below River Mill Dam, completed in 1911, are minimal but a set of dam-induced geomorphic changes, resulting from sediment trapping behind the dam, have occurred. Degradation for 3 km below the dam is reflected by regularly spaced bedrock pools with an average spacing of 250 m, or approximately 3.6 channel widths. Measurable downstream effects include: 1) surface grain-size increase; 2) side channel area reduction; 3) gravel bar erosion and bedrock exposure; 4) lowering of water surface elevations; and 5) channel narrowing. Between 1908 and 2000, water surface elevation dropped an average of 0.8 m for 17 km below the dam, presumably due to bed degradation. Close

• 345. [Article] Areal distribution, change, and restoration potential of wetlands within the lower Columbia River riparian zone, 1948-1991

  The lower Columbia River (LCR) riparian zone is rich in habitat diversity. However, the natural beauty and species diversity along the river have increasingly become affected by human activity. This study ...

  Citation × Citation Citation Abstract Copy Title: Areal distribution, change, and restoration potential of wetlands within the lower Columbia River riparian zone, 1948-1991 Author: Allen, Tracy Hunter The lower Columbia River (LCR) riparian zone is rich in habitat diversity. However, the natural beauty and species diversity along the river have increasingly become affected by human activity. This study quantifies the areal extent and degree of wetlands change and associated causes along the LCR over the past 44 years. This research examines the distribution of wetland types and their patterns of change, developing regional models which rank areas most conducive to potential wetland recovery or restoration efforts. The length of the study area totals 234 river kilometers, from the mouth of the Columbia River to Bonneville Dam. The width includes the active channel and an approximately three-kilometer swath on either side of the river. Aerial photography was the primary means for interpreting historical extent of wetlands, using five photo dates (1948, 1961, 1973, 1983, and 1991), based upon their time interval, coverage, and photo quality. For each photo throughout the entire study site, land uses and wetland habitats greater than one hectare were identified and classified. Each classified polygon was digitized and spatially analyzed using a Geographic Information System. This study indicates that wetland habitats which were once contiguously draped upon the linear features of the river are decreasing in size and becoming fragmented. There have been both increases and decreases in specific wetland habitat areas which vary by river reach, even though wetlands have diminished overall. The estuarine section of the LCR experienced a 25% net decrease in wetland area between 1948 and 1991, while the riverine tidal section fostered a 1% increase. The riverine lower perennial section sustained the greatest loss of wetlands, which decreased by 37%. Causes for wetland losses in the estuarine section were largely related to in-water activities, such as channelization, while the causes for declines in the riverine lower perennial section were correlated with rapid urbanization. Wetland increases in the riverine tidal section were generally influenced by significant growth in palustrine and forested wetlands associated with the establishment of wildlife refuges and the incremental increase of upstream flood storage capacity. This research provides a template for identifying degraded or displaced wetlands. Through the use of a GIS, each historical wetland was ranked in either low, moderate, or high categories for restoration potential. GIS technology permits focused, sequentially-refined queries to identify potential restoration or recovery sites. In the estuarine section, 74 historical wetland sites were ranked high for restoration potential, while in the riverine tidal and riverine lower perennial sections, there were 178 and 105, respectively. Overall, these sites represent only 25% of the area occupied by wetlands in 1948. While this study advocates restoration potential, restoration is not a surrogate for responsible ecosystem-wide stewardship of the riparian zone. Restoration will not succeed unless degrading factors are mitigated or eliminated. Title: Areal distribution, change, and restoration potential of wetlands within the lower Columbia River riparian zone, 1948-1991 Author: Allen, Tracy Hunter The lower Columbia River (LCR) riparian zone is rich in habitat diversity. However, the natural beauty and species diversity along the river have increasingly become affected by human activity. This study quantifies the areal extent and degree of wetlands change and associated causes along the LCR over the past 44 years. This research examines the distribution of wetland types and their patterns of change, developing regional models which rank areas most conducive to potential wetland recovery or restoration efforts. The length of the study area totals 234 river kilometers, from the mouth of the Columbia River to Bonneville Dam. The width includes the active channel and an approximately three-kilometer swath on either side of the river. Aerial photography was the primary means for interpreting historical extent of wetlands, using five photo dates (1948, 1961, 1973, 1983, and 1991), based upon their time interval, coverage, and photo quality. For each photo throughout the entire study site, land uses and wetland habitats greater than one hectare were identified and classified. Each classified polygon was digitized and spatially analyzed using a Geographic Information System. This study indicates that wetland habitats which were once contiguously draped upon the linear features of the river are decreasing in size and becoming fragmented. There have been both increases and decreases in specific wetland habitat areas which vary by river reach, even though wetlands have diminished overall. The estuarine section of the LCR experienced a 25% net decrease in wetland area between 1948 and 1991, while the riverine tidal section fostered a 1% increase. The riverine lower perennial section sustained the greatest loss of wetlands, which decreased by 37%. Causes for wetland losses in the estuarine section were largely related to in-water activities, such as channelization, while the causes for declines in the riverine lower perennial section were correlated with rapid urbanization. Wetland increases in the riverine tidal section were generally influenced by significant growth in palustrine and forested wetlands associated with the establishment of wildlife refuges and the incremental increase of upstream flood storage capacity. This research provides a template for identifying degraded or displaced wetlands. Through the use of a GIS, each historical wetland was ranked in either low, moderate, or high categories for restoration potential. GIS technology permits focused, sequentially-refined queries to identify potential restoration or recovery sites. In the estuarine section, 74 historical wetland sites were ranked high for restoration potential, while in the riverine tidal and riverine lower perennial sections, there were 178 and 105, respectively. Overall, these sites represent only 25% of the area occupied by wetlands in 1948. While this study advocates restoration potential, restoration is not a surrogate for responsible ecosystem-wide stewardship of the riparian zone. Restoration will not succeed unless degrading factors are mitigated or eliminated. Close

• 346. [Article] Dynamics of the Columbia River tidal plume

  This dissertation investigates the dynamics of the tidally modulated outflow from the Columbia River mouth using high resolution measurements of velocity, density and turbulent microstructure. At high ...

  Citation × Citation Citation Abstract Copy Title: Dynamics of the Columbia River tidal plume Author: Kilcher, Levi F. This dissertation investigates the dynamics of the tidally modulated outflow from the Columbia River mouth using high resolution measurements of velocity, density and turbulent microstructure. At high tide, flow through the river mouth reverses from flood (onshore) to ebb (offshore). During ebb, buoyant fluid issues from the river mouth and spreads offshore across the ocean surface. This is the Columbia River tidal plume. The fluid velocity of the tidal plume is super-critical (greater than the wavespeed of coastal stratification), which creates a zone of sharp surface velocity convergence at its leading edge, causing a front to form. From early ebb to peak ebb, constant front propagation speed and plume expansion rate are controlled by a linearly increasing volume-flux through the river mouth. Within the plume, turbulence at the plume base is strongly related to the difference between the shear-squared, S², and four times the buoyancy frequency squared, 4N². A parameterization based on the excess shear-squared, S² - 4N², represents Reynolds stress well, indicating that it is driven by Kelvin-Helmholtz instability. During peak ebb of large tides, high volume-flux through the mouth drives high S² - 4N², causing high plume-base stress, which forces significant deceleration of the plume. During smaller tides the volume-flux is smaller, S² - 4N² lower, and the stress too weak to significantly decelerate the plume. During mid-ebb of both small and large ebbs, increasing buoyancy flux from the river mouth raises plume stratification, which suppresses S² - 4N² and stress. As ebb ends, decreasing volume flux and deflection by the Coriolis effect limit plume expansion. This weakens surface velocity convergence, causing the front to diffuse. On longer timescales, plume N² is modulated by changes in river flow; higher river flow causes higher N². During peak ebb of large tides this increase in N² supports higher S², resulting in higher S² - 4N², which causes larger internal stress. These results describe the primary dynamics of the Columbia River tidal plume from front formation to late-ebb, and relate variability in those dynamics to tidal and river-flow forcing. Title: Dynamics of the Columbia River tidal plume Author: Kilcher, Levi F. This dissertation investigates the dynamics of the tidally modulated outflow from the Columbia River mouth using high resolution measurements of velocity, density and turbulent microstructure. At high tide, flow through the river mouth reverses from flood (onshore) to ebb (offshore). During ebb, buoyant fluid issues from the river mouth and spreads offshore across the ocean surface. This is the Columbia River tidal plume. The fluid velocity of the tidal plume is super-critical (greater than the wavespeed of coastal stratification), which creates a zone of sharp surface velocity convergence at its leading edge, causing a front to form. From early ebb to peak ebb, constant front propagation speed and plume expansion rate are controlled by a linearly increasing volume-flux through the river mouth. Within the plume, turbulence at the plume base is strongly related to the difference between the shear-squared, S², and four times the buoyancy frequency squared, 4N². A parameterization based on the excess shear-squared, S² - 4N², represents Reynolds stress well, indicating that it is driven by Kelvin-Helmholtz instability. During peak ebb of large tides, high volume-flux through the mouth drives high S² - 4N², causing high plume-base stress, which forces significant deceleration of the plume. During smaller tides the volume-flux is smaller, S² - 4N² lower, and the stress too weak to significantly decelerate the plume. During mid-ebb of both small and large ebbs, increasing buoyancy flux from the river mouth raises plume stratification, which suppresses S² - 4N² and stress. As ebb ends, decreasing volume flux and deflection by the Coriolis effect limit plume expansion. This weakens surface velocity convergence, causing the front to diffuse. On longer timescales, plume N² is modulated by changes in river flow; higher river flow causes higher N². During peak ebb of large tides this increase in N² supports higher S², resulting in higher S² - 4N², which causes larger internal stress. These results describe the primary dynamics of the Columbia River tidal plume from front formation to late-ebb, and relate variability in those dynamics to tidal and river-flow forcing. Close

• 347. [Article] Surface-subsurface facies and distribution of the Eocene Cowlitz and Hamlet formations, northwest Oregon

  Since 1979, over $114 million of natural gas has been produced at the Mist Gas Field, currently the only commercial gas field in the Pacific Northwest. In the Mist Gas Field, the sandstone-dominated Clark ...

  Citation × Citation Citation Abstract Copy Title: Surface-subsurface facies and distribution of the Eocene Cowlitz and Hamlet formations, northwest Oregon Author: Robertson, Christina Lynn Since 1979, over $114 million of natural gas has been produced at the Mist Gas Field, currently the only commercial gas field in the Pacific Northwest. In the Mist Gas Field, the sandstone-dominated Clark and Wilson member of the upper Eocene Cowlitz Formation is the reservoir and the overlying upper mudstone member of the Cowlitz Formation forms the seal. Surface field maps, lithostratigraphic facies and petrographic analyses of a core of the Cowlitz Formation from the gas field, along with isopach maps and correlation of well logs of the Cowlitz and Hamlet formations in and around the gas field were used to constrain the depositional and diagenetic history of the Cowlitz Formation and bounding volcanic and sedimentary units. The Cowlitz and Hamlet formations were deposited in a volcanically and tectonically active forearc basin during the late Eocene reorganization of the convergent margin of western North America. In outcrops, the Hamlet formation (informal) is a deepening-upwards (transgressive) sequence of a basal rocky coastline basaltic conglomerate, overlying shelfal mollusc-bearing micaceous arkosic sandstone and bathyal mudstone with minor thin turbidite sandstone beds which unconformably overlies "shield" volcanoes of the middle to upper Eocene Tillamook Volcanics. In the Mist Gas Field subsurface, the mudstone-dominated Hamlet formation thins to the south toward the Tillamook Volcanics paleohigh. The sequence boundary between the Cowlitz and Hamlet formations coincides with a series of basalt flows of Grays River volcanics mapped in the subsurface in the northern part of the gas field. These flows pinch out to the south. The Clark and Wilson member of the Cowlitz Formation onlaps this paleohigh at the Mist Gas Field. In southwest Washington, flows of the Grays River volcanics overlie arkosic sandstone of the Cowlitz Formation. The basal facies of the Clark and Wilson member at Mist is a bioturbated mudstone-dominated offshore to lower-shoreface transition unit which grades upwards into hummocky-bedded arkosic micaceous reservoir-quality sandstone with minor lignite beds of a storm wave-influenced delta front facies. Both the lower-shoreface facies and the hummocky-bedded facies thin rapidly in the subsurface onto the Grays River Volcanics paleohigh in the north. The uppermost facies of the Clark and Wilson member, the parallel-bedded facies, was reworked by waves into a shore-parallel barrier bar. The northeast-southwest-trending distributary channel axis suggests paleodispersal from the southwest Washington type locality which is dominated by delta plain and estuarine facies. Following deposition of the Clark and Wilson member, an abrupt transgression (marine flooding surface) occurred and the thick parallel-laminated foraminifera-bearing bioturbated mudstone of the upper member of the Cowlitz Formation was deposited at bathyal water depths. A soft sediment contorted siltstone facies of the upper mudstone member resulted from redeposition of the parallel-laminated mudstone facies of the upper mudstone member. This slumping and redeposition of the late Narizian strata during the early Refugian may be related to normal faulting and horst and graben formation during a regional extensional event that formed the structure at the Mist Gas Field. The Cowlitz Formation is unconformably overlain by the deep marine tuffaceous mudstone and minor graded basaltic conglomerate of the Keasey Formation. This heralded the development of the western Cascade calc-alkaline arc and continuing forearc basaltic (Goble) volcanism. Title: Surface-subsurface facies and distribution of the Eocene Cowlitz and Hamlet formations, northwest Oregon Author: Robertson, Christina Lynn Since 1979, over $114 million of natural gas has been produced at the Mist Gas Field, currently the only commercial gas field in the Pacific Northwest. In the Mist Gas Field, the sandstone-dominated Clark and Wilson member of the upper Eocene Cowlitz Formation is the reservoir and the overlying upper mudstone member of the Cowlitz Formation forms the seal. Surface field maps, lithostratigraphic facies and petrographic analyses of a core of the Cowlitz Formation from the gas field, along with isopach maps and correlation of well logs of the Cowlitz and Hamlet formations in and around the gas field were used to constrain the depositional and diagenetic history of the Cowlitz Formation and bounding volcanic and sedimentary units. The Cowlitz and Hamlet formations were deposited in a volcanically and tectonically active forearc basin during the late Eocene reorganization of the convergent margin of western North America. In outcrops, the Hamlet formation (informal) is a deepening-upwards (transgressive) sequence of a basal rocky coastline basaltic conglomerate, overlying shelfal mollusc-bearing micaceous arkosic sandstone and bathyal mudstone with minor thin turbidite sandstone beds which unconformably overlies "shield" volcanoes of the middle to upper Eocene Tillamook Volcanics. In the Mist Gas Field subsurface, the mudstone-dominated Hamlet formation thins to the south toward the Tillamook Volcanics paleohigh. The sequence boundary between the Cowlitz and Hamlet formations coincides with a series of basalt flows of Grays River volcanics mapped in the subsurface in the northern part of the gas field. These flows pinch out to the south. The Clark and Wilson member of the Cowlitz Formation onlaps this paleohigh at the Mist Gas Field. In southwest Washington, flows of the Grays River volcanics overlie arkosic sandstone of the Cowlitz Formation. The basal facies of the Clark and Wilson member at Mist is a bioturbated mudstone-dominated offshore to lower-shoreface transition unit which grades upwards into hummocky-bedded arkosic micaceous reservoir-quality sandstone with minor lignite beds of a storm wave-influenced delta front facies. Both the lower-shoreface facies and the hummocky-bedded facies thin rapidly in the subsurface onto the Grays River Volcanics paleohigh in the north. The uppermost facies of the Clark and Wilson member, the parallel-bedded facies, was reworked by waves into a shore-parallel barrier bar. The northeast-southwest-trending distributary channel axis suggests paleodispersal from the southwest Washington type locality which is dominated by delta plain and estuarine facies. Following deposition of the Clark and Wilson member, an abrupt transgression (marine flooding surface) occurred and the thick parallel-laminated foraminifera-bearing bioturbated mudstone of the upper member of the Cowlitz Formation was deposited at bathyal water depths. A soft sediment contorted siltstone facies of the upper mudstone member resulted from redeposition of the parallel-laminated mudstone facies of the upper mudstone member. This slumping and redeposition of the late Narizian strata during the early Refugian may be related to normal faulting and horst and graben formation during a regional extensional event that formed the structure at the Mist Gas Field. The Cowlitz Formation is unconformably overlain by the deep marine tuffaceous mudstone and minor graded basaltic conglomerate of the Keasey Formation. This heralded the development of the western Cascade calc-alkaline arc and continuing forearc basaltic (Goble) volcanism. Close

• 348. [Article] Measure 37 report and recommendations to Sen. Floyd J. Prozanski, Jr., Rep. Gregory H. Macpherson, Co-Chairs, Joint Special Committee on Land Use Fairness, 2007 Legislative Session

  In summary, as detailed below in Section III, we recommend the 2007 Legislature put Measure 37 back on the track of fair and honest compensation for all claimants, and corral the threat to Willamette Valley ...

  Citation × Citation Citation Abstract Copy Title: Measure 37 report and recommendations to Sen. Floyd J. Prozanski, Jr., Rep. Gregory H. Macpherson, Co-Chairs, Joint Special Committee on Land Use Fairness, 2007 Legislative Session Author: Atiyeh, Victor, Roberts, Barbara, 1936-, Gray, John D. (John Delton), 1919- In summary, as detailed below in Section III, we recommend the 2007 Legislature put Measure 37 back on the track of fair and honest compensation for all claimants, and corral the threat to Willamette Valley agriculture at the same time, by providing as follows: • Whether in the form of a payment of money or in the form of a waiver, compensation should be based on losses landowners actually experienced; • Waivers approved on that basis should be transferable; • Compensation should be based on the proposal by Oregonians in Action submitted to the Oregon Supreme Court on December 5, 2005 (Appendix A), i.e. compensation should equal the reduction in value caused by the enforcement of a land use regulation at the time of its enforcement, plus interest paid on that loss, from the date of enforcement to the date the claim is filed; • The value of a prohibited development right, like a farm homesite, is compensable, notwithstanding strongly rising farm land market values; • The size of waivers should be based on loss of value, not an arbitrary “cap;” • Compensation should take into account property tax reductions for farm and forest land received since 1974; • A landowner who could build a house when a tract of land was purchased may build a house on that tract today, despite a later adopted land use regulation; • Counties and DLCD should be given an extension of time to process the recent flood of claims; • No “freeze” or “suspension” for filed claims or building permits demanding 2-9 home sites until a statewide vote on the Legislature’s changes to Measure 37; • Filed claims demanding 2-9 lots will be given extensions to amend claims to show reduction in value, and that the waiver sought is equal in value to the owner’s loss; claims and permits may then proceed; • For certain claimants who filed claims and incurred certain expenses, a tax credit could provide for recoupment of documented expenses up to $5,000; • The 28% of claims seeking subdivisions of 10-500 lots or more will be suspended pending voter approval of the Legislature’s adjustments to Measure 37; if the measure is approved, such claims may be amended to show reduction in value as recommended here; • The Legislature should refer modifications to Measure 37 to the September 2007 ballot. In developing this report, we acknowledge assistance provided by Henry R. Richmond, Executive Director, American Land Institute; professors Andrew J. Plantinga and William K. Jaeger, Department of Agricultural and Resource Economics, Oregon State University; and Dr. Sheila M. Martin, Director, and Erik Rundell, Graduate Research Assistant, Institute of Portland Metropolitan Studies, Portland State University. Title: Measure 37 report and recommendations to Sen. Floyd J. Prozanski, Jr., Rep. Gregory H. Macpherson, Co-Chairs, Joint Special Committee on Land Use Fairness, 2007 Legislative Session Author: Atiyeh, Victor, Roberts, Barbara, 1936-, Gray, John D. (John Delton), 1919- In summary, as detailed below in Section III, we recommend the 2007 Legislature put Measure 37 back on the track of fair and honest compensation for all claimants, and corral the threat to Willamette Valley agriculture at the same time, by providing as follows: • Whether in the form of a payment of money or in the form of a waiver, compensation should be based on losses landowners actually experienced; • Waivers approved on that basis should be transferable; • Compensation should be based on the proposal by Oregonians in Action submitted to the Oregon Supreme Court on December 5, 2005 (Appendix A), i.e. compensation should equal the reduction in value caused by the enforcement of a land use regulation at the time of its enforcement, plus interest paid on that loss, from the date of enforcement to the date the claim is filed; • The value of a prohibited development right, like a farm homesite, is compensable, notwithstanding strongly rising farm land market values; • The size of waivers should be based on loss of value, not an arbitrary “cap;” • Compensation should take into account property tax reductions for farm and forest land received since 1974; • A landowner who could build a house when a tract of land was purchased may build a house on that tract today, despite a later adopted land use regulation; • Counties and DLCD should be given an extension of time to process the recent flood of claims; • No “freeze” or “suspension” for filed claims or building permits demanding 2-9 home sites until a statewide vote on the Legislature’s changes to Measure 37; • Filed claims demanding 2-9 lots will be given extensions to amend claims to show reduction in value, and that the waiver sought is equal in value to the owner’s loss; claims and permits may then proceed; • For certain claimants who filed claims and incurred certain expenses, a tax credit could provide for recoupment of documented expenses up to $5,000; • The 28% of claims seeking subdivisions of 10-500 lots or more will be suspended pending voter approval of the Legislature’s adjustments to Measure 37; if the measure is approved, such claims may be amended to show reduction in value as recommended here; • The Legislature should refer modifications to Measure 37 to the September 2007 ballot. In developing this report, we acknowledge assistance provided by Henry R. Richmond, Executive Director, American Land Institute; professors Andrew J. Plantinga and William K. Jaeger, Department of Agricultural and Resource Economics, Oregon State University; and Dr. Sheila M. Martin, Director, and Erik Rundell, Graduate Research Assistant, Institute of Portland Metropolitan Studies, Portland State University. Close

• 349. [Article] Growth, residence, and movement of juvenile Chinook salmon within restored and reference estuarine marsh channels in Salmon River, Oregon.

  Tidal wetland channels provide rearing habitat for juvenile Chinook salmon as they emigrate from freshwater habitat and prepare to enter the ocean. Widespread diking and drainage of estuarine marshes ...

  Citation × Citation Citation Abstract Copy Title: Growth, residence, and movement of juvenile Chinook salmon within restored and reference estuarine marsh channels in Salmon River, Oregon. Author: Hering, David K. Tidal wetland channels provide rearing habitat for juvenile Chinook salmon as they emigrate from freshwater habitat and prepare to enter the ocean. Widespread diking and drainage of estuarine marshes for agricultural and urban development may have contributed to a decline in salmon abundance in the Pacific Northwest, prompting efforts to restore estuarine salmon habitat in the region. I investigated the growth and residence patterns of age-0 Chinook salmon in two blind tidal channels in the Salmon River estuary, Oregon. One channel drained a natural high salt marsh in “reference” condition, and the other channel was in an adjacent salt marsh, restored to tidal inundation in 1996 after being diked and controlled by a tide gate for thirty five years. Recapture of individually marked fish indicated salmon growth rates were similar in the two channels, though growth rates varied more seasonally in the restored site. Average minimum residence times of individual fish were approximately ten days in each channel, and individual salmon were observed up to 79 and 117 days after initial marking in the reference and restored channels, respectively. To characterize movement of age-0 salmon within tidal channels, I tested the feasibility of stationary Passive Integrated Transponder (PIT) detection within a small (approximately 8m wide) tidal channel within the natural marsh system. I found that a stationary PIT detector was an effective tool for monitoring tagged fish movement in a brackish water channel network. Salmon movements in the channel were asymmetrical about high slack tide, with peak movement frequency occurring late during both flood and ebb tide periods. Most movements were in the direction of tidal currents, but 20% of individuals entered the channel against the ebbing tide. Individuals occupied the intertidal channel for a median 4.9 hours and as long as 8.9 hours per tidal cycle, and few were detected moving when water depth was <0.4m. Some individuals used the channel on multiple successive tidal cycles, and others entered intermittently over periods up to 109 days. This research used individual-based fish marking methods to quantify juvenile Chinook salmon behavior and performance within tidal marsh channels, assessing functional equivalence of natural and restored sites and demonstrating the value of such habitats for conservation and restoration of salmon populations. Title: Growth, residence, and movement of juvenile Chinook salmon within restored and reference estuarine marsh channels in Salmon River, Oregon. Author: Hering, David K. Tidal wetland channels provide rearing habitat for juvenile Chinook salmon as they emigrate from freshwater habitat and prepare to enter the ocean. Widespread diking and drainage of estuarine marshes for agricultural and urban development may have contributed to a decline in salmon abundance in the Pacific Northwest, prompting efforts to restore estuarine salmon habitat in the region. I investigated the growth and residence patterns of age-0 Chinook salmon in two blind tidal channels in the Salmon River estuary, Oregon. One channel drained a natural high salt marsh in “reference” condition, and the other channel was in an adjacent salt marsh, restored to tidal inundation in 1996 after being diked and controlled by a tide gate for thirty five years. Recapture of individually marked fish indicated salmon growth rates were similar in the two channels, though growth rates varied more seasonally in the restored site. Average minimum residence times of individual fish were approximately ten days in each channel, and individual salmon were observed up to 79 and 117 days after initial marking in the reference and restored channels, respectively. To characterize movement of age-0 salmon within tidal channels, I tested the feasibility of stationary Passive Integrated Transponder (PIT) detection within a small (approximately 8m wide) tidal channel within the natural marsh system. I found that a stationary PIT detector was an effective tool for monitoring tagged fish movement in a brackish water channel network. Salmon movements in the channel were asymmetrical about high slack tide, with peak movement frequency occurring late during both flood and ebb tide periods. Most movements were in the direction of tidal currents, but 20% of individuals entered the channel against the ebbing tide. Individuals occupied the intertidal channel for a median 4.9 hours and as long as 8.9 hours per tidal cycle, and few were detected moving when water depth was <0.4m. Some individuals used the channel on multiple successive tidal cycles, and others entered intermittently over periods up to 109 days. This research used individual-based fish marking methods to quantify juvenile Chinook salmon behavior and performance within tidal marsh channels, assessing functional equivalence of natural and restored sites and demonstrating the value of such habitats for conservation and restoration of salmon populations. Close

• 350. [Article] Will wetlands restoration plans today still be effective tomorrow? Evaluation of performance of potential wetlands for peak flow reduction in future climate scenarios in the Eagle Creek Watershed, IN

  Global climate change is expected to exaggerate the severity of floods and droughts and increase the frequency of extreme streamflow events in the Midwestern United States. Managing these projected impacts ...

  Citation × Citation Citation Abstract Copy Title: Will wetlands restoration plans today still be effective tomorrow? Evaluation of performance of potential wetlands for peak flow reduction in future climate scenarios in the Eagle Creek Watershed, IN Author: Walters, Kelli M. Global climate change is expected to exaggerate the severity of floods and droughts and increase the frequency of extreme streamflow events in the Midwestern United States. Managing these projected impacts poses a major challenge for water resources, conservation, and land use management. Wetlands have been considered as a conservation strategy and work to increase the capacity of watersheds by storing runoff upstream. The implementation of wetlands, especially in tile-drained agricultural watersheds, can reduce peak flows and help mitigate the anticipated impacts of climate change. The goal of this study was to evaluate the long-term performance of wetlands to reduce peak flows in future climate scenarios in the Eagle Creek Watershed in Indiana, as well as to establish a methodology to incorporate climate change into hydrological models to conduct better long-term land management studies and decisions. The Soil and Water Assessment Tool (SWAT) model was forced with bias corrected climate projections from the North American Regional Climate Change Assessment Program (NARCCAP) to evaluate the impacts of climate change on watershed hydrology and the ability of wetlands to reduce peak flows. Long-term monthly streamflow results predicted a slight increase in streamflow in the winter and a slight decrease in the summer from the past (1971-2000) to future (2041-2070) time periods. About half of the climate realizations produced an increase in the Q05 (5% exceedance flow) value and half a decrease, but all predictions agreed that high flow events will increase in frequency in the winter and decrease in the spring and summer. No-flow events, although found to be over-predicted by the hydrological model, showed an increase from the past to the future for all climate realizations. Results from the wetland analysis showed that if all potential wetlands identified in a previous study are installed in the watershed, maximum peak flow reductions of around 20-50 m³/s for the past and future, as well as decreased frequency of extreme events, can be seen. Wetlands proved to be a robust solution for peak flow reduction, producing consistent reductions across all climate projections for both the past and future time periods. Title: Will wetlands restoration plans today still be effective tomorrow? Evaluation of performance of potential wetlands for peak flow reduction in future climate scenarios in the Eagle Creek Watershed, IN Author: Walters, Kelli M. Global climate change is expected to exaggerate the severity of floods and droughts and increase the frequency of extreme streamflow events in the Midwestern United States. Managing these projected impacts poses a major challenge for water resources, conservation, and land use management. Wetlands have been considered as a conservation strategy and work to increase the capacity of watersheds by storing runoff upstream. The implementation of wetlands, especially in tile-drained agricultural watersheds, can reduce peak flows and help mitigate the anticipated impacts of climate change. The goal of this study was to evaluate the long-term performance of wetlands to reduce peak flows in future climate scenarios in the Eagle Creek Watershed in Indiana, as well as to establish a methodology to incorporate climate change into hydrological models to conduct better long-term land management studies and decisions. The Soil and Water Assessment Tool (SWAT) model was forced with bias corrected climate projections from the North American Regional Climate Change Assessment Program (NARCCAP) to evaluate the impacts of climate change on watershed hydrology and the ability of wetlands to reduce peak flows. Long-term monthly streamflow results predicted a slight increase in streamflow in the winter and a slight decrease in the summer from the past (1971-2000) to future (2041-2070) time periods. About half of the climate realizations produced an increase in the Q05 (5% exceedance flow) value and half a decrease, but all predictions agreed that high flow events will increase in frequency in the winter and decrease in the spring and summer. No-flow events, although found to be over-predicted by the hydrological model, showed an increase from the past to the future for all climate realizations. Results from the wetland analysis showed that if all potential wetlands identified in a previous study are installed in the watershed, maximum peak flow reductions of around 20-50 m³/s for the past and future, as well as decreased frequency of extreme events, can be seen. Wetlands proved to be a robust solution for peak flow reduction, producing consistent reductions across all climate projections for both the past and future time periods. Close