Prospect No. 3 Hydroelectric Project FERC Project No. P-2337 Updated Study Report: Fish Passage Facilities May 2016

Transcription

1 Prospect No. 3 Hydroelectric Project FERC Project No. P-2337 Updated Study Report: Fish Passage Facilities May 2016 Prepared by: Alden Research Laboratory, Inc Willows Road NE Redmond, WA And Meridian Environmental, Inc Westlake Ave. N. Seattle, WA For Public Review

2 Prospect No. 3 Hydroelectric Project FERC Project No. P-2337 Updated Study Report: Fish Passage Facilities May 2016 Volume I: Physical Evaluation Prepared by: Alden Research Laboratory, Inc Willows Road NE Redmond, WA And Volume II: Biological Evaluation Prepared by: Meridian Environmental, Inc Westlake Ave. N. Seattle, WA 98109

3 Prospect No. 3 Hydroelectric Project FERC Project No. P-2337 Updated Study Report: Fish Passage Facilities May 2016 Volume I: Physical Evaluation Prepared by: Alden Research Laboratory, Inc Willows Road NE Redmond, WA 98052

4 Solving flow problems since 1894 Prospect No. 3 Hydroelectric Project FERC Project No. P-2337 Updated Study Report Fish Passage Facilities: Physical Evaluation Prepared for: PacifiCorp 925 South Grape Street Medford, OR ALDEN Research Laboratory, Inc /phone /fax 9521 Willows Road NE, Redmond, WA info@aldenlab.com

5 TABLE OF CONTENTS 1.0 Introduction Background Study Description Study Objectives Upstream (Fish Ladder) and Downstream (Fish Screen) Criteria Instrumentation, Measurement, and Methods Water Surface Elevations Water Depths Physical Attributes Jump Heights Velocities Weir Notch Velocities Submerged Orifice Velocities Fish Return Bypass Entrance Velocity Fish Screen Velocities Flows Fish Ladder Weir Flows Fish Return Bypass Flow Fish Screen Flow Upstream Canal Flow Energy Dissipation Test Conditions Targeted Test Conditions Low Flow Evaluation Conditions High Flow Evaluation Conditions Structure Performance Jump Heights Entrance, Exit, and Weir Notch Velocities Fish Return Bypass Entrance Velocity Weir Notch Depth i

6 4.5 Entrance Pool and Jump Pool Depths Energy Dissipation Fish Ladder Exit Flow Rating Curve Physical Inspection Fish Screen Flows Fish Screen Sweeping Velocity Fish Screen Approach Velocity Ratio of Sweeping to Approach Velocity Physical Conditions of the Fish Screen Summary, Conclusions, and Recommendations Summary and Conclusions Fish Ladder Fish Screen Recommendations Fish Ladder Fish Screen References ii

7 List of Tables Table 1 Description of Physical Fish Ladder Parameters... 7 Table 2 Description of Physical Fish Screen Parameters... 7 Table 3 Fish Ladder Jump Heights Table 4 Weir Notch Velocities Table 5 Measured Weir Notch Depths Table 6 Average Pool Depths Table 7 Energy Dissipation Factor Table 8 Pre-Maintenance Sweeping Velocity Measurements (ft/s) - Low Flow Conditions.. 40 Table 9 Pre-Maintenance Sweeping Velocity Measurements (ft/s) - High Flow Conditions. 41 Table 10 Post-Maintenance Sweeping Velocity Measurements (ft/s) - High Flow Conditions Table 11 Pre-Maintenance Approach Velocity Measurements (ft/s) - Low Flow Conditions.. 43 Table 12 Pre-Maintenance Approach Velocity Measurements (ft/s) - High Flow Conditions. 43 Table 13 Post-Maintenance Approach Velocity Measurements (ft/s) - High Flow Conditions Table 14 Pre-Maintenance Ratio of Sweeping to Approach Velocity - High Flow Conditions Table 15 Post-Maintenance Ratio of Sweeping to Approach Velocity - High Flow Conditions Table 16 Summary of Fish Ladder Measurements and OAR Requirements Low Flow Table 17 Summary of Fish Ladder Measurements and OAR Requirements High Flow iii

8 List of Figures Figure 1 Location of Prospect 3 Hydroelectric Project... 1 Figure 2 Fish Ladder Pool and Weir Numbering... 8 Figure 3 Fish Screen Measurement Locations During Low Flow... 9 Figure 4 Fish Screen Measurement Locations During High Flow Figure 5 Flow Correlation Between Big Butte Creek and South Fork Rogue Figure 6 Flow Correlation Between Rivers During the High Flow Evaluation Figure 7 South Fork and Bypass Flows During the Initial High Flow Measurements Figure 8 Initial High Flow Evaluation Bypass Design Flow Curve Compared to Measurement Figure 9 Fish Ladder Exit Rating Curve iv

9 List of Photos Photo 1 Prospect 3 Fish Ladder and Bypass Canal (High Flow)... 3 Photo 2 Fish Screen (Looking Upstream) in a Dewatered Condition Before Pressure Washing Photo 3 Fish Screen at High Flow (Looking Downstream)... 5 Photo 4 Measurement of Freeboard During the High Flow Evaluation Photo 5 PLC Display at Peak Flow During the High Flow Evaluation Photo 6 Measuring Water Depth Over Weir Photo 7 Weir Notch Velocity Measurement Over Weir Photo 8 Sontek FlowTracker ADV (Side Looking Probe) Photo 9 Nortek Vectrino Cabled Lab Probe ADV (Down Looking Probe) Photo 10 ADV Deployment During the Low Flow Evaluation Photo 11 ADV Deployment During the High Flow Evaluation Photo 12 ADV Pointing at Screen During the High Flow Evaluation Photo 13 Example of Direct Flow Path Between Weirs Photo 14 Flow Over Weir 7 During the High Flow Evaluation Photo 15 No Spill During the Low Flow Evaluation Photo 16 River Conditions During the Low Flow Evaluation (Looking Downstream) Photo 17 Dam Spill and Canal Flow During High Flow Conditions Photo 18 River Conditions During High Flow Evaluation (Looking Downstream) Photo 19 Stem Positions During High Flow Measurements Photo 20 Physical Inspection: Weirs 14 and Photo 21 Fish Screen Assembly During June, 2015 Maintenance Activities v

10 1.0 Introduction PacifiCorp plans to file an application for a new license to continue operating the Prospect No. 3 Hydroelectric Project (Project), Federal Energy Regulatory Commission (FERC or Commission) Project No. P-2337, on the South Fork Rogue River in Jackson County, Oregon. The current license was issued on January 30, 1989 for a period of thirty years, expiring on December 31, As part of FERC s Integrated Licensing Process (ILP), a study to assess the effectiveness of the existing fish passage facilities was initiated during the summer of PacifiCorp personnel conducted a hydraulic assessment of the fish passage facilities under low flow conditions in July-August of Alden Research Laboratory (Alden) was retained under contract to complete the hydraulic assessment during high flow conditions. The initial high flow condition measurements were made in January of 2015, followed by a post-maintenance evaluation of the fish screen on February 1 st of The results of both the low and high flow assessments, including the pre- and post-maintenance evaluations of the fish screen, are included in this report. 1.1 Background The Project is located at river mile 10.5 on the South Fork Rogue River, east of the unincorporated community of Prospect in northeast Jackson County, Oregon (Figure 1). Figure 1 Location of Prospect 3 Hydroelectric Project 1

11 The Project includes a 172-foot-long, 24-foot-high concrete diversion dam with a 98-foot-long un-gated ogee spillway, and contains both upstream and downstream fish passage facilities. The Project produces 7.2 megawatts (MW) and is operated as a run-of-river hydroelectric facility. PacifiCorp maintains a water right in perpetuity from the State of Oregon for 150 cubic feet per second (cfs) from the South Fork Rogue River and is currently required to maintain a continuous minimum flow of 10 cfs in the river downstream of the Project, or to return all available inflow to the downstream river channel if less than the required minimum. Bypass flows are measured and recorded at USGS gaging station , located approximately 0.3 miles downstream of the diversion dam at river mile The upstream fish passage facility (fish ladder) includes an 86-foot-long, 15-pool concrete pooland-weir type fish ladder for upstream fish passage past the diversion dam. This ladder was originally constructed in 1931 and has been modified twice, once in 1973 and again in The downstream fish passage facility (fish screen) was constructed in 1996 to address downstream fish passage concerns. This facility consists of a 0.25-inch wedge-wire, inclined plane fish screen with an effective surface area of square feet located within the Project waterway. Baffles were installed after the 1998 hydraulic assessment to create a more uniform flow through the screen. However, at the time of the initial high-flow assessment (January 2015), the baffles were not present. In June of 2015, PacifiCorp installed an improved baffle design, which permanently mounted the baffles behind the screen. Fish moving down the bypass canal and past the fish screen are directed to an 18-inch diameter bypass pipe that transports them to Pool 6 of the fish ladder. This flow is used to increase the attraction flow to the fish ladder. An overview of the Project facilities is provided in Photo 1. The fish screen is shown in a dewatered condition in Photo 2, and operating during a high flow event in Photo 3. 1 The total effective screen area includes only the area of screen available to pass flow. This does not include structural obstructions such as the 2.5-inch wide solid steel and rubber gasket perimeter. 2

12 South Fork Rogue River downstream of diversion dam Inclined fish screen 18-inch fish return pipe discharging into Pool 6 Bypass canal Ultrasonic water level gauge Pool 6 Pool 1 Pool 14 Photo 1 Prospect 3 Fish Ladder and Bypass Canal (High Flow) 3

13 Bypass canal transition from trapezoidal to rectangular crosssection Stainless steel structural screen edging with rubber gasket fitted to concrete wall Photo 2 Fish Screen (Looking Upstream) in a Dewatered Condition Before Pressure Washing. 4

14 Downstream of fish screen control gate Downstream fish screen water level gauge Upstream fish screen water level gauge Diversion canal at High Flow Photo 3 Fish Screen at High Flow (Looking Downstream) 1.2 Study Description During the Pre-Application Document (PAD) preparation, it was identified that an assessment of fish passage facilities effectiveness was last conducted in July On April 28, 2014, PacifiCorp filed a Revised Study Plan in fulfillment of the requirements of 18 CFR 5.11 of the 5

15 FERC ILP. FERC issued a study plan determination on May 27, 2014 approving the fish passage facilities study plan with FERC staff-recommended modifications. The hydraulic assessment of the existing Project fish passage facilities was to be conducted for both the fish ladder (upstream passage) and fish screen (downstream passage) as described in the Study Plan (PacifiCorp, 2014) and FERC study plan determination. The hydraulic parameters of the fish passage facilities vary with river flow, so the assessment was conducted during both low and high flow periods. Per OAR , fishway design must accommodate fish passage over a range of flows, from the 5 th to the 95 th percentile exceedance flows, 444 cfs and 60 cfs, respectively, for the South Fork Rogue at the Project diversion dam. The flows at the Project are calculated by the summation of the flow in the diversion canal plus the flow measured at the downstream gage (USGS Gage ). Field operations for these studies were planned to correlate as closely as possible to the 5 th and 95 th percentile exceedance flows. 1.3 Study Objectives The goal of the study was to evaluate the hydraulics of the existing fish passage facilities as they relate to passage of resident trout upstream and downstream of the Project diversion dam and to determine if key physical parameters are in compliance with Oregon fish passage criteria (ODFW, 2015) The Study Plan objectives were to: 1. Evaluate physical parameters of the upstream passage facility; 2. Evaluate the upstream fish passage hydraulic conditions; 3. Evaluate physical parameters of the downstream passage facility; and 4. Evaluate the screening facility hydraulic conditions. 1.4 Upstream (Fish Ladder) and Downstream (Fish Screen) Criteria PacifiCorp adopted the physical parameters recommended for assessment by ILP participants. These parameters were selected because they are important to effective fish passage. The physical characteristics recommended by ILP participants are summarized in Table 1 and Table 2. Where direct measurements of the parameters could not be accurately or safely measured, best professional judgment (BPJ) and indirect methods using accepted hydraulic relationships were used. In addition to the hydraulic characteristics of the fish ladder, the physical condition of the fish ladder was evaluated during Alden s initial high flow evaluation. Figure 2 shows a plan view of the fish ladder and illustrates the numbers used to denote the pools and respective weirs. Figure 3 shows a plan view of the fish screen and the measurement locations reported for the low flow evaluation. Figure 4 shows the measurement locations used during the high-flow evaluations. 6

16 Parameter Jump heights Table 1 Entrance, Exit, and Weir Notch Velocities Weir Notch Depth Entrance Pool and Jump Pool Depth Energy Dissipation Flow Structure Condition Parameter Table 2 Approach and Sweeping Velocity (components) Description of Physical Fish Ladder Parameters Reason OAR stipulates that the maximum difference between the upstream and downstream water surface elevations shall not exceed 6 inches. Elevated jump heights may delay upstream passage OAR provides that flow velocities at any discrete fishway transition may not exceed 8 feet per second. High velocities may hinder fish from entering or exiting fishway. OAR provides that water depth at any location through which adult fish must swim must be at least 12 inches. Criteria do not apply to weir crests over which fish must jump. OAR provides that pools with a water depth of at least 2 feet must be located downstream of any point where which fish must jump to move upstream. OAR provides energy dissipation criteria to ensure pools have sufficient volume to facilitate the effective upstream movement of fish. Hydraulic parameters vary with flow. A fishway is most effective when it is adequately maintained as designed. Description of Physical Fish Screen Parameters Reason Appropriate approach velocities minimize impingement or contact with the screen. Sweeping velocities affect the rate at which fish are transported along the face of the screen and into the bypass. Sweeping velocities should be higher than approach velocities. Total Flow through the To provide a description of existing conditions at the fish screen. Fish Screen (FERC, 2014) Velocity at the Entrance to To provide a description of existing conditions at the entrance to the Fish Return Bypass the bypass. (FERC, 2014) Bypass Flow (FERC, 2014) To provide a description of existing conditions at the bypass. Structure Condition The bypass system is most effective and safe when it is adequately maintained as designed. 7

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20 2.0 Instrumentation, Measurement, and Methods Determination of the parameters noted in Table 1 and Table 2 requires the physical measurement of water surface elevations, water depths, other physical attributes such as lengths, widths, and depths of walls or screens, and the measurement of water velocities. 2.1 Water Surface Elevations Water surface elevations at high flows were measured indirectly through the physical measurement of freeboard to a known or common datum, such as a horizontal surface near the water surface. Fish ladder pool elevations were measured at all fifteen pools to determine pool jump heights. Photo 4 shows the technique used for the measurements. While using this technique, care was taken to measure the freeboard away from the presence of localized water boils and near a relatively calm water surface. Measurements of this type are expected to be accurate to within ± 1/8-inch. Jump heights at low flow were measured with a staff gage on the downstream wall of each pool immediately adjacent to the weir notch, with the bottom of the staff at the lower pool surface elevation. Photo 4 Measurement of Freeboard During the High Flow Evaluation Reporting of water surface elevations with respect to the mean sea level was made possible through the water surface elevation measurements conducted using ultrasonic water level gauges. The Project incorporates six of these gauges into the Programmable Logic Control (PLC), otherwise known as the PI System. Photo 5 shows the PLC display at the peak of flow on 11

21 January 18 th, Measurements of this type are expected to be accurate to within ± 1/8-inch (approximately 0.01 feet). Photo 5 PLC Display at Peak Flow During the High Flow Evaluation 2.2 Water Depths Water depths were measured in all fish ladder pools during high flows using a telescoping survey rod, as shown in Photo 6. During high flows, this technique was used to measure both the flow depth over the fish ladder weirs and the depth in all four corners and center of each fish ladder pool. Measurements of this type are expected to be accurate to within ± 0.1 feet (approximately 1-1/4 inch). The level of accuracy was deemed acceptable based on the general level of turbulence present during the high flow evaluation. During low flows a Hondex PS-7 portable depth sounder was used to measure the pool depths to an accuracy of ± one percent. 12

22 Bypass return flow Pool 6 Pool 5 Water depth over weir 5 Pool Physical Attributes Photo 6 Measuring Water Depth Over Weir 5 The geometry of each pool was measured using a standard tape measure for later use in calculations of pool volume and, subsequently, energy dissipation. A tape measure was also used for determination of the fish bypass exit conditions. The following measurements were collected for each fish ladder pool: upstream pool width; downstream pool width; right hand pool length; left hand pool length; pool depth in each corner; center pool depth; weir depth; weir width; notch velocity; water depth over weir; wall thickness between pools; upstream freeboard; and downstream freeboard. 13

23 2.4 Jump Heights Jump heights were calculated as the distance between water heights upstream and downstream of the weirs. 2.5 Velocities Velocities were measured in front of the fish screens, at the entrance to the fish return bypass, and in the ladder over weir notches. Velocities were also calculated by dividing flow rates by flow areas. PacifiCorp implemented a replacement fish screen baffling system in June 2015 to improve the velocity distribution in front of the screens. Following implementation of the baffling system, velocity measurements were repeated for high flow conditions using Alden s techniques described in the following sections Weir Notch Velocities Fish ladder weir notch velocities were only measured during the high flow evaluation. In variance of the Acoustic Doppler Velocimeter (ADV) prescribed by the approved Study Plan methodology for hydraulic parameters (Study Plan 7.1.2), a propeller-type velocity meter manufactured by Global Water was inserted along the center of flow at the mid-depth location at each weir to record velocities. The Global Water probe is better suited to collect weir notch velocities due to a calibrated depth gauge being integrated into the meter, which facilitated placement of the probe. The instrument reported an average velocity over a 60-second sampling duration. This technique, being applied at Weir 7 is shown in Photo 7. Weir notch velocities for the low flow evaluation were determined by calculating the average velocity over each weir using Equation 1. This technique was also used as a check on the velocities measured using the Global Water Probe during the high flow evaluation. V wwww = Q BB (Equation 1) Where: V weir =Velocity (ft/s) Q = Flow (cfs) B = Width of the weir (ft) H = Head on the weir (ft) Weir notch velocities recorded with the Global Water probe were accurate to within ± 0.1 ft/s, however placement at the mid-depth location was difficult and may have contributed to larger recorded errors, on the order of ± 0.5 ft/s. 14

24 Photo 7 Weir Notch Velocity Measurement Over Weir Submerged Orifice Velocities The upstream fish ladder exit is a submerged rectangular opening (2.5 ft. x 1.3 ft) oriented near the bottom of the river. The average exit velocity was calculated by dividing the flow through the exit (the same flow as that passing over Weirs 7 through 15 the upper section) by the open orifice area. For practical considerations, it was assumed that there was negligible blockage of the orifice by debris Fish Return Bypass Entrance Velocity Bypass entrance velocities were recorded with the Global Water probe and are assumed to be accurate to within ± 0.5 ft/s, based on probe placement. The velocity was recorded in the bypass channel at the terminus of the fish screen. Due to practical limitations for probe deployment, repeat measurements were collected within the flow area at the entrance, and engineering judgment was utilized to select the measured velocity representative of the average for the flow. The selected location of the measurement was along the centerline of the channel near middepth. 15

25 2.5.4 Fish Screen Velocities Fish screen approach (V a ) and sweeping (V s ) velocity components were measured using acoustic-doppler velocimeters (ADVs). PacifiCorp used a Sontek FlowTracker (Photo 8) and Alden used a Nortek Vectrino (Photo 9) during the low and high flow evaluations, respectively. Both evaluations recorded velocities at 28 positions, as previously illustrated in Figure 3 and Figure 4. Differences in measurement location and distance from the screen were a result of differing deployment techniques. PacifiCorp utilized a vertical rod deployment stanchion, holding the side-looking ADV pointed vertically away from the screen. The deployment rod allowed a near perpendicular placement with respect to the screen face. and placed the measurement volume approximately 5-inches from the screen face. The rod was hand-held from an inflatable boat, which was rigged to a center guide wire (Photo 10). Alden deployed a down-looking ADV from a stanchion constructed of steel plate and open rectangular tube (Photo 11), such that flow disturbances were minimized. The stanchion had a pivot point located 6-inches from the base which included a foot-pad to rest on the screen face and locate the ADV such that the Z-axis was pointed perpendicular to the screen and the measurement volume was located 1-inch from the floor and approximately 2-inches upstream of the stanchion (Photo 12). In addition to the 28 screen velocities recorded, Alden also measured velocities at 20 equally spaced locations on a grid along a transect approximately 2-feet upstream of the screen to calculate the flow entering the screened portion of the canal. The ADV measures three components of velocity on a Cartesian coordinate system. Both deployments utilized instrument hardware to orient the Z-axis of the probe with the vector normal to the screen face, thus recording the approach velocity directly. The sweeping velocity was determined as the resultant of the remaining two components. Data recorded for each velocity component were time-based averages over durations sufficient to reach a stabilized average measurement (typically 1-2 minute durations). 16

26 Photo 8 Sontek FlowTracker ADV (Side Looking Probe) Photo 9 Nortek Vectrino Cabled Lab Probe ADV (Down Looking Probe) 17

27 Photo 10 ADV Deployment During the Low Flow Evaluation Photo 11 ADV Deployment During the High Flow Evaluation 18

28 Photo 12 ADV Pointing at Screen During the High Flow Evaluation 2.6 Flows The flows in the fish ladder were divided into two sections an upper and lower. In the upper section, consisting of Pools 15 through 7, flow enters via the submerged exit orifices 2. The flow in the upper section is combined with the flow from the fish return bypass in Pool 6; resulting in the flow through the lower section, Pool 6 through Fish Ladder Weir Flows The weirs passing flow through most pools are aligned on the same axis and most operate in a submerged condition during high flow, as shown Photo 13. An exception is Pool 6 and 7, which are turning pools, re-directing the flow direction 90 degrees each. Pool 6 also contains the inflow from the fish screen bypass (Photo 14). Flow passing over Weir 7 (combining with the bypass flow) was not submerged, so Equation 2 (the standard weir equation) provides an estimate of the flow passing over the weir. 2 Typically only one orifice is open at a time. 19

29 Photo 13 Example of Direct Flow Path Between Weirs Photo 14 Flow Over Weir 7 During the High Flow Evaluation 20

30 2.6.2 Fish Return Bypass Flow During the low flow evaluation (a period of no dam spill), the flow in the fish (screen) return bypass pipe was determined by calculating the difference between flow recorded at the U.S. Geological Survey gaging station 0.25 miles downstream from the dam (USGS Gage ) and the calculated flow over Weir 7. During the initial high flow evaluation, the bypass flow was calculated from velocities and flow depths measured both at the entrance and the exit of the bypass pipe. These measured flows were compared to the design curve for the bypass, based on a discharge coefficient of 3.09, as determined from design data provided by MWH in their 1997 memo to PacifiCorp (MWH, 1997). Where: Q = Flow (cfs) C d = discharge coefficient (3.2 used) B = Width of the weir (ft) H = Head on the weir (ft) Q = C d BH 1.5 (Equation 2) 2.7 Fish Screen Flow During the initial high flow evaluation, the flow through the fish screen was determined using two methods. The first method multiplies the average of all twenty-eight direct screen approach velocity measurements by the effective available screen area (193.3 ft 2 ) using Equation 3. Where: Q = Flow (cfs) V average = velocity average (fps) A = area (ft 2 ) The second method is to use the measured downstream canal flow. 2.8 Upstream Canal Flow Q = V aaaaaaa A (Equation 3) During the initial high flow evaluation, the upstream canal flow (downstream of the side-spill overflow weir) was determined using three methods. The first method is to add the downstream canal flow to the fish return bypass flow. The second method is to add the calculated fish screen flow (Equation 3) to the fish return bypass flow. The third method is to use Equation 3 with a 20-21

31 pt. grid of stream-wise velocity measurements and the total cross-sectional area of the canal at the transect where measurements were recorded. 2.9 Energy Dissipation The energy dissipation factor (EDF) is a measure of turbulence associated with energy dissipation in each pool. The EDF in each pool was calculated using Equation 4. To meet the requirements provided in OAR , EDF must be less than or equal to 4 pound force per square foot second. EEE = www V (Equation 4) Where ; V = is the water volume in cubic feet w = is 62.4, the unit weight of water, in pounds per cubic foot Q = is the fish ladder flow in cubic feet per second H = is the energy head of pool-to-pool flow in feet 22

32 3.0 Test Conditions 3.1 Targeted Test Conditions Tests were targeted for periods when the total river flows approximated the 5th and 95th percentile exceedance flows, 444 cfs and 60 cfs respectively. The total river flows are determined by adding the flow in the diversion canal to the flow measured downstream of the Project at the U.S. Geological Survey gaging station 0.25 miles downstream from the dam (USGS Gage ). These flows represent two different operating regimes for the diversion and fish passage facilities. For the low flow regime the total river flow would enter the diversion, with no flow passing over the project spillway. The diversion canal flow control gates, one upstream and a second downstream of the fish screen, would be manipulated to maintain a minimum of 10 cfs flow in the fish ladder at and below Pool 6 (or the full project inflow if less than 10 cfs). The remaining flow would be passed down the diversion canal downstream from the fish screens up to the maximum water right of 150 cfs. For the high flow regime, flow in excess of the 150 cfs water right and the minimum 10 cfs in the fish ladder at and below Pool 6, would be passed over the spillway, with minor increases in the fish ladder and screen bypass pipe flows as dictated by the project impoundment water surface elevation and the ladder and bypass operational requirements to deliver safe fish passage conditions. 3.2 Low Flow Evaluation Conditions The hydraulic analysis of the fish passage facilities under low flow conditions at the Project were measured by PacifiCorp. The targeted 95 th -percentile exceedance flow conditions were 10 cfs exiting the ladder and 50 cfs in the canal. PacifiCorp measured the jump heights in the fish ladder on June 1, 2014 and the remaining hydraulic parameters on July 2, The hydraulic conditions on these two days were very similar and represent no spill conditions. The total Project flow on July 2, 2014 was 104 cfs, with 14 cfs exiting the ladder and entering the South Fork, while this is greater than the 95 th -percentile exceedance flow, the conditions in the fish ladder are expected to be sufficiently similar to the targeted flow condition. The flow at the fish ladder exit was calculated by PacifiCorp to be 2.0 cfs, resulting in 12 cfs in the bypass. The Dam and Spillway are visible in Photo 15, and the resulting downstream river conditions are presented in Photo 16, where the only downstream flow is from the fish ladder. 23

33 Photo 15 No Spill During the Low Flow Evaluation Photo 16 River Conditions During the Low Flow Evaluation (Looking Downstream) 24

34 The hydraulic conditions in the fish screen were measured on August 20, The diversion canal flow was 51 cfs and the downstream South Fork River flow exiting the ladder was 16 cfs. 3.3 High Flow Evaluation Conditions The Study Plan indicates that high flow assessments would occur in May or June when snowmelt runoff contributes to relatively high flows. The FERC study plan determination was received on May 27, 2014, and after that time, flows were already significantly lower than the 5% exceedance flow. Therefore, PacifiCorp sought to target high flow events between January and March 2015 to provide study results and reporting in the first study season (May 2014 to May 2015) as required by the Study Plan. Based on the findings from the fish screen evaluation during the first study season (presented below), in June 2015, PacifiCorp conducted maintenance improvements to the fish screen in the form of an improved baffle system behind the fish screen bars. Post-maintenance, high-flow, hydraulic conditions at the fish screen were re-evaluated in February of Both sets of highflow evaluations are presented below. High flow events on the South Fork of the Rogue River tend to be very flashy, with rapidly changing flows and short peak durations which made it very difficult to predict a period when the rivers flow would match the 5% exceedance condition of 444 cfs. A good correlation exists between the timing of the peak flows in the South Fork (USGS Gage ) and Big Butte Creek near McLeod, OR (USGS gage ), as is illustrated in Figure 5. These two gages are located approximately 15 miles apart. NOAA s Northwest River Forecast Center predicts future flows in Big Butte Creek which allowed Alden to use these predictions as a surrogate for the river flows at the Project. 25

35 South Fork (USGS ) Big Butte (USGS ) RIver Flow (cfs) Date Figure 5 Flow Correlation Between Big Butte Creek and South Fork Rogue Based on predicted high flow events for Big Butte, Alden measured the fish screen hydraulics on January 17 th, 2015 (pre-maintenance activities) and February 1 st, 2016 (post-maintenance activities). The fish ladder hydraulics were measured on January 18 th, The correlation between rivers during the initial high-flow evaluation period is provided in Figure 6. The flows in the South Fork and the diversion canal during the initial high-flow measurement period in the first study season are shown in Figure 7. During this period the diversion canal flow was held relatively constant at 150 cfs downstream of the fish screens, the maximum permitted diversion. This was the expected diversion canal flow during 5% exceedance flow conditions. A South Fork river flow of 294 cfs as measured at USGS gage was needed to reach the 5% exceedance conditions. As can be seen in Figure 7, the flow in the South Fork peaked at over 530 cfs at 2 PM on 01/18/2015. Post-maintenance fish screen measurements were conducted at a canal flow of approximately 120 cfs, with the South Fork inflow to the Project averaging 235 cfs. Photo 17 and Photo 18 show the dam, spillway condition, and respective downstream river hydraulics present during the high flow evaluation. White-water was present extending from the base of the spillway beyond view from the Project. 26

36 South Fork ( USGS ) Big Butte ( USGS ) Flow (cfs) Date_Time Figure 6 Flow Correlation Between Rivers During the High Flow Evaluation 27

37 South Fork ( USGS ) Diversion Canal Flow (cfs) Date_Time Figure 7 South Fork and Bypass Flows During the Initial High Flow Measurements 28

38 Photo 17 Dam Spill and Canal Flow During High Flow Conditions Photo 18 River Conditions During High Flow Evaluation (Looking Downstream) 29

39 The flow in the upper section of the fish ladder was calculated to be 8.0 cfs. During the initial high flow evaluation, the flow in the fish bypass was determined using measurements at the end of the fish screen to be 13.7 cfs. The bypass flow determined from the design curve correlation was 13.3 cfs. Figure 8 illustrates that the design curve is a good estimator of the actual flow in the bypass pipe. The total flow leaving the ladder and entering the South Fork was the sum of the upper section and the bypass flows (21.3 cfs). Using the design curve, the flow in the fish bypass during the post-maintenance evaluation was determined to be 17.1 cfs at water surface elevation of ft Design Flow Measured Flow Canal Water Surface Elevation (ft) Bypass Flow (cfs) Figure 8 Initial High Flow Evaluation Bypass Design Flow Curve Compared to Measurement 30

40 4.0 Structure Performance The following sections compare the measured performance with the OAR requirements. 4.1 Jump Heights Jump heights were calculated by measuring the distance between the water heights upstream and downstream of the weirs. These jump heights are compared to the OAR requirement in Table 3. None of the jumps, with the exception of the jump at Weir 2, meet OAR requirement for low flow. However at high flow, the OAR requirement is not always applicable. Under high flow conditions, all of the weirs except 7, 10, 12, and 13 are submerged allowing fish to swim over them without jumping. Comparing the velocity generated by the hydraulic drop through the weir notch and the flow depths available for swimming to the OAR requirements is applicable instead when the weir is submerged. Table 3 Fish Ladder Jump Heights Weir Number Jump Height (inches) Low Flow Meets OAR Requirement ( 6 inches) Jump Height (inches) High Flow Meets OAR Requirement ( 6 inches) NO 4.5 YES YES 1.5 YES NO 3.5 YES NO SUBMERGED NA NO SUBMERGED NA NO SUBMERGED NA NO 19.5 NO NO SUBMERGED NA NO SUBMERGED NA NO SUBMERGED NA NO SUBMERGED NA NO 17.0 NO NO 18.0 NO NO SUBMERGED NA NO SUBMERGED NA 6 3 Weir submerged; notch velocity and flow depth apply for swimming passage. 31

41 4.2 Entrance, Exit, and Weir Notch Velocities Velocities within the fish ladder were calculated for the low and high flow evaluations. In addition a direct measurement of a mid-depth velocity was made over the weir during the high flow evaluation. Velocities at the fish ladder exit were similarly calculated by dividing the estimated flow by the submerged area of the orifice 4. Water depths measured at the weir crests vary within the upper and lower fish ladder sections due to dissimilar approach hydraulics. As a result of these variations reported weir notch velocities vary among weirs with identical flows. All velocities reported in Table 4 are within the OAR maximum velocity of 8 ft/s. So, through a combination of submergence to allow swimming passage and velocities less than 8 ft/s, all of the weirs except 7, 10, 12, and 13 are passable at high flow either by jumping or swimming by OAR requirements, assuming the flow depths over the submerged weirs are enough to allow swimming. Table 4 Weir Notch Velocities Low Flow High Flow Weir Number Estimated Meets OAR Measured Estimated Meets OAR Velocity Requirement Notch velocity Velocity Requirement (ft/s) ( 8 ft/s) (ft/s) (ft/s) ( 8 ft/s) YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES The fish ladder exit is composed of two submerged adjustable height orifices. Standard operating procedure for the fish ladder exit is for one of the two exit orifices to be completely open and the other closed. Exit velocities were estimated using the flow in the upper fish ladder and the assumed open area of the orifice(s). 4 It was not possible to measure the width or depth of the submerged orifice. Area was determined through available design drawings. 32

42 One orifice was fully open and the other closed during the low flow measurements. Under this condition the velocity in the fish ladder exit was estimated to be 0.7 ft/s. During the high flow measurements one orifice was fully open and the second gate was opened approximately 7.5 inches 5. The gate positions were estimated by measuring the stem heights shown in Photo 19. In the positions shown, the increase in open area was estimated to increase from 3.2 sq. ft. to 4.03 sq. ft., with a resulting exit velocity of 2.0 ft/s. Photo 19 Stem Positions During High Flow Measurements 4.3 Fish Return Bypass Entrance Velocity The velocity at the entrance to the fish return bypass was measured using the Global Water probe. A time-averaged velocity of 5.4 ft/s was recorded. This velocity is lower than the OAR requirement of less than or equal to 8 ft/s for fish ladder flows. 4.4 Weir Notch Depth The water depths at the weir notches were directly measured under both the low and high flow conditions. The results of these measurements as compared to OAR requirements are shown in Table 5. Compliance with OAR requirements is based on a minimum water depth of 12 inches. This water depth is required at fishway locations where adult fish require passage. The OAR requirement is statewide and designed to cover fishways where adult salmon are present. The 5 Operators had opened the second orifice to compensate for stick debris partially blocking the first orifice. 33

43 South Fork Rogue River supports a coldwater fishery of predominantly rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis). Neither juvenile or adult salmon are present at the Project, therefore the OAR water depth requirement for fishways designed for juvenile fish passage may be a more appropriate standard. Where only juvenile fish are present the minimum water depth shall be 6 inches. The minimum water depth over all the fish ladder weirs was greater than 6 inches during both the low and high flow conditions. Table 5 Measured Weir Notch Depths Low Flow High Flow Weir Number Meets OAR Meets OAR Measured Depth Requirement Measured Depth Requirement (inches) ( 12 inches) (inches) ( 12 inches) YES 39.6 YES NO 27.6 YES NO 16.8 YES NO 13.2 YES NO 13.2 YES NO 14.4 YES NO 9.6 NO NO 13.2 YES NO 13.2 YES NO 14.4 YES NO 13.2 YES NO 13.5 YES NO 13.2 YES NO 13.2 YES NO 13.2 YES 4.5 Entrance Pool and Jump Pool Depths The water depth at the fish ladder entrance and in the pools was estimated using the average water depth measured during both low and high flow conditions. The average water depth was used because the bottom of the fish ladder pools is not flat. Depending on the pool the bottom was composed of a mix of sand and gravel. The average water depth in each pool is compared to the OAR requirements in Table 6. 34

44 Table 6 Average Pool Depths Weir Number Measured Depth (ft) Low Flow Meets OAR Requirement ( 2 ft) Measured Depth (ft) High Flow Meets OAR Requirement ( 2 ft) Riverine Pool 3.6 NA 5.5 NA YES 3.8 YES YES 4.8 YES YES 5.7 YES YES 5.6 YES YES 5.2 YES YES 6.3 YES YES 3.7 YES YES 4.3 YES YES 4.8 YES YES 3.5 YES YES 4.2 YES YES 5.1 YES YES 5.5 YES YES 5.9 YES YES 5.5 YES 4.6 Energy Dissipation The Energy Dissipation Factor (EDF) is a measure of turbulence associated with energy dissipation in each pool. Equation 3 was used to determine if the EDF meets OAR requirement of an EDF less than or equal to 4 pounds of force per square foot-second. The energy head used to calculate the EDF was assumed to equal the jump height as defined in the OAR for the weir upstream of the pool. For Pool 15 the energy head was assumed to be the difference between the water level in the reservoir and Pool 15. The estimated pool volumes and results of the EDF calculations are shown in Table 7. 35

45 Table 7 Energy Dissipation Factor Low Flow High Flow Estimated Pool Volume (ft 3) Energy Dissipation Factor (EDF) (lb F / ft 2 -s) Meets OAR Requirement (EDF<=4) Estimated Pool Volume (ft 3) Energy Dissipation Factor (EDF) (lb F / ft 2 -s) YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES Pool Number Meets OAR Requirement (EDF<=4) 4.7 Fish Ladder Exit Flow Rating Curve The flow in the upper fish ladder is a function of the difference between the reservoir elevation and the elevation of Pool 15. During the high flow evaluation, Alden measured the water level in the reservoir and Pool 15 of the fish ladder to determine the total head loss across the fish ladder exit. Using this head loss (0.9 ft) and the flow from the Weir 15 rating curve, a rating curve for the fish ladder exit was developed (Figure 9). This rating curve is based on only a single data point and assumes that only one exit orifice is open and there is no blockage of the orifice. The accuracy of the rating curve can be improved with further data. PacifiCorp should consider regularly inspecting the orifices, removal of sediment and debris within the fish ladder exit and monitoring the water level in Pool 15. With the exit maintained in a clean condition and additional water level data from the reservoir and Pool 15, a more accurate rating curve can be derived for predicting flow through the upper fish ladder. 36

46 Reservoir Elevation (ft) Fishway Exit Flow (cfs) Figure 9 Fish Ladder Exit Rating Curve 4.8 Physical Inspection As part of the high flow evaluation Alden also conducted a physical inspection of the fish ladder and fish screen. Overall the fish ladder was in good condition. There were however several issues with Weirs 14 and 15. Weir 14 was tilted slightly downstream, indicating that the weir or the fish ladder has shifted. The concrete also showed signs of deterioration. Weir 15 has a small section of concrete missing. Weir 14 and 15 are show in Photo

47 Weir 15 missing concrete at edge Weir 14 tilted and eroding concrete 4.9 Fish Screen Flows Photo 20 Physical Inspection: Weirs 14 and 15 The flow in the diversion canal both upstream and downstream of the fish screen must be known to characterize flow conditions at the fish screen. During the low flow evaluation of the fish screen, PacifiCorp s downstream gage at the penstock recorded a canal flow of 51 cfs. During the initial high flow evaluation, the downstream gage measured flow ranging from 146 cfs to 148 cfs and was generally steady. The flow estimated through the screens by integrating the recorded average approach velocities was cfs, or within about 2 percent. Alden also measured velocities on a 20 point grid upstream of the screens in an attempt to determine the total screened flow plus fish return bypass pipe flow (upstream canal flow). The flow measured using this technique was cfs, which is less than the combination of the screened flow of cfs and the estimated 13.3 cfs bypass pipe flow by about 5 percent. It is assumed that the measurement uncertainty in the water surface elevation combined with the effect of eddies near the sides of the concrete channel on the velocity measurements affected the accuracy of the flow measured at the 20-point velocity grid. During the post-maintenance high flow evaluation, the downstream gauge recorded an average flow of 119 cfs. 38

48 4.10 Fish Screen Sweeping Velocity The sweeping velocity (V s ), is the component of the velocity vector parallel to the screen surface and should be greater than the approach velocity (NMFS, 1995 & NMFS, 2011). The sweeping velocity measured at each station during the low and high flow conditions (pre- and postmaintenance) are shown in Table 8, Table 9, and Table 10, respectively. During the low flow conditions, the average sweeping velocity was 1.06 ft/s. Under the pre-maintenance high flow conditions, the average sweeping velocity was 3.16 ft/s approximately three times higher than during the low flow conditions. The increase in sweeping velocities is proportional to the increase in screened flow between the two conditions. The average sweeping velocity recorded during the post-maintenance, high-flow evaluation was 2.35 ft/s, due to the approximate 30 cfs reduction in the canal flow. Sweeping flows along the left-hand-side of the screen are greater than on the right side as a result of the influence of the upstream bend in the canal. In addition, eddies are created by the transition from the trapezoidal to rectangular canal cross-section which contribute to the nonuniformity in flow. Table 8 Pre-Maintenance Sweeping Velocity Measurements (ft/s) - Low Flow Conditions Transect Location on Transect No. Left Mid-Left Mid-Channel Mid-Right Right

49 Table 9 Pre-Maintenance Sweeping Velocity Measurements (ft/s) - High Flow Conditions Transect Location on Transect No. Left Mid-Left Mid-Channel Mid-Right Right Table 10 Post-Maintenance Sweeping Velocity Measurements (ft/s) - High Flow Conditions Transect Location on Transect No. Left Mid-Left Mid-Channel Mid-Right Right Fish Screen Approach Velocity Approach velocity, V a, is the component of the velocity vector normal to the screen face. It is customary, and required by the National Marine Fisheries Service (NMFS), to measure the approach velocity as close to the screen as instrumentation constraints will allow (NMFS, 2011). The approach velocity criterion was set for the design as 0.80 ft/s (ODFW, 1994; Taylor, S., 1995; &PacifiCorp, 1999), based on passing only salmonid fingerlings, and should not vary more than ± 10% across the screen face (NMFS, 1995 & NMFS, 2011).During the two evaluations, the distance of the measurement volume from the screen face varied. The low flow evaluation measurements were recorded approximately 5-inches from the screen face. The high flow evaluation measurements were recorded 1-inch from the screen face. The approach velocities are presented in Table 11, Table 12, and Table

50 The average measured low-flow approach velocity was 0.05 ft/s. This velocity is lower than expected due to the distance measurements were collected from the screen face. Based on the bypass canal flow of 51 cfs and the screen area of sq. ft., the average approach velocity component is estimated to have been approximately 0.26 ft/s, which is lower than the criterion. The average measured high flow approach velocity component was 0.71 ft/s for both pre- and post-maintenance evaluations. Based on the two average downstream canal flow measurements of 147 cfs and 119 cfs, the estimated average approach velocity component was 0.76 ft/s and 0.62 ft/s in the pre- and post-maintenance conditions, respectively. Individually, the measured approach velocities vary widely from their average, with all of the bold font values in Table 12 being more than 10 percent above the average. Table 11 Pre-Maintenance Approach Velocity Measurements (ft/s) - Low Flow Conditions Transect Location on Transect No. Left Mid-Left Mid-Channel Mid-Right Right Table 12 Pre-Maintenance Approach Velocity Measurements (ft/s) - High Flow Conditions Transect Location on Transect No. Left Mid-Left Mid-Channel Mid-Right Right

51 Table 13 Post-Maintenance Approach Velocity Measurements (ft/s) - High Flow Conditions Transect Location on Transect No. Left Mid-Left Mid-Channel Mid-Right Right Installing new baffles behind the screen had the effect of reducing the variation of approach velocities from the mean. The pre-maintenance velocities varied by 62% from the measured average, while the post-maintenance velocities varied by 34% from the measured average. The location of high approach velocities has also shifted from the downstream end in shallow water to the upstream end in deeper water, where fish are less likely to encounter the screen Ratio of Sweeping to Approach Velocity The ratio of sweeping velocity to approach velocity is important in evaluating the effectiveness of the fish screen. The higher the ratio, the more likely fish are to swim to the bypass entrance. The requirement for this ratio is that the sweeping velocity is greater than the approach velocity (the ratio must be 1.0 or higher per the NMFS criterion). During the low flow conditions, the average sweeping velocity (1.06 ft/s) and the calculated average approach velocity (0.27 ft/s) results in a ratio of Table 14 presents this ratio for the measured pre-maintenance high flow conditions, where ratios varied by 77% from the average, and fell below 1.0 in one location at the end of the screen with a ratio of Table 15 presents this ratio for the measured post-maintenance high flow conditions, where ratios varied by 36% from the average, and fell below 1.0 in one location, with a ratio of The single point which did not meet the criteria shifted from shallow to deeper water, where fish are less likely to encounter the screen. 42

52 Table 14 Pre-Maintenance Ratio of Sweeping to Approach Velocity - High Flow Conditions Transect Location on Transect No. Left Mid-Left Mid-Channel Mid-Right Right Table 15 Post-Maintenance Ratio of Sweeping to Approach Velocity - High Flow Conditions Transect Location on Transect No. Left Mid-Left Mid-Channel Mid-Right Right Physical Conditions of the Fish Screen Structurally the fish screen appears to be in good condition. The concrete is not deteriorated. During the June 2015 maintenance activities, the screens were cleaned and removed, new baffles were installed, and the rubber seals were inspected and replaced as necessary. Photo 21 shows the installation of the first fish screen with newly installed baffles. Prior to the maintenance activities, debris loading on the screen was heaviest toward the downstream end of the screen where the approach velocities were highest. As a result of the newly installed baffles, debris is somewhat more uniform, but has a tendency to collect at the upstream end, where approach velocities are now highest. Heavy debris was observed remaining fixed to the screen face during several cleaning cycles; debris often needs to be removed from the screen face manually with a scraper. Adjusting the cleaning screen position to a horizontal position, may increase the effectiveness of the sweeping flow to remove attached debris. 43

53 Photo 21 Fish Screen Assembly During June, 2015 Maintenance Activities 44

54 5.0 Summary, Conclusions, and Recommendations 5.1 Summary and Conclusions The objectives identified in Study Plan Section 2.0 and Section 1.3 of this Updated Study Report were achieved according to plan. The physical and hydraulic parameters identified in the Study Plan were measured according to the Plan, with the exception of the timing of high flow measurements. Initial high flow measurements were completed in January 2015 instead of May or June 2014 as stated in the Study Plan. Follow up measurements of the post-maintenance condition were conducted in February of Target exceedance flows were present at the time of the measurements, and therefore, the impact of the variance in schedule was negligible to the methods and results. Biological testing of upstream and downstream passage facilities occurred in the second study season according to the requirements of the Study Plan and is presented in Volume II of the Fish Passage Facilities Updated Study Report. No modifications to the approved Study Plan are proposed at this time Fish Ladder The flow in the upper fish ladder was estimated using the weir rating curves. During low flows the flow in the upper fish ladder was estimated to be 2.2 cfs. At high flows the upper fish ladder flow increased to 8.0 cfs. The bypass flow from the fish screen enters the fish ladder in Pool 6 increasing the flow in the lower fish ladder. During low flow, non-spill conditions, all of the flow in the South Fork bypassed reach below the dam passes through the fish ladder. Based on the flows in the South Fork bypassed reach, the flow in the lower fish way during low flow conditions is 14 cfs. There is flow over the dam during high flow conditions; therefore a flow of 21.3 cfs flow was estimated for the lower fish ladder based on a combination of flow from the upper fish ladder and the fish bypass. The fish ladder did not meet the OAR requirements for jump height and weir notch depth. The tables below summarize the findings of the fish ladder hydraulic studies, Table 16 for low flow and Table 17 for high flow. Red text is used to highlight where the criteria were exceeded. The jump heights in Table 16 and Table 17 represent the difference between the water levels upstream and downstream of each weir compared with OAR requirements. At low flow conditions, only Weir 2 meets the jump height requirement. In the Project s fish ladder, the velocity at the weir crests meets the OAR velocity requirements for all the weirs at both low and high flow conditions. Under high flow conditions all of the weirs except 7, 10, 12, and 13 were submerged and fish could pass them by swimming, not jumping, as the flow depths and velocities available for swimming through the weir notches meet the OAR requirements. In summary, only Weir 2 met all of the OAR passage requirements at low flow, while all weirs but 7, 10, 12, and 13 met the requirements at high flow. 45

55 Fish ladder exit velocities were calculated using the flow in the upper fish ladder and the open area of the exit orifice(s). During low flow the calculated exit velocity was 0.7 ft/s. At high flow the velocity increased to 2.0 ft/s. These velocities assume that the fish ladder exit(s) are clean with no debris or sediment buildup and are based on a single measurement. This same assumption was used to develop a rating curve for the upper fish ladder. Additional inspection of the exit(s) and further water level measurements would be required to increase confidence in both the velocity calculations and the rating curve. The minimum water depth over the fish ladder weirs required by the OAR is 12 inches when adult fish are present. The requirement when only juveniles are present is 6 inches. The juvenile requirement may be more applicable to this fish ladder because adult salmon are not present at the Project, and the species present include rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) that are closer in size to juvenile salmon. Based on a 6 inch minimum water depth all the fish ladder weirs would meet the OAR requirements during both the low and high flow conditions. Overall the fish ladder appeared to be in good physical condition. However, the concrete in Weirs 14 and 15 showed signs of deterioration, and Weir 14 had shifted. A more detailed inspection of the fish ladder is recommended. 46

56 Table 16 Summary of Fish Ladder Measurements and OAR Requirements Low Flow. (Red text is used to highlight where the criteria were exceeded) Jump Heights Notch Velocities Weir Notch Depth (Not Applicable at Jumps) Pool Depths Energy Dissipation Pool/ Weir No. Estimated Flow (cfs) Jump Height (inches) Meets OAR Requirement ( 6 inches) Velocity (ft/s) Meets OAR Requirement ( 8 ft/s) Measured Depth (inches) Meets OAR Requirement ( 12 inches) Average Measured Depth (ft) Meets OAR Requirement ( 2ft) Pool Volume (cubic ft) Energy Dissipation (EDF) Meets OAR Requirement (EDF >=4) NO 7.1 YES 16.8 YES 2.2 YES YES YES 5.6 YES 10.8 NO 4.0 YES YES NO 5.6 YES 10.8 NO 5.8 YES YES NO 5.3 YES 11.4 NO 6.0 YES YES NO 5.6 YES 10.8 NO 9.0 YES YES NO 5.3 YES 11.4 NO 6.6 YES YES NO 2.4 YES 7.2 NO 2.9 YES YES NO 2.3 YES 7.8 NO 3.5 YES YES NO 2.8 YES 6.4 NO 4.4 YES YES NO 2.3 YES 7.7 NO 2.7 YES YES NO 2.4 YES 7.2 NO 2.9 YES YES NO 2.5 YES 7.1 NO 3.6 YES YES NO 2.4 YES 7.4 NO 4.2 YES YES NO 2.6 YES 6.7 NO 4.9 YES YES NO 2.5 YES 7.1 NO 5.2 YES YES 47

57 Table 17 Summary of Fish Ladder Measurements and OAR Requirements High Flow. (Red text is used to highlight where the criteria were exceeded) Jump Heights Notch Velocities Weir Notch Depth (Not Applicable at Jumps) Pool Depths Energy Dissipation Pool/ Weir No. Estimated Flow (cfs) Jump Height (inches) Meets OAR Requirement ( 6 inches) Velocity (ft/s) Meets OAR Requirement ( 8 ft/s) Measured Depth (inches) Meets OAR Requirement ( 12 inches) Average Measured Depth (ft) Meets OAR Requirement ( 2ft) Pool Volume (cubic ft) Energy Dissipation (EDF) Meets OAR Requirement (EDF >=4) YES 4.3 YES 39.6 YES 3.8 YES YES YES 3.0 YES 27.6 YES 4.8 YES YES YES 5.1 YES 16.8 YES 5.7 YES YES SUBMERGED NA YES 13.2 YES 5.6 YES YES SUBMERGED NA YES 13.2 YES 5.2 YES YES SUBMERGED NA YES 14.4 YES 6.3 YES YES NO 6.7 YES 9.6 NO 3.7 YES YES SUBMERGED NA YES 13.2 YES 4.3 YES YES SUBMERGED NA YES 13.2 YES 4.8 YES YES NO 4.4 YES 14.4 YES 3.5 YES YES SUBMERGED NA YES 13.2 YES 4.2 YES YES NO 4.7 YES 13.5 YES 5.1 YES YES NO 4.8 YES 13.2 YES 5.5 YES YES SUBMERGED NA YES 13.2 YES 5.9 YES YES SUBMERGED NA YES 13.2 YES 5.5 YES YES 6 Weir submerged; notch velocity and flow depth apply for swimming passage. 48

58 5.1.2 Fish Screen The flow in the diversion channel upstream of the fish screen is controlled by two gates: the canal head gate and the backwater gate immediately downstream of the fish screen. Working in conjunction these gates can maintain a constant water level at the fish screen regardless of the flow in the canal. Hydraulic conditions at the fish screen were measured at diversion channel flows of approximately 51 cfs, 147 cfs, and 119 cfs, chronologically. The initial low and high flow measurement conditions are consistent with the flows expected during 95% (50 cfs) and 5% (150 cfs) exceedance flows in the river. Post-maintenance measurements were conducted at the highest obtainable canal flows at the time. During low flow conditions, the average sweeping velocity past the screen was 1.06 ft/s. At the pre-maintenance high flow condition the average sweeping velocity was 3.16 ft/s. The average sweeping velocity recorded during the post-maintenance, high-flow evaluation was 2.35 ft/s. The respective increases in average sweeping velocity are proportional to the increases in canal flow during the evaluations. The pre- and post-maintenance sweeping velocities were approximately three and two and a quarter times greater than the low flow sweeping velocity. The measured sweeping velocities ranged from 0.0 ft/s to 2.0 ft/s during the low flow condition, 0.7 ft/s to 4.9 ft/s during the pre-maintenance high flow condition, and 0.84 ft/s to 3.35 ft/s during the post-maintenance high flow condition. Eddies were visible along the right wall downstream of the start of the fish screen and near the left wall closer to the bypass entrance. The average screen approach velocity was calculated for both low and high flow conditions using the flow passing through the fish screen and the effective screen area. During low flow conditions the average approach velocity is estimated 7 to be 0.26 ft/s, which is below the 0.80 ± 10% criterion (ODFW, 1994; Taylor, S, 1995;PacifiCorp, 1999; NMFS, 1995; & NMFS, 2011). At pre-maintenance high flows, the average approach velocity is estimated to be 0.78 ft/s. Approach velocities were also directly measured along seven transects to quantify the flow distribution through the screens. During pre-maintenance high flow measurements approach velocities varied by 62% from the measured average of 0.71 ft/s 8, and higher velocities were observed near the downstream end of the screen, where the approach velocity criterion was exceeded. Following installation of the redesigned baffles, the variation in approach velocities has been reduced to 34%. The location of high approach velocities has also shifted from the downstream end in shallow water to the upstream end in deeper water, where fish are less likely to encounter the screen. 7 The estimated approach velocity is calculated from Equation 3, where V average = Q/A. 8 The difference between the estimated average and measured average is a result of flow variation across the screen. 51

59 5.2 Recommendations Fish Ladder The fish ladder does not meet OAR requirements for jump height and weir notch depth at the identified weirs (Tables 13 and 14). PacifiCorp and resource agency representatives should consider alternative standards such as a reduced weir notch depth of greater than or equal to 6- inches, based on the actual hydraulic conditions and species present at the Project. Results of biological evaluations of the fish ladder, conducted during the second study season (May 2015 May 2016), include observations of fish as small as 110 mm successfully ascending the ladder during the peak activity period in June and July (Meridian Environmenal, Inc., 2015). PacifiCorp may consider repairs to the degraded concrete on Weirs 14 and 15. A thorough inspection of Weir 14 is also warranted because the walls of the weir have shifted. If the weir cannot be moved back into position it should be replaced. PacifiCorp should develop a standard maintenance plan including regularly scheduled inspections and methods to remove sticks and other debris in the fish ladder. The fish ladder exit(s) should also be inspected and cleaned. A water level sensor could be used to monitor Pool 15. This sensor would allow the flow in the upper fish ladder to be monitored and a rating curve to be developed based on the reservoir stage Fish Screen PacifiCorp will informally evaluate if changing the fish screen angle during cleaning improves the efficiency and reduces the need for supplemental manual cleaning. Structurally the fish screen, support structure and rubber seals appear to be in good shape and do not need to be repaired or replaced. 50

60 6.0 References FERC. (2014). Study Plan Determination for the Prospect No. 3 Hydroelectric Project Meridian Environmenal, Inc. (2015). Fish Passage Facilities Study Report: Biological Testing. Portland, OR: PacifiCorp. MWH. (1997). Letter date April 25, 1997 regarding Prospect No. 3 Diversion Dam Fish Screen Project Hydraulic Measurements. National Marine Fisheries Service. (1995). Screen Criteria. NMFS, Northwest Region, Portland Oregon. National Marine Fisheries Service. (2011). Anadromous Salmonid Passage Facility Design. NMFS, Northwest Region, Portland Oregon. ODFW. (1994). Letter dated September 7, 1994 regarding Fish Passage Criteria and Design Selection for Prospect No. 3 Hydroelectric Project. ODFW. (2015) Oregon Administrative Rules, Division 412, Fish Passage. PacifiCorp. (1999) Letter date July 30, 1999 regarding Prospect No. 3 (FERC No ) Fish Monitoring Plan, update. PacifiCorp. (2014). Prospect No. 3 Hydroelectric Project, FERC Project No. P-2337, Revised Study Plans Fish Passage Facilities, April Taylor, S. (1995). Notes from Meeting with PacifiCorp, ODFW, and USFWS on Regarding Prospect 3 Fish Passage Improvement. Portland: PacifiCorp. 51

61 Prospect No. 3 Hydroelectric Project FERC Project No. P-2337 Updated Study Report: Fish Passage Facilities May 2016 Volume II: Biological Evaluation Prepared by: Meridian Environmental, Inc Westlake Ave. N. Seattle, WA 98109

62 Prospect No. 3 Hydroelectric Project FERC Project No. P-2337 Updated Study Report Fish Passage Facilities: Biological Evaluation Prepared for: PacifiCorp Hydro Resources 925 South Grape Street Medford, OR Prepared by: Meridian Environmental, Inc Westlake Ave. N. Seattle, WA October 2015

63 Table of Contents 1.0 INTRODUCTION Background Study Objectives METHODS Upstream Fish Passage Test Downstream Fish Passage Safety and Effectiveness Test Downstream Fish Passage Time Test RESULTS Upstream Fish Passage Test Test Fish Attributes Upstream-Origin Test Fish Downstream-Origin Test Fish Downstream Fish Passage Safety and Effectiveness Test Downstream Fish Passage Time Test DISCUSSION CONCLUSIONS REFERENCES List of Tables Table 1. Upstream fish passage test fish size class Table 2. Summary of successful upstream fish passage detections Table 3. Summary of downstream fish passage safety and effectiveness test Table 4. Downstream travel time test fish size class Table 5. Downstream travel time statistics List of Figures Figure 1. Location of Prospect No. 3 Hydroelectric Project Figure 2. Fish passage facility features during high flow in January 2015 (Alden 2015) Figure 3. PIT-tag antennas Figure 4. Screen bypass fish collection device (flume and live box) Figure 5. Largest upstream passage test fish (215 mm fork length, tag code 408, captured downstream of the dam via angling) Fish Passage Facilities Study Report: Biological Evaluation October 2015 Page i

64 1.0 INTRODUCTION PacifiCorp owns and operates the 7.2 megawatt (MW) Prospect No. 3 Hydroelectric Project (Project; FERC No. P-2337) located at river mile (RM) 10.5 on the South Fork Rogue River (South Fork) in Jackson County, Oregon (Figure 1). The Project is operated in run-of-river mode diverting up to 150 cubic feet per second (cfs) from the South Fork into the Prospect No. 3 powerhouse and Middle Fork canal. The Project has both upstream and downstream fish passage facilities (i.e., a fish ladder and fish screen with return pipe) and the current license stipulates that PacifiCorp must provide a minimum flow of 10 cfs to the South Fork below the diversion dam. The Project s existing Federal Energy Regulatory Commission (FERC) license expires on December 31, PacifiCorp plans to file an application for new license for the Project, and initiated FERC s Integrated Licensing Process (ILP) on July 1, As a component of the ILP, FERC requires applicants to develop and file relevant resource management study plans to ensure adequate resource protections. Because the Project s existing fish passage facilities had not been evaluated since 1999, PacifiCorp proposed to implement an updated physical and biological evaluation of the effectiveness of the Project s fish ladder, fish screen, and bypass system. Figure 1. Location of Prospect No. 3 Hydroelectric Project. Fish Passage Facilities Study Report: Biological Evaluation Page 1 October 2015

65 PacifiCorp s FERC-approved Fish Passage Facilities Revised Study Plan (Study Plan) contains two primary objectives (PacifiCorp 2014): 1) Determine if key physical parameters of the Project fish passage facilities are in compliance with Oregon fish passage criteria; and 2) Determine if Project fish passage facilities are biologically functional (PacifiCorp 2014). A physical assessment of the Project s fish passage facilities was previously conducted and summarized in a stand-alone study report (Alden 2015). Results showed that the fish ladder does not meet several Oregon fish passage physical criteria, including jump height and weir notch depth at low flow. The fish screen did not meet current hydraulic criteria of less than 0.4 feet per second (fps) approach velocity at low flow (90 cfs), but the screen did meet the design criteria of less than 0.8 fps approach velocity, which was approved by Oregon Department of Fish and Wildlife (ODFW) prior to construction in 1996 (ODFW 1994, Taylor 1995). The purpose of this report is to summarize biological testing of the fish ladder, fish screen, and fish bypass return pipe conducted under low flow conditions during the adult trout upstream migration period as specified in the Study Plan. 1.1 Background The Project includes a 172-foot-long, 24-foot-high concrete diversion dam with a 98-foot-long un-gated ogee spillway, and contains both upstream and downstream fish passage facilities. The upstream fish passage facility at the diversion dam consists of an 86-foot-long, 15-pool concrete pool-and-weir type fish ladder (Figure 2). This ladder was originally constructed in 1931 and has been modified twice, once in 1973 and again in The downstream fish passage facility (fish screen and return pipe) was constructed in 1996 and consists of a 0.25-inch wedge-wire, inclined plane fish screen located within the Project bypass canal. Baffles were installed after the initial 1998 hydraulic assessment to create a more uniform flow through the screen. PacifiCorp installed new screen baffles in May 2015, prior to initiation of the biological testing. Fish moving down the bypass canal and past the fish screen are directed to an 18-inch diameter bypass pipe that transports them to Pool 6 of the fish ladder (Figure 2). This flow is also used to increase the attraction flow to the fish ladder. As summarized in PacifiCorp (2014), the fish ladder was evaluated for fish use and passage efficiency during previous relicensing efforts (Pacific Power and Light Company 1986). PacifiCorp conducted a weekly trapping effort in the fish ladder between April and October Biologists observed rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) migrating upstream through the fish ladder, although only rainbow trout were captured during the evaluation. Upstream migrants were first captured in late April, and the peak use of the fish ladder occurred in late May and early June. The upstream migration continued through early July. No upstream migrants were captured after early July. Forty-five rainbow trout were captured during the study period. The majority of captured fish required more than 24 hours to exit the fish ladder. Fish Passage Facilities Study Report: Biological Evaluation Page 2 October 2015

66 Figure 2. Fish passage facility features during high flow in January 2015 (Alden 2015). Fish Passage Facilities Study Report: Biological Evaluation Page 3 October 2015

67 PacifiCorp evaluated the effectiveness of the Project s downstream fish passage facilities in 1999 (PacifiCorp 2000). Two study trials were conducted in which 305 hatchery rainbow trout from two size classes (60 to 100 mm and 100 to 150 mm) were introduced into the canal approximately 100 feet upstream of the fish screen. A fish collection device was installed within the fish bypass system and used to sample the entire fish bypass pipe flow during the evaluation. All successfully bypassed fish captured in the collection device were examined for injury or mortality, and were held in the live box for 24 hours to assess delayed mortality. The study results showed that 87 percent of the fish that encountered the screen were bypassed, and the remaining 13 percent were entrained through a gap in a seal at one of the screen edges. The seal was subsequently improved to prevent future entrainment, as recommended by the study. No immediate or delayed mortality was observed among the recovered fish. Six of the recovered fish exhibited superficial injuries. However, it could not be determined whether the injuries were from the fish bypass facilities or if injury occurred in the hatchery or during transport prior to release. 1.2 Study Objectives The objectives of the fish passage facilities revised study plan (biological testing) include the following: 1. Determine upstream passage success rate and travel time of PIT-tagged 1 naturally produced trout introduced into Pool 1 of the fish ladder. 2. Determine downstream passage effectiveness of hatchery trout released into the bypass canal upstream of the fish screen. 3. Determine injury of hatchery trout successfully screened into the fish bypass system. 4. Determine travel time through the fish bypass system (time from introduction into the bypass pipe to exiting the downstream end of the fish ladder) of PIT-tagged hatchery trout. 2.0 METHODS 2.1 Upstream Fish Passage Test Upstream fish migration success rate and travel time were evaluated using a PIT-tag and track method. In accordance with the Study Plan, thirty naturally produced rainbow trout were captured downstream of the fish ladder using electrofishing and angling. We also captured five naturally produced rainbow trout from upstream of the diversion dam in the impoundment via angling. These fish were then abdominally tagged with 23 mm half duplex PIT-tags (Oregon RFID) and introduced into Pool 1 of the fish ladder between June 11 and June 13, The tracking system consisted of four PIT-tag antennas, each with continuous detection and recording capabilities, to monitor passage of PIT-tagged trout introduced into Pool 1 of the fish ladder. The antennas were installed at the fish ladder entrance (Pool 1, Antenna A1), at each corner of the 90 degree turn (Pool 6, Antenna A2, and Pool 8, Antenna A3), and at the fish ladder exit (Pool 15, Antenna A4). 1 Passive integrated transponder tags. Fish Passage Facilities Study Report: Biological Evaluation Page 4 October 2015

68 All antennas were installed in the locations specified in the Study Plan except the most upstream antenna. The Study Plan specified the most upstream antenna should be placed at the submerged orifice of the fish ladder exit. During field installation, this was not a practical antenna installation location due to depth, lack of stable substrate and anchoring options. Instead, the fish ladder exit antenna was installed on the upstream side of the final vertical slot jump into Pool 15 (most upstream fish ladder pool). There were no additional jumps or passage impediments between this antenna and the fish ladder exit orifice. In addition, the distance between the last jump location and the exit orifice is approximately ten feet. Water velocity between the exit orifice and Antenna Also appeared to be low during low-flow installation conditions (Figure 3). For the purpose of this study, we assume that fish passing Antenna A4 had navigated all potential obstacles within the fish ladder to successfully pass upstream. All antennas were vertically oriented pass-through type, installed immediately on the upstream side of each vertical pool entrance slot (Figure 3). Each antenna surrounded the wetted portion of the pool entrance slot and was flush to the upstream side of each concrete wing wall. The antennas were continuously monitored using an Oregon RFID four-antenna multiplex receiver/ logger operated via on-site AC power. The detection/logger system was continuously operated from the time test fish were initially introduced into Pool 1 of the fish ladder on June 11 to July 31, 2015, when the PIT-tag detection system was removed. Testing with a dummy tag prior to introduction of tagged fish indicated complete functionality with no apparent gaps in each detection zone. The Study Plan required conducting the upstream passage test until the PIT-tag detection data indicated that all fish had either passed through the fishway exit or entrance. Due to the potential for errors in detection (see discussion of tag collision in Section 4) and an indefinite conclusion to the study term, PacifiCorp determined that the PIT-tag detection system would run through July to ensure that the end of the migration period identified by Pacific Power and Light (1986) was encompassed by this study. Fish Passage Facilities Study Report: Biological Evaluation Page 5 October 2015

69 Figure 3. PIT-tag antennas. Fish Passage Facilities Study Report: Biological Evaluation Page 6 October 2015

70 2.2 Downstream Fish Passage Safety and Effectiveness Test In accordance with the Study Plan, two trial releases of hatchery-reared trout were made within the bypass canal upstream of the fish screen on July 1, The first release included 150 fish approximately 60 to 100 mm in fork length. The second release included 150 fish approximately 100 to 150 mm in fork length. All fish were rainbow trout/steelhead obtained from ODFW s Cole Rivers Hatchery in Trail, Oregon. Test fish were collected in the early morning and transported to the Project site in a 150-quart cooler with internal baffles, ice, and dual aerators. Fish selected for each release were then dip-netted from the cooler, counted, placed into fivegallon buckets according to size class, and released approximately twenty feet upstream of the upper end of the fish screen on both sides of the bypass canal. Only fish in good condition and without apparent injuries (after transport to the project site) were used to conduct the test. Bypassed fish were then recaptured in the same fish collection device used in the 1999 evaluation (Figure 4). The fish collection device was operated for approximately 4 hours immediately following the fish release. At that point, the bypass canal was de-watered and the remaining test fish within the canal were recovered via electrofishing. All re-captured fish were examined for injury and measured to fork length. The screen was also checked for gaps and impinged fish during the bypass canal dewatering. In accordance with the Study Plan, it was assumed that any fish not collected in the fish collection device live box or in the canal following the trial were entrained through the fish screen. In accordance with the Study Plan, the effectiveness of the fish screen was determined for each trial as: Effectiveness = total fish bypassed / (total fish bypassed + total assumed entrained) Figure 4. Screen bypass fish collection device (flume and live box). 2.3 Downstream Fish Passage Time Test In accordance with the Study Plan, thirty hatchery rainbow trout/steelhead ranging from approximately 65 to 150 mm in length were obtained from the Cole Rivers Hatchery. These fish were then PIT-tagged, and released immediately upstream of the bypass pipe entrance. The elapsed time required for fish to pass the two PIT-tag antennas (antennas A1 and A2) downstream of the bypass pipe exit into the fish ladder was determined via the PIT-tag detection Fish Passage Facilities Study Report: Biological Evaluation Page 7 October 2015

71 system described in Section 2.1. The downstream passage trial occurred on June 12, 2015 during a low flow period when a high proportion of flow was being diverted into the Project. 3.0 RESULTS 3.1 Upstream Fish Passage Test Test Fish Attributes Thirty-five naturally-produced rainbow trout were captured, PIT-tagged and released into Pool 1 of the fish ladder during the second week in June. All test fish were greater than or equal to 65 mm in fork length. Though a few brook trout were captured during the collection effort, they were not used for the upstream migration test as they are a non-native species. Fish tag and release dates included: June 11, 2015 (30 fish originating downstream of the fish ladder), June 12, 2015 (1 fish originating upstream of the fish ladder), and June 13, 2015 (4 fish originating upstream of the fish ladder). On June 11, 2015, the 30 fish originating downstream of the fish ladder were released into Pool 1 in groups of 10 in accordance with the Study Plan. The smallest fish was 89 mm fork length and the largest was 215 mm fork length (Figure 5). Most fish ranged between 100 and 149 mm fork length (Table 1). Figure 5. Largest upstream passage test fish (215 mm fork length, tag code 408, captured downstream of the dam via angling). Table 1. Upstream fish passage test fish size class. Size Class (Fork Length) Number Tagged mm mm mm 7 >200 mm 2 Due to distinct behavioral differences, upstream-origin (rainbow trout captured upstream of the diversion dam) and downstream-origin (rainbow trout captured downstream of the diversion dam) test fish results are summarized separately. For the purpose of this analysis, Antenna A1 is Fish Passage Facilities Study Report: Biological Evaluation Page 8 October 2015