Naches River FMO Habitat: Difference between revisions
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== Overview == | == Overview == | ||
The Naches River is the main tributary of the Yakima River entering just north of the city of Yakima. It begins approximately 45 miles upstream at the confluence of the Bumping and Little Naches rivers (the American River flows into the Bumping River about 3.5 miles above this point). Other major tributaries of the Naches River include the Tieton River and Rattlesnake Creek. With the exception of storage dams, which block upstream migration on the Bumping and Tieton rivers, bull trout are able to migrate freely within the system. Below these dams there are 16.5 miles of habitat available to fish on the Bumping River and 21 miles on the Tieton River. Numerous smaller tributary streams also flow into the Naches River. | The Naches River is the main tributary of the Yakima River entering just north of the city of Yakima. It begins approximately 45 miles upstream at the confluence of the Bumping and Little Naches rivers (the American River flows into the Bumping River about 3.5 miles above this point). Other major tributaries of the Naches River include the Tieton River and Rattlesnake Creek. With the exception of storage dams, which block upstream migration on the Bumping and Tieton rivers, bull trout are able to migrate freely within the system. Below these dams there are 16.5 miles of habitat available to fish on the Bumping River and 21.5 miles on the Tieton River. Numerous smaller tributary streams also flow into the Naches River. | ||
=== Habitat Conditions === | === Habitat Conditions === | ||
The shared FMO habitat for all of the [[Naches Bull Trout Population Group|Naches River fluvial bull trout populations]] is considered to be primarily located in the Naches River although there is some evidence that the Tieton River and mainstem Yakima River are used as well. It is difficult to summarize habitat conditions in the Naches River given the length of the river (45 miles). Generally, the upper 27 miles (above the Tieton River confluence) flows through forested lands of mixed ownership. | The shared FMO habitat for all of the [[Naches Bull Trout Population Group|Naches River fluvial bull trout populations]] is considered to be primarily located in the Naches River although there is some evidence that the Tieton River and mainstem Yakima River are used as well. It is difficult to summarize habitat conditions in the Naches River given the length of the river (45 miles). Generally, the upper 27 miles (above the Tieton River confluence) flows through forested lands of mixed ownership. ''About 25% of the river's floodplain is on National Forest land, 25% is state owned land, and 50% of the Naches River floodplain is privately owned.'' There is also considerable recreational access and use. State Route (SR) 410 runs adjacent to the river for the entire length of this segment. ''The floodplain is constricted and riparian vegetation has been lost due to the highway and rip-rap structures for home protection.'' Below the Tieton River confluence land use along the Naches River converts to predominantly agricultural (orchards, irrigated pasture, and hay production) and there are numerous water diversions. U.S. Highway 12 runs adjacent to the river from the Tieton River confluence downstream to the mouth impairing floodplain function. Haring (2001<ref name=":0">Haring, Don. ''Habitat Limiting Factors Yakima River Watershed, Water Resource Inventory Areas 37-39 : Final Report''. Washington State Conservation Commission, Dec. 2001, p. 364, <nowiki>https://ybfwrb.org/wp-content/uploads/2017/10/Haring-2001.pdf</nowiki>.</ref>) described numerous positive habitat attributes such as good riparian condition (in the upper portion of the river), good pool frequency and depth, good LWD and substantial amounts of off-channel habitat. These positive attributes combined with the length of river available for bull trout habitation suggest that FMO habitat conditions in the mainstem Naches River ''may not be'' limiting population productivity for Naches River fluvial bull trout populations. | ||
=== Tieton River FMO Habitat === | |||
The significance of the Tieton River as FMO habitat for the Naches River fluvial populations is unknown. However, adult bull trout have been captured in the Tieton River (in the stilling basin directly below Tieton Dam) that genetically assigned to the Rattlesnake Creek and American River populations (Small et al. 2009). The Tieton River flows for | The significance of the Tieton River as FMO habitat for the Naches River fluvial populations is unknown. However, adult bull trout have been captured in the Tieton River (in the stilling basin directly below Tieton Dam) that were genetically assigned to the Rattlesnake Creek and American River populations (Small et al. 2009<ref>Small, M. P., et al. ''WDFW Yakima Bull Trout Report. Phase 3: Genetic Analysis of Yakima Basin Bull Trout (Salvelinus Confluentus)''. Washington Department of Fish and Wildlife, 2009, <nowiki>https://ybfwrb.org/wp-content/uploads/2017/10/Small_et_al_2009.doc</nowiki>.</ref>). The Tieton River flows for 21.5 miles from the base of the dam to its confluence with the Naches River. U.S. Highway 12 parallels the river on the left bank for much of this length, which has altered the riparian corridor. However, this road has little effect on floodplain function as the river is naturally confined in this section. Other roads, structures, several developed campgrounds, and the Yakima-Tieton diversion dam contribute to the rivers disturbed condition. The channel is in poor condition due to structural restrictions and an almost complete absence of LWD (Haring 2001<ref name=":0" />). The most significant negative impact on fish habitat in the Tieton River is the regulated flow regime, which also contributes to the lack of LWD and channel complexity. The timing and magnitude of stream discharge in the river is the most highly altered of any in the Yakima Basin. Winter flows are 60-80% less than would occur under unregulated conditions and flow variability is extremely low. At a time when overwintering bull trout would be seeking pool habitat with cover, relatively none exists. During the first week of September an extreme, managed hydrologic event (“flip-flop”) occurs when dam releases are rapidly increased and average river flows often exceed by an order of magnitude what would be a natural base flow, sometimes exceeding 2,000 cfs. This condition persists to varying degrees for over a month. | ||
== Threats - NEED GROUP INPUT == | == Threats - NEED GROUP INPUT == | ||
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''Threat Severity: Unknown, likely insignificant'' | ''Threat Severity: Unknown, likely insignificant'' | ||
''Bull trout populations using Naches River as FMO habitat are not limited by natural barriers within the FMO habitat. Tieton and Bumping dams reduce metapopulation dynamics and | ''Bull trout populations using Naches River as FMO habitat are not limited by natural barriers within the FMO habitat. Tieton and Bumping dams reduce metapopulation dynamics and gene flow. Nelson dam, a fish passage barrier on the mainstem Naches River near the Yakima River confluence was removed in 2023.'' | ||
''Low flows in parts of the Naches River during late summer may impact connectivity, however, bull trout intending to spawn usually migrate to their spawning grounds in June and July when flows are more adequate.'' | ''Low flows in parts of the Naches River during late summer may impact connectivity, however, bull trout intending to spawn usually migrate to their spawning grounds in June and July when flows are more adequate.'' | ||
''The Wapatox Diversion is located in the lower reach of the Naches River (headgates at RM 17). In a 2010 radio telemetry study, 13 bull trout were captured from the pool below the dam in the month of April (Mizell and Anderson 2010''<ref>Mizell, M., and E. Anderson. ''Summary of Bull Trout Tagged under the USFWS Funded Radio Telemetry Project in the Yakima Basin.'' Washington Department of Fish and Wildlife, 2010, <nowiki>https://ybfwrb.org/wp-content/uploads/2017/10/Mizell_Anderson_2010_appendices.pdf</nowiki>.</ref>''). Telemetry showed bull trout were able to move upstream of the diversion, but the fact that so many bull trout were captured there indicates there may be some effect of the dam on natural movements by bull trout. However, the report also notes that the Wapatox pool might be attractive to bull trout due to it being a thermal refuge / "prey highway". This area should be reassessed to determine any impacts to connectivity.'' | |||
==== Entrainment ==== | ==== Entrainment ==== | ||
''Threat Severity: | ''Threat Severity: Unknown, likely insignificant'' | ||
''Several diversions exist along the Naches river.'' | ''Several diversions exist along the Naches river. USBR biologists checked behind the screens of Wapatox Dam from ~2002-2009 and never found an entrained bull trout, but did find one bull trout trapped upstream of the screen that did not make it out of the bypass before the canal got shut off at the end of the season (Scott Kline, personal comm).'' | ||
==== Dewatering due to flow management ==== | ==== Dewatering due to flow management ==== | ||
''Threat Severity: Insignificant | ''Threat Severity: Insignificant'' | ||
''Naches River FMO habitat is not known to dewater.'' | ''Naches River FMO habitat is not known to dewater.'' | ||
==== Other ==== | |||
=== Land-use Issues === | === Land-use Issues === | ||
==== Forestry ==== | ==== Forestry ==== | ||
''Threat Severity: Unknown'' | ''Threat Severity: Unknown'' | ||
[[File:Timber Harvest in Naches River Watershed.png|thumb|Figure | [[File:Timber Harvest in Naches River Watershed.png|thumb|Figure 1. Timber harvest boundaries in the Naches River watershed. Colors denote different harvest time frames. Colors on the map range from 1991- Present.]] | ||
''There has been some timber harvest in the Naches River watershed over the past 35 years (Figure | ''There has been some timber harvest in the Naches River watershed over the past 35 years (Figure 1). The harvest has primarily occurred upland of the river and away from known spawning tributaries, but there may be some impacts to FMO habitat, like increased sedimentation from erosion and roads, and reduced recruitment of large wood to the river. Those impacts are unquantified.'' | ||
==== Agriculture and Grazing ==== | ==== Agriculture and Grazing ==== | ||
''Threat Severity: | ''Threat Severity: Insignificant'' | ||
''Minimal livestock grazing occurs along the Naches River. Habitat degradation significant at the reach scale is not believed to occur, as federal livestock allotments are focused in the uplands, away from the highway. About 50% of the grazing allotments in the Naches Watershed are for sheep, which are moved constantly by shepherds and should have minimal impact to the riparian areas. However, the Nile and Rattlesnake Creek allotments are proposed to change to cattle to protect native bighorn sheep populations.'' ''The Okanogan-Wenatchee National Forest has been working on an updated environmental impact statement (2025) for'' ''these'' ''grazing allotments, which has included input from members of the Yakima Bull Trout Working Group in an attempt to minimize any negative effects to bull trout.'' | |||
==== Recreation ==== | ==== Recreation ==== | ||
''Threat Severity: Unknown, likely significant.'' | ''Threat Severity: Unknown, likely significant.'' | ||
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''Recreational impacts to bull trout in Naches River FMO habitat are not quantified but are likely to be a threat. There has been riparian and aquatic habitat degradation due to recreation, including heavy use of established and dispersed camping sites and day use areas. When fires are allowed, campers remove and burn downed wood that may otherwise be recruited to the river. Rock dams are a persistent issue, but few are channel spanning. Pollution including trash, human waste, and road run-off may be impacting water quality.'' | ''Recreational impacts to bull trout in Naches River FMO habitat are not quantified but are likely to be a threat. There has been riparian and aquatic habitat degradation due to recreation, including heavy use of established and dispersed camping sites and day use areas. When fires are allowed, campers remove and burn downed wood that may otherwise be recruited to the river. Rock dams are a persistent issue, but few are channel spanning. Pollution including trash, human waste, and road run-off may be impacting water quality.'' | ||
''There is heavy recreational use in the Little Naches drainage, including | ''There is heavy recreational use in the Little Naches drainage, including 18 miles of jeep trails and many more miles of motocross trails, which may increase sedimentation and down-stream impacts in Naches FMO habitat.'' | ||
''There have been no reports of non-angling harassment of bull trout, but due to proximity of camp sites | ''There have been no reports of non-angling harassment of bull trout, but due to proximity of camp sites to the river and bull trout's large size fish may be harassed.'' | ||
==== Roads and Development ==== | ==== Roads and Development ==== | ||
''Threat Severity'': | ''Threat Severity'': ''Unknown'' | ||
''Residential development is present in FMO habitat | ''Residential development is present in FMO habitat and may cause an incremental degree of degradation from loss of floodplain connection and riparian vegetation clearing near homes. Considering the large extent of FMO habitat, there is still sufficient habitat for bull trout. The Naches River floodplain is restricted due to highway 410 and heavy development and levees near the City of Naches. Agricultural land flanks the river downstream of Naches. High road density in Little Naches (2.5 miles / sq mile) and many stream adjacent roads have increased the drainage channel network by 30 percent, which likely causes the watershed to shed flows more efficiently, and decrease water storage function. Fine sediment monitoring by Yakama Nation indicates Little Naches watershed is properly functioning. Overall road density in the Naches Ranger district is high, although impacts to FMO habitat are unknown.'' | ||
==== Mining ==== | ==== Mining ==== | ||
''Threat Severity: Insignificant'' | ''Threat Severity: Insignificant'' | ||
'' | ''Potential threats to FMO habitat were significantly diminished in 2020 when Washington State passed a ban on suction dredge mining in critical habitat for ESA listed species including bull trout. There is no known mining occurring in FMO habitat.'' | ||
==== Other ==== | ==== Other ==== | ||
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''Threat Severity: Unknown'' | ''Threat Severity: Unknown'' | ||
''Brook trout are present in the Naches River but no hybrids have been identified through genetics analyses. | ''Brook trout are present in the Naches River but no hybrids have been identified through genetics analyses. The significance of the threat is unknown.'' | ||
==== Other Invasive Species ==== | ==== Other Invasive Species ==== | ||
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''Threat Severity: Unknown, likely significant'' | ''Threat Severity: Unknown, likely significant'' | ||
''Anadromous fish runs are severely depleted from historic levels. Juvenile anadromous salmonid prey is scarce or not available. Dearth of anadromous carcasses | ''Anadromous fish runs are severely depleted from historic levels. Juvenile anadromous salmonid prey is scarce or not available. Dearth of anadromous carcasses deprives streams of marine-derived nutrients that likely drive invertebrate productivity. Impact is unknown but could be significant.'' | ||
==== Disease ==== | ==== Disease ==== | ||
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''Threat Severity'': ''Unknown, likely insignificant'' | ''Threat Severity'': ''Unknown, likely insignificant'' | ||
Altered flows in FMO habitat are result of reservoir releases from Bumping and Tieton Dams. Impacts associated with this mechanism are unknown but believed to be insignificant. There are high flows in lower Naches during flip-flop but pre-spawn bull trout are well upstream by the time they occur. | Altered flows in FMO habitat are the result of reservoir releases from Bumping and Tieton Dams. Impacts associated with this mechanism are unknown but believed to be insignificant. There are high flows in lower Naches during flip-flop but pre-spawn bull trout are well upstream by the time they occur. | ||
'' | ''Natural peak flows are occurring earlier than historical flow records by about one month (Gary Torretta, personal comm). This creates a longer period of base flow conditions subject to warming from summer and fall temperatures. Water quality might be diminished during low flows as well. This trend is clearly seen in most years in Little Naches and American Rivers, and in Naches River above the Tieton River.'' | ||
==== Current and modeled future temperature conditions ==== | ==== Current and modeled future temperature conditions ==== | ||
''Threat Severity'': ''Unknown, likely significant | ''Threat Severity'': ''Unknown, likely significant'' | ||
''The mean August temperatures in the Naches River | ''The mean August temperatures in the Naches River were predicted to be between 16-23°C according to the 2011 NorWest model. A dataset containing 236 water temperature observations between 2019 and 2024 showed a mean temperature range between 11°C - 18°C from the months of June through September (WDFW, Ecological Interaction Team). Samples ranged from the mouth of the Naches River up to the confluence with the Little Naches River. Many bull trout are known to skip spawning in some years (Fraley and Shepard 1989''<ref name=":1">Fraley, John J., and Bradley B. Shepard. “Life History, Ecology and Population Status of Migratory Bull Trout (Salvelinus Confluentus) in the Flathead Lake and River System.” ''Northwest Science'', vol. 63, no. 4, 1989, pp. 133–43.</ref>'', Benjamin et al. 2020''<ref name=":2">Benjamin, Joseph R., et al. “Thermal Heterogeneity, Migration, and Consequences for Spawning Potential of Female Bull Trout in a River-Reservoir System.” ''Ecology and Evolution'', vol. 10, 2020, pp. 4128–42.</ref>''), so they likely stay in FMO habitat if it is suitable. Temperature in parts of the mainstem Naches River is increasingly unsuitable during the summer and fall.'' | ||
==== Other changes in hydrology ==== | ==== Other changes in hydrology ==== | ||
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''Threat Severity'': ''Insignificant'' | ''Threat Severity'': ''Insignificant'' | ||
'' | ''The WDFW Ecological Interactions Team visits a large number of sites in the Naches watershed each year. Their goal is to understand anadromous productivity throughout the Yakima River Basin. Their target species is O. Mykiss but they do encounter around 10 juvenile - subadult bull trout per year in their sampling efforts, primarily in the Naches headwaters (American River, Crow and Rattlesnake creeks) (Gabe Temple, personal comm.). Non-O.Mykiss species are usually not netted and the crew will move to a different part of the stream as to not disturb them. They do not collect biodata on bull trout, aside from a few years around 2015 where USFWS was directing the team to PIT tag any bull trout.'' | ||
=== Other Threats === | === Other Threats === | ||
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== Summary of Primary Limiting Factors and Threats == | == Summary of Primary Limiting Factors and Threats == | ||
''The primary limiting factors and threats facing bull trout in the Naches River FMO habitat are likely recreation, diminished prey base, angling, and water temperature. The summer season brings heavy recreational use | ''The primary limiting factors and threats facing bull trout in the Naches River FMO habitat are likely recreation, diminished prey base, angling, and water temperature. The summer season brings heavy recreational use to the Naches Ranger District. Riverside camping and heavy day use contributes to riparian vegetation loss, rock dam construction, and pollution in the floodplain. Anadromous fish runs are depressed compared to the historical numbers, leading to reduced prey base for sub-adult and adult bull trout. Lack of marine derived nutrients may also contribute to reduced prey base. Finally, climate change effects like low-snowpack and hot, dry summers are contributing to unsuitable water temperatures and low flows in the mainstem Naches river, primarily during the months of August and September. Although spawning fish are likely in colder tributaries at this time, 30-50% of female bull trout are known to skip spawning in some years (Fraley and Shepard 1989''<ref name=":1" />'') and may not migrate at all (Benjamin et al 2020''<ref name=":2" />''). The impacts of angling on bull trout in Naches River FMO habitat are unquantified but illegal harvest of bull trout in the Naches River has been documented by WDFW law enforcement on several occasions.'' | ||
''Lack of fish passage at Tieton and Bumping dams is a threat to metapopulation dynamics and gene flow.'' | |||
''Forestry, grazing, and roads are likely lower-level threats that should be quantified. Brook Trout are present in Naches FMO habitat but have not been observed in Rattlesnake or Crow Creek spawning areas. They have been observed spawning in the same area as bull trout on the American River which indicates potential hybridization is occurring.'' | ''Forestry, grazing, and roads are likely lower-level threats that should be quantified. Brook Trout are present in Naches FMO habitat but have not been observed in Rattlesnake or Crow Creek spawning areas. They have been observed spawning in the same area as bull trout on the American River which indicates potential hybridization is occurring.'' | ||
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=== FMO Habitat Recovery Strategy === | === FMO Habitat Recovery Strategy === | ||
''Naches River FMO habitat would benefit from riparian restoration and floodplain connection to increase shade and available habitat for all salmonids. Restoring salmon and steelhead habitat would increase anadromous fish runs to provide marine nutrients to the ecosystem and prey | ''Naches River FMO habitat would benefit from riparian restoration and floodplain connection to increase shade and available habitat for all salmonids. Restoring salmon and steelhead habitat would increase anadromous fish runs to provide marine nutrients to the ecosystem and prey for bull trout. Education and outreach to recreationists and anglers should be a priority, emphasizing leave-no-trace principles, fishing regulations and fish identification. Managers should consider an angler survey to quantify bull trout catch. Water quality in the Naches River should be monitored including water temperature and sediment load. Studies should be done to investigate the distribution of brook trout and introgression with the Naches bull trout populations.'' | ||
=== Monitoring Needs/Key Questions === | === Monitoring Needs/Key Questions === | ||
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=== Completed Bull Trout Recovery Actions === | === Completed Bull Trout Recovery Actions === | ||
Naches FMO Action #4: Provide Passage at Nelson Dam | |||
=== Recommended Actions === | === Recommended Actions === | ||
Basin-wide Action #1: Restore Healthy Salmon Populations | |||
Basin-wide Action #2: Evaluate Climate Change Impacts | |||
Basin-wide Action #4: Monitor Yakima Basin Bull Trout Genetics Over Time | |||
Basin-wide Action #5: Nutrient Enhancement | |||
Basin-wide Action #6: Outreach and Conservation | |||
Basin-wide Action #7: Redd Surveys | |||
Basin-wide Action #9: Habitat Monitoring | |||
==== Naches FMO Actions ==== | |||
Naches FMO Action #1: Evaluate and Reduce Entrainment at Tieton Dam | |||
Naches FMO Action #2: Evaluate Flow Management Improvements for the Naches | |||
Naches FMO Action #3: Support Ongoing Habitat Restoration and Protection | |||
Naches FMO Action #5: Conduct eDNA Assessment to Determine Occupancy and Distribution | |||
=== Actions in the Yakima Steelhead Recovery Plan that benefit this habitat === | === Actions in the Yakima Steelhead Recovery Plan that benefit this habitat === | ||
Naches Action #5: Restore lower Naches River floodplain | |||
Naches Action #7: Protect habitats in Naches River mainstem above Tieton Confluence | |||
Naches Action #8: Maintain, upgrade or abandon forest roads | |||
Naches Action #9: Provide passage at Bumping Dam | |||
Naches Action #10: Improve habitat in lower Bumping | |||
Naches Action #11: Restore side channels and floodplain of Little Naches River | |||
Naches Action #12: Place large woody debris in Little Naches ''(as of 2025, approximately 2000 logs/trees have been placed in the mainstem LNR, Quartz Creek and Crow Creek).'' | |||
Naches Action #13: Reduce dispersed recreation impacts in key tributaries | |||
Naches Action #17: Increase instream flows in lower Rattlesnake Creek | |||
Naches Action #18 Improve sediment transport at Rattlesnake Creek/Naches River confluence | |||
== Update Notes == | == Update Notes == | ||
''2012 BTAP text copied into Yakipedia and edited to match new format in February 2025 by Aimee Taylor. ADD LINK TO 2012 BTAP pdf placemark'' | ''2012 BTAP text copied into Yakipedia and edited to match new format in February 2025 by Aimee Taylor. ADD LINK TO 2012 BTAP pdf placemark'' | ||
Additional edits proposed by Alex Conley, Aimee Taylor and | Additional edits proposed by Alex Conley, Aimee Taylor and Naches bull trout populations small group. ''Reviewed, and updated and approved by BTWG in XXXXXXXXXXXXX'' | ||
Specific detail on out of cycle updates: | Specific detail on out of cycle updates: | ||
== References- == | == References- == | ||
Latest revision as of 14:20, 10 April 2025
Overview
The Naches River is the main tributary of the Yakima River entering just north of the city of Yakima. It begins approximately 45 miles upstream at the confluence of the Bumping and Little Naches rivers (the American River flows into the Bumping River about 3.5 miles above this point). Other major tributaries of the Naches River include the Tieton River and Rattlesnake Creek. With the exception of storage dams, which block upstream migration on the Bumping and Tieton rivers, bull trout are able to migrate freely within the system. Below these dams there are 16.5 miles of habitat available to fish on the Bumping River and 21.5 miles on the Tieton River. Numerous smaller tributary streams also flow into the Naches River.
Habitat Conditions
The shared FMO habitat for all of the Naches River fluvial bull trout populations is considered to be primarily located in the Naches River although there is some evidence that the Tieton River and mainstem Yakima River are used as well. It is difficult to summarize habitat conditions in the Naches River given the length of the river (45 miles). Generally, the upper 27 miles (above the Tieton River confluence) flows through forested lands of mixed ownership. About 25% of the river's floodplain is on National Forest land, 25% is state owned land, and 50% of the Naches River floodplain is privately owned. There is also considerable recreational access and use. State Route (SR) 410 runs adjacent to the river for the entire length of this segment. The floodplain is constricted and riparian vegetation has been lost due to the highway and rip-rap structures for home protection. Below the Tieton River confluence land use along the Naches River converts to predominantly agricultural (orchards, irrigated pasture, and hay production) and there are numerous water diversions. U.S. Highway 12 runs adjacent to the river from the Tieton River confluence downstream to the mouth impairing floodplain function. Haring (2001[1]) described numerous positive habitat attributes such as good riparian condition (in the upper portion of the river), good pool frequency and depth, good LWD and substantial amounts of off-channel habitat. These positive attributes combined with the length of river available for bull trout habitation suggest that FMO habitat conditions in the mainstem Naches River may not be limiting population productivity for Naches River fluvial bull trout populations.
Tieton River FMO Habitat
The significance of the Tieton River as FMO habitat for the Naches River fluvial populations is unknown. However, adult bull trout have been captured in the Tieton River (in the stilling basin directly below Tieton Dam) that were genetically assigned to the Rattlesnake Creek and American River populations (Small et al. 2009[2]). The Tieton River flows for 21.5 miles from the base of the dam to its confluence with the Naches River. U.S. Highway 12 parallels the river on the left bank for much of this length, which has altered the riparian corridor. However, this road has little effect on floodplain function as the river is naturally confined in this section. Other roads, structures, several developed campgrounds, and the Yakima-Tieton diversion dam contribute to the rivers disturbed condition. The channel is in poor condition due to structural restrictions and an almost complete absence of LWD (Haring 2001[1]). The most significant negative impact on fish habitat in the Tieton River is the regulated flow regime, which also contributes to the lack of LWD and channel complexity. The timing and magnitude of stream discharge in the river is the most highly altered of any in the Yakima Basin. Winter flows are 60-80% less than would occur under unregulated conditions and flow variability is extremely low. At a time when overwintering bull trout would be seeking pool habitat with cover, relatively none exists. During the first week of September an extreme, managed hydrologic event (“flip-flop”) occurs when dam releases are rapidly increased and average river flows often exceed by an order of magnitude what would be a natural base flow, sometimes exceeding 2,000 cfs. This condition persists to varying degrees for over a month.
Threats - NEED GROUP INPUT
Connectivity
Fish Passage Barriers
Threat Severity: Unknown, likely insignificant
Bull trout populations using Naches River as FMO habitat are not limited by natural barriers within the FMO habitat. Tieton and Bumping dams reduce metapopulation dynamics and gene flow. Nelson dam, a fish passage barrier on the mainstem Naches River near the Yakima River confluence was removed in 2023.
Low flows in parts of the Naches River during late summer may impact connectivity, however, bull trout intending to spawn usually migrate to their spawning grounds in June and July when flows are more adequate.
The Wapatox Diversion is located in the lower reach of the Naches River (headgates at RM 17). In a 2010 radio telemetry study, 13 bull trout were captured from the pool below the dam in the month of April (Mizell and Anderson 2010[3]). Telemetry showed bull trout were able to move upstream of the diversion, but the fact that so many bull trout were captured there indicates there may be some effect of the dam on natural movements by bull trout. However, the report also notes that the Wapatox pool might be attractive to bull trout due to it being a thermal refuge / "prey highway". This area should be reassessed to determine any impacts to connectivity.
Entrainment
Threat Severity: Unknown, likely insignificant
Several diversions exist along the Naches river. USBR biologists checked behind the screens of Wapatox Dam from ~2002-2009 and never found an entrained bull trout, but did find one bull trout trapped upstream of the screen that did not make it out of the bypass before the canal got shut off at the end of the season (Scott Kline, personal comm).
Dewatering due to flow management
Threat Severity: Insignificant
Naches River FMO habitat is not known to dewater.
Other
Land-use Issues
Forestry
Threat Severity: Unknown
There has been some timber harvest in the Naches River watershed over the past 35 years (Figure 1). The harvest has primarily occurred upland of the river and away from known spawning tributaries, but there may be some impacts to FMO habitat, like increased sedimentation from erosion and roads, and reduced recruitment of large wood to the river. Those impacts are unquantified.
Agriculture and Grazing
Threat Severity: Insignificant
Minimal livestock grazing occurs along the Naches River. Habitat degradation significant at the reach scale is not believed to occur, as federal livestock allotments are focused in the uplands, away from the highway. About 50% of the grazing allotments in the Naches Watershed are for sheep, which are moved constantly by shepherds and should have minimal impact to the riparian areas. However, the Nile and Rattlesnake Creek allotments are proposed to change to cattle to protect native bighorn sheep populations. The Okanogan-Wenatchee National Forest has been working on an updated environmental impact statement (2025) for these grazing allotments, which has included input from members of the Yakima Bull Trout Working Group in an attempt to minimize any negative effects to bull trout.
Recreation
Threat Severity: Unknown, likely significant.
Recreational impacts to bull trout in Naches River FMO habitat are not quantified but are likely to be a threat. There has been riparian and aquatic habitat degradation due to recreation, including heavy use of established and dispersed camping sites and day use areas. When fires are allowed, campers remove and burn downed wood that may otherwise be recruited to the river. Rock dams are a persistent issue, but few are channel spanning. Pollution including trash, human waste, and road run-off may be impacting water quality.
There is heavy recreational use in the Little Naches drainage, including 18 miles of jeep trails and many more miles of motocross trails, which may increase sedimentation and down-stream impacts in Naches FMO habitat.
There have been no reports of non-angling harassment of bull trout, but due to proximity of camp sites to the river and bull trout's large size fish may be harassed.
Roads and Development
Threat Severity: Unknown
Residential development is present in FMO habitat and may cause an incremental degree of degradation from loss of floodplain connection and riparian vegetation clearing near homes. Considering the large extent of FMO habitat, there is still sufficient habitat for bull trout. The Naches River floodplain is restricted due to highway 410 and heavy development and levees near the City of Naches. Agricultural land flanks the river downstream of Naches. High road density in Little Naches (2.5 miles / sq mile) and many stream adjacent roads have increased the drainage channel network by 30 percent, which likely causes the watershed to shed flows more efficiently, and decrease water storage function. Fine sediment monitoring by Yakama Nation indicates Little Naches watershed is properly functioning. Overall road density in the Naches Ranger district is high, although impacts to FMO habitat are unknown.
Mining
Threat Severity: Insignificant
Potential threats to FMO habitat were significantly diminished in 2020 when Washington State passed a ban on suction dredge mining in critical habitat for ESA listed species including bull trout. There is no known mining occurring in FMO habitat.
Other
Ecological Interactions
Brook Trout
Threat Severity: Unknown
Brook trout are present in the Naches River but no hybrids have been identified through genetics analyses. The significance of the threat is unknown.
Other Invasive Species
Threat Severity: Insignificant
There have been no observations of other invasive species.
Diminished Prey Base
Threat Severity: Unknown, likely significant
Anadromous fish runs are severely depleted from historic levels. Juvenile anadromous salmonid prey is scarce or not available. Dearth of anadromous carcasses deprives streams of marine-derived nutrients that likely drive invertebrate productivity. Impact is unknown but could be significant.
Disease
Threat Severity: Unknown
There have been no observations of disease in adult bull trout that utilize Naches FMO habitat. There is some concern about disease in Deep Creek after several bull trout juveniles have been observed with odd pigmentation patterns. No pathology has been completed. Deep Creek and Bumping Lake are headwaters to the Naches River.
Water Quantity and Quality
Flow issues/dewatering
Threat Severity: Unknown, likely insignificant
Altered flows in FMO habitat are the result of reservoir releases from Bumping and Tieton Dams. Impacts associated with this mechanism are unknown but believed to be insignificant. There are high flows in lower Naches during flip-flop but pre-spawn bull trout are well upstream by the time they occur.
Natural peak flows are occurring earlier than historical flow records by about one month (Gary Torretta, personal comm). This creates a longer period of base flow conditions subject to warming from summer and fall temperatures. Water quality might be diminished during low flows as well. This trend is clearly seen in most years in Little Naches and American Rivers, and in Naches River above the Tieton River.
Current and modeled future temperature conditions
Threat Severity: Unknown, likely significant
The mean August temperatures in the Naches River were predicted to be between 16-23°C according to the 2011 NorWest model. A dataset containing 236 water temperature observations between 2019 and 2024 showed a mean temperature range between 11°C - 18°C from the months of June through September (WDFW, Ecological Interaction Team). Samples ranged from the mouth of the Naches River up to the confluence with the Little Naches River. Many bull trout are known to skip spawning in some years (Fraley and Shepard 1989[4], Benjamin et al. 2020[5]), so they likely stay in FMO habitat if it is suitable. Temperature in parts of the mainstem Naches River is increasingly unsuitable during the summer and fall.
Other changes in hydrology
Fisheries Impacts
Angling Regulations/Fisheries Use/Poaching (Recreational)
Threat Severity: Unknown, likely significant
Legal angling for other species occurs in the American and Naches rivers. The Naches River is a popular fly fishing destination for people all around WA. Illegal angling for bull trout, or unintentional bull trout mortality may also occur. The impact from incidental or targeted takes is unknown but could be moderately significant. An angler was cited by WDFW enforcement in October 2024 for retaining a bull trout in the Naches River (WDFW Law Enforcement, Personal Comm.)
Management/Monitoring (Research)
Threat Severity: Insignificant
The WDFW Ecological Interactions Team visits a large number of sites in the Naches watershed each year. Their goal is to understand anadromous productivity throughout the Yakima River Basin. Their target species is O. Mykiss but they do encounter around 10 juvenile - subadult bull trout per year in their sampling efforts, primarily in the Naches headwaters (American River, Crow and Rattlesnake creeks) (Gabe Temple, personal comm.). Non-O.Mykiss species are usually not netted and the crew will move to a different part of the stream as to not disturb them. They do not collect biodata on bull trout, aside from a few years around 2015 where USFWS was directing the team to PIT tag any bull trout.
Other Threats
Low Population Resiliency
Climate Change
Wildfire impacts (sedimentation, increased water temperature)
Other
Summary of Primary Limiting Factors and Threats
The primary limiting factors and threats facing bull trout in the Naches River FMO habitat are likely recreation, diminished prey base, angling, and water temperature. The summer season brings heavy recreational use to the Naches Ranger District. Riverside camping and heavy day use contributes to riparian vegetation loss, rock dam construction, and pollution in the floodplain. Anadromous fish runs are depressed compared to the historical numbers, leading to reduced prey base for sub-adult and adult bull trout. Lack of marine derived nutrients may also contribute to reduced prey base. Finally, climate change effects like low-snowpack and hot, dry summers are contributing to unsuitable water temperatures and low flows in the mainstem Naches river, primarily during the months of August and September. Although spawning fish are likely in colder tributaries at this time, 30-50% of female bull trout are known to skip spawning in some years (Fraley and Shepard 1989[4]) and may not migrate at all (Benjamin et al 2020[5]). The impacts of angling on bull trout in Naches River FMO habitat are unquantified but illegal harvest of bull trout in the Naches River has been documented by WDFW law enforcement on several occasions.
Lack of fish passage at Tieton and Bumping dams is a threat to metapopulation dynamics and gene flow.
Forestry, grazing, and roads are likely lower-level threats that should be quantified. Brook Trout are present in Naches FMO habitat but have not been observed in Rattlesnake or Crow Creek spawning areas. They have been observed spawning in the same area as bull trout on the American River which indicates potential hybridization is occurring.
Recovery Strategy
FMO Habitat Recovery Strategy
Naches River FMO habitat would benefit from riparian restoration and floodplain connection to increase shade and available habitat for all salmonids. Restoring salmon and steelhead habitat would increase anadromous fish runs to provide marine nutrients to the ecosystem and prey for bull trout. Education and outreach to recreationists and anglers should be a priority, emphasizing leave-no-trace principles, fishing regulations and fish identification. Managers should consider an angler survey to quantify bull trout catch. Water quality in the Naches River should be monitored including water temperature and sediment load. Studies should be done to investigate the distribution of brook trout and introgression with the Naches bull trout populations.
Monitoring Needs/Key Questions
Brook Trout distribution in the watershed
Bull trout spawning outside regular indexes
Sedimentation due to roads, wildfire impacts
Actions
Future link/ iframe to PowerApp will go in this section.
Completed Bull Trout Recovery Actions
Naches FMO Action #4: Provide Passage at Nelson Dam
Recommended Actions
Basin-wide Action #1: Restore Healthy Salmon Populations
Basin-wide Action #2: Evaluate Climate Change Impacts
Basin-wide Action #4: Monitor Yakima Basin Bull Trout Genetics Over Time
Basin-wide Action #5: Nutrient Enhancement
Basin-wide Action #6: Outreach and Conservation
Basin-wide Action #7: Redd Surveys
Basin-wide Action #9: Habitat Monitoring
Naches FMO Actions
Naches FMO Action #1: Evaluate and Reduce Entrainment at Tieton Dam
Naches FMO Action #2: Evaluate Flow Management Improvements for the Naches
Naches FMO Action #3: Support Ongoing Habitat Restoration and Protection
Naches FMO Action #5: Conduct eDNA Assessment to Determine Occupancy and Distribution
Actions in the Yakima Steelhead Recovery Plan that benefit this habitat
Naches Action #5: Restore lower Naches River floodplain
Naches Action #7: Protect habitats in Naches River mainstem above Tieton Confluence
Naches Action #8: Maintain, upgrade or abandon forest roads
Naches Action #9: Provide passage at Bumping Dam
Naches Action #10: Improve habitat in lower Bumping
Naches Action #11: Restore side channels and floodplain of Little Naches River
Naches Action #12: Place large woody debris in Little Naches (as of 2025, approximately 2000 logs/trees have been placed in the mainstem LNR, Quartz Creek and Crow Creek).
Naches Action #13: Reduce dispersed recreation impacts in key tributaries
Naches Action #17: Increase instream flows in lower Rattlesnake Creek
Naches Action #18 Improve sediment transport at Rattlesnake Creek/Naches River confluence
Update Notes
2012 BTAP text copied into Yakipedia and edited to match new format in February 2025 by Aimee Taylor. ADD LINK TO 2012 BTAP pdf placemark
Additional edits proposed by Alex Conley, Aimee Taylor and Naches bull trout populations small group. Reviewed, and updated and approved by BTWG in XXXXXXXXXXXXX
Specific detail on out of cycle updates:
References-
- ↑ 1.0 1.1 Haring, Don. Habitat Limiting Factors Yakima River Watershed, Water Resource Inventory Areas 37-39 : Final Report. Washington State Conservation Commission, Dec. 2001, p. 364, https://ybfwrb.org/wp-content/uploads/2017/10/Haring-2001.pdf.
- ↑ Small, M. P., et al. WDFW Yakima Bull Trout Report. Phase 3: Genetic Analysis of Yakima Basin Bull Trout (Salvelinus Confluentus). Washington Department of Fish and Wildlife, 2009, https://ybfwrb.org/wp-content/uploads/2017/10/Small_et_al_2009.doc.
- ↑ Mizell, M., and E. Anderson. Summary of Bull Trout Tagged under the USFWS Funded Radio Telemetry Project in the Yakima Basin. Washington Department of Fish and Wildlife, 2010, https://ybfwrb.org/wp-content/uploads/2017/10/Mizell_Anderson_2010_appendices.pdf.
- ↑ 4.0 4.1 Fraley, John J., and Bradley B. Shepard. “Life History, Ecology and Population Status of Migratory Bull Trout (Salvelinus Confluentus) in the Flathead Lake and River System.” Northwest Science, vol. 63, no. 4, 1989, pp. 133–43.
- ↑ 5.0 5.1 Benjamin, Joseph R., et al. “Thermal Heterogeneity, Migration, and Consequences for Spawning Potential of Female Bull Trout in a River-Reservoir System.” Ecology and Evolution, vol. 10, 2020, pp. 4128–42.