Deep Creek Bull Trout Population

Overview

Deep Creek is the larger of two main tributaries to Bumping Reservoir. Deep Creek originates in the William O. Douglas Wilderness Area and the reach accessible to migratory fish is entirely within the Okanogan-Wenatchee National Forest. There is a 34 foot waterfall around 5.6 miles upstream of the confluence with Bumping Reservoir, which is the upstream extent of the adfluvial population. Downstream of the falls, it is not uncommon for the creek to experience severely diminished flows and/or complete dewatering in some reaches. Dewatering is occurring more frequently and for extended periods of time. The only significant tributary in the reach below the barrier waterfall is Copper Creek, which enters at about the halfway point (RM 2.9). Deep Creek is closed to angling year-round to protect bull trout.

Population Information

Population Distribution and Life History

Deep Creek supports a single local population of bull trout, which displays an adfluvial life history type. The spawning and rearing area for the population extends from the mouth to the waterfall with some limited spawning also taking place in the lower portion (~0.25 mile) of Copper Creek. (A bedrock cascade directly above this point is believed to be impassable.) Bumping Reservoir and the upper Bumping River provide FMO habitat for subadult and adult fish (BUMPING/DEEP CREEK MAP). Adult bull trout generally enter Deep Creek in late July to mid-August.

As mentioned above, Deep Creek adults occasionally stray into the upper Bumping River to spawn. A few bull trout redds have been observed in the upper Bumping over the years and juveniles have been observed during snorkel surveys. Genetic samples analyzed from 30+ juveniles collected in 2002 and 2010 revealed that these fish were not genetically distinct from Deep Creek bull trout (citation). These data support the hypothesis that adults spawning in the upper Bumping River are strays from Deep Creek and indicate that the stream does not support a separate, genetically distinct population.

Natural Barriers limiting distribution

A waterfall that is a complete barrier to upstream migration exists approximately 5.6 miles above the lake at 46.7894900, -121.3281894. (ADD PHOTO)

Population Genetics

Results of genetic analyses show this population is genetically distinct from all other populations in the Yakima Basin (Reiss 2003; Small et al. 2009). Genetic samples for the baseline were collected from post-spawn adults during a tagging study begun in 1997 (James 2002a). Interestingly, this population had a lower level of genetic diversity than would be expected based on abundance estimates. It may have experienced a genetic bottleneck when rotenone was applied to Bumping Reservoir in 1950 to eliminate suckers (Catostomus spp.) and Northern pikeminnow (WDFW 1991). Connectivity and thus the potential for genetic exchange with downstream populations in the Naches River fluvial system was eliminated by the construction of Bumping Dam in 1910.

Population Monitoring

After the 1950 rotenone application, Dolly Varden (i.e., bull trout) began to show up in WDFW creel surveys in 1953 and continued to do so until legal angling for the species was prohibited in the 1990s (WDFW file data). The first official monitoring of Bumping Reservoir’s fish assemblage appears to have been done by Mongillo and Faulconer (1982) who gillnetted the lake and captured five bull trout. A number of other salmonid species were also captured including brook trout, which continue to maintain a presence in the reservoir and stream. Exploratory spawning surveys were begun in Deep Creek in 1989 with complete surveys conducted annually since 1991.

The first Deep Creek genetic samples were collected from juvenile bull trout in 1997 with the subsequent analysis reported by Reiss (2003). James (2002a) trapped and tagged adult bull trout in Deep Creek from 1997 through 2000 while studying the population status and life history characteristics of the population. In 2000, snorkel surveys were conducted in the creek to determine the migration timing of pre-spawn adults. WDFW snorkeled and electroshocked Deep Creek in 2003 as part of a project to develop a bull trout presence/absence sampling protocol (Hoffman et al. 2005). Larsen et al. (2003) continued the development of protocols, using data from streams across Washington. Peterson et al. (2005) also used these data in an attempt to understand if block nets are necessary to keep fish from fleeing the area during snorkel and electrofishing surveys.

Seventeen post-spawn bull trout were captured in 2005 and implanted with radio tags to track their movements after they returned to Bumping Reservoir (Mizell and Anderson 2008). Included in these were five implanted with archival tags to monitor preferred water temperatures and depths, but only two of these tags were recovered. All 17 of the tagged bull trout remained in Bumping Reservoir, which was of interest because, as is the case for the other storage dams in the Yakima Basin, the outlet works of Bumping Dam are unscreened.

The upper Bumping River has also received monitoring attention. Beginning in 1999, sporadic snorkel surveys have been conducted in the stream. No bull trout were observed by Craig (Craig 1999). Subsequent snorkel surveys (2002, 2003, and 2010) documented the presence of bull trout juveniles although not in large numbers (Reiss 2011). Exploratory spawning surveys, also sporadic, have resulted in one bull trout redd observed in 1994 and two in 2009 (Reiss 2011). In six other years none were found and none of the fish tracked by Mizell and Anderson (2008) entered the upper Bumping River.

It is possible for Deep Creek bull trout to become displaced downstream if entrained through the unscreened outlet works of Bumping Dam. About a half-mile of the Bumping River below the dam was snorkeled in 2001 and six bull trout, all greater than 12 inches in total length, were observed (Kalin and Ackerman 2002). However, none of these fish were confirmed to have originated in Bumping Reservoir. Fluvial bull trout from the Naches River populations will use the Bumping River as FMO habitat (Mizell and Anderson 2008).

Redd Surveys

The spawning period for the Deep Creek population begins earlier than any other local population in the Yakima Basin. Spawning begins in late August is usually completed by mid-September. Complete bull trout redd surveys have been conducted on Deep Creek since 1991. These surveys cover the entire length of the mainstem spawning area (see above) and approximately the lower quarter-mile of Copper Creek.

Other Distribution Data (eDNA, etc.)

ANYONE KNOW OF ANY SURVEYS DONE ABOVE THE FALLS? ANY CHANCE OF RESIDENT POPULATION?

Population Status and Trend

The USFWS (1998) considered the Deep Creek population to be depressed, decreasing, and at risk of stochastic extirpation. The WDFW rates the status of this stock as depressed (WDFW 2004). When the 2012 Bull Trout Action Plan was written, the authors suggested that both of these ratings warrant reconsideration, however as of 2025 the population is declining again.

Deep Creek Redd Counts Through 2024

Redd counts over the period of record have been highly variable. Between 2006 and 2012, there was a steadily increasing trend where the previous long term average of 84 redds more than doubled to 169. Over 190 redds were observed in 2010 and 2011 (INSERT REDD SURVEY GRAPH). After high levels of spawning in 2010 and 2011, the redd counts decreased to 22 redds in 2015, the lowest count since 1994. 2015 was an extreme drought year in the Yakima River Basin. Redd counts slowly climbed again to around the long-term average of 90 redds. In 2024 counts decreased again.

An extrapolation from the data is the effect dry years, and thus the occurrence of reach dewatering, have on this population’s reproductive success. The effect is evident in the redd counts obtained during particularly dry years (e.g., 1993, 1994, 1996, 2001, 2003, and 2005, 2015, and 2024) when the number of redds observed ranged from 12 to 73. In contrast, 2007-2012 were good-to-excellent water years in the Yakima Basin. The timing and extent of dewatering in drought years seems to be increasing, which prohibits fish passage to the upper part of stream, strands and kills juvenile bull trout, and limits overall available spawning habitat by close to 50%.

Habitat

Habitat Overview

Deep Creek ranges in elevation from 3,435 feet at its mouth to 3,840 feet at the barrier waterfall. This reach is entirely within the National Forest with the primary land use being recreation, mostly hiking and horseback riding. There are numerous dispersed campsites in the drainage. These are close to the two roads in the watershed but only a couple of them are close to the creek’s banks; most are located on elevated terraces well away from the channel. One of the two roads (FS 1800) is not near Deep Creek until it crosses it about a mile above Bumping Reservoir. A new bridge was constructed in 2011 to replace two perched culverts that were a barrier to juvenile fish passage under certain flow conditions. There were also habitat impacts from dispersed camping at this site. The passage problem has been remedied; it remains to be seen if the camping impact resurfaces but for the time being the area has been restored. The other road (FS 1808) runs adjacent but not in close proximity to Deep Creek for several miles. This road used to cross the stream over a problematic undersized culvert about a half-mile below the upstream barrier before a flood in 2006 washed it out. A new bridge was constructed at this site in 2011 and the road continues on the other side of the creek. Overall, habitat conditions in Deep Creek are good to excellent for all rating parameters. There is abundant LWD, a low percentage of fine sediments, abundant spawning gravels, a healthy riparian corridor, and excellent water quality (USFS 2006a). Although technically Deep Creek did not meet Forest Plan standards for pool frequency, the percentage of the stream classified as pool habitat was large (44%) so this standard is somewhat deceiving.

Undoubtedly the most significant habitat issue in Deep Creek is the dewatering mentioned in the paragraph introducing this population. Between the FS 1800 bridge (RM 0.9) and the Copper Creek confluence (RM 2.6), it is not uncommon, even in years that are just moderately dry, for a portion of Deep Creek to experience severely diminished flows and/or complete dewatering during the late summer. The dewatering is typically first observed about a half-mile above the bridge and can extend as much as a half-mile upstream, often continuous. This is a low-energy reach with a broad floodplain to the east. The west side of the valley is controlled by a steep talus slope preventing the lateral movement of the stream and contributing loose unarmored substrate. Subsurface flow appears to move laterally to the east; just downstream of the area an extensive side-channel complex occurs in thick forest. This complex is heavily utilized by spawning bull trout.

FMO habitat for the Deep Creek bull trout population is in Bumping Reservoir. Neither the sparse shoreline development or water sports activities on the lake are believed to influence habitat quality. Bumping Reservoir is the smallest storage reservoir in the Yakima Basin and does experience extreme drawdown in the summer (avg. 80%). A 14,000 acre-foot conservation pool (i.e., dead storage), however, cannot be accessed. As a result, Bumping Reservoir, which has the highest refill ratio in the basin, recovers quickly when irrigation releases cease. The effects of reservoir depletion on FMO habitat quality and quantity are unknown but not believed to be significant.

Habitat Monitoring

Flooding in 2006 damaged Forest Service Roads 1800 and 1808 where Deep Creek flowed through culverts. Both culverts were considered impediments to upstream passage of juvenile fish at some flows although adults passed upstream through both culverts. A number of documents and emails have been written regarding the replacement/repair of these culverts and roads (Gonzales 2007; Krupka 2007; McCoy 2008). Both culverts were replaced with bridges in 2011.

Banish (2003) measured bull trout microhabitat and mesohabitat in 10 Eastern Washington and Oregon streams. He conducted day and night snorkeling in Copper Creek, a tributary of Deep Creek. He pooled his data, however, and did not report results for individual steams.

USBR examined Bumping Reservoir limnology from 1998-2001, and data are reported in Ackerman et al (2002). Lieberman and Grabowski (2007) conducted limnological studies in Bumping Reservoir from 2003-2005. They concluded that zooplankton densities may limit the lake’s capacity to support resident fish as well as introduced salmonids and suggested the nutrient enrichment may be one method to increase both algal and zooplankton production.

The Forest Service completed habitat surveys on Deep Creek in 1993 (4.9 miles) and again in 2005 using Hankin and Reeves protocol (Hankin and Reeves 1988; USFS 2006a). The upper Bumping River was surveyed in 1994-95 (9.5 miles) and 2003 (10.0 miles) (USFS 2003a). In all of these surveys, data was collected on pool/riffle frequency, riparian and channel condition, substrate, LWD, and temperature.

Deep Creek at the 1800 Road crossing was monitored for temperature via thermographs deployed during the summer low flow period in 9 out of 10 years from 1996-2005 (USFS 2011a). A thermograph was deployed on the upper Bumping River in 1996 and again from 2000-2004. Temperature data since 2005 is a monitoring gap.

Threats

Connectivity

Fish Passage Barriers

Threat Severity:

Entrainment

Threat Severity:

Dewatering due to flow management

Threat Severity:

Land-use Issues

Forestry

Threat Severity:

Agriculture and Grazing

Threat Severity:

Recreation

Threat Severity:

Roads and Development

Threat Severity:

Mining

Threat Severity:

Ecological Interactions

Brook Trout

Threat Severity:

Other Invasive Species

Threat Severity:

Diminished Prey Base

Threat Severity:

Disease

Threat Severity:

Water Quantity and Quality

Flow issues/dewatering

Threat Severity:

Current and modeled future temperature conditions

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Fisheries Impacts

Angling Regulations/Fisheries Use/Poaching (Recreational)

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Management/Monitoring (Research)

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Other Threats

Low Population Resiliency

Climate Change

Summary of Primary Limiting Factors and Threats

The highest severity threat to the Deep Creek population is Bumping Dam, which is a complete barrier to passage and isolates this population from the Naches River fluvial populations. Entrainment through the dam may also reduce population productivity, as individuals are lost from the population. Other threats to this population include illegal angling in Bumping Reservoir, dewatering in spawning and rearing reaches, introgression with brook trout, and lack of anadromous prey base and marine derived nutrients. A potential threat that is not rated here, but could have a very significant impact on this population, is the proposal in the Yakima Basin Integrated Water Resource Plan (Ecology 2012) to expand the storage capacity of Bumping Reservoir. This would elevate the threat of limited habitat by inundating .75 miles of spawning and rearing habitat and also potentially exacerbate the effect of dewatering.

While forest management issues, the potential for low abundance (large annual fluctuations in abundance), and recreation are all present in the population area, they are not considered significant threats. Agriculture, altered flows, development, grazing, limited extent of habitat, transportation issues, and mining are not present in this population area.

Recovery Strategy

Population-level Recovery Strategy

This population has been identified as a “Protection” population with a priority for continuation of population monitoring but with limited restoration actions recommended. The highest priority action is Passage at Bumping Dam. Bumping Reservoir is a popular fishing location; a priority recommended action is outreach to educate anglers and recreationists. Brook trout introgression has been documented in this population and should be monitored with future genetic sampling, but no specific brook trout removal actions are recommended at this time. Implementing carcass analog placement to address lack of marine derived nutrients will likely only happen after a successful pilot study is implemented elsewhere in the basin and is deemed necessary. Bumping Reservoir contains a healthy population of reproducing kokanee salmon providing an abundant food source for Deep Creek bull trout. There is currently a proposal to expand the capacity of Bumping Reservoir by 170 acre-feet, which would inundate the lower portion of Deep Creek. It will be critical to ensure that the proposed reservoir expansion does not compromise the viability of the Deep Creek population.

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Actions

Future link/ iframe to PowerApp will go in this section.

Completed Bull Trout Recovery Actions

• Culverts (partial passage barriers) on forest roads 1800 and 1808 were replaced with bridges in 2011.
• Fishing regulations have been implemented to protect bull trout in Deep Creek (see Appendix F).

Recommended Actions

Relevant Multiple Population Actions

• Multiple Populations #1: Outreach on bull trout conservation issues (landowners, recreationists, anglers, school groups, and others).
• Multiple Populations #5: Carcass analog placement if pilot studies demonstrate success.
• Multiple Populations #9: Periodic entrainment studies at storage dams.
  • Multiple Populations #2: Continue redd surveys within the established index areas to monitor long-term abundance trends.
    • Multiple Populations #3: Continue temperature monitoring in Deep Creek.
      • Multiple Populations #7: Continue to screen all collected genetic samples for evidence of genetic introgression with brook trout.

XXXXXXXX River Actions

Ensure impacts to bull trout from the proposed reservoir enlargement are minimized.

Actions in the Yakima Steelhead Recovery Plan that benefit this population

None

Update Notes

2012 BTAP text copied into Yakipedia and edited to match new format inXXXXXX by Aimee Taylor. ADD LINK TO 2012 BTAP pdf placemark

Additional edits proposed by Alex Conley, Aimee Taylor and XXXXXXX small group. Reviewed, and updated and approved by BTWG in XXXXXXXXXXXXX

Specific detail on out of cycle updates: