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HomeMy WebLinkAbout200909-PCA_ADFG_PlanReviewSbmtlMR. JOSH BREKKEN, HABITAT BIOLOGIST ALASKA DEPARTMENT OF FISH AND GAME KNUTSON CREEK HYDRO PROJECT: PLAN SUBMITTAL SEPTEMBER 9, 2020 POLARCONSULT ALASKA, INC. PAGE 2 OF 10 OVERVIEW OF FISH AND AQUATIC HABITAT The water bodies that could be affected by project development include the bypassed reach of Knutson Creek (RM 1.29 up to RM 2.59), and the minor waterways that are crossed by the project’s access roads, trails, and other features. The project must conform to both AS 16.05.841 (Fishway Act) and AS 16.05.871 (Anadromous Fish Act). Conformance with the Fishway Act is achieved with a fish pass located at the diversion structure that will support bidirectional migration of fish. Fish passage is maintained through the remainder of Knutson Creek by stream flow in the seasons when fish are present in these waters. Conformance with the Anadromous Fish Act is achieved by avoiding to the extent practical impacts to anadromous fish spawning habitat. To mitigate potential unavoidable impacts to spawning habitat, new habitat is provided in the diversion impoundment to replace lost and/or degraded habitat in the bypass reach. Extensive consultations with ADFG, field study, and analysis in 2012 and from 2016 through 2018 quantified expected project impacts to fish habitat in the bypass reach of Knutson Creek and appropriate mitigation measures to address these impacts. Table 1 summarizes known and/or pertinent Knutson Creek fisheries surveys and supporting analyses conducted to date. Table 1: Knutson Creek Fish Habitat Surveys, Analyses, and Key Correspondence Survey / Report Date (Citation) Activity Summary of Findings August 11, 2004 (HDR 2011) Visual survey from approximately RM 1.2 to 1.5. - 89 adult sockeye salmon. August 23-24, 2012 (ABC 2012) Visual survey and minnow trapping from RM 1.2 to 2.6. - 43 adult sockeye salmon (RM 1.3-2.1) - 6 sculpin (RM 1.6-1.7) - 256 resident Dolly Varden (RM 1.3-2.6) - Minimal spawning habitat and use in bypass reach. February 19, 2016 (Polarconsult 2016a) Fish Habitat Permit, Pre- Application Submittal. Project description, plans, fish survey reports, hydrology, existing permits, bypass reach photographs. March 2, 2016 (Polarconsult 2016b) Fish Habitat Permit Application Included site restoration plan. March 25, 2016 (Polarconsult 2016c) Response to ADFG questions on application. Responses to questions on site biology, hydrology, project proposal, post-construction monitoring plan. April 5, 2016 (ADFG 2016) Visual survey of bypass reach habitat, electrofishing surveys of resident fish, and flow measurements, RM 1.3 to RM 2.15. - RM 1.29 pool1 is the major sockeye spawning habitat in survey reach, other instances of suitable gravels in bypass reach are usually isolated pockets along stream margins. - Captured Dolly Varden and sculpin sp., fish densities highest in lower portion of survey reach. - Main stem flow 107 cfs. Above normal flow of ~10 to 20 cfs for this time of year. May 4, 2016 (Polarconsult 2016d) Fisheries mitigation and study proposal Propose framework for studies conducted by FRI. MR. JOSH BREKKEN, HABITAT BIOLOGIST ALASKA DEPARTMENT OF FISH AND GAME KNUTSON CREEK HYDRO PROJECT: PLAN SUBMITTAL SEPTEMBER 9, 2020 POLARCONSULT ALASKA, INC. PAGE 3 OF 10 Table 1 (Cont.): Knutson Creek Fish Habitat Surveys, Analyses, and Key Correspondence Survey / Report Date (Citation) Activity Summary of Findings May 19, 2016 (Polarconsult 2016e) Memo clarifying points in May 5 meeting with ADFG - Clarify creek hydrology, bypass reach of Knutson Creek is not sockeye rearing habitat, spawning timing in different reaches of creek, and suitability/considerations of tailrace as spawning habitat. August 15, 2016. (FRI 2016) -249 adult sockeye salmon (RM 1.24- 2.59) (67% in RM 1.29 pool)1 August 25, 2016. (FRI 2016) Visual surveys from RM 1.24 to 2.59. Identified four most significant spawning sites in bypass reach for analysis. - 192 adult sockeye salmon (RM 1.24-2.59) (66% in RM 1.29 pool)1 March 28-31, 2017 (Polarconsult 2017b) Overwintering resident fish survey in upper bypass reach from RM 2.03 to 2.59. No fish observed or caught in traps. June 6, 2017 (Polarconsult 2017c) Hydrologic analysis letter report of four bypass reach spawning sites identified in FRI 2016. Analysis of RM 2.31 RB side channel not surveyed by FRI. - Sites 1&2 (RM 1.29 pool) are viable for spawning.1 - Site 3 (RM 2.55) not viable for spawning. - Site 4 (RM 2.59 viable for spawning. - Move tailrace to discharge at RM 1.29 pool. - Design diversion structure to reduce impact to site 4. - Determine RM 2.31 side channel does not receive winter surface flow from main stem. Lower 0.09 mi. has perennial surface flow from side tributaries. Upper 0.13 mi. not viable habitat. August 11, 2017 (Polarconsult 2017d) Supplement memo addressing ADFG review questions on Polarconsult 2017c. - Clarify representative winter flow and rationale for using mode instead of mean or median. - Discussion of methods for estimating subbasin flow. - Discussion of need for, economic costs of, and reliability of infrastructure to provide an in-stream flow reservation on Knutson Creek. November 7, 2017 (ADFG 2017) Install temperature sensors at spawning site 5, RM 1.87. 7 HOBO temperature loggers installed into creek substrate at spawning site 5 to assess winter hydrologic conditions for egg viability. Main stem flow ~120 cfs. May 1, 2018 (ADFG 2018) Recover temperature sensors at spawning site 5, RM 1.87. All loggers recovered and downloaded. Temperature indicates gravels at all 7 sites remained wetted through the winter season. Main stem flow ~65 cfs. May 9, 2018 (Polarconsult 2018a) Hydrology study site visit Gauge download and measurements. Flow too high to measure with available equipment. Supplemental field measurements at spawning site 5. June 11, 2018 (Polarconsult 2018b) Hydrologic assessment of spawning habitat at spawning site 5, RM 1.87. Conclude that project water diversions would result in loss of 60 ft2 of the 450 ft2 of viable spawning habitat at site 5. Mitigated with new habitat area at diversion site. ADFG: Alaska Department of Fish and Game cfs: cubic feet per second ft2: square feet FRI: Fisheries Research Institute, University of Washington. mi: mile RM: river mile Note 1. The RM 1.29 pool was formed during a flood event in October 2013 and completely filled during a flood event in August 2018. It is considered an uncommon transient feature in the context of the characteristic creek morphology in the bypass reach of Knutson Creek. MR. JOSH BREKKEN, HABITAT BIOLOGIST ALASKA DEPARTMENT OF FISH AND GAME KNUTSON CREEK HYDRO PROJECT: PLAN SUBMITTAL SEPTEMBER 9, 2020 POLARCONSULT ALASKA, INC. PAGE 4 OF 10 1.0 Existing Environmental Setting 1.1 Knutson Creek Knutson Creek is documented anadromous fish habitat for Sockeye salmon spawning, with multiple discrete spawning sites documented downstream, within, and upstream of the project bypass reach (RM 1.29 to RM 2.59) and Sockeye salmon presence and/or spawning up to RM 6.3. Presence of Arctic Char is also documented. Knutson Creek tributaries and other minor drainages in the project footprint are not listed as important anadromous waters.1 Knutson Creek is also documented habitat for resident Dolly Varden and Sculpin. Most of the creek’s productive Sockeye spawning habitat is located downstream of the project along the shores of Lake Iliamna and in the bottom ½ mile of the creek. Sockeye spawning habitat in the bypass reach is characterized as marginal to unproductive. Surveys in 2016 and 2018 identified 5 spawning areas in the bypass reach (see Table 2), with the balance of the reach characterized as having isolated pockets of suitable spawning gravels along the stream margins.2 Visual surveys in August 2004, 2012, and 2016 identified 10s to 100s of adult sockeye in the bypass reach. Hydrologic analysis determined that specific spawning sites at the diversion (site 4, RM 2.59), lower bypass reach (site 5, RM 1.89), and tailrace (sites 1 and 2, RM 1.29 pool) are viable spawning habitat. Site 3 (upper bypass reach, RM 2.45) and other isolated areas along the stream margins in the bypass reach are not viable habitat because they will normally dewater in the winter low flow season and egg-bearing strata will be subjected to sustained below-freezing conditions. Current estimated total productive spawning habitat naturally occurring in the bypass reach of Knutson Creek is 6,350 to 7,200 square feet (see Table 2). Surveys indicate resident fish are present during the summer months throughout the bypass reach. Under typical winter conditions, surveys indicate resident fish are not present in the upper bypass reach (RM 2.09 to 2.59) and are present in the lower bypass reach (RM 1.29 to 2.09) with increasing density downstream.3 1.2 Other Minor Streams and Tributaries in the Project Footprint Project roads and trails cross several minor streams and tributaries (see Table 3). None of these waters are cataloged by ADFG as important anadromous waters. Three Clear Creek tributaries crossed by the project access road and Knutson tributaries ‘R1’ and ‘L1’ may provide habitat for resident fish. Clear Creek and other creeks and minor drainages have intermittent surface flow and/or probable fish passage barriers and are considered unlikely to contain resident fish. 1 ADFG 2020. 2 ABC 2012, ADFG 2016, FRI 2016. 3 ADFG 2016 and Polarconsult 2017b. MR. JOSH BREKKEN, HABITAT BIOLOGIST ALASKA DEPARTMENT OF FISH AND GAME KNUTSON CREEK HYDRO PROJECT: PLAN SUBMITTAL SEPTEMBER 9, 2020 POLARCONSULT ALASKA, INC. PAGE 5 OF 10 Table 2: Summary of Bypass Reach Sockeye Spawning Sites and Project Impacts Adult Sockeye Count 1 Spawning Site Description Hydrologic Conditions Support Egg Incubation? Natural Area (ft2) Area Lost/ Gained Due to Project (ft2) 8/11 2004 8/13 2012 8/15 2016 8/25 2016 Sites 1 + 2 RM 1.29. River-left pool. Site of most observed spawning activity in bypass reach.1, 2 Yes Approx 3,2002 NA 2 NA 2 NA 2 167 127 Site 5 RM 1.87. River-left gravel/cobble bar. Yes 450 – 60 NS <24 4 6 0 Right Bank Side Channel RM 2.31 to RM 2.55. River-right side channel with observed spawning activity at both ends. 1 Lower 0.09 mi. receives perennial flow from tributaries. Upper 0.13 mi. dewaters in late fall. Lower: Yes Mid: Maybe Upper: No ~3,800 ~850 0 0 ~ – 850 0 NS NS NS NS NS NS NS NS NS NS NS NS Site 3 RM 2.55. River-right lateral bar where Side Channel departs from main stem. No NA NA NS NR 7 16 Site 4 RM 2.59. River-right perched pool where a side channel rejoins main stem. Yes ~2,100 – 500 NS NR 10 1 Remainder of Bypass Reach RM 1.12 to RM 2.59. High-velocity large- cobble stream bed with marginal to absent spawning habitat. Existent habitat is isolated pockets of suitable gravels along stream margins. 1 No 5 NS NS NA 19 59 48 Diversion Pool Impoundment created by project at RM 2.59 Yes 0 +10,900 NA NA NA NA Bypass Reach Net Total 7,200 +9,490 89 3 43 249 192 NA: Not applicable. NR: Not reported. Sockeye observed at this site (if any) were not reported separately from total survey results. NS: Not surveyed. 1. As reported by biologists conducting fisheries surveys (HDR 2011, ABC 2012, FRI 2016, ADFG 2016). 2. Site was created by a flood in October 2013, and did not exist at time of survey. Site was completely filled by a flood in August 2018 and no longer exists. Therefore it is not included in total bypass spawning area. 3. Survey reach not clearly documented and is estimated to be RM 1.2 to 1.5. Fish count is survey total. 4. 24 Sockeye reported between RM 1.50 and RM 1.87. Specific locations were not reported (ABC 2012). 5. Based on similarities to site 3 and study findings at site 3. MR. JOSH BREKKEN, HABITAT BIOLOGIST ALASKA DEPARTMENT OF FISH AND GAME KNUTSON CREEK HYDRO PROJECT: PLAN SUBMITTAL SEPTEMBER 9, 2020 POLARCONSULT ALASKA, INC. PAGE 6 OF 10 Table 3: Summary of Project Water Crossings Culvert Description Project Feature and Station1 Water Body Description Quantity and Diameter Length (feet) Slope (%) Design Flood (cfs) Capacity (cfs) Access Road 44+03 Clear Creek tributary (presumed Class III/IV stream 2, 3) 1-18” 50’ 14% 6 11 Access Road 46+15 Clear Creek tributary (presumed Class III/IV stream 2, 3) 2-30” 40’ 7.5% 27 60 Access Road 51+40 Clear Creek tributary (presumed Class III/IV stream 2, 3) 1-30” 40’ 2.5% 15 30 Access Road 65+30 Knutson Creek tributary ‘R1’ (Class II/III stream) See note 5 319 > 1,000 Access Road 83+80 Knutson Creek (RM 1.81) (Class I stream) Bridge spanning Creek OHWM 6,319 > 10,000 Access Road 91+89 Minor drainage (Class IV stream 4) 1-18” 40’ 0% 3 11 Access Road 98+50 Knutson Creek tributary ‘L1’ (Class II/III stream) See note 5 603 > 1,000 cfs: cubic feet per second OHWM: ordinary high water mark 1. Culverts provided for ditch relief or intermittent surface flow are not listed. 2. Clear Creek is not a perennial stream at the runway. Based on site conditions, the creek at the runway likely becomes entirely hyporheic under common summer low flows. Resident fish presence in the creek is unknown. 3. Presumed natural fish passage barrier (sustained >20% gradient) exists within 200’ of culvert inlet. 4. Presumed natural fish passage barrier (~60% gradient for 30 vertical feet) exists downstream of culvert outlet. 5. Crossing is a creek ford. See narrative and design drawings. On Table 3, water resources in the project footprint are characterized using the U.S. Forest Service’s four-tiered classification system for fish streams.4 Summary characteristics of this schema follow. Class I: Streams or lakes with anadromous or adfluvial fish or fish habitat, or high quality resident fish waters or habitat above fish migration barriers known to provide reasonable enhancement opportunities for anadromous fish. Class II: Streams or lakes with resident fish or fish habitat, generally with channel gradients of 6 to 25+ percent. Class III: Perennial and intermittent streams with no fish populations but which have sufficient flow or sediment/debris transport to have an immediate influence on downstream water quality or fish habitat capability. Class IV: Other intermittent, ephemeral, and small perennial channels with insufficient flow to directly influence downstream water quality of fish habitat capability. Non-streams: minor drainages not meeting above criteria, generally intermittent and bankfull width of less than one foot. 4 USFS 2016 at page 7-60. MR. JOSH BREKKEN, HABITAT BIOLOGIST ALASKA DEPARTMENT OF FISH AND GAME KNUTSON CREEK HYDRO PROJECT: PLAN SUBMITTAL SEPTEMBER 9, 2020 POLARCONSULT ALASKA, INC. PAGE 7 OF 10 2.0 Expected Environmental Impacts 2.1 Knutson Creek The project would not impact Knutson Creek fish habitat upstream of the diversion site (RM 2.59) or downstream of the tailrace (RM 1.29). As proposed, the project would eliminate or degrade approximately 1,410 square feet of existing sockeye spawning habitat in the bypass reach of Knutson Creek. This would reduce natural productive spawning habitat in the bypass reach from 7,200 square feet to 5,790 square feet. This loss would be mitigated by creating 10,900 square feet of new productive spawning habitat at the diversion impoundment, increasing the area of productive spawning habitat in the bypass reach from 7,200 square feet to 16,690 square feet (see Table 3). A summary of spawning habitat in the bypass reach that would be impacted by the project follows. - Approximately 500 of the 2,100 ft2 of viable spawning habitat at Site 4 would be filled for the diversion structure and lost. - No significant impact at spawning site 3, which is non-viable spawning habitat during typical winter conditions due to natural dewatering and freezing of redds. - No impact to spawning habitat potentially present in the lower reach (RM 2.31 to RM 2.40) of a right-bank side channel as it would be sustained by lateral tributary inflows that are not affected by project operations. - Approximately 850 ft2 (from RM 2.40 to 2.42) of spawning habitat potentially present in the mid-reach of this right-bank side channel could be dewatered. Prospective Sockeye fry production from this area would normally be lost as redds would expectedly freeze and die during typical winter conditions. - No significant impact to spawning habitat potentially present in the upper reach (RM 2.42 to 2.55) of this right-bank side channel as it is non-viable under typical natural winter conditions. - Approximately 60 of the 450 ft2 of viable spawning habitat at Site 5 would be dewatered due to project water diversions. Sockeye fry production from this area would expectedly be lost as redds would freeze and die due to decreased flow during typical winter conditions. - No impact at spawning sites 1 and 2 as they were completely filled by a flood event in August 2018 and no longer exist. Also, the project tailrace discharges to this area which would maintain natural hydrologic conditions if this spawning habitat was still present. - No significant impact to other isolated pockets of suitable spawning gravels along the creek margins as they are non-viable spawning habitat during typical winter conditions due to natural dewatering and freezing of redds. - The diversion structure impoundment would create a new permanent pool in the creek. The creek bed under this pool that would be perennially wetted and outside of the flush gate scour zone will measure 10,900 ft2. MR. JOSH BREKKEN, HABITAT BIOLOGIST ALASKA DEPARTMENT OF FISH AND GAME KNUTSON CREEK HYDRO PROJECT: PLAN SUBMITTAL SEPTEMBER 9, 2020 POLARCONSULT ALASKA, INC. PAGE 8 OF 10 2.2 Other Minor Streams and Tributaries in the Project Footprint The flow regime at other minor streams and tributaries in the project footprint will not be altered by the project. At these water features, project impacts are limited to (1) potential temporary water quality impacts (increased suspended sediment transport) during construction consistent with a SWPPP and (2) creation of potential fish barriers due to improper installation or maintenance of water crossings. With the exception of Knutson Creek tributaries ‘R1’ and ‘L1’, these minor streams are crossed with culverts sized for their respective design floods.5 Culvert inlet and outlet inverts are specified to be aligned to and set flush with the local main channel thalweg (when present), so hydraulic conditions at culvert inlets and outlets will not create fish passage barriers. In most instances project alignments follow the toe of valley side walls. This means that water crossings are generally located close to or above the inferred natural upstream limit of fish passage, which minimizes the upstream length of minor streams that could be isolated. Knutson tributary ‘R1’ and ‘L1’ crossings are armored fords sized to pass their design floods. 3.0 Proposed Protection, Mitigation, and Enhancement Measures The following measures are proposed to protect, mitigate, and or enhance fish resources in the project footprint. 1. The project has been designed to minimize fisheries impacts by: a. RM 1.2 equipment ford has been eliminated and replaced by a heavy-equipment rated bridge at RM 1.81. b. Access road alignment has been adjusted to minimize potential fish habitat upstream of minor water crossings. c. Powerhouse site and tailrace discharge have been moved upstream ~400 feet to discharge to spawning habitat pool and avoid adverse hydrologic impacts to fish habitat. d. Diversion site designed to minimize fill to spawning site 4. e. Diversion impoundment provides significant increase (~2.5x) in available spawning habitat in bypass reach. 2. A SWPPP will be prepared and followed to avoid and/or minimize sediment discharges to project waters during project construction consistent with APDES General Construction Permit guidelines and DOA Section 404 Permit terms and conditions. 3. Timing of in-water work will be coordinated with ADFG to avoid and/or minimize impacts to salmon spawning and redd incubation. 4. Development of operation plan for diversion flush gate and impoundment management will be coordinated with ADFG to maintain viability of spawning habitat in impoundment, consistent with project operational and safety requirements. No additional protection, mitigation or enhancement measures specific to fish and aquatic habitat are proposed. 5 100-year flood at Knutson Creek, scaled to each culvert by the ratio of respective basin areas. MR. JOSH BREKKEN, HABITAT BIOLOGIST ALASKA DEPARTMENT OF FISH AND GAME KNUTSON CREEK HYDRO PROJECT: PLAN SUBMITTAL SEPTEMBER 9, 2020 POLARCONSULT ALASKA, INC. PAGE 9 OF 10 4.0 References ABC 2012. Alaska Biological Consulting. A Fisheries Survey of Upper Knutson Creek Associated with Potential Hydroelectric Development for Pedro Bay, Alaska. Technical Report 12-011. Lakeside, MT. September 2012. ADFG 2016. Alaska Department of Fish and Game (ADFG). April 5, 2016 Knutson Creek Site Visit Memo. Josh Brekken, ADFG Habitat Biologist. April 18, 2016. Anchorage, Alaska. ADFG 2017. ADFG. November 7, 2017 Knutson Creek HOBO Logger Deployment Trip Report Memo. Josh Brekken, ADFG Habitat Biologist. November 10, 2017. Anchorage, Alaska. ADFG 2018. ADFG. May 1, 2018 Knutson Creek HOBO Logger Retrieval Trip Report Memo. Josh Brekken, ADFG Habitat Biologist. May 7, 2018. Anchorage, Alaska. ADFG 2020. ADFG. Catalog and Atlas of Waters Important for the Spawning, Rearing, or Migration of Anadromous Fishes. Mapper accessed July 8, 2020. https://www.adfg.alaska.gov/sf/SARR/AWC/index.cfm?ADFG=main.interactive FRI 2016. Fisheries Research Institute, University of Washington, Alaska Salmon Program. Spawning Ground Survey of Upper Knutson Creek, Iliamna Lake, Alaska. Principal Investigator Dr. Curry Cunningham. November 2016. HDR 2011. HDR, Inc. and Three Parameters Plus, Inc. September 8, 2011. Pebble Project Environmental Baseline Document 2004 through 2008. Chapter 13. Vegetation, Bristol Bay Drainages and Chapter 14. Wetlands and Water bodies, Bristol Bay Drainages. Anchorage, AK. Polarconsult 2016a. Polarconsult Alaska, Inc. Pre-Application Meeting Materials for Knutson Creek Hydroelectric Project, Pedro Bay, Alaska. February 19, 2016. Anchorage, Alaska. Polarconsult 2016b. Polarconsult Alaska, Inc. Knutson Creek Hydro Project Fish Habitat Permit Application and Restoration Plan. March 2, 2016. Anchorage, Alaska. Polarconsult 2016c. Polarconsult Alaska, Inc. Response to ADFG March 16 Questions on Fish Habitat Permit Application for Knutson Creek Hydro Project, Pedro Bay, Alaska. March 25, 2016. Anchorage, Alaska. Polarconsult 2016d. Polarconsult Alaska, Inc. Knutson Creek Hydro Project Fisheries Mitigation Proposal. May 4, 2016. Anchorage, Alaska. Polarconsult 2016e. Polarconsult Alaska, Inc. Knutson Creek Hydro Project, Pedro Bay, Alaska. Clarification and Additional Information RE May 5, 2016 Permitting Meeting. May 19, 2016. Anchorage, Alaska. MR. JOSH BREKKEN, HABITAT BIOLOGIST ALASKA DEPARTMENT OF FISH AND GAME KNUTSON CREEK HYDRO PROJECT: PLAN SUBMITTAL SEPTEMBER 9, 2020 POLARCONSULT ALASKA, INC. PAGE 10 OF 10 Polarconsult 2017b. Polarconsult Alaska, Inc. Late Winter Fisheries Survey of Knutson Creek Associated with Potential Hydroelectric Development for Pedro Bay, Alaska. May 15, 2017. Anchorage, Alaska. Polarconsult 2017c. Polarconsult Alaska, Inc. Hydrologic Assessment of Spawning Habitat at Knutson Creek and Recommended Project Modifications to Avoid / Mitigate Fisheries Impacts. June 6, 2017. Anchorage, Alaska. Polarconsult 2017d. Polarconsult Alaska, Inc. Supplement to June 2017 Knutson Creek Hydrology / Fisheries Study Reports. August 11, 2017. Anchorage, Alaska. Polarconsult 2018a. Polarconsult Alaska, Inc. May 9, 2018 Site Visit to Knutson Creek, Trip Report. May 25, 2018. Anchorage, Alaska. Polarconsult 2018b. Polarconsult Alaska, Inc. Supplemental Hydrologic Assessment of Spawning Habitat at Knutson Creek Hydro Project Bypass Reach (Spawning Site 5). June 11, 2018. Anchorage, Alaska. USFS 2016. U.S. Forest Service. Tongass National Forest, Land and Resource Management Plan (R10-MB-769j). December 2016.