Fish Passage Feasibility Assessment Bowman Dam Hydroelectric Project (FERC No. P-14791) Prepared for: Ochoco Irrigation District Prepared by 15250 NE 95th Street Redmond, WA 98052 April 2020 Fish Passage Feasibility Assessment for Bowman Dam Hydroelectric Project (FERC No. P-14791) Prepared for: Ochoco Irrigation District 1001 NW Deer St. Prineville, Oregon 97754 Prepared by: R2 Resource Consultants, Inc. 15250 NE 95th Street Redmond, WA 98052 April 2020 CONTENTS INTRODUCTION ......................................................................................................................... 1 BACKGROUND ........................................................................................................................ 1 PROJECT SETTING AND FISH PASSAGE CONSIDERATIONS ................................................................. 1 STUDY SCOPE OF WORK ........................................................................................................... 4 METHODS .................................................................................................................................. 5 REVIEW OF EXISTING BIOLOGICAL INFORMATION .......................................................................... 5 REVIEW OF SITE AND ENGINEERING INFORMATION ........................................................................ 5 DESIGN CRITERIA....................................................................................................................... 6 BIOLOGICAL CRITERIA .............................................................................................................. 6 Anadromous Species for Passage Consideration .................................................. 6 FISH RUN PERIODICITY AND PLANNING LEVEL RUN SIZES ................................................................ 6 Adult Upstream Migration Timing ......................................................................... 6 Adult Upstream Planning Level Run Sizes ............................................................. 8 Smolt Downstream Migration Timing ................................................................... 9 Juvenile Downstream Passage Preliminary Run Size Estimates to Assess Passage Facilities.................................................................................................. 10 FISH PASSAGE CRITERIA AND LAWS .......................................................................................... 11 Fish Passage Laws ................................................................................................ 11 Fish Passage Criteria and Guidelines ................................................................... 11 Fish Passage Design Flows ................................................................................... 12 FACILITY INFORMATION AND RELEVANT FISH PASSAGE DATA .............................................. 13 CROOKED RIVER BASIN AND ASSOCIATED FACILITIES .................................................................... 13 OID Overview ....................................................................................................... 15 BOWMAN DAM DESCRIPTION ................................................................................................. 18 Existing Dam and Reservoir ................................................................................. 18 Proposed Hydropower Project ............................................................................ 24 Bowman Dam System Operations, Flows, and Reservoir Elevation Data ........... 27 General Overview of Operations ........................................................... 27 R2 Resource Consultants, Inc. Page | iii 2267/Bowman Fish Passage Feasibility Study April 2020 Exceedance Flow Summaries by Month, outflow immediately below Bowman Dam ............................................................................. 29 Exceedance Flow Summaries by Month, Inflow to Prineville Reservoir ................................................................................................ 31 Flood Flow Conditions below Bowman Dam ........................................ 33 Reservoir Elevations and Annual Fluctuation ....................................... 34 Storage Elevation Curve ........................................................................ 37 Bowman Dam Discharge Curves ........................................................... 38 Fish Passage Design Information Summary ......................................................... 38 Upstream Passage Design Flows and Tailwater Elevations .................. 38 Upstream Passage Reservoir Design Elevations ................................... 40 Downstream Fish Passage Design Flows ............................................... 40 Downstream Passage Reservoir Design Elevations ............................... 41 FISH PASSAGE OPTIONS .......................................................................................................... 43 OPTIONS FOR UPSTREAM PASSAGE .......................................................................................... 44 UP #1 – Volitional Passage at Bowman Dam, Fish Ladder .................................. 44 Description and Technical Considerations ............................................ 44 Biological and Technical Considerations ............................................... 49 Opinion of Probable Construction Cost ................................................ 50 Opinion of Probable Annual O&M Costs ............................................... 50 Implications to OID operations ............................................................. 50 UP #2 – Collection-and-Transport at Bowman Dam ........................................... 51 Description and Technical Considerations ............................................ 51 Biological and Technical Considerations ............................................... 57 Opinion of Probable Construction Cost ................................................ 58 Opinion of Probable Annual O&M Costs ............................................... 58 Implications to OID operations ............................................................. 58 UP #3 – Collection-and-Passage at Bowman Dam with Whooshh System. ........ 58 Description and Technical Considerations ............................................ 58 Biological and Technical Considerations ............................................... 60 Opinion of Probable Construction Cost ................................................ 61 R2 Resource Consultants, Inc. Page | iv 2267/Bowman Fish Passage Feasibility Study April 2020 Opinion of Probable Annual O&M Costs ............................................... 61 Implications to OID operations ............................................................. 61 UP #4 – Collection-and-Transport from Downstream Location at Pelton Round Butte Project ............................................................................................ 61 Description and Technical Considerations ............................................ 61 Biological and Technical Considerations ............................................... 62 Opinion of Probable Construction Cost ................................................ 62 Opinion of Probable Annual O&M Costs ............................................... 62 Implications to OID operations ............................................................. 63 UP #5 – Collection-and-Transport from Downstream Location at Opal Springs Dam ......................................................................................................... 63 Description and Technical Considerations ............................................ 63 Biological and Technical Considerations ............................................... 63 Opinion of Probable Construction Cost ................................................ 64 Opinion of Probable Annual O&M Costs ............................................... 64 Implications to OID operations ............................................................. 65 OPTIONS FOR DOWNSTREAM PASSAGE ..................................................................................... 65 DN #1 – Volitional Passage through Bowman Dam Outlet, as Modified for Hydropower Project (No-action Alternative) ...................................................... 66 Description and Technical Considerations ............................................ 66 Biological and Technical Considerations ............................................... 67 Opinion of Probable Construction Cost ................................................ 67 Opinion of Probable Annual O&M Costs ............................................... 67 Implications to OID Operations ............................................................. 67 DN #2 – Volitional Passage through Multi-Port Bypass Helix .............................. 67 Description and Technical Considerations ............................................ 67 Biological and Technical Considerations ............................................... 68 Opinion of Probable Construction Cost ................................................ 69 Opinion of Probable Annual O&M Costs ............................................... 69 Implications to OID Operations ............................................................. 69 DN #3 – Volitional Passage through Screened Intake and Bypass at Bowman Dam .....................................................................................................