Limiting Factors



Lower Columbia Province

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.