YSF Action 6 - Fish Ladder Over Existing Englebright Dam … · 2013-03-21 · Fish Passage Infrastructure Report SECTION 7.0 ACTION 6 - FISH LADDER OVER EXISTING ENGLEBRIGHT DAM

Section7.0 Action6–FishLadderOverExistingEnglebrightDam

YubaSalmonForumTechnicalWorkGroup Page7‐1 March2013FishPassageInfrastructureReport

SECTION 7.0 ACTION 6 - FISH LADDER OVER EXISTING ENGLEBRIGHT DAM

This section describes the construction of a fish ladder over Englebright Dam, and passage to the Middle and South Yuba rivers, and to the North Yuba River downstream from New Bullards Bar Dam. This action would allow for passage of anadromous fish from the mouth of the Yuba River to the base of New Bullards Bar Dam on the North Yuba River, and to access approximately 36 miles of the Middle Yuba River, and 35 miles of the South Yuba River. Please refer to the habitat reports produced by the Yuba Salmon Forum (YSF) Technical Working Group (TWG) for a description of the spawning, egg incubation, juvenile rearing and out-migration habitat that would be made available by this Action. Fish that ascend the ladder into Englebright Reservoir would be subjected to additional passage barriers before reaching the uppermost limit of the available habitat, and therefore this action addresses these additional barriers similarly to Action 4 (Section 5) and Action 5 (Section 6). Fish behavior would play a larger role in this action than in any of the other actions because of the length of the ladder and the presence of up to 9 miles of reservoir to traverse. This action has the highest degree of scientific uncertainty of any of the actions evaluated in this report. This report does not address these fish behavior issues and is solely focused on the physical actions necessary to provide an opportunity for fish passage within the watershed.

7.1 ACTION DESCRIPTION AND ACTION-SPECIFIC DESIGN ASSUMPTIONS

7.1.1 Action Description

This action would involve the construction of a fish ladder over the existing Englebright Dam so spring-run Chinook salmon and steelhead could migrate above Englebright Reservoir and into the Middle, South, and lower North Yuba Rivers. The ladder would likely be constructed along the northern side of the Yuba River, with its entrance near the existing Narrows 2 Powerhouse. The ladder would include a research station at its lower end with the capability for collecting and tagging of adult spring-run Chinook salmon and steelhead. The normal water surface elevation immediately downstream of Englebright Dam is approximately 287 ft and the existing dam crest elevation is 527 ft, for a height difference of approximately 240 feet. According to research and anecdotal information, no ladder has been successfully implemented over a dam of this height. Challenges associated with the dam height would include water temperature management, ability of the structure to withstand extremely high flood flows and associated debris loading, and the extreme length of the ladder.

Some analysis will be needed to identify means of addressing water temperature differentials between the upper end of the ladder (assuming water temperatures have been maintained for its full length,) and the epilimnion of Englebright Reservoir. Also, there could be additional water temperature differential challenges between Englebright Reservoir, the South Yuba River at its confluence with Englebright Reservoir, and the Yuba River above the New Colgate Powerhouse. For example, there could be a water temperature differential of more than 10 degrees Fahrenheit between Englebright Reservoir and the lower end of the South Yuba River. It is unlikely fish would voluntarily leave the much colder Englebright Reservoir in favor of the relatively warm water temperatures of the South Yuba River.

With the availability of the lower North, South and Middle Yuba rivers to anadromous salmonids, some form of reoperation of YCWA’s Yuba River Development Project, NID’s Yuba-



Bear Project and PG&E’s Drum-Spaulding Project would also likely be required to ensure suitable flows and temperatures in potential habitat areas. Each of these actions would result in either a reduction in water supply to customers or in the value of hydroelectric generation from the respective projects, or both.

This action includes juvenile salmon and steelhead collection and adult downstream migrating steelhead collection within Englebright Dam and the transport of these fish to the lower Yuba River. For this report, use of the two existing powerhouse intakes has been developed. A floating surface collector (FSC) could be evaluated in the future, however there are technical issues with the FSC at this location and it was considered less feasible than the use of the existing intakes for collection purposes.

7.1.2 Action-Specific Design Assumptions

Below is a list of general assumptions for the assessment of the construction of a fish ladder over the existing Englebright Dam:

All elevations presented in the document are on the National Geodetic Vertical Datum of 1929 (NGVD29), unless otherwise noted.

Habitat currently inaccessible upstream of Englebright Dam would actually be voluntarily used by anadromous salmonids in numbers that would support reintroduction goals.

Passage improvement is required at Daguerre Point Dam to allow optimal passage.

Recreation impacts are mitigable and would not impact construction schedule

Any existing facilities and utilities can be relocated and would not impact construction schedule

The existing barrier at Our House Dam would require some form of upstream and downstream passage, likely a fish ladder and a screen on the Lohman Ridge Tunnel diversion.

Tagging and other monitoring of fish using the ladder would be desirable to monitor success.

With the availability of the South and Middle Yuba rivers to anadromous salmonids, some form of reoperation of the Nevada Irrigation District’s (NID) Yuba-Bear Project and Pacific Gas and Electric Company’s (PG&E) Drum-Spaulding Project would also be required to ensure suitable flows and temperatures in potential habitat areas.

Similarly, with changes to Englebright Reservoir’s availability as a re-regulating afterbay, Yuba County Water Agency’s (YCWA) Yuba River Development Project (YRDP) would require changes in operations to ensure well-regulated flows downstream of the New Colgate Powerhouse. Each of these actions would result in either a reduction in water supply to customers or in the value of hydroelectric generation from the respective projects, or both.

7.2 ELEMENTS OF THE ACTION

To construct Action 6 – Fish Ladder Over Existing Englebright Dam, a number of project elements would be required. This section describes those project elements, their justification, the



approach to their design, and any assumptions specific to each element. The following is a list of the key elements of Action 6. The elements listed are not intended to represent the final selection for each project element, but rather feasible options to allow a realistic appraisal of the scope and cost of the overall action. Figure 7-1 shows an overview of the action and indicates the locations of proposed new facilities and modifications to existing facilities.

1. Construction of a fish ladder at Englebright Dam

2. Construction of a fish screen and juvenile return at Narrows 1 Powerhouse Intake

3. Construction of a fish screen and juvenile return at Narrows 2 Powerhouse Intake

4. Construction of a juvenile release facility on the Lower Yuba River

5. Construction of a tailrace barrier at New Colgate Powerhouse

6. Construction of a fish ladder at Our House Dam

7. Construction of a Fish Screen and Juvenile Return on the Lohman Ridge Tunnel Diversion at Our House Dam

8. Improvement of North Yuba River Habitat Below New Bullards Bar Dam*

9. Improvement of New Bullards Bar Reservoir Low-Level Release Outlet reliability

10. Reoperation of NID’s Yuba-Bear project*

11. Reoperation of PG&E’s Drum-Spaulding project*

12. Reoperation of YCWA’s YRDP*

13. Restoration of water supply to NID and PCWA customers*

14. Restoration of hydropower generation value to NID and PG&E (Yuba-Bear and Drum-Spaulding Complexes)*

15. Restoration of hydropower generation value of Narrows 1, 2, and New Colgate Facilities.

16. Improved passage at Daguerre Point Dam

17. Monitoring and Evaluation

* Designated elements have been identified and described but preliminary design and cost considerations will be developed by others and are not addressed in this document.



Figure 7-1. Action 6 Overview Map

7.2.1 Construction of a Fish Ladder at Englebright Dam (Element 1)

Description: There is a desire to restore anadromous salmonids, particularly spring-run Chinook salmon and steelhead, to the Yuba River watershed above Englebright Dam. A vertical slot -type fish ladder design has been developed to allow passage over the dam (refer to Plate 30 and additional details on Plates 28 and 29). The ladder would be accompanied by a biological research station at its downstream end, where examination, tagging, and sorting of adult salmon and steelhead could take place. This biological research station would include a number of ancillary structures, such as holding pens, in addition to the primary research facility. The ladder itself would be constructed on the northern bank of the Yuba River with its lower entrance adjacent to the Narrows 2 Powerhouse. Water would need to be supplied from the Narrows 2 Powerhouse to provide attraction flow at the downstream end of the ladder. The ladder itself would be at least 2,470 ft. long, with pools meeting NMFS design criteria for length, width, and height. Due to the extreme length of the ladder, there would also need to be resting pools at points along the ladder, allowing the adults to recover before continuing up the ladder. Colder water pumped from deep within Englebright Reservoir would be the primary source of flow in the upstream end of the ladder. Additional cold water from the reservoir would need to be introduced into the ladder at multiple points to ensure adequate water temperatures throughout the length of the ladder. Fish would exit the ladder via a fish weir at the upstream end and would



then slide down a chute to the reservoir. The chute would be designed to accommodate the daily varying elevations of the reservoir’s water surface over its full operable range.

Since the ladder would be anchored to the hillside downstream from the dam, the ladder and its anchoring would need to be designed to withstand a dam overtopping event of a 100-year flood event without being dislodged from its anchoring or at its interface with the dam.

Justification: Construction of a ladder at Englebright Dam would allow anadromous salmonids to move into the upper Yuba River watershed semi-volitionally- it would not be truly volitional since the ladder will require operations to maintain suitable flows and water temperatures for the anadromous salmonids. The research station at the lower end of the ladder would allow the monitoring of usage of the ladder, would allow for the tagging of adults, and would be used to ensure fall-run Chinook salmon do not pass into the upper watershed.

Design Approach: The design approach included consideration of various the components of the ladder and associated facilities, including the fish handling station and the ladder exit apparatus. The mechanism for releasing fish into Englebright Reservoir for the full range of potential reservoir surface elevations, and for a mechanism for maintaining water temperatures within the ladder at a level that would induce fish to both enter the ladder and to exit it into the reservoir were also evaluated. To the extent practical, the ladder was designed to operate with a minimum of human interaction.

Design Assumptions/Criteria: The design assumptions and criteria used in the engineering design and cost estimating efforts for this element of Action 5 are listed below. Also refer to Section 1 Introduction for additional project assumptions.

The ladder would be operated so as to pass spring-run Chinook salmon and steelhead into Englebright Reservoir.

The ladder would pass the peak run of fish over the season.

The ladder would be designed in such a manner that it could release fish to Englebright Reservoir for the full normal operable range of Englebright Reservoir water surface elevations.

The ladder would include a mechanism for managing water temperatures within the ladder within a generally accepted range.

The ladder would include provisions for tagging and biological study, through a holding and tagging facility at its lower end.

A backup generator would be used for power supply if the electrical service were lost.

The ladder would conform to NMFS and CDFG guidelines

The ladder would be designed to carry sufficient flow as to allow anadromous fish to safely move into Englebright Reservoir.

The ladder would be designed to withstand a 100 yr flood event.

All facilities will be designed to withstand a maximum Englebright Reservoir water surface elevation of 545, based on previous recorded high water elevation reported by YCWA.



340 cfs of auxiliary water supply (AWS) would be provided at the ladder’s downstream end from the Narrows 2 powerhouse. (10% of peak Narrows 2 Powerhouse flow)

A tailrace barrier would be constructed at the existing Narrows 2 Powerhouse. Design maximum outflow of 3,400 cfs. The design flow velocity at the barrier would be 1 ft/sec. The bar racks at the barrier are assumed to be approximately 13 ft. tall and 270 ft. long.

Maximum Englebright Reservoir WSEL = 530 ft

Minimum Englebright Reservoir WSEL = 517 ft

Approximate WSEL immediately downstream of Englebright Dam = 290 ft

Fish ladder would be a vertical slot type

Invert of Fish Ladder at Dam = 531 ft

Fish ladder design flow = 42 cfs

Fish ladder would have 3 ft of freeboard (per NMFS guidelines)

Assume 1 ft thick ladder floor slab

Water surface drop between pools = 1 ft

Vertical slot width = 1 ft

Pool dimensions = 8 ft wide x 10 ft long

Nominal fish ladder slope = 10%

The invert of the new fish ladder at downstream entrance would be elevation 284 (290 tailwater - 6ft depth).

Nominal fish ladder exit chute design slope = 10%

Design approach velocity for fish screens for temperature control system cooling water = 0.33 ft/sec

Engineering Design Development: Items relating to engineering design development and construction cost considerations for Action 6 – Element 1 are listed below:

The proposed volitional fish passage facility at Englebright Dam would include the following elements:

Vertical slot fish ladder with a pumped water supply

A false weir and exit chute arrangement at the top of the fish ladder (at top of dam)

Supplementary cooling water pumping and delivery system

Fish ladder entrance with an auxiliary water supply (AWS) system

Holding and tagging facilities

Approximate fish ladder length = [531 – (290 – 6)]/0.10 = 2470 ft (247 pools). Additional resting pools will likely be required, this will be determined in detailed design phase. Hard rock excavation will be required to construct ladder.



The fish ladder would include a false weir located at its apex at the top of dam. False weir is essentially a curved diffuser plate at the top of a 3 ft long by 2 ft wide slot in a structure located within the ladder. Fish coming up the ladder jump through the false weir flow and are carried down an exit chute that extends from the top of the dam to an elevation one foot below the design low reservoir water surface elevation. The chute is hinged at the top and supported by floating pontoons at the reservoir water surface. Water is introduced to the false weir structure from below via a 36 inch diameter pipe. Total flow through the false weir is 30 cfs, with 17 cfs directed down the fish ladder and 13 cfs directed in the opposite direction down the fish exit chute. Additional ladder water flow (30 cfs) is provided by a second 36 inch diameter pipe which enters the ladder from below, via a diffuser plate.

During the summer months, Englebright Reservoir surface water will be significantly warmer (10 to 15 degrees F) than the water released downstream via the Narrows Powerhouses. Fish are not likely to successfully travel up the proposed ladder if relatively warmer water comprises the ladder flow. Therefore cooler water from deeper in the Reservoir would be used to supply flow to the fish ladder. The water would be introduced to the ladder via a false weir arrangement.

The fish ladder will experience significant solar heat gain in the hot summer months and would warm the transmitted water over its considerable length. Therefore it will be necessary to pump additional cooling water from the reservoir and inject it at several locations along the ladder to maintain sufficiently cool water to promote fish passage.

To attract fish to the ladder, an auxiliary water supply (AWS) system would be provided. The AWS would be provided via a new structure and connection at the Narrows 2 Powerhouse draft tube and would introduce a large attraction water flow at the entrance to the ladder.

To protect the fish entering the ladder, a tailrace barrier would be included in the design of the Narrows 2 draft tube extension and would be constructed concurrently with the extension. It is assumed that the tailrace barrier would be similar to the Colgate Power house tailrace barrier described in Action 4, Element 17.

A holding and tagging facility would be provided near the fish ladder entrance. A swinging gate extending into the fish ladder would be opened to direct fish into the holding area. The holding and tagging facility would be similar to that described for use at Daguerre Point Dam in the 2010 NMFS Report. Rock anchors and/or Micropiles are expected to provide full uplift resistance for the structure. For estimating, 8-inch diameter Micropiles, 60 feet long at 8-feet spacing have been assumed.

Additional Fish Passage Design Details

Fish ladder flow and chute flow (total 60 cfs, 20 ft head) would be supplied by a pair of 180 HP pumps (duty/standby). An additional 60 cfs/180 HP pump would be provided to pump temperature adjustment water. Pumps would be mounted on the top of the dam and would draw cool water from the reservoir at approximate elevation 470. Retrievable rotating brush-cleaned cylinder fish screens would be used to protect fish from pump intake. Two manifolded 60” diameter fish screens (ISI Model T60-90) would be required. Retrieval rails extend from top of dam down to elev. 470. Water flows through the fish



screens into a manifold box and on through an 84 inch diameter pipe to the suction of the three pumps.

Upstream of false weir, the chute is formed by an articulating 2 ft. diameter pipe inside a truss box beam. The pipe is supported at an articulating pin connection at the dam and a floating dock where it enters the water. Assume 13 cfs upstream sluicing flow rate to achieve approximate 9.5 inch flow depth in half-pipe (NMFS bypass criteria). Chute descent angle will vary depending on reservoir water surface elevation but will be designed to limit maximum impact velocity at reservoir water surface to 25 ft/sec [assume 10 percent slope]. (NMFS bypass guidelines). Terminate pile supported chute at elev. 516, one ft below min WSEL. The maximum ladder water surface elevation would be elevation 537, just downstream of the false weir (assume 6 ft min water depth)

Additional cold water will be required during summer months to prevent the water in the ladder from warming and reducing acceptability to fish. It is assumed that a temperature adjustment flow of 7.5 cfs at 8 locations for a total of 60 cfs would be required. Temperature adjustment water is distributed via a 48-inch diameter manifold pipe and introduced to flow equalization structures at the fish ladder via 14” Ross energy dissipating valves. Water is introduced to fish ladder pools via diffuser boxes. Excess warm water is removed via overflow weirs at 8 locations and routed to a 48 inch diameter overflow pipe discharged near the ladder entrance.

AWS flow provided by two 72-inch diameter steel pipes connected to new concrete structure extension at Narrows 2 powerhouse draft tube exit. Concrete structure includes 2 gates to be closed to provide back pressure for pipe flow. Also includes metal superstructure to access gate operators. Pipes include 72 inch butterfly valves for isolation. Flow introduced to fish ladder via floor diffuser.

The holding and tagging facility would be a concrete structure. Three holding ponds at 50 feet long by 10 feet wide by 5 feet deep would be provided. These ponds would accommodate a maximum daily volume of up to 2,000 migrant fish.

Operation and Maintenance: The fish ladder would require year-round daily inspection by a team of two workers to assure the system is functioning properly. Minor monthly maintenance and more advanced annual maintenance would be required for the fish ladder cooling water pumps and instrumentation, holding and tagging facility equipment and instrumentation, and miscellaneous valves, gates, piping, etc.

Electrical power would be required to operate the fish ladder cooling water pumps, valves and intake fish screen cleaning system. Power would also be required for tailrace barrier trash rack operation, holding and tagging facility gates, and other miscellaneous equipment and instrumentation. Periodic inspection and exercising of the backup diesel generators would be required.

Design Items Considered But Not Included: Items considered but not included with Action 6 – Element 1 are listed below:

A deflection structure/log boom may be required upstream of the Narrows 2 draft tube extension and tailrace barrier to prevent these facilities from being impacted with debris that comes over the dam.



Providing the back pressure (assume 1 ft.) that will be required to drive the AWS could impact the efficiency of power generation

If the powerhouse is down for emergency or scheduled maintenance no attraction water would be available. Major maintenance can take up to 6 months. An additional 84” diameter pipe could be routed from the powerhouse bypass to the concrete extension to provide AWS if the powerhouse is not operational. This pipe would require 84inch diameter high pressure rated isolation valves on both sides of an 84-inch diameter pressure reducing valve.

7.2.2 Construction of a Fish Screen and Juvenile Return at Narrows 1 Powerhouse Intake (Element 2)

Description: The Narrows 1 Powerhouse intake consists of a “bird cage” intake tower with a trashrack. A design has been developed for a fish screen to keep juvenile anadromous salmonids out of the Narrows 1 Powerhouse, and a collection facility to capture, tag and otherwise study juveniles and downstream migrating adult steelhead, and subsequently load them into a truck to return them to the lower Yuba River to continue migrating downstream. Refer to Plates 31 and 32.

Justification: Both adult anadromous salmonids moving upstream and juvenile fish migrating downstream would potentially be drawn into the Narrows 1 Powerhouse intake tower, therefore a fish screen is needed to ensure they would not be drawn into the Narrows 1 intake and subsequently drawn into, and likely destroyed at, the Narrows 1 Powerhouse.

Design Approach: The fish screen design approach on the Narrows 1 Powerhouse intake was to limit effects of juvenile spring-run Chinook salmon and steelhead on Narrows 1 Powerhouse operations, and eliminate entrainment of juvenile salmon at the Narrows 1 Powerhouse intake.

Design Assumptions/Criteria: The design assumptions and criteria used in the engineering design and cost estimating efforts for this element of Action 6 are listed below. Also refer to Section 1 Introduction,” dated January 30, 2012, for additional project assumptions.

The fish screen will be designed to operate for the full Narrows 1 Powerhouse capacity of 720 cfs.

The fish screen and return will be designed in accordance with NMFS guidelines

The fish screen and return will be designed for continuous operation during a 100-year flood event.


A remote-operated/automatic trash-rack clearing mechanism will be provided.

Assumed minimum full flow operating level = 517 ft

Lowest 95 percent exceedance level during the January to June migration period is in April at 504 ft. Reduced flow through screens would be required at this water surface elevation.

Screen design flow = 720 cfs



Screen design approach velocity = 0.33 fps

Primary screens 10’w x 38’high (15’ high screen material), 16 total (8 each side)

Bypass channel is 2 ft wide expanding to a 3’ pipeline

3- 8’ x 30’ holding ponds with mechanical crowder. Ponds would have a minimum 4 ft depth and would fluctuate to the full operational range to a lake level of 530.

The Monitoring/Evaluation/Transport facility would be sized to hold 420,000 juvenile fish for sorting and transport. Provisions would be included to segregate downstream migrating adults from the juveniles.

The juvenile collection facility will include facilities to do a water-to-water transfer of juveniles into a specially-designed tanker truck.

Transport trucks (3) will include life support systems such as cooling and waste disposal to ensure the juveniles and downstream migrating adults are successfully released to the lower Yuba River. Three trucks will allow flexibility and redundancy for successful fish transport.

Penstock isolation gate(s) will be provided

A stoplog system will be provided at the upstream end of the fish screen for isolation and protection.



The proposed fish passage facility at the Narrows 1 Intake would include the following elements:

Fish screen to keep juvenile anadromous salmonids out of the Narrows 1 Powerhouse,

Fish will be routed to a collection facility to capture, tag and otherwise study juveniles,

Loading and transport facility will provide water to water safe transfer of fish from the holding area to the transport vehicles

Both adult anadromous salmonids moving upstream and juvenile fish migrating downstream would potentially be drawn into the Narrows 1 Powerhouse intake tower, therefore a fish screen is needed to ensure they would not be drawn into the Narrows 1 intake and Powerhouse.

The fish screen on the Narrows 1 Powerhouse intake would be designed to limit effects of juvenile spring-run Chinook salmon and steelhead on Narrows 1 Powerhouse operations, and to limit entrainment of juvenile salmon at the Narrows 1 Powerhouse intake.

Fish screens will be constructed on the east side of the reservoir upstream of the dam and excavated into the hillside to provide sound foundation. The screen structure would not be designed to be dewatered under full pool due to uplift. Maintenance is assumed to be



done via divers or by lowering of the reservoir. Rock anchors and/or Micropiles are expected to provide safe operating differentials. For estimating, 8-inch diameter Micropiles, 30 feet long at 8-feet spacing have been assumed.

A trashrack will be provided at the upstream end of the screen structure to manage debris to size that can be bypassed through the system. Kelt passage windows would be included in the rack design to allow movement of adults downstream to the holding area. Automated trash rakes would be provided.

Fish screens would include primary screens and secondary screens sized to remove 100 percent of the generation flow. Automated screen cleaners will be installed on all screens to regularly clean 100 percent of the required screen area.

A fish bypass system at the downstream end of the secondary screens will route fish from the screens to the Monitoring and Evaluation Facility holding ponds.

An automated penstock isolation gate would be provided at the entrance to the penstock. The gate will be a 9 ft diameter actuated slide gate.

The Monitoring and Evaluation facility would be excavated into the shoreline to a main floor elevation of 511. The structure would be exposed to the full reservoir water elevations so the walls would extend to elevation 545 to protect the facility to the 100 yr level. The structure would not be designed to be dewatered under full pool due to uplift. Rock anchors and/or Micropiles are expected to provide full uplift resistance for the structure. For estimating, 8-inch diameter Micropiles, 60 feet long at 8-feet spacing have been assumed.

The Monitoring and Evaluation facility will provide temporary holding for all captured fish from the fish screens until they can be processed and/or transported. The fish bypass pipe would discharge into a distribution channel that would automatically direct fish to the active holding pond(s). Fish would be sorted and either returned to the lake or transported downstream.

Bypass flow will be determined to ensure efficient capture and transport of fish and is expected to be 10 cfs to 40 cfs. Final screening will be provided in the distribution channel to remove flow in excess of that which is routed through the holding ponds.

Three holding ponds are provided to allow continuous holding and processing of fish. Refuge racks to allow age class separation in the holding ponds would be required.

Water flow to the Monitoring and Evaluation facility will be regulated by a series of four 25hp pumps having an installed capacity to handle the maximum flow plus a standby pump. These pumps would need to lift the water about 15 ft to allow discharge back to the lake.

Operation and Maintenance: The fish screen and collection/transport facility would require year-round daily inspection by a team of two workers to assure the system is functioning properly. Minor monthly maintenance and more advanced annual maintenance would be required for fish screen sediment removal, screen cleaning system, utility water pumps, monitoring facility water pumps, gantry hoists, trash rack rake, and other miscellaneous valves, gates, piping, and instrumentation. It is assumed that a team of two operators would be required to load and transport collected fish.



Electrical power would be required to operate the pumps and mechanical system noted above. The fish transport trucks would require regular fueling, as well as routine maintenance. Periodic inspection and exercising of the backup diesel generator would be required.


The use of a bypass pipe rather than capture and transport was considered but was rejected for several reasons:

Narrows 1 and Narrows 2 Bypass pipes would likely need to be combined to allow one pipe to be routed down the canyon, complicating operation of the facilities.

Bypass pipeline would be more than 4,000 feet long and construction would be difficult and expensive in the steep rock canyon. A road would need to be constructed for pipeline maintenance access.

Bypass pipeline routed on steep canyon walls would be susceptible to catastrophic failure from rockslides.

Accommodating expansion/contraction of the pipeline due to large ambient temperature range in the canyon, while maintaining a smooth inner pipe surface for fish safety, would be technically challenging.

7.2.3 Construction of a Fish Screen and Juvenile Collection Facility at Narrows 2 Powerhouse Intake (Element 3)

Description: The Narrows 2 Powerhouse intake consists of an intake tower with a trashrack. A design has been developed for a fish screen to keep juvenile anadromous salmonids out of the Narrows 2 Powerhouse, and a collection facility to capture, tag and otherwise study juveniles and downstream migrating adult steelhead, and subsequently load them into a truck to return them to the lower Yuba River to continue migrating downstream. Refer to Plates 33 and 34.

Justification: Both adult anadromous salmonids moving upstream and juvenile and adult fish migrating downstream would potentially be drawn into the Narrows 2 Powerhouse intake tower, therefore a fish screen is needed to ensure they would not be drawn into the Narrows 2 intake and subsequently drawn into, and likely destroyed at, the Narrows 2 Powerhouse.

Design Approach: The fish screen design approach on the Narrows 2 Powerhouse intake was to limit effects of juvenile spring-run Chinook salmon and steelhead on Narrows 2 Powerhouse operations, and eliminate entrainment of juvenile and adult salmon at the Narrows 2 Powerhouse intake.

Design Assumptions/Criteria: The design assumptions and criteria used in the engineering design and cost estimating efforts for this element of Action 6 are listed below. Also refer to Section 1 Introduction,” dated January 30, 2012, for additional project assumptions.

The screen will be designed to operate for the full Narrows 2 Powerhouse capacity of 3,400 cfs.

The fish screen and return will be designed in accordance with NMFS guidelines

The fish screen and return will be designed for continuous operating during a 100-year flood event.




A remote-operated/automatic trash-rack clearing mechanism will be provided.

Assumed minimum full flow operating level = 517 ft

Lowest 95 percent exceedance level during the January to June migration period is in April at 504 ft. Reduced flow through screens would be required at this water surface elevation.

Screen design flow = 3,400 cfs

Screen design approach velocity = 0.33 fps

Primary screens 9’w x 20’high (20’ high screen material), 60 total (15 each side of each vee)

Bypass channel is 2’ wide expanding to a 3’ pipelines

3- 8’ x 30’ holding ponds with mechanical crowder. Ponds would have a minimum 4 ft depth and would fluctuate to the full operational range to a lake level of 530.

The Monitoring/Evaluation/Transport facility would be sized to hold 420,000 juvenile fish for sorting and transport.

The juvenile and adult collection facility will include facilities to do a water-to-water transfer of juveniles into a specially-designed tanker truck.

Juvenile and adult transport trucks (3) will include life support systems such as cooling and waste disposal to ensure the juveniles are successfully released to the lower Yuba River. Three trucks will allow flexibility and redundancy for successful fish transport.

Penstock isolation gate(s) will be provided

A stoplog system will be provided at the upstream end of the fish screen for isolation and protection.



The proposed fish passage facility at Narrows 2 would include the following elements:

Fish screen to keep juvenile anadromous salmonids out of the Narrows 2 Powerhouse,

Fish will be routed to a collection facility to capture, tag and otherwise study juveniles,

Loading and transport facility will provide water to water safe transfer of fish from the holding area to the transport vehicles to return them to the lower Yuba River

Both adult anadromous salmonids moving upstream and juvenile and adult fish migrating downstream would potentially be drawn into the Narrows 2 Powerhouse intake tower,



therefore a fish screen is needed to ensure they would not be drawn into the Narrows 2 intake and Powerhouse.

The fish screen on the Narrows 2 Powerhouse intake would be designed to limit effects of juvenile spring-run Chinook salmon and steelhead on Narrows 2 Powerhouse operations, and to limit entrainment of juvenile salmon at the Narrows 2 Powerhouse intake. .

Fish screens will be constructed on the west side of the reservoir upstream of the dam and excavated into the hillside to provide sound foundation. The screen structure would not be designed to be dewatered under full pool due to uplift. Maintenance is assumed to be done via divers or by lowering of the reservoir. Rock anchors and/or Micropiles are expected to provide safe operating differentials. For estimating, 8-inch diameter Micropiles, 30 feet long at 8-feet spacing have been assumed.

A trashrack will be provided at the upstream end of the screen structure to manage debris to size that can be bypassed through the system. Kelt passage windows would be included in the rack design to allow movement of adults downstream to the holding area. Automated trash rakes would be provided.

Twin Fish screens would be required to screen the 3,400 cfs flow. Each would include primary screens and secondary screens sized to pass 100% of the generation flow. Automated screen cleaners will be installed on all screens to regularly clean 100% of the required screen area.

A fish bypass system at the downstream end of the secondary screens will route fish from the screens to the Monitoring and Evaluation Facility holding ponds.

An automated penstock isolation gate would be provided at the entrance to the penstock. The gate will be a 20 ft roller gate with an actuator.

The Monitoring and Evaluation facility would be excavated into the shoreline to a main floor elevation of 511. The structure would be exposed to the full reservoir water elevations so the walls would extend to elevation 545 to protect the facility to the 100 yr level. The structure would not be designed to be dewatered under full pool due to uplift. Rock anchors and/or Micropiles are expected to provide full uplift resistance for the structure. For estimating, 8-inch diameter Micropiles, 60 feet long at 8-feet spacing have been assumed.

The Monitoring and Evaluation facility will provide temporary holding for all captured fish from the fish screens until they can be processed and/or transported. The fish bypass pipe would discharge into a distribution channel that would automatically direct fish to the active holding pond(s). Fish would be sorted and either returned to the lake or transported downstream.

Bypass flow will be determined to ensure efficient capture and transport of fish and is expected to be 10 cfs to 40 cfs for each vee. Final screening will be provided in the distribution channel to remove flow in excess of that which is routed through the holding ponds.

Three holding ponds are provided to allow continuous holding and processing of fish. Refuge racks to allow age class separation within the holding ponds would be required.



Water flow to the Monitoring and Evaluation facility will be regulated by a series of four 50hp pumps having an installed capacity to handle the maximum flow plus a standby pump. These pumps would need to lift the water about 15 ft to allow discharge back to the lake.

Operation and Maintenance: The fish screen and collection/transport facility would require year-round daily inspection by a team of two workers to assure the system is functioning properly. Minor monthly maintenance and more advanced annual maintenance would be required for fish screen sediment removal, screen cleaning system, utility water pumps, monitoring facility water pumps, gantry hoists, trash rack rake, and other miscellaneous valves, gates, piping, and instrumentation. It is assumed that a team of two operators would be required to load and transport collected fish.

Electrical power would be required to operate the pumps and mechanical system noted above. The fish transport trucks would require regular fueling, as well as routine maintenance. Periodic inspection and exercising of the backup diesel generator would be required.


The use of a bypass pipe rather than capture and transport was considered but was rejected for several reasons:

Narrows 1 and Narrows 2 Bypass pipes would likely need to be combined to allow one pipe to be routed down the canyon, complicating operation of the facilities.

Bypass pipeline would be more than 4,000 feet long and construction would be difficult and expensive in the steep rock canyon. A road would need to be constructed for pipeline maintenance access.

Bypass pipeline routed on steep canyon walls would be susceptible to catastrophic failure from rockslides.

Accommodating expansion/contraction of the pipeline due to large ambient temperature range in the canyon, while maintaining a smooth inner pipe surface for fish safety, would be technically challenging.

7.2.4 Construction of a Juvenile Release Facility on the Lower Yuba River (Element 4)

This facility is presented in Section 2 Action 1– Collect and Transport North Yuba River, Section 2.2.8.

7.2.5 Construction of a tailrace barrier at New Colgate Powerhouse (Element 5)

This facility is presented in Section 5 Action 4– Englebright Dam Removal, Section 5.2.14.

7.2.6 Construction of a Fish Ladder at Our House Dam (Element 6)


7.2.7 Construction of a Fish Screen and Juvenile Return on the Lohman Ridge Tunnel Diversion (Element 7)




7.2.8 Improvement of North Yuba River Habitat Below New Bullards Bar Dam (Element 8)

This Element is described in Section 5 Action 4– Englebright Dam Removal, Section 5.2.5.

7.2.9 Improvement of New Bullards Bar Reservoir Low-Level Release Outlet Reliability (Element 9)


7.2.10 Reoperation of NID’s Yuba-Bear Project (Element 10)


7.2.11 Reoperation of PG&E’s Drum-Spaulding Project (Element 11)


7.2.12 Reoperation of YCWA’s YRDP (Element 12)


7.2.13 Restoration of Water Supply to NID and PCWA Customers (Element 13)


7.2.14 Restoration of Hydropower Generation Value to NID and PG&E (Yuba-Bear and Drum-Spaulding Complexes) (Element 14)


7.2.15 Restoration of Hydropower Generation Value of Narrows 1, 2, and New Colgate Facilities. (Element 15)


7.2.16 Improved Passage at Daguerre Point Dam (Element 16)


7.2.17 Monitoring and Evaluation (Element 17)

This element is discussed in Section 2 Action 1 – Collect and Transport North Yuba River, Section 2.2.14.

7.3 ADDITIONAL ASSESSMENT REQUIRED FOR ADVANCED DESIGN

The following is a list of studies, assessments, and additional evaluations that will be needed to develop this action and its elements beyond this initial concept screening level:

Actions and Elements will need to be optimized for design, construction cost, and operational efficiency. Likely this optimization would require a) a set of biological and operational goals, which would lead to refined design criteria, b) additional physical site analysis (including access, ownership, power sources, geotechnical, etc.), c) legal, regulatory and permitting considerations all developed and included in design criteria, d) site location optimization in consideration of geotechnical and flooding hazards, e) facility design optimization to address cost and operational considerations, f) final design process to include all of the aspects and considerations developed in the optimization process.



Prior to final design, a structural analysis of Englebright Dam would be required to determine if the facilities proposed to be constructed on top of, attached to, and adjacent to the dam would impact the dam’s stability or performance under all flow and storage conditions. The proposed fish ladder and appurtenances would need to be designed and constructed in such a manner as not to compromise the dam strength and or ability to endure a PMF event.

Analysis and a method or approach for addressing water temperature differential between the upper end of the ladder (assuming water temperatures have been maintained for its full length,) and the epilimnion of Englebright Reservoir.

Detailed analysis of fish behavior relative to extended length ladders

Detailed analysis of the predator fish stocks in Englebright Reservoir

A method or approach for addressing water temperature differential between Englebright Reservoir and the South Yuba River would be required. Potential operational changes improving habitat in the upper South Yuba River would likely include increases in South Yuba River flow, but it is likely a temperature differential of greater than 10 degrees Fahrenheit would remain between water temperatures in Englebright reservoir and at the lower end of the South Yuba River, given the limitations of water storage in the South Yuba and the length and exposed aspect of the reach; it is unclear (potentially unlikely) that anadromous salmonids would volitionally leave the cool temperatures of Englebright Reservoir area, released through the New Colgate Powerhouse, for the South Yuba River. An analysis describing the frequency and persistence of substantial temperature differential would be required to provide an indication of potential anadromous salmonids behaviors and approach for mitigation would need to be developed.

A method or approach for addressing water temperature differential between Yuba River below and above the New Colgate Powerhouse would be required. As in the South Yuba River, potential operational changes to improve habitat for anadromous salmonids in the lower North Yuba River and in the Middle Yuba River are being contemplated, but the issue of attracting fish to those habitat areas needs to be addressed. It is likely that the water temperature differential of flow below and above the New Colgate Powerhouse would frequently exceed 10 degrees Fahrenheit. Analysis characterizing this water temperature differential and the frequency at which it could occur needs to be completed to provide an indication of the likelihood anadromous salmonids would continue past the New Colgate Powerhouse towards the lower North Yuba or Middle Yuba rivers. Furthermore, with increased releases from New Bullards Bar Dam to support anadromous salmonids in the North Yuba River, there would likely be a substantial temperature differential, perhaps of more than 10 degrees Fahrenheit, at the confluence of the North Yuba River and Middle Yuba River. What is the likelihood that fish would select the Middle Yuba River over the colder, but limited length and poorer quality habitat of the lower North Yuba River?

Considering the relatively cold water temperatures coming out of New Bullards Bar Reservoir, even at low flows, it may be necessary to install a fish passage barrier at the confluence of the North and Middle Yuba rivers to encourage fish to migrate into the Middle Yuba River, which would be warmer but would contain a greater total quantity of



available habitat than the two miles of North Yuba between New Bullards Bar and the confluence of the North Yuba and Middle Yuba rivers. If such a barrier were constructed, the purpose of increased releases out of New Bullards Bar Reservoir would be called into question.

An analysis of temperatures and temperature impacts in the reach between Colgate Powerhouse and the Feather River would be necessary. Currently, temperatures in on the lower Yuba River are at least suitable and potentially optimal. . Moving the source of cold water for the Lower Yuba River further upstream (Colgate powerhouse instead of Narrows 2 powerhouse), and reoperation of the projects on the upper Middle and South Yuba rivers to increase the flow from those two rivers to the lower Yuba River could substantially change the temperature profile of the lower Yuba River. A higher proportion of lower Yuba River flow coming from the Middle and South Yuba rivers, and a correspondingly reduced portion from New Bullards Bar Reservoir, would likely result in lower Yuba River water temperatures would be warmer than they are under current operations. If analysis indicates a problem, potential remedies should be identified.

Analysis of water supply and generation impacts to upstream projects (NID’s Yuba-Bear and PG&E’s Drum-Spaulding projects) will need to be completed, and remediation measures (if required) designed.

Design of habitat improvements for the reach between New Bullards Bar Dam and the confluence of the North Yuba and Middle Yuba Rivers.

Development of operations plans for the YRDP.

Assessment of native fish populations (including predators) in upstream reaches, and development of strategies to manage or mitigate impacts from or to native populations

Uncontrolled spills over the top of Englebright Dam are a frequent occurrence in winter and spring months, the impacts of such spills both on physical facilities (fish ladder) and on out-migrating juvenile salmonids needs to be carefully assessed.

Development of a permitting plan for all improvement projects, completion of CEQA processing, completion of NEPA processing (for all projects with a Federal nexus), securing of 404, 401, 1600 and other necessary permits and authorities.

7.4 OTHER CONSIDERATIONS

This section describes other considerations associated with the proposed Action.

7.4.1 Benefits of Action

A ladder over Englebright Dam would avail all habitat on the Middle, South and lower North Yuba River to anadromous salmonids on a semi-volitional basis.

7.4.2 Challenges of Action

Research has not identified the successful implementation over a dam of this height elsewhere within the US.

Water temperature differential between the upper end of the ladder and the epilimnion of Englebright Reservoir could have a negative impact on fish exiting the ladder into Englebright Reservoir.



With two powerhouses, and the associated intakes, screening and collecting juveniles will be complicated. It might be preferable to construct a single Floating Surface Collection (FSC) and handling facility, if it is decided that one is necessary. A FSC in Englebright Reservoir, similar to the one described in the North Yuba River Collect and Transport action (Action 1, Section 2 of this Report), would be a potential opportunity to construct a single collection facility. Unfortunately, there are challenges in operating a FSC and a fish ladder at the same general location and timeframe; if the FSC nets were upstream from the ladder exit, they would block access to all habitat upstream from the nets. If the FSC were downstream from the ladder exit, the exit chute length would likely increase and there is a potential for loss of juveniles near the fish ladder exit where they might be exposed to increased predation, and screens would still be required on the Narrows 1 and 2 powerhouses.

Fish migrating to the upper watershed could be stranded if flows were to drop below suitable levels due to a dry hydrologic condition. Re-operation of the Middle and South Yuba River projects needs to take into consideration a potential for ensuring attraction and survival for adults if forecasted conditions indicate dry hydrology, with low flow and warm water temperatures. This could ensure adults stay in the Englebright Reservoir rather than attempting continued upstream migration. Another potential option could include some sort of exclusion weir to preclude adults from migrating into potentially unsuitable habitat. These approaches would be at odds with the concept of volitional passage.

Fall run Chinook salmon would be free to migrate to newly available habitat, sustaining the existing challenges of competition and a reduction of genetic differentiation between fall and spring run Chinook salmon. A segregation weir to exclude continued upstream migration of fall-run Chinook salmon could be constructed to separate fall-run Chinook salmon from spring-run Chinook salmon, if competition and introgression continued to present a problem.

Even with a ladder over Englebright Dam, existing natural barriers on the South, Middle, and lower North Yuba River could substantially limit habitat for anadromous salmonids. These natural barriers exist in the upper reaches of each tributary, potentially blocking access to areas with the most preferential habitat.

An increase in flow requirements on the Middle and South Yuba rivers would likely result in a decrease in diversions from NID’s Yuba-Bear Project, and PG&E’s Drum-Spaulding Project, and a corresponding decrease in water supply to NID and PCWA customers and currently existing fisheries resources in the Bear and American River watersheds, which could not be easily replaced. This would likely be a source of concern to local residents and businesses and could generate significant opposition to the implementation of this Action.

There could also be a decrease in releases to the Bear and American rivers or an increase in diversions from the Bear or American rivers to make up for reductions in deliveries from the Yuba River which could reduce suitable anadromous salmonid habitat in those rivers. Accordingly, there could be potential impacts to other customers or anadromous fisheries along the Bear and American rivers.



Long-term restoration of the North Yuba River downstream from New Bullards Bar Dam, including the injection of suitable substrate to support various life stages, could be challenging given the frequency of high flow releases from New Bullards Bar Reservoir. The reach has its current composition due to the scour of fine materials during spill events; sustaining habitat under these conditions will be difficult.

Some form of exclusion weir may be needed to keep adults from migrating up Oregon Creek from the Middle Yuba River. There may be an attraction into Oregon Creek, but since releases from Log Cabin Dam will not likely be high enough to support anadromous salmonids through the summer and fall, there is a potential for stranding, reduced survival of adults, and reduced viability of eggs below the dam. Accordingly, it is undesirable for anadromous salmonids to be in Oregon Creek.

Documents

YSF Action 6 - Fish Ladder Over Existing Englebright Dam … · 2013-03-21 · Fish Passage Infrastructure Report SECTION 7.0 ACTION 6 - FISH LADDER OVER EXISTING ENGLEBRIGHT DAM