Limiting Factors



Blue Mountain Province

Grande Ronde Subbasin 422, 423

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 Wallowa Lake Dam and Beaver Creek Dam are barriers to passage.
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Wetland Loss; Impervious Surfaces (Road Density); Riparian Degradation Juveniles, adults Extensive wetlands have been eliminated by agriculture, road building, livestock, and removal of beavers.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management Impervious Surfaces (Road Density); Riparian Degradation Juveniles, adults Past and present forest management practices have decreased riparian function. Bull trout have been affected by loss of shade and instream structure.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices Riparian Degradation; Bank Destabilization Juveniles, adults Agricultural practices and livestock grazing have widened the stream channel in the Upper Grande Ronde.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Pre-Spawn Adults Increased sedimentation has resulted in the siltation of spawning gravel.
Water Quality Temperature -- Agricultural Practices; Forest Management Riparian Degradation All Increased water temperatures in the Upper Grande Ronde have resulted in thermal barriers.
SPRING CHINOOK
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 Adults Wallowa Lake Dam and Upper Alder Slope Diversion are significant barriers to adult fish passage.
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 Extensive wetlands have been eliminated by agriculture, road building, livestock, and removal of beavers.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization; Forest Management Diking; Filling; Impervious Surfaces (Road Density); Riparian Degradation Juveniles Agricultural activities have drained and cleared many riparian areas in the Wallowa River watershed. Agriculture has reduced shade and confined the channel in Catherine Creek.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal; Wetland Loss Juveniles Historic splash damming on the Minam River cleared woody debris and simplified the channel. Extensive channelization in the upper Grande Ronde has resulted in loss of both riverine and wetland habitats.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Spring Chinook are primarily subject to freshwater harvest.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass eight mainstem dams during migration.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Eggs; Pre-spawn Adults Sediment impacts are widespread throughout the Upper Grande Ronde watershed.
Water Quality Turbidity; Temperature -- Agricultural Practices; Urbanization; Forest Management Diking; Filling; Impervious Surfaces (Road Density); Riparian Degradation; Bank Destabilization Eggs Reduced peak flows from operation of Wallowa Lake Dam has increased sediment accumulation below the dam. Temperature and impacts are widespread throughout the Upper Grande Ronde watershed.
Water Quantity Decreased Water Quantity -- Dam or Hydropower Facility Management Water: Storage or Withdrawal Juveniles Water diversions exacerbate summer low flows in the Wallowa River watershed. Water withdrawls significantly reduce the flow of Catherine Creek from June through September, with one diversion transfering water to the Powder River Subbasin. Diversions also reduce flow in the Upper Grande Ronde.
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 Adults Wallowa Lake Dam and Upper Alder Slope Diversion are significant barriers to adult fish passage.
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 Extensive wetlands have been eliminated by agriculture, road building, livestock, and removal of beavers.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Agricultural Practices; Urbanization; Forest Management Diking; Filling; Impervious Surfaces (Road Density); Riparian Degradation Juveniles Impacts to riparian function from grazing and roads limit steelhead rearing habitat in the Wildcat Creek watershed. Extensive grazing has reduced riparian function in some parts of the Joseph Creek watershed. Agricultural activities have drained and cleared many riparian areas in the Wallowa River watershed. Agriculture has reduced shade and confined the channel in Catherine Creek.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Filling; Wood/Structure Removal; Wetland Loss Juveniles Historic splash damming on the Minam River cleared woody debris and simplified the channel. Extensive channelization in the upper Grande Ronde has resulted in loss of both riverine and wetland habitats.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass eight mainstem dams during migration.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management Sediment: Bank Destabilization; Eggs; Pre-spawn Adults Sedimentation limits steelhead spawning and egg incubation in tributaries of the Lower Grande Ronde. Sedimentation is also significant in the Joseph Creek watershed. Sediment impacts are widespread throughout the Upper Grande Ronde watershed.
Water Quality Turbidity; Temperature -- Agricultural Practices; Urbanization; Forest Management Diking; Filling; Impervious Surfaces (Road Density); Riparian Degradation; Bank Destabilization Eggs Reduced peak flows from operation of Wallowa Lake Dam has increased sediment accumulation below the dam. Temperature impacts are widespread throughout the Upper Grande Ronde watershed.
Water Quantity Decreased Water Quantity -- Dam or Hydropower Facility Management Water: Storage or Withdrawal Summer parr Water diversions exacerbate summer low flows in the Wallowa River watershed. Water withdrawals significantly reduce the flow of Catherine Creek from June through September, with one diversion transfering water to the Powder River Subbasin. Diversions also reduce flow in the Upper Grande Ronde.