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• 1. [Article] Engineering a Healthier Watershed: Middle School Students Use Engineering Design to Lessen the Impact of Their Campus' Impervious Surfaces on Their Local Watershed

  It is important that students understand not only how their local watershed functions, but also how it is being impacted by impervious surfaces. Additionally, students need experience exploring the scientific ...

  Citation × Citation Citation Abstract Copy Title: Engineering a Healthier Watershed: Middle School Students Use Engineering Design to Lessen the Impact of Their Campus' Impervious Surfaces on Their Local Watershed Author: Gardner, Elizabeth Claire Year: 2015 It is important that students understand not only how their local watershed functions, but also how it is being impacted by impervious surfaces. Additionally, students need experience exploring the scientific and engineering practices that are necessary for a strong STEM background. With this knowledge students can be empowered to tackle this real and local problem using engineering design, a powerful practice gaining momentum and clarity through its prominence in the recent Framework for K-12 Science Education. Twenty classes of suburban sixth-graders participated in a new five-week Watershed Engineering Design Unit taught by their regular science teachers. Students engaged in scientific inquiry to learn about the structure, function, and health of their local watersheds, focusing on the effects of impervious surfaces. In small groups, students used the engineering design process to propose solutions to lessen the impact of runoff from their school campuses. The goal of this evaluation was to determine the effectiveness of the curriculum in terms of student gains in understanding of (1) watershed function, (2) the impact of impervious surfaces, and (3) the engineering design process. To determine the impact of this curriculum on their learning, students took multiple-choice pre- and post-assessments made up of items covering the three categories above. This data was analyzed for statistical significance using a lower-tailed paired sample t-test. All three objectives showed statistically significant learning gains and the results were used to recommend improvements to the curriculum and the assessment instrument for future iterations. Title: Engineering a Healthier Watershed: Middle School Students Use Engineering Design to Lessen the Impact of Their Campus' Impervious Surfaces on Their Local Watershed Author: Gardner, Elizabeth Claire Year: 2015 It is important that students understand not only how their local watershed functions, but also how it is being impacted by impervious surfaces. Additionally, students need experience exploring the scientific and engineering practices that are necessary for a strong STEM background. With this knowledge students can be empowered to tackle this real and local problem using engineering design, a powerful practice gaining momentum and clarity through its prominence in the recent Framework for K-12 Science Education. Twenty classes of suburban sixth-graders participated in a new five-week Watershed Engineering Design Unit taught by their regular science teachers. Students engaged in scientific inquiry to learn about the structure, function, and health of their local watersheds, focusing on the effects of impervious surfaces. In small groups, students used the engineering design process to propose solutions to lessen the impact of runoff from their school campuses. The goal of this evaluation was to determine the effectiveness of the curriculum in terms of student gains in understanding of (1) watershed function, (2) the impact of impervious surfaces, and (3) the engineering design process. To determine the impact of this curriculum on their learning, students took multiple-choice pre- and post-assessments made up of items covering the three categories above. This data was analyzed for statistical significance using a lower-tailed paired sample t-test. All three objectives showed statistically significant learning gains and the results were used to recommend improvements to the curriculum and the assessment instrument for future iterations. Close

• 2. [Article] A Geospatial Tool for Wetland Prioritization at the Watershed Scale

  There is an increasing demand for assessing ecosystem functions for freshwater wetlands, especially when comparing or prioritizing among wetlands at the watershed scale. We estimated the relative potential ...

  Citation × Citation Citation Abstract Copy Title: A Geospatial Tool for Wetland Prioritization at the Watershed Scale Author: Blackmore, Debra Sue, Chang, Heejun Year: 2015 There is an increasing demand for assessing ecosystem functions for freshwater wetlands, especially when comparing or prioritizing among wetlands at the watershed scale. We estimated the relative potential of selected ecosystem functions for freshwater wetlands within a watershed using widely available geospatial data. We developed four functions to estimate 1) flood storage, 2) late season flow, 3) sediment retention and 4) temperature control in four pilot watersheds in Oregon (Tualatin, Coquille, Upper Grande Ronde and Sprague). These watersheds are geographically separated from each other representing diverse ecoregion environments. Spatial analysis and geographic information system (GIS) were designed for maximum re-use, based on publicly-available data, commonly-used software, semi-automated techniques and wetland characterizations that attempt to capture fundamental wetland processes. Our data sources include 30-meter digital elevation models, NRCS soil survey extracts, USGS National Land Cover Data, USGS HUC8 boundaries (polygons) and statewide wetland delineations (polygons) processed within ArcGIS 10.2 and Python 2.7.5 software. Model parameters were compiled using multiple proxy values for size, slope, aspect, proximity, flow path distance, hydrologic gradient, shade, and soil characteristics. WPT characterizations emphasize the multi-faceted value of freshwater wetlands, relating potential within a watershed as well as providing model-based characterizations between watersheds. Our wetland prioritization tool (WPT) provides useful information to estimate and compare the relative potential for selected wetland functions, thereby improving success in wetland conservation, restoration, and mitigation efforts. Title: A Geospatial Tool for Wetland Prioritization at the Watershed Scale Author: Blackmore, Debra Sue, Chang, Heejun Year: 2015 There is an increasing demand for assessing ecosystem functions for freshwater wetlands, especially when comparing or prioritizing among wetlands at the watershed scale. We estimated the relative potential of selected ecosystem functions for freshwater wetlands within a watershed using widely available geospatial data. We developed four functions to estimate 1) flood storage, 2) late season flow, 3) sediment retention and 4) temperature control in four pilot watersheds in Oregon (Tualatin, Coquille, Upper Grande Ronde and Sprague). These watersheds are geographically separated from each other representing diverse ecoregion environments. Spatial analysis and geographic information system (GIS) were designed for maximum re-use, based on publicly-available data, commonly-used software, semi-automated techniques and wetland characterizations that attempt to capture fundamental wetland processes. Our data sources include 30-meter digital elevation models, NRCS soil survey extracts, USGS National Land Cover Data, USGS HUC8 boundaries (polygons) and statewide wetland delineations (polygons) processed within ArcGIS 10.2 and Python 2.7.5 software. Model parameters were compiled using multiple proxy values for size, slope, aspect, proximity, flow path distance, hydrologic gradient, shade, and soil characteristics. WPT characterizations emphasize the multi-faceted value of freshwater wetlands, relating potential within a watershed as well as providing model-based characterizations between watersheds. Our wetland prioritization tool (WPT) provides useful information to estimate and compare the relative potential for selected wetland functions, thereby improving success in wetland conservation, restoration, and mitigation efforts. Close

• 3. [Article] Assessing Hydrologic and Water Quality Sensitivities to Precipitation Changes, Urban Growth and Land Management Using SWAT

  Precipitation changes and urban growth are two factors altering the state of water quality. Changes in precipitation will alter the amount and timing of flows, and the corresponding sediment and nutrient ...

  Citation × Citation Citation Abstract Copy Title: Assessing Hydrologic and Water Quality Sensitivities to Precipitation Changes, Urban Growth and Land Management Using SWAT Author: Psaris, Alexander Michael Year: 2014 Precipitation changes and urban growth are two factors altering the state of water quality. Changes in precipitation will alter the amount and timing of flows, and the corresponding sediment and nutrient dynamics. Meanwhile, densification associated with urban growth will create more impervious surfaces which will alter sediment and nutrient loadings. Land and water managers often rely on models to develop possible future scenarios and devise management responses to these projected changes. We use the Soil and Water Assessment Tool (SWAT) to assess the sensitivities of stream flow, sediment, and nutrient loads in two urbanizing watersheds in Northwest Oregon, USA to various climate and urbanization scenarios. We evaluate the spatial patterns climate change and urban growth will have on water, sediment and nutrient yields. We also identify critical source areas (CSAs) and investigate how implementation of vegetative filter strips (VFS) could ameliorate the effects of these changes. Our findings suggest that: 1) Water yield is tightly coupled to precipitation. 2) Large increases in winter and spring precipitation provide enough sub-surface storage to increase summertime water yields despite a moderate decrease in summer precipitation. 3) Expansion of urban areas increases surface runoff and has mixed effects on sediment and nutrients. 4) Implementation of VFS reduces pollutant loads helping overall watershed health. This research demonstrates the usefulness of SWAT in facilitating informed land and water management decisions. Title: Assessing Hydrologic and Water Quality Sensitivities to Precipitation Changes, Urban Growth and Land Management Using SWAT Author: Psaris, Alexander Michael Year: 2014 Precipitation changes and urban growth are two factors altering the state of water quality. Changes in precipitation will alter the amount and timing of flows, and the corresponding sediment and nutrient dynamics. Meanwhile, densification associated with urban growth will create more impervious surfaces which will alter sediment and nutrient loadings. Land and water managers often rely on models to develop possible future scenarios and devise management responses to these projected changes. We use the Soil and Water Assessment Tool (SWAT) to assess the sensitivities of stream flow, sediment, and nutrient loads in two urbanizing watersheds in Northwest Oregon, USA to various climate and urbanization scenarios. We evaluate the spatial patterns climate change and urban growth will have on water, sediment and nutrient yields. We also identify critical source areas (CSAs) and investigate how implementation of vegetative filter strips (VFS) could ameliorate the effects of these changes. Our findings suggest that: 1) Water yield is tightly coupled to precipitation. 2) Large increases in winter and spring precipitation provide enough sub-surface storage to increase summertime water yields despite a moderate decrease in summer precipitation. 3) Expansion of urban areas increases surface runoff and has mixed effects on sediment and nutrients. 4) Implementation of VFS reduces pollutant loads helping overall watershed health. This research demonstrates the usefulness of SWAT in facilitating informed land and water management decisions. Close

• 4. [Article] Effects of Tide Gate Replacement on Water Temperature ina Freshwater Slough in the Columbia River Estuary

  Dramatic declines in salmon populations in the Pacific Northwest have brought new attention to the importance of estuarine rearing habitats. Levees and tide gates used to convert estuarine wetlands into ...

  Citation × Citation Citation Abstract Copy Title: Effects of Tide Gate Replacement on Water Temperature ina Freshwater Slough in the Columbia River Estuary Author: Ennis, Sara Year: 2009 Dramatic declines in salmon populations in the Pacific Northwest have brought new attention to the importance of estuarine rearing habitats. Levees and tide gates used to convert estuarine wetlands into farmland have reduced available habitat by more than half of historical levels. Recent efforts to restore estuarine habitats include tide gate replacement, though this method has been poorly studied. As a key indicator of salmon habitat suitability, temperature was used to evaluate the effects of tide gate replacement in a tidally influenced freshwater slough in the Lower Columbia River estuary. Three tide gates in the largest slough on Tenasillahe Island were replaced in 2007 with side-hinged aluminum gates. As managed during the data collection periods, the new tide gates did not allow tidal inflow into the slough. The study employed a Before-After, Control-Impact (BACI) approach, collecting data seasonally two years before and after replacement at the impact site and at the control site, a relatively unaltered slough on nearby Welch Island. Randomized Intervention Analysis and Monte Carlo tests revealed no significant difference in slough water temperatures after tide gate replacement, although minimum temperatures dropped up and downstream of the tide gates. Although the new tide gates did not have a significant effect on water temperature, the lower minimum temperatures may have been caused by a slight increase in tidal circulation. This result suggests that slough temperatures would decrease if the tide gates were managed to increase tidal inflow, and thus improve the quality of salmon rearing habitat. Title: Effects of Tide Gate Replacement on Water Temperature ina Freshwater Slough in the Columbia River Estuary Author: Ennis, Sara Year: 2009 Dramatic declines in salmon populations in the Pacific Northwest have brought new attention to the importance of estuarine rearing habitats. Levees and tide gates used to convert estuarine wetlands into farmland have reduced available habitat by more than half of historical levels. Recent efforts to restore estuarine habitats include tide gate replacement, though this method has been poorly studied. As a key indicator of salmon habitat suitability, temperature was used to evaluate the effects of tide gate replacement in a tidally influenced freshwater slough in the Lower Columbia River estuary. Three tide gates in the largest slough on Tenasillahe Island were replaced in 2007 with side-hinged aluminum gates. As managed during the data collection periods, the new tide gates did not allow tidal inflow into the slough. The study employed a Before-After, Control-Impact (BACI) approach, collecting data seasonally two years before and after replacement at the impact site and at the control site, a relatively unaltered slough on nearby Welch Island. Randomized Intervention Analysis and Monte Carlo tests revealed no significant difference in slough water temperatures after tide gate replacement, although minimum temperatures dropped up and downstream of the tide gates. Although the new tide gates did not have a significant effect on water temperature, the lower minimum temperatures may have been caused by a slight increase in tidal circulation. This result suggests that slough temperatures would decrease if the tide gates were managed to increase tidal inflow, and thus improve the quality of salmon rearing habitat. Close

• 5. [Article] Siltcoos Lake Nonpoint Source Implementation Grant: Water Quality Conditions and Nutrient Sources

  Siltcoos Lake is a large (1280 hectares), shallow (mean depth 3.3 m; maximum depth 6.7 m) lake located on the Central Oregon Coast, just south of Florence and bordered by Dunes City, Oregon. The outflow ...

  Citation × Citation Citation Abstract Copy Title: Siltcoos Lake Nonpoint Source Implementation Grant: Water Quality Conditions and Nutrient Sources Author: Sytsma, Mark D., Miller, Rich Year: 2010 Siltcoos Lake is a large (1280 hectares), shallow (mean depth 3.3 m; maximum depth 6.7 m) lake located on the Central Oregon Coast, just south of Florence and bordered by Dunes City, Oregon. The outflow and water level of Siltcoos Lake is regulated by a dam on the Siltcoos River 4 km upstream from the Pacific. Several permanent streams feed the lake from its 176 square kilometer watershed including Fiddle Creek, Maple Creek, and Woahink Creek, the outflow from Woahink Lake. Much of the watershed is forested and used for timber harvest, residential development, and limited agricultural production. The lake is popular for recreational activities, particularly fishing for wild coastal Coho salmon, rainbow trout, cutthroat trout, largemouth bass, bluegill, crappie, and yellow perch (Buckman 2004). The lake is also the domestic drinking water source for approximately 125 of the 1330 residents of Dunes City and numerous residents outside the city limits within Lane and Douglas Counties (LCOG 2002). During the fall of 2007 a dense bloom of the potentially toxigenic blue-green algal species Anabaena planktonica prompted Dunes City, the South Coast Water District, the Lane County Health Department, and the Oregon Department of Human Services to issue an advisory against usage of Siltcoos Lake water for drinking and other domestic use (DHS 2007). Residents dependent upon Siltcoos Lake were forced to find alternate domestic water sources for a total of 52 days. This incident was part of a long history of water quality problems including dense algal growth and excessive growth of the non-native aquatic macrophytes Brazilian elodea (Egeria densa), parrotsfeather (Myriophyllum aquaticum), and two-leaf water milfoil (Myriophyllum heterophyllum) (Pfauth and Sytsma 2005; Johnson et al. 1985; McHugh 1979). Because of the water quality problems, the Oregon Department of Environmental Quality (DEQ) placed the lake the 303(d) list of impaired water bodies; specifically due to violations of the “aquatic weeds and algae” water quality criterion (DEQ 1998; DEQ 2006). Dunes City has acted on water quality concerns for both Siltcoos and Woahink Lakes by issuing a temporary building moratorium (Dunes City 2006a), a septic tank maintenance ordinance (Dunes City 2006b), and an ordinance limiting phosphorus use (Dunes City 2007). Preliminary assessments (Johnson, et al. 1985, LCOG 2002) indicate multiple sources of water quality problems including excess nutrient and/or sediment loading from residential development, poorly functioning on-site septic systems, private forestry and agricultural practices and introductions of non-native aquatic plant species. This report summarizes data collected by Portland State University and project partners between June 2008 and May 2009 to better define water quality conditions within the lake as well as potential nutrient sources. Physical, chemical, and biological data were collected at lake and tributary sites over the one year period. Data were evaluated across sites, depth and the season. The information collected will contribute to total maximum daily load (TMDL) development for the Midcoast Lakes and can be used to identify and prioritize restoration activities in the Siltcoos Lake watershed. Title: Siltcoos Lake Nonpoint Source Implementation Grant: Water Quality Conditions and Nutrient Sources Author: Sytsma, Mark D., Miller, Rich Year: 2010 Siltcoos Lake is a large (1280 hectares), shallow (mean depth 3.3 m; maximum depth 6.7 m) lake located on the Central Oregon Coast, just south of Florence and bordered by Dunes City, Oregon. The outflow and water level of Siltcoos Lake is regulated by a dam on the Siltcoos River 4 km upstream from the Pacific. Several permanent streams feed the lake from its 176 square kilometer watershed including Fiddle Creek, Maple Creek, and Woahink Creek, the outflow from Woahink Lake. Much of the watershed is forested and used for timber harvest, residential development, and limited agricultural production. The lake is popular for recreational activities, particularly fishing for wild coastal Coho salmon, rainbow trout, cutthroat trout, largemouth bass, bluegill, crappie, and yellow perch (Buckman 2004). The lake is also the domestic drinking water source for approximately 125 of the 1330 residents of Dunes City and numerous residents outside the city limits within Lane and Douglas Counties (LCOG 2002). During the fall of 2007 a dense bloom of the potentially toxigenic blue-green algal species Anabaena planktonica prompted Dunes City, the South Coast Water District, the Lane County Health Department, and the Oregon Department of Human Services to issue an advisory against usage of Siltcoos Lake water for drinking and other domestic use (DHS 2007). Residents dependent upon Siltcoos Lake were forced to find alternate domestic water sources for a total of 52 days. This incident was part of a long history of water quality problems including dense algal growth and excessive growth of the non-native aquatic macrophytes Brazilian elodea (Egeria densa), parrotsfeather (Myriophyllum aquaticum), and two-leaf water milfoil (Myriophyllum heterophyllum) (Pfauth and Sytsma 2005; Johnson et al. 1985; McHugh 1979). Because of the water quality problems, the Oregon Department of Environmental Quality (DEQ) placed the lake the 303(d) list of impaired water bodies; specifically due to violations of the “aquatic weeds and algae” water quality criterion (DEQ 1998; DEQ 2006). Dunes City has acted on water quality concerns for both Siltcoos and Woahink Lakes by issuing a temporary building moratorium (Dunes City 2006a), a septic tank maintenance ordinance (Dunes City 2006b), and an ordinance limiting phosphorus use (Dunes City 2007). Preliminary assessments (Johnson, et al. 1985, LCOG 2002) indicate multiple sources of water quality problems including excess nutrient and/or sediment loading from residential development, poorly functioning on-site septic systems, private forestry and agricultural practices and introductions of non-native aquatic plant species. This report summarizes data collected by Portland State University and project partners between June 2008 and May 2009 to better define water quality conditions within the lake as well as potential nutrient sources. Physical, chemical, and biological data were collected at lake and tributary sites over the one year period. Data were evaluated across sites, depth and the season. The information collected will contribute to total maximum daily load (TMDL) development for the Midcoast Lakes and can be used to identify and prioritize restoration activities in the Siltcoos Lake watershed. Close

• 6. [Article] Continuous Deflection Separation of Stormwater Particulates

  Capture of stormwater particulate matter is of concern to watershed managers trying to meet water quality guidelines by removing toxics associated with particulates from natural water bodies. A laboratory ...

  Citation × Citation Citation Abstract Copy Title: Continuous Deflection Separation of Stormwater Particulates Author: Schwarz, Tracy S., Wells, Scott A. Year: 1999 Capture of stormwater particulate matter is of concern to watershed managers trying to meet water quality guidelines by removing toxics associated with particulates from natural water bodies. A laboratory investigation into particle removal efficiency of a prototype Continuous Deflective Separation (CDS) device was made in the laboratory. Particle size distributions were obtained for roadway drainage surfaces. These distributions were used to assess the predicted performance of a CDS unit in the field. Flow rates in the laboratory tests ranged from 125 GPM (7.9 l/s) to 270 GPM (17.0 l/s). Screen sizes used for testing were 1200 m and 2400 m. Using four different sand types and the two screen sizes, particle capture rates were determined for the CDS unit. Internal velocities were measured at seventy-two measuring positions within the main chamber of the CDS unit. At 270 GPM capture rates based on particle size ranged from 12% to 100% with the 2400 m screen, and 22% to 100% with the 1200 m screen. Cumulative mass capture rates were 73% and 70% for the 1200 m and 2400 m screens, respectively, at 270 gpm and 84% at 125 gpm for the given particle distribution used. Title: Continuous Deflection Separation of Stormwater Particulates Author: Schwarz, Tracy S., Wells, Scott A. Year: 1999 Capture of stormwater particulate matter is of concern to watershed managers trying to meet water quality guidelines by removing toxics associated with particulates from natural water bodies. A laboratory investigation into particle removal efficiency of a prototype Continuous Deflective Separation (CDS) device was made in the laboratory. Particle size distributions were obtained for roadway drainage surfaces. These distributions were used to assess the predicted performance of a CDS unit in the field. Flow rates in the laboratory tests ranged from 125 GPM (7.9 l/s) to 270 GPM (17.0 l/s). Screen sizes used for testing were 1200 m and 2400 m. Using four different sand types and the two screen sizes, particle capture rates were determined for the CDS unit. Internal velocities were measured at seventy-two measuring positions within the main chamber of the CDS unit. At 270 GPM capture rates based on particle size ranged from 12% to 100% with the 2400 m screen, and 22% to 100% with the 1200 m screen. Cumulative mass capture rates were 73% and 70% for the 1200 m and 2400 m screens, respectively, at 270 gpm and 84% at 125 gpm for the given particle distribution used. Close

• 7. [Article] Modeling Fecal Bacteria in Oregon Coastal Streams Using Spatially Explicit Watershed Characteristics

  Pathogens, such as Escherichia coli and fecal coliforms, are causing the majority of water quality impairments in U.S., making up ~87% of this grouping's violations. Predicting and characterizing source, ...

  Citation × Citation Citation Abstract Copy Title: Modeling Fecal Bacteria in Oregon Coastal Streams Using Spatially Explicit Watershed Characteristics Author: Pettus, Paul Bryce Year: 2013 Pathogens, such as Escherichia coli and fecal coliforms, are causing the majority of water quality impairments in U.S., making up ~87% of this grouping's violations. Predicting and characterizing source, transport processes, and microbial survival rates is extremely challenging, due to the dynamic nature of each of these components. This research built upon current analytical methods that are used as exploratory tools to predict pathogen indicator counts across regional scales. Using a series of non-parametric methodologies, with spatially explicit predictors, 6657 samples from non-estuarine lotic streams were analyzed to make generalized predictions of regional water quality. 532 frequently sampled sites in the Oregon Coast Range Ecoregion, were parsed down to 93 pathogen sampling sites in effect to control for spatial and temporal biases. This generalized model was able to provide credible results in assessing regional water quality, using spatial techniques, and applying them to infrequently or unmonitored catchments. This model's 56.5% explanation of variation, was comparable to other researchers' regional assessments. This research confirmed linkages to land uses related to anthropogenic activities such as animal operations and agriculture, and general riparian conditions. Title: Modeling Fecal Bacteria in Oregon Coastal Streams Using Spatially Explicit Watershed Characteristics Author: Pettus, Paul Bryce Year: 2013 Pathogens, such as Escherichia coli and fecal coliforms, are causing the majority of water quality impairments in U.S., making up ~87% of this grouping's violations. Predicting and characterizing source, transport processes, and microbial survival rates is extremely challenging, due to the dynamic nature of each of these components. This research built upon current analytical methods that are used as exploratory tools to predict pathogen indicator counts across regional scales. Using a series of non-parametric methodologies, with spatially explicit predictors, 6657 samples from non-estuarine lotic streams were analyzed to make generalized predictions of regional water quality. 532 frequently sampled sites in the Oregon Coast Range Ecoregion, were parsed down to 93 pathogen sampling sites in effect to control for spatial and temporal biases. This generalized model was able to provide credible results in assessing regional water quality, using spatial techniques, and applying them to infrequently or unmonitored catchments. This model's 56.5% explanation of variation, was comparable to other researchers' regional assessments. This research confirmed linkages to land uses related to anthropogenic activities such as animal operations and agriculture, and general riparian conditions. Close

• 8. [Article] Investigating the Link Between Surface Water and Groundwater in the Tule Lake Subbasin, Oregon and California

  Water allocation in the upper Klamath Basin of Oregon and California has been challenging. Irrigators have increasingly turned to groundwater to make up for surface water shortages because of shifts in ...

  Citation × Citation Citation Abstract Copy Title: Investigating the Link Between Surface Water and Groundwater in the Tule Lake Subbasin, Oregon and California Author: Pischel, Esther Maria Year: 2014 Water allocation in the upper Klamath Basin of Oregon and California has been challenging. Irrigators have increasingly turned to groundwater to make up for surface water shortages because of shifts in allocation toward in-stream flows for Endangered Species Act listed fishes. The largest increase in groundwater pumping has been in and around the Bureau of Reclamation's Klamath Irrigation Project, which includes the Tule Lake subbasin in the southern part of the upper Klamath Basin. Previous groundwater flow model simulations indicate that water level declines from pumping may result in decreased flow to agricultural drains in the Tule Lake subbasin. Agricultural drains on the Klamath Project are an important source of water for downstream irrigators and for the Tule Lake and Lower Klamath Lake National Wildlife Refuges. To better assess the impact of increased pumping on drain flow and on the water balance of the groundwater system, flow data from agricultural drains were evaluated to investigate the changes that have taken place in groundwater discharge to drains since pumping volumes increased. Additionally, a fine-grid groundwater model of the Tule Lake subbasin was developed based on the existing regional flow model. The fine-grid model has sufficient vertical and horizontal resolution to simulate vertical head gradients, takes advantage of time-series data from 38 observation wells for model calibration, and allows agricultural drains to be more explicitly represented. Results of the drain flow analysis show that the groundwater discharge to agricultural drains has decreased by approximately 4000 hectare-meters from the 1997-2000 average discharge. Most of this decrease takes place in the northern and southeastern portions of the subbasin. Results of the groundwater model show that the initial source of water to wells is groundwater storage. By 2006, approximately 56% of the water from wells is sourced from agricultural drains. Title: Investigating the Link Between Surface Water and Groundwater in the Tule Lake Subbasin, Oregon and California Author: Pischel, Esther Maria Year: 2014 Water allocation in the upper Klamath Basin of Oregon and California has been challenging. Irrigators have increasingly turned to groundwater to make up for surface water shortages because of shifts in allocation toward in-stream flows for Endangered Species Act listed fishes. The largest increase in groundwater pumping has been in and around the Bureau of Reclamation's Klamath Irrigation Project, which includes the Tule Lake subbasin in the southern part of the upper Klamath Basin. Previous groundwater flow model simulations indicate that water level declines from pumping may result in decreased flow to agricultural drains in the Tule Lake subbasin. Agricultural drains on the Klamath Project are an important source of water for downstream irrigators and for the Tule Lake and Lower Klamath Lake National Wildlife Refuges. To better assess the impact of increased pumping on drain flow and on the water balance of the groundwater system, flow data from agricultural drains were evaluated to investigate the changes that have taken place in groundwater discharge to drains since pumping volumes increased. Additionally, a fine-grid groundwater model of the Tule Lake subbasin was developed based on the existing regional flow model. The fine-grid model has sufficient vertical and horizontal resolution to simulate vertical head gradients, takes advantage of time-series data from 38 observation wells for model calibration, and allows agricultural drains to be more explicitly represented. Results of the drain flow analysis show that the groundwater discharge to agricultural drains has decreased by approximately 4000 hectare-meters from the 1997-2000 average discharge. Most of this decrease takes place in the northern and southeastern portions of the subbasin. Results of the groundwater model show that the initial source of water to wells is groundwater storage. By 2006, approximately 56% of the water from wells is sourced from agricultural drains. Close

• 9. [Article] A Performance Assessment of Two Multi-component Water Quality Facilities in the Columbia Slough and Fairview Creek Watersheds

  We examined the treatment trains at the Columbia Slough (CSWQF) and Fairview Creek Water Quality Facilities (FCWQF) in Gresham, OR and assessed their effectiveness at removing pollutants including nutrients, ...

  Citation × Citation Citation Abstract Copy Title: A Performance Assessment of Two Multi-component Water Quality Facilities in the Columbia Slough and Fairview Creek Watersheds Author: Robinson, Christopher Year: 2012 We examined the treatment trains at the Columbia Slough (CSWQF) and Fairview Creek Water Quality Facilities (FCWQF) in Gresham, OR and assessed their effectiveness at removing pollutants including nutrients, TSS, metals, pesticides, PAHs, and VOCs. Time-paced, fixed volume composite samples were collected during storm events at the inlets and outlet of the CSWQF and at the inlets and outlet of each treatment train component of the FCWQF. In addition, long-term data collected at the FCWQF was analyzed. Composite data collected during November 2-3, 2011 and March 5-6, 2012 showed that the treatment trains can measurably reduce the event mean concentration (EMC) of most pollutants present in stormwater. Removal efficiencies ranged from a low of 11 to 34 percent for nutrients to a high of 58 to 70 percent for TSS. Long-term data from the FCWQF confirms the findings of the individual sampling events and demonstrates that the FCWQF treatment train significantly reduces the EMCs of NH3-N, TKN, BOD5, most of the heavy metals tested for, bacteria, TSS, and turbidity. When compared to data available from the International Stormwater BMP Database, effluent concentrations at the FCWQF were comparable to or lower than those in the BMP Database for nutrients including TKN, OP, and TP; metals including DCu, TCu, TNi, DPb, and TPb; and TSS. Effluent concentrations at the FCWQF were higher than those in the BMP Database for DZn, TZn, turbidity, and bacteria. When comparing the two facilities, the FCWQF generally reduced pollutant concentrations to a greater degree than did the CSWQF. Pollutant removal efficiency was potentially limited by rainfall intensity and seasonal factors, with removal efficiencies being higher for the spring event than the fall event. It is recommended that long-term monitoring be continued at both facilities until the pollutant removal efficiency of the entire CSWQF and the FCWQF treatment train components can be statistically quantified. Changes in sample collection methods and flow measurement are recommended that could improve the accuracy of pollutant concentration estimates considerably. Finally, it is recommended that further research be conducted to determine if significant relationships can be established between particle size and the following pollutants: heavy metals, total phosphorus, and PAHs. Defining these relationships may make it possible to estimate pollutant concentrations using the stormwater particle size distribution analysis. Title: A Performance Assessment of Two Multi-component Water Quality Facilities in the Columbia Slough and Fairview Creek Watersheds Author: Robinson, Christopher Year: 2012 We examined the treatment trains at the Columbia Slough (CSWQF) and Fairview Creek Water Quality Facilities (FCWQF) in Gresham, OR and assessed their effectiveness at removing pollutants including nutrients, TSS, metals, pesticides, PAHs, and VOCs. Time-paced, fixed volume composite samples were collected during storm events at the inlets and outlet of the CSWQF and at the inlets and outlet of each treatment train component of the FCWQF. In addition, long-term data collected at the FCWQF was analyzed. Composite data collected during November 2-3, 2011 and March 5-6, 2012 showed that the treatment trains can measurably reduce the event mean concentration (EMC) of most pollutants present in stormwater. Removal efficiencies ranged from a low of 11 to 34 percent for nutrients to a high of 58 to 70 percent for TSS. Long-term data from the FCWQF confirms the findings of the individual sampling events and demonstrates that the FCWQF treatment train significantly reduces the EMCs of NH3-N, TKN, BOD5, most of the heavy metals tested for, bacteria, TSS, and turbidity. When compared to data available from the International Stormwater BMP Database, effluent concentrations at the FCWQF were comparable to or lower than those in the BMP Database for nutrients including TKN, OP, and TP; metals including DCu, TCu, TNi, DPb, and TPb; and TSS. Effluent concentrations at the FCWQF were higher than those in the BMP Database for DZn, TZn, turbidity, and bacteria. When comparing the two facilities, the FCWQF generally reduced pollutant concentrations to a greater degree than did the CSWQF. Pollutant removal efficiency was potentially limited by rainfall intensity and seasonal factors, with removal efficiencies being higher for the spring event than the fall event. It is recommended that long-term monitoring be continued at both facilities until the pollutant removal efficiency of the entire CSWQF and the FCWQF treatment train components can be statistically quantified. Changes in sample collection methods and flow measurement are recommended that could improve the accuracy of pollutant concentration estimates considerably. Finally, it is recommended that further research be conducted to determine if significant relationships can be established between particle size and the following pollutants: heavy metals, total phosphorus, and PAHs. Defining these relationships may make it possible to estimate pollutant concentrations using the stormwater particle size distribution analysis. Close

• 10. [Article] Effects of HRU Size on PRMS Performance in 30 Western U.S. Basins

  Semi-distributed hydrological models are often used for streamflow forecasting, hydrological climate change impact assessments, and other applications. In such models, basins are broken up into hydrologic ...

  Citation × Citation Citation Abstract Copy Title: Effects of HRU Size on PRMS Performance in 30 Western U.S. Basins Author: Steele, Madeline Olena Year: 2013 Semi-distributed hydrological models are often used for streamflow forecasting, hydrological climate change impact assessments, and other applications. In such models, basins are broken up into hydrologic response units (HRUs), which are assumed to have a relatively homogenous response to precipitation. HRUs are delineated in a variety of ways, and the procedure used may impact model performance. HRU delineation procedures have been researched, but it is still not clear how important these subdivision schemes are or which delineation methods are most effective. To start addressing this knowledge gap, this project investigated whether or not HRU size has a significant effect on streamflow simulation at the mouth of a watershed. To test this, 30 gaged, relatively unimpaired western U.S. basins were each modeled with 6 HRU sets of different sizes using the Precipitation Runoff Modeling System (PRMS). To isolate size as a variable, HRUs were delineated using stream catchments. For each basin, streams were defined with 6 different threshold levels, producing HRUs of differing sizes. Nineteen model parameters were derived for each HRU using nationally consistent GIS datasets, and all other model parameters were left at default values. Climate inputs were derived from a national 4-km2 gridded daily climate dataset. After calibration, 4 goodness-of-fit metrics were calculated for daily streamflow for each HRU set. Uncalibrated model performance was generally poor for a variety of reasons, but comparison of the models was still informative. Results for the 30 basins across the 6 HRU size classes showed that HRU size did not significantly impact model performance across all basins. However, in basins that had less total precipitation and higher elevation, sensitivity of model performance to HRU subdivision levels was slightly greater, though not significantly so. Findings indicate that, in most basins, little subdivision may be required for good model performance, allowing for desirable simplicity and fewer degrees of freedom without sacrificing runoff simulation accuracy. Title: Effects of HRU Size on PRMS Performance in 30 Western U.S. Basins Author: Steele, Madeline Olena Year: 2013 Semi-distributed hydrological models are often used for streamflow forecasting, hydrological climate change impact assessments, and other applications. In such models, basins are broken up into hydrologic response units (HRUs), which are assumed to have a relatively homogenous response to precipitation. HRUs are delineated in a variety of ways, and the procedure used may impact model performance. HRU delineation procedures have been researched, but it is still not clear how important these subdivision schemes are or which delineation methods are most effective. To start addressing this knowledge gap, this project investigated whether or not HRU size has a significant effect on streamflow simulation at the mouth of a watershed. To test this, 30 gaged, relatively unimpaired western U.S. basins were each modeled with 6 HRU sets of different sizes using the Precipitation Runoff Modeling System (PRMS). To isolate size as a variable, HRUs were delineated using stream catchments. For each basin, streams were defined with 6 different threshold levels, producing HRUs of differing sizes. Nineteen model parameters were derived for each HRU using nationally consistent GIS datasets, and all other model parameters were left at default values. Climate inputs were derived from a national 4-km2 gridded daily climate dataset. After calibration, 4 goodness-of-fit metrics were calculated for daily streamflow for each HRU set. Uncalibrated model performance was generally poor for a variety of reasons, but comparison of the models was still informative. Results for the 30 basins across the 6 HRU size classes showed that HRU size did not significantly impact model performance across all basins. However, in basins that had less total precipitation and higher elevation, sensitivity of model performance to HRU subdivision levels was slightly greater, though not significantly so. Findings indicate that, in most basins, little subdivision may be required for good model performance, allowing for desirable simplicity and fewer degrees of freedom without sacrificing runoff simulation accuracy. Close