Limiting Factors



Columbia Gorge Province

Hood Subbasin 380, 381, 368

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 Migration Impediments Juveniles, adults Powerdale Dam impedes upstream and downstream migration of all fish. Clear Branch Dam, and the Eliot and Coe diversions block bull trout.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Agricultural Practices Migration Impediments Juveniles Unscreened diversions impact juvenile fish in Neal Creek, Tony Creek, Eliot Branch, and Coe Branch.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices Riparian Degradation; Wood/Structure Removal Juveniles, adults Loss of large woody debris recruitment caused by historic timber practices and clearing of streams has reduced habitat diversity.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management Water: Storage or Withdrawal Juveniles, adults Clear Branch Dam inundated bull trout spawning habitat.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density) All Increased sediment from roads is a major limiting factor for bull trout.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration Juveniles, adults Timber harvest and roads have increased the flashiness of the system.
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 Migration Impediments Juveniles, adults Powerdale Dam impedes upstream and downstream migration of all fish.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Agricultural Practices Migration Impediments Juveniles Unscreened diversions impact juvenile fish in Neal Creek, Tony Creek, Eliot Branch, and Coe Branch.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices Riparian Degradation; Wood/Structure Removal Juveniles, adults Loss of large woody debris recruitment caused by historic timber practices and clearing of streams has reduced habitat diversity.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density) All Increased sediment from roads is a major limiting factor.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration Juveniles, adults Timber harvest and roads have increased the flashiness of the system.
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 out-of-basin stray coho spawning with indigenous populations pose serious genetic risks.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management Migration Impediments Juveniles, adults Powerdale Dam impedes upstream and downstream migration of all fish.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Agricultural Practices Migration Impediments Juveniles Unscreened diversions impact juvenile fish in Neal Creek, Tony Creek, Eliot Branch, and Coe Branch.
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 Riparian Degradation; Wood/Structure Removal; Impervious Surfaces (Road Density) Juveniles Past riparian harvest, transportation networks, and land-use have modified channels and decreased interactions with the floodplain.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices Riparian Degradation; Wood/Structure Removal Juveniles Loss of large woody debris recruitment caused by historic timber practices and clearing of streams has reduced habitat diversity.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management Water: Storage or Withdrawal Juveniles Clear Branch Dam inundated coho spawning habitat.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Coho are subject to both ocean and freshwater harvest.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass Bonneville Dam during migration.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density) Eggs, juveniles Sediment load impacts coho throughout their distribution.
Water Quantity Decreased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management; Agricultural Practices; Water Management Water: Storage or Withdrawal, Channelization, Management; Migration Impediments Juveniles Eighty percent of the flow has been removed in a three-mile reach below Powerdale Dam. Altered flows due to irrigation (Baldwin, Odell, Tieman, and West Fork Neal creeks), hydropower (Powerdale Dam), and municipal water diversions (upper Dog River) limit productivity of anadromous species.
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 out-of-basin stray fall 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 Juveniles, adults Powerdale Dam impedes upstream and downstream migration of all fish.
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 Riparian Degradation; Wood/Structure Removal; Impervious Surfaces (Road Density) Juveniles Past riparian harvest, transportation networks, and land-use have modified channels and decreased interactions with the floodplain.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices Riparian Degradation; Wood/Structure Removal Fry Loss of large woody debris recruitment caused by historic timber practices and clearing of streams has reduced habitat diversity.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Fall Chinook are subject to both ocean and freshwater harvest.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass Bonneville Dam during migration.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density) Eggs, juveniles Sediment load impacts both fall and spring Chinook throughout their distribution.
Water Quantity Decreased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management; Agricultural Practices; Water Management Water: Storage or Withdrawal, Channelization, Management; Migration Impediments Juveniles Eighty percent of the flow has been removed in a three-mile reach below Powerdale Dam. Altered flows due to irrigation (Baldwin, Odell, Tieman, and West Fork Neal creeks), hydropower (Powerdale Dam), and municipal water diversions (upper Dog River) limit productivity of anadromous species.
PACIFIC LAMPREY
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 Migration Impediments Juveniles, adults Powerdale Dam impedes upstream and downstream migration of all fish and may be a barrier to Pacific lamprey.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Agricultural Practices Migration Impediments Juveniles Unscreened diversions impact juvenile fish in Neal Creek, Tony Creek, Eliot Branch, and Coe Branch.
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.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass Bonneville Dam during migration.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density) All Increased sediment from roads is a major limiting factor.
Water Quantity Decreased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management; Agricultural Practices; Water Management Water: Storage or Withdrawal, Channelization, Management; Migration Impediments Juveniles Eighty percent of the flow has been removed in a three-mile reach below Powerdale Dam. Altered flows due to irrigation (Baldwin, Odell, Tieman, and West Fork Neal creeks), hydropower (Powerdale Dam), and municipal water diversions (upper Dog River) limit productivity of anadromous 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 out-of-basin 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 Juveniles, adults Powerdale Dam impedes upstream and downstream migration of all fish.
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.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass Bonneville Dam during migration.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density) Eggs, juveniles Sediment load impacts both fall and spring Chinook throughout their distribution.
Water Quantity Decreased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management; Agricultural Practices; Water Management Water: Storage or Withdrawal, Channelization, Management; Migration Impediments Juveniles Eighty percent of the flow has been removed in a three-mile reach below Powerdale Dam. Altered flows due to irrigation (Baldwin, Odell, Tieman, and West Fork Neal creeks), hydropower (Powerdale Dam), and municipal water diversions (upper Dog River) limit productivity of anadromous species.
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 Migration Impediments Juveniles, adults Powerdale Dam impedes upstream and downstream migration of all fish. Clear Branch and Neal Creek Diversion dams are barriers to steelhead.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Agricultural Practices Migration Impediments Juveniles Unscreened diversions impact juvenile fish in Neal Creek, Tony Creek, Eliot Branch, and Coe Branch.
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 Riparian Degradation; Wood/Structure Removal; Impervious Surfaces (Road Density) Juveniles Past riparian harvest, transportation networks, and land-use have modified channels and decreased interactions with the floodplain.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices Riparian Degradation; Wood/Structure Removal Juveniles Loss of large woody debris recruitment caused by historic timber practices and clearing of streams has reduced habitat diversity.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management Water: Storage or Withdrawal Juveniles Clear Branch Dam inundated steelhead spawning habitat.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass Bonneville Dam during migration.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density) Eggs, juveniles Increased sedimentation from roads and irrigation networks limits egg incubation.
Water Quantity Decreased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management; Agricultural Practices; Water Management Water: Storage or Withdrawal, Channelization, Management; Migration Impediments Juveniles Eighty percent of the flow has been removed in a three-mile reach below Powerdale Dam. Altered flows due to irrigation (Baldwin, Odell, Tieman, and West Fork Neal creeks), hydropower (Powerdale Dam), and municipal water diversions (upper Dog River) limit productivity of anadromous species.
WINTER 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 Migration Impediments Juveniles, adults Powerdale Dam impedes upstream and downstream migration of all fish. Clear Branch and Neal Creek Diversion dams are barriers to steelhead.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Agricultural Practices Migration Impediments Juveniles Unscreened diversions impact juvenile fish in Neal Creek, Tony Creek, Eliot Branch, and Coe Branch.
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 Riparian Degradation; Wood/Structure Removal; Impervious Surfaces (Road Density) Juveniles Past riparian harvest, transportation networks, and land-use have modified channels and decreased interactions with the floodplain.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices Riparian Degradation; Wood/Structure Removal Juveniles Loss of large woody debris recruitment caused by historic timber practices and clearing of streams has reduced habitat diversity.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management Water: Storage or Withdrawal Juveniles Clear Branch Dam inundated steelhead spawning habitat.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass Bonneville Dam during migration.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Agricultural Practices; Urbanization Impervious Surfaces (Road Density) Eggs, juveniles Increased sedimentation from roads and irrigation networks limits winter steelhead egg incubation in Baldwin, Culvert, Evans, and Tieman creeks. Productivity of winter steelhead in Neal and Lenz creeks is limited by pesticides and herbicides.
Toxic Contaminants Water; Biota -- Pollution and Contamination Pollution: Herbicides, Pesticides Pollution Eggs, juveniles Productivity of winter steelhead in Neal and Lenz creeks is limited by pesticides and herbicides.
Water Quantity Decreased Water Quantity; Altered Flow Timing -- Dam or Hydropower Facility Management; Agricultural Practices; Water Management Water: Storage or Withdrawal, Channelization, Management; Migration Impediments Juveniles Eighty percent of the flow has been removed in a three-mile reach below Powerdale Dam. Altered flows due to irrigation (Baldwin, Odell, Tieman, and West Fork Neal creeks), hydropower (Powerdale Dam), and municipal water diversions (upper Dog River) limit productivity of anadromous species.