Province Summary


Willamette Subbasin Summary

The Willamette River Subbasin is approximately 180 miles long and 100 miles wide. With an area of 11,478 square miles (7.3 million acres), the Willamette Basin occupies nearly 12 percent of the state of Oregon. The Willamette River has a mainstem channel length of 185 miles. A tributary to the Columbia River, the Willamette is Oregon»s largest river wholly contained within state boundaries. In addition, it is the nation»s 13th largest river by volume, with more runoff per square mile of drainage than any other large river in the coterminous United States.

Today, about 2.5 million people, or 70 percent of Oregon»s population, live in the Willamette Basin. The Portland metropolitan area has 1.2 million people and is the state’s largest urban area. The three largest population centers of Portland, Salem, and Eugene-Springfield are situated along the banks of the Willamette River and the Interstate 5 corridor. Population growth in the basin is expected to double to nearly 4.0 million by 2050 (Willamette Restoration Initiative, 2001). In the Portland metropolitan region, a 37 percent increase is expected between 2000 and 2020.

Land use is diverse but is dominated by forest and agriculture. Of the basin area devoted to agricultural land use, about 39 percent is used for pasture and hay production, 27 percent is for grass seed, 13 percent is for vegetable crops, 10 percent is for grains, and 5 percent is for fruit. The remainder is used for tree production, nursery crops, and other farm uses. Approximately 36 percent of the basin is in federal ownership. Most of the federal land is located in the higher elevations of the Cascade and Coast ranges and is managed by the U.S. Forest Service (USFS) and U.S. Bureau of Land Management (BLM). More than 60 percent of the basin area outside urban growth boundaries—and more than 90 percent of the valley floor—is privately owned.

Source: Willamette Subbasin Plan

Status and Trends of Focal Species in Willamette Subbasin
 
Species ESU MPG Population Biological Objective (s) Biological Status Federal Status Data / Charts
Fall Chinook Lower Columbia  Cascade Fall  Clackamas  Draft Recovery Plan Criteria :
1,551 natural adults (Clackamas population)299
 
Unknown Threatened No Data
Spring Chinook Upper Willamette  Upper Willamette Spring  Clackamas, Molalla, North Santiam, South Santiam, Calapooia, McKenzie, Middle Fork Willamette  Draft Recovery Plan Criteria :
Natural Adults
Clackamas - 2,314 330; Molalla - 699 330; North Santiam - 5,428 330, South Santiam - 3,116 330, Calapooia - 598 330, Mckenzie - 10,017 330, Middle Fork Willamette - 5,820330
 
NOSA Estimate
2016: Clackamas River - 4,328 spawners474
Mckenzie River - 1,716 spawners474
North Santiam River - 327 spawners474
Mkenzie River - 1,716 spawners474
South Santiam River - 499 spawners474
Middlefork Willamette River - 226 spawners474
Adult Counts
Clackamas River
2016: 4,462 adults (mixed - North Fork Dam) 137

Willamette Falls
2016: 30,317 adults (mixed) 137

North Santiam River
2016: 2,824 adults (mixed - Minto Dam) 137

McKenzie River
2016: 1,977 adults (mixed)137

South Santiam River
2016: 137 adults (mixed-foster dam)
Threatened Status & Trends
Chum Columbia  Cascade  Clackamas  Draft Recovery Plan Criteria :
To Be Determined 299
 
Unknown Threatened No Data
Coho Lower Columbia  Cascade  Clackamas  Draft Recovery Plan Criteria :
11,232 natural adults 299
 
NOSA Estimate
2016: Clackamas - 1,628 Early and Late spawners 474
Threatened Status & Trends
Coastal Cutthroat       Subbasin Plan Objective :
None
 
Unknown Species of Concern No Data
Winter Steelhead Lower Columbia (Clackamas); Upper Willamette  Cascade Winter (Clackamas); Upper Willamette  Clackamas, Molalla, North Santiam, South Santiam, Calapooia  Draft Recovery Plan Criteria :
Natural Adults
Clackamas - 10,671 299, Molalla - 3,226 330 , North Santiam - 8,362 330, South Santiam - 3,912 330, Calapooia - 522 330
 
NOSA Estimate
2008: South Santiam River - 1,534 spawners474
North Santiam River - 2,789 spawners474
Molalla River - 1,273 spawner474
Calopoola river - 236 spawner474
2016: Clackamas River - 2,531 spawners474
Adult Count
Willamette Falls
2016: 5,778 adults
Willamette Falls (Late) - 3,755 adults496
Willamette Falls (Early) - 2,023 adults497

North Fork Santiam River (North Fork Dam)
2015: 2,966 adults (natural and hatchery)496

South Santiam River(Foster Dam)
2015: 400 adults (natural and hatchery)136

Redd Counts
Little North Fork Santiam
2010: 12 redds 230, 231

Calapooia River
2011: North Fork Calapooia River - 2 redds 232
2010: 49 redds 232

South Santiam River Basin
2011: Wiley Creek - 14 redds 233
2010: 6 redds 233
Threatened Status & Trends
Bull Trout Upper Willamette River, Clackamas River    Mainstem McKenzie River, Trail Bridge, South Fork McKenzie River, and possibly Middle Fork Willamette River (all in Upper Willamette Core Area)  Draft Recovery Plan Criteria :
900-1,500 adults (600-100 in Upper Willamette Core Area; 300-500 in Clackamas Core Area)331
 
Redd Counts
2009: 240 redds 189
Threatened Status & Trends
Oregon Chub Willamette Subbasin      Recovery Plan Criteria :
20 populations of the least 500 adults, all exhibiting stable or increasing trend; at least four populations each in Mainstem Willamette, Middle Fork Willamette, and Santiam436
 
2015: Delisted
2013: Oregon chub exceed recovery criteria as defined in the species' Recovery Plan - 41 populations with 500 or more individuals; 23 populations met the second criterion. Of the populations meeting criteria 1 and 2, 10 are located in the Middle Fork Willamette recovery area, 7 are located in the Santiam Recovery Area, ands 6 are located in the Mainstem Willamete Recovery Area 282
Threatened No Data
    
View abundance data for Willamette Subbasin
 
Hatcheries located in Willamette Subbasin
**Hatchery data will be updated in 2016**

Hatchery / Acclimation Pond Hatchery Info Releases / Returns Program Reviews(APRE / HSRG / HGMP / USFWS) Map
Cassidy Pond View   View  
Clackamas Hatchery View View View View
Dexter Hatchery View View View View
Eagle Creek National Fish Hatchery View View View View
Leaburg Hatchery View View View View
Marion Forks Hatchery View View View View
McKenzie Salmon Hatchery View   View View
McKenzie Trout Hatchery View View   View
Minto Pond View View View View
Oakridge Fish Hatchery View     View
Oregon State Fish Hatchery View     View
Roaring River State Fish Hatchery View View View View
South Santiam Hatchery View View View View
Tuffy Creek Hatchery View     View
Willamette Fish Hatchery View View View View
 
Hatchery Releases and Returns to Willamette Subbasin358
**Hatchery data will be updated in 2016**

Some releases into subbasins may be from hatcheries located in other provinces and subbasins. Hatchery releases of anadromous fish, within the geographic range of an ESU/DPS, are listed accordingly.
 
Hatchery / Acclimation Pond Species ESU/DPS Released in 2009 Returns to Collection Facility in 2009 Data as of
Clackamas Hatchery Spring Chinook Lower Columbia River Chinook ESU 677,491 1,576 8 / 30 / 2010
Summer Steelhead Lower Columbia River Steelhead DPS 182,688 599 8 / 30 / 2010
Winter Steelhead Lower Columbia River Steelhead DPS 174,043 352 8 / 30 / 2010
Dexter Hatchery Spring Chinook 1,690,208 3,963 8 / 30 / 2010
Summer Steelhead 116,522 416 8 / 30 / 2010
Eagle Creek National Fish Hatchery Coho Lower Columbia River Coho ESU 324,944 8 / 30 / 2010
Winter Steelhead Lower Columbia River Steelhead DPS 90,589 8 / 30 / 2010
Leaburg Hatchery Rainbow Trout 69,300 8 / 30 / 2010
Summer Steelhead Upper Willamette River Steelhead DPS 111,703 1,008 8 / 30 / 2010
Marion Forks Hatchery Brook Trout 3,380 8 / 30 / 2010
Cutthroat Trout 4,919 8 / 30 / 2010
Rainbow Trout 15,212 8 / 30 / 2010
Spring Chinook Upper Willamette River Chinook ESU 152,073 2,204 8 / 30 / 2010
McKenzie Trout Hatchery Spring Chinook Upper Willamette River Chinook ESU 1,238,220 3,334 8 / 30 / 2010
Minto Pond Spring Chinook Upper Willamette River Chinook ESU 677,454 8 / 30 / 2010
Summer Steelhead Upper Willamette River Steelhead DPS 159,500 8 / 30 / 2010
Roaring River State Fish Hatchery Rainbow Trout 424,343 8 / 30 / 2010
Summer Steelhead Upper Willamette River Steelhead DPS 67,079 8 / 30 / 2010
Winter Steelhead Upper Willamette River Steelhead DPS 66,118 8 / 30 / 2010
South Santiam Hatchery Rainbow Trout 2,969 8 / 30 / 2010
Spring Chinook Upper Willamette River Chinook ESU 761,676 2,762 8 / 30 / 2010
Summer Steelhead Upper Willamette River Steelhead DPS 148,126 5,420 8 / 30 / 2010
Willamette Fish Hatchery Rainbow Trout 524,163 8 / 30 / 2010
Spring Chinook Upper Willamette River Chinook ESU 611,641 8 / 30 / 2010
Recovery Status for ESA-Listed Salmon and Steelhead in the Willamette Subbasin370, 368

Updated : 5/27/2010

Species Population Abundance Threshold Mean Abundance Major Spawning Area Growth Rate Recruits / Spawners Current Viability
Winter Steelhead Clackamas River 750 3,897 -- -- -- Medium
  Mollala River -- 1,000 -- -- -- Medium
  North Fork Santiam River -- 2,150 -- -- -- Medium
  South Fork Santiam River -- 2,150 -- -- -- High
  Callapooia River -- 600 -- -- -- Medium
Fall Chinook Clackamas River 800 558 -- -- -- Very Low
Spring Chinook Clackamas River -- 2,800 -- -- -- High
  Mollala River -- <50 -- -- -- Very Low
  North Fork Santiam River -- <50 -- -- -- Very Low
  South Fork Santiam River -- <50 -- -- -- Very Low
  Callapooia River -- <50 -- -- -- Very Low
  McKenzie River -- 2,200 -- -- -- Medium
  Middle Fork Willamette River -- <50 -- -- -- Very Low
Coho Clackamas River 3,300 6,548 -- -- -- Medium
Chum Clackamas River -- -- -- -- -- Very Low
Limiting Factors in the 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.