Limiting Factors



Lower Columbia Province

Columbia Lower Subbasin 370, 362

CHUM
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Impervious Surfaces Fry Dike construction and urban and agricultural development have caused extensive losses of habitat connectivity.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management; Agricultural Practices; Urbanization Water: Hydrologic Cycle Alteration; Diking; Filling; Impervious Surfaces Fry Water regulation and urban and agricultural development have caused extensive losses of shallow, low velocity habitat used by juvenile salmonids.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Industrial Chemicals Juveniles Contaminants accumulate in the mainstem and estuary.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration Juveniles; adult spawners Water regulation at Bonneville Dam affects water level in mainstem spawning locations. Water regulation also delays downstream migration of juvenile salmonids.
COHO
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Biological Viability Criteria Diversity -- Artificial Propogation Straying Adult spawners Large numbers of stray coho spawning with indigenous populations pose serious genetic risks.
Food Altered Primary Productivity -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration; Water: Nutrient Alteration Juveniles Hydrosystem operations affect the hydrograph and nutrient input into the estuary.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Impervious Surfaces Juveniles Dike construction and urban and agricultural development have caused extensive losses of habitat connectivity.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management; Agricultural Practices; Urbanization Water: Hydrologic Cycle Alteration; Diking; Filling; Impervious Surfaces Juveniles Water regulation and urban and agricultural development have caused extensive losses of shallow, low velocity habitat used by juvenile salmonids.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Industrial Chemicals Juveniles Contaminants accumulate in the mainstem and estuary.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration Juveniles; adult spawners Water regulation at Bonneville Dam affects water level in mainstem spawning locations. Water regulation also delays downstream migration of juvenile salmonids.
FALL CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Biological Viability Criteria Diversity -- Artificial Propogation Straying Adult spawners Large numbers of stray fall Chinook spawning with indigenous populations pose serious genetic risks.
Food Altered Primary Productivity -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration; Water: Nutrient Alteration Juveniles Hydrosystem operations affect the hydrograph and nutrient input into the estuary.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Impervious Surfaces Juveniles Dike construction and urban and agricultural development have caused extensive losses of habitat connectivity.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management; Agricultural Practices; Urbanization Water: Hydrologic Cycle Alteration; Diking; Filling; Impervious Surfaces Fry Water regulation and urban and agricultural development have caused extensive losses of shallow, low velocity habitat used by juvenile salmonids.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Fall Chinook are subject to both ocean and freshwater harvest.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Industrial Chemicals Juveniles Contaminants accumulate in the mainstem and estuary.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration Juveniles; adult spawners Water regulation at Bonneville Dam affects water level in mainstem spawning locations. Water regulation also delays downstream migration of juvenile salmonids.
GREEN STURGEON
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Adults Historical complex habitats have been modified through channelization, diking, development and other practices.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Industrial Chemicals Adults Contaminants accumulate in the mainstem and estuary.
PACIFIC LAMPREY
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Altered Primary Productivity -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration; Water: Nutrient Alteration Juveniles; adults Hydrosystem operations affect the hydrograph and nutrient input into the estuary.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Impervious Surfaces Juveniles Dike construction and urban and agricultural development have caused extensive losses of habitat connectivity.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Industrial Chemicals Juveniles Contaminants accumulate in the mainstem and estuary.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration Juveniles Water regulation delays downstream migration of juvenile Pacific lamprey.
SPRING CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Altered Primary Productivity -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration; Water: Nutrient Alteration Juveniles Hydrosystem operations affect the hydrograph and nutrient input into the estuary.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Industrial Chemicals Juveniles Contaminants accumulate in the mainstem and estuary.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration Juveniles Water regulation at Bonneville Dam affects water level in mainstem spawning locations. Water regulation also delays downstream migration of juvenile salmonids.
SUMMER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Altered Primary Productivity -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration; Water: Nutrient Alteration Juveniles Hydrosystem operations affect the hydrograph and nutrient input into the estuary.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Impervious Surfaces Juveniles Dike construction and urban and agricultural development have caused extensive losses of habitat connectivity.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management; Agricultural Practices; Urbanization Water: Hydrologic Cycle Alteration; Diking; Filling; Impervious Surfaces Juveniles Water regulation and urban and agricultural development have caused extensive losses of shallow, low velocity habitat used by juvenile salmonids.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Industrial Chemicals Juveniles Contaminants accumulate in the mainstem and estuary.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration Juveniles Water regulation at Bonneville Dam affects water level in mainstem spawning locations. Water regulation also delays downstream migration of juvenile salmonids.
WHITE STURGEON
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration Juveniles, adults Hydrosystem operations affect the hydrograph and spawning of white sturgeon.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles, adults Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Impervious Surfaces Juveniles Dike construction and urban and agricultural development have caused extensive losses of habitat connectivity.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Harvest of white sturgeon must be closely monitored and regulated.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Industrial Chemicals All Contaminants accumulate in the mainstem and estuary.
WINTER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Altered Primary Productivity -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration; Water: Nutrient Alteration Juveniles Hydrosystem operations affect the hydrograph and nutrient input into the estuary.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Impervious Surfaces Juveniles Dike construction and urban and agricultural development have caused extensive losses of habitat connectivity.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management; Agricultural Practices; Urbanization Water: Hydrologic Cycle Alteration; Diking; Filling; Impervious Surfaces Juveniles Water regulation and urban and agricultural development have caused extensive losses of shallow, low velocity habitat used by juvenile salmonids.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Industrial Chemicals Juveniles Contaminants accumulate in the mainstem and estuary.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration Juveniles Water regulation at Bonneville Dam affects water level in mainstem spawning locations. Water regulation also delays downstream migration of juvenile salmonids.

Cowlitz Subbasin 362

CHUM
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Biological Viability Criteria Diversity -- Artificial Propogation Straying Adult spawners Large numbers of stray chum spawning with indigenous populations pose serious genetic risks.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking Fry Extensive diking has disconnected the floodplain.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Forest Management; Urbanization Diking; Filling; Riparian Degradation Adults Riparian areas are severely degraded in the lower 20 miles of the Cowlitz. Buffers are inadequate between river miles 20 and 52. Channel stability is a problem in the North Fork Tilton and Upper Cowlitz. In the Coweeman, land use has resulted in poor bank stability from river miles 4 to 7.5, and 17 to 26.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Diking; Filling; Impervious Surfaces; Riparian Degradation Eggs, adults Most side-channel habitat has been eliminated from the Lower Cowlitz. Large woody debris levels are low throughout the subbasin.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Eggs, adults Pathogens from hatcheries may limit productivity.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Mass Wasting;Erosion Control, Flood Prevention & Over-water Structures; Urbanization Landslides; Impervious Surfaces (Road Density); Beach Alteration; Sediment: Bank Destabilization Eggs, adults Most streams are sediment impaired. The Cispus River (Upper Cowlitz watershed) experiences excessive sedimentation due to mass wasting and roads. A sediment retention structure in the North Fork Toutle River is a major source of sedimentation.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration Eggs, adults The Lower Cowlitz is on the Washington state 303(d) list for exceeding pH, temperature, and fecal coliform standards. Silver and Willame creeks (Upper Cowlitz watershed), Green River and Harrington Creek (Toutle watershed), and the Lower Coweeman River are 303(d) listed for temperature.
Water Quantity Decreased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Water: Storage or Withdrawal, Channelization, Management Eggs, adults Low flows limit adult holding and spawning, and egg survival.
COASTAL CUTTHROAT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking Juveniles Extensive diking has disconnected the floodplain.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Forest Management; Urbanization Diking; Filling; Riparian Degradation Juveniles, adults Riparian areas are severely degraded in the lower 20 miles of the Cowlitz. Buffers are inadequate between river miles 20 and 52. Channel stability is a problem in the North Fork Tilton and Upper Cowlitz. In the Coweeman, land use has resulted in poor bank stability from river miles 4 to 7.5, and 17 to 26.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Diking; Filling; Impervious Surfaces; Riparian Degradation Juveniles, adults Most side-channel habitat has been eliminated from the Lower Cowlitz. Large woody debris levels are low throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Mass Wasting;Erosion Control, Flood Prevention & Over-water Structures; Urbanization Landslides; Impervious Surfaces (Road Density); Beach Alteration; Sediment: Bank Destabilization All Most streams are sediment impaired. The Cispus River (Upper Cowlitz watershed) experiences excessive sedimentation due to mass wasting and roads. A sediment retention structure in the North Fork Toutle River is a major source of sedimentation.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The Lower Cowlitz is on the Washington state 303(d) list for exceeding pH, temperature, and fecal coliform standards. Silver and Willame creeks (Upper Cowlitz watershed), Green River and Harrington Creek (Toutle watershed), and the Lower Coweeman River are 303(d) listed for temperature.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Water: Storage or Withdrawal, Channelization, Management Juveniles, adults Most streams in the Upper Cowlitz watershed experience increased peak flows. Low summer flows in Outlet Creek (Toutle watershed) limit juvenile fish rearing.
COHO
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Diking; Filling; Impervious Surfaces; Riparian Degradation Juveniles, adults Most side-channel habitat has been eliminated from the Lower Cowlitz. Large woody debris levels are low throughout the subbasin.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Forest Management; Urbanization Diking; Filling; Riparian Degradation Juveniles, adults Riparian areas are severely degraded in the lower 20 miles of the Cowlitz. Buffers are inadequate between river miles 20 and 52. Channel stability is a problem in the North Fork Tilton and Upper Cowlitz. In the Coweeman, land use has resulted in poor bank stability from river miles 4 to 7.5, and 17 to 26.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Coho are subject to both ocean and freshwater harvest.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Summer parr Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Mass Wasting;Erosion Control, Flood Prevention & Over-water Structures; Urbanization Landslides; Impervious Surfaces (Road Density); Beach Alteration; Sediment: Bank Destabilization All Most streams are sediment impaired. The Cispus River (Upper Cowlitz watershed) experiences excessive sedimentation due to mass wasting and roads. A sediment retention structure in the North Fork Toutle River is a major source of sedimentation.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The Lower Cowlitz is on the Washington state 303(d) list for exceeding pH, temperature, and fecal coliform standards. Silver and Willame creeks (Upper Cowlitz watershed), Green River and Harrington Creek (Toutle watershed), and the Lower Coweeman River are 303(d) listed for temperature.
Water Quantity Decreased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Water: Storage or Withdrawal, Channelization, Management Juveniles Low flows impede Chinook and coho salmon in the Coweeman River.
FALL CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking Fry Extensive diking has disconnected the floodplain.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Forest Management; Urbanization Diking; Filling; Riparian Degradation Juveniles, adults Riparian areas are severely degraded in the lower 20 miles of the Cowlitz. Buffers are inadequate between river miles 20 and 52. Channel stability is a problem in the North Fork Tilton and Upper Cowlitz. In the Coweeman, land use has resulted in poor bank stability from river miles 4 to 7.5, and 17 to 26.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Diking; Filling; Impervious Surfaces; Riparian Degradation All Most side-channel habitat has been eliminated from the Lower Cowlitz. Large woody debris levels are low throughout the subbasin.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Fall Chinook are subject to both ocean and freshwater harvest.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Eggs, adults Pathogens from hatcheries may limit productivity.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Summer parr Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Mass Wasting;Erosion Control, Flood Prevention & Over-water Structures; Urbanization Landslides; Impervious Surfaces (Road Density); Beach Alteration; Sediment: Bank Destabilization All Most streams are sediment impaired. The Cispus River (Upper Cowlitz watershed) experiences excessive sedimentation due to mass wasting and roads. A sediment retention structure in the North Fork Toutle River is a major source of sedimentation.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The Lower Cowlitz is on the Washington state 303(d) list for exceeding pH, temperature, and fecal coliform standards. Silver and Willame creeks (Upper Cowlitz watershed), Green River and Harrington Creek (Toutle watershed), and the Lower Coweeman River are 303(d) listed for temperature.
Water Quantity Decreased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Water: Storage or Withdrawal, Channelization, Management Juveniles Low flows impede Chinook and coho salmon in the Coweeman River.
SPRING CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking Juveniles, adults Extensive diking has disconnected the floodplain.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Forest Management; Urbanization Diking; Filling; Riparian Degradation Juveniles, adults Riparian areas are severely degraded in the lower 20 miles of the Cowlitz. Buffers are inadequate between river miles 20 and 52. Channel stability is a problem in the North Fork Tilton and Upper Cowlitz. In the Coweeman, land use has resulted in poor bank stability from river miles 4 to 7.5, and 17 to 26.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Diking; Filling; Impervious Surfaces; Riparian Degradation All Most side-channel habitat has been eliminated from the Lower Cowlitz. Large woody debris levels are low throughout the subbasin.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Eggs, adults Pathogens from hatcheries may limit productivity.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Mass Wasting;Erosion Control, Flood Prevention & Over-water Structures; Urbanization Landslides; Impervious Surfaces (Road Density); Beach Alteration; Sediment: Bank Destabilization All Most streams are sediment impaired. The Cispus River (Upper Cowlitz watershed) experiences excessive sedimentation due to mass wasting and roads. A sediment retention structure in the North Fork Toutle River is a major source of sedimentation.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The Lower Cowlitz is on the Washington state 303(d) list for exceeding pH, temperature, and fecal coliform standards. Silver and Willame creeks (Upper Cowlitz watershed), Green River and Harrington Creek (Toutle watershed), and the Lower Coweeman River are 303(d) listed for temperature.
Water Quantity Decreased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Water: Storage or Withdrawal, Channelization, Management All Most streams in the Upper Cowlitz watershed experience increased peak flows. Low summer flows in Outlet Creek (Toutle watershed) limit juvenile fish rearing. Low flows impede Chinook and coho salmon in the Coweeman River.
WINTER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking Juveniles, adults Extensive diking has disconnected the floodplain.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Forest Management; Urbanization Diking; Filling; Riparian Degradation Juveniles, adults Riparian areas are severely degraded in the lower 20 miles of the Cowlitz. Buffers are inadequate between river miles 20 and 52. Channel stability is a problem in the North Fork Tilton and Upper Cowlitz. In the Coweeman, land use has resulted in poor bank stability from river miles 4 to 7.5, and 17 to 26.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Diking; Filling; Impervious Surfaces; Riparian Degradation All Most side-channel habitat has been eliminated from the Lower Cowlitz. Large woody debris levels are low throughout the subbasin.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Summer parr Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Mass Wasting;Erosion Control, Flood Prevention & Over-water Structures; Urbanization Landslides; Impervious Surfaces (Road Density); Beach Alteration; Sediment: Bank Destabilization All Most streams are sediment impaired. The Cispus River (Upper Cowlitz watershed) experiences excessive sedimentation due to mass wasting and roads. A sediment retention structure in the North Fork Toutle River is a major source of sedimentation.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The Lower Cowlitz is on the Washington state 303(d) list for exceeding pH, temperature, and fecal coliform standards. Silver and Willame creeks (Upper Cowlitz watershed), Green River and Harrington Creek (Toutle watershed), and the Lower Coweeman River are 303(d) listed for temperature.
Water Quantity Decreased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Water: Storage or Withdrawal, Channelization, Management All Most streams in the Upper Cowlitz watershed experience increased peak flows. Low summer flows in Outlet Creek (Toutle watershed) limit juvenile fish rearing.

Kalama Subbasin 362

CHUM
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Fry Forest practices and high road densities have resulted in diminished floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management Riparian Degradation Fry, adults Riparian vegetation is lacking throughout the subbasin due to forest practices of the 1960’s through 1980’s.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Riparian Degradation; Wood/Structure Removal Fry, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Adults Pathogens from hatcheries may limit productivity.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Sediment: Upland Disturbance All Excessive sedimentation related to past forest practices and high road density is a problem throughout the subbasin.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The lower 10 miles of the Kalama River and Fallert Creek are on the Washington state 303(d) list for exceeding temperature standards. Temperature is especially a problem at the mouth, where sediments have created a wide, shallow channel.
Water Quantity Altered Flow Timing -- Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Variation All Past forest practices and high road densities have altered flow patterns throughout the subbasin.
COASTAL CUTTHROAT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Juveniles, adults Forest practices and high road densities have resulted in diminished floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management Riparian Degradation Juveniles, adults Riparian vegetation is lacking throughout the subbasin due to forest practices of the 1960’s through 1980’s.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Sediment: Upland Disturbance All Excessive sedimentation related to past forest practices and high road density is a problem throughout the subbasin.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The lower 10 miles of the Kalama River and Fallert Creek are on the Washington state 303(d) list for exceeding temperature standards. Temperature is especially a problem at the mouth, where sediments have created a wide, shallow channel.
Water Quantity Altered Flow Timing -- Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Variation All Past forest practices and high road densities have altered flow patterns throughout the subbasin.
COHO
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Juveniles Forest practices and high road densities have resulted in diminished floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management Riparian Degradation Juveniles, adults Riparian vegetation is lacking throughout the subbasin due to forest practices of the 1960’s through 1980’s.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Coho are subject to both ocean and freshwater harvest.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Summer parr Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Sediment: Upland Disturbance All Excessive sedimentation related to past forest practices and high road density is a problem throughout the subbasin.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration Eggs, summer parr The lower 10 miles of the Kalama River and Fallert Creek are on the Washington state 303(d) list for exceeding temperature standards. Temperature is especially a problem at the mouth, where sediments have created a wide, shallow channel.
Water Quantity Altered Flow Timing -- Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Variation Eggs, winter parr Past forest practices and high road densities have altered flow patterns throughout the subbasin.
FALL CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Juveniles Forest practices and high road densities have resulted in diminished floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management Riparian Degradation Juveniles, adults Riparian vegetation is lacking throughout the subbasin due to forest practices of the 1960’s through 1980’s.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Fall Chinook are subject to both ocean and freshwater harvest.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Summer parr Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Sediment: Upland Disturbance All Excessive sedimentation related to past forest practices and high road density is a problem throughout the subbasin.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration Eggs, summer parr The lower 10 miles of the Kalama River and Fallert Creek are on the Washington state 303(d) list for exceeding temperature standards. Temperature is especially a problem at the mouth, where sediments have created a wide, shallow channel.
Water Quantity Altered Flow Timing -- Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Variation Eggs, winter parr Past forest practices and high road densities have altered flow patterns throughout the subbasin.
SPRING CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Juveniles Forest practices and high road densities have resulted in diminished floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management Riparian Degradation Juveniles Riparian vegetation is lacking throughout the subbasin due to forest practices of the 1960’s through 1980’s.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Sediment: Upland Disturbance All Excessive sedimentation related to past forest practices and high road density is a problem throughout the subbasin.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The lower 10 miles of the Kalama River and Fallert Creek are on the Washington state 303(d) list for exceeding temperature standards. Temperature is especially a problem at the mouth, where sediments have created a wide, shallow channel.
Water Quantity Altered Flow Timing -- Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Variation Juveniles Past forest practices and high road densities have altered flow patterns throughout the subbasin.
SUMMER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Juveniles Forest practices and high road densities have resulted in diminished floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management Riparian Degradation Juveniles Riparian vegetation is lacking throughout the subbasin due to forest practices of the 1960’s through 1980’s.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Sediment: Upland Disturbance All Excessive sedimentation related to past forest practices and high road density is a problem throughout the subbasin.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The lower 10 miles of the Kalama River and Fallert Creek are on the Washington state 303(d) list for exceeding temperature standards. Temperature is especially a problem at the mouth, where sediments have created a wide, shallow channel.
Water Quantity Altered Flow Timing -- Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Variation Juveniles Past forest practices and high road densities have altered flow patterns throughout the subbasin.
WINTER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Juveniles Forest practices and high road densities have resulted in diminished floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management Riparian Degradation Juveniles Riparian vegetation is lacking throughout the subbasin due to forest practices of the 1960’s through 1980’s.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Eggs, summer parr Pathogens from hatcheries may limit productivity.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Summer parr Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Sediment: Upland Disturbance All Excessive sedimentation related to past forest practices and high road density is a problem throughout the subbasin.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration All The lower 10 miles of the Kalama River and Fallert Creek are on the Washington state 303(d) list for exceeding temperature standards. Temperature is especially a problem at the mouth, where sediments have created a wide, shallow channel.
Water Quantity Altered Flow Timing -- Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Variation Juveniles Past forest practices and high road densities have altered flow patterns throughout the subbasin.

Lewis Subbasin 362, 371

BULL TROUT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Juveniles, adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Juveniles, adults Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization All Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
CHUM
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Adults Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs, adults Impacts due to sediment occur throughout the subbasin.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration All Altered flows from hydro operations impact egg survival.
COASTAL CUTTHROAT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Juveniles, adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Juveniles, adults Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Juveniles, adults Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization All Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Forest Management Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration Juveniles, adults Flow alterations are related to forest condition and roads in the upper reaches of the East Fork watershed.
COHO
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Fry, summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Juveniles Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Fry, summer parr Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Fry, summer parr Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Coho are subject to both ocean and freshwater harvest.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Fry, summer parr Pathogens from hatcheries may limit productivity.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Summer parr Impacts due to sediment occur throughout the subbasin.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration All Altered flows from hydro operations impact egg survival.
FALL CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Fry Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Fry, adults Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Fry, adults Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Fry, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Fall Chinook are subject to both ocean and freshwater harvest.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs, fry, adults Impacts due to sediment occur throughout the subbasin.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration All Altered flows from hydro operations impact egg survival.
SPRING CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Fry, adults Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Fry, summer parr Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Fry, summer parr Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry, summer parr Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs, fry, summer parr Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Forest Management; Dam or Hydropower Facility Management Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles, adults Flow alterations are related to forest condition and roads in the upper reaches of the East Fork watershed. Hydropower actions alter flow regimes and impair spawning and rearing in the Lower North Fork watershed.
SUMMER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Juveniles Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Juveniles Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Forest Management; Dam or Hydropower Facility Management Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles, adults Flow alterations are related to forest condition and roads in the upper reaches of the East Fork watershed. Hydropower actions alter flow regimes and impair spawning and rearing in the Lower North Fork watershed.
WINTER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Fry, summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Juveniles Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Juveniles Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Fry, summer parr Pathogens from hatcheries may limit productivity.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Forest Management; Dam or Hydropower Facility Management Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles, adults Flow alterations are related to forest condition and roads in the upper reaches of the East Fork watershed. Hydropower actions alter flow regimes and impair spawning and rearing in the Lower North Fork watershed.

Sandy Subbasin 372

COHO
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Channel straightening, ditching, and diking have reduced floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian Degradation; Impervious Surfaces Juveniles The riparian habitat in some of the lower reaches in the basin has been affected by recreation, residential, agricultural, and municipal activities. Agricultural and residential development activities have altered or disturbed some riparian habitat areas.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Riparian Degradation; Wood/Structure Removal Juveniles Many stream reaches surveyed within the Sandy watershed are considered to be moderate to undesirable for attributes such as large wood density and pool frequency.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Coho are subject to both ocean and freshwater harvest.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Bank Destabilization; Impervious Surfaces (Road Density); Riparian Degradation Juveniles While there is a high natural background level of fine sediment in the Sandy River, management practices on both private and federal lands increase fine sediment routing.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration Juveniles Water temperatures in some reaches of the Sandy River Basin exceed state temperature water quality standards
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles Hydrosystem operations affect the hydrograph and nutrient input into the estuary.
FALL CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Channel straightening, ditching, and diking have reduced floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian Degradation; Impervious Surfaces Juveniles The riparian habitat in some of the lower reaches in the basin has been affected by recreation, residential, agricultural, and municipal activities. Agricultural and residential development activities have altered or disturbed some riparian habitat areas.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Riparian Degradation; Wood/Structure Removal Juveniles Many stream reaches surveyed within the Sandy watershed are considered to be moderate to undesirable for attributes such as large wood density and pool frequency.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Fall Chinook are subject to both ocean and freshwater harvest.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Bank Destabilization; Impervious Surfaces (Road Density); Riparian Degradation Juveniles While there is a high natural background level of fine sediment in the Sandy River, management practices on both private and federal lands increase fine sediment routing.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration Juveniles Water temperatures in some reaches of the Sandy River Basin exceed state temperature water quality standards
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles Hydrosystem operations affect the hydrograph and nutrient input into the estuary.
SPRING CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Channel straightening, ditching, and diking have reduced floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian Degradation; Impervious Surfaces Juveniles The riparian habitat in some of the lower reaches in the basin has been affected by recreation, residential, agricultural, and municipal activities. Agricultural and residential development activities have altered or disturbed some riparian habitat areas.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management; Agricultural Practices; Forest Management Sediment: Retention; Riparian Degradation; Wood/Structure Removal Juveniles, adults Lack of suitable spawning gravel in the lower Bull Run River is limiting production of Chinook. Many stream reaches surveyed within the Sandy watershed are considered to be moderate to undesirable for attributes such as large wood density and pool frequency.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Bank Destabilization; Impervious Surfaces (Road Density); Riparian Degradation Juveniles While there is a high natural background level of fine sediment in the Sandy River, management practices on both private and federal lands increase fine sediment routing.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration Juveniles Water temperatures in some reaches of the Sandy River Basin exceed state temperature water quality standards
Water Quantity Decreased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles Fish may be trapped in isolated in the Bull Run River when flows decrease as a result of water storage in upstream reservoirs, and may be subject to high mortality due to predation, and increased temperatures and poor water quality. Hydrosystem operations affect the hydrograph and nutrient input into the estuary.
WINTER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Forest Management; Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Channel straightening, ditching, and diking have reduced floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian Degradation; Impervious Surfaces Juveniles The riparian habitat in some of the lower reaches in the basin has been affected by recreation, residential, agricultural, and municipal activities. Agricultural and residential development activities have altered or disturbed some riparian habitat areas.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management; Agricultural Practices; Forest Management Sediment: Retention; Riparian Degradation; Wood/Structure Removal Juveniles, adults Lack of suitable spawning gravel in the lower Bull Run River is limiting production of Chinook. Many stream reaches surveyed within the Sandy watershed are considered to be moderate to undesirable for attributes such as large wood density and pool frequency.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Bank Destabilization; Impervious Surfaces (Road Density); Riparian Degradation Juveniles While there is a high natural background level of fine sediment in the Sandy River, management practices on both private and federal lands increase fine sediment routing.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration Juveniles Water temperatures in some reaches of the Sandy River Basin exceed state temperature water quality standards
Water Quantity Decreased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles Fish may be trapped in isolated in the Bull Run River when flows decrease as a result of water storage in upstream reservoirs, and may be subject to high mortality due to predation, and increased temperatures and poor water quality. Hydrosystem operations affect the hydrograph and nutrient input into the estuary.

Washougal Subbasin 362

CHUM
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal Adults Channel stability is limiting in the lower reaches of the subbasin. Habitat diversity is diminished primarily by lack of large woody debris in the lower mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian degradation; Impervious Surfaces Adults Many riparian areas are denuded in the Lower Mainstem and Lower Little Washougal watersheds.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Sediment: Upland Disturbances; Impervious Surfaces (Road Density); Riparian Degradation Eggs Sedimentation from upper subbasin sources impacts most of the mainstem.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration; Riparian Degradation Eggs Lacamas Creek and several tributaries were listed on the 1998 state 303(d) list for exceeding dissolved oxygen and temperature standards. Denuded riparian areas in lower reaches and lack of mature forest cover in upper reaches contribute to high temperatures.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water Storage or Withdrawal, Channelization, Management Juveniles, adults Altered flow regimes are caused by high road density in the upper mainstem and West Fork watersheds. Water withdrawals from Jones and Boulder creeks increase the risk of critically low summer flows in the Little Washougal watershed.
COASTAL CUTTHROAT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal Juveniles, adults Channel stability is limiting in the lower reaches of the subbasin. Habitat diversity is diminished primarily by lack of large woody debris in the lower mainstem and in the West Fork.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian degradation; Impervious Surfaces Juveniles, adults Riparian function is degraded in upper reaches. Many riparian areas are denuded in the Lower Mainstem and Lower Little Washougal watersheds.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Sediment: Upland Disturbances; Impervious Surfaces (Road Density); Riparian Degradation All Sedimentation from upper subbasin sources impacts most of the mainstem.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration; Riparian Degradation All Lacamas Creek and several tributaries were listed on the 1998 state 303(d) list for exceeding dissolved oxygen and temperature standards. Denuded riparian areas in lower reaches and lack of mature forest cover in upper reaches contribute to high temperatures.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water Storage or Withdrawal, Channelization, Management Juveniles, adults Altered flow regimes are caused by high road density in the upper mainstem and West Fork watersheds. Water withdrawals from Jones and Boulder creeks increase the risk of critically low summer flows in the Little Washougal watershed.
COHO
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal Juveniles Channel stability is limiting in the lower reaches of the subbasin. Habitat diversity is diminished primarily by lack of large woody debris in the lower mainstem and in the West Fork.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian degradation; Impervious Surfaces Juveniles Riparian function is degraded in upper reaches. Many riparian areas are denuded in the Lower Mainstem and Lower Little Washougal watersheds.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Coho are subject to both ocean and freshwater harvest.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Summer parr Pathogens from hatcheries may limit productivity.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Juveniles Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Sediment: Upland Disturbances; Impervious Surfaces (Road Density); Riparian Degradation Eggs Sedimentation from upper subbasin sources impacts most of the mainstem.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration; Riparian Degradation Summer parr Lacamas Creek and several tributaries were listed on the 1998 state 303(d) list for exceeding dissolved oxygen and temperature standards. Denuded riparian areas in lower reaches and lack of mature forest cover in upper reaches contribute to high temperatures.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water Storage or Withdrawal, Channelization, Management Summer parr Altered flow regimes are caused by high road density in the upper mainstem and West Fork watersheds. Water withdrawals from Jones and Boulder creeks increase the risk of critically low summer flows in the Little Washougal watershed.
FALL CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Forest Management; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal Fry Channel stability is limiting in the lower reaches of the subbasin. Habitat diversity is diminished primarily by lack of large woody debris in the lower mainstem and in the West Fork.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian degradation; Impervious Surfaces Fry Many riparian areas are denuded in the Lower Mainstem and Lower Little Washougal watersheds.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Fall Chinook are subject to both ocean and freshwater harvest.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Sediment: Upland Disturbances; Impervious Surfaces (Road Density); Riparian Degradation Eggs Sedimentation from upper subbasin sources impacts most of the mainstem.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration; Riparian Degradation Summer parr Lacamas Creek and several tributaries were listed on the 1998 state 303(d) list for exceeding dissolved oxygen and temperature standards. Denuded riparian areas in lower reaches and lack of mature forest cover in upper reaches contribute to high temperatures.
SUMMER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Fry, summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Forest Management; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal Juveniles Channel stability is limiting in the lower reaches of the subbasin. Habitat diversity is diminished primarily by lack of large woody debris in the lower mainstem and in the West Fork.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian Degradation; Impervious Surfaces Juveniles Riparian function is degraded in upper reaches. Many riparian areas are denuded in the Lower Mainstem and Lower Little Washougal watersheds.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Fry, summer parr Pathogens from hatcheries may limit productivity.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry, summer parr Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Sediment: Upland Disturbances; Impervious Surfaces (Road Density); Riparian Degradation Eggs Sedimentation from upper subbasin sources impacts most of the mainstem.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration; Riparian Degradation Fry, summer parr Lacamas Creek and several tributaries were listed on the 1998 state 303(d) list for exceeding dissolved oxygen and temperature standards. Denuded riparian areas in lower reaches and lack of mature forest cover in upper reaches contribute to high temperatures.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water Storage or Withdrawal, Channelization, Management Juveniles Altered flow regimes are caused by high road density in the upper mainstem and West Fork watersheds. Water withdrawals from Jones and Boulder creeks increase the risk of critically low summer flows in the Little Washougal watershed.
WINTER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Fry Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Forest Management; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal Fry Channel stability is limiting in the lower reaches of the subbasin. Habitat diversity is diminished primarily by lack of large woody debris in the lower mainstem and in the West Fork.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Riparian Degradation; Impervious Surfaces Fry Riparian function is degraded in upper reaches. Many riparian areas are denuded in the Lower Mainstem and Lower Little Washougal watersheds.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Eggs, fry Pathogens from hatcheries may limit productivity.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Sediment: Upland Disturbances; Impervious Surfaces (Road Density); Riparian Degradation Eggs Sedimentation from upper subbasin sources impacts most of the mainstem.
Water Quality Temperature -- Agricultural Practices; Forest Management; Urbanization Water: Temperature and Gas Alteration; Riparian Degradation Fry Lacamas Creek and several tributaries were listed on the 1998 state 303(d) list for exceeding dissolved oxygen and temperature standards. Denuded riparian areas in lower reaches and lack of mature forest cover in upper reaches contribute to high temperatures.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Agricultural Practices; Forest Management; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water Storage or Withdrawal, Channelization, Management Eggs, fry Altered flow regimes are caused by high road density in the upper mainstem and West Fork watersheds. Water withdrawals from Jones and Boulder creeks increase the risk of critically low summer flows in the Little Washougal watershed.

Willamette Subbasin 367, 371, 373, 374

BULL TROUT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Fishery Management Species Introduction Juveniles, adults Competition and hybridization with brook trout is a concern.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Juveniles, adults Major barriers to upstream migration include Cougar Dam, Trail Bridge Dam, and Smith Dam in the McKenzie River Watershed. Some culverts have been identified as barriers. Hydro facilities may pose risks to downstream-migrating bull trout.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles, adults Land use practices have led to losses of wetlands and floodplain function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density); Riparian Degradation Juveniles, adults Removal of streamside vegetation and road building in the Clackamas River Watershed have reduced habitat. Invasive plants limit the growth of native vegetation needed for habitat and channel formation processes.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles, adults Limited wood in many watersheds has reduced the frequency and depth of pools, limiting rearing. Channels have been simplified.
Water Quality Temperature -- Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Water: Temperature and Gas Alteration; Riparian Degradation All Stream temperatures in many watersheds exceed criteria for summer maximum for juvenile salmonid rearing.
Water Quantity Decreased Water Quantity -- Agricultural Practicies; Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Storage or Withdrawal, Channelization, Management Juveniles, adults Frequency and magnitude of high flows are not sufficient to create and maintain channel complexity and provide nutrients from floodplain areas. Additional flow reductions are associated with irrigation diversions in many watersheds.
CHUM
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Fry Land use practices have led to losses of wetlands and floodplain function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Diking; Filling; Wood/Structure Removal Fry Reduction of off-channel habitat and limited wood in the Clackamas River Watershed have reduced the frequency and depth of pools, limiting rearing. Hydro operations on the Clacakamas River result impaired gravel recruitment, and channel incision.
Water Quality Temperature -- Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Water: Temperature and Gas Alteration; Riparian Degradation Fry Stream temperatures in many watersheds exceed criteria for summer maximum for juvenile salmonid rearing. Hydro operations on the Clacakamas River result in elevated water temperatures
Water Quantity Decreased Water Quantity -- Agricultural Practicies; Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Storage or Withdrawal, Channelization, Management Fry Frequency and magnitude of high flows are not sufficient to create and maintain channel complexity and provide nutrients from floodplain areas. Additional flow reductions are associated with irrigation diversions in many watersheds.
COASTAL CUTTHROAT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability Freshwater-Instream Forest Management; Urbanization Migration Impediments Juveniles, adults Some culverts may be barriers to migration.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles, adults Land use practices have led to losses of wetlands and floodplain function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density); Riparian Degradation Juveniles, adults Removal of streamside vegetation and road building in the Clackamas River Watershed have reduced habitat. Invasive plants limit the growth of native vegetation needed for habitat and channel formation processes.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles, adults Limited wood in many watersheds has reduced the frequency and depth of pools, limiting rearing. Channels have been simplified.
Water Quality Temperature -- Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Water: Temperature and Gas Alteration; Riparian Degradation All Stream temperatures in many watersheds exceed criteria for summer maximum for juvenile salmonid rearing.
Water Quantity Decreased Water Quantity -- Agricultural Practicies; Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Storage or Withdrawal, Channelization, Management Juveniles, adults Frequency and magnitude of high flows are not sufficient to create and maintain channel complexity and provide nutrients from floodplain areas. Additional flow reductions are associated with irrigation diversions in many watersheds.
COHO
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Biological Viability Criteria Diversity -- Artificial Propogation Straying Adult spawners Large numbers of stray coho spawning with indigenous populations pose serious genetic risks.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Land use practices have led to losses of wetlands and floodplain function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density); Riparian Degradation Juveniles Removal of streamside vegetation and road building in the Clackamas River Watershed have reduced habitat.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Diking; Filling; Wood/Structure Removal Juveniles Reduction of off-channel habitat and limited wood in the Clackamas River Watershed have reduced the frequency and depth of pools, limiting rearing. Hydro operations on the Clacakamas River result impaired gravel recruitment, and channel incision.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Coho are subject to both ocean and freshwater harvest.
Water Quality Temperature -- Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Water: Temperature and Gas Alteration; Riparian Degradation Juveniles Stream temperatures in many watersheds exceed criteria for summer maximum for juvenile salmonid rearing. Hydro operations on the Clacakamas River result in elevated water temperatures
Water Quantity Decreased Water Quantity -- Agricultural Practicies; Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Storage or Withdrawal, Channelization, Management Juveniles Frequency and magnitude of high flows are not sufficient to create and maintain channel complexity and provide nutrients from floodplain areas. Additional flow reductions are associated with irrigation diversions in many watersheds.
FALL CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Biological Viability Criteria Diversity -- Artificial Propogation Straying Adult spawners Large numbers of stray fall Chinook spawning with indigenous populations pose serious genetic risks.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Land use practices have led to losses of wetlands and floodplain function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Diking; Filling; Wood/Structure Removal Juveniles Reduction of off-channel habitat and limited wood in the Clackamas River Watershed have reduced the frequency and depth of pools, limiting rearing. Hydro operations on the Clacakamas River result impaired gravel recruitment, and channel incision.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Fall Chinook are subject to both ocean and freshwater harvest.
Water Quality Temperature -- Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Water: Temperature and Gas Alteration; Riparian Degradation Juveniles Stream temperatures in many watersheds exceed criteria for summer maximum for juvenile salmonid rearing. Hydro operations on the Clacakamas River result in elevated water temperatures
Water Quantity Decreased Water Quantity -- Agricultural Practicies; Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Storage or Withdrawal, Channelization, Management Juveniles Frequency and magnitude of high flows are not sufficient to create and maintain channel complexity and provide nutrients from floodplain areas. Additional flow reductions are associated with irrigation diversions in many watersheds.
OREGON CHUB
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss All Land use practices have led to losses of wetlands and floodplain function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density); Riparian Degradation All Land use practices have resulted in loss of riparian vegetation and off-channel habitats.
Instantaneous Mortality Predation -- Fishery Management Species Introduction All Introduced predaceous fish threaten existing populations of Oregon chub, and inhibit re-colonization of formerly occupied habitat.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Sediment: Upland Disturbances; Impervious Surfaces (Road Density); Riparian Degradation All Logging practices in the Middle Fork Willamette watershed contribute sediment to ponds that contain Oregon chub. Land use practices have resulted in increasing sedimentation.
Water Quantity Altered Flow Timing -- Agricultural Practicies; Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Storage or Withdrawal, Channelization, Management All Altered hydrograph resulting from hydro operations prevents the formation of chub habitat and natural dispersal of the species.
SPRING CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Biological Viability Criteria Diversity -- Artificial Propogation Straying Adult spawners Large numbers of stray spring Chinook spawning with indigenous populations pose serious genetic risks.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management Migration Impediments Adults Dams block access to 80% of the historical spring Chinook salmon habitat in the Middle Fork Willamette watershed. Complete barriers also include Detroit and Big Cliff dams in the North Santiam watershed. Dams in the McKenzie and Clackamas watersheds also restrict access.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Land use practices have led to losses of wetlands and floodplain function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Wetland Loss Juveniles Removal of streamside vegetation and road building in the Clackamas River Watershed have reduced habitat. Losses of wetland, floodplain, and off-channel habitats have reduced the quantity and quality of adult salmonid holding areas in the Molalla and Calapooia watersheds. Invasive plants limit the growth of native vegetation needed for habitat and channel formation processes.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Diking; Filling; Wood/Structure Removal Juveniles Limited wood in many watersheds has reduced the frequency and depth of pools, limiting rearing. Channel complexity has been reduced by reduced peak flows.
Water Quality Temperature -- Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Water: Temperature and Gas Alteration; Riparian Degradation Juveniles Stream temperatures in many watersheds exceed criteria for summer maximum for juvenile salmonid rearing. Hydro operations on the Clacakamas River result in elevated water temperatures
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Storage or Withdrawal, Channelization, Management Juveniles Hydro operations result in elevated flows during spawning and subsequent dewatering of redds. Reduced peak flows reduce channel complexity and diversity, and elevated water temperatures cause premature hatching and emergence.
WINTER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Biological Viability Criteria Diversity -- Artificial Propogation Straying Adult spawners Large numbers of stray steelheadk spawning with indigenous populations pose serious genetic risks.
Food Competition -- Artificial Propogation Intraspecific Interaction Juveniles Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management Migration Impediments Adults Complete barriers include Detroit and Big Cliff dams in the North Santiam watershed. Dams in the McKenzie and Clackamas watersheds also restrict access.
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Juveniles Land use practices have led to losses of wetlands and floodplain function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density); Riparian Degradation; Wetland Loss Juveniles Removal of streamside vegetation and road building in the Clackamas River Watershed have reduced habitat. Losses of wetland, floodplain, and off-channel habitats have reduced the quantity and quality of adult salmonid holding areas in the Molalla and Calapooia watersheds. Invasive plants limit the growth of native vegetation needed for habitat and channel formation processes.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Diking; Filling; Wood/Structure Removal Juveniles Limited wood in many watersheds has reduced the frequency and depth of pools, limiting rearing. Channel complexity has been reduced by reduced peak flows.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Juveniles Non-native species introductions have lead to community shifts and predation issues.
Water Quality Temperature -- Agricultural Practicies; Forest Management; Dam or Hydropower Facility Management Water: Temperature and Gas Alteration; Riparian Degradation Juveniles Stream temperatures in many watersheds exceed criteria for summer maximum for juvenile salmonid rearing. Hydro operations on the Clacakamas River result in elevated water temperatures
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management Water: Runoff Coefficient Alteration; Water: Storage or Withdrawal, Channelization, Management Juveniles Hydro operations result in elevated flows during spawning and subsequent dewatering of redds. Reduced peak flows reduce channel complexity and diversity, and elevated water temperatures cause premature hatching and emergence.