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HomeMy WebLinkAbout03.09.26 Board Correspondence - FW_ Environmental and Recreational Compliance Report submitted in FERC P-803-124 byFrom:Clerk of the Board To:BOS Cc:Cannon, Jamie; Loeser, Kamie Subject:Board Correspondence - FW: Environmental and Recreational Compliance Report submitted in FERC P-803-124 by Date:Monday, March 9, 2026 2:52:45 PM Please see Board Correspondence - -----Original Message----- From: 'FERC eSubscription' <eSubscription@ferc.gov> Sent: Monday, March 9, 2026 2:06 PM Subject: Environmental and Recreational Compliance Report submitted in FERC P-803-124 by .ATTENTION: This message originated from outside Butte County. Please exercise judgment before opening attachments, clicking on links, or replying.. On 3/9/2026, the following Filing was submitted to the Federal Energy Regulatory Commission (FERC), Washington D.C.: Filer: <Not available> Docket(s): P-803-124 Lead Applicant: Pacific Gas and Electric Company Filing Type: Environmental and Recreational Compliance Report Description: Pacific Gas and Electric Company submits Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Technical Report re the DeSabla-Centerville Hydroelectric Project under P-803. To view the document for this Filing, click here https://urldefense.com/v3/__https://elibrary.ferc.gov/eLibrary/filelist?accession_num=20260309- 0002__;!!KNMwiTCp4spf!FJFTt35G03ngIjXF- POaEtlLlOrgkZv2kvxwkBdNCXDGIbnVOVhh6Wo0G5iXati3mqisyHcBxx47NjTfw3FnNTzL1wleUOkZ7Wrc$ To modify your subscriptions, click here: https://urldefense.com/v3/__https://ferconline.ferc.gov/eSubscription.aspx__;!!KNMwiTCp4spf!FJFTt35G03ngIjXF- POaEtlLlOrgkZv2kvxwkBdNCXDGIbnVOVhh6Wo0G5iXati3mqisyHcBxx47NjTfw3FnNTzL1wleUKf0YhX-$ ------------------------------------------------------------------------ Please do not respond to this email. Online help is available here: https://urldefense.com/v3/__http://www.ferc.gov/efiling-help.asp__;!!KNMwiTCp4spf!FJFTt35G03ngIjXF- POaEtlLlOrgkZv2kvxwkBdNCXDGIbnVOVhh6Wo0G5iXati3mqisyHcBxx47NjTfw3FnNTzL1wleUIYCTQPi$ or for phone support, call 866-208-3676. ,L'AtirgAL„Aft, RIG/NA L . --'yam;.: nib IlAR P I: 52 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 tri Pacific Gas and Electric Company tN i)1 Power Generation 300 Lakeside Drive Oakland, CA 94612 Mailing Address: P.O. Box 28209 Oakland, CA 94604 March 4, 2026 Via U.S. Postal Service Debbie-Anne Reese, Secretary Federal Energy Regulatory Commission Division of Hydropower Administration and Compliance 888 First Street, NE Washington, D.C. 20426 RE: DeSabla-Centerville Hydroelectric Project, FERC No. 803-124 Butte Creek Foothill Yellow-Legged Frog Monitoring 2025 Technical Report Dear Secretary Reese: This letter presents the Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Technical Report to the Federal Energy Regulatory Commission's (FERC) for Pacific Gas and Electric Company's (PG&E) DeSabla-Centerville Hydroelectric Project, FERC No. 803. On August 15, 2025, FERC approved the Foothill Yellow-legged Frog Study Plan: Butte Creek 2025-2028. Pursuant to FERC's August 15, 2025, Order, PG&E provided a draft report to the California Department of Fish and Wildlife (CDFW) and the United States Fish and Wildlife Service (USFWS) by email on January 22, 2025. On February 19, 2026, comments were received from the USFWS, and CDFW requested a time extension until February 27,2026 to comment on the report. On February 19,2026, PG&E requested that CDFW provide comments by February 25, 2026, to be incorporated in the consultation record associated with the report. PG&E received no comments from CDFW. PG&E is submitting this hard-copy package as a refile of the Annual Foothill Yellow-Legged Frog (FYLF) Monitoring Report. On March 2, 2026, PG&E electronically filed the cover letter and Enclosures 2 and 3; however, a technical issue within FERC's eLibrary prevented upload of Enclosure 1 despite multiple troubleshooting efforts. PG&E promptly notified FERC and contacted FERC Online Support, but the issue remains unresolved. Consistent with FERC staff guidance, PG&E is refiling the complete package via hard copy, and this submission replaces the prior partial electronic filing. The Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Technical Report dated March 2026 is provided as (Enclosure 1). The comment and response matrix is provided as (Enclosure 2). Documentation for Agency consultation is submitted as (Enclosure 3). Documentation on the technical issue and related FERC communication is included as (Enclosure 4). Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Debbie-Anne Reese, Secretary March 4, 2026 Page 2 If you have questions or comments regarding this matter, please contact Duncan Drummond, license coordinator for PG&E, at (530) 215-9678 Sincerely, Sky Ramirez-Doble Senior License Coordinator Enclosures: 1.Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Technical Report 2.Comment and Response Matrix 3.Documentation of Agency Consultation 4.Documentation of Technical Issue Communication with FERC Document Accession #: 20260309-0002 Filed Date: 03/09/2026 ENCLOSURE 1 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 PACIFIC GAS AND ELECTRIC COMPANY Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Technical Report March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 This Page Intentionally Left Blank * Document Accession #: 20260309-0002 Filed Date: 03/09/2026 PACIFIC GAS AND ELECTRIC COMPANY Butte Creek Foothill Yellow-legged Frog Monitoring 2025 TECHNICAL REPORT March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Citation: Pacific Gas and Electric Company. 2026. Butte Creek Foothill Yellow-legged Frog Monitoring 2025. March 2026. Oakland, CA. Prepared by Stillwater Sciences, Berkeley, CA. Document Accession #: 20260309-0002 Filed Date: 03/09/2026 tif! & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 TABLE OF CONTENTS Executive Summary 1.0 Background 1-1 2.0 Monitoring Area 2-1 3.0 Methods 3-1 3.1 Visual Encounter Surveys 3-1 3.2 Habitat Assessments and Transects 3-2 4.0 Results 4-1 4.1 Visual Encounter Surveys 4-1 4.1.1 Foothill Yellow-legged Frog 4-1 4.1.2 Non-target Species 4-21 4.2 Habitat Assessments and Transects 4-30 4.2.1 Site BC-I 4-30 4.2.2 Site BC-2 4-32 4.2.3 Site BC-3 4-33 4.2.4 Site BC-4 4-35 4.2.5 Site BC-6 4-36 4.2.6 Site BC-7 4-37 4.2.7 Site BC-8 4-39 4.2.8 Site BC-12 4-41 4.2.9 Site WBFR-1 4-42 4.2.10 Site WBFR-2 4-44 5.0 Discussion 5-1 5.1 2025 Survey Results 5-1 5.2 Spatial and Temporal Population Demographic Variability 5-2 6.0 References 6-1 LIST OF APPENDICES Appendix A Flow and Water Temperature Data Appendix B Non-target Species Observations Appendix C Photographs of Survey Sites Appendix D Foothill Yellow-legged Frog Count Data Across Survey Years Appendix E American Bullfrog Count Data Across Survey Years Table of Contents March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 I l in & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 LIST OF TABLES Table 2-1. Butte Creek and West Branch Feather River foothill yellow-legged frog survey sites, 2025 2-2 Table 4-1. Butte Creek and West Branch Feather River foothill yellow-legged frog visual encounter survey data, 2025. 4-1 Table 4-2. Number of foothill yellow-legged frogs observed by life stage during surveys on Butte Creek and the West Branch Feather River, 2025 4-4 Table 4-3. Number of adult foothill yellow-legged frogs observed by sex during surveys on Butte Creek and the West Branch Feather River, 2025 4-6 Table 4-4. Estimated earliest foothill yellow-legged frog egg-laying dates at monitoring sites with observed egg masses, 2025. 4-20 Table 4-5. Non-target herpetofaunaa species observed during surveys on Butte Creek and the West Branch Feather River, 2025. 4-22 Table 4-6. Number of American bullfrogs observed by life stage during surveys on Butte Creek and the West Branch Feather River, 2025. 4-23 LIST OF FIGURES Figure 2-1. Butte Creek and West Branch Feather River foothill yellow-legged frog monitoring area, 2025. 2-3 Figure 4-1. Foothill yellow-legged frog observation locations at Site BC-1, 2025. 4-8 Figure 4-2. Foothill yellow-legged frog observation locations at Site BC-2, 2025. 4-9 Figure 4-3. Foothill yellow-legged frog observation locations at Site BC-3, 2025. 4-10 Figure 4-4. Foothill yellow-legged frog observation locations at Site BC-4, 2025. 4-11 Figure 4-5. Foothill yellow-legged frog observation locations at Site BC-6, 2025. 4-12 Figure 4-6. Foothill yellow-legged frog observation locations at Site BC-7, 2025. 4-13 Figure 4-7. Foothill yellow-legged frog observation locations at Site BC-8, 2025. 4-14 Figure 4-8. Foothill yellow-legged frog observation locations at Site BC-12, 2025. 4-15 Figure 4-9. Foothill yellow-legged frog observation locations at Site WBFR-1, 2025. 4-16 Table of Contents ii March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 in Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-10. Foothill yellow-legged frog observation locations at Site WBFR-2, 2025. 4-17 Figure 4-11. Foothill yellow-legged frog egg masses observed at Site WBFR-1 on June 2 and WBFR-2 on June 2, 2025 4-18 Figure 4-12. Foothill yellow-legged frog tadpoles observed at Site BC-2 on June 2 and BC-12 on September 23, 2025 4-18 Figure 4-13. Young-of-year foothill yellow-legged frogs observed at Site WBFR-1 on August 25 and BC-8 on August 26, 2025. 4-18 Figure 4-14. Subadult foothill yellow-legged frogs observed at Site BC-7 on May 20 and BC-4 on September 25, 2025. 4-19 Figure 4-15. Adult foothill yellow-legged frogs observed at Site BC-2 on May 6 and WBFR-2 on September 25, 2025. 4-19 Figure 4-16. Gravid adult female foothill yellow-legged frogs observed at Site BC-3 on May 6 and BC-12 on May 20, 2025. 4-19 Figure 4-17. Bullfrog observation locations at Site BC-1, 2025. 4-25 Figure 4-18. Bullfrog observation locations at Site BC-2, 2025. 4-26 Figure 4-19. Bullfrog observation locations at Site BC-3, 2025. 4-27 Figure 4-20. Bullfrog observation locations at Site BC-4, 2025. 4-28 Figure 4-21. Bullfrog observation locations at Site BC-6, 2025. 4-29 Figure 4-22. Gravid adult female bullfrog observed at Site BC-6 on May 7 and bullfrog tadpoles observed in same backwater pool on September 24, 2025 4-30 Habitat assessment transect at Site BC-1, looking toward river right, September 24, 2025. 4-31 Habitat assessment transect at Site BC-2, looking toward river left, September 24, 2025. 4-33 Habitat assessment transect at Site BC-3, looking toward river left, September 22, 2025. 4-34 Habitat assessment transect at Site BC-4, looking toward river left, September 25, 2025. 4-36 Habitat assessment transect at Site BC-6, looking toward river right, September 24, 2025. 4-37 Figure 4-23. Figure 4-24. Figure 4-25. Figure 4-26. Figure 4-27. Table of Contents iii March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Fig Butte Creek Foothill Yellow-legged Frog Monitoring 2025 I Figure 4-28. Figure 4-29. Figure 4-30. Figure 4-31. Figure 4-32. Habitat assessment transect at Site BC-7, looking toward river right, September 24, 2025. 4-39 September 23, 2025. 4-40 September 23, 2025. 4-42 September 26, 2025. 4-43 September 25, 2025. 4-45 LIST OF ACRONYMS AND ABBREVIATIONS Habitat assessment transect at Site BC-8, looking toward river left, Habitat assessment transect at Site BC-12, looking toward river left, Habitat assessment transect at Site WBFR-1, looking toward river left, Habitat assessment transect at Site WBFR-2, looking toward river left, °C CDFW cfs GPS FERC FYLF m PG&E Study Plan SUL USFWS UTM VES WBFR YOY degrees Celsius California Department of Fish and Wildlife cubic feet per second global positioning system Federal Energy Regulatory Commission foothill yellow-legged frog meter Pacific Gas and Electric Company Foothill Yellow-legged Frog Study Plan: Butte Creek 2025-2028 snout-urostyle length U.S. Fish and Wildlife Service Universal Transverse Mercator visual encounter survey West Branch Feather River young-of-year Table of Contents iv March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 r& i Butte Creek Foothill Yellow-legged Frog Monitoring 2025 EXECUTIVE SUMMARY This report describes the results of the 2025 monitoring program for foothill yellow-legged frog (FYLF; Rana boylii) on Butte Creek and the West Branch Feather River (WBFR), conducted by Pacific Gas and Electric Company and Stillwater Sciences. The monitoring was initiated in response to the Butte Canal breach and associated debris flow that occurred in August 2023, which introduced sediment into Butte Creek and raised concerns about potential impacts on aquatic habitats and sensitive species. Surveys were conducted from May through September 2025 at eight representative sites on Butte Creek and two control sites on the WBFR. The study employed visual encounter surveys and habitat assessments, building on previous efforts in 2023 and 2024, and referencing historical data from the 2006 relicensing studies (PG&E 2008). The 2025 effort expanded the spatial scope and incorporated early-season egg mass surveys to better capture breeding activity and recruitment success. Key findings indicate that a robust FYLF population persists in Butte Creek, defined here as supporting all life stages as well as breeding and recruitment across most sites with a substantial number of egg masses observed. Biologist observed all life stages—egg masses, tadpoles, young- of-year (YOY), subadults, and adults—in Butte Creek, as well as successful breeding and recruitment at six of the eight sites. A total of 103 individual egg masses were documented across all Butte Creek sites (including larvae clusters observed during the first survey of the year that indicated a recently hatched egg mass). The WBFR control sites provided useful context. While the WBFR sites had higher numbers of YOY, subadults, and adults in 2025, Butte Creek sites exhibited greater tadpole and egg mass counts at certain locations. These patterns likely reflect a combination of habitat quality, hydrologic conditions, and the influence of non-native predators such as bullfrogs, which remain absent from the WBFR but have expanded their range upstream in Butte Creek. Overall, the preliminary study results to date do not suggest a declining or unstable FYLF population in Butte Creek, with no current indication of long-term population-level impacts attributable to the 2023 canal breach, recognizing that continued annual monitoring is required to evaluate potential delayed effects. Demographic variability and abundance trends across 2024- 2025 show no discernible population declines, and adult and egg mass numbers in 2025 generally exceeded those observed in 2024 and 2006. Continued annual monitoring, including comparison with control sites and historical data, will be useful for detecting any delayed effects and informing whether adaptive management strategies are needed. Executive Summary v March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 r, . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 1.0 Background On August 10, 2023, Butte Canal, part of Pacific Gas and Electric Company's (PG&E's) DeSabla- Centerville Hydroelectric Project (Federal Energy Regulatory Commission Project [FERC] No. 803), breached. Seepage through the bottom of the canal resulted in the erosion of upland areas between the canal and the Butte Creek channel, and water and debris flowed several hundred feet downhill into Butte Creek. The flow eroded the berm and hillside and deposited sediment and debris into one location in the creek. A sediment plume travelled downstream, throughout Butte Creek, leaving erosional deposits in the slow edgewater margins of the creek. PG&E and Stillwater Sciences initiated a foothill yellow-legged frog (FYLF; Rana boylii) study in fall 2023 to attempt to determine the existing status of recruitment of young-of-year (YOY) FYLF in Butte Creek and assess any injury to or effects on FYLF that may have resulted from the Butte Canal breach (PG&E and Stillwater Sciences 2023). The 2023 study included conducting visual encounter surveys (VESs) and habitat assessments at three survey sites (BC-4, BC-6, and BC-12) in September and October 2023. In 2024, PG&E expanded the FYLF study to conduct four VESs and habitat assessments at 2023 sites and three additional sites along Butte Creek (BC-3, BC-7, and BC-8) to determine the status of reproduction and recruitment, and coarsely compare current distribution and numbers to historical baseline data (i.e., from the 2006 relicensing study [PG&E 2025a]). On November 19, 2024, FERC issued a letter requiring PG&E to coordinate with the U.S. Fish and Wildlife Service (USFWS) and California Department of Fish and Wildlife (CDFW) to conduct an ongoing FYLF population assessment to compare with the 2006 monitoring effort (which represented pre-failure conditions). This included developing a plan for additional FYLF monitoring in Butte Creek and providing contingency for mitigation to the Butte Creek FYLF population if monitoring confirms a significant loss of FYLF from the 2023 failure and associated sediment release. On May 19, 2025, PG&E filed the Foothill Yellow-legged Frog Study Plan: Butte Creek 2025-2028 (Study Plan; PG&E 2025b) with FERC. On August 15, 2025, FERC approved the Study Plan, including requiring that PG&E develop an annual technical monitoring report by January 31 of the year following each monitoring season to provide details about the survey results, a discussion of the habitat assessments, and a comparison of the results with 2006 survey data to determine the effects of the failure on FYLF. The final report under the Study Plan, due to FERC by March 1, 2029, should identify any future mitigation activities, if warranted, and a plan and schedule for completing the mitigation, as well as documentation of agency concurrence in its filing. In 2025, through coordination with USFWS and CDFW and pursuant to the proposed Study Plan (filed with FERC on May 19, 2025), PG&E further expanded the FYLF study to better assess the population and degree of potential effects of the Butte Canal breach on FYLF in Butte Creek. Two more sites were added on Butte Creek—BC-1 and BC-2—as well as two sites on the nearby West Branch Feather River (WBFR) (WBFR-1 and WBFR 2). More early season egg mass surveys were incorporated to better assess the timing and success of breeding onset. The WBFR, which was not impacted by the canal breach, was included as a control to compare against breeding and 1.0 Background 1-1 March 2026 O2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 FA Butte Creek Foothill Yellow-legged Frog Monitoring 2025 recruitment in Butte Creek. The WBFR sites, which were also surveyed as part of relicensing studies performed in 2006, have similar habitat conditions to Butte Creek sites and had observations of all FYLF life stages during 2006 surveys (PG&E 2008). In accordance with FERC reporting requirements, this document describes 2025 survey methods and results, including habitat assessments and transects, and discusses the results of preliminary data analyses and high-level comparisons of the 2023, 2024, and 2025 survey results with the 2006 relicensing study data to inform the assessment of potential long-term impacts of 2023 sediment inputs into Butte Creek. This document also includes an evaluation of any apparent significant loss of the FYLF population that may have occurred during the respective year of surveys as well as comprehensively for all survey years. 1.0 Background 1-2 March 2026 ©2026, Pacific Gas and Electric Company l Document Accession #: 20260309-0002 Filed Date: 03/09/2026 tif3 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 2.0 Monitoring Area The 2025 Butte Creek monitoring area included safely accessible portions of eight sites located downstream of the sediment deposition area across three reaches (Table 2-1, Figure 2-1). These sites are located on PG&E, U.S. Bureau of Land Management, CDFW, Mechoopda Indian Tribe of Chico Rancheria, and private lands in Butte County. All eight sites were surveyed in 2006 during the DeSabla-Centerville relicensing study. Six of these sites (BC-3 to BC-12) were surveyed for FYLF during 2024 surveys, with tadpoles and post-metamorphic frogs observed at each. Sites BC- 1 and BC-2 were excluded from the 2024 monitoring area because no FYLF egg masses or tadpoles were observed at those sites during the 2006 relicensing studies, but were added as survey sites for 2025 at the request of CDFW and USFWS. To avoid areas with unsafe access and/or unsuitable habitat (e.g., long, deep runs or pools), the survey length of Site BC-8 was reduced by half as compared with 2006, and sites BC-1, BC-4, BC-7, and BC-12 show minor differences from 2006 site lengths, presumably because of variations in surveyable site conditions, methodology for measuring site lengths, or both. Lengths were consistent for all sites between 2024 and 2025 surveys. The 2025 West Branch Feather River monitoring area included two survey sites located on Plumas National Forest, U.S. Bureau of Land Management, and private lands in Butte County. These two sites were last surveyed during 2006 relicensing studies (PG&E 2008). 2.0 Monitoring Area 2-1 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 ,tin & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Table 2-1. Butte Creek and West Branch Feather River foothill yellow-legged frog survey sites, 2025. Reach UTM Coordinates" Site Site Lengtha 2025 (miles) Downstream End Upstream End Northing Easting Northing Easting Centerville Powerhouse BC-1 1.7 4396326 607203 4396545 609291 BC-2 1.1 4396661 609334 4397382 610205 BC-3 0.3 4397754 610437 4398155 610735 BC-4 0.6 4403283 614081 4403855 614349 DeSabla Powerhouse BC-6 0.3 4406436 614657 4406726 614927 BC-7 0.4 4407946 615523 4408687 615719 BC-8 0.5 4409779 615827 4410575 615801 Forks of Butte Diversion Dam area BC-12 1.1 4417857 617784 4419247 618446 Upstream of Miocene Diversion WBFR-1 0.3 4408139 622332 4408521 622297 At Jordan Hill Road Bridge WBFR-2 0.3 4409187 622482 4409682 622577 a Site lengths were calculated in geographic information systems (GIS) and rounded to the nearest tenth of a mile (coordinate system: NAD83 UTM Zone 10 North); site lengths may differ from those reported from 2006 studies (PG&E 2008) because of variations in surveyable site conditions, methodology for measuring site lengths, or a combination of both. b UTM = Universal Transverse Mercator; Coordinate System: NAD83 UTM Zone 10 North, N = Northing, E = Easting 2.0 Monitoring Area 2-2 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 BC-12 Forks of Butte Camping Area Doe Mill Rd Bridge °S tirling City Hendricks Head Dam BC-8 BC-7e ' BC-6 Centerville Powerhouse Centerville Rd Bridge BC-4J ) WBFR-2 Ma galia Reservoir i WFR WBFR-1 Magalia ° , ya „z as creek Paradise \A(1' 1171 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 FOOTHILL YELLOW-LEGGED FROG STUDY - BUTTE CREEK Rock Cre".* Rock Forest Ranch O Lower Centerville Bw98. Diversion Dam Paradise Lake Creek ea ac 32 BC-3 9 BC-1 BC -2 Yankee Hill0 FYLF Monitoring Area Map Sources: Roads, rivers, cities, Map Location Redding / 2025 survey site Lake/reservoir waterbodies: ESRI 2016 Hilshade: USGS A Landmark Perennial stream Chester' •Flow gage Intermittent stream Chico L\ Temperature monitoring station Infrastructure 0 0.75 1.5 3 10lorneers •Butte Canal Sediment Input Area 99 0 0.5 1 2 Miles Sttlbcater Scietweti Figure 2-1. Butte Creek and West Branch Feather River foothill yellow-legged frog monitoring area, 2025. 2.0 Monitoring Area 2-3 March 2026 ©2026, Pacific Gas and Electric Company 70 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 r& Butte Creek Foothill Yellow-legged Frog Monitoring 2025 3.0 Methods Population monitoring and habitat assessments were conducted in all safely accessible and permissible areas at each site, as described in the Study Plan (PG&E 2025b) and based on procedures described in PG&E's monitoring protocol titled A Standardized Approach for Habitat Assessments and Visual Encounter Surveys for the Foothill Yellow-legged Frog (Rana boylii) (Seltenrich and Pool 2002, as previously revised). In addition to FYLF, surveyors recorded all other aquatic herpetofauna (amphibians and reptiles) and any potential predators observed. 3.1 Visual Encounter Surveys Teams of two to three surveyors performed four to six sets of VESs at each site. Each survey targeted the following specific FYLF life stages: •Two to four May and June surveys targeting egg masses, •One late August survey targeting tadpoles, and •One final mid-September survey targeting YOY. Four sets of egg mass surveys were conducted at the lowest sites in the reach (BC-2, BC-3, BC-4, and BC-6) because access was feasible during higher flows in early May. Sites BC-1 and WBFR- 2 were also surveyed during early May, but high flows restricted access to only portions of these sites. High flows in early May prevented safe access to remaining sites. Additionally, a road washout prevented early season access to Site BC-8 until June 3. Surveys were conducted by teams of two to three surveyors working in tandem to maximize coverage of potential breeding habitat. During egg mass surveys, one surveyor snorkeled suitable habitat, as safe and feasible. Data collection for FYLF observations included location, life stage, Gosner (1960) stage (where applicable), total length (for tadpoles), depth at observation (for egg masses and tadpoles), perch or attachment substrate, snout-urostyle length (SUL) (for post-meta- morphs), sex (if observable), body condition (e.g., emaciated, injured), dominant riparian type at observation, geomorphic unit type (e.g., riffle, run, pool, side channel) at observation, nearest bank, as well as Universal Transverse Mercator (UTM) coordinates (recorded using tablets equipped with a global positioning system [GPS]). Sex determinations for adult frogs were made in the field based on presence of observable secondary sexual characteristics (e.g., nuptial pads). A frog was characterized as an adult if it measured at least 40 millimeters SUL, or smaller but with apparent secondary sexual characteristics. Groupings of multiple individuals—most commonly tadpoles and YOY—were recorded as an approximate range in meters (m) from an initial GPS waypoint. 3.0 Methods 3-1 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 F, l . , Butte Creek Foothill Yellow-legged Frog Monitoring 2025 3.2 Habitat Assessments and Transects At the end of each survey, general FYLF habitat quality was assessed for the survey site and the following additional information was recorded: air and mid-channel water temperatures; presence of fish, predators, or other aquatic herpetofauna observed; and observable anthropogenic disturbance (i.e., mining, recreation). Photographs were taken of the survey start and end points at the downstream and upstream ends of the site as well as representative habitat throughout the site. At the end of the September survey at each site, surveyors additionally characterized the general habitat across the survey reach by recording the following: geomorphic unit type(s), aquatic substrate composition, vegetation types, percent aquatic cover, percent riparian canopy cover, stream gradient, turbidity, water color, and descriptions of any evidence of mining or recreation observed. To compare potential observable changes in habitat suitability across years (e.g., vegetation encroachment affecting breeding suitability), surveyors conducted finer-scale habitat assessments across one transect per survey site. Previously established transects were re-assessed at the six sites surveyed in 2024, and new transects were established at the four sites added in 2025. New transects were established in suitable breeding habitat and, where feasible, in areas with high concentrations of observed egg masses, tadpoles, and/or YOY FYLF. The following physical characteristics were measured or estimated across each transect: thalweg and edgewater temperatures; geomorphic unit type(s); aquatic substrate composition and substrate embeddedness; wetted width and bankfull width (measured with a rangefinder); turbidity (visual assessment); stream gradient; upland habitat type; presence of aquatic cover and dominant type; percent riparian canopy; dominant canopy species; and percent margin, emergent, and submerged vegetation by type. Active erosion and any anthropogenic impacts on amphibian habitat present adjacent to the transect were also noted. Photographs were taken of each transect from both banks looking toward the middle of the channel, and from mid-channel looking both upstream and downstream. 3.0 Methods 3-2 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 .in & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 4.0 Results 4.1 Visual Encounter Surveys Results of 2025 surveys are provided below for FYLF and for non-target herpetofauna. 4.1.1 Foothill Yellow-legged Frog Biologists conducted VESs on May 5-7, May 19-22, June 2-5, June 16-19, August 25-28, and September 22-26, 2025. Surveys were conducted during favorable weather conditions for amphibian detection (e.g., clear, sunny to partly cloudy skies, minimal wind). General survey condition data are summarized in Table 4-1. Flow and water temperature data from the nearest associated monitoring stations are plotted in Appendix A. Table 4-1. Butte Creek and West Branch Feather River foothill yellow-legged frog visual encounter survey data, 2025. Site Survey Date (2025) Survey Time (HH:MM) Flow (cfs)a Air Temperature (°C) Water Temperature (°C) Start End Mean Start End Start End BC-1 05/07' 09:28 11:46 293 20.3 21.7 12.9 14.3 05/21 09:04 15:30 254 17.0 28.0 14.0 16.5 06/04 09:15 13:31 216 25.0 32.1 18.1 21.8 06/18 09:19 13:22 195 21.0 31.5 16.9 19.6 08/27 09:33 14:02 139 26.4 31.0 20.0 22.8 09/24 09:14 13:24 114 24.0 29.2 16.9 19.3 BC-2 05/06 11:34 16:13 301 27.0 27.8 13.6 15.9 05/19 15:06 18:24 265 29.4 27.1 16.9 16.9 06/04 14:05 17:19 216 31.8 33.2 20.7 22.1 06/18 14:13 16:54 195 30.3 28.9 21.0 21.2 08/27 14:31 17:28 139 31.3 32.5 23.6 24.1 09/24 14:20 17:44 114 28.4 27.8 19.6 19.3 BC-3 05/06 16:47 18:04 301 24.3 26.8 16.1 15.9 05/21 09:15 11:50 254 20.2 23.7 14.1 14.1 06/05 10:20 11:34 211 26.4 24.8 17.8 17.7 06/19 10:10 11:13 191 25.4 25.4 18.4 18.0 08/28 09:23 10:53 134 25.1 24.5 19.0 19.1 09/22 15:36 17:55 117 34.5 34.8 21.2 20.8 4.0 Results 4-1 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 r& . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Site Survey Date (2025) Survey Time (HH:MM) Flow (cfs)a Air Temperature (°C) Water Temperature (°C) Start End Mean Start End Start End BC-4 05/05 17:36 19:30 315 25.7 19.5 14.1 13.3 05/19 15:54 17:51 265 29.1 27.6 15.0 -- 06/05 10:46 12:28 211 26.9 27.1 16.8 17.2 06/19 10:49 12:46 191 27.0 28.0 17.0 18.0 08/28 10:04 12:10 134 26.2 30.2 18.2 19.1 09/25 09:47 13:07 115 24.0 27.1 15.5 16.5 BC-6 05/07 13:09 14:12 293 24.1 25.6 13.4 13.8 05/21 13:51 16:47 254 28.0 24.5 14.1 14.5 06/04 15:04 16:14 216 31.1 21.5 18.2 18.1 06/18 09:27 11:36 195 24.1 28.3 16.1 16.9 08/27 14:43 16:18 139 31.3 29.1 20.5 20.8 09/24 16:04 17:48 114 28.7 22.5 18.3 18.0 BC-7 05/20 10:56 15:24 260 25.0 25.2 13.0 14.8 06/04 10:01 13:22 216 21.5 21.5 15.6 16.9 06/18 13:23 17:27 195 31.1 28.7 17.0 18.1 08/27 10:08 12:45 139 25.2 30.2 18.0 19.2 09/24 10:16 14:11 114 23.0 30.1 15.0 16.6 BC-8c 06/03 10:25 16:57 217 23.5 21.2 15.3 17.0 06/17 09:42 15:10 201 24.0 28.0 13.4 16.2 08/26 10:09 15:14 137 21.4 29.0 18.2 19.1 09/23 10:16 16:45 115 21.3 27.1 15.0 17.8 BC-12 05/20 10:02 17:45 154 17.1 21.5 11.0 13.0 06/03 11:21 16:40 112 26.3 25.7 15.4 17.4 06/17 10:03 16:49 86 20.6 27.5 12.6 16.2 08/26 09:50 15:32 63 20.0 27.9 17.0 18.0 09/23 10:14 15:44 61 16.3 28.0 12.7 13.5 WBFR-1 05/22 10:35 11:52 366 22.0 22.2 11.6 12.1 06/02 15:27 16:59 259 31.7 28.1 18.1 19.4 06/16 14:51 17:25 93 27.5 24.5 17.8 18.1 08/25 15:37 18:24 30 32.3 27.4 23.8 23.2 09/26 09:21 11:57 27 16.3 29.1 16.8 16.6 4.0 Results 4-2 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 l i rl , & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Site Survey Date (2025) Survey Time (HH:MM) Flow (cfs)a Air Temperature (°C) Water Temperature (°C) Start End Mean Start End Start End WBFR-2 05/07b 17:43 18:46 529 21.1 20.8 12.3 12.2 05/22 10:21 12:53 366 22.0 22.0 12.0 12.0 06/02 15:45 20:18 259 30.9 19.5 18.1 17.8 06/16 14:46 17:38 93 30.0 22.2 17.7 17.7 08/25 15:32 18:47 30 36.1 30.5 22.9 21.9 09/25 09:27 16:20 27 21.8 24.3 16.2 17.8 Notes: -- = no data recorded; °C = degrees Celsius; cfs = cubic feet per second, HH:MM = time of day shown in 24-hour format a Flow data are presented as a daily average. Flow data for Butte Creek are from PG&E Gage BW97 (for Site BC- 12) and Gage BW98 (for the other Butte Creek sites) (Figure 2-1); accuracy may be fair to poor for flow values between 150 and 300 cfs. Flow data for the WBFR is from the California Department of Water Resources gage at the WBFR near Magalia, Station ID WFR, located near the Miocene Dam. b Incomplete survey due to access limitations from early season high flows. Site BC-8 was not surveyed during May 19-22 surveys due to inaccessible road conditions. Surveyors found FYLF at all 10 survey sites during the 2025 surveys. The numbers of individuals observed by life stage and sex are provided in Tables 4-2 and 4-3, respectively, and locations of FYLF observations are depicted on maps in Figures 4-1 through 4-10. Representative photographs of FYLF egg masses, tadpoles, and post-metamorphic individuals are provided in Figures 4-11 through 4-16. 4.0 Results 4-3 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 I IIM . & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Table 4-2. Number of foothill yellow-legged frogs observed by life stage during surveys on Butte Creek and the West Branch Feather River, 2025. Site Life Stage Number Observed Visit 1 (5/5-5/7) Visit 2 (5/19-5/22) Visit 3 (6/2-6/5) Visit 4 (6/16-6/19) Visit 5 (8/25-8/28) Visit 6 (9/22-9/26) Totala BC-1 Egg mass 0 0 0 0 0 0 0 Tadpole 0 0 0 0 0 0 0 YOY 0 0 0 0 0 0 0 Subadult 0 1 0 0 0 0 1 Adult 0 0 0 0 0 0 0 BC-2 Egg mass 0 0 0 0 0 0 0 Tadpole 0 0 -650 -75 1 0 -726 YOY 0 0 0 0 20 44 64 Subadult 6 0 6 6 1 4 23 Adult 3 0 1 3 0 1 8 BC-3 Egg mass 0 0 0 0 0 0 0 Tadpole 0 0 0 0 0 0 0 YOY 0 0 0 0 5 8 13 Subadult 0 0 0 0 0 10 10 Adult 2 1 2 1 0 0 6 BC-4 Egg mass 0 0 0 0 0 0 0 Tadpole 0 0 30 -100 0 0 -130 YOY 0 0 0 0 -109 11 -120 Subadult 1 0 0 0 0 2 3 Adult 2 2 1 1 0 0 6 BC-6 Egg mass 0 1 0 0 0 0 1 (1)a Tadpole 0 0 10 0 0 0 10 YOY 0 0 0 0 9 1 10 Subadult 0 0 0 0 0 0 0 Adult 0 3 1 0 1 0 5 BC-7 Egg mass -- 27 [+42]6 0 0 0 0 69 (69) a,b Tadpole -- —15,720 -12,391 -3,765 -503 6 -32,385 YOY -- 0 0 0 4 17 21 Subadult -- 2 4 0 1 2 9 Adult -- 12' 10 13 5 14 54 4.0 Results 4-4 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 .r & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Site Life Stage Number Observed Visit 1 (5/5-5/7) Visit 2 (5/19-5/22) Visit 3 (6/2-6/5) Visit 4 (6/16-6/19) Visit 5 (8/25-8/28) Visit 6 (9/22-9/26) Totala BC-8 Egg mass -- -- 5 [+18]d 0 0 0 23 (23) a'd Tadpole -- -- —4,795 —2,771 —275 0 -7,841 YOY -- -- 0 0 73 -114 -187 Subadult -- -- 3 0 0 0 3 Adult -- -- 3 2 3 4 12 BC-12 Egg mass -- 7 2 2 0 0 11 (10)a Tadpole -- 0 -1,000 -2,2 35 6 1 -3,242 YOY -- 0 0 0 4 17 21 Subadult -- 2 0 1 1 • I 5 Adult -- 7 6' 5 6 1 25 WBFR-1 Egg mass -- 0 5 3 0 0 8 (8)a Tadpole -- 0 0 -600 67f 3 -670 YOY -- 0 0 0 64g -559 -623 Subadult -- I 2 10 5 1 19 Adult -- 0 3 2 0 4 9 WBFR-2 Egg mass 0 3 38" 1 0 0 42 (39)a Tadpole 0 0 0 -2,425 -184 38 -2,647 YOY 0 0 0 0 —96 —677' —773 Subadult 5 12 15 12 29 12 85 Adult 5 11 17 5 23 66 127 Notes: — = approximately; -- = no data (not surveyed); YOY = young-of-year a Because the same individuals may have been observed on separate visits, totals may exceed the true number of individuals present; however, exact counts are known for egg masses and provided in parentheses. •Of the 27 unhatched egg masses observed, one was in the mainstem, and 26 were in backwater pools with varying degrees of connectivity to the mainstem (most were disconnected or partially connected). An additional 42 newly hatched egg masses (observed as larvae clusters and included in tadpole counts) were also observed within these backwater pools during the first survey, and are included in the total egg mass count because they indicate known egg masses laid prior to the first survey. c Of these, two frogs were found deceased during this survey (causes of mortality unknown), one of which was being consumed by a northwestern pond turtle. d An additional 18 newly hatched egg masses (observed as larvae clusters and included in tadpole counts) were observed during the first survey. They are included in the total egg mass count because they indicate known egg masses laid prior to the first survey. e Of these, one frog was found deceased during this survey (cause of mortality unknown), with an egg mass partially emerged from its cloaca. f Of these, five tadpoles were found deceased during this survey (causes of mortality unknown). g Of these, one YOY was found deceased during this survey (cause of mortality unknown). An additional egg mass was observed above the water line and desiccated during this survey. Of these, one YOY was found deceased during this survey (cause of mortality unknown). 4.0 Results 4-5 March 2026 ©2026, Pacific Gas and Electric Company • Document Accession #: 20260309-0002 Filed Date: 03/09/2026 RA Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Table 4-3. Number of adult foothill yellow-legged frogs observed by sex during surveys on Butte Creek and the West Branch Feather River, 2025. Site Sex Number Observed Visit 1 (5/5-5/7) Visit 2 (5/19-5/22) Visit 3 (6/2-6/5) Visit 4 (6/16-6/19) Visit 5 (8/25-8/28) Visit 6 (9/22-9/26) Totals BC-1 Male 0 0 0 0 0 0 0 Female 0 0 0 0 0 0 0 Unknown 0 0 0 0 0 0 0 BC-2 Male 3 0 0 2 0 1 6 Female 0 0 0 1 0 0 1 Unknown 0 0 I 0 0 0 1 BC-3 Male 1 0 2 0 0 0 3 Female 1 1 0 0 0 0 2 Unknown 0 0 0 1 0 0 1 BC-4 Male 1 1 1 1 0 0 4 Female 0 1 0 0 0 0 1 Unknown 1 0 0 0 0 0 1 BC-6 Male 0 3 0 0 0 0 3 Female 0 0 0 0 1 0 1 Unknown 0 0 1 0 0 0 1 BC-7 Male -- 2 3 9 2 6 22 Female -- 2 1 1 1 2 7 Unknown -- 8b 6 3 2 6 25 BC-8 Male -- -- 1 0 0 1 2 Female -- -- 1 0 1 3 5 Unknown -- -- 1 2 2 0 5 BC-12 Male -- 2 2 2 2 1 9 Female -- 4 4' 2 2 0 12 Unknown -- 1 0 1 2 0 4 4.0 Results 4-6 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 .Fl & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Site Sex Number Observed Visit 1 (5/5-5/7) Visit 2 (5/19-5/22) Visit 3 (6/2-6/5) Visit 4 (6/16-6/19) Visit 5 (8/25-8/28) Visit 6 (9/22-9/26) Total* WBFR-1 Male -- 0 3 2 0 3 8 Female -- 0 0 0 0 1 1 Unknown -- 0 0 0 0 0 0 WBFR-2 Male 4 4 5 0 3 18 34 Female 0 2 8 1 7 17 35 Unknown 1 5 4 4 13 31 58 a Because the same individuals may have been observed on separate visits, totals may exceed the true number of individuals present. b Of these, two frogs were found deceased during this survey (causes of mortality unknown), one of which was being consumed by a northwestern pond turtle. Of these, one frog was found deceased during this survey (cause of mortality unknown), with an egg mass partially emerged from its cloaca. 4.0 Results 4-7 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 .r & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 FYLF Observations 2025: BC-1 Map Sources: Roads, cities, rivers: ESRI 2016 Map Location n Adult(s) or sub-adult(s) 7, Habitat assessment transect Streams: NHD HR Plus 2020 Imagery: NAIP 2024 E BC-12 nr WBFR-2 FYLF survey site C-7 WBFR-1 BC-6 Intermittent stream BC-4 100 200 400 Meters Chico BC-3 1\, Canal/Ditch FIBC-2 BC-1 II I 250 1000 Feet Stillwater Sciences Figure 4-1. Foothill yellow-legged frog observation locations at Site BC-1, 2025. 4.0 Results 4-8 March 2026 ©2026, Pacific Gas and Electric Company p Document Accession #: 20260309-0002 Filed Date: 03/09/2026 7:6 70 " t 140 Meters 125 250 500 Feet 5ti11watcr Scienc FOOTHILL YELLOW-LEGGED FROG STUDY - BUTTE CREEK FYLF Observations 2025: BC-2 0 Tadpole(s) / Habitat assessment Young-of-year transect (individual or group) / FYLF survey site n Adult(s) or sub-adult(s) E: Adjacent site Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Plus 2020 Imagery: NAIP 2024 Map Location cBC-B BC-7 . , =,BC-6 P. Eic-4 BC-3 BC-1! Fl Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-2. Foothill yellow-legged frog observation locations at Site BC-2, 2025. 4.0 Results 4-9 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Map Location Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Pius 2020 Imagery: NAIP 2024 0 20 40 , SO meters I 60 120 2140 FYLF Observations 2025: BC-3 Young-of-year / Habitat assessment (individual or group) transect Adult(s) or sub-adult(s) FYLF survey site FOOTHILL YELLOW-LEGGED FROG STUDY - BUTTE CREEK .Fill a Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-3. Foothill yellow-legged frog observation locations at Site BC-3, 2025. 4.0 Results 4-10 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 20 40 60 120 80 Metes 1111 I I 240 Peet Stillwater Scient FOOTHILL YELL0':!-LEC,GED FROG STUDY - BUTTE CREEK 0 Tadpole(s) Young-of-year (individual or group) •Adult(s) or sub-adult(s) Habitat assessment transect FYLF survey site Intermittent stream Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Plus 2020 Imagery: NAIP 2024 Map Location OBC-12 WBFR-2 48c-a „ Bt-7 e WBFR-1 .BC-6" '3 •8C-4 o Bt -3 9 BC-2 j FYLF Observations 2025: BC-4 r& Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-4. Foothill yellow-legged frog observation locations at Site BC-4, 2025. 4.0 Results 4-11 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Habitat assessment transect FYLF Observations 2025: BC-6 •Egg mass(es) O Tadpole(s) a 11C-e, FOOTHILL YELLOW-LEGGED FROG STUDY - BUTTE CREEK •lb,ir let / FYLF survey site o (individual Yur? -o fr o a r r group) n Adult(s) or sub-adult(s) Map Sources: Roads, cities, rivers: ESR1 2016 Streams: NHD HR Pius 2020 Imagery: NAIP 2024 20 40 1 0 Meters 60 120 2 140 Feet Intermittent stream Map Location O8C-12 ( 4sc-iNVBFR-2 BC-70 WBFR- 1 t. BC-6 t.1 ,d BC-4 •";.. BC-3 .1 BC-1j J1100 .tn & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-5. Foothill yellow-legged frog observation locations at Site BC-6, 2025. 4.0 Results 4-12 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 FYLF Observations 2025: BC-7 Map Sources: Roads, cities, rivers: ESRI 2016 •Egg mass(es) o Tadpole(s) / Habitat assessment transect Streams: NHD HR Plus 2020 Imagery: NAIP 2024 A Young-of-year FYLF survey site (individual or group) Intermittent stream 0 20 40 80 Meters n Adult(s) or sub-adult(s) Canal/Ditch I ty 0 60 120 240 Feet stiuwacet Sdence Map Location L7 BC-12 .WBFR- 2 BC-7 a WBFR-1 BC-6 BC-4 .r & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-6. Foothill yellow-legged frog observation locations at Site BC-7, 2025. 4.0 Results 4-13 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 FYLF Observations 2025: BC-8 •Egg mass(es) / Habitat assessment Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Plus 2020 0 Tadpole(s) transect Imagery: NAIP 2024 A Young-of-year / FYLF survey site (individual or group) Intermittent stream 0 20 40 40 Meters Adult(s) or sub-adult(s) Canal/Ditch ; I 0 60 120 240Feet 0.nt Map Location pac _.8,WBFR-2 BC-7 r. yVBFR-1 BC-4 BC-3 rsc-2 BC -1 Chico r& Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-7. Foothill yellow-legged frog observation locations at Site BC-8, 2025. 4.0 Results 4-14 March 2026 ©2026, Pacific Gas and Electric Company • Document Accession #: 20260309-0002 Filed Date: 03/09/2026 FYLF survey site Intermittent stream Canal/Ditch •Egg mass(es) o Tadpole(s) •Young-of-year (individual or group) n Adult(s) or sub-adult(s) z Habitat assessment transect FYLF Observations 2025: BC-12 Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Pius 2020 Imagery: NAIP 2024 0 35 70 140 Meters , I I 0 125 250 WO Feet Stillwater Selene Map Location K-12 WBFR-2 BC-7 6 tWBFR-1 BC-6 3 Pik:4 BC-1 r& i Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-8. Foothill yellow-legged frog observation locations at Site BC-12, 2025. 4.0 Results 4-15 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 •Egg mass(es) o Tadpole(s) Young-of-year (individual or group) •Adult(s) or sub-adult(s) Habitat assessment ' transect FYLF survey site Intermittent stream Canal/Ditch Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Plus 2020 Imagery: NAIP 2024 20 49 BO Meters 60 129 240 Feet Stillwater fence BC-12 ac-Ei ,,,WBFR" 2 SC-70 ,ayl‘BFR-1 BC:6 0 86-4 BC-3 BC-2 BC-1: FYLF Observations 2025: WBFR-1 r& Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-9. Foothill yellow-legged frog observation locations at Site WBFR-1, 2025. 4.0 Results 4-16 March 2026 ©2026, Pacific Gas and Electric Company • Document Accession #: 20260309-0002 Filed Date: 03/09/2026 FOOTHILL YELLOW-LEGGED FROG STUDY - BUTTE CREEK FYLF Observations 2025: WBFR-2 Map Sources: Roads, cities, rivers: ESRI 2016 • Egg mass(es) / Habitat assessment Streams: NHD HR Plus 2020 0 Tadpole(s) transect Imagery: NAIP 2024 Young-of-year / FYLF survey site (individual or group) Intermittent stream 0 20 ,0 00 Meters 1 • Adult(s) or sub-adult(s) ' I I 0 60 1120 240 Fee St illwa 00 Sc ion Map Location WBFR-2 BC-7 , fwBFR-1 BC-3 , BC -2 SCA` til & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-10. Foothill yellow-legged frog observation locations at Site WBFR-2, 2025. 4.0 Results 4-17 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 ,tn & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-11. Foothill yellow-legged frog egg masses observed at Site WBFR-1 on June 2 (left) and WBFR-2 on June 2 (right), 2025. Figure 4-12. Foothill yellow-legged frog tadpoles observed at Site BC-2 on June 2 (left) and BC-12 on September 23 (right), 2025. Figure 4-13. Young-of-year foothill yellow-legged frogs observed at Site WBFR-1 on August 25 (left) and BC-8 on August 26 (right), 2025. 4.0 Results 4-18 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 ri& Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-14. Subadult foothill yellow-legged frogs observed at Site BC-7 on May 20 (left) and BC-4 on September 25 (right), 2025. Figure 4-15. Adult foothill yellow-legged frogs observed at Site BC-2 on May 6 (left) and WBFR-2 on September 25 (right), 2025. Figure 4-16. Gravid adult female foothill yellow-legged frogs observed at Site BC-3 on May 6 (left) and BC-12 on May 20 (right), 2025. 4.0 Results 4-19 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 !n & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 The estimated FYLF oviposition period in 2025 was between April 29 and June 17 for the Butte Creek sites, and between May 8 and June 16 for the WBFR sites; these periods are depicted in Appendix A alongside flows and water temperatures. The earliest egg-laying dates were estimated for each site using the date of the first egg mass observed, Gosner stage 1, in situ water temperature data, and approximate development rates from scientific literature and comparable studies (PG&E 2003; GANDA 2020; Wheeler et al. 2014; PG&E and Stillwater Sciences, unpubl. data). Estimated earliest egg-laying dates are presented in Table 4-4 as ranges to account for variation in developmental rates, which may be influenced by locality, temperature, and other environmental factors (Catenazzi and Kupferberg 2017, Zweifel 1955). For example, egg mass development is generally faster at warmer temperatures (Kupferberg et al. 2011). Notably, most of the 42 recently hatched egg masses observed during the May 20 survey at BC-7 were found in completely disconnected backwater pools where water temperatures were substantially higher than mainstem Butte Creek (the remaining recently hatched egg masses were found in partially connected pools with water temperatures closer to the mainstem). The estimated end dates of the FYLF oviposition periods shown in Appendix A are the last date when a new egg mass was observed. Table 4-4. Estimated earliest foothill yellow-legged frog egg-laying dates at monitoring sites with observed egg masses, 2025. Site Date of First Egg Mass Observation (2025) Latest Gosner Stage Observed In situ Water re Temperatu at Egg Mass (°C) Estimated Weeks Since Oviposition Estimated Earliest Egg-laying Date (2025) BC-6 05/21 22 16.5 1 -3 4/30 to 5/12 BC-7 05/20 20-25a 23.4-30.6 1-3 4/29 to 5/13 BC-8 06/03 20-25a 16.8 2-4 5/2 to 5/14 BC-12 05/20 18-19 11.8 1-2 5/5 to 5/12 WBFR-1 06/02 18 -- 1-2 5/18 to 5/25 WBFR-2 05/22 20-25 -- 1-2 5/8 to 5/13 Notes: -- = no data recorded a Hatching or recently hatched egg masses, generally associated with Gosner stages 20-25. If more than one egg mass was found at a site, the furthest developed—or recently hatched—egg mass was used to back-date egg-laying. 4.0 Results 4-20 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 l ir . & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 4.1.2 Non-target Species Non-target herpetofauna observed during surveys are included in Table 4-5. Representative photographs are included in Appendix B. Non-native predatory American bullfrogs (Lithobates catesbeianus) were prevalent along the lower Butte Creek sites, having been observed at Sites BC-1, BC-2, BC-3, BC-4, and BC-6. Table 4-6 summarizes the numbers of each bullfrog life stage observed at each site, Figures 4-17 through 4-21 provide maps showing bullfrog locations, and Figure 4-22 shows representative photographs of an adult and tadpoles. No bullfrogs were observed at the WBFR sites. All bullfrog observation data were entered into CDFW's Bullfrog Observation Collection Form (American Bullfrog Observation Report) to be used as part of statewide bullfrog monitoring. Other non-native predators observed incidentally during surveys include non-native fish species (observed at all sites) and crayfish (Pacifastacus spp.) (observed only at Butte Creek sites). Known native predators of FYLF observed include all three species of garter snake (Thamnophis couchii, Thamnophis elegans elegans, and Thamnophis sirtalisfitchi) and Sierra newt (Taricha sierrae). Notably, surveyors observed an adult Sierra newt predating a FYLF egg mass at Site WBFR-1 on June 8, 2025 (Appendix B, Figure B-2). Northwestern pond turtles (Actinemys marmorata) were consistently observed at Sites BC-1, BC- 2, BC-3, BC-6, and BC-7, including at least one YOY at each of these sites during early season surveys. Surveyors observed an adult northwestern pond turtle feeding on a deceased adult FYLF at Site BC-7 on May 20, 2025. It is unclear if this was predation or scavenging, as the frog's cause of mortality is unknown. Northwestern pond turtles are dietary generalists and frequently consume carrion (Holland 1985), though they have also been known to eat other anuran species opportunistically (Bury 1986, Hays et al. 1999). Native fish species observed during surveys included Sacramento pikeminnow (Ptychocheilus grandis) and rainbow trout (Oncorhynchus mykiss), documented predators of other ranid or anuran species (Brown and Moyle 1997, Vredenburg 2004). 4.0 Results 4-21 March 2026 O2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Ti Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Table 4-5. Non-target herpetofaunaa species observed during surveys on Butte Creek and the West Branch Feather River, 2025. Site Life Stage (E = egg/ egg mass, T = tadpole/larvae, Y = young-of-year, A = adult/juvenile, U = unknown) Sierra newt (Taricha sierrae) Sierran treefrog (Pseudacris sierra) California toad (Anaxyrus boreas halophilus) American bullfrog (Lithobates catesbeianus) Northwestern pond turtle (Actinemys marmorata) Sierra garter snake (Thamnophis couchii) Mountain garter snake (Thamnophis elegans elegans) Valley garter snake (Thamnophis sirtalis fitchi) BC-1 -- Y, A -- T, A Y, A A -- -- BC-2 -- Y E, A T, A Y, U A -- -- BC-3 E T T, Y T, A Y, A -- -- -- BC-4 E Y, A E, T, Y T, A -- -- -- -- BC-6 E, A Y, A -- T, A Y, A A -- -- BC-7 E, A T T, Y -- Y, A A A -- BC-8 E, A T, A -- -- -- A A A BC-12 E, T, A T, A -- -- -- A -- -- WBFR-I E, T, Y, A T, A -- -- -- A -- -- WBFR-2 E, A -- -- -- -- A -- -- Notes: -- = not observed ' The following terrestrial reptiles were observed at various life stages during one or more surveys but not consistently counted: California whiptail (Aspidoscelis tigris munda), northern alligator lizard (Elgaria coerulea), northwestern skink (Plestiodon skiltonianus skiltonianus), northwestern fence lizard (Sceloporus occidentalis occidentalis), western sagebrush lizard (Sceloporus graciosus gracilis), western yellow-bellied racer (Coluber constrictor mormon), California striped racer (Masticophis lateralis lateralis), Northern Pacific rattlesnake (Crotalus oreganus oreganus), California mountain kingsnake (Lampropeltis zonata), and Pacific gopher snake (Pituophis catenifer catenifer). 4.0 Results 4-22 March 2026 ©2025, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 .Fl & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Table 4-6. Number of American bullfrogs observed by life stage during surveys on Butte Creek and the West Branch Feather River, 2025. Site Life Stage Number Observed Visit 1 (5/5-5/7) Visit 2 (5/19-5/22) Visit 3 (6/2-6/5) Visit 4 (6/16-6/19) Visit 5 (8/25-8/28) Visit 6 (9/22-9/26) Total' BC-1 Egg mass 0 0 0 0 0 0 0 Tadpole 3 1 5 4 —200 -668 -881 Adult/Subadult 0 7 3 11 3 4 28 BC-2 Egg mass 0 0 0 0 0 0 0 Tadpole —155 21 40 26 0 -220 -462 Adult/Subadult 0 6 2 1 0 3 12 BC-3 Egg mass 0 0 0 0 0 0 0 Tadpole —510 -2,000 -150 -170 -800 -610 -4,240 Adult/Subadult 1 5 3 2 0 0 11 BC-4 Egg mass 0 0 0 0 0 0 0 Tadpole 0 0 0 0 -320 0 -320 Adult/Subadult 0 0 0 0 1 1 2 BC-6 Egg mass 0 0 0 0 0 0 0 Tadpole 0 0 0 -66 -1,000 -760 -1,826 Adult/Subadult 1 3 0 2 0 1 7 BC-7 Egg mass -- 0 0 0 0 0 0 Tadpole -- 0 0 0 0 0 0 Adult/Subadult -- 0 0 0 0 0 0 BC-8 Egg mass -- -- 0 0 0 0 0 Tadpole -- -- 0 0 0 0 0 Adult/Subadult -- -- 0 0 0 0 0 BC-12 Egg mass -- 0 0 0 0 0 0 Tadpole -- 0 0 0 0 0 0 Adult/Subadult -- 0 0 0 0 0 0 WBFR-1 Egg mass -- 0 0 0 0 0 0 Tadpole -- 0 0 0 0 0 0 Adult/Subadult -- 0 0 0 0 0 0 4.0 Results 4-23 March 2026 ©2025, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Frji Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Site Life Stage Number Observed Visit 1 (5/5-5/7) Visit 2 (5/19-5/22) Visit 3 (6/2-6/5) Visit 4 (6/16-6/19) Visit 5 (8/25—8/28) Visit 6 (9/22-9/26) Totals W B FR-2 Egg mass 0 0 0 0 0 0 0 Tadpole 0 0 0 0 0 0 0 Adult/Subadult 0 0 0 0 0 0 0 Notes: — = approximately; -- = no data (not surveyed) a Because the same individuals may have been observed on separate visits, totals may exceed the actual number of individuals present. 4.0 Results 4-24 March 2026 ©2025, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Bullfrog Observations 2025: BC-1 0 Tadpole(s) FYLF survey site n Adult(s) or sub-adult(s) Intermittent stream Canal/Ditch Adjacent site Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Plus 2020 Imagery: NAIP 2024 O 75 150 300 Meters I I'll] 250 500 1000 Feet Map Location L-. BC-12 LBC-B WBFR-2 , BC-7:: a .WBFR-1 BC-6 BC-4 .7 BC-3 BC-2 BC-1 ill once Ir& Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-17. Bullfrog observation locations at Site BC-1, 2025. 4.0 Results 4-25 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Fll& Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Bullfrog Observations 2025: BC-2 0 Tadpole(s) FYLF survey site n Adult(s) or sub-adult(s) Adjacent site Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Pius 2020 Imagery: NAIP 2024 o 20 40 80 Meets I • ,i , I O 60 120 240 Feet Stillwatrr Science, WBER-2 8C-7d f WBFR-1 / / BC:* '.BC-4 BC-3 BC-2 BC-V Figure 4-18. Bullfrog observation locations at Site BC-2, 2025. 4.0 Results 4-26 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 20 40 60 120 BC-3 I I al 9 C-2 BC-1 00 Meters 2140 Feet Stillwater Sciences FOOTHILL YELLOW-LEGGED FROG STUDY - BUTTE CREEK Bullfrog Observations 2025: BC-3 O Tadpole(s) FYLF survey site n Adult(s) or sub-adult(s) Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Plus 2020 Imagery: NAIP 2024 Map Location -BC-12 t WBFR-2 BC-8 - BC-7 c vsIBFR-1 BC-6 BC-4 0 kF! 8 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-19. Bullfrog observation locations at Site BC-3, 2025. 4.0 Results 4-27 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Bullfrog Observations 2025: BC-4 0 Tadpole(s) FYLF survey site n Adult(s) or sub-adult(s) Intermittent stream Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Plus 2020 Imagery: NAIP 2024 0 20 40 8i) Meters I tit 60 120 Stillwater Scic Twos Map Location 0,4 ' CBC-B ;BC-7P WBFR-1 "BC-6 (7,>. lieT4 BC-3 BC-2„' BC-1: Z4-; 99., ,tiri & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-20. Bullfrog observation locations at Site BC-4, 2025. 4.0 Results 4-28 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Bullfrog Observations 2025: BC-6 o Tadpole(s) FYLF survey site •Adult(s) or sub-adult(s) Intermittent stream Map Sources: Roads, cities, rivers: ESRI 2016 Streams: NHD HR Plus 2020 Imagery: NAIP 2024 20 40 00 Meters I lilt I I' ' 0 60 120 240 Feet Still. ate.' Sciences Map Location [7 BC-12 LBC-8 WBFR-2 2 BC-7: *BC-6 WBFR-1 BC-4 co BC-3 Eff3C-2 BC-1 7Z. r& , Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-21. Bullfrog observation locations at Site BC-6, 2025. 4.0 Results 4-29 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 l i n . & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-22. Gravid adult female bullfrog observed at Site BC-6 on May 7 (left) and bullfrog tadpoles observed in same backwater pool on September 24 (right), 2025. 4.2 Habitat Assessments and Transects Habitat assessment summaries for each survey site and each site transect are provided in the following sections, and representative photographs of habitat at each site are included in Appendix C. Site-wide and transect habitat assessments were conducted at each site during the September 2025 surveys. Data collected from established habitat transects showed no evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. Surveyors did not observe any red fine sediment (i.e., similar to what was released during the canal failure) at any site during 2025 (or 2024) surveys. 4.2.1 Site BC-1 Site BC-1 generally had poor-quality habitat for FYLF, with a few scattered areas of higher quality habitat (e.g., cobble bars). The survey site was low gradient and primarily consisted of approximately 1-m deep run and glide habitats, with some shallow riffles and a few deep mid- channel pools. The site contained a few backwater pools and small side channel habitats, though the presence and location of these varied at different flows. One deep mid-channel pool— approximately 450 m long at the downstream end of the survey reach—was excluded from all surveys as it contained marginal or no FYLF habitat with limited survey access. The dominant substrate throughout the site was cobble, though boulder and pebble were also common, and both sand and silt/mud were present in small patches. A riparian canopy shaded both banks for most of the survey reach, and, on average, shaded over 40 percent of the channel. Recreation and anthropogenic impacts on the channel (such as rock weirs) were observed but were concentrated at a few gravel/cobble bars in the downstream portions of the site. The habitat assessment transect at Site BC-1 was located across a run just upstream of a wide low- gradient riffle. Because so few FYLF were observed at Site BC-1 (one subadult), the transect was placed in an area deemed to have breeding potential, though no FYLF or signs of breeding were observed nearby during surveys (Figure 4-1, Figure 4-23). The wetted channel width was 4.0 Results 4-30 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 PM Butte Creek Foothill Yellow-legged Frog Monitoring 2025 approximately 21 m, and bankfull width was approximately 75 m. The channel across the transect was primarily run habitat (81-100 percent) with a small amount of low-gradient riffle (1-20 percent). Aquatic substrate primarily consisted of moderately embedded cobble (41-60 percent), followed by boulder (21-40 percent) and gravel/pebble (21-40 percent), with small amounts of sand and silt/mud along the left bank (1-20 percent). The right bank was well vegetated with willow (Sal ix spp.), alder (Alnus sp.) and wild grape ( Vitis californica), and the left bank had sparse forbs and willow saplings. Algae, including brown algae, coated much of the substrate across the transect, but no other emergent or in-channel vegetation was present. The transect contained sufficient aquatic cover opportunities, predominantly as gaps between substrate. Overhanging vegetation (willow, wild grape, and alder) shaded the right bank and covered between 1 and 25 percent of the transect. The bank gradient was low on the left bank and high on the right bank; neither bank showed signs of active erosion. The dominant upland habitat was foothill hardwood/conifer and showed signs of recent fire. The water was clear and turbidity was low. While there is only one set of habitat transect data for this site, a qualitative assessment showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. Figure 4-23. Habitat assessment transect (red line) at Site BC-1, looking toward river right, September 24, 2025. 4.0 Results 4-31 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 FA& Butte Creek Foothill Yellow-legged Frog Monitoring 2025 4.2.2 Site BC-2 Site BC-2 generally had moderate quality habitat for FYLF. The survey site consisted of riffle and run habitats with a few small backwater pools throughout, as well as one short (approximately 60-m) and one extensive (approximately 350-m) side channel section. The dominant substrate throughout the reach was cobble, followed by pebble and silt/mud (the latter predominately in slow-moving sections, including the side channels and backwater pools), with boulder and sand also present at the site. Emergent vegetation was present along slower-moving areas of the main channel and in backwater pools. Riparian vegetation grew along both banks and shaded less than 20 percent of the channel throughout the reach. There were a few large, unvegetated cobble bars in the upstream portion of the site, beginning around the downstream end of the extensive side channel. Evidence of recreation was observed throughout the survey reach, including litter and debris, chairs, stacked rock weirs, driftwood structures, cleared vegetation, and compacted soils. Recreators were observed during two out of six surveys. The habitat assessment transect at Site BC-2 was established on the upstream end of a large cobble bar at the upstream extent of the survey site, in an area where many post-metamorphic frogs were found during all surveys and where a cluster of recently hatched tadpoles was found during the June 5,2025 survey (Figure 4-2, Figure 4-24). The stream transect was predominately run (41-60 percent), with low-gradient riffle (21-40 percent) and exposed cobble (1-20 percent) habitats comprising the remainder. The wetted channel width was approximately 19 m, and bankfull width was approximately 51 m. The stream was low gradient at the transect. Aquatic substrate across the transect generally had low embeddedness and consisted of cobble (41-60 percent), pebble (21-40 percent), and silt/mud (21-40 percent), with some boulders and sand. Emergent vegetation (forbs and grasses) grew sparsely on the right bank and densely on the left bank. Dense margin vegetation (consisting of forbs, grasses, willows, alders, and sedges [Carex spp.]) grew along the left bank. The transect contained abundant aquatic cover opportunities, predominantly as gaps between substrate. The riparian canopy and overhanging vegetation along the left bank shaded between 1 and 25 percent of the channel and consisted of blackberry (Rubus sp.), willow, and alder. The bank gradient was low on the right bank and high on the left bank, with signs of active erosion. Upland habitat at the transect was primarily foothill hardwood/conifer and showed signs of recent fire. The water was clear and turbidity was low. While there is only one set of habitat transect data for this site, a qualitative assessment showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. 4.0 Results 4-32 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 tin & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-24. Habitat assessment transect (red line) at Site BC-2, looking toward river left, September 24, 2025. 4.2.3 Site BC-3 Site BC-3 generally had moderate-quality habitat for FYLF. The survey site was dominated by relatively shallow run and riffle habitats in the main channel, with a few backwater pools and side channels throughout. The highest quality FYLF habitat included bedrock pools at the downstream end of the site and a cobble bar in the middle of the survey reach along the right bank. Substrate in the main channel was predominately cobble and pebble, followed by silt/mud (which was primarily associated with the backwater pools and slower moving areas), though boulder, bedrock, and sand were all also present in small quantities. Overhanging riparian vegetation shaded much of the site's margins, and though a riparian canopy was present throughout the entire site, it consistently shaded less than 20 percent of the channel width. Recreation was regularly observed, with swimmers, recreators, and miners present within the survey reach during most surveys. Anthropogenic effects on the channel, such as litter and debris, rock weirs, vegetation clearing, and soil compaction along the banks were also observed. The habitat assessment transect at Site BC-3 was located across a low-gradient riffle (41-60 percent), slow moving side channel (21-40 percent), and dry cobble bar (21-40 percent). Adult and YOY FYLF were found at this cobble bar across most surveys in 2025, and bullfrogs were 4.0 Results 4-33 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 r, . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 observed in the side channel during the September 2025 survey (Figure 4-3, Figure 4-19, Figure 4-25). The wetted channel width was approximately 35 m, and bankfull width was approximately 54 m. Aquatic substrate primarily consisted of loosely embedded cobble (61—80 percent), followed by gravel/pebble (1-20 percent), and silt/mud (1-20 percent), with minimal amounts of boulder and sand. Forbs and grass grew along the right bank as margin vegetation and across the cobble bar as both emergent and margin vegetation. Green algae was recorded as submerged vegetation along the edges of the cobble bar. Overhanging margin vegetation, including wild grape, blackberry, alder, and willow, shaded the right bank. Both banks had a riparian canopy predominately composed of willow and alder, though combined, this canopy shaded less than 25 percent of the stream. The upland habitat was predominately foothill hardwood. The transect offered plentiful aquatic cover opportunities, predominantly as gaps between substrate. The bank gradient was low on the right bank and moderate on the left bank, and both banks showed signs of erosion. The water was clear and turbidity was low. Habitat transect data showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. Figure 4-25. Habitat assessment transect (red line) at Site BC-3, looking toward river left, September 22, 2025. 4.0 Results 4-34 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 4.2.4 Site BC-4 Site BC-4 generally had moderate- to high-quality habitat for FYLF. The survey site consisted of riffle, run, and mid-channel pools, with an extensive side channel and backwater pool complex, including a large cobble bar. Substrate was predominately cobble and boulder, followed by bedrock, pebble, silt/mud, and sand. Emergent vegetation was present along slower-moving areas throughout the site. Overhanging vegetation and a riparian canopy shaded most of both banks and between 21 and 40 percent of the channel overall. There were a few residences adjacent to the survey site with associated human impacts throughout the site, such as patches of bare ground, as well as evidence of vegetation clearing and soil compaction. The habitat assessment transect at Site BC-4 was located on the upstream end of a large cobble bar and backwater complex where YOY, subadult, and adult FYLF were found during most surveys in 2025 (Figure 4-4, Figure 4-26). The transect included an approximate equal proportion of backwater pool/pool tail-out (21-40 percent), low-gradient riffle (21-40), and dry cobble/boulder (21-40 percent) habitats, as well as a short section of run/glide (1-20 percent). The wetted channel was approximately 40 m wide, and the bankfull width was approximately 50 m. The stream gradient at the transect was low. Aquatic substrate primarily consisted of moderately embedded cobble (41-60 percent) and boulder (41-60 percent), with small amounts of pebble (1-20 percent) and silt/mud (1-20 percent). Grasses were the only emergent vegetation across the transect, and margin vegetation included grasses, sedges, willow, alder, blackberry, and wild grape. There was no submerged vegetation. The transect contained abundant aquatic cover opportunities, predominantly as gaps between substrate. The riparian canopy at the site primarily consisted of alder and shaded less than 25 percent of the transect width. The bank gradient was low on both banks, and upland habitat was predominately foothill hardwood/conifer, and had recently burned further upslope from the creek. The water was clear and turbidity was low. Habitat transect data showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. 4.0 Results 4-35 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 91& . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-26. Habitat assessment transect (red line) at Site BC-4, looking toward river left, September 25, 2025. 4.2.5 Site BC-6 Site BC-6 generally had moderate- to high-quality habitat for FYLF. The survey site consisted of low-gradient riffles, deep runs, and mid-channel pools, as well as two notable backwater pools and small side channel areas present at different flows. Substrate was predominately cobble and boulder, with small amounts of pebble, bedrock, silt/mud, and sand. One substantial cobble/boulder bar was present within the site and was associated with one of the backwater pools. Overhanging vegetation and a riparian canopy shaded less than 20 percent of the channels width throughout the site, and submerged vegetation (algae) was present throughout much of the survey reach. One unnamed tributary entered the creek in the upstream portion of the site. The survey site is adjacent to a series of residences, and associated impacts, such as channel manipulation, patches of bare ground, vegetation clearing, and soil compaction were evident along portions of the bank. The habitat assessment transect at Site BC-6 was located at the upstream end of a cobble/boulder bar and associated backwater pool. A FYLF egg mass (and an estimated 1,000 bullfrog tadpoles) were found in this backwater pool in 2025 (Figure 4-5, Figure 4-21, Figure 4-22, Figure 4-27). The wetted channel width and bankfull width were both approximately 30 m. The stream gradient at the transect was moderate and generally characterized as run/glide (41-60 percent), high- 4.0 Results 4-36 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 l i ffl Butte Creek Foothill Yellow-legged Frog Monitoring 2025 gradient riffle (21-40 percent), and backwater pool (1-20 percent), with some dry cobble/boulder (1-20 percent). Aquatic substrate was primarily cobble (41-60 percent) and boulder (41-60 percent), both with moderate embeddedness, though small amounts of pebble, bedrock, and sand were also present. Margin vegetation was primarily willow and alder but also included sedges, blackberry, wild grape, and forbs. No emergent or submerged vegetation was present within the transect. A riparian canopy of alder and willow shaded less than 25 percent of the transect. The transect contained aquatic cover opportunities, predominantly as gaps between substrate. Both banks were steep and showed signs of active erosion. Upland habitat at the transect was foothill hardwood/conifer. The water was clear and turbidity was low. Habitat transect data showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. Figure 4-27. Habitat assessment transect (red line) at Site BC-6, looking toward river right, September 24, 2025. 4.2.6 Site BC-7 Site BC-7 contained moderate-quality habitat for FYLF with pockets of high-quality habitat. The survey site consisted primarily of riffle and run habitats, with some large mid-channel pools (including one deep, 120-m-long pool that was unsafe to access and therefore bypassed). The site also contained a series of backwater pools, some of which were fully disconnected from the main 4.0 Results 4-37 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 r, . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 channel during all visits in 2025, and all of which were fully disconnected by the final egg mass survey on June 18, 2025. These pools contained the highest concentration of FYLF egg masses observed at any site (Figure 4-6), and both freshly laid and hatched egg masses were observed in these pools during the first visit on May 20, 2025. Boulder, bedrock, and cobble were equally predominant throughout the survey reach; small quantities of sand, silt/mud, and pebble were also present. Margin, overhanging riparian, and emergent vegetation were present throughout much of the site, and the riparian canopy generally shaded less than 20 percent of the channel width. One large perennial tributary, one smaller intermittent tributary, and one seep entered the creek within the site. An active mining claim and mining camp are associated with the survey site; related impacts include channel manipulation, increased erosion, and anthropogenic debris within the channel. The habitat assessment transect at Site BC-7 was located across a moderate-gradient riffle in an area where adult FYLF were observed during 2025 surveys, and adjacent to the bedrock pools where high concentrations of egg masses were observed during early-season surveys (Figure 4-6, Figure 4-28). The wetted channel width was approximately 14 m, and bankfull width was 42 m. At the transect the creek was moderate gradient and primarily riffle habitat (81-100 percent), with small amounts of run/glide (1-20 percent) and dry boulder (1-20 percent). Aquatic substrate consisted primarily of boulder (61—80 percent), with low embeddedness as well as small amounts of bedrock, gravel, pebble, and sand (all less than 20 percent). The margin vegetation across the transect was primarily willow and alder, but sedge and forbs were also present. Umbrella plant (Darmerapeltata) and sedges accounted for all emergent vegetation across the transect, and there was submerged vegetation (algae) present. The transect offered aquatic cover opportunities, predominantly as gaps between substrate. The riparian canopy across the transect was primarily willow and shaded less than 25 percent of the transect. The bank gradient was moderate at the right bank and low at the left bank, and both banks showed signs of active erosion. Upland habitat at the transect was foothill hardwood/conifer. The water was clear and turbidity was low. A well- established mining camp is present just upstream of the transect on the left bank, though anthropogenic impacts on the transect due to mining were less than in 2024 (i.e., there was no channel manipulation or debris within the transect in 2025). The right bank of this transect is 15 m away from the largest of the bedrock pools where high concentrations of FYLF egg masses and tadpoles, as well as many adults, were found in 2025 (Figure 4-6). Habitat transect data showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. 4.0 Results 4-38 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 lin, g Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-28. Habitat assessment transect (red line) at Site BC-7, looking toward river right, September 24, 2025. 4.2.7 Site BC-8 Site BC-8 had a variety of habitats for FYLF, including a few areas of high-quality breeding habitat. The downstream portion of the site was generally lower-quality breeding habitat and was characterized by high-gradient riffle and run habitats over bedrock in a channelized, steep canyon. The upstream portion contained areas of high-quality breeding habitat and generally had a wider channel with more side-channel and riffle habitats. Overall, the site was predominantly run and riffle habitats, with some mid-channel pools and few side channels, backwater pools, and associated cobble bars. Substrate was predominately bedrock followed by boulder and cobble, though pebble, sand, and silt/mud were also present. Overhanging riparian and emergent vegetation were present throughout much of the site, and a canopy dominated by willow and alder shaded less than 20 percent of the channel width on average. Woody debris was present throughout the upstream portion of the survey reach. Two tributaries entered the creek within the site. Evidence of mining activity was observed within the survey reach, including erosion and anthropogenic debris within the channel. The habitat assessment transect at Site BC-8 was located across a low-gradient riffle, with a side channel along the right bank and a side channel and small cobble bar on the left bank, in an area 4.0 Results 4-39 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 I . & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 where tadpole and YOY FYLF were found during 2025 surveys and just downstream of an area where several egg masses, thousands of tadpoles, and several YOY were found during 2025 surveys (Figure 4-7, Figure 4-29). The wetted channel width was approximately 38 m, and the bankfull width was approximately 52 m at the transect. The stream gradient at the transect was moderate and consisted of low-gradient riffle (41-60 percent), run (21-40 percent), side channel (1-20 percent), and dry cobble/boulder (1-20 percent) habitats. Aquatic substrate primarily consisted of boulder (61—80 percent) and cobble (21-40 percent), with small amounts of pebble, sand, and silt/mud (all less than 20 percent). Margin vegetation was primarily blackberry and wild grape, but also included sedge, willow, and alder. Umbrella plant and sedge grew as sparse emergent vegetation across the transect. The transect contained aquatic cover opportunities, predominantly as gaps between substrate and woody debris. Overhanging vegetation shaded the far edges of both banks, and willow-dominated riparian canopy shaded less than 25 percent of the channel width. The bank gradient was moderate at both transect ends and signs of erosion were observed on the left bank. Foothill hardwood/conifer was the dominant upland habitat at the transect. The water was clear and turbidity was low. Habitat transect data showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. Figure 4-29. Habitat assessment transect (red line) at Site BC-8, looking toward river left, September 23, 2025. 4.0 Results 4-40 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Frj Butte Creek Foothill Yellow-legged Frog Monitoring 2025 4.2.8 Site BC-12 Site BC-12 contained a variety of habitats for FYLF ranging from poor to high suitability. The site consisted primarily of run and riffle habitats, with some mid-channel and backwater pool areas, a few short cascade sections, and a few large cobble bars. Substrate overall was relatively equal among boulder, bedrock, and cobble. Overhanging riparian and emergent vegetation were present throughout much of the site, and large woody debris was observed sporadically throughout the reach. A mature riparian canopy generally shaded between 21 and 40 percent of the channel width across the survey reach. West Branch Butte Creek entered the mainstem at the top of this site, and six additional unnamed tributaries entered the creek within the site. Moderate to high recreation levels were observed during all surveys, and active gold mining was observed during four out of five surveys. Anthropogenic impacts included the presence of people and pets, erosion and channel alteration from mining, and trash and debris throughout the survey reach. The habitat assessment transect at Site BC-12 was located across a deep run with a small side pool along the right bank, in an area where YOY FYLF were found during the 2023 and 2024 surveys and just downstream of an area where a FYLF egg mass, YOY, and adult FYLF were found in 2025 (Figure 4-8, Figure 4-30). The wetted channel width was approximately 20 m, and bankfull width was 31 m at the transect. The stream gradient at the transect was low and consisted of run (41-60 percent), backwater pool (41-60 percent), and dry boulder/bedrock (1-20 percent) habitats. Aquatic substrate across the transect consisted of relatively equal proportions of cobble (21-40 percent) and pebble (21-40 percent), with boulder, bedrock, and sand each additionally making up between 1-20 percent of the transect. Vegetation at the margins of the transect was primarily sedge but willow, alder, and grasses also occurred. Umbrella plant was the dominant emergent vegetation across the transect with some sedges and forbs. The transect contained aquatic cover opportunities, predominantly as gaps between substrate. Overhanging vegetation and an alder-dominated riparian canopy shaded less than 25 percent of the wetted transect. The left and right bank gradients were high and moderate, respectively, with signs of active bank erosion on the right bank. Upland habitat at the transect consisted of mixed conifer forest. Signs of mining and recreation impacts were observed at the transect. The water was clear and turbidity was low. Habitat transect data showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. 4.0 Results 4-41 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 tr!8 . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-30. Habitat assessment transect (red line) at Site BC-12, looking toward river left, September 23, 2025. 4.2.9 Site WBFR-1 Site WBFR-1 contained several stretches of high-quality habitat for FYLF. Although the site consisted primarily of deep mid-channel pools and long stretches of runs, a few cobble bars—one of which was extensive—associated with riffles provided high-quality habitat and accounted for most of the FYLF observations (across all life stages) at the site. Small, shallow backwater areas associated with these cobble bars were present throughout the survey reach at lower flows. The dominant substrate was cobble followed by pebble and boulder, though sand and bedrock were also present, particularly in the downstream pool and run sections. Overhanging riparian and emergent vegetation were present along most of the site's margins, and a mature riparian canopy shaded the stream edges throughout the site. One unnamed, perennial tributary entered the river on the left bank near the mid-point of the site, and FYLF were observed here during multiple surveys. No recreation or mining impacts were observed in the reach, though recreators were present just downstream of the reach during two out of five surveys. The habitat assessment transect at Site WBFR-1 was established across the upstream end of the cobble bar and associated backwater pools where all five egg masses and most post-metamorphic individuals were found during surveys (Figure 4-9, Figure 4-31). The wetted channel width at the 4.0 Results 4-42 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 F! & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 transect was approximately 29 m, and bankfull width was 53 m. The stream gradient at the transect was low and consisted primarily of backwater pool (41-60 percent) interspersed with dry cobble and boulders (21-40 percent); low-gradient riffle (21-40 percent) was present along the left bank and contained the thalweg and most of the flow. Aquatic substrate was moderately embedded and consisted relatively equally of small boulders (41-60 percent) and cobble (21-40 percent), though bedrock, sand, and silt/mud were also present. Margin vegetation included blackberry, various forbs, and sedges, the latter of which also occurred as emergent vegetation along with umbrella plant. A riparian canopy composed of alder, some willow, and incense cedar (Calocedrus decurrens) shaded less than 25 percent of the transect width. Gaps between substrate, along with woody debris and root wads, offered plentiful opportunities for aquatic cover. The left bank gradient was high and right bank gradient was moderate. Upland habitat at the transect consisted of mixed conifer forest that had recently burned further up slope. The water was clear and turbidity was low. While there is only one set of habitat transect data for this site, a qualitative assessment showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. Figure 4-31. Habitat assessment transect (red line) at Site WBFR-1, looking toward river left, September 26, 2025. 4.0 Results 4-43 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 !IFI Butte Creek Foothill Yellow-legged Frog Monitoring 2025 4.2.10 Site WBFR-2 Site WBFR-2 contained high-quality habitat for FYLF across most of its length and consisted primarily of runs punctuated by high- and low-gradient riffles with a few slower moving mid- channel pools. A few cobble bars were present throughout the survey reach. Of the 42 egg masses observed at the site, 33 were located along the largest cobble bar in the downstream third of the site (Figure 4-10). The co-dominant substrates at the site were cobble, boulder, and bedrock, all of which occurred in similar quantities, though pebble, sand, and silt/mud were also present. Overhanging riparian and emergent vegetation were present along the margins of much of the site, apart from a few barren bedrock areas and the aforementioned cobble bars. A riparian canopy shaded the margins throughout much of the downstream portion of the reach, though on average it shaded less than 20 percent of the stream's width. One seep entered the channel in the downstream third of the reach on the left bank, and post-metamorphic FYLF were observed at this location during the August and September surveys. Recreation and related evidence (i.e., stacked rock weirs) were observed at the site during every survey. Active mining and/or mining impacts were observed throughout the reach but were notably more prevalent in the upstream portion of the reach near a campsite that was occupied during most surveys. The habitat assessment transect at Site WBFR-2 was established at the downstream end of the large cobble bar where most of the egg masses were observed (Figure 4-10, Figure 4-32). The wetted channel width at the transect was 17 m, and the bankfull width was 40 m. The stream gradient at the transect was low and consisted primarily of a mid-channel pool (81-100 percent), with some dry cobble and boulders (1-20 percent) that created a small backwater (1-20 percent) along the left bank. Aquatic substrate had low embeddedness and consisted primarily of cobble (61—80 percent) followed by boulder (21-40 percent), with bedrock, pebble, and sand combining to constitute less than 20 percent of the transect. Margin vegetation was sparse and consisted of a single sedge on the left bank. There was no emergent, submerged, or overhanging vegetation, and no riparian canopy. Gaps between substrate offered many opportunities for aquatic cover. The bank gradient was low on the right bank along the cobble bar, and high on the left bank where active erosion (possibly due to mining) was observed. Upland habitat at the transect consisted of recently burned scrub/shrub. The water was clear and turbidity was low. Recreation was observed at the transect and a small fire ring was located approximately 2 m inland from the right edge of the transect. While there is only one set of habitat transect data for this site, a qualitative assessment showed no discernible evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat. 4.0 Results 4-44 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 .tn & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure 4-32. Habitat assessment transect (red line) at Site WBFR-2, looking toward river left, September 25, 2025. 4.0 Results 4-45 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 l i n g Butte Creek Foothill Yellow-legged Frog Monitoring 2025 5.0 Discussion 5.1 2025 Survey Results Biologists observed FYLF at all Butte Creek sites surveyed during the 2025 VESs. The survey effort included eight representative sites along Butte Creek located downstream of the area affected by the Butte Canal breach and resulting sediment plume in 2023. Evidence of successful FYLF breeding to metamorphosis was documented at six of the eight sites, where both tadpoles and YOY were observed. At the remaining two sites, no egg masses or tadpoles were detected; a single subadult was observed at Site BC-1, and YOY, subadults, and adults were observed at Site BC-3. Site BC-1 was generally characterized as poor-quality FYLF habitat, and no egg masses or tadpoles have ever been documented at that site during any past surveys. In 2006, biologists observed YOY in the BC-1 survey reach; however, those post-metamorphic frogs could have originated from nearby sites with moderate- to high-quality habitat where breeding has been consistently observed (e.g., Site BC-2). Similarly, although only YOY provided the only possible evidence of breeding at Site BC-3 in 2025, both tadpoles and YOY were observed there in 2006 and 2024 (PG&E 2008, 2025a). It is unclear whether eggs and/or tadpoles were simply undetected during the 2025 survey effort or if YOY migrated from more productive areas (e.g., Site BC-2). Breeding was also observed in 2025 at both WBFR sites (WBFR-1 and WBFR-2), which were included to compare FYLF breeding and recruitment in reaches not affected by the breach. Numerous individuals of all life stages were observed at both sites. FYLF breeding and oviposition in Butte Creek and the WBFR occurred in late May to early June, consistent with known breeding phenology in California (Hayes et al. 2016). In 2025, biologists first observed egg masses at Sites BC-6, BC-7, BC-12, and WBFR-2 during surveys on May 20- 22. While not surveyed in early May due to access limitations, hatched egg masses and tadpoles were observed at Site BC-7 on May 20, in a series of warm backwater pools with varying degrees of connectivity to the main channel (mostly disconnected or partially connected). Because survey timing is dictated by flow conditions, surveys may be delayed in spring until biologists can safely access survey reaches. Considering this and for future analyses, inconsistent egg mass count data can either be incorporated into population-estimate modeling, or a different FYLF life stage (e.g., adult) can be used in the analysis, as described in the Study Plan (PG&E 2025b). Throughout the season, biologists documented one desiccated egg mass, five deceased tadpoles, and five deceased post-metamorphic frogs. This included three adult FYLF found dead with unknown causes of mortality (one at Site BC-12 and two at Site BC-7). Notably, one of the deceased adults was being consumed post-mortem by a northwestern pond turtle, and another was observed with an egg mass partially emerged from its cloaca. Surveys documented a single deceased YOY at each of the WBFR sites (WBFR-1 and WBFR-2), five dead tadpoles at Site WBFR-1, and one desiccated egg mass at Site WBFR-2. While the causes of mortality are unknown, there is no evidence linking FYLF deaths to project operations or management activities. If a single underlying factor were responsible, mortality would likely have been concentrated 5.0 Discussion 5-1 March 2026 O2026, Pacific Gas and Electric Company • Document Accession #: 20260309-0002 Filed Date: 03/09/2026 l i n . & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 within specific reaches or time periods. Instead, a few dead individuals were observed across both Butte Creek and WBFR sites and throughout the monitoring season. Overall, these mortalities represented less than 1 percent of all observations, consistent with mortality observations commonly reported in anuran surveys. 5.2 Spatial and Temporal Population Demographic Variability While statistical analysis and population size estimates were not conducted as part of this 2025 report, information on the abundance and distribution of FYLF by life stage was evaluated to look for spatial patterns and temporal trends that may inform early evaluation of significant loss, per the Study Plan (PG&E 2025b). Interannual variability and site comparisons were evaluated using individual count data 2; Appendix D provides a table summarizing FYLF count data across monitoring years used to inform this evaluation. Future analysis would model imperfect detection and estimated population size to more thoroughly assess potential impacts of the Butte Canal breach and differences observed across sites and survey years. Overall, more FYLF of most life stages 3 were observed in Butte Creek in 2025 compared with 2024, and in Butte Creek and the WBFR in 2025 compared with the baseline relicensing data from 2006. There was variability among survey years when looking at individual sites. For example, in 2025, the tadpole count data were orders of magnitude higher at Sites BC-7, BC-8, and BC-12 while considerably lower at Sites BC-4 and BC-6 compared with 2024. The abundance of a given life stage shifted among sites between survey years. In 2006, biologists observed substantially higher numbers of most life stages of FYLF at Site BC-6 compared with Site BC-7, with 47 egg masses observed at Site BC-6 and no egg masses observed at Site BC-7. However, that trend was reversed in 2025, and only one egg mass was observed at Site BC-6 and 69 egg masses (42 hatched and 27 active) were observed at Site BC-7. Similar shifts in the FYLF population distribution can be seen at WBFR sites. For example, in 2006, biologists observed 20 adults at Site WBFR-1 compared with 7 adults at Site WBFR-2. In 2O25, over 6O adults were observed at Site WBFR-2 compared with only 4 adults in Site WBFR-1. These patterns likely reflect natural population movements among reaches and/or habitat changes over the 19-year survey history. In general, across Butte Creek and the WBFR, there were no obvious or substantial changes in FYLF population size or demographics from 2006 to 2025 that would suggest declining or diminishing FYLF populations. Biologists observed more FYLF post-metamorphic frogs at WBFR sites compared with the Butte Creek sites. The WBFR sites had a higher number of observed YOY, subadult, and adult FYLF compared with Butte Creek sites in 2025, and a higher number of subadult and a similar number 2 Count data were summarized by the total number of FYLF observed grouped by life stage at each site during each survey effort; an exception was made for egg masses, for which exact total counts were available and used. The highest number of FYLF observed at each site during a single survey event for each year was used for spatial and temporal comparisons to account for varying number of field surveys conducted over the years. 3 There were more YOY and similar number of subadults observed in Butte Creek in 2006 compared with 2025, and a similar number of egg masses observed in WBFR in 2006 compared with 2025. 5.0 Discussion 5-2 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 91g . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 of adult FYLF compared with Butte Creek Sites in 2006. However, that pattern is not seen across all life stages. BC-7 and BC-6 on Butte Creek had the highest egg mass and tadpole counts of all sites, including at the WBFR sites in 2025 and 2006, respectively. The difference in the number of post-metamorphic FYLF observations between the two rivers may be a result of differences in habitat complexity, as higher FYLF population densities have been associated with stream reaches having greater geomorphic habitat heterogeneity (Yarnell 2005). The differences in FYLF observed between the WBFR and Butte Creek could be attributed to the distribution and abundance of bullfrogs, a non-native predator of FYLF. While there are no known documented bullfrog sightings on the WBFR during previous relicensing or monitoring surveys, bullfrogs are present and appear to have moved up the Butte Creek drainage since 2006. During the 2006 relicensing surveys, bullfrogs were only documented at sites BC-1 through BC-3, whereas during the 2024 and 2025 surveys, evidence of bullfrog breeding was found up to Site BC-6. In 2024, a bullfrog adult was seen even farther upstream at prior Site BC-9, located near Lower Centerville Diversion Dam, though that site was removed from the monitoring program after one visit due to safety concerns, and not surveyed in 2025. Bullfrogs have been reported as a conservation concern for declining anuran species (Bury and Whelan 1984, Moyle 1973). They are also a known reservoir for Batrachochytrium dendrobatidis, the pathogen that causes chytridiomycosis, which has been documented to cause die-offs in FYLF populations (Adams et al. 2017). Bullfrog tadpoles may also impact grazing by FYLF tadpoles, resulting in poorer body conditions at metamorphosis (Kupferberg 1997). Appendix E provides a table with bullfrog count data across monitoring years. Available data from 2023-2025 do not indicate that population-level demographic and abundance changes on Butte Creek since 2006 are a result of the Butte Canal breach. The breach occurred in August 2023, and the pulse flow of sediment would likely have had the largest effect on FYLF tadpoles because they are fully aquatic with limited ability to move locations and seek refuge. If the breach had resulted in a near-total FYLF tadpole cohort failure in 2023, few subadults would have been expected in 2024, followed by a reduced number of adults observed in 2025, and subsequently reduced breeding and recruitment in 2026. However, biologists observed more adult FYLF at Butte Creek sites in 2025 compared with 2024 and 2006, and a similar or substantially higher number of subadult FYLF at Butte Creek sites in 2025 compared with 2006 and 2024, respectively, suggesting no currently discernible impacts from the canal breach on the population based on the data available. The August 2023 breach likely resulted in localized mortality of a portion of the FYLF tadpole cohort through mechanisms such as smothering by fine sediment, reduction of interstitial refuge, and temporary loss of existing algal food resources. These impacts were likely spatially variable, with greater effects in habitats that experienced deeper or more persistent sediment deposition. At the same time, partial survival of tadpoles is likely because of the spatial heterogeneity of tadpole rearing habitats, including the use of shallow edgewaters, backwater pools, and low-velocity side channels (Kupferberg 1996). During the 2023 sediment pulse, such habitats may have functioned as refugia, allowing a portion of the larval cohort to avoid lethal burial or starvation despite sediment deposition in other parts of the channel. Although fine sediment likely buried some cobble substrates, studies indicate that periphytic biofilms can persist and remain metabolically active on fine sediments and in low-velocity depositional habitats, and that grazing organisms can 5.0 Discussion 5-3 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 F8 i , Butte Creek Foothill Yellow-legged Frog Monitoring 2025 continue to exploit these food resources where cobble-associated algae are reduced (Kupferberg 1997, Biggs et al. 1999, Perez-Calpe et al. 2021). The observation of YOY FYLF in September and October 2023 following the canal breach (PG&E and Stillwater Sciences 2023), presence of subadults in 2024, and observed successful breeding and recruitment in 2025 further support the inference that the disturbance likely resulted in only a partial loss of the 2023 tadpole cohort. Because FYLF typically require two to three years to reach reproductive maturity, population- level responses to disturbance may be delayed relative to the year of impact (Kupferberg et al. 2009). As described in the FERC-approved Study Plan and in accordance with agency requirements, FYLF monitoring in Butte Creek will continue annually through 2028. This continued monitoring, including comparison with control sites and historical data, will be useful for detecting any delayed effects and informing whether adaptive management strategies are needed. 5.0 Discussion 5-4 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 l iffl . & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 6.0 References Adams, A.J., S.J. Kupferberg, M.Q. Wilber, A.P. Pessier, M. Grefsrud, S. Bobzien, V.T. Vredenburg, and C.J. Briggs. 2017. Extreme drought, host density, sex, and bullfrogs influence fungal pathogen infection in a declining lotic amphibian. Ecosphere 8: e01740. 10.1002/ecs2.1740. Biggs, B.J.F., Smith, R.A., and Duncan, M.J. 1999. Velocity and sediment disturbance of periphyton in headwater streams: Biomass and metabolism. Journal of the North American Benthological Society 18: 222-241. Brown, L.R., and P.B. Moyle, 1997. Invading species in the Eel River, California: successes, failures, and relationships with resident species. Environmental Biology of Fishes 49: 271- 291. Bury, R.B. 1986. Feeding ecology of the turtle, Clemmys marmorata. Journal of Herpetology 20: 515-521. Bury, R.B., and J.A. Whelan. 1984. Ecology and management of the bullfrog. U.S. Fish and Wildlife Service Resource Publication 155: 1-23. Catena77i, A. and S.J. Kupferberg. 2017. Variation in thermal niche of a declining river-breeding frog: From counter-gradient responses to population distribution patterns. Freshwater Biology. 62: 1,255-1,265. GANDA. 2020. Foothill yellow-legged frog monitoring at Little Carson Creek and Big Carson Creek, Mt. Tamalpais Watershed, 2018 to 2019. Available at: https://marinwater.org/wp- content/uploads/2023/09/Foothill-Yellow-legged-Frog-2018-19.pdf Gosner, K.L. 1960. A simplified table for staging anuran embryos and larvae with notes on identification. Herpetologica 16: 183-190. Hayes, M.P., C.A. Wheeler, A.J. Lind, G.A. Green, and D.C. Macfarlane. 2016. Foothill yellow- legged frog conservation assessment in California. General Technical Report PSW-GTR- 248. Albany, CA: US Department of Agriculture, Forest Service, Pacific Southwest Research Station. Hays, D.W., K.R. McAllister, S.A. Richardson, and D.W. Stinson. 1999. Washington State recovery plan for the western pond turtle. Washington Department of Fish and Wildlife, Olympia, WA. Holland, D.C. 1985. An ecological and quantitative study of the western pond turtle (Clemmys marmorata) in San Luis Obispo County, California. Master's thesis. California State University, Fresno. 6.0 References 6-1 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 rg . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Kupferberg, S.J. 1996. Hydrologic and geomorphic factors affecting conservation of a river-breeding frog (Rana boylii). Ecological Applications 6: 1332-1344. Kupferberg, S. 1997. The role of larval diet in anuran metamorphosis. American Zoologist 37: 146-159. Kupferberg, S. J., Lind, A.J., and Palen, W. J. 2009. Pulsed flow effects on the foothill yellow- legged frog (Rana boylii): Population modeling. California Energy Commission, Public Interest Energy Research Program. CEC-500-2009-021. Kupferberg, S., A. Catenaz7i, M. Power. 2011. The importance of water temperature and algal assemblage for frog conservation in northern California rivers with hydroelectric projects. California Energy Commission. University of California, Berkeley. Publication Number: CEC-500-2014-033 Moyle, P.B. 1973. Effects of introduced bullfrogs, Rana catesbeiana, on the native frogs of the San Joaquin Valley, California. Copeia 1973: 18. DOI: https://doi.org/10.2307/1442351. Perez-Calpe, A.V., Larratiaga, A., von Schiller, D., and Elosegi, A. 2021. Interactive effects of discharge reduction and fine sediments on stream biofilm metabolism. PG&E (Pacific Gas & Electric Company). 2003. Results of 2003 surveys and monitoring for foothill yellow-legged frog (Rana boylii) within the Rock Creek-Cresta Project Area, North Fork Feather River, Recreation and Pulse Flow Biological Evaluation. Report prepared by GANDA for Pacific Gas and Electric Company. PG&E. 2008. DeSabla-Centerville Project (FERC Project No. 803-068), updated study results and license application sections—Updated Section 6.3.2.1: Assessment of RT&E amphibian and aquatic reptile species habitat near project reservoirs and project-affected stream reaches (Study 6.3.3-3), and Updated Section 7.3.2, Pacific Gas and Electric Company, San Francisco, CA. PG&E. 2025a. Butte Creek foothill yellow-legged frog monitoring 2024. January 2025. Oakland. CA. Prepared by Stillwater Sciences, Berkeley, CA. PG&E. 2025b. Foothill yellow-legged frog study plan: Butte Creek 2025-2028. May 2025. Prepared by Pacific Gas and Electric Company, Oakland, CA, and Stillwater Sciences, Berkeley, CA. PG&E and Stillwater Sciences. 2023. Butte Creek canal breach—foothill yellow-legged frog study results, 2023. Technical Memorandum from PG&E to Central Valley Regional Quality Control Board and California Department of Fish and Wildlife. Seltenrich, C.P., and A.C. Pool. 2002. A standardized approach for habitat assessments and visual encounter surveys for the foothill yellow-legged frog (Rana boylii). Pacific Gas and Electric Company, San Francisco, CA. 6.0 References 6-2 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 !In i & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Vredenburg, V.T. 2004. Reversing introduced species effects: experimental removal of introduced fish leads to rapid recovery of a declining frog. Proceedings of the National Academy of Sciences 101: 7,646-7,650. Wheeler, C.A., J.B. Bettaso, D. T. Ashton, and H.H. Welsh, Jr. 2014. Effects of water temperature on breeding phenology, growth, and metamorphosis of foothill yellow-legged frogs (Rana boylii): a case study of the regulated mainstem and unregulated tributaries of California's Trinity River. River Research and Applications 31: 1,276-1,286 Yarnell, S.M. 2005. Spatial heterogeneity of Rana boylii habitat: physical processes, quantification and ecological meaningfulness. Doctoral dissertation, University of California, Davis. Zweifel, R.G. 1955. Ecology, distribution, and systematics of frogs of the Rana boylii group. University of California Publications in Zoology 54: 207-292. 6.0 References 6-3 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 r& . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 APPENDIX A FLOW AND WATER TEMPERATURE DATA Appendix A March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 This Page Intentionally Left Blank Appendix A March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 F 1I t Tir; to 0 800 700 100 10/1/2: 0.0 4/1/25 5/1/25 6/1/25 7/1/25 Date —WaterTemperature, Centerville Powerhouse — Water Temperature, Lower Centerville Diversion Dam —— Flow, BW97 - Butte Creek below Butte Creek Diversion Dam --- Flow, BW98 - Butte Creek belowCenterville Diversion Dam Estimated Oviposition Period at Butte Creek Sites (April 29 to June17) 600 25.0 ; c.) _ • • • 15.0 43 500 0 LL 400 >. 1.13 03 300 200 8/1/25 9/1/25 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 PGIE Butte Creek-2025 Figure A-1. Flow and water temperature data at locations along Butte Creek, 2025 Appendix A A-1 ©2026, Pacific Gas and Electric Company March 2026 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 18 - 1400 7,1,5 Date B/1/25 9/1/_5 —Water Temperature, Hendricks Head Dam --- Flow, WBFR at Miocene Diversion Dam (CA Department of Water Resources gage WFR) 16 1200 1000 Estimated Oviposition Period at WBFR Sites (May 8 to June 16) 775 cu O. 10 800 600 iu f - ................... 400 200 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 West Branch Feather River (WBFR) - 2025 Figure A-2. Flow and water temperature data at locations along the West Branch Feather River, 2025 Appendix A A-2 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Yankee Hill o 70 FOOTHILL YELLOW-LEGGED FROG STUDY - BUTTE CREEK • t BC- I 2 Forks of Butte til Camping Area Doe Mill Rd Bridge Forest Ranch Lower Centerville ur Bw98 . Diversion Dam Paradise Cr Lake 45' 3 2 •Z" BC-8 ANL " ck BC-7 49 ,.., cci-. ':i'l' BC-6 0 „,:' Centerville Powerhouse Cr eek Centerville Rd Bridge A C BC-4J .<4 WBFR-2 Magalia Reservoir AWBFR-1 Magalia° WFR Cr. Paradise 141 m& . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Map Sources. Roads, rivers, cities, waterbodies: ESR1 2016 USGS tornetetc v.rI 2NXe5 StinlVaterSCiellre, FYLF Monitoring Area / 2025 survey site Lake/reservoir A Landmark Perennial stream 0 Flow gage Intermittent stream Temperature monitoring station Infrastructure PIS I • Butte Canal Sediment Input Area 0 0,5 I Figure A-3. Butte Creek and West Branch Feather River foothill yellow-legged frog monitoring area, including temperature and flow measurement locations, 2025. Appendix A A-3 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Fji Butte Creek Foothill Yellow-legged Frog Monitoring 2025 APPENDIX B NON-TARGET SPECIES OBSERVATIONS Appendix B March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 This Page Intentionally Left Blank Appendix B March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure B-1. Sierra newt (Taricha sierrae) egg mass (top left), larva (top right), young-of year (bottom left), and adult (bottom right). Appendix B B-1 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 11,3 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure B-2. Sierra newt adult predation on foothill yellow-legged frog (Rana boylii) egg mass at Site WBFR-1. Figure B-3. California toad (Anaxyrus boreas halophis) egg mass (top left), tadpoles (top right), young-of-year (bottom left), and adult (bottom right). Appendix B B-2 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 trj Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure B-4. Sierran treefrog (Pseudacris sierra) tadpoles (top left), young-of-year (top right), subadult (bottom left), and adult (bottom right). Appendix B B-3 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 1173 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure B-5. American bullfrog (Lithobates catesbeianus) first-year tadpole (top left), second-year tadpole (top right), subadult (bottom left), and adult (bottom right). Appendix B B-4 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 E Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure B-6. Northwestern pond turtle (Actinemys marmorata) young-of-year (top left and top right), subadult (bottom left), and adult (bottom right). Appendix B B-5 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure B-7. Sierra garter snake (Thamnophis couchii) subadult (left) and adult eating a riffle sculpin (Cottus gulosus) (right). Figure B-8. Valley garter snake (Thamnophis sirtalis fitcht) subadults. Appendix B B-6 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 .tn & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 APPENDIX C PHOTOGRAPHS OF SURVEY SITES Appendix C March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 This Page Intentionally Left Blank Appendix C March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 trI Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-1. Site BC-1, various locations and survey conditions on May 7 (top left) and September 24 (top right and bottom), 2025. Appendix C C-1 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Appendix C March 2026 C-2 ©2026, Pacific Gas and Electric Company tr3 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-2. Rock weirs at Site BC-1 on May 21 (left) and June 4 (right), 2025. Figure C-3. Deep inaccessible mid-channel pool at Site BC-1 on May 7, 2025. Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-4. Site BC-2, various locations and survey conditions on May 6 (top) and September 24 (bottom), 2025. Appendix C C-3 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Ilrbla Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-5. Large gravel bar with high concentration of foothill yellow-legged frogs (Rana boylii) at upstream extent of Site BC-2 on May 6 (left) and September 24 (right), 2025. Figure C-6. Side channel at Site BC-2 on May 19 (left) and September 24 (right), 2025. Appendix C C-4 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 !I! Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-7. Site BC-3, various locations and survey conditions on June 5 (top left) and September 24 (top right and bottom), 2025. Appendix C C-5 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Appendix C C-6 ©2026, Pacific Gas and Electric Company March 2026 Figure C-8. Site BC-4, various locations and survey conditions on May 19 (top left), June 19 (top right), and August 18 (bottom), 2025. Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-9. Extensive cobble bar and associated side channel and backwater complex at Site BC-4 on May 5 (left) and June 19 (right), 2025. Figure C-10. Deep mid-channel pool upstream of cobble bar at Site BC-4 on August 28, 2025. Appendix C C-7 A4arch 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-11. Site BC-6, various locations and survey conditions on May 7 (top left), May 21 (top right), and June 18 (bottom) 2025. Appendix C C-8 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-12. The two backwater pools at Site BC-6 on June 4 (left) and June 18 (right), 2025. Figure C-13. Deep mid-channel pool at Site BC-6 an June 18, 2025. Appendix C C-9 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-14. Site BC-7, various locations and survey conditions on May 20 (top left), June 18 (top right), and September 24 (bottom) 2025. Appendix C C-10 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 3 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-15. Backwater bedrock pools with high concentrations of foothill yellow-legged frog egg masses and tadpoles at Site BC-7 on May 20 (left) and September 24 (right), 2025. Figure C-16. Deep mid-channel pool at Site BC-7 on September 24, 2025. Appendix C C- 1 1 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-17. Site BC-8, various locations and survey conditions on June 3 (top left), June 17 (top right), and September 24 (bottom), 2025. Appendix C C-12 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Figure C-18. Side channel habitats at Site BC-8 on September 23, 2025. Figure C-19. Bedrock pool at Site BC-8 on June 3, 2025. ra Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Appendix C C-13 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Figure C-20. Site BC-12, various locations and survey conditions on May 20 (top left), August 26 (top right), and September 24 (bottom), 2025. Document Accession #: 20260309-0002 Filed Date: 03/09/2026 tfl Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Appendix C C-15 March 2026 Figure C-21. Deep run at Site BC-12 on June 3, 2025. Figure C-22. Bedrock backwater pool at Site BC-12 on June 17, 2025. ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-23. Site WBFR-1, various locations and survey conditions May 22 (top left), June 16 (top right), and September 26 (bottom) 2025. Appendix C C-16 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 m Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-26. Site WBFR-2, various locations and survey conditions May 22 (top left), June 16 (top right), and September 25 (bottom), 2025. Appendix C C-18 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 !IP Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Figure C-27. Overhanging and emergent vegetation at Site WBFR-2 on September 25, 2025. Figure C-28. Large cobble bar with high concentrations of foothill yellow-legged frog egg masses at Site WBFR-2 on June 2, 2025. Appendix C C-19 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Ir, , Butte Creek Foothill Yellow-legged Frog Monitoring 2025 APPENDIX D FOOTHILL YELLOW-LEGGED FROG COUNT DATA ACROSS SURVEY YEARS Appendix D March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 .tn , Butte Creek Foothill Yellow-legged Frog Monitoring 2025 This Page Intentionally Left Blank Appendix D March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Fl& . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Table D-1. The highesta number of foothill yellow-legged frogs (Rana boylii) observed at each site during a single survey event for each monitoring year, by life stage. Site Life Stage Year 2006' 2023e 2024d 2025e BC-1 Egg mass 0 NS NS 0 Tadpole 0 NS NS 0 YOY 22 NS NS 0 Subadult 5 NS NS 1 Adult 0 NS NS 0 BC-2 Egg mass 0 NS NS 0 Tadpole 0 NS NS -650 YOY 5 NS NS 44 Subadult 10 NS NS 6 Adult 1 NS NS 3 BC-3 Egg mass 0 NS 0 0 Tadpole 2 NS -50 0 YOY 20 NS 1 8 Subadult 0 NS 1 10 Adult 0 NS 0 2 BC-4 Egg mass 0 0 0 0 Tadpole 785 0 -250 -100 YOY 19 9 15 --109 Subadult 0 0 0 2 Adult 1 1 1 2 BC-6 Egg mass 47 0 0 1 Tadpole 2340 0 -105 10 YOY 401 0 25 9 Subadult 3 0 0 0 Adult 3 0 1 3 Appendix D D-1 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 RI& , Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Site Life Stage Year 2006' 2023' 202O 2025' BC-7 Egg mass 0 NS 0 69 f Tadpole 473 NS -157 -15,720 YOY 229 NS 17 17 Subadult 2 NS 1 4 Adult 1 NS 4 14 BC-8 Egg mass 0 NS 0 23f Tadpole 716 NS —430 -4,795 YOY 341 NS 46 —114 Subadult 6 NS 0 3 Adult 8 NS 3 4 BC-12 Egg mass 8 0 0 10 Tadpole 207 1 -200 -2,235 YOY 5 0 20 17 Subadult 3 0 0 2 Adult 11 2 0 7 NA, B FR-1 Egg mass 15 NS NS 8 Tadpole 127 NS NS -600 YOY 326 NS NS —559 Subadult 12 NS NS 10 Adult 20 NS NS 4 WBFR-2 Egg mass 34 NS NS 39 Tadpole 94 NS NS —2,425 YOY 90 NS NS 677 Subadult 7 NS NS 29 Adult 7 NS NS 66 Notes: — = approximately; NS = Not surveyed; YOY = young-of-year a The highest number of foothill yellow-legged frogs observed at each site during a single survey event for each year was used for annual comparisons to account for varying numbers of field surveys across survey years. b In 2006, three surveys were conducted: one in June, one in July, and one in September. In 2023, two surveys were conducted: one in September and one in October. These data were not used for comparisons because the effort was constrained to two visits targeting YOY as compared with full season surveys in 2006, 2024, and 2025. d In 2024, three to four surveys were conducted: one or two in June (based on safe access early in the month), one in August, and one in September. Appendix D D-2 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 r& . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 In 2025, six surveys were conducted: one or two in June (based on safe access early in the month), one in August, and one in September. f Recently hatched egg masses are included in this egg mass count because they indicate known egg masses laid prior to the first survey. Appendix D D-3 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 tin & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 APPENDIX E AMERICAN BULLFROG COUNT DATA ACROSS SURVEY YEARS Appendix E March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 tin & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 This Page Intentionally Left Blank Appendix E March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 t ir! & Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Table E-1. The highesta number of American bullfrogs (Lithobates catesbeianus) observed at each site during a single survey event for each monitoring year, by life stage. Site Life Stage Yea rb 2006' 2024d 2025' BC-1 Egg mass 0 NS 0 Tadpole 25 NS -668 Adult/Subadult 4 NS 11 BC-2 Egg mass 0 NS 0 Tadpole 10 NS -220 Adult/Subadult 0 NS 6 BC-3 Egg mass 0 0 0 Tadpole 500 -151 -2,000 Adult/Subadult 1 1 5 BC-4 Egg mass 0 1 0 Tadpole 0 --200 -320 Adult/Subadult 0 0 1 BC-6 Egg mass 0 0 0 Tadpole 0 -300 -1,000 Adult/Subadult 0 2 3 BC-7 Egg mass 0 0 0 Tadpole 0 0 0 Adult/Subadult 0 0 0 BC-8 Egg mass 0 0 0 Tadpole 0 0 0 Adult/Subadult 0 0 0 BC-90. Egg Mass 0 0 NS Tadpole 0 0 NS Adult/ Subadult 0 1 NS BC-12 Egg mass 0 0 0 Tadpole 0 0 0 Adult/Subadult 0 0 0 Appendix E E-1 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 r8 . Butte Creek Foothill Yellow-legged Frog Monitoring 2025 Site Life Stage Year" 2006e 2024d 2025e WBFR-1 Egg mass 0 NS 0 Tadpole 0 NS 0 Adult/Subadult 0 NS 0 WBFR-2 Egg mass 0 NS 0 Tadpole 0 NS 0 Adult/Subadult 0 NS 0 Notes: — = approximately; NS = Not surveyed a The highest number of bullfrogs observed at each site during a single survey event for each year was used for annual comparisons to account for varying numbers of field surveys across survey years. b Data for 2023 were not included because the effort was constrained (in sites, time, and site lengths) compared with 2006, 2024, and 2025; three sites (BC-4, BC-6, and BC-12) were surveyed twice in fall (once in September and once in October). No bullfrogs were recorded. In 2006, three surveys were conducted: one in June, one in July, and one in September. d In 2024, three to four surveys were conducted: one or two in June (based on safe access early in the month), one in August, and one in September. e In 2025, six surveys were conducted: one or two in June (based on safe access early in the month), one in August, and one in September. r Site BC-9 was removed from the monitoring program after one visit in 2024 due to safety concerns. Appendix E E-2 March 2026 ©2026, Pacific Gas and Electric Company Document Accession #: 20260309-0002 Filed Date: 03/09/2026 ENCLOSURE 2 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Section Page No. Commenter Conthent/Suggested Edits Related Sentence(Topic Of applicable) Response Report updated? Executive Summary v USFWS Please define or quantify 'robust' here Key findings indicate that a robust FYLF population persists in Butte Creek, with all life stages—egg masses, tadpoles, young-otiyear (YOY), subadults, and adults--observed at most sites. Comment addressed by adding text to define a "robust" FYLF population. supporting Wilde stages as well as breeding and recruitment across most sites with a substantial number of egg masses observed. Yes Executive Summery v USFWS We suggest altering language to avoid making conclusions about impacts due to the overall lack of data at this point in time Overall, the preliminary study results do not suggest a declining or unstable FYLF population in Butte Creek. with no current mdiution of long-tenn population-level impacts attributable to the 2023 canal bleach Comment noted, with clarifying edits to the report text. The August 15, 2025 FERC Order approving the FYLF Monitoring Plan requires annual evaluation of monitoring results to assess whether a significant loss has occurred or is ocmaring dunng the respective year. Consistent weh that directive, this report presents interim. data-hmaed interpretations based on available informatton. Wade explicitly acknoidedging uncertainty and the need for corihnued monitoring. Final determinations regarding long-term impacts and mitigation will be made at the conclusion of the study period, as directed by FERC. Yes 1.0 Background 1.1 USFWS This is incomplete. Recommend Incorporating information about FERC order to develop and implement the mongering plan along with what F ERG ordered should be in each annual report. In 2025, PG&E further expanded the FYLF study—per the Foothill Yelkwwlegged Frog Study Plan Butte Creek 2025-2028 (PG&E 2025b)—to better assess the population and degree of potential effects of the Butte Canal breach on FYLF in 80110 Creek. Comment addressed by adding information about the FERC order to develop and implement the mninitnnng plan along with what FERC ordered should be in each annual report. Y. 4.0 Results 4.-24 USFWS In the discussion, there's a comparison of bullfrogs observed over time and potential impacts to FYLF population. It might be informative to create a summary table of total American bullfrog observations by site and year that gets added onto each year the monttonng is conducted. Table 4.6. Number of Arnencan bullfrogs observed by tile stage during surveys on Butte Creek and the West Branch Feather River, 2025 Comment addressed by providing a new table summarizing the highest number of American bullfrogs observed at each site during a single survey event for each monitoring year, by life stage (Appendix E. reference added to the Discussion section). Highest counts were used instead of total counts to account for differences in numbers of survey visits and timing over the years. Yes, Appendix E 42 Fiabilat Assessments and Tramects 4-31 USFWS For habitat assessment, did surveyors record presence of red fine sedthent that is sander to what was released during the canal failure? If so. for each Bale Creek site, it would be helpful to provide information about the presence of that sediment Habitat Asses...rola and Trensecla Comment addressed by adding text noting that surveyors did not observe any red fine sediment pe., similar to what was released during the canal failure) at any site during 2025 (or 2024) surveys. Yes 4.2 Habitat Assessments and Transects 4-31 USFWS Is this just companng data from the last 2 years? Data collected from established habitat transacts showed no evidence of vegetation encroachment that would impact the suitability of FYLF breeding habitat . This assessment of vegetation encroachment potentially impacting the suitability of FYLF breeding habitat is from comparing habitat transact data collected from the last two monitoring years. as well as qualitative assessments for sites with only one set of habitat transact data. In addition, we also made qualitative comparisons with 2023 data and photos for BC-4, BC-6, and BC-12, and conducted a coarse/qualitative evaluation of 2006 habitat photos as feasible. Not applicable 4.2.1 through 4.210 (abates) 4.31 through 4-45 USFWS Recommend adding a sentence identifying if vegetation encroachment is impacting the suitability of that site for breadfing (Commend added to ad sites) Comment addressed by adding a sentence to each site identifying if vegetation encroachment is discernably impacting the suitability of that site for breeding. Yes 4.2.6 Site BC-7 4-39 USFWS Was this mining claman ming camp present in 2006? An active mining clean and mining camp are associated with the survey wt.. related impacts include channel manipulation, increased erosion, and anthropogenic debris within the channel. There is no sign or mention of a mining ramp or claim in the 2006 report and related habitat photos. Also, based on a review of the claim number on the BLM Mineral 8 Land Records System, it appears a claim in this area was filed in September 2022 (Serial Number CA105787318). Not applicabk 42.10 Site WBFR-2 4-45 USFWS Recommend adding sentence about habitat quality, similar to what was done for all other site descriptions. 4.210 Site WBFR-2 Comment addressed by adding a sentence about habitat quality for Site WBFR-2. Yes 5.12025 Survey Results 5-1 USFWS Because of the potential for YOY to migrate between Sites, finding oNy YOY is not sufficient evidence of breeding here. Similarly although only YOY provided the only possible evidence of breading at Site BC-3 in 2025, both tadpoles and YOY were observed there in 2006 and 2024 (PG&E 2008. 2025a) It w unclear whether eggs ancttor tadpoles were simply undetected during the 2025 survey effort or if YOY migrated from more productive areas (e.g., Site BC-21. Comment addressed to clarify by adding The only possible. to the evidence of breeding at Site BC-3. The preceding and following sentences support the comment that YOY may have migrated from more productive areas, and do not confirm breeding. Also revised first paragraph to reduce the number of sites with emdence of successful breeding from seven to six. Yes 5.2 Spatial and Temporal Population Demographic Variability 5-2 USFWS Part of the FERC order states that they report should include a comparison of the results with 2006 survey data. While this draft report does give a high level written comparison, it could be greatly improved upon. Summary tablas (or figures) that include total egg masses, total tadpoles all visas, and total YOY, Amerika. and Adults observed by site and by year would enable readers to readily make comparisons and better follow the written discussion. The proposed table(s) would be added won for each year's report, such that next year the tables would have data from 2006, 2023 (very limited data), 2024, 2025, and 2026. 5.2 Spatial and Temporal Population Demographic Venabllity Comment addressed by providing a new table summarizing the highest number of FYLF observed at each site during a single survey event for each monitoring year. by rife stage (Appendix G reference added to the Discussion section), Highest counts were used Instead of total counts to account for differences in numbers of survey visits and firning over the years. Yes, Appendix D 5.2 Spatial and Temporal Population Demographic Variability 5-3 USFWS This is a general comment, not nece.anly meant to be addressed at this spot in the document. There are some sires at which anthropogenic admires might be Impacting FYLF. I understand it's totally outside the scope of this report. however, if these actMfies are occurnng on publicly ownedthanaged lands, perhaps there'd be some value in being able to pull together some of that information so that CDFW/FVVS could reach out and see if k's possible to reduce those direct impacts. NA Comment noted. Pnreery land ownership information by site: BC-1: GOAN, BC.-2: Mechoopda Indian Tribe of Chico Rancheria; BC-3: BLM; SC-4: FILM: BC-6: Private; BC-7- BLM; BC-8. PG&E; BC-12: ELM; WBFR-1, Lassen National Forest; WBFR-2: BLA4 and Private Not applicable lax Document Accession #: 20260309-0002 Filed Date: 03/09/2026 aloe creek Fr...Yellow ea,. Pea Marinette 2025 AAeric, Cnrnmen Section Page No. Commenter CommenUSuggested Edits Related SentencelTopic ill applicable) Response Report updated? E2 Spatial and Temporal Population Demographic Variability 5-3 USFWS This report has not prowded the corresponding data from 2023 and 2024 to have such a strong conclusion. Providing the recommended summary table of total observations at sites by year would be especially helpful. it the breach had sIgniticantly affected the FYLF tadpole population in 2023, few subadults would be expected in 2024, followed by a reduced number of adults observed in 2025, and subsequently reduced breeding end recruitment in 2026. Comment addressed by providing a new table summarizing corresponding data from prier monitoring years (Appendix D). des, including Appendix D 5.2 Spatial and Temporal Population Demographic Variability 5-3 USFWS While the discussion above provides excellent context to how impacts horn bullfrogs might be impacting FYLF, there's not a similar discussion about howAuhy tadpoles would've surround both the pulse flow of sediment AND sediment covering cobble and algae that remained in place in 2023 until at least the first high flow event, if the breach had sIgnificantly affected the FYLF tadpole population in 2023, few subadults would be expected in 2024, followed by a reduced number of adults observed in 2025, and subsequently reduced breeding and recruitment in 2026. Comment addressed by expanding the Discussion to acknowledge likely localized mortality of FYLF eggs and tadpoles following the 2023 sediment release and to explain how partial tadpole survival is likely despite sediment covering cobble and algae, based on habitat refugia, persistence of periphytic food resources, and the observation of young-of-year FYLF in fall 2023. Yes 5.2 Spatial and Temporal Population Demographic Variability 5-3 USFWS Providing the recommended summarytableifigure of total observations at sites by year would be especially helpful in backing up this statement. Currently numbers of observations are in different reports. Additianally, survey efforts from 2005 and 2025 were not identical (i.e.. different numbers of surveyvisits at different times of year). I suggest removing definitive language about impacts here. However. biologists observed more adult FYLF on Butte Creek sites in 2025 compared with 2024 and 2006. and a similar or substantially higher number of subadult FYLF on Butte Creek sites in 2025 compared voth 2006 and 2024 respectively, suggesting no currently discernable impacts from the canal breach on the population Comment (first half) addressed by providing a new table summarong corresponding data from. prior monitoring years (Appendix D). Comment (second halo noted. To account for varying number of survey visits aver the years, we used the highest number of FYLF observed at each site during a single survey event for each year for spatial and temporal comparisons. The August 15, 2025 FERC Order approving the FYLF Monitoring Plan requires annual evaluation of monitoring results to assess whether a significant loss has occurred or is occurring during the respective year. Consistent with that directive. this report presents intern, data-limited interpretations based on available information, while explicitly acknowledging uncertainty and the need for continued monitoring. Final determinations regarding long-term impacts and mitigation will be made at the conclusion of the study period, as directed by FE RC. Yes, including Appendix D 5.2 Spatial and Temporal Population Demographic Variability 5-3 USFWS Recommend including that the FERC order states that monitoring shall occur annually through 2028. Continued annual monitoring ',lauding companson with control sites and historical data, will be useful for detecting any delayed effects and informing whether adaptive management strategies are needed. Comment addressed by adding text acknowledging that FYLF monitoring in Butte Creek will continue annually through 2028 as described in the FERC-approved Study Plan and in accordance with agency requirements. Yes Document Accession #: 20260309-0002 Filed Date: 03/09/2026 ENCLOSURE 3 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 2/25/26, 11:05 AM Inbox - Drummond, Duncan - Outlook di Outlook RE: [EXTERNAL] FERC 803: Butte Creek FYLF Monitoring Report From Ramirez-Doble, Sky <S9RV@pge.com > Date Thu 2/19/2026 2:55 PM To Weinmann, Sophia@Wildlife <Sophia.Weinmann@Wildlife.ca.gov > Cc Herman, Andie <AEHb@pge.com >; Young, Megan <MRY2@pge.com >; Cheslak, Edward <EFC3@pge.com >; Reaves, Brittany L <brittany_reaves@fws.gov >; Walther, Janet <JMW3@pge.com >; Joseph, Matthew <MWJA@pge.com >; Holly Burger <burger@stillwatersci.com >; Call, Leslie@Wildlife <Leslie.Call@Wildlife.ca.gov >; Allison, Anna@Wildlife <Anna.Allison@wildlife.ca.gov >; Millsap, Stephanie D <stephanie_millsap@fws.gov >; Puccini, Stephen@Wildlife <Stephen.Puccini@wildlife.ca.gov >; Drummond, Duncan <DGDH@pge.com > Hi Sophia, Thank you for the request. At this time, PG&E is unable to extend the agency comment deadline to February 27, 2026. To meet the March 1, 2026, filing deadline established in FERC's August 15, 2025, Order, PG&E requests that any agency comments on the 2025 Butte Creek FYLF Monitoring Report be provided by Wednesday, February 25, 2026, for inclusion in the FERC filing. Any comments submitted the week of February 23, 2026, will not be incorporated into the report; however, comments before February 25, 2026, will be included in the consultation record submitted to FERC. Thank you for your understanding, and please let me know if you have any questions. Kindly, Sky Ramirez-Doble He/Him/His Hydro License Coordinator I Power Generation Pacific Gas & Electric Company c: (530) 250-7002 e: s9rv@pge.com From: Weinmann, Sophia@Wildlife <Sophia.Weinmann@Wildlife.ca.gov> Sent: Thursday, February 19, 2026 11:54 AM To: Ramirez-Doble, Sky <S9RV@pge.com> Cc: Herman, Andie <AEHb@pge.com>; Young, Megan <MRY2@pge.com>; Cheslak, Edward <EFC3@pge.com>; Reaves, Brittany L <brittany_reaves@fws.gov>; Walther, Janet <JMW3@pge.conn>; Joseph, Matthew <MWJA@pge.com>; Holly Burger <burger@stillwatersci.com>; Call, Leslie@Wildlife <Leslie.Call@Wildlife.ca.gov>; Allison, Anna@Wildlife <Anna.Allison@wildlife.ca.gov>; Millsap, Stephanie D <stephanie_millsap@fws.gov>; Puccini, Stephen@Wildlife <Stephen.Puccini@wildlife.ca.gov> Subject: RE: [EXTERNAL] FERC 803: Butte Creek FYLF Monitoring Report This email came from outside PG&E. Think before you click. Be extra wary of links, attachments, providing sensitive information, and QR Codes. If this email seems suspicious, use the REPORT PHISH BUTTON. Hi Sky- https://outlook.office.com/ma il/id/AAkALgAAAAAAHYQD Ea pmEc2byACqACQ/02FEWg0ArOGv%2FVov3UOJ ktS6GcZCWgAG52PYKwAA?nativeVersio... 1/3 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 2/25/26, 11:05 AM Inbox - Drummond, Duncan - Outlook CDFW would like to request a deadline extension on FYLF Monitoring Report comments until Friday, February 27. I apologize for the delay and appreciate your understanding. Please let us know if the extension is possible. Best- Sophia Sophia Weinmann (she/her/hers) Environmental Scientist Foothill Yellow-legged Frogs From: Reaves, Brittany L <brittany reaves@fws.gov> Sent: Thursday, February 19, 2026 9:14 AM To: Ramirez-Doble, Sky <S9RVPpge.com>; Weinmann, Sophia@Wildlife <Sophia.WeinmannPWildlife.ca.gov>; Allison, Anna@Wildlife <Anna.AllisonPwildlife.ca.gov>; Call, Leslie@Wildlife <Leslie.CalIPWildlife.ca.gov>; Millsap, Stephanie D <stephanie millsap_@fws.gov> Cc: Herman, Andie <AEHb__Ppge.com>; Young, Megan <MRY2f@pge.conn>; Cheslak, Edward <EFC3Ppge.com>; Walther, Janet <JMW3Ppge.com>; Joseph, Matthew <MWJA@pge.com>; Holly Burger <burger@c~stillwatersci.com> Subject: Re: [EXTERNAL] FERC 803: Butte Creek FYLF Monitoring Report WARNING: This message is from an external source. Verify the sender and exercise caution when clicking links or opening attachments. I've attached the Butte Creek FYLF 2025 Monitoring Report word document with the Service's comments to this email. Thank you and please let us know if you have any questions. Brittany Reaves Fish and Wildlife Biologist U.S. Fish and Wildlife Service (530) 365-7150 *********************** I am currently working: Monday — Thursday From: Ramirez-Doble, Sky <S9RV@ipge.com> Sent: Thursday, January 22, 2026 5:04 PM To: Alber, Leslie@Wildlife <Leslie.Alber@a~wildlife.ca.gov>; Weinmann, Sophia@Wildlife <Sophia.WeinmannPWildlife.ca.gov>; Reaves, Brittany L <brittany reaves@a~fws.gov>; Millsap, Stephanie D <stephanie millsap@a~fws.gov>; Allison, Anna@Wildlife <Anna.allison@Jwildlife.ca.gov> Cc: Herman, Andie <AEHb@1pge.com>; Young, Megan <MRY2@a~pge.com>; Cheslak, Edward https://outlook.office.com/mail/id/AAkALgAAAAAAHYODEapmEc2byACqAC%2FEWg0ArOGv°/02FVov3UOJktS6GcZCWgAG52PYKwAA?nativeVersio 2/3 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 2/25/26, 11:05 AM Inbox - Drummond, Duncan - Outlook <EFC3@ipge.com>; Walther, Janet <JMW3_Apge.com>; Joseph, Matthew <MWJA@ipge.com>; Holly Burger <burgerPstillwatersci.com> Subject: [EXTERNAL] FERC 803: Butte Creek FYLF Monitoring Report This email has been received from outside of DOI - Use caution before clicking on links, opening attachments, or responding. Hello Agencies, The Butte Creek FYLF Monitoring Report for the 2025 monitoring year is now available for agency review, consistent with Ordering Paragraph (B) of FERC's August 15, 2025, Order. Per the FERC order, the agency review period runs 30 days from today. Please respond to this email with any comments or questions. The final report will be filed with FERC by March 1, 2026. The file is too large for email distribution. It can be accessed at the link below: AgeLcy Share - Butte Creek FYLF If you experience any access issues, please contact our consultant, Holly Burger, Stillwater Sciences, who manages the SharePoint permissions. Kindly, Sky Ramirez-Doble He/Him/His Hydro License Coordinator I Power Generation Pacific Gas & Electric Company c: (530) 250-7002 e: s9rvPpge.com You can read about PG&E's data privacy practices at PGE.com/privacy. https://outlook.office.co m/ma il/id/AAkALgAAAAAAHYQ D Ea pm Ec2byACgAC°/02FEWg0ArOGv°/02FVov3UOJ ktS6 G cZCWgAG52PYKwAA?nativeVersio... 3/3 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 ENCLOSURE 4 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 3/4/26, 12:51 PM Inbox - Drummond, Duncan - Outlook di Outlook RE: [External] DeSabla Centerville (FERC No. 803) — FYLF Annual Report Filing Issue From Holly Frank <Holly.Frank@ferc.gov > Date Tue 3/3/2026 10:45 AM To Ramirez-Doble, Sky <S9RV@pge.conn>; Andrea Claros <Andrea.Claros@ferc.gov > Cc Drummond, Duncan <DGDH@pge.com >; Joseph, Matthew <MWJA@pge.com > This email came from outside PG&E. Think before you click. Be extra wary of links, attachments, providing sensitive information, and QR Codes. If this email seems suspicious, use the REPORT PHISH BUTTON. Thank you Sky, I'm sorry you've run into issues with uploading the report, thank you for letting us know that you did get some parts submitted and for trying alternatives to getting the last enclosure submitted. I did receive the link you emailed. For providing a hard copy, submissions sent via the U.S. Postal Service must be addressed to: Debbie-Anne A. Reese, Secretary Federal Energy Regulatory Commission 888 First Street NE, Room 1A Washington, DC 20426. Submissions sent via any other carrier must be addressed to: Debbie-Anne A. Reese, Secretary Federal Energy Regulatory Commission 12225 Wilkins Avenue Rockville, Maryland 20852 The first page of any filing should include docket number P-803. Thank you! Holly Holly Frank Fish Biologist, FERC DHAC (202) 502-6833 From: Ramirez-Doble, Sky <S9RV@pge.com> Sent: Tuesday, March 3, 2026 1:25 PM To: Andrea Claros <Andrea.Claros@ferc.gov>; Holly Frank <Holly.Frank@ferc.gov> Cc: Drummond, Duncan <DGDH@pge.com>; Joseph, Matthew <MWJA@pge.com> Subject: RE: [External] DeSabla Centerville (FERC No. 803) — FYLF Annual Report Filing Issue Dear Ms. Claros and Ms. Frank, https://outlook.office.com/mail/inbox/id/AAkALgAAAAAAHYDDEapmEc2byACqAC%2FEWg0ArOGv%2FVov3UOJktS6GcZCWgAHNeC04AAA?native...1/3 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 3/4/26, 12:51 PM Inbox - Drummond, Duncan - Outlook Thanks for your quick communication on this matter. I wanted to follow up in writing to summarize next steps regarding the Annual Foothill Yellow-Legged Frog (FYLF) Monitoring Report filing for the DeSabla-Centerville Project (FERC No. 803). As discussed during my call with Ms. Frank on March 3, 2026, at approximately 8:30 a.m., PG&E encountered a technical issue with FERC's eLibrary that prevented us from uploading Enclosure 1 of the report, despite multiple attempts using different file formats and sizes. To meet the filing deadline, PG&E proceeded with submitting the cover letter and Enclosures 2 and 3. PG&E has contacted FERC Online Support and is awaiting further direction on resolving the upload problem. So far, the solutions they recommended have not been successful. Per Ms. Frank's guidance, this email includes a link to the complete report materials, including Enclosure 1. In addition, Ms. Frank recommended that PG&E submit a hard-copy version of the report. Please confirm the mailing address in response to this email, and I will get a hard copy sent your way. Please let us know if there are any additional steps you would like us to take in the interim or if there is another way to eFile this report, such as ESFT. We appreciate your assistance and flexibility as we work to complete the filing. Agency Share - Butte Creek FYLF Kindly, Sky Ramirez-Doble He/Him/His Hydro License Coordinator I Power Generation Pacific Gas & Electric Company c: (530) 250-7002 e: s9rv@pge.com From: Andrea Claros <Andrea.ClarosPferc.gov> Sent: Tuesday, March 3, 2026 9:37 AM To: Ramirez-Doble, Sky <S9RVfflpge.com> Cc: Drummond, Duncan <DGDI-IApge.com>; Joseph, Matthew <MWJAPpge.com> Subject: RE: [External] DeSabla Centerville (FERC No. 803) — FYLF Annual Report Filing Issue This email came from outside PG&E. Think before you click. Be extra wary of links, attachments, providing sensitive information, and QR Codes. If this email seems suspicious, use the REPORT PHISH BUTTON. Hello Sky, Thanks for giving us a heads up of this issue. I would recommend refiling the whole package, with a note in the cover letter explaining that it replaces the previous filing. But if for some reason you prefer, you can also file Enclosure 1 as a supplement to the previous filing, as long as the cover letter is clear in explaining such. If you need any technical help with elibrary you can contact FERC Online Support Hours of Operation 8:00 -5:00 ET I TTY: 202-502-8659 Telephone: 202-502-6652 Toll-free Telephone: 1-866-208-3676 Email: ferconlinesupport@ferc.gov Thanks https://outlook.office.com/mail/inbox/id/AAkALgAAAAAAHYQDEapmEc2byACqAC%2FEWg0ArOGO/02FVov3UOJktS6GcZCWgAHNeC04AAA?native...2/3 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 3/4/26. 12:51 PM Inbox - Drummond, Duncan - Outlook Andrea Claros, Chief Aquatic Resources Branch Federal Energy Regulatory Commission Office of Energy Projects Division of Hydropower Administration and Compliance 202-502-8171 From: Ramirez-Doble, Sky <S9RV_Rpge.com> Sent: Tuesday, March 3, 2026 11:24 AM To: Andrea Claros <Andrea.Clarosffiferc.gov> Cc: Drummond, Duncan <DGDHftpge.com>; Joseph, Matthew <MWJA(Jpge.com> Subject: [External] DeSabla Centerville (FERC No. 803) — FYLF Annual Report Filing Issue ,1 Caution: This message does not originate from a known FERC email system. Use caution if this message contains attachments, links or requests for information. Dear Ms. Claros, I am writing to inform you of a technical issue we encountered while filing the Annual Foothill Yellow-Legged Frog (FYLF) Monitoring Report for the DeSabla-Centerville Project, FERC No. 803, which was due yesterday in accordance with the Commission's August 15, 2025, Order. We were able to successfully upload the cover letter and Enclosures 2 and 3 to FERC's eLibrary. However, despite multiple attempts, we were unable to upload Enclosure 1 due to a persistent system error. We attempted several troubleshooting measures, including reducing file size, splitting the document, and converting the file into multiple formats (Word, PDF, TIFF, and JPEG), but encountered the same error each time. To meet the filing deadline, we proceeded with submitting the materials that could be uploaded. Enclosure 1 is complete and ready for filing, and we intend to submit it as soon as the technical issue is resolved. If there is a preferred alternative method for submitting the remaining enclosure, or if you would like us to re-file the full package once the issue is resolved, please let us know. We wanted to proactively flag this issue for the record and ensure the Commission is aware that the delay is due solely to a technical filing problem, not the completeness of the report. Please let me know if you have any questions or would like additional information. Kindly, Sky Ramirez-Doble He/Him/His Hydro License Coordinator I Power Generation Pacific Gas & Electric Company c: (530) 250-7002 e: s9rv@pge.com You can read about PG&E's data privacy practices at PGE.com/privacy.. https://outlook.office.com/mail/inbox/id/AAkALgAAAAAAHYQDEapmEc2byACgAC%2FEWg0ArOGv%2FVov3UOJktS6GcZCWgAHNeC04AAA?native...3/3 Document Accession #: 20260309-0002 Filed Date: 03/09/2026 Document Content(s) DocBatch260309-0002.pdf ..................................................1 Document Accession #: 20260309-0002 Filed Date: 03/09/2026