Prepared by: Siskiyou Research Group P.O. Box 2550 Cave Junction, OR For Public Review

Transcription

1 Prospect No. 3 Hydroelectric Project FERC Project No. P-2337 Initial Study Report: Fish Habitat (South Fork Rogue River 2014 Level II Stream Survey Report) May 2015 Prepared by: Siskiyou Research Group P.O. Box 2550 Cave Junction, OR For Public Review

2 SOUTH FORK ROGUE RIVER 2014 LEVEL II STREAM SURVEY REPORT PREPARED FOR: PACIFICORP, HYDRO RESOURCES MEDFORD, OREGON PREPARED BY: SISKIYOU RESEARCH GROUP POST OFFICE BOX 2550 CAVE JUNCTION, OREGON (541)

3 SOUTH FORK ROGUE RIVER 2014 LEVEL II STREAM SURVEY REPORT Submitted to: PACIFICORP, HYDRO RESOURCES MEDFORD, OREGON March 2015 Prepared by: SISKIYOU RESEARCH GROUP Post Office Box 2550 Cave Junction, Oregon (541)

4 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 Table of Contents Executive Summary.. 1 Introduction 5 Geology/Geomorphology.. 9 Riparian Habitat Aquatic Habitat Fisheries. 12 Affected Waters. 13 Previous Studies. 13 Imnaha Creek 15 Reach Summaries Reach Geomorphology/Hydrology Riparian Habitat Aquatic Habitat Fisheries Reach Geomorphology/Hydrology Riparian Habitat Aquatic Habitat Fisheries Reach Geomorphology/Hydrology Riparian Habitat Aquatic Habitat Fisheries Reach Reach Geomorphology/Hydrology Riparian Habitat Aquatic Habitat Fisheries Tributaries Summary.. 39 References. 41 i

5 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 Table of Contents Tables Table 1. Summary of Stream Attributes by Reach 8 Table 2. Summary of Fish Species, Size Class, and Abundance.. 23 Table 3. Summary of Tributary Information. 38 Appendices: Appendix A (Explanation of Codes) Appendix B (Stream Survey Maps) Appendix C (Stream Survey Data Calculation Tables) Appendix D (Wolman Graphs) Appendix E (Survey Field Data Forms and Field Comments) Appendix F (Photographic Log and Photographs) Information Block Stream Name: South Fork Rogue River Tributary to: Rogue River at Lost Creek Lake Reservoir Stream Order 4 Start Location: 042 o N, 122 o W Distance Surveyed: 13.3 miles USGS Quadrangle: Prospect South County, State: Jackson, Oregon NFS Watershed Code: 17,10,03,07,02,07 Surveyors: G. Bennett, J. Rohde, L. Limburg ii

6 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 EXECUTIVE SUMMARY In August 2014 Siskiyou Research Group (SRG) conducted an aquatic habitat inventory and an aquatic biota survey of the South Fork Rogue River pursuant to the requirements of the Stream Inventory Study (Section 4.1) of the revised Fish Community and Habitat Study Plans (Study Plan) for the Prospect No.3 Hydroelectric Project (FERC Project No. P-2337). SRG followed methods described in the Forest Service Region 6 (Pacific Northwest Region) Stream Inventory Handbook (2014). The survey began approximately 500 feet upstream of the South Fork Rogue River s confluence with the Middle Fork Rogue River (42 o N, 122 o W, NAD 83) and extended upstream 13.3 miles (measured). The aquatic biota surveys were performed to determine fish species presence and distribution, relative abundance, and to correlate fish densities with habitat data at the reach scale. The Study Plan identified two study reaches on the South Fork Rogue River for aquatic habitat inventory and fish community surveys. The first study reach extends from the confluence of the South Fork Rogue River with the Middle Fork Rogue River (River Mile (RM) 4.5) upstream six miles to the South Fork Dam (RM 10.5). The second study reach extends 0.5 miles upstream of the South Fork Impoundment (RM 10.5 to RM 11.0). Within these two study reaches SRG identified five separate reaches in accordance with Stream Inventory Handbook guidelines, with each reach sharing relatively uniform physical attributes such as stream flow, stream gradient, habitat width, streambed substrate, and canyon morphology (Stream Inventory Handbook 2014). SRG identified three reaches in the six-mile segment downstream of the South Fork Dam (RM 4.5 to RM 10.5). A fourth reach was identified as the South Fork Impoundment, but no data was collected in this non-riverine feature (Stream Inventory Handbook 2014, page 22, paragraph 1). A fifth reach was located immediately upstream of the South Fork Impoundment. The lower three reaches (from Middle Fork confluence to the South Fork Dam) were surveyed to provide data on the river section directly affected by PacifiCorp's hydroelectric project, and the fifth reach, located immediately upstream of the project, was surveyed to provide aquatic habitat and fish population 1

7 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 information to fill a data gap and provide a basis for comparison with the project-affected waters (South Fork Bypass Reach). SRG deviated from the Study Plan s proposed survey segments by (1) not beginning the survey of the South Fork Rogue River at its immediate confluence with the Middle Fork Rogue River and (2) including aquatic and riparian habitat data and fish community data on 6.83 miles of stream above the South Fork Impoundment instead of 0.5 miles of stream above the Impoundment as proposed in the Study Plan. The survey began approximately 500' feet upstream of the South Fork Rogue River s confluence with the Middle Fork Rogue River due to poor access and unsafe conditions. Data was included for a reach of 6.83 miles upstream of the Impoundment because, in conjunction with the survey work performed for PacifiCorp, SRG was commissioned to survey the upper South Fork Rogue River, beginning immediately upstream of the South Fork Impoundment, for the Rogue River Siskiyou National Forest (RR-SNF) to partially satisfy their aquatic resource inventory goals. SRG used the same methods for both surveys and included the results from the survey work conducted upstream of the project area to provide a comprehensive description of the habitat conditions and fish community upstream of the South Fork Bypass Reach, and to provide a robust dataset for comparison with the project-affected reaches of the South Fork bypass reach. The geomorphology of Reach 1 through Reach 3 (RM 4.5 to RM 10.5) was characterized, with exception, by steeply sloped and deeply incised basalt canyons and bedrock gorges etched into a gently sloped landscape derived from volcanic deposition. The stream channel was stable and controlled by bedrock or colluvial boulders. Stream gradients averaged three percent to four percent, and aquatic habitats consisted of deepchanneled, boulder- and cobble-dominated rapids, deep plunge pools, scour pools, and bedrock trench pools. Channel substrate was dominated by coarse particles (large cobble and boulders) and lacked small sediment (sand, gravel, and small cobble). Stream and channel morphology was characterized by pool-drop sequence within a confined, low sinuosity channel. Large woody material (LWM) was not abundant in the lower section (seventeen pieces/mile to twenty-eight pieces/mile) and was influencing channel 2

8 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 morphology in very few places. Instream wood was found as scattered pieces and wood associated with logjams. All instream wood was naturally recruited. The geomorphology of Reach 5 (RM 10.5 to RM 17.3) was characterized by a gently to moderately sloped, V-shaped, colluvial canyon (Photo 69), and flat-floored, alluviated canyon (Photo 85). Map and field estimated valley widths ranged from eighty feet to greater than 200 feet, but generally valley widths were 100 to 200 feet. Stream gradients averaged one percent to two percent and the most common aquatic habitats were long rapids and riffles (Photo 70) and large mid-channel scour pools (Photo 86). Substrate estimates and Wolman Pebble counts indicated a gravel and cobble dominated channel with substantial amounts of sand in both fast water (rapids) and slow water (pools). LWM was moderately abundant in Reach 5 (sixty-eight pieces/mile) and was found as scattered pieces (Photo 75) and in large wood complexes (Photos 76, 89). These wood jams were influencing channel morphology by retaining large amounts of sediment (sand, gravel, and small cobble) and by creating and maintaining side channel habitat. The large wood jams observed in Reach 5 indicated a system that experiences occasional flooding from rain-on-snow as a result of a large portion of this watershed being located in the transient snow zone (elevation range 3,500 feet to 5,000 feet). Aquatic biota surveys were conducted with mask and snorkel and focused on the identification, distribution, and abundance of salmonids. SRG identified mostly rainbow trout (Oncorhynchus mykiss) in the size class of 100 mm to 200 mm. Also identified were cutthroat trout (Oncorhynchus clarkii) in Reach 1 and Reach 2, and eastern brook trout (Salvelinus fontinalis) in Reach 1 through Reach 5. Native non-salmonid fish identified were sculpin (Cottus spp). Amphibians observed included adult and larval stage tailed frogs (Ascaphus truei), red-legged frogs (Rana aurora), Cascades frogs (Rana cascadae), and Pacific giant salamanders (Dicamptodon tenebrosus). Resident trout densities ranged from fish/yd 2 (Reach 2) to fish/yd 2 (Reach 5). Fish densities were higher in the lower section (Reach 1 Reach 3, average = fish/yd 2 ) than were found in Reach 5 (0.036 fish/yd 2 ). Fish distribution extended through Reach 5. Three waterfalls were identified in Reach 1 ranging in height from four feet to ten feet. 3

9 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 The ten foot high waterfall (WF SO 50, Photo 16) was estimated to be an upstream fish passage barrier at low stream flows. Reach 3 ended at the South Fork Dam (ARTIF SO 301, Photo 60). This man-made concrete dam has been fitted with a fish passage facility that includes an 86-foot long, 15-pool concrete ladder for upstream passage, and a 0.25-inch wedge wire inclined-plane fish screen which transitions to a bypass pipe to return fish to the ladder for downstream passage around the dam. No fish passage barriers were observed in Reach 5. The riparian habitat and adjacent forest in the lower section (with the exception of upper Reach 3) was located on privately owned corporate timberland and consisted of early seral stands of Douglas-fir regenerating from past harvest. Specifically, the riparian vegetation consisted of an overstory of small tree class Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) as the primary overstory species. Understory species included willow (Salix spp), red alder (Alnus rubra), vine maple (Acer circinatum), bigleaf maple (Acer macrophyllum), Pacific madrone (Arbutus menziesii), and Pacific ninebark (Physocarpus capitatus). Small stands or pockets of mature Douglas-fir and western hemlock were observed in the inner riparian zone in areas that appeared difficult to access for timber harvesting. In some areas we observed the retention of a narrow strip of riparian vegetation buffering a recent clearcut of the outer riparian trees. The large amount of timber harvesting that has occurred within the riparian zone and in the adjacent forest has reduced the potential recruitment of LWM in the lower section. The riparian forest occupying Reach 5 is located on public land and is characterized as a mature mixed conifer forest consisting of large and mature seral class Douglas-fir, western hemlock, white fir (Abies concolor), mountain hemlock (Tsuga mertensiana), and Engelmann spruce (Picea engelmannii). Other riparian species observed in Reach 5 include Pacific yew (Taxus brevifolia), red alder, willow, vine maple, ponderosa pine (Pinus ponderosa), chinquapin (Chrysolepis chrysophylla), and western white pine (Pinus monticola). The large and mature class trees dominating the riparian zone contributed to the continuous and sustainable recruitment of instream LWM in Reach 5. 4

10 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 INTRODUCTION The South Fork Rogue River watershed drains the western slope of the southern Cascade Mountain Range between Crater Lake to the north and Mt McLoughlin to the south. The South Fork Rogue River begins in the high mountain lakes area of the Sky Lakes Wilderness and flows north for approximately eighteen miles to the National Forest boundary where it turns west and flows for approximately 5.5 miles across private land to its confluence with the Middle Fork Rogue River. The South Fork Rogue River continues west for approximately five miles where it joins the North Fork Rogue River at the head of Lost Creek Lake reservoir. The South Fork Rogue River is a fifth order stream that drains a watershed area of approximately 160, 773 acres and includes the subwatersheds of the Middle Fork Rogue River, Red Blanket Creek, Imnaha Creek, and Beaver Dam Creek. The portion of the South Fork Rogue River watershed concerned with this survey includes the subwatersheds upstream of the confluence with the Middle Fork Rogue River (i.e. Buck Creek, Imnaha Creek, Lodgepole Creek, Big Ben Creek, and upper South Fork Rogue River) encompassing an area of approximately 69,404 acres. The geomorphology of this area is a result of volcanism, precipitation patterns, glaciation, and erosion, and the geomorphologic features include alpine mountainous terrain (ancient volcanoes), basalt plateaus (lava flows), narrow basalt canyons and gorges (erosion), large forested flats (pumice deposits), and a wide flat-floored glacially carved alluviated valley with floodplains and side channels. Elevations in the South Fork Rogue River watershed range from approximately 2,140 feet at the survey start point near the confluence with the Middle Fork Rogue River to 7,474 feet atop Lucifer Mountain at the headwaters of Big Ben Creek. Approximately fourteen percent of the South Fork Rogue River watershed is located in the rain dominated elevation band (< 3,500 feet), thirty-five percent is located in the transient snow zone elevation band (3,500 feet 5,000 feet), and fifty-one percent is located in the snow zone (>5,000 feet). As a result bankfull indicators suggest a hydrologically stable channel with high water typically occurring during spring snow-melt runoff. However, with over one-third of the watershed area located in the transient snow zone, rain-onsnow events do occur and can generate flood level flows. Evidence of past high flows 5

11 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 was observed in the formation of large wood jams located in Reach 5. Cool moist winters and warm dry summers characterize the climate of the South Fork Rogue River watershed. Annual precipitation ranges from forty-five inches to sixty-five inches and is delivered typically from October through March. Landscape features of the South Fork Rogue River watershed include: Typical High Cascades character of craggy volcanic peaks and mountain lakes located in glacially carved basins. Developed and dispersed camping and trailheads that access the Sky Lakes Wilderness Area. Major source of cold water. National Forest land that provides habitat and connectivity for plants and animals. High density road system outside of the Wilderness Area that provides access to much of the watershed area. Clear, cold, spring fed systems that are nutrient poor with low densities of fish. Diversion dam and small impoundment located on South Fork Rogue River at the confluence with Imnaha Creek, used for hydroelectric power generation and operated by PacifiCorp. Lower portion of watershed is privately owned and managed extensively for timber, cattle, and agriculture. Mixed conifer forests dominated by Douglas-fir and white fir in the mid elevations, and Shasta Red fir and mountain hemlock dominated forests at the higher elevations. The majority of the South Fork Rogue River watershed is managed by the High Cascades Ranger District of the Rogue River-Siskiyou National Forest (RR-SNF) for Wilderness, Late Successional Reserves, and Riparian Reserves. Other management allocations include Big Game Winter Range Matrix and Timber Matrix. The western portion of the watershed is located entirely on privately owned corporate timberland used for timber production, livestock grazing, hunting, and access to public land. The middle and upper portion of the South Fork Rogue River watershed is located on public land, with the exception of one square mile section (section 16) in the Imnaha Creek drainage. In August 2014 approximately 13.3 miles of South Fork Rogue River were surveyed for type of aquatic habitats, composition of channel substrates, amount and distribution of 6

12 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 stream bank erosion, amount and distribution of large woody material (LWM), presence of invasive species, and composition of riparian habitat using a protocol described in the 2014 Forest Service Region 6 Stream Inventory Handbook. Additionally, we conducted fish surveys with mask and snorkel to assess species composition, abundance, and distribution. The survey of South Fork Rogue River was broken into five reaches based on changes in canyon morphology and stream flow. South Fork Impoundment was identified as a separate reach, Reach 4, but no data was collected (per Stream Inventory Handbook, 2014). Right and left stream bank designations were of the perspective of looking downstream. All aquatic habitats were measured for length, width, and depth (or height in the case of waterfalls). Table 1 summarizes information collected during the survey of South Fork Rogue River. This table also serves as a comparison of data between the four surveyed reaches. An explanation of codes used in this report is found in Appendix A. Survey maps showing the location of survey start and end points, reach breaks, SOs, tributaries, special case habitats, and photographic points are found in Appendix B. One hundred fifteen photographs were taken and described in a photographic log depicting representative/typical habitats, unusual or permanent features, landmarks, wood complexes, riparian forests, amphibians, and reach start and end habitats. Photographs and the photographic log are found in Appendix F. SRG is qualified to conduct this aquatic, riparian, and biotic survey work for PacifiCorp in partial fulfillment of FERC s Integrated Licensing Process. SRG has been conducting Level II Stream Inventory work since 1996 in Southern Oregon and Northern California using the same surveyors and following essentially the same methods. In this time SRG has conducted aquatic habitat and aquatic biota survey work on over one thousand miles of streams, largely in the Siskiyou and Cascades Mountain Ranges. SRG has attended several Stream Inventory Training sessions and has completed Stream Restoration courses with Portland State University s Environmental Professional Program. 7

13 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 Table 1. Summary of South Fork Rogue River Attributes Stream Survey. Reach Stream Order Rosgen Channel Type B B F B Valley Segment Bedrock Colluvial Colluvial Alluviated Type Canyon Canyon Canyon Canyon Valley Narrow Narrow Narrow Moderately wide Form Box and V-Shaped V-Shaped V-Shaped V-shaped/Flat-floored Valley Width Estimate (ft) Measured Length (miles) Mapped Gradient (%) Measured Sinuosity Entrenchment Ratio Bankfull Width:Depth Ave. Bankfull Width (ft) Ave. Bankfull Depth (ft) Ave. Floodprone Width (ft) Ave. Floodprone Depth (ft) Ave. FW Width (ft) Ave. FW Depth (ft) SW (area) :FW (area) SW Units / Mile Ave. Residual SW Depth (ft) % SW Units Bank Instability (% reach length) # Special Case Units Dominant / Subdominant Boulder / Boulder / Boulder / Gravel / Substrate Cobble Cobble Cobble Cobble D 50-1 (mm) D 84-1 (mm) > D 50-2 (mm) D 84-2 (mm) Dominant / Subdominant ST, SP / ST, SP / ST, SP / LT, MT / Riparian Veg. Class LT LT LT ST Overstory / Understory CD,CH / CD,CH / CD,CH / CD,CH Riparian Species HB,HA,HW HB,HA,HW HB,HA,HW HA,HW,CY,CH,HV SWM / Mile MWM / Mile LWM / Mile Hi/Lo H 2 O Temp. ( 0 C) 12/9 10/9 14/8 10/7 Dominant Cover Substrate Substrate Substrate, Depth Substrate, Depth Type for Fish Depth Depth LWM Fish Species ONMY, ONCL ONMY, ONCL ONMY, SAFO ONMY, ONCL Observed SAFO SAFO SAFO Salmonid Density (fish/yd 2 )

14 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 GEOLOGY / GEOMORPHOLOGY The South Fork Rogue River watershed is located in the geologically young High Cascades physiographic province. The watershed is located on the uppermost western flanks of the High Cascade Mountain Range and varies in age between 6,800 years to 8 million years old. The Cascade Mountain Range is a formation of volcanic mountains that stretch from northern California to southern British Columbia. To the west lies the older (10 million to 20 million years) Western Cascades physiographic province and to the east the fault block mountain and valley formations of the Basin and Range province. The watershed area contains numerous volcanic vents (i.e. Blue Rock, Smith Rock, Luther Mountain, Shale Butte) and associated valley-filling lava flows. Superimposed on this volcanic landscape are the effects of extensive glaciation and erosion. As recently as 15,000 years ago a continuous ice sheet covered the high Cascades from Mt. McLoughlin to Mt. Hood. Today, lower slopes and valleys are blanketed with thick deposits of glacial till scoured from the uplands. In the current climate regime, the relatively high rates of precipitation and abundant snowfall in the region have given rise to many streams. Water from snowmelt and rainfall percolates into the fractured volcanic deposits producing countless springs, which emerge on mountain slopes feeding streams with ground water. The South Fork Rogue River watershed is comprised of rock types from volcanic activity and deposits of crushed and pulverized rock by the mechanical actions of glaciation and erosion. Located in the South Fork Rogue River watershed are basalt and basaltic andesite, andesite, glacial till, alluvial deposits (mid-watershed along stream course), and small pockets of intrusive rock and volcanic sedimentary rock. Remnants of welded ashflow from the culminating eruption of Mt. Mazama (approximately 6,800 years ago) are present in the South Fork Rogue River watershed (Forks Watershed Analysis, 1998). 9

15 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 RIPARIAN HABITAT The riparian habitat, as defined by the 2014 Forest Service Region 6 Stream Inventory Handbook, consists of an area extending 100 linear feet out from each stream bank. This survey divided the riparian habitat into an inner zone (0-25 feet) and an outer zone ( feet). We reported the average vegetative condition regarding dominant species and size class in the overstory and understory at each snorkeled unit to help characterize the riparian forest. We also noted the general condition of riparian habitat throughout each reach with qualitative observations. The reach summaries contain descriptions of the riparian habitat for that reach. In general, the riparian vegetation found in the lower section of the South Fork Rogue River consisted of an early seral stage of small tree, sapling/pole, and shrub class vegetation as a result of timber harvesting. Small stands of mature forest remain in areas that were presumably difficult to access for harvest. The lack of a large and mature tree component in the riparian zone is partly responsible for a lack of instream LWM in the lower section. Conversely, the riparian vegetation in the upper section consisted of a mature mixed conifer forest providing a large recruitment potential of LWM and a moderately large amount of instream LWM. The survey photos found in Appendix F provide the best indication of the current condition of the riparian habitat. Canopy closure and riparian-provided shade to South Fork Rogue River were variable and influenced by the seral stage of the riparian vegetation, the width of the canyon and channel, and stream orientation. AQUATIC HABITAT The most common aquatic habitats observed in the lower section (Reach 1 Reach 3) were deep-channeled, large cobble- and boulder-dominated rapids, and large, deep, midchannel scour pools, plunge pools, and bedrock trench pools. Side channel habitat was recorded in upper Reach 1, throughout Reach 2, and a small amount in Reach 3. 10

16 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 Stream gradients, measured with an Abney hand level in fast water habitats 1, ranged from two percent to six percent in the lower section. Fast water habitat in the boulderdominated canyon of the lower section contained a large percent of pocket pools (slow water habitat embedded in a rapid often observed as large eddies behind emergent boulders or along the margin of the rapid adjacent to the bank). Pocket pools provide foraging and resting stations for trout in fast water habitat. Pool habitat in the lower section was, on average, large and deep. Aquatic habitats common in Reach 5 consisted of gravel- and small cobble-dominated rapids and riffles, and relatively long but shallow mid-channel scour pools. Sections of Reach 5 were characterized as depositional, with wide, relatively shallow habitats, pointbars, some floodplain development, and large amounts of stored sediment behind large wood jams. Measured stream gradients in Reach 5 ranged between two percent and three percent. Reach 5 contained a number of long (> 500 feet) homogenous rapids and riffles that were similar throughout the entire length in gradient, substrate size, amount and placement of instream LWM, and amount of pocket pool habitat. We generally look for subtle changes in physical features in long fast water habitats, such as slight changes in gradient or substrate size to break the habitat, but a number of rapids and riffles found in Reach 5 were remarkably consistent in gradient, substrate size, and amount of pocket pool habitat for the entire length. Other aquatic habitats recorded included a small number of debris dam pools, boulder-dominated cascades (Reach 1), and four special case habitats three waterfalls (Reach 1) and one man-made dam (South Fork Dam, located at the end of Reach 3). Side channel habitat was present in the four reaches surveyed. Side channels offered the best off-channel (fish rearing and velocity refuge) habitat in the low gradient sections of Reach 5. Many side channels appeared to have been created and maintained by large wood jams diverting water into these secondary channels. Side channels in the lower section offered some slow water refuge habitat, but typically did not differ from the main channel in terms of gradient, water velocity, and 1 Fast water habitat refers to rapids, riffles, and cascades, and slow water habitat refers to pools. The criteria for identifying fast water and slow water habitat is described in the Stream Inventory Handbook (2014). The terms fast water and slow water will be used interchangeably with rapids and pools, respectively throughout this report 11

17 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 substrate size. Side channel area comprised approximately one percent (Reach 5) to six percent (Reach 1 and Reach 2) of the total reach area. Channel substrate estimates and Wolman Pebble counts characterized the dominant substrate size classes throughout the lower section as boulder and large cobble (with substantial amounts of bedrock found in Reach 1). In Reach 5, substrate estimates and Wolman Pebble counts characterized the dominant substrate size as gravel and small cobble with substantial amounts of sand in both pool and riffle habitat. As a result, spawning habitat for resident trout was lacking in the lower section and abundant in Reach 5. Bedrock substrate played the greatest role in channel morphology in Reach 1. Large woody material, important in contributing to aquatic habitat complexity in many ways, was lacking in the lower section and moderately abundant in Reach 5. In Reach 1 through Reach 3, LWM amounts ranged from seventeen pieces/mile to twenty-eight pieces/mile. These amounts are considered low for west side (west of the Cascade crest) streams. Stream surveys on reference reaches (unimpaired, properly functioning, unmanaged streams) have recorded LWM amounts in excess of eighty pieces/mile (Bisson 1997). LWM amounts in Reach 5 were found to be moderately abundant (sixtyeight pieces/mile). Many pieces of wood in Reach 5 were associated with large wood jams. In many cases it was necessary to estimate wood counts in these features as individual lengths, and whether pieces engaged bankfull were difficult to determine. As previously mentioned, low instream LWM amounts in the lower section were partially attributed to the predominant early seral stage riparian vegetation. Conversely, the higher LWM amounts found in the upper section (Reach 5) were attributed to the mature riparian vegetation capable of providing instream LWM through natural recruitment. FISHERIES Fish surveys were conducted by direct observation using a mask and snorkel to determine fish species presence, abundance, and distribution. Our survey results showed a moderately sized population of rainbow trout (Oncorhynchus mykiss) in the lower section, and a small population of rainbow trout in the upper section (Reach 5). Also 12

18 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 reported were a small number of cutthroat trout (O. clarkii) in Reach 1 and Reach 2, and a small population of eastern brook trout (Salvelinus fontinalis) found throughout the four surveyed reaches. Rainbow trout and eastern brook trout distribution extended through Reach 5. Cutthroat trout distribution appears to be restricted to Reach 1 and Reach 2. Sculpin (Cottus spp) were the only native non-game fish species observed. Eastern brook trout were introduced to many Cascade streams and mountain lakes by the Oregon Department of Fish and Wildlife for the purpose of sport fishing. Other aquatic organisms observed included tailed frogs (Ascaphus truei), red-legged frogs (Rana aurora), Cascades frogs (Rana cascadae), and Pacific giant salamanders (Dicamptodon tenebrosus). No fresh water mussels were observed and no aquatic invasive species were reported. AFFECTED WATERS SOUTH FORK ROGUE RIVER BYPASS REACH PacifiCorp Energy (PacifiCorp) operates the Prospect No. 3 Hydroelectric Project in the upper Rogue River basin using water diverted from the South Fork Rogue River. In partial fulfillment of the Federal Energy Regulatory Commission s (FERC) Integrated Licensing Process, and as a result of scoping proceedings with stakeholders, PacifiCorp identified aquatic habitat inventory and fish community studies of the affected waters were warranted. PacifiCorp holds a water right to withdraw up to 150 ft 3 /sec of water from the South Fork Rogue River at the South Fork Impoundment located immediately downstream of the confluence of Imnaha Creek and the South Fork Rogue River (42 o N, 122 o W). A 172-foot wide, 24-foot high concrete dam impounds the South Fork Rogue River, and the resulting 1-acre impoundment feeds a waterway that conveys water to a powerhouse for electricity generation. Previous Studies A 1986 aquatic habitat and stream discharge study conducted between the South Fork diversion dam and the Prospect-Butte Falls Highway bridge concluded that water withdrawal for power generation would not negatively affect fish communities if a minimum of 10 ft 3 /sec were provided to the South Fork at the point of diversion (Campbell Craven Environmental Consultants, 1986). Other conclusions drawn from 13

19 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 these studies indicated that (1) there is little ground water inflow between the diversion dam and 2.5 miles downstream of the diversion dam and (2) the USGS stream gage located ¼ mile downstream of the diversion dam is generally indicative of the stream flow in this area. There is a significant inflow of ground water 2.5 miles to 3.5 miles downstream of the diversion dam. Further, ground water inflow generally lowers stream water temperatures in the middle to lower sections of this stretch between the diversion dam and the Prospect-Butte Falls highway. The lower gradient and wider and larger stream channel in the lower (downstream) section of the 1986 study area diminishes the effect ground water has on lowering stream temperature. The aquatic habitat survey results from the 1986 Campbell-Craven Report indicate a channel dominated by large cobble, boulder, and bedrock substrate that lacks small substrate (sand, gravel, and small cobble) suitable for spawning habitat used by resident rainbow trout. Further, the 1986 report concludes that the studied reach exhibits a lack of instream cover in the form of woody material, riparian vegetation, and a limited amount of undercut banks. The report characterized the channel morphology as a stair-step pattern consisting of runs and pools of various sizes and few riffle areas. The report also concluded that the lower mile of the study area (from the Prospect-Butte Falls bridge to a point one mile upstream) appeared to be better suited habitat for rainbow trout than the upper survey area due to lower stream gradients, larger pools, and higher proportions of cover provided by riparian vegetation. In very general terms, the results of the 2014 survey identify similarities in the descriptions and conclusions conveyed in the 1986 report, such as the large substrate dominated channel, the lack of fine sediments, and the lack of instream LWM. However, the Campbell-Craven report provided little aquatic habitat quantitative data to compare to data collected using the 2014 Stream Inventory protocol. Furthermore, definitions for aquatic habitat types, criteria for countable instream LWM, and area that constitute the riparian zone were dissimilar, making the two studies mostly incomparable. 14

20 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 With respect to the 1986 Campbell-Craven discharge study, our fish survey results showed decreased fish densities in the section of canyon directly below the diversion dam (Reach 3) when compared to the downstream reaches where stream flow is augmented by ground water in-flow (Reach 2 and Reach 1). The highest fish densities of the survey occurred in Reach 1 and Reach 2. Fish densities in the section most affected by water diversion (Reach 3) were similar to fish densities calculated in the reach upstream of the impoundment suggesting the flow regime that exists as a result of water diversion is sufficient to maintain a fish presence in the canyon section directly below the point of water diversion where loss of stream flow was most acute. The South Fork Dam has additional effects on channel substrate composition in the lower reaches. Substrate estimates and Wolman pebble counts clearly showed a channel dominated by large cobble and boulders and a lack of fine sediment (sand, gravel, and small cobble) in the reaches located below the dam, and substrate composition estimates and Wolman pebble counts showed a channel dominated by gravel and small cobble with substantial amounts of sand in the reach located upstream of the dam. The conclusion is that the blockage created by the South Fork Dam is inhibiting the passage of sand, gravel, and small cobble important for spawning habitat, interstitial habitat, and the prevention of channel hardening through substrate embeddedness. IMNAHA CREEK In 2002 SRG conducted a Level II aquatic habitat inventory and fish survey on 3.55 miles of Imnaha Creek beginning at the confluence with the South Fork Rogue Impoundment. Four reaches were identified and one reach, Reach 2 (1.35 miles), was located on corporate timberland. Imnaha Creek flows through a 100-foot to 200-foot wide flatfloored alluviated canyon. Mapped stream gradients ranged from two percent to four percent. The channel was entrenched to moderately entrenched with average entrenchment ratios ranging from 1.50 (Reach 1) to 1.05 (Reach 4). Dominant substrate size class based on visual estimates in every aquatic habitat and four Wolman pebble counts was gravel and cobble. Instream LWM was abundant in the three reaches located on RR-SNF land, and LWM was uncommon in the reach located on private timberland. 15

21 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 Similarly, the riparian habitat consisted of a large and mature tree class Douglas-fir and western hemlock forest on RR-SNF land, and small diameter early seral vegetation regenerating from past harvest on private timberland. In addition to Douglas-fir and western hemlock, other common riparian species included white fir, willow, vine maple, and ponderosa pine. Reported fish species in Imnaha Creek included rainbow trout, cutthroat trout, and eastern brook trout in reach densities that averaged fish/yd 2 for the lower three reaches. The upper reach (Reach 4) contained extremely low fish densities (0.003 fish/yd 2 ) as a result of very small aquatic habitats, cold water (5 o C), and two culverts that were estimated to act as impediments to upstream fish passage. In summary, with exception to channel size, Imnaha Creek was comparable to Reach 5 of South Fork Rogue River in terms of valley form, dominant substrate size class, stream gradient, amount of instream LWM, and fish densities. Notable differences between Imnaha Creek and Reach 5 of South Fork Rogue River include a relative greater amount of pool habitat in Reach 5 of South Fork Rogue River and a 1.35-mile reach (Reach 2) on Imnaha Creek located on private timberland that lacked instream LWM and contained a riparian habitat regenerating from timber harvest. Finally, cutthroat trout were reported in Reach 1 and lower Reach 2 of the South Fork Rogue River survey but not reported upstream of the South Fork dam, whereas cutthroat trout were reported in the survey of Imnaha Creek in This situation suggests further work to confirm cutthroat trout distribution in the upper South Fork Rogue River watershed occurs upstream of the South Fork dam and into Imnaha Creek. 16

22 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 REACH SUMMARIES REACH 1 Reach 1 began approximately 500 feet upstream of South Fork Rogue River s confluence with the Middle Fork Rogue River (042 o N, 122 o W NAD 83). We were unable to begin the survey at the confluence of the two forks because access by standard means was not advisable due to robust stream flow and a series of waterfalls into deep pools within a narrow, steep-walled, basalt gorge (Photos 1-3). Reach 1 was ended 1.70 miles upstream at the confluence with Buck Creek (042 o N, 122 o W). The reach was broken at the confluence with Buck Creek due to a change in canyon morphology and a change in stream flow from the contribution of Buck Creek (fifteen percent estimated contribution of volume of South Fork Rogue River). GEOMORPHOLOGY / HYDROLOGY A large portion of Reach 1 was located in a narrow, steeply sloped basalt canyon and a very narrow, box-like bedrock gorge (Photos 16-20). Approximately 0.4 miles downstream of the reach endpoint, canyon morphology shifts to a wider, moderately sloped canyon with a mild stream gradient and smaller channel substrate (Photos 21-25). Mapped channel sinuosity was very low (1.00) and average mapped channel gradient was 3.79 percent. The inner bedrock canyon was stable and only three instances of streambank erosion were noted for a total length of bank erosion of 155 feet (1.7 percent of reach length). All instances of bank instability were found in upper Reach 1 - upstream of the basalt canyon and bedrock gorge morphology. Average mapped valley width was estimated to be 105 feet, but ranged from 40 feet in the bedrock gorge to 200 feet in the wider, relaxed canyon of upper Reach 1. The USGS stream gage located on the South Fork Rogue River 0.25 miles downstream of the diversion dam recorded a discharge of 13 ft 3 /sec on August 7 10, 2014 with spiked discharge of 23 ft 3 /sec during the off-peak hours when electricity needs were low and less water was diverted from the South Fork. However, we estimated a discharge of 60 ft 3 /sec 70 ft 3 /sec in lower Reach 1 (Photo 8). 17

23 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 Channel substrate composition estimates were made at every pool and riffle in order to describe the streambed for those habitat types. These estimates were then averaged (but not corrected for habitat length) for the reach. The result depicts a boulder and cobble dominated channel for both pools and rapids. Bedrock was present in substantial amounts (sixteen percent fast water and twenty-eight percent slow water), and sand and gravel substrate were not abundant (Figure 1). Two Wolman pebble counts conducted in Reach 1 indicated a median channel substrate size (D 50 ) of 89 mm (small cobble) and 147 mm (large cobble). Wolman pebble count graphs for all reaches are found in Appendix D. In an effort to describe channel morphology, three cross section measurements were conducted in Reach 1. These results were averaged to describe an entrenched to moderately entrenched channel (entrenchment ratio of 1.39, range ) with a bankfull width-to-depth ratio of (Appendix C). Based on an average of hydrological data, substrate size estimates, stream gradient, photographs, and Wolman pebble counts, Reach 1 was classified as a B2/B3 Rosgen stream type (Rosgen 1996). 50 Figure 1. Average Substrate Composition South Fork Rogue River Reach 1 % Substrate Composition Slow water Fast water Silt/Clay/Sand Gravel Cobble Boulder Bedrock Particle Size 18

24 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 RIPARIAN HABITAT The inner riparian zone vegetation consisted of an overstory of sapling/pole, small tree, and large tree class Douglas-fir with an understory of western hemlock, bigleaf maple, alder, willow, and Pacific ninebark. The outer riparian zone 2 vegetation consisted of an overstory of small tree and large tree class Douglas-fir and western hemlock with an understory of madrone, Douglas-fir, western hemlock, and bigleaf maple as determined at snorkeled units. Reach 1 was located entirely on private corporate timberland managed intensively for timber production. The steep canyon of the lower and middle sections of Reach 1 protected the riparian vegetation from harvest in many areas due to poor access. Where access was better, harvest had occurred and we noted relatively recent clearcuts in the outer riparian zone in upper Reach 1 (SO 71). Similarly, we noted evidence of cattle grazing on the adjacent plateau but the steep canyon prevented cattle from accessing the riparian zone. The result of difficult access for timber harvest has left pockets of mature riparian trees that provide a limited potential for the recruitment of instream LWM. Conversely, much of the riparian forest of upper Reach 1, where access for timber harvest was possible, was in an early to mid seral stage and did not contain many trees large enough to provide instream LWM. Survey photographs located in Appendix F depict examples of current conditions of the riparian vegetation. No roads or road crossings were located in the riparian zone of Reach 1, and the stable basalt canyon geology precluded large inter canyon landslides that can have an adverse affect on the riparian habitat. 2 The riparian zone extends 100 feet out from each stream bank (right and left) and the inner riparian zone extends from the active channel out twenty-five feet. The outer riparian zone occupies the remaining seventy-five feet, from 25 feet to 100 feet. Riparian vegetation characterization was performed at every snorkeled habitat (every fifth pool and every tenth rapid) and surveyors estimated the inner riparian zone and outer riparian zone widths when characterizing the vegetation. 19

25 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 AQUATIC HABITAT The aquatic habitats of Reach 1 consisted mostly of deep-channeled rapids and deep midchannel scour pools. Also identified were four low gradient riffles (upper Reach 1), four large bedrock trench pools (bedrock gorge), three short cascades, three waterfalls (basalt canyon and bedrock gorge), several plunge pools (lower and mid Reach 1), and eight side channels (throughout). In general, fast water comprised fifty-four percent of the total habitat area, slow water comprised forty percent, and side channels six percent of the total habitat area (Figure 2). Specifically, fast water consisted of forty-two percent rapids, ten percent low gradient riffles, and two percent steep cascades. Slow water consisted of twenty-nine percent mid-channel scour pools, seven percent plunge pools, and four percent bedrock trench pools (Figure 3). Much of the side channel habitat observed in Reach 1 did not provide conditions that were distinctly different from the main channel. Figure 2. Habitat Composition South Fork Rogue River Reach 1 SC 6% Slow water 40% Fast water 54% Thirty-six pools were identified in Reach 1 for a pool frequency of twenty-one pools/mile. Twenty-nine pools exceeded three feet in depth (residual depth) for a deep pool frequency of seventeen pools/mile. Average residual maximum pool depth for Reach 1 was 5.4 feet and the deepest pool was 18.3 feet (estimated residual depth at SO 49, SSTR 25). Average pool tail crest was 1.5 feet. The longest pool was 385 feet (SO 52, SSTR 26), average pool length was 110 feet, and average pool width was thirty-seven feet. Total pool area in Reach 1 was approximately 16,080 yd 2. In short, pools were 20

26 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 large and deep and dominated by bedrock, boulder, and cobble substrate. Twenty-eight fast water units were identified in Reach 1. Average fast water depth was 1.7 feet, average fast water maximum depth was 3.3 feet, and average fast water width was forty feet. The longest fast water unit was 456 feet (SO 60, FTRF 24) and average fast water length was 177 feet. Total fast water area in Reach 1 was approximately 22,034 yd 2. Fast water habitat in lower- and mid-reach 1 was deep channeled, boulder-dominated with abundant pocket pool habitat, and provided quality habitat for large fish. Figure 3. South Fork Rogue River Channel Unit Composition Reach 1 FTCC 2% SSPL 7% SC 6% SSTR 4% FTRF 10% SSMC 29% FTRP 42% Reach 1 lacked instream LWM as a result of two likely factors. First, as previously mentioned, a large portion of the riparian vegetation was regenerating from timber harvest and does not contain enough large trees for a sufficient supply of instream wood. Second, the large canyon magnitude and periodic powerful winter flows likely have the ability to flush large wood from this section. We counted a total of thirty-five pieces of LWM (size classes combined) for a reach frequency of 20.6 pieces/mile. Specifically, we counted thirty-one pieces of small class LWM (18.2 pieces/mile), three pieces of medium class LWM (1.8 pieces/mile), and one piece of large class LWM (0.6 pieces/mile). Wood was found in Reach 1 as scattered pieces and some pieces tied up in small wood 21

27 South Fork Rogue River Level II Stream Survey, Siskiyou Research Group, March 2015 complexes. Several pieces of wood (both scattered and in jams) were stranded above the bankfull plane by high water (photos 9,12) and thus were not tallied, but represent a potential for near-term recruitment of LWM. In general, instream LWM did not play a large role in aquatic habitat morphology or complexity in Reach 1. Figure 4 compares amount (in pieces/mile) of LWM between the four reaches of South Fork Rogue River. Figure 4. Large Woody Material South Fork Rogue River Reach 5 Reach 3 Reach 2 Reach Pieces of Large Woody Material / Mile Small (12"dia. 25' from large end) Medium (24"dia. 50' from large end) Large (36" dia. 50' from large end) FISHERIES Fish identification and enumeration were obtained from direct observation using a mask and snorkel. Sampling frequency, based on a random start, was every fifth slow water unit (pool) and every tenth fast water unit (rapid, riffle, or cascade). We calculated moderately high fish densities based on snorkel counts. Seven slow water units and three fast water units were snorkeled in Reach 1 sampling area of 3,977 yd 2 and 1,552 yd 2, respectively. We identified rainbow trout, cutthroat trout, and eastern brook trout. In the seven snorkeled slow water habitats we counted twenty-eight size-class 1 (0-100 mm), 229 size-class 2 (100 mm 200 mm), and twenty-five size class > 3 (> 200 mm) rainbow trout; sixteen size class 2 and eighteen size class > 3 cutthroat trout; and five size class 2 and one size class > 3 eastern brook trout for a combined density of fish/yd 2. In the 22