Limiting Factors



Columbia Plateau Province

John Day Subbasin 376, 389, 390

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 Agricultural Practices Migration Impediments Juveniles, adults Many locations in the John Day River and its tributaries are seasonally dammed (push-up dams) for irrigation.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices Riparian Degradation Juveniles, adults Forest management, agriculture, and livestock grazing practices have degraded riparian cover and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices Riparian Degradation; Bank Destabilization Juveniles, adults Pool habitat has been lost, and large woody debris is minimal..
Toxic Contaminants Water -- Mining Activities Pollution: Heavy Metal All Mining practices have degraded water quality.
Water Quality Temperature -- Agricultural Practices; Forest Management Filling; Riparian Degradation All Water temperatures have increased from destruction of cold water springs.
Water Quantity Decreased Water Quantity -- Dam or Hydropower Facility Management Water: Storage or Withdrawal All Summer low flows caused by irrigation diversions result in passage and spawning difficulties.
REDBAND TROUT
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 Riparian Degradation; Bank Destabilization Juveniles, adults Pool habitat has been lost, and large woody debris is minimal..
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices Riparian Degradation Juveniles, adults Forest management, agriculture, and livestock grazing practices have degraded riparian cover and function.
Toxic Contaminants Water -- Mining Activities Pollution: Heavy Metal All Mining practices have degraded water quality.
Water Quality Temperature -- Agricultural Practices; Forest Management Filling; Riparian Degradation All Water temperatures have increased from destruction of cold water springs.
Water Quantity Decreased Water Quantity -- Dam or Hydropower Facility Management Water: Storage or Withdrawal All Summer low flows caused by irrigation diversions result in passage and spawning difficulties.
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; Impervious Surfaces (Road Density); Riparian Degradation; Wetland Loss Juveniles Floodplains in the lower John Day River have been extensively altered by agriculture, livestock grazing, and transportation corridors.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation Juveniles Riparian areas in the lower John Day River have been extensively altered by agriculture, livestock grazing, and transportation corridors. Levels of large woody debris are severely reduced in the Middle Fork watershed.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal Juveniles Habitat quantity and diversity are key limiting factors in the Middle Fork, South Fork, North Fork, and Upper John Day watersheds.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass three mainstem dams during migration
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Urbanization Sediment: Bank Destabilization; Impervious Surfaces (Road Density) Eggs, juveniles Sediment load is a high priority limiting factor throughout the subbasin, especially in most tributaries of the Lower John Day and North Fork watersheds.
Toxic Contaminants Water -- Mining Activities Pollution: Heavy Metal Eggs, juveniles Leaching of toxic mine waste is a problem in the North Fork watershed.
Water Quality Turbidity; Temperature; pH; Oxygen -- Agricultural Practices; Forest Management Diking; Filling; Riparian Degradation; Bank Destabilization Eggs, juveniles Turbidity is very high in Cottonwood Creek after storm events. The Lower John Day and numerous tributaries throughout the subbasin are on the Oregon state 303(d) list for exceeding temperature, pH, dissolved oxygen, and fecal coliform standards.
Water Quantity Decreased Water Quantity -- Agricultural Practices Water: Storage or Withdrawal Eggs, juveniles Summer low flows caused by irrigation diversions result in passage and spawning difficulties in Lower John Day tributaries.
SUMMER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Biological Viability Criteria Diversity -- Artificial Propogation Straying Adult spawners Out-of-basin stray steelhead 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 Partial passage barriers created by water diversions limit movements of juvenile salmonids in Bridge, Kahler, Muddy, Lower Rock, and Thirtymile creeks (Lower John Day), and in the South 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; Impervious Surfaces (Road Density); Riparian Degradation; Wetland Loss Juveniles Floodplains in the lower John Day River have been extensively altered by agriculture, livestock grazing, and transportation corridors.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation Juveniles Riparian areas in the lower John Day River have been extensively altered by agriculture, livestock grazing, and transportation corridors. Levels of large woody debris are severely reduced in the Middle Fork watershed.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal; Wetland Loss Juveniles Habitat diversity and large woody debris is lacking in Bridge, Mountain, Rock, Cottonwood, Ferry Canyon, Pine Hollow and Thirtymile creeks. Habitat quantity and diversity are key limiting factors in the Middle Fork, South Fork, North Fork, and Upper John Day watersheds.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass three mainstem dams during migration
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Forest Management; Urbanization Sediment: Bank Destabilization; Impervious Surfaces (Road Density) Eggs, juveniles Sediment load is a high priority limiting factor throughout the subbasin, especially in most tributaries of the Lower John Day and North Fork watersheds.
Toxic Contaminants Water -- Mining Activities Pollution: Heavy Metal Eggs, juveniles Leaching of toxic mine waste is a problem in the North Fork watershed.
Water Quality Turbidity; Temperature; pH; Oxygen -- Agricultural Practices; Forest Management Diking; Filling; Riparian Degradation; Bank Destabilization Eggs, juveniles Turbidity is very high in Cottonwood Creek after storm events. The Lower John Day and numerous tributaries throughout the subbasin are on the Oregon state 303(d) list for exceeding temperature, pH, dissolved oxygen, and fecal coliform standards.
Water Quantity Decreased Water Quantity -- Agricultural Practices Water: Storage or Withdrawal Eggs, juveniles Summer low flows caused by irrigation diversions result in passage and spawning difficulties in Lower John Day tributaries.
WESTSLOPE 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 Riparian Degradation; Bank Destabilization Juveniles, adults Pool habitat has been lost, and large woody debris is minimal..
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices Riparian Degradation Juveniles, adults Forest management, agriculture, and livestock grazing practices have degraded riparian cover and function.
Toxic Contaminants Water -- Mining Activities Pollution: Heavy Metal All Mining practices have degraded water quality.
Water Quality Temperature -- Agricultural Practices; Forest Management Filling; Riparian Degradation All Water temperatures have increased from destruction of cold water springs.
Water Quantity Decreased Water Quantity -- Dam or Hydropower Facility Management Water: Storage or Withdrawal All Summer low flows caused by irrigation diversions result in passage and spawning difficulties.