HomeMy WebLinkAboutReynolds Creek Hydroelectric Project Design Report - Aug 2010 - REF Grant 2195323Haida Energy, Inc.
Reynolds Creek Hydroelectric Project
FERC Project No. 11480
Supporting Design Report
August 2010
500 108th Avenue NE
Suite 1200
Bellevue, WA 98004-5549
(425) 450-6200
Reynolds Creek Hydroelectric Project i
Supporting Design Report August 2010
Table of Contents
1.0 INTRODUCTION ...................................................................................... 1
1.1 Purpose of Project .............................................................................................. 1
1.2 General Project Setting and Location .................................................................. 1
1.2.1 Survey Control ......................................................................................... 1
1.3 Drainage Area ..................................................................................................... 2
1.4 Mode of Operation .............................................................................................. 2
1.5 Estimated Project Cost........................................................................................ 3
1.6 Schedule ............................................................................................................. 3
1.7 Design Standards ............................................................................................... 4
2.0 Existing Conditions ................................................................................. 5
2.1 Hydraulics and Hydrology ................................................................................... 5
2.2 Geotechnical ....................................................................................................... 5
2.2.1 General Geology ..................................................................................... 6
2.2.2 Economic Mineral Deposits ..................................................................... 6
2.2.3 Erosion and Mass Movement .................................................................. 6
2.2.4 Faults, Shear Zones, and Joints .............................................................. 7
2.2.5 Seismicity ................................................................................................ 7
2.2.6 Volcanic and Geothermal Activity ............................................................ 7
2.2.7 Soils ........................................................................................................ 7
3.0 PROJECT COMPONENTS.......................................................................... 8
3.1 Marine Access .................................................................................................... 8
3.2 Diversion/Intake .................................................................................................. 8
3.2.1 Civil ......................................................................................................... 8
3.2.2 Structural ................................................................................................. 9
3.2.3 Mechanical .............................................................................................. 9
3.2.4 Electrical .................................................................................................. 9
3.3 Fish Screen Criteria ...........................................................................................10
3.3.1 Civil ........................................................................................................10
3.3.2 Structural ................................................................................................10
3.3.3 Mechanical .............................................................................................11
3.3.4 Electrical .................................................................................................11
3.4 Penstock ............................................................................................................11
3.4.1 Civil ........................................................................................................11
3.4.2 Structural ................................................................................................11
3.4.3 Mechanical .............................................................................................12
3.4.4 Electrical .................................................................................................12
3.5 Powerhouse .......................................................................................................12
3.5.1 Civil ........................................................................................................12
ii Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
3.5.2 Structural................................................................................................13
3.5.3 Mechanical .............................................................................................13
3.5.4 Electrical .................................................................................................21
3.6 Tailrace..............................................................................................................26
3.6.1 Civil ........................................................................................................26
3.6.2 Structural ................................................................................................26
3.6.3 Mechanical .............................................................................................26
3.6.4 Electrical .................................................................................................26
3.7 Transmission Line/Switchyard ............................................................................27
3.7.1 Civil ........................................................................................................27
3.7.2 Structural ................................................................................................27
3.7.3 Mechanical .............................................................................................27
3.7.4 Electrical .................................................................................................29
4.0 GENERAL STRUCTURAL ANALYSIS AND DESIGN ................................. 30
4.1 Codes, Standards, and References ...................................................................30
4.1.1 Purpose ..................................................................................................30
4.1.2 Codes and Standards .............................................................................30
4.2 Computer Programs ...........................................................................................31
4.3 Materials ............................................................................................................31
4.4 Loads .................................................................................................................32
4.4.1 Structural Analysis ..................................................................................34
4.4.2 Internal Loads in Penstock .....................................................................34
4.4.3 Water Properties .....................................................................................34
4.4.4 Air Temperature ......................................................................................35
4.4.5 Foundation Design .................................................................................35
List of Tables
Table 1. Technical turbine performance envelope. ...................................................................14
Table 2. Minimum vertical ground clearance requirements .......................................................29
List of Figures
Figure 1. Reynolds Creek Annual Flow Duration Curve. ........................................................... 5
Reynolds Creek Hydroelectric Project iii
Supporting Design Report August 2010
List of Appendices
Appendix A1 Renshaw Geotechnical Report
Appendix A2 Shannon & Wilson Geotechnical Report
Appendix B Instream Flow Pipe Calculations
Appendix C Marine Access Technical Memorandum
Appendix D Diversion Dam Spillway Calculations
Appendix E Surge Analysis Report
Appendix F1 Steel Penstock Calculations
Appendix F2 Penstock Anchor Calculations
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Reynolds Creek Hydroelectric Project 1
Supporting Design Report August 2010
1.0 INTRODUCTION
1.1 Purpose of Project
The purpose of the Reynolds Creek Hydroelectric Project is to generate renewable power
and energy to serve the community of Hydaburg, Alaska. The project will ultimately provide
power and energy to the remainder of Prince of Wales Island. The development of this
renewable energy project will replace existing diesel powered generation facilities on the
island. The replacement of these facilities will initially reduce diesel consumption by
115,000 gallons per year. When the project is fully utilized it will reduce diesel consumption
by approximately 1.6 million gallons per year.
1.2 General Project Setting and Location
The Reynolds Creek Hydroelectric Project site is located in the Prince of Wales – Outer
Ketchikan (CA) Borough on the southwest side of Prince of Wales Island in southeast
Alaska approximately 10 air miles east of Hydaburg, approximate latitude 55o 14’ and
longitude 132o 36’. Specifically, the Project is located in T77S, R85E, in Sections 3 and 4.
Reynolds Creek is a high-gradient stream that originates in the mountains to the north and
east of Copper Harbor and flows to the sea at Copper Harbor through a steep narrow
canyon that widens with decreasing gradient from about the 100 foot elevation above mean
sea level (amsl).
The project consists of a small diversion dam and intake at the outlet of Rich’s Pond (Lake
Mellen), a instream flow pipe, a steel penstock, a powerhouse, access roads, and an
overhead 34.5 kV transmission line. Construction of the project will include the
diversion/intake, penstock, access roads, transmission line and a 5 MW powerhouse.
With the exception of the area of Hetta Inlet affected by the aerial crossing of the
transmission line, all project lands are privately held by the Sealaska and Haida Energy, Inc.
Haida Energy, Inc. intends to obtain a real property interest for all project lands through a
negotiated settlement with the Sealaska Corporation. An Application for Right-of-Way or
Easement has been submitted to the Alaska Department of Natural Resources for the aerial
transmission line crossing of Hetta Inlet.
1.2.1 Survey Control
Survey data was provided by Sentec surveying.
Horizontal Control
Pt # 1 located in Copper Harbor was held as the “Basis of Coordinates”. An OPUS
solution was obtained from NGS (National Geodetic Survey) in Alaska State Plane Zone
1 and 83. The GPS control was constrained at this point to those coordinates. The
“Basis of Bearing” on this plat was determined by a high-precision GPS survey using
Trimble 5700 receivers differentially corrected and processed using Trimble Geomatics
Office V1.62 software.
Vertical Control
The vertical adjustment of the GPS control was computed using Alaska Geiod 06.
Control point # 1 located in Copper Harbor was held as the Basis of Elevation. This point
was tied to the Tidal datum with a series of level shots to the water line at different tidal
times and dates. From this data a shift was made from the GPS elevations to the tidal
datum of MLLW. All Sentec points were shifted relative to this elevation. Aero-Metric
then shifted their datum to match the Sentec Data.
2 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
1.3 Drainage Area
The Reynolds Creek drainage area, consisting of 5.2 square miles, is primarily located in
T76S, R84E, Section 36; T76S, R85E, Sections 31, 32, 33; T77S, R85E, Sections 1, 2, 3, 4,
10, 11, 12; and T77S, R86E, Sections 6, 7 on Prince of Wales Island, Alaska. The elevation
in the basin varies from the natural Lake Mellen elevation of 872 feet mean sea level (fmsl)
to a high of approximately 2,800 feet and is generally oriented in a southwesterly direction.
The basin includes three lakes: Lake Marge (1,750 fmsl approx.); Summit Lake (1,318 fmsl);
and Lake Mellen (876 fmsl). The mean basin elevation is approximately 1,600 feet. The
drainage basin surrounding Lake Mellen is primarily steep with slopes averaging about 50%.
The basin is generally forested with areas of muskeg near the lakes and tributary streams
and exposed bedrock outcroppings in the higher elevations. The estimated average annual
flow of Reynolds Creek at the point of diversion is 57 cubic feet per second (cfs). A
derivation of the long-term hydrology and annual and monthly flow duration curves are
presented in Appendix B.
1.4 Mode of Operation
The Reynolds Creek Hydroelectric Project will operate almost entirely in a run-of-the-river
mode, generating electrical energy based on system load and available stream flow. During
normal operation, water will be continuously released into the bypass reach through the low
level outlet of the diversion. Any additional water up to the desired turbine flow will be
diverted through the powerhouse and returned to Reynolds Creek near the anadromous fish
barrier. Turbine flow will range from a minimum of about 5 cfs to a maximum of 90 cfs
depending on the electrical load of the system and the installed capacity. Lake Mellen will
be used to synchronize the daily variations in electrical load with the daily variations in
inflow. In all but extremely dry hydrologic periods, the water balance of upper and lower
Reynolds Creek will be the same on a weekly, if not daily, time frame.
A typical mode of operation for an impulse-style turbine is to set up the turbine such that
when generation is interrupted for any reason, the deflectors are automatically swung into
position to divert flow away from the rotating water wheel. This is a standard method used
to maintain flow through an impulse turbine until a plant operator can assess the reason for
the plant shutdown. Flows through the turbine would be reduced to a minimum level of
approximately 5 cfs when the deflectors are in place. If, as is often the case, the unit could
be restarted within a short amount of time, the deflectors would be left in place until the unit
is restarted. If, however, it is clear that the turbine will be out of service for an extended
period, flow through the jets would be slowly shut-off.
Three likely control modes are probable for the project. In the first control mode, the project
would be responsible for governing system frequency. As such, the project would be
required to react to load swings (“load following”) by increasing or decreasing output from
the project. This would be the control mode in the early years when the project is used to
meet the needs of Hydaburg exclusively. Once the project becomes an integrated resource
in the larger Prince of Wales Island electrical system, it is probable that the project would
see an additional two modes of operation, “block” loading and “level control”. When block
loaded, the project would operate at a desired output level and, therefore, relatively constant
flow level. When under level control, the project would be operated to maximize the
generation from the available water while maintaining a constant pool elevation in Lake
Mellen. In this case, inflow into Lake Mellen will be equal to outflow. In these latter two
modes, governing, or control, of the system frequency would be performed by one of the
other generating resources in the interconnected system. The pool elevations in Lake
Reynolds Creek Hydroelectric Project 3
Supporting Design Report August 2010
Mellen are to operate between 876.0, the spillway crest elevation and the minimum pool
elevation of 872.0.
When the project is operating in either a load following or block loaded mode, storage will be
used when the turbine flow required to meet the load is in excess of inflow. When the
turbine flow required to meet the load is less than the lake inflow, storage will be increased
or, if the lake elevation is at the spillway crest, the excess water will be spilled. Due to the
limited storage available in Lake Mellen, the length of time and the frequency of which the
project could operate in these modes is a function of the amount of inflow to Lake Mellen
and the magnitude of the load to be met.
1.5 Estimated Project Cost
The estimated cost of the project is $17,245,000. This cost includes construction, permits,
engineering, administration, and contingencies.
1.6 Schedule
Haida Energy, Inc. anticipates the following general construction schedule for the Project:
Access Roads
Repair road to Deer Bay .......................................................... October 2010
Repair road, Copper Harbor to Jumbo Island ................................ May 2011
Repair road to Lake Mellen ...........................................................June 2011
Construct diversion access road ...................................................June 2011
Construct powerhouse access road/tailrace trail ............................ July 2011
Marine Access Facilities
Construct boat ramp/staging area at Deer Bay ........................ October 2010
Construct dock/boat ramp at Copper Harbor ......................... April-May 2011
Construction Camp at Copper Harbor
Install site utilities ............................................................... March-April 2011
Install structures .................................................................... April-May 2011
Transmission Line
Construct Hydaburg to Jumbo Island segment ..................... December 2010
Construct Copper Harbor to Jumbo Island segment............... May-July 2011
Construct Jumbo Island crossing segment ......................... July-August 2011
Diversion Structure
Install temporary diversion culvert and cofferdam .............. July-August 2011
Excavate and grout spillway foundation ................ September-October 2011
Construct spillway ................................................................. April-May 2012
Construct intake ..................................................................... April-July 2012
Breach cofferdam/remove temporary diversion culvert ...... July-August 2012
Excavate Lake Mellen outlet channel ................................. July-August 2012
Penstock
Construct upper section (600 feet) .................................. June-October 2011
Construct middle section (2400 feet) ............................... April-October 2012
Construct lower section (200 feet) ...................................... March-April 2012
Powerhouse
Construct building foundation ........................... September-November 2011
Erect metal building ..................................... December 2011-January 2012
Install generating and auxiliary equipment ................. June-September 2012
Switchyard
Construct equipment foundations............................................. October 2012
4 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
Install equipment..................................................................November 2012
Tailrace
Excavate from powerhouse to creek .............................................. July 2011
Construct outfall ................................................................. July-August 2011
Install tailrace pipe ................................................. August-September 2011
Connect plunge pool to creek ............................................ July-August 2011
Completion
Test systems and start up equipment……………… ............. December 2012
1.7 Design Standards
Design will be in accordance with or exceed the latest applicable standards:
1. American Concrete Institute (ACI)
2. American Institute of Steel Construction (AISC)
3. American Iron and Steel Institute (AISI)
4. Aluminum Association
5. American National Standards Institute (ANSI)
6. American Society for Testing and Materials (ASTM)
7. American Society of Mechanical Engineers (ASME):
8. American Society of Civil Engineers (ASCE)
a. ASCE Manual and Reports on Engineering Practice 79, “Steel Penstocks”, 1984.
9. American Welding Society (AWS)
10. ASTM International (ASTM)
11. Certified Ballast Manufacturers (CBM).
12. Edison Electric Institute (EEI)
13. Federal Communications Commission (FCC):
a. Rules and Regulations, Part 18:
14. Code of Federal Regulations (CFR), 47 CFR 18, Industrial, Scientific and Medical
Equipment.
15. Illuminating Engineering Society (IES)
16. Institute of Electrical and Electronic Engineers (IEEE)
17. Insulated Cable Engineers Association (ICEA)
18. National Board of Fire Underwriters (NBFU)
19. National Bureau of Standards (NBS)
20. National Electrical Manufacturers Association (NEMA):
a. 250, Enclosures for Electrical Equipment (1000Volts Maximum).
b. 82.1, For Lamp Ballast - Line Frequency Fluorescent Lamp Ballast. (Multiple-
Supply Type).
c. C82.11, High Frequency Fluorescent Lamp Ballast - Supplements.
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Supporting Design Report August 2010
21. National Electric Safety Code (NESC)
22. National Fire Protection Association (NFPA):
a. 70, National Electrical Code (NEC).
23. Alaska Occupational Safety and Health (AKOSH)
24. Underwriters Laboratories, Inc. (UL).
25. Applicable Local Codes
2.0 Existing Conditions
2.1 Hydraulics and Hydrology
The hydrologic analysis will utilize the Reynolds Creek flow duration curve developed in a
previous phase of analysis.
Figure 1. Reynolds Creek Annual Flow Duration Curve.
2.2 Geotechnical
Two geotechnical reports have been prepared for the project. The first geotechnical report
was prepared in May 1997 by Dan Renshaw, a Consulting Engineer. The second
geotechnical report was prepared in September 2008 by Shannon and Wilson. Both these
reports have been included in this report, as Appendices A1 and A2, respectively. The
following subsections provide a brief summary of the geologic and geotechnical conditions
summarized for the site in these reports.
0
50
100
150
200
250
300
350
400
0 10 20 30 40 50 60 70 80 90 100Flow (cfs)Exceedance (%)
Reynolds Creek
Annual Flow Duration Curve
6 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
2.2.1 General Geology
Southeastern Alaska has been tectonically active since the early Paleozoic Era and has a
complex geologic and structural history. It is divided into several geologic terranes, each of
which has a unique geologic history. The terraness are bounded by faults which are
generally major lineaments that follow the valleys, coastlines, and inlets of southeastern
Alaska.
Southeast Alaska was glaciated during the most recent ice age, which ended about 10,000
years ago. At that time, continental ice thickness was in the range of 3,000 feet. The ice
depressed the land and smoothed the topography. The land then rebounded, elevating
some marine deposits several hundred feet above sea level. Alpine glaciations also
affected the higher mountains of the region, carving U-shaped valleys, cirques, arêtes, and
hanging valleys.
In the proximity of POW Island, the geology is dominated by the Alexander terrane. The
Alexander terrane is comprised of stratified, metamorphic, and plutonic rocks that range in
age from Precambrian to Cambrian through Middle Jurassic. The Project is located in the
Craig subterrane, one of several sub-units located within the larger Alexander terrane
geologic unit.
The oldest rock types in the Craig subterrane are the arc-type metasedimentary and
metavolcanic rocks of the Wales group that were metamorphosed and deformed during the
Middle Cambrian to Early Ordovocian Wales orogeny. These rocks formed the depositional
and intrusive basement for the arc-type volcanic-plutonic-sedimentary complex of the Early
Ordovician to Early Silurian age. From the Middle Silurian to earliest Devonian, the
southern portion of the Alexander terrane (including the Craig terrane) experienced the
Klakas orogeny, characterized by southwest vergent thrusting, regional metamorphism and
deformation, uplift and erosion, and generation of plutonic bodies. The upper Paleozoic
strata consist of shallow marine carbonate rocks, clastic rocks, and volcanic rocks which
have subsequently undergone extensive erosion. The Upper Triassic strata consist of a
basal conglomerate and sedimentary breccia followed by rhyolite and rhyolitic tuff, massive
limestone, calcerous argillite, and basaltic-andesitic pillow flows of breccia.
Project area geology is dominated by three geologic units. The lower reach of Reynolds
Creek and shoreline of Copper Harbor consist of Late Precambrian carbonate rocks, marble
of the Wales Group, and Cretaceous thermally metamorphosed hornfelsic rocks rich in
albite-epidote and garnet. The upper reach of Reynolds Creek, Lake Mellen, and Summit
Lake are mapped as Cretaceous Granodiorite.
2.2.2 Economic Mineral Deposits
Mining occurred in the project area in the early 1900’s. The Copper Mountain Mine was
located on the south side of Copper Mountain and was operated by the Alaska Copper
Company. The deposit was discovered in 1897. At the height of its operation, the mine
consisted of more than 3,600 feet of tunnels, 435 feet of shafts and raises, numerous pits,
an aerial tram, and an Allis-Chalmers smelter capable of processing 250 tons of ore per day.
Production was halted in 1907 and resumed again in 1914, but reportedly failed to produce
additional ore. In addition to copper, the mine produced silver and gold. Remnants of the
mine (Coppermount) are still visible.
2.2.3 Erosion and Mass Movement
Existing slopes in the project area appear to be relatively stable and there is no evidence of
gross hillside movement. Minor surficial soil creep occurs but is confined to the top 1-2 feet
Reynolds Creek Hydroelectric Project 7
Supporting Design Report August 2010
of loose clayey, silty, sandy top soil and organic cover that on or near steep slopes. This
type of movement is common on saturated, steep slopes underlain by rock. Mass wasting
(large block failure) occurs along the vertical cliffs of Reynolds Creek canyon and along
steep slopes.
2.2.4 Faults, Shear Zones, and Joints
Located on the Circum-Pacific Earthquake Belt, the project area is subject to a relatively
high potential for earthquake activity and an intricate network of reverse, normal and strike-
slip faults dissects Southeastern Alaska. To the west, the area is truncated at the North
American continental margin by the Queen Charlotte-Fairweather fault system. This system
is known to be an “active” right-lateral fault with large displacements. The location of this
fault, which represents the plate boundary between North America and the Pacific Plate, is
approximately 60 to 70 miles southwest of Hydaburg. Two other major fault systems, the
Clarence Strait and Chatham Strait Faults run approximately north-south along the eastern
shore and to the west of Prince of Wales Island, respectively. The Clarence Strait system is
a left-lateral strike slip fault. It is believed to have approximately 9 miles of displacement.
The Chatham Strait fault, which was active in the Tertiary Period (2 to 65 million years ago),
is believed to have offset rocks as much as 95 miles. This fault truncates in the south at the
Queen Charlotte-Fairweather fault. Many other smaller faults and shear zones splay off from
these major features and have been mapped or inferred throughout the region.
2.2.5 Seismicity
Southeast Alaska lies in an active seismic zone. Regional seismicity appears to be primarily
controlled by north-south strike-slip motion between the North American and Pacific Plates
of the west coast of the Alexander Archipelago.
The nearest historic earthquake to the site was a magnitude 5.0 event located within 10
miles of the project area. A magnitude 6.4 event occurred approximately 60 miles
southwest of the site.
Large earthquakes in the region include the August 21, 1949, Queen Charlotte Islands and
July 30, 1972, Sitka events. The 1949 magnitude 8.1 earthquake was located
approximately 120 miles southwest of the site. The 1972, magnitude 7.6 event was located
about 140 miles northwest of the site.
2.2.6 Volcanic and Geothermal Activity
No volcanic or geothermal activity has been identified in the vicinity of the proposed project.
2.2.7 Soils
Soils in the upper part of the drainage have developed from a variety of organic and
inorganic sources. Inorganic soils have developed from glacial deposits, uplifted marine
sediments, and metamorphic and igneous rocks. The organic soils have developed from
deposits of decomposed plant material that is found in poorly drained areas associated with
low relief. Soil deposits in the vicinity of Copper Harbor and the mouth of Reynolds Creek
appear to be a combination of glacially derived soil and floodplain deposits with an
estimated thickness of up to 10 feet. Soils along the lower reach of Reynolds Creek are
comprised of alluvium up to 10 or more feet thick. This soil is less cohesive and is
susceptible to erosion by surface water.
Soils in the upper reach of Reynolds Creek are generally stable, due in large part to rocky
terrane, rock outcrops, and the vegetation cover. The stability of some vegetated soil areas
may be affected by the proposed site clearing at the intake, along the penstock route, and at
8 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
the powerhouse site which will remove some of the protective vegetative cover and disturb
the root system.
3.0 PROJECT COMPONENTS
3.1 Marine Access
The marine access facilities will provide a temporary means during construction to transport
materials, equipment, and personnel to and from the landing craft and workboats. These
facilities will not remain serviceable of function beyond the expected 24 month construction
phase.
Further discussion of the design and purpose of the marine access facilities is explored in
the “Marine Access Technical Memorandum”, included in Appendix C.
3.2 Diversion/Intake
A diversion dam will be constructed near the outlet of Rich’s Pond, a small sub-basin at the
outlet of Lake Mellen. The diversion dam structure will consist of a concrete cutoff wall with
grouted riprap on the west side and ungrouted riprap on the east side. The crest length of
the structure will be about 66 feet, which acts as weir with uncontrolled overflow when the
lake is above elevation 876 feet amsl. The length of the crest at the weir overflow elevation
of 876 feet is 23 feet.
The backwater from the dam will inundate Rich’s Pond and interconnect to the existing
surface elevation of Lake Mellen. Access to the diversion will be provided by an existing
logging road and a segment of new road on the north side of Rich’s pond. The new access
road will then cross a temporary diversion dam that will also provide access to the south
side of Rich’s Pond to construct the valve vault and penstock. The location of the access
road to the diversion dam will be based on the recent topography maps and the
reconnaissance geotechnical report performed by Shannon & Wilson (September 2008),
included in Appendix A2.
The intake structure will consist of a stainless steel cylindrical tee screen, located in Rich’s
Pond. The tee screen will be fixed to the raw water supply pipe that feeds the steel
penstock. The screen will prevent debris from entering the penstock. The tee screen will be
supported by steel pipe columns on concrete footings. A valve vault will be located
immediately downstream of the intake along the southwest bank of Rich’s Pond. The valve
vault will house the penstock shutoff valve, operator, and a flowmeter for the instream flow
bypass. Power to the site will operate the screen cleaning system using level control
elements and flow sensors.
An instream flow pipe will bypass the penstock isolation valve to maintain a minimum
uncontrolled instream flow of 12 cfs. This instream flow pipe will provide uninterrupted flow
to the bypass reach downstream of the diversion. The pool elevations in Lake Mellen are to
operate between 876.0, the spillway crest elevation and the minimum pool elevation of
872.0. The instream flow pipe will be sized for the required flows and is designed to be to
be 18 inches in diameter. A 12” orifice plate will be installed at the discharge end of the
instream flow pipe and is sized for the minimum pool elevation of 872.0 The calculations for
sizing the instream flow pipe and orifice plate are included in Appendix B.
3.2.1 Civil
Approximately 2,000 feet of new access road will be required to access the diversion/intake
site. A temporary cofferdam/access road will be needed to construct the diversion dam. A
Reynolds Creek Hydroelectric Project 9
Supporting Design Report August 2010
temporary diversion conduit will be constructed to bypass flows around the temporary
cofferdam. The temporary diversion conduit will be removed, plugged and/or abandoned
upon project completion, depending on site conditions and accessibility. The access road
into the diversion/intake site will be at a maximum slope of 12 percent. The access road will
be 20 feet wide and constructed of a granular fill base and a crushed rock top course. Fill
slopes will be 1.5 H to 1 V and cut slopes will be 1 H to 1 V.
The spillway on the diversion dam has been sized to pass the 100 year probable design flow
of 1,300 cfs. This calculation is included in Appendix D.
3.2.2 Structural
The diversion and intake structures will require a reinforced concrete and grouted rock-filled
diversion dam as well as a reinforced concrete vault and screen supported footings. Section
4.0 contains the design criteria which were used to analyze and design these structures.
3.2.3 Mechanical
The mechanical components of the tee screen intake and automated cleaning system will
consist of the following elements:
Underwater components:
Tee Screen with two, approximately 42 inch diameter by 8 feet long stainless steel
wedge wire screen cylinders;
Two submersible hydraulic motors, gear reducers (one for each cylinder screen) and
associated hydraulic conveyance lines to rotate the cylinder screens during cleaning
operations. Hydraulic conveyance lines will be designed for 3,000 pounds per
square inch (psi) operation with anticipated normal operating pressures less than
1,500 psi. The conveyance lines will be laid along the lake floor to the bank where
the lines shall run through a conduit to the valve vault. Hydraulic oil shall be Chevron
Clarity ISO 32 or equivalent. This oil has been approved for use by NOAA Fisheries,
and unlike vegetable based oils, it will not break down under cold temperatures;
Air bubbler system to measure water pressure differential between inside and
outside the cylinder screens. Air bubbler conveyance lines will be tied to the
hydraulic lines and have the same routing configuration; and
42 inch diameter steel penstock extending from the tee screen to the valve house.
Valve Vault – Screen cleaning, monitoring equipment and controls:
42 inch diameter butterfly valve with automated motorized actuated control;
Flowmeter on the 42-inch diameter penstock
Flowmeter on the 18-inch diameter instream flow bypass
3.2.4 Electrical
Electrical Control Building -
Hydraulic power unit consisting of 460 VAC 3-phase, 30 amp service, 0.5 hp
hydraulic motor;
A small 4 gallon air compressor (minimum 35 psi regulation) to operate the air
bubbler system; and
Various system controls, control panel, and 110 VAC single phase, 20 amp service.
10 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
3.3 Fish Screen Criteria
The fish screen will be the sole source for water intake per the project specifications, and
designed for a maximum water intake of 90 cubic feet per second (cfs). The following
subsections present specific criteria relative to adequate screen area, maintenance features
and facility hydraulics that were considered in the design to assure compliance with
regulatory requirements and the original FERC License issued, October 24, 2000.
3.3.1 Civil
The following is a summary of the intake criteria from the agencies used for the design of
the fish screen intake:
1. Structure Orientation – The screen must be oriented parallel to lake flow towards the
new dam.
2. Velocity – Uniform approach velocity must be provided across the face of the screen.
Approach velocity must be less than 0.8 feet/second (fps) across the face of the
screen. (This velocity was set by a field study of size of fish present. The field study ,
and the associated 2008 Reynolds Creek Fish Sampling site work were completed
by HDR and Pentec.)
3. Screen Cleaning – Provisions may have to be made to automatically clean the entire
fish screen on a timed basis.
4. Sweeping Velocity – Sweeping velocity should be greater than 0.8 feet/second (ft/s)
and less than 3 ft/s.
5. Screen Openings – Screen opening size must not exceed 1.75 millimeters, with a
minimum open area of 27 percent. If the screen is made from wire mesh or
perforated plate, the screen opening size must not exceed 3/32” with a minimum
open area for any choice of screen material of 27 percent.
6. Screen Materials – The screens must be constructed of rigid, corrosion-resistant
material with no sharp edges or projections (e.g., stainless steel, plastic). The
screen material will be a minimum of stainless steel 304 grade.
7. The minimum Reynolds Creek bypass flow will be 12 cfs.
8. The screen cleaning system will be set to activate should a differential of 0.1 ft
occurs between the front of the screen and the back of the screen.
To meet the required maximum approach velocity of 0.8 fps, the size of the screen is
determined by dividing the desired intake flow rate, 90 cfs, by the approach velocity to
obtain the minimum screen area. In this case, the resulting screen area is 112.5 square feet
(sf). To compensate for the structural blinding resulting from the presence of supports
behind flat plate stainless steel screens, 25 percent is added to the screen area.
Considering the screening criterion and the additional area to compensate for structural
blinding, the resulting minimum intake screen area is 141 sf.
3.3.2 Structural
Structural designs of the various components were completed in general accordance with
the design criteria presented in Section 4.0.
Reynolds Creek Hydroelectric Project 11
Supporting Design Report August 2010
3.3.3 Mechanical
A programmable logic controller (PLC / timer and relays shall be used to control the cleaning
cycle and duration. The same hydraulic pump shall be switched over to operate the
hydraulic screen retrieval winch. An operator may utilize a pendulum switch to operate the
hydraulic winch and be able to stand and observe the screen while it is being pulled up or
being lowered.
3.3.4 Electrical
A 7.5 HP, 3 phase, 480vac electric hydraulic pump unit shall be used to power the screens
hydraulic motors. A high torque marine duty hydraulic gear motors using Chevron Clarity®
Hydraulic Oil (or equal)will be used to rotate the cylinders at a rate of approximately .5 rpm.
Both hydraulic motors in the screen shall be driven at the same time requiring 3 – 4 GPM.
This hydraulic pump unit shall be housed in a NEMA 4 enclosure. Also in this enclosure
shall be the directional valves and manifold proximity / docking indicator.
3.4 Penstock
An approximate 3,200-foot-long welded steel penstock will convey water from the intake to
the powerhouse. The penstock will have a diameter of 42 inches corresponding to a
maximum flow rate of 90 cfs. The penstock will have both buried and aboveground modes
of installation, and the above-ground pipelines will be supported on saddle supports with a
maximum support spacing of 32 feet. The penstock will have a polyurethane lining and
coating to provide corrosion protection. Anchor (thrust blocks) will be provided at changes
in alignment and grade as well as at the powerhouse. The penstock will have a leak
detection system installed which will automatically close the intake pipeline isolation valve in
the event that a leak occurs.
The penstock will cross from the left to the right side of Reynolds Creek approximately 1,200
feet upstream of the powerhouse. At this location, the pipe will have a clear span of 32 feet.
3.4.1 Civil
The horizontal alignment was intended to be designed as straight as possible to utilize a
temporary overhead skyway to provide access to the penstock alignment for construction
purposes. Vertical bends were minimized to reduce the number of anchor blocks.
The isolation valve is located in a valve vault, downstream of the diversion dam. The
penstock between the intake and valve vault will be encased in concrete to reduce the
possibility of leakage or pipe break and to allow any potential future improvements in this
area.
Three air vacuum valves have been designed along the alignment to protect the penstock in
case of a surge event. A Surge Analysis Report is included in Appendix E.
A blowoff is located at the low point in the penstock at the crossing of Reynolds creek to
drain the penstock for any needed maintenance.
3.4.2 Structural
1. The penstock design and construction shall be in accordance with the requirements
of ASCE Manual and Reports on Engineering Practice 79 “Steel Penstocks” and
AWWA Manual M11. The steel penstock calculations are included in Appendix F1.
The design calculations were completed with the following material, manufacturing,
and fabrication assumptions:
12 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
a. Penstock Pipe Material: Steel plate for the manufacture and fabrication of the
steel penstock pipe will be ASTM A1018 HSLAS, Grade 50, Class 2 or ASTM
A1018 HSLAS-F, Grade 50 meeting the physical and chemical properties of
ASTM A572, Grade 50.
b. Minimum specified yield strength 50,000 psi.
c. Minimum specified tensile strength: 60,000 psi.
2. Fabrication: All longitudinal and girth seams, whether straight or spiral, will be butt-
welded using an approved electric-fusion-weld process
3. Corrosion Protection: The steel penstock will be lined and coated with polyurethane.
Therefore, no corrosion allowance is required in thickness calculations.
4. Weld efficiencies: Weld efficiency factors are in accordance with Table 3-3 of ASCE
MOP 79, with the following exception:
a. Single full fillet lap joints without plug welds are allowed in the penstock for
internal design pressure of up to 300 psi. A seal weld will be used on the other
end to facilitate air testing the weld quality. The joint efficiency factor for this
weld was limited to 0.45.
The calculations for Penstock Anchors are included in Appendix F2.
3.4.3 Mechanical
The penstock component will not include mechanical design.
3.4.4 Electrical
The penstock component will not include electrical design.
3.5 Powerhouse
The powerhouse will be located in plan at the approximate location of the anadromous
barrier of Reynolds Creek. The powerhouse will sit on an excavated bench at elevation 111
feet above mean sea level, which is approximately 20 feet above the ordinary high water
mark of Reynolds Creek near the location of the powerhouse.
A 24 inch diameter bypass sleeve valve will be located in a concrete vault to bypass flows
around the powerhouse for turbine shutdowns and maintenance.
The powerhouse will be an insulated, pre-engineered metal building to be installed on a
concrete slab foundation. The powerhouse will contain one 5,000 kW horizontal impulse
turbine/generator set, flywheel, inlet piping, guard valve, switchgear, and controls.
Centerline of the turbine will be at approximately elevation 115 feet amsl. Space
requirements are approximately 40 feet by 60 feet.
Haida Energy, Inc. is currently in the process of soliciting bids for either a Turgo or Pelton
Turbine and anticipates a selection in the fall of 2010.
3.5.1 Civil
Approximately 500 feet of new access road will be required to access the powerhouse site.
The access road into the powerhouse site will be at a maximum slope of 12 percent. The
access road will be 20 feet wide and constructed of a granular fill base and a crushed rock
top course. Fill slopes will be 1.5 H to 1 V and cut slopes will be 1 H to 1 V.
Reynolds Creek Hydroelectric Project 13
Supporting Design Report August 2010
3.5.2 Structural
The powerhouse will consist of a prefabricated metal building and a reinforced concrete slab
and foundation. The criteria used for the structural design of the slab and foundation are
located in Section 4.0. The structural foundation for the powerhouse will be designed upon
the turbine selection, scheduled for the fall of 2010.
3.5.3 Mechanical
1. General Design Requirements
a. Rating: Nominal 5 MW
b. Flow range: Minimum flow achievable for stable operation (assumed to be 5 – 90
cfs)
c. The turbine will be a horizontal shaft impulse design with the turbine runner
directly coupled to an extended generator shaft. The flow operating range and
efficiency will be maximized by providing a multi-jet design.
d. The turbine-generator unit, accessories, and instrumentation will be capable of
continuous automatic control from the powerhouse or from a remote location.
The turbine can be started, synchronized and connected to the electrical system,
as well as loaded and stopped from both locations. The system controls allow
starting the unit in three ways: local, local-remote, and remote.
2. Manual startup of each subsystem.
a. Semi-automatic startup with manual synchronization.
b. One button automatic starting and loading.
c. Under normal operating conditions the turbine will be capable of unattended
operation.
3. The turbine will be designed for continuous operation at all points within the
performance envelope. The turbine will be capable of running at maximum power at
the maximum tailwater elevation of 105 feet (based on 90 cfs flow through the
turbine). The turbine selection will favor designs that can provide stable operation at
the lowest possible flow.
4. Routine maintenance will be possible without turbine shutdown and will not be
required more often than weekly. Preventive maintenance or inspection requiring
shutdown will not be required more frequently than annually.
5. The turbine will operate at the conditions specified in this document without
excessive cavitation or rough operation. Excessive cavitation is defined as a
condition which results in pitting of the turbine runner buckets with material as
defined in IEC 60609.
6. The turbine-generator and all auxiliary equipment will be utility grade designed for a
50-year operating life.
7. The design pressure for the turbine pressure parts will be not less than 1.50 times
the maximum static head and will be in accordance with ASME Boiler and Pressure
Code, Section VIII.
8. The equipment height will take into account a maximum powerhouse ceiling height of
22 feet.
14 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
9. A monorail hoist will be installed below the ceiling along the turbine-generator
centerline for runner removal and equipment maintenance.
10. The water used for power generation at this facility is glacial melt which contains
quantities of glacial flour, silt, and sand. Due to the erosive effects of this glacial flour,
silt and sand in the water, materials for the critical components of the turbine
including, runner buckets, needle valves, deflectors, turbine bypass valve and turbine
inlet valve will be selected to meet performance and durability requirements.
11. Technical Turbine Data
a. The turbine will be a Multi-Jet Shaft Horizontal Shaft Impulse turbine.
b. The unit will be specified to provide stable operation at all points within the
performance envelope shown below.
Table 1. Technical turbine performance envelope.
Net Head (ft)* Flow (cfs) Duration (Hrs/Yr)
760 <10 79
759 10-20 560
758 20-30 1130
756 30-40 1174
751 40-50 1016
750 50-60 894
746 60-70 753
741 70-80 666
736 80-90 552
730 >90 1936
c. Static head, ft - 784(ft) Allows for future elevation of normal forebay headpond
level.
d. Surge allowance on static head, % - 20% plus or minus
12. Housing
a. The horizontal turbine housing will be a ribbed design of welded steel
construction. The housing will be ribbed as necessary to provide proper rigidity.
The lower portion will be embedded in concrete. The turbine housing will be
equipped with:
i. Mounting feet.
ii. Anchor bolts.
iii. Lifting lugs.
b. Horizontal turbine housing will be a two piece design. The lower part imbedded
and the upper part removable.
c. Turbine housing wetted surfaces will be painted with coating suitable for severe
environments.
Reynolds Creek Hydroelectric Project 15
Supporting Design Report August 2010
13. Runner: The runner will be of high efficiency, with integral buckets, cast of erosion
resistant material and designed for minimum cavitation and erosion during normal
operation and to safely withstand stresses occurring at maximum runaway speed.
Consideration will be given to bolt-on bucket design if the water characteristics show
high erosion properties. The runner shall be made of ASTM A743 Grade CA 6NM
cast stainless steel or equivalent. The runner will be precision ground, polished, and
statically balanced. The runner will directly coupled to the generator shaft using a
solid flanged coupling..
a. A stress analysis of the runner utilizing three-dimensional finite-element modeling
techniques to verify that stresses and deflections that will occur under the most
severe operating conditions expected. The analysis, as a minimum, shall include
the following loading conditions:
i. Operation at maximum Net Head
ii. Operation at maximum overspeed.
b. The stress analysis shall verify that maximum tensile stresses expected under
normal operating conditions shall be less that 1/5 of the ultimate tensile strength
or 1/3 of the yield strength, whichever is lower, for the materials utilized.
Maximum tensile stresses expected at maximum overspeed shall be less than
1/4 of the ultimate tensile strength or 2/3 of the yield strength, whichever is lower,
for the materials utilized.
c. An analysis of the runner that will forecast the crack initiation and propagation
phases of fatigue life using:
i. Conservatively assumed crack geometry (e.g., edge crack along the
transition of the runner hub to bucket).
ii. The maximum local cyclic stresses evaluated superimposed on any residual
stresses that are introduced during the manufacturing process.
iii. Published fatigue properties and fatigue analyses of the proposed materials.
iv. The analyses shall demonstrate that there is sufficient margin in the runner
design to prevent initiation of new cracks in the high-stressed areas of each
constituent material which is subjected to the operation schedule of the units
as given below. The analyses shall also demonstrate that any pre-existing
flaws or cracks remaining after the proposed NDE examinations will not
propagate to a point of component fracture or to a degree which could
hamper machine operation or performance during the design life of the
runner. A minimum factor of safety of 2 shall be assumed to cover the
uncertainties involved in the fatigue and fracture model input parameters
thereby effectively raising the design life to 100 years.
14. Operating Schedule Assumptions as follows:
a. Operating cycle of start - power increase to efficiency load - stop, three (3) times
per day, seven (7) days per week.
b. Twelve (12) load rejections from Full Load (i.e., maximum output at Normal
Gross Head) per year.
15. Shafting System: The power developed by the runner will be transmitted to the
generator rotor through a forged steel shafting system. The shaft shall be
manufactured of ASTM A668, Class D forged steel or equivalent. The generator
shaft and turbine shaft will be bolted together via a solid flanged coupling with fitted
16 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
bolts. The coupling flanges will be forged integral with each shaft and fitted bolts will
be used to connect the coupling flanges together. The turbine shaft will be provided
with a hardened stainless steel sleeve at the shaft seal location.
a. A stress analysis of the existing turbine-generator shafting system will be
completed. The analysis will evaluate worse case operating conditions with the
new runner installed and shall verify that the maximum stresses due to torsion
combined with axial tension in the shafting system components shall be less than
6,000 psi. Purchaser will provide information about the existing shaft within
reason that may be required by Supplier to perform these analyses.
16. Nozzle: Each complete nozzle assembly will include:
a. A nozzle body, of welded or cast steel construction and flange connected to the
turbine housing. The nozzle body will be equipped with a removable self
lubricated guide bearing to support the needle stem, and replaceable packing or
seal to prevent water leakage around the needle stem.
b. One replaceable nozzle tip made of high strength steel resistant to cavitation and
erosion. One needle, with either a stainless steel needle stem or a high strength
carbon steel needle stem protected by chromium plating.
c. One hydraulic actuator for positioning of the nozzle.
17. One deflector of cast or fabricated stainless steel construction designed for extended
periods of operation partially deflected.
18. One double acting hydraulic servomotor for actuation of the deflector, and spring for
positive deflector closure. Other means of deflector emergency closure acceptable
are by means of a counterweight or a hydraulic pressure accumulator.
19. Four limit switches on the nozzle motor actuator and two limit switches on the
deflector servomotor.
20. A mechanical position indicator for nozzle and deflector for local position indication.
21. A position transmitter for all deflectors and needles.
22. Inlet Piping
a. The inlet piping will consist of:
i. Transition piece from 42 inch diameter steel penstock to inlet piping system
or bifurcation.
ii. Bifurcation to divide inlet piping into two sections for the two inlet nozzles.
iii. Turbine main shutoff valve.
iv. Erection/dismantling joint to allow valve removal for future maintenance.
v. Piping from shutoff valve to turbine inlet nozzles.
b. The inlet piping will be a carbon steel fabrication and an assembly of several
sections. Flanged ends will be provided for connection to the nozzle assemblies.
The inlet section will be supplied with an erection joint for connection to the inlet
valve. All flanges to be 300 pound (lb) ANSI. All bolts to be U.S. Standard. Inlet
piping general arrangement will conform to the powerhouse general arrangement
drawings (preliminary) attached to this specification. All valves will be located
inside the powerhouse building.
23. Nozzle and Deflector Operator
Reynolds Creek Hydroelectric Project 17
Supporting Design Report August 2010
a. A hydraulic nozzle positioning system will be included as part of the turbine
system to properly position the nozzles in response to signals provided by the
intake headpond level transmitter or plant control system.
b. The hydraulic power unit (HPU) will supply an oil pressure need to exceed 1000
p.s.i. static pressure to operate nozzles and deflectors.
c. Full stroke deflector may operate in the closed position for extended time
periods. Multi-jet deflectors are to be mechanically linked.
d. The system pressure will be controlled by adjustable pressure switches, which
will cover the following functions:
e. Lead/lag select switching for main and standby pumps.
f. Pump start and stop.
g. High and low pressure alarm.
h. Start condition and stop at critical low oil pressure.
i. Automatic start of standby pumps should the main pump fail.
j. The HPU will have a directly controlled full flow relief valve (routed back to the oil
sump) to prevent system damage in the event of control equipment failure.
k. A shutoff valve and flow control valves will be incorporated into the design.
l. The hydraulic pressure accumulator capacity will provide for two complete
strokes of the turbine inlet valve or the turbine needle valves, deflectors and
bypass valve, whichever is greater.
m. A hydraulic oil heater will be provided if required due to the powerhouse interior
design temperature range specified herein.
24. Runner Alignment
a. Means will be provided so that erector and plant maintenance mechanics can
find and obtain axial and radial alignment of the runner pitch circle with the
centerlines of the jets within 0.031 inches.
25. Turbine Design and Construction Features
a. Shaft seal:
i. A shaft seal will be provided where the shaft passes through the turbine
housing will be selected taking into account the erosive nature of the water.
ii. Any flush water required for seal operation will use the glacial melt from the
headpond. The shaft seal will be provided with the necessary equipment to
treat the seal flush water. This system must be able to operate maintenance
free for at least a week between maintenance intervals.
iii. Any water leakage through the shaft seal will be collected and conveyed to
an NPT termination and then piped to the tailrace pit.
b. Lubrication and hydraulic oil systems:
i. System to be designed to assure the use of a single type of lubricating oil for
all turbine, turbine inlet valves, turbine hydraulic pressure unit, and generator
oil systems.
18 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
c. Turbine (and generator) bearings will be designed to avoid use of external
cooling water. Air cooled circulating systems or self-cooled bearing oil reservoirs
are preferred to avoid use of river water for cooling. River water experiences
seasonal high turbidity which is expected to cause plugging problems if used for
cooling water.
d. Vibrator monitor: A continuous on-line vibration monitoring system for the
turbine/generator consisting of a two channel monitor for X-Y radial vibration
monitoring in the vicinity of the generator main bearing will be specified. Monitor
will have adjustable set point for alarm and shutdown trip points and vibration
amplitude readout in mils vibration.
26. Piping and Valves General:
a. All piping systems, valves, and fittings required for the turbine will be furnished
and arranged by Contractor. Valves and other operating devices will be easily
accessible, and gauges and other indicating devices will be located where they
can be conveniently read.
b. All piping materials, design, and installation will be in accordance with
ANSI/ASME B31.l - Power Piping.
c. The piping and piping materials will consist of all necessary water, oil and grease
piping together with associated strainers, valves, fittings, supports, anchors,
hangers, etc. required for complete operating systems for the equipment
specified.
d. The piping and piping materials to be furnished will be new and suitable for the
duty and the best of their respective kinds, and will be subject to acceptance by
Owner. Stainless steel tubing of appropriate design may be required
e. Piping 2-1/2 inches and larger in diameter will be shop fabricated, insofar as
practical for transportation and installation. Each fabricated pipe spool will be
uniquely identified both on the pipe and on the applicable piping installation
drawing. All sharp edges and weld spatter will be removed prior to coating.
Accessible internal welds will be reduced to a smooth contour by grinding.
Fabricated pipe sections requiring field fit-up will have a loose flange at one end
or extra material for field trimming and welding.
f. Arrangement of the piping and the locations of valves and joints will be such that
there will be a minimum disturbance of the piping and interference with other
service systems when the equipment is dismantled or parts removed for
inspection or repairs.
g. Long radius pipe fittings will be used in lieu of standard pipe fittings whenever
feasible to do so. Insulating flanges, couplings, bushings, or unions will be used
to join ferrous pipe with nonferrous pipe.
h. Oil piping will be thoroughly pickled, passivated, cleaned, oiled inside, and
painted outside with one coat of inorganic zinc primer and provided with wooden
flange protectors and capped or otherwise sealed at the ends before being
shipped. Stainless steel tubing will be swabbed clean and flushed but need not
be pickled.
i. Welding of branches, headers, bends, etc., will be done in the shop consistent
with the requirements for shipment and erection. Piping between fittings will not
be welded unless the piece to be fabricated is greater in length than the standard
Reynolds Creek Hydroelectric Project 19
Supporting Design Report August 2010
manufactured length of pipe. Any welds in the piping which cannot be visually
inspected on the inside of the pipe will be made with backing rings or
consumable inserts, in accordance with an accepted welding procedure.
j. Piping will be supported in accordance with B31.l code requirements and
standard practice. Hangers, supports, and guides will be such that the pipe is
maintained in alignment without sagging or excessive strain on the lines due to
uncontrolled movement under operating conditions. Piping will be arranged to
facilitate flushing, draining, and bleeding of the main lines. Air bleed valves will
be located at high points of the hydraulic system where necessary and drain
valves will be located at low points.
k. Piping will be installed in neat and orderly manner to result in a pleasing
appearance and not obstruct traffic patterns or maintenance in the powerhouse,
as determined by the Owner.
l. Welded joints of the same size pipe will be beveled and butt welded for piping 2-
1/2 inches and larger and socket welded for piping 2 inches and smaller.
m. Valves will be provided wherever necessary for operation of the system and for
maintenance.
n. All valves, except valves built in and forming an integral part of the governor or
pumping units, will have close guide clearances so as to minimize vibration of the
gates when operating under pressure and at partial opening. All gate valves, over
six-inch size installed in pressure lines, will be provided with standard bypasses
for equalizing pressures.
o. All pipe, valve seats, valves and heat exchangers in contact with water will have
materials resistant to corrosion and the erosive effects of glacial flour in the
water.
p. Following installation, all piping and tubing will be flushed with the service fluid
and filtered.
27. Turbine inlet valve:
a. The turbine will be furnished with a manually operated, flange connected turbine
inlet valves. The turbine inlet valves will be of 1/4 turn full port type. The valve
body will be fabricated steel, cast steel, or forged steel or a combination thereof.
All parts in contact with water will materials resistant to corrosion and the erosive
effects of sediment in the water. The valve operation will be fully open or closed,
throttling or positioning will not be required.
b. The turbine inlet valve size and design will be selected by the Contractor to
minimize head loss, maximize power generation, and minimize capital cost. The
valve will be flange connected to the bifurcation.
c. The turbine inlet valves and related accessories will be designed and
manufactured for operation under a pressure of 1.50 times the static head
specified herein.
d. The valve will be capable of closing against the static head with two (2) times the
maximum normal turbine flow under emergency conditions.
e. The turbine inlet valve will be complete with manual gear drive operator,
downstream dismantling joint, position indicators, full open and close limit
switches, soleplates and anchor bolts. A means of limiting the pressure rise in
20 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
the penstock to twenty-five percent above static head in the event that the valves
are manually closed as quickly as possible will be required.
28. Blowoff valves:
a. A body blowoff valve for removing sediment from the turbine inlet valve body,
and guard valve with all associated piping will be furnished. These valves will be
steel flanged, manually operated, and connected to a flange near the bottom of
the valve body.
b. Blowoff valves will be provided at the bottom of each movable seat ring control
water chamber to flush out sediment unless the moveable seat rings are
mounted on the disk. Guard valves will also be provided. The blowoff and guard
valves will not be less than 3/4 inch size, with forged steel bodies.
c. All necessary pipes, fittings, flanges, bolts and gaskets designed to withstand 1.5
times the maximum static head will be provided.
29. Turbine drain valve: A turbine drain valve and guard valve will be supplied connected
to the low point of each arm of the bifurcation (downstream of the turbine inlet valve)
and will discharge to the tailrace. The drain valve and guard valve will be steel
flanged, manually operated valves with all necessary pipe, fittings, flanges, bolts and
gaskets designed to withstand the maximum static head will be provided.
30. Air vent valve: A combination air relief and vacuum valve will be furnished and
installed at the highest point of the turbine nozzle supply pipe. The valve will function
as an air vent when the turbine distributor is filling and will function as a vacuum
breaker during dewatering the distributor.
31. Needle valves and deflectors:
a. The needle valves will incorporate double acting oil operated servomotors,
needles, springs, nozzle seat rings and jet deflectors, and will be directly flange
connected to the inlet bends and turbine housing.
b. The needle valves and deflectors will be hydraulically linked so that on partial or
full load rejection the jets are deflected in a short period of time. The needles will
close slowly and the deflectors will return to a position clear of the jets.
c. All necessary piping for connecting the turbine hydraulic pressure unit to the
regulating mechanism will be Contractor supplied.
d. The nozzle seat rings, needle tips and needle rods will be fabricated of materials
resistant to the erosive effects of sediment in the water.
e. The deflectors will be manufactured from material resistant to the erosive effects
of sediment in the water.
f. The needle valves and deployed deflectors will be capable of continuous
operation for 8 hour periods and a total of 160 hours per year at a flow equal to
the minimum power generation flow (speed no load flow plus 10 percent) of the
turbine-generator without suffering detrimental performance affects.
g. Solid-state, microprocessor-based, digital governor, electric-hydraulic type,
complete with components required to control the turbine shut-off valve, turbine
deflectors and needle valves. Governor will be capable of black start operation
using power from the station 125 volt DC battery system. Provisions will be
mode to allow for local, local-remote, and remote operation. During normal
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Supporting Design Report August 2010
operation, needle position will be controlled remotely by others. The governor will
contain displays showing needle valve position, deflector position, unit speed,
hydraulic system pressure, and generator load.
h. Jet deflector and turbine needle valve operation will be achieved by an oil-
hydraulic system specified in this section.
32. Load generation as a result of overspeed or operation of protective devices.
a. The hydraulic power unit will be sized to have the capacity to operate the inlet
valve simultaneous to needle and deflector operation.
33. Performance
a. Control System:
i. Capable of controlling the turbine, when operating isolated from the system,
at any speed between 85% and 105% of rated speed. Speed oscillation,
dead time and dead band will meet the requirements of IEEE Standard No.
125.
ii. Operates the jet deflectors through a full stroke in an adjustable range of 2 to
4 seconds, and operates the turbine needle valves in not less than 5 minutes
or more than 10 minutes.
iii. Includes selectable speed, power, and level control modes with built-in CPU
failure and loss of signal detection.
iv. When there is a failure the deflectors will completely deflect the jets and the
needles and inlet valve will fully close.
3.5.4 Electrical
1. Generator and Ancillary Equipment
a. Generator Type: The generator will be synchronous, horizontal shaft, driven by
an impulse turbine. It will be air cooled, guarded open machine enclosure with
integral fan cooling. The generator will be foot mounted.
b. Generator Rating: Based on hydrologic factors and system parameters known at
this time, the generator rating is presently established as follows:
i. Rated Capacity 5,000 kW
ii. Power Factor 0.80 or 0.90 (leading and lagging),
dependent on bid price
iii. Speed match turbine rpm
iv. Maximum Overspeed match/exceed turbine runaway speed
v. Max. Continuous Overspeed Period 1 hour in any 24-hr period
vi. Voltage 4,160 Volts
vii. Phases 3
viii. Frequency 60 Hertz
ix. Connection Wye
x. Rotation match turbine
xi. Insulation:
Stator Class F or better
Rotor Class F or better
22 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
Exciter Class F or better
xii. Stator Temperature Rise Class B
xiii. Rotor Temperature Rise Class B
xiv.Minimum Guaranteed Efficiency at Rated Speed and Load: 97.0 per cent or
better
xv. Mounting Foot mounted
xvi. Ambient Temperature Maximum 40 oC
2. Final Detailed Design - Generator characteristics will be selected to provide optimum
voltage control, regulation, and operational stability. Inertial capacity will be specified
as required for overspeed and hydraulic surge limitations and operational stability, in
conjunction with governor response and needle valve closure.
3. Fire Protection – A fire protection system will be provided for the generator. The
system will include cylinders for initial release and additional cylinders for delayed
release to provide extended protection in case of an internal fire. The fire protection
system will be automatically activated by selected generator fire protection and by
temperature sensing elements inside the generator air housing.
4. Generator Winding and Grounding Equipment – The generator will be connected.
The generator neutral will be connected to ground through a grounding transformer
with a resistor in the secondary of the transformer to limit internal single winding fault
currents and provide for ground fault protection.
5. Generator Protection –
a. The generator will be protected by the following electrical protection:
i. Voltage controlled overcurrent in each phase
ii. Differential
iii. Loss of field
iv. Reverse phase sequence
v. Overvoltage
vi. Neutral instantaneous overcurrent
b. Mechanical problems will also shut down the generator to protect it and its
systems from serious damage. The following mechanical functions will cause the
generator to shut down:
i. Bearing excess temperature
Turbine bearing(s)
Generator bearing(s)
Flywheel bearing
ii. Bearing low oil level
Turbine bearing(s)
Generator bearing(s)
Flywheel bearing
c. Fire Protection System Operation
d. Generator alarms will be initiated by the following functions:
i. Generator circuit breaker automatic trip
ii. Any bearing temperature high
Reynolds Creek Hydroelectric Project 23
Supporting Design Report August 2010
iii. Any bearing oil level high or low
iv. Fire protection discharged
v. Fire protection system off
vi. Generator winding temperature high
vii. Housing access door open
6. Brushless Exciter and Voltage Regulator – The brushless exciter system will be a
solid state exciter with automatic voltage regulator. The exciter will have both
manual and automatic control in the voltage regulator. Power for the exciter will be
supplied from a three-phase dry-type exciter transformer connected to the generator
bus on the generator side of the generator circuit breaker. The connection will be
made in the generator switchgear by means of medium voltage power cables.
7. A field flashing circuit will be provided from a separate DC source to initiate voltage
buildup for black-start capability. The exciter will have both over and under excitation
limiters.
8. The automatic and manual voltage regulators shall track together so that there will
be no voltage or reactive change when the regulator is switched from manual to
automatic or automatic to manual control.
9. The following devices will be used to cause the exciter to trip, resulting in generator
shutdown on loss of excitation:
a. Generator terminal over voltage
b. Excitation transformer high temperature
c. Rotating Rectifier failure
d. Rotating Rectifier temperature high
10. Generator Bus – The generator bus will be 5 kV copper bus capable of carrying at
least 115% of the rated generator current with applicable derating factors. The bus
will terminate in a metal-enclosed power terminal cabinet. NEMA standard 4-hole
pads will be provided for termination outgoing power cables and neutral cable.
11. Generator Switchgear – The generator switchgear will be 5 kV, indoor, metal-clad
switchgear and will be located in the powerhouse. The generator switchgear will
consist to of several cubicles as required to include the following equipment:
a. Drawout vacuum circuit breaker for the generator.
i. Surge arresters (3)
ii. Surge capacitors (3)
iii. Current transformers – Metering, protection, and voltage regulation.
iv. Potential transformers – Metering, protection, voltage regulation, and
synchronizing.
v. Connections to the Station service equipment
vi. Short circuit and arc flash studies will be performed on the electrical system
to check the electrical equipment size and ratings.
12. Neutral Grounding Equipment – The generator neutral will be grounded through a
distribution transformer with a secondary resistor load. A voltage relay will be used
across the resistor to measure and trip the generator for ground fault protection.
24 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
13. Station Service System – will include:
a. A fused 4.16 kV switch in the Generator Switchgear will power the station service
transformer.
b. Dry-type station service transformer with 4.16 kV, delta primary and a 480/277-V,
wye secondary side, three-phase, and rated to supply station service loads.
c. Station service motor control center is rated 480/277 V, 3-phase, 4-wire, with a
bus ampere rating to match the station service loads. All station service electric
power loads will be supplied from the station service motor control center.
Station service loads will include:
i. Hydraulic Pressure Unit
ii. Bridge Crane
iii. Lube Oil Unit
iv. HVAC equipment
v. Station air compressor
vi. 480/277 Volt, 3-phase power distribution panel board(s)
vii. 480-208/120- Volt, 3-phase, 60-Hertz dry type power and lighting
transformer(s)
viii. 208/120- Volt, 3-phase power and lighting distribution panelboard(s)
ix. Turbine shutoff valve
x. Sump pumps
xi. Other Balance of plant electrical equipment.
d. A 125 Volt DC station battery, battery charger, 125 Volt DC power panel and 120
Volt AC inverter will be provided. This equipment will be configured to provide a
field flashing circuit to allow black-start capability for the hydro generator.
e. For backup power service to the station service motor control center (MCC), the
MCC is equipped with a fully rated manual transfer switch with lug provisions to
connect feeder cables to a portable generator. In the event of major island power
grid failure simultaneous with failure of the 125 Volt DC station battery, the
Owner can temporarily connect a portable 480 Volt generator to the station
service MCC via the manual transfer switch. This will allow the Owner to black
start the hydro generator under this very unusual scenario.
14. Grounding System – A copper cable ground mat will be provided under the
powerhouse structure and tailrace. Risers for the ground mat will be extended up
through the foundation and powerhouse walls for grounding and bonding equipment
and exposed metal in the powerhouse. All exposed metal equipment and piping will
be solidly grounded and bonded to the ground mat. The copper cable will be
stranded, bare, soft annealed copper ground cable. Exposed cable fittings and
connections will be compression or thermoweld type. Connectors to electrical
equipment will be two-holed lugs. Ground rods will be copperclad steel, ¾-inch
diameter, and a minimum of 10 feet long.
15. Lighting System – powerhouse and fluorescent lighting will include low bay metal
halide fixtures. The lighting will be 208 and 120 Volt, single phase. Exterior lighting
will be wall mounted flood lights mounted on the powerhouse and walls. Emergency
and egress light fixtures will include battery backup. Ballasts will be electronic
energy efficient type.
Reynolds Creek Hydroelectric Project 25
Supporting Design Report August 2010
16. General receptacles will be duplex, 120 Volt, 20 Ampere. Receptacles will be
located where required. Receptacles in wet and exterior locations will be GFCI and
weatherproof. Special receptacles will be located and rated to provide power to
special equipment.
17. Raceway System – The raceway system will include conduit, trench, and trays.
Cable trays will be galvanized steel ladder type. Separate or divided trays will be
used to separate power from communication and instrumentation cables. Lighting
and receptacle conduits will be a minimum of ¾-inch diameter. In general conduit
will be exposed. Embedded conduit will be schedule 40 PVC or rigid galvanized
steel, where required. Device and outlet boxes will be galvanized cast steel. Pull
and termination boxes will be exposed, galvanized NEMA 12 rated minimum boxes,
sized to meet NEC requirements and specific requirements. Flexible and sealtite
flexible conduit will be used to connect to motors and equipment subject to vibration.
Sealtite conduit will be used where subject to moisture. Buried conduit will be
schedule 40 rigid plastic conduit except where subject to traffic or vehicles, then it
will be schedule 80.
18. Controls and Supervisory Controls –
a. Plant controls will be local manual control at the equipment, remote manual and
automatic at the powerhouse.
b. Balance of plant programmable logic controller (PLC) will be a General Electric
platform.
c. Communication between PLC(s), plant protection and control equipment shall be
via an Ethernet network.
d. Turbine governing will be accomplished with a dedicated General Electric PLC
for turbine governing with a Clifton Labs, Ltd. turbine governing program or
equal.
e. A plant control panel will be provided to house the PLC(s), auxiliary control
equipment, manual control switches, and human machine interface (HMI) touch
screen.
f. The plant SCADA system will be an Intellution system similar to the SCADA
package at AP&T Black Bear Lake power plant.
g. A fiber optic cable along the transmission line route will link Reynolds Creek to
Black Bear Lake or to the Craig Central office dependant on AP&T requirements.
19. Fire Detection and Alarm System – A fire detection and alarm system will be
provided in the powerhouse and will include smoke, ionization, and heat detection.
Alarms will be provided at the powerhouse and remotely to the AP&T central control
room.
20. Security System - An intrusion alarm system will be provided in the powerhouse.
Doors will be monitored by balanced magnetic switches. Access indication will be
sent back to the AP&T central control room via the powerhouse control system
computer. Smoke detectors will be provided in the powerhouse and heat detectors
will be provided near the hydro generator.
21. Generator Step-up Transformer –
a. The generating unit will have a dedicated generator step-up transformer to step
up power from the generator voltage, 4.16 kV to transmission voltage, 34.5 kV.
26 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
The transformer capacity will be rated such that the maximum generator capacity
will be the maximum rating of the transformer with forced air auxiliary cooling and
a rated temperature rise of 65oC. The transformer will be rated 4.16-34.5 kV,
5/7.5 MVA (ONAF-/FANA). The transformer basic impulse level (BIL) ratings will
be 250 kV BIL for the high side and 110 kV BIL at the low side. Manual operated
tap changers will be included with five taps, two 2.5 percent above and two 2.5
percent below nominal.
b. The generator step-up transformer will be located near the powerhouse to
minimize the 4.16 kV connections to the powerhouse. Oil containment and oil
separation structures will be provided for oil spill containment
3.6 Tailrace
3.6.1 Civil
A 54 inch diameter tailrace pipe will be used return project flows from the powerhouse back
to Reynolds Creek as close as possible to the existing anadromous fish barrier. The buried
and elevated steel pipe tailrace will extend about 400 feet from the powerhouse to Reynolds
Creek. Although the powerhouse site moved to the northwest, this tailrace discharge
location will remain at about a pool elevation of 90 fmsl approximately 50 feet downstream
of the existing anadromous fish barrier log jam and falls identified by the agencies.
The flow from the end of the tailrace pipe will free-fall discharge ten feet into a minimum
three foot deep (at low flow) rock lined plunge pool adjacent to the creek. The plunge pool
will be lined with rock placed so that any exposed edges are oriented so as to not injure fish.
This free discharge and plunge pool will serve to dissipate the energy and equilibrate
dissolved gasses to ambient levels before reaching the creek. The ten foot drop also will act
as a barrier to prevent fish migration into the tailrace pipe. The minimum three foot pool
depth will prevent injury of jumping fish while not being deep enough to allow fish to
accelerate for vertical jumps.
Water from the plunge pool will flow and diffuse back into the adjacent creek through a short
connecting channel.
Only the end of the tailrace discharge pipe will be near the normal Reynolds Creek stream
channel, therefore, most of the tailrace can be constructed at any time. The pier support for
the outlet end of the tailrace and the plunge pool excavated into flood plain will be
constructed during a low flow period so that the work can be conducted outside of the in-
water work window. The short channel section between the plunge pool and the stream
channel will need to be excavated during the in-water work window, which will be planned
for the second construction season. Since the excavation will be in cobbles rather than
bedrock, only one or two days work will be required, and no cofferdams or temporary
structures will be required.
3.6.2 Structural
The criteria used for the structural design of tailrace are located in Section 4.0.
3.6.3 Mechanical
The tailrace component will not include mechanical design.
3.6.4 Electrical
The tailrace component will not include electrical design.
Reynolds Creek Hydroelectric Project 27
Supporting Design Report August 2010
3.7 Transmission Line/Switchyard
The switchyard at the powerhouse will consist of:
A dead end structure for overhead transmission line conductors to connect to the generation
facility. This structure is where surge arresters, disconnect switches, and instrument
transformers are located.
A steel pedestal mounted circuit switcher with integral disconnect.
A pad mount step-up transformer with underground cables to the powerhouse for
connection to the switchgear generator breaker.
The overhead 34.5 kV transmission line will follow the access road from the powerhouse
and existing logging roads, along the edge of the Copper Harbor, and continue to the north
of Hetta Inlet.
Approximately 4.2 miles from the powerhouse, the transmission line would make an aerial
crossing of Hetta Inlet via Jumbo Island. The line would then follow the existing road to a
point approximately 0.45 miles northeast of the town of Hydaburg where it will connect with
an existing power line. Total length of the transmission line will be approximately 12.1 miles.
Except for the aerial crossing of Hetta Inlet, the poles would be designed single wood pole
structures with approximately 300 foot spans. Design of the line will also incorporate the
latest raptor protection guidelines. Collision avoidance devices may be installed on the line
at appropriate locations to protect migratory birds. Aerial Marker Balls will be installed at
Hetta Crossing as warning devices for seaplane operations.
3.7.1 Civil
Approximately 2,000 ft of additional access road spurs will be required to build 3 or 4 select
transmission line structures on the east side of the Hetta Inlet that can not be accessed by
the current logging roads.
3.7.2 Structural
The transmission line and switchyard will require a reinforced concrete platform. Section 4.0
contains the design criteria which will be used to design the reinforced concrete elements of
the transmission line and switchyard reinforced concrete platform.
3.7.3 Mechanical
1. NESC Loading Zone
a. This project is designed using the NESC Heavy loading zone.
2. Extreme Wind Condition
a. An extreme wind condition of 120 miles per hour (mph) or 36.9 psf has been
applied to all wires, guys, poles, equipment, and hardware.
b. NESC 2007 factors have been applied to account for height, wind funneling,
shape factors, drag coefficients, exposure effects, etc.
3. Extreme Ice with Concurrent Wind
a. A condition of 50 mph wind and 0.5 inch ice has been applied to all wires, guys,
poles, equipment, and hardware.
4. Safety Factors
28 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
a. All safety factors are for Grade B construction. The following RUS safety factors
have been applied in the design:
b. Overload Capacity Factors
NESC HEAVY EXTREME W & I
Vertical 1.50 1.10
Wind 2.50 1.10
Wire Tension 1.65 1.00
c. Strength Factors
NESC HEAVY EXTREME W & I
Wood Poles 0.65 0.75
Guys 0.90 0.90
Suspension Connectors 1.00 1.00
Deadend Connectors 1.00 0.80
5. Conductor Data:
a. Conductors used for typical design
i. Static wire: None
ii. 34.5 kV Conductors: 4/0 ACSR 6/1 Stranding “Penguin”
iii. Tension Limit = 30% Rated Strength Limit @ NESC HVY
iv. Neutral Conductor: 1/0 ACSR 6/1 Stranding “Raven”
v. Tension Limit = 30% Rated Strength Limit @ NESC HVY
vi. Communications: ADSS 24 pair
vii. Sag at 1.5% of RS sag at 60 deg F Initial
b. Conductors used for Hetta Inlet water crossing
i. Static wire: None
ii. 34.5 kV Conductors: 19 no. 8 Alumoweld
iii. Tension Limit = 35% Rated Strength Limit @ NESC HVY
iv. Neutral and Communication Conductor: Alumacore OPGW
v. Tension Limit = 35% Rated Strength Limit @ NESC HVY
6. Clearances:
a. Vertical clearances are based upon sags at the following conditions:
i. 34.5 kV conductors: 212°F, final
ii. 12.5 kV phase conductors: 167°F, final
iii. 12.5 kV neutral conductors: 120°F, final
iv. Comm. cable: 60°F, final
b. Ground Clearance:
i. The following table summarizes the minimum vertical ground clearance
requirements for this project:
Reynolds Creek Hydroelectric Project 29
Supporting Design Report August 2010
Table 2. Minimum vertical ground clearance requirements
7. Raptor Protection
a. 5 feet phase spacing between 34.5kV conductors is required for raptor
protection.
b. Ground wire will be run from neutral down to pole ground. Post insulator bases
will not be bonded to ground.
3.7.4 Electrical
The switchyard will be designed to interconnect with a new 34.5 kV transmission line that
will be tied to AP&T transmission grid. The switchyard will include:
1. One 3-phase, SF6 horizontal circuit switcher 34.5 kV nominal rating, 200kV BIL,
1200 Amperes continuous, 20 kA momentary symmetrical primary fault interrupting
capability. The circuit switchers will have 5 cycles interrupting time and rated for 30
full fault operations or better. The circuit switchers will be mounted on tubular steel
single mounting pedestal type support structures. Mounting pedestal height to be
specified.
2. 34.5 kV, 3-phase, gang operated, vertical break, 1200 Amperes continuous, 20,000
Amperes momentary air disconnect switches mounted on tubular steel pi type
support structures. Arcing horns will be provided.
3. Lightning arrestors to protect from transmission line surges.
4. Take-off structure (dead end) for tying to the 34.5 kV transmission line.
5. Potential transformers for monitoring line voltages.
NATURE OF SURFACE
UNDERNEATH WIRES,
CONDUCTORS, OR CABLES
RUS MINIMUM CLEARANCES (FT)
69 KV
12.5
KV NEUTRAL/COMM
Over agricultural lands 21.7 21 18
Over roads and driveways 21.7 21 18
Over other supporting structures 8.2 6.5 4
Over 13.2 kV distribution
conductors (same structures) 3.9 n/a n/a
Over 13.2 kV distribution
conductors (diff. structures)4.2 n/a n/a
Over communication wires (same
structures) 3.1 2.7 n/a
Over water areas not suitable for
sail boating 20.2 19.5 16.5
Over water areas suitable for sail
boating (over 200 to 2000 acres) 37.7 37 34
Pedestrian only areas 17.7 17 12
30 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
6. Grounding – the ground grid within the switchyard will be 4/0 copper. A 2/0 copper
ground wire shall be buried outside the fence perimeter, connecting to alternate
fence posts. Underground connections will be compression or thermoweld type.
7. Duct and Cable – Cable for control and power will be installed in schedule 40 rigid
plastic conduit concrete encased, and rigid galvanized steel for direct buried or
above ground locations. Multiconductor control cable will be used for control and
alarm functions between the switchyard equipment and the powerhouse.
8. Station Lighting – Outdoor lighting shall be provided, manually controlled from within
the powerhouse. Photo-control is not required.
9. Fencing – The switchyard area will be enclosed by a fence. A 20-foot wide vehicle
gate will be provided.
10. Yard Improvements – The switchyard area will be sterilized and covered with a
minimum of 6 inches of crushed rock.
11. Structures – The design of the switchyard will be low profile, utilizing steel structural
shapes for improved aesthetic appearance. No lattice type structures will be used.
The 34.5 kV dead end takeoff structure will be unguyed.
12. 34.5 kV protective relaying will be subject to coordination with AP&T transmission
system.
4.0 GENERAL STRUCTURAL ANALYSIS AND DESIGN
This section presents the general criteria to be used in the structural analysis of the features
for the Reynolds Creek Hydroelectric Project.
4.1 Codes, Standards, and References
4.1.1 Purpose
The purpose of this subsection is to identify the principal codes, standards and references to
be used in the design and construction of the Reynolds Creek Hydroelectric Project.
4.1.2 Codes and Standards
1. IBC 2006, International Building Code and referenced codes and standards
2. ASCE Manuals and Reports on Engineering Practice No. 79: Steel Penstocks
3. AWWA Manual M11, Steel Water Pipe: A Guide for Design and Installation
4. AISC 360-05, Specification for Structural Steel Buildings
5. ACI 318-05, Building Code Requirements for Structural Concrete and Commentary
6. ASCE/SEI 7-05, Minimum Design Loads for Buildings and Other Structures
7. AWS D1.1-04, Structural Welding Code – Steel
8. AISC Manual of Steel Construction, 13th edition.
9. ASCE/SEI 7-05, Minimum Design Loads for Buildings and Other Structures
10. FERC Dam Design Criteria
Reynolds Creek Hydroelectric Project 31
Supporting Design Report August 2010
4.2 Computer Programs
The computer programs that were utilized in the structural design and analysis associated
with this project includes, but not limited to, the following:
1. RISA 3D, a three-dimensional finite element program for structural analysis.
4.3 Materials
1. Structural Reinforced Cast-In-Place Concrete, unless otherwise indicated:
a. f’c = 3000 psi.
b. Ec = 57000*f’c^.5=3122 kips per square inch (ksi), (ACI 318-05, Section 8.5)
c. Cement - ASTM C150, Type II.
d. Pozzolan - ASTM C618. Class M. C, or F.
e. Grout - ANSI/ASTM C50.
f. Sand and Coarse Aggregate - ASNI/ASTM C33.
g. Curing Agent: ASTM C-309, Type 2
h. Water / Cement Ratio: 0.45 Maximum
i. Air Content: 6% 1% for all walls and pedestals. No air content required on
footings.
j. Reinforcing Steel: ASTM A-615, Grade 60 or ASTM A706 Grade 60 where
welding is required by the engineer.
k. Concrete Poisson Ratio = 0.15
2. Structural Steel properties of this project conform to the following criteria unless
otherwise noted on drawings or in the specifications:
a. Steel Modulus of Elasticity = 29,000 ksi
b. Poisson’s Ration = 0.3
c. Steel Unit Weight = 490 lb/ft³
d. Steel, Structural Shapes and Plate
i. All W-shapes and WT-shapes: ASTM A-992
ii. Provide ASTM A572, Grade 50 with special requirements per AISC Technical
Bulletin #3, and New Shape Material, dated March 3, 1997.
iii. ASTM A992 may be used in lieu of ASTM A572, Grade 50.
e. Plate and Flat Bar: ASTM A-36 or ASTM A-572, Gr 50
f. Pipe (other than penstock): ASTM A-53, Type E, Grade B
g. Penstock pipe: ASTM A1018 HSLAS, Grade 50, Class 2 or ASTM A1018
HSLAS-F, Grade 50 meeting the physical and chemical properties of ASTM
A572, Grade 50.
h. Hollow Structural Sections (HSS): ASTM A-500, Type B or C, Grade B
i. High Strength Bolts:
i. Galvanized
32 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
ii. ASTM A-325: Bearing type connections
j. High Strength Nuts
i. Galvanized
ii. ASTM A-563
k. High Strength Washers
i. Galvanized
ii. ASTM F-436 hardened washers (standard thickness or 5/16” thick if
pretensioned with OVS or SSL holes and bolt diameter > 1”)
l. General Anchor Rods
i. Galvanized
ii. Cast-in-Place: ASTM F-1554 Grade 36 or 55
iii. Post Installed: As specified in design drawings
m. Structural Column Anchor Rods
i. Galvanized
ii. ASTM F1554 Grade 36 or 55
n. Welding Electrodes
i. Weld Procedures per AWS D1.1 or AWS D14.1
ii. Weld Minimum strength, Fu = 70 ksi
4.4 Loads
There is limited information for the Hydaburg Alaska area; therefore we established the
design loads based on the minimum design requirements for the closest town City of Craig,
Alaska. Brian Templen, city planner for the city of Craig, provided minimum design
requirements for wind, seismic and snow loading.
The following loads were be used in the structural analysis of the project structures.
1. Dead Loads
a. Concrete Unit Weight: 150 lb/ft³
b. Steel Unit Weight: 490 lb/ft³
c. Masonry: 133 lb/ft³
d. Wood: 35 lb/ft³
e. Soil Unit Weight: Per Project Geotechnical Report
f. Actual Equipment Weight
2. Live Loads
a. Slabs on Grade: 300 lb/ft²
b. Operating Equipment and Floors: 300 lb/ft²
c. Walkway & Well Platform:
i. All Metal Gratings: 100 lb/ft²
d. Walkways, Platforms, and Stairs:
i. Non-Public Accessible (Operating) Areas:
Reynolds Creek Hydroelectric Project 33
Supporting Design Report August 2010
(1) Use same loadings as Public Accessible Areas but use OSHA
requirements as a minimum if needed.
(2) Stairs (& Platforms): 100 lb/ft²
(3) Handrails, guardrails, and posts: 200 lb point load in any direction,
applied at the top of each rail.
(4) Ladder: minimum design live load shall be a single concentrated load of
200 pounds
ii. Roof Loads: Per IBC Section 1607.11
3. Occupancy Category
a. Category III (Table 1-1, ASCE 7-05)
4. Snow Loads: Ground snow load requirements for nearby City of Craig is 50 psf
(provided by Brian Temple, City planner)
a. Ground snow load:
i. Facilities near power house: 60 psf.
ii. Facilities near Lake Mellen and Penstock: , Pg = 100 psf
b. Importance factor: 1.0
c. Exposure Factor, Ce (Terrain Category B, Sheltered): 1.2
d. Thermal factor: 1.2
5. Wind Loads: Wind load requirements were established based on information design
requirements for nearby City of Craig (provided by Brian Temple, City planner), as
follows:
a. F=qz*G*Cf*Af
b. Wind Category: C
c. Basic Wind Speed, V: 120 mph (ASCE 7 Fig. 6-1)
d. Iw: 1.15 (Importance Factor, ASCE 7 Table 6-1)
6. Seismic Loads: The seismic loading for the site facilities were determined based on
seismic hazard information published on the USGS and the code requirements on
2006 IBC, and the geotechnical recommendation contained in the geotechnical
report prepared by Shannon & Wilson (Sept, 2008):
a. Soil Class: B
b. Ss: 0.395
c. S1: 0.256
d. Fa: 1.0
e. Fv: 1.0
f. SDS: 0.263
g. SD1: 0.171
h. Seismic Design Category: B
7. Geotechnical design recommendations were obtained from the geotechnical report
(Shannon & Wilson, “Preliminary Geotechnical Report: Reynolds Creek Hydroelectric
Project, Hydaburg, Alaska”) included in Appendix A2 unless referenced otherwise:
34 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
a. Soil overburden:
i. Soil unit weight: 120 lb/ft³
ii. o (Assumed)
iii. c = 1 ksf (Assumed)
b. Allowable Bearing Pressure:
i. Qallow = 4000 lb/ft²
c. Frost Depth: 36”
d. Allowable Bond Stress for Rock Anchors: 100 psi
8. Crane Loads:
a. Crane Lift capacity required is 15 Tons
b. Impact loads for Bridge Crane per ASD-529
c. Lateral 20% perpendicular to movement
d. Vertical 10% perpendicular up and down
e. Longitudinal 10% Along the track
4.4.1 Structural Analysis
The following design approaches methods are to be used for the structural analysis and
design of the project elements, based on the material used: per the ASCE 7:
1. Strength Design (Load Factor): All concrete elements load combinations are in
accordance with ASCE 7.
2. Working Stress Design (ASD): Steel elements. Load combinations are in accordance
with ASCE 7. Load combinations for steel penstock design per ASCE MOP 79.
Where applicable on the project, the following serviceability criteria will be met under service
loading:
1. Walkway Deflection
4.4.2 Internal Loads in Penstock
Based on the proposed construction, the design full pool elevation (El 876) and the
powerhouse elevation (El 111), the maximum static head in the penstock pipe is 765 feet
(i.e., 332 psi). Considering a potential future raise of the dam to a crest elevation of 910, the
design of the penstock was completed for a maximum static head of 799 feet (i.e., 346 psi).
The following static head, surge allowances, and test pressures considered in the penstock
design are as follows:
1. Maximum static head: 799 ft (346 psi)
2. Surge allowance for normal surge conditions: 10% of steady state pressures
3. Surge allowance for emergency surge conditions: 60% of steady state pressures
4. Surge allowance for exceptional surge conditions: 175% of steady state pressures
5. Test pressure head: static pressure head + 24 feet.
4.4.3 Water Properties
1. Unit weight of water = 62.4 pcf
Reynolds Creek Hydroelectric Project 35
Supporting Design Report August 2010
2. Design water temperature = 40 degrees F
4.4.4 Air Temperature
1. There is no data available for the Hydaburg area.
2. The closest city that air temperature data was available for was Ketchikan and Corey
Banplt from the National Weather Service can be contacted at 907-790-6800
3. The maximum recorded temperature was 96 degrees F in Ketchikan on June
25,1913. Max. temperature possible was assumed to 100 degrees F.
4. The minimum recorded temperature was -8 degrees F in Ketchikan on January
24,1916. Min. temperature possible was assumed to -10 degrees F.
5. Penstock construction is expected to occur during summer months and the likely
temperature was assumed to vary from 50 to 90 degrees F. Therefore, the assumed
temperature differential range during penstock operation is -40 to 50 degrees F.
4.4.5 Foundation Design
Any completed and future foundation design on this project shall adhere to ASCE MOP 79,
2006 IBC, and the following criteria unless otherwise specified:
1. Sliding F.S. (due to lateral loads) shall be:
a. Normal pressure in-service conditions
b. Dynamic conditions, transient pressures resulting from load rejection
c. Seismic loading (DBC, as defined in ASCE MOP 79) combined with static
pressure
d. Extreme Conditions
2. Overturning F.S. (due to lateral loads) shall be:
a. Normal pressure in-service conditions
b. Dynamic conditions, transient pressures resulting from load rejection
c. Seismic loading (DBC, as defined in ASCE MOP 79) combined with static
pressure
d. Extreme Conditions
36 Reynolds Creek Hydroelectric Project
Supporting Design Report August 2010
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Appendix A1
Renshaw Geotechnical Report
Appendix A2
Shannon & Wilson Geotechnical Report
Preliminary Geotechnical Report
Reynolds Creek Hydroelectric Project
Hydaburg, Alaska
September 2008
Submitted To:
HDR Engineering, Inc.
500 108th Avenue, Suite 1200
Bellevue, WA 98004-5549
By:
Shannon & Wilson, Inc.
5430 Fairbanks Street, Suite 3
Anchorage, Alaska 99518
Phone: 907-561-2120
Fax: 907-561-4483
E-mail: klb@shanwil.com
Project Number: 32-1-01993-001
SHANNON & WILSON,INC.
PRELIMINARY GEOTECHNICAL REPORT September 2008
Reynolds Creek Hydroelectric Project, Hydaburg, Alaska Page i
HDR Engineering, Inc. 32-1-01993-001
TABLE OF CONTENTS
Page
1.0 INTRODUCTION.................................................................................................................1
2.0 PROJECT DESCRIPTION...................................................................................................1
3.0 LOCAL TOPOGRAPHY, CLIMATE, AND VEGETATION.............................................3
3.1 Topography ...............................................................................................................3
3.2 Climatology...............................................................................................................3
3.3 Seasonal Frost............................................................................................................3
3.4 Local Vegetation.......................................................................................................4
4.0 SITE DESCRIPTION............................................................................................................4
4.1 Rich’s Pond (Diversion Structure)............................................................................4
4.2 Penstock Corridor......................................................................................................5
4.3 Powerhouse Area.......................................................................................................5
4.4 Transmission Line Alignment...................................................................................5
4.4.1 Powerhouse to Jumbo Island ....................................................................5
4.4.2 Jumbo Island.............................................................................................6
4.4.3 Jumbo Island to Hydaburg........................................................................6
4.5 Access Roads and Quarry Sites.................................................................................6
5.0 REGIONAL GEOLOGY......................................................................................................7
5.1 Tectonics ...................................................................................................................8
5.2 Seismicity..................................................................................................................8
6.0 FIELD RECONNAISSANCE...............................................................................................8
7.0 SURFACE CONDITIONS....................................................................................................9
7.1 Rich’s Pond (Diversion Structure)..........................................................................10
7.2 Penstock Corridor....................................................................................................10
7.3 Powerhouse .............................................................................................................11
7.4 Transmission Line Alignment.................................................................................12
7.4.1 Powerhouse to Jumbo Island ..................................................................12
7.4.2 Jumbo Island...........................................................................................14
7.4.3 Jumbo Island to Hydaburg......................................................................14
7.5 Access Roads and Quarries.....................................................................................15
8.0 SEISMIC DESIGN CRITERIA..........................................................................................18
8.1 Peak Ground Acceleration.......................................................................................19
8.2 Seismically Induced Hazards ..................................................................................20
8.2.1 Liquefaction............................................................................................20
8.2.2 Ground Failure........................................................................................20
8.2.3 Ground Rupture ......................................................................................21
8.2.4 Tsunamis.................................................................................................21
9.0 PRELIMINARY ENGINEERING CONCLUSIONS.........................................................21
9.1 Diversion Dam and Intake.......................................................................................22
9.2 Penstock Alignment ................................................................................................23
9.3 Powerhouse .............................................................................................................24
9.4 Transmission Line Alignment.................................................................................26
9.4.1 Wooden Poles .........................................................................................26
9.4.2 Steel Towers ...........................................................................................27
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9.5 Access Roads...........................................................................................................27
9.5.1 Structural Section....................................................................................28
9.5.2 Embankment Development.....................................................................28
9.5.3 Access Road Repair................................................................................29
9.6 Quarry Development...............................................................................................30
9.7 Rock Blasting..........................................................................................................30
9.8 Rock Anchors..........................................................................................................31
9.9 Quarry Generated Material......................................................................................32
9.10 Fill Placement and Compaction ..............................................................................32
10.0 CLOSURE AND LIMITATIONS ......................................................................................32
LIST OF TABLES
Table 1 Field Reconnaissance Notes – Dam, Penstock, and Powerhouse
Table 2 Field Reconnaissance Notes – Powerhouse to Jumbo Island
Table 3 Field Reconnaissance Notes – Jumbo Island to Hydaburg
Table 4 Field Reconnaissance Notes – Powerhouse to Lake Mellen Access Roads
LIST OF FIGURES
Figure 1 Vicinity Map
Figure 2 Overview Map
Figure 3 Reconnaissance Map – Powerhouse and Dam
Figure 4 Reconnaissance Map – Lake Mellen and Copper Harbor
(GPS Points RC34-RC68)
Figure 5 Reconnaissance Map – Copper Harbor to Jumbo Island
(GPS Points RC68-RC77)
Figure 6 Reconnaissance Map – Jumbo Island (GPS Points RC01-RC09 & RC74-RC79)
Figure 7 Reconnaissance Map – Jumbo Island to Hydaburg (GPS Points RC01-RC15)
Figure 8 Reconnaissance Map – Jumbo Island to Hydaburg (GPS Points RC15-RC27)
Figure 9 Reconnaissance Map – Jumbo Island to Hydaburg (GPS Points RC26-RC33)
Figure 10 Seismicity Map
Figure 11 Gradation Requirements
LIST OF APPENDICES
Appendix A Photo Pages
Appendix B Prior Explorations
Appendix C Important Information About Your Geotechnical/Environmental Report
SHANNON & WILSON, INC.
PRELIMINARY GEOTECHNICAL REPORT September 2008
Reynolds Creek Hydroelectric Project, Hydaburg, Alaska Page 1
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PRELIMINARY GEOTECHNICAL REPORT
REYNOLDS CREEK HYDROELECTRIC PROJECT
HYDABURG,ALASKA
1.0 INTRODUCTION
This report presents the results of geotechnical surface reconnaissance conducted by Shannon &
Wilson, Inc. for the Reynolds Creek Hydroelectric Project on Prince of Wales Island near
Hydaburg, Alaska. The project includes the development of a dam, penstock, powerhouse, and
an approximately 11-mile long transmission line which will connect the new electrical works to
existing power infrastructure near the City of Hydaburg. At the time of our site visit, the exact
locations of the project structures and the alignment had not been finalized. The purpose of this
study was to visit the various portions of the project and observe the general site conditions,
including soil and rock exposures visible on the surface. The observations made during our
reconnaissance are intended to be used by the design team in developing preliminary, conceptual
design of the project features, and in feasibility studies. Presented in this report is a description
of our reconnaissance efforts, field observations made during reconnaissance, and engineering
conclusions regarding the further development of the project.
Authorization to proceed with this work was received in the form of a signed Subconsultant
Agreement from Mr. Duane Hippe of HDR Alaska, Inc. (HDR), on June 18, 2008. Our work
was conducted in general accordance with a scope of work described in our June 9, 2008
proposal.
2.0 PROJECT DESCRIPTION
Based on our conversations and the information you provided we understand that the overall
project consists of designing and constructing a new diversion dam and intake at the outlet of
Rich’s Pond below Lake Mellen, a bypass pipe, a steel penstock, a 5 megawatt (MW)
powerhouse, access roads, and an overhead 34.5 kV transmission line. The project is located on
Prince of Wales Island approximately 10 miles east of Hydaburg, Alaska, as shown on Figure 1.
Figure 2 presents a project location overview map covering the approximately 12-mile long
corridor and the project elements discussed below. According to the Craig A-2 USGS
quadrangle map, dam, penstock, and powerhouse portions of the project lie within Township 77
South, Range 85E, Sections 3 and 4, Copper River Meridian.
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The new diversion dam will be constructed at the outlet of Rich’s Pond, in the general area
shown on Figure 3, where the valley narrows and the stream gradient begins to steepen as it exits
the pond. The diversion structure will comprise grouted rip-rap and a concrete core cutoff wall
with a crest height of approximately 876 feet above mean sea level bringing the surface elevation
of the water in Rich’s Pond up to the approximate elevation of Lake Mellen. During periods of
extreme high water, water will be allowed to spill uncontrolled over the crest of the dam. A
concrete, box-type intake structure, which will serve to funnel water into the penstock will be
constructed on the south side of the diversion structure. Uninterrupted flow through the
diversion structure will be accomplished through construction of a 12-inch diameter bypass pipe
which will pass through the center of the structure.
The penstock will consist of an approximately 3,200-foot long, 42-inch diameter, epoxy coated,
welded steel pipe capable of providing a flow rate up to 90 cubic feet per second (cfs) to the
turbines housed in the powerhouse building below. Figure 4 shows the general penstock
alignment considered in this report. The penstock will be supported above-ground on simple
saddle supports constructed approximately 40 feet on-center. About 500 feet upstream of the
powerhouse, the penstock will cross over Reynolds Creek from the south side to the north side.
The penstock will span about 40 to 50 feet at this point and be supported on a concrete
foundation constructed on each end of the span.
A powerhouse structure will be constructed on the north side of Reynolds Creek just below the
creek crossing of the existing logging road in the general area indicated on Figure 3. According
to the concept design, the powerhouse will consist of an insulated, pre-engineered metal building
with dimensions of 60 feet long by 40 feet wide resting on a concrete slab foundation. The
powerhouse will contain one, 5 Megawatt, horizontal impulse, turbine/generator, flywheel, inlet
piping, guard valve, switchgear, and controls. A short, rip-rap lined tailrace channel will return
the diverted water back to Reynolds Creek.
A 34.5 kilovolt (kV), overhead transmission line will carry electricity approximately 10.9 miles
from the powerhouse to the tie-in with existing utility lines about 1.4 miles northeast of
Hydaburg along the general corridor shown on Figures 5 through 9. The overland line would
consist of 50 to 60-foot high, wood pole structures spaced approximately every 300 feet along
the alignment. The line will follow existing logging roads over most of its length except for a
proposed aerial crossing of Hetta Inlet near Jumbo Island. An aerial crossing would likely
require spans up to 1,000 feet in length and use Jumbo Island as a carry over location.
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Roads will need to be constructed to access the diversion structure and powerhouse sites. In
addition, several miles of existing roads on the east side of Hetta Inlet will need to be improved
and maintained to provide access for construction and maintenance equipment. According to the
project description provided by HDR it is estimated that less than 500 feet of new road will be
needed to reach the structures near the diversion dam and power house. The roads will be
constructed in a fashion similar to the existing logging roads in the area which appear to have
been cut and/or blasted into the hillsides and surfaced with crushed rock from quarry sites along
the roads.
3.0 LOCAL TOPOGRAPHY, CLIMATE, AND VEGETATION
3.1 Topography
The localized topography consists of steep mountain slopes separated primarily by u-shaped,
glacially carved valleys. Secondary, stream cut valleys typically run down through the bottoms
of these primary valley elements draining the rain and snowmelt from the higher elevations.
The shoreline varies from beach type deposits of sand and gravel to bedrock. Altitudes in the
project vicinity vary from sea level to near 4,000 feet (1,220 meters). Figure 2 presents pertinent
geologic and geographic site features of the project area.
3.2 Climatology
Prince of Wales Island has a maritime climate including high humidity and high precipitation.
On average, precipitation amounts to about 110 inches per year including over 30 inches of
snowfall. Snowfall varies with elevation across Prince of Wales Island and where snow falls at
lower elevations around the coastline, it is apt to be “washed away” by subsequent rainfall as the
temperature moves above the freezing level. Temperature variations near sea level on Prince of
Wales Island are tempered by the water surrounding the island. Summer temperatures vary from
about 43 degrees Fahrenheit (°F) to 66°F. Winter temperatures vary from about 23°F to about
39°F. Temperatures can be significantly cooler during the winter months at elevations higher
than 100 to 200 feet above sea level.
3.3 Seasonal Frost
With wintertime temperatures hovering around the freezing level there is typically little frost
penetration into the surface in undisturbed areas near sea level. Frost penetration will vary with
location, elevation, and subsurface conditions. Frost will likely penetrate most deeply at higher
elevations and beneath unheated building structures or beneath well-drained road surfaces that
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are kept clear of snow and particularly around large diameter drainage structures that allow cold
air to circulate beneath the ground surface (i.e. drainage culverts). Frost penetrations may also
be greater in shot rock or rip-rap fills with high air voids. We believe that over the various
portions of this project, frost may penetrate into the subsurface between 6 inches and 3 feet.
3.4 Local Vegetation
With its moderate temperatures and abundant humidity and precipitation, Prince of Wales Island
supports lush vegetation, dense forest growth, and muskeg or bog environment in low-lying
areas. The majority of the ground surface within the project limits is covered with a substantial
organic mat that consists of low growing ferns, moss, and muskeg. The forest is made up of
Sitka Spruce and Western Hemlock with some Western Red and Yellow Cedar, Alder, Willow
and Shore Pine. Logging operations have altered the natural habitat and vegetation in localized
areas throughout the island. These areas tend to be littered with downed trees covered by dense,
secondary growth of brushy and shrubby plant life.
4.0 SITE DESCRIPTION
For the purposes of this report, we have broken the project into sections that are defined by the
specific project element (ie. diversion structure, powerhouse, etc.) or, for the transmission line
alignment, into similar topographic regions and landforms that likely have similar subsurface
conditions. It is important to note that, although the subdivisions described in this report are
generalized and that even though a dominant soil condition or trend was observed in each region,
the soils do vary within each discrete area, sometimes significantly. The location and general
site description for each subdivision is presented below and actual subsection locations can be
viewed on the reconnaissance maps in Figures 3 through 9. Specific surface conditions are
included later in the Section 7.0.
4.1 Rich’s Pond (Diversion Structure)
Rich’s Pond is a small sub-basin immediately west of Lake Mellen and is interconnected with
Lake Mellen via a 200-foot section of low gradient stream that constitutes the outlet of the lake
(see Figure 3). The pond is bounded by small, steep sided hills covered with moss, willow,
spruce, and small muskeg areas on benches in the terrain. The outlet of the pond appears to
serve as the outlet for the entire drainage basin, including Lake Mellen, Summit Lake, and Lake
Marge. The diversion structure will be located in the outlet stream (Reynolds Creek) which exits
the west end of Rich’s Pond. Slopes in this area are steep and strewn with boulders, especially in
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and near the narrow outlet valley. Logging roads have been established that access Lake Mellen
from Copper Harbor.
4.2 Penstock Corridor
The penstock corridor is defined as the area between the diversion dam and the powerhouse site
as shown on Figure 4. According to conceptual plans the penstock will run down the mountain
side on the south side of Reynolds Creek and descends approximately 760 feet over its length.
Most of the terrain along the corridor is steep, uneven and strewn with boulders and rock
outcrops. Much of the lower portion of the corridor has been partially logged and is covered
with dense, secondary brush growth and downed trees that have not been removed.
4.3 Powerhouse Area
The powerhouse area consists of the area immediately to the west of the existing logging road
and bridge which crosses over Reynolds Creek as shown on Figure 3. The creek is bounded on
both sides by hilly terrain. On the north side of Reynolds Creek, near the location indicated by
the design team and on conceptual drawings, the creek has cut a 20 to 30-foot high bench into
the till soils that are exposed in the road cut above and are partially exposed on the bench itself.
An abandoned stream channel strewn with boulders and heavily overgrown with trees and brush
exists between the bench and the present course of Reynolds Creek.
4.4 Transmission Line Alignment
The transmission line alignment traverses approximately 10.9 miles from the powerhouse site
near Copper Harbor to Hydaburg paralleling existing logging roads for much of its length. The
alignment also crosses Hetta Inlet and will reportedly do so via an aerial crossing near Jumbo
Island. Site descriptions along for the transmission line have been divided into subsections for
this report based on geographic position.
4.4.1 Powerhouse to Jumbo Island
This section of alignment is shown on Figures 4 and 5 and travels adjacent to existing logging
roads approximately 3.3 miles from the powerhouse to the Hetta Inlet crossing near Jumbo
Island. The alignment generally traverses the steep south and southwest facing slopes of Copper
Mountain along Copper Harbor and Hetta Inlet. The slopes along this portion of the alignment
have been logged and are generally brush covered with sporadic stands of forested areas
remaining. Several rock quarries have been established along the existing roadways in the
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central portion of this alignment. The existing and proposed alignments also cross several
drainage features along this portion of the corridor. Road cuts expose areas of cobbly/bouldery
till and colluvium as well as bedrock.
4.4.2 Jumbo Island
Jumbo Island is a densely forested, approximately 100-acre island in the northern portion of
Hetta Inlet. As shown on Figure 5, the island is approximately 1,700 feet wide and 2,600 feet
long has a maximum elevation of about 200 feet according to USGS quad maps. Hetta Inlet is
approximately 4,000 wide at Jumbo Island. Most of the shoreline around the island consists of
exposed bedrock with occasional cobbly beaches in the coves.
4.4.3 Jumbo Island to Hydaburg
West of Hetta Inlet, the transmission line travels approximately 6.8 miles along a maintained
logging road where it will tie into existing overhead utility lines near Hydaburg (see Figures 7
through 9). Over the first 1/3 of the road from Jumbo Island the road largely traverses steep,
south facing slopes along Deer Bay. It then transitions into rolling terrain with alternating
forested and small muskeg covered areas over the next 1/3 of the route. The final 1/3 of the route
traverses steep, heavily forested, north facing slopes until the tie-in location. Till, alluvium,
colluvium soils and bedrock are exposed in many of the road cuts. Several quarries have been
developed along the road throughout this route.
4.5 Access Roads and Quarry Sites
Existing logging roads will likely be utilized for access and construction of this project. Much of
the existing infrastructure on Prince of Wales Island consists of a network of gravel logging
roads that were constructed more than 40 years ago in support of the Prince of Wales Island
logging industry. Some of the roads in the Copper Harbor area were constructed as recently as
1997. While the roadways adequately met the needs of the logging industry at the time, many
have not been improved or maintained to provide continuous access to all areas. In addition, we
anticipate that new roadways will likely be needed to access the diversion dam and power house
sites which are not immediately adjacent to existing roadways. A new access road may also be
needed that traverses Jumbo Island along the transmission line corridor.
Except for the portion from Hydaburg to Deer Bay/Jumbo Island, the logging roads in the project
area are unmaintained and will likely require repair and maintenance before, during, and after
construction of the project. These roads generally traverse the steep slopes through the
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mountainous terrain and have been developed to support the heavy equipment used for logging
operations. Culverts and bridge crossings are still in place over much of the roadway, although
some are damaged and may need repair depending on the type of construction and maintenance
equipment that will be used for this project. Rockfalls, landslides and tension cracks are also
present in some locations along the roads that will need to be accessed by construction
equipment. These hazards are a continuous occurrence in this type of topography and will
require constant monitoring and upkeep.
Rock quarries have been developed sporadically along much of the logging road system as a
source of crushed rock and fill material. We have attempted to locate these quarries during the
reconnaissance and have noted their existence in the field notes in Tables 1 through 4 and on the
reconnaissance maps.
5.0 REGIONAL GEOLOGY
The geology near the project area is dominated by rocks of the Craig Subterrane of the
Alexander Terrane. The Alexander Terrane spans the entire Alaskan Panhandle from the
southern end of Prince of Wales Island north to Haines, Alaska. The Craig Subterrane consists
of a variety of rock types that range from stratified, mafic metavolcanics and felsic intrusives
that range in age from Precambrian to Jurassic. The oldest recognized rocks (and the
predominant rock types found throughout the project area aside from the cretaceous intrusives)
in this assemblage are arc-type metasedimentary and metavolcanic rocks that are recognized as
part of the Wales Group. These rocks are generally lightly metamorphosed and do not usually
show strong foliation planes. Isolated areas of felsic intrusive rocks, such as granite and
granodiorite, are also present throughout the Alaska Panhandle, particularly along the eastern
margin of Prince of Wales Island. These intrusives are typically Cretaceous age rocks emplaced
around 102 ±3 million years ago. Locally, hornfels is also found within the contact aureoles
between the plutonic intrusions and host rocks of the Craig Subterrane.
In more recent geologic history, glaciers advanced over the area leaving drift deposits that
generally consist of till and other glacially deposited material. Not much is known about the
glacial history of this area, but these soils are believed to have been deposited during the last
glacial advance nearly 30,000 years ago. Typically, glacial drift (or till) has relatively equal
fractions of silt, sand, and gravel, along with some cobble- and boulder-sized particles. These
soils are usually very dense as they were loaded by nearly 3,000 feet of ice during previous
glaciation events. In general, experience shows that this soil is thickest in the flatter, lower
elevations and decreases in thickness in the higher, steeper terrain. Recent Quaternary deposits
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include thin layers of reworked expansive glacial drift, stream alluvium adjacent to major
drainages, colluvium, and muskeg in low-lying basins.
5.1 Tectonics
Located on the Circum-Pacific Earthquake Belt, the project area is subject to a relatively high
potential for earthquake activity and an intricate network of reverse, normal and strike-slip faults
dissects Southeastern Alaska. To the west, the area is truncated at the North American
continental margin by the Queen Charlotte-Fairweather fault system. This system is known to be
an “active” right-lateral fault with large displacements. The location of this fault, which
represents the plate boundary between North America and the Pacific Plate, is approximately 60
to 70 miles southwest of Hydaburg. Two other major fault systems, the Clarence Strait and
Chatham Strait Faults run approximately north-south along the eastern shore and to the west of
Prince of Wales Island, respectively. The Clarence Strait system is a left-lateral strike slip fault.
It is believed to have approximately 9 miles of displacement. The Chatham Strait fault, which
was active in the Tertiary Period (2 to 65 million years ago), is believed to have offset rocks as
much as 95 miles. This fault truncates in the south at the Queen Charlotte-Fairweather fault.
Many other smaller faults and shear zones splay off from these major features and have been
mapped or inferred throughout the region.
5.2 Seismicity
Several earthquakes with a magnitude of greater than 4.0 have occurred in the vicinity of Prince
of Wales Island, most are believed to be along the Queen Charlotte-Fairweather Fault System
west of the project area. Large earthquakes in the region include the August 21, 1949, Queen
Charlotte Islands and July 30, 1972, Sitka events. The Queen Charlotte Islands are just south of
Prince of Wales Island, the August 1949 event at this site registered magnitude 8.1. The Sitka
event in July 1972 registered magnitude 7.6 and was approximately 160 miles northwest of
Hydaburg. A seismicity map showing the general location of faults and earthquake activity
around Prince of Wales Island is shown in Figure 10.
6.0 FIELD RECONNAISSANCE
Our field reconnaissance included aerial observations, peat probing, and surface observations
over the project area and the transmission line alignment. The effort took place between June 24
and 27, 2008, and was conducted by Anchorage-based staff: Mr. Kyle Brennan, P.E., a
geotechnical engineer, and Mr. Ryan Collins, a geologist. Mr. Brennan attended a preliminary
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aerial reconnaissance of the area on the east side of Hetta Inlet on June 23, 2008 with the HDR
design team using helicopter support provided by Temsco Helicopters from Ketchikan, Alaska.
Our field team later accessed this area by skiff operated by a local resident from Hydaburg. In
general, the diversion dam, penstock, powerhouse, and transmission line alignment on the east
side of Hetta Inlet were accessed on foot. The transmission line alignment from Deer Bay/
Jumbo Island to the Hydaburg tie-in was accessed by vehicle. We made observations throughout
the project area at discrete locations that we recorded using a handheld Global Positioning
System (GPS) unit. Points RC52 and RC53 along the penstock corridor were approximated
using a barometric altimeter due to poor GPS coverage beneath a dense tree canopy. The notes
recorded during our reconnaissance are summarized in Tables 1 through 4 and selected
photographs are included on the photo pages in Appendix A, Figures A-1 through A-28.
Approximate locations of the observation stations are plotted on the reconnaissance maps
included as Figures 3 through 9.
The goal of the surface reconnaissance was to observe the general surface conditions at various
stations across the project area in order to evaluate geotechnical aspects that should be
considered before final design and construction of the project. The reconnaissance focused on
observing the general topography, vegetation, soil and rock exposures, peat/organic soil depths,
and existing rock quarries. Performing a surface reconnaissance also allows us to identify “red-
flag” areas with regard to design and construction while also affording us an opportunity to
observe the site in preparation for planning future subsurface explorations. Probing was
conducted with ½-inch outer diameter (OD) probes. The probes comprised four, 5-foot lengths
that could be connected together to form one 20-foot long probe. Probes were advanced until
they could not be pushed further by hand.
7.0 SURFACE CONDITIONS
Ground surface conditions observed during our reconnaissance include ground cover/vegetation,
peat/organic soil depths (as measured by peat probes), and soil and bedrock exposures. The
sections below describe the general ground surface conditions at specific locations across the
project area. A geotechnical investigation of the diversion structure and powerhouse site was
conducted by Dan Renshaw, P.E. of Anchorage, Alaska between September 1996 and May 1997.
This work is included with this report in Appendix B and in the form of boring logs (diversion
structure site) and a May 22, 1997 report titled Subsurface Investigation of the Reynolds Creek
Hydropower Project Located on Prince of Wales Island, Alaska, Phase II Powerhouse Site. The
results of these previous studies were considered in the discussions below as appropriate. Note
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that the conditions outlined in the sections below are generalized and that localized areas that
vary from these generalizations may exist.
7.1 Rich’s Pond (Diversion Structure)
Shannon & Wilson visited the approximate location of the proposed diversion structure area at
Rich’s Pond along the south side of Reynolds Creek on June 25, 2008. This area is included in
our field notes as GPS Points RC50 and RC51 and shown on the reconnaissance map in Figure
3. Tabulated field notes from each point are included in Table 1 and select photographs from
this area are included in Photo Page A-1 and on the corresponding reconnaissance map.
The area is situated in a narrow, steep sided canyon at the outlet of Rich’s Pond. We observed a
ground surface obscured by a 2 to 4-foot thick organic mat based on peat probing around the
vicinity. Judging by the steepness of the slopes we believe that the general ground conditions
consist of this organic mat overlying bedrock and/or boulders. The slopes and creek bed appear
to be littered with boulders, especially as the canyon narrows towards Reynolds Creek.
A subsurface investigation of the diversion area was conducted between September 9 through
13, 1996 by Mr. Dan Renshaw, Consulting Engineer, Anchorage, Alaska. Boring logs for this
investigation are included in Appendix B. This investigation consisted of four diamond drill
holes named Drill Holes S1, S2, N1, and N2 drilled at an angle to depths ranging from 21 to 45
feet bgs. In general the drill holes encountered 16 to 24 feet of “loose rocks and voids”
overlying granite and altered quartz diorite bedrock. Drill hole S1 did not encounter the loose
rocks or voids that were encountered by the other holes. Rock quality designation (RQD) ranged
between 58 and 99 percent, excluding a low value of 36 percent in one core length recovered
from Drill Hole S2.
7.2 Penstock Corridor
The proposed penstock corridor runs along the south side of Reynolds Creek between the
diversion dam and the powerhouse. The penstock will begin at the diversion dam at an elevation
of approximately 876 feet mean sea level (msl) and end at the powerhouse along Reynolds Creek
at around elevation 116 feet msl. We traveled this corridor by foot on June 25, 2008. This area
is included in our field notes as GPS Points RC52 and RC57 and shown on the reconnaissance
map in Figure 4. Tabulated field notes from each point are included in Table 1 and select
photographs from this area are included in Photo Pages A-1 through A-3 and on the
corresponding reconnaissance map.
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In general we observed a steep and uneven, west facing slope which appears to be at least
partially covered with boulders. Due to the steepness of the terrain, it is likely that these
boulders have sloughed from above in the active erosional processes. The corridor is densely
forested and the ground surface is obscured by brush and 1 to 3 feet of moss. Based on limited
exposure and observations of active landslides in the area, if boulders exist along the penstock
alignment, they could be as large as 8 to 10 feet in diameter or larger. From Point RC54 to Point
RC 57 near the Reynolds Creek bridge crossing, the area around the route is partially logged and
downed trees and dense brush growth further obscure the ground surface. Because of the limited
visibility of the ground surface, it is difficult to be certain about the presence of boulders and, if
they exist, what their distribution is along the slope. A landslide/rockslide originating from cliffs
and a steep mountainside to the south of the proposed route is visible around Point RC55.
Approximately 600 feet upstream of the bridge crossing the slope transitions to a shallower pitch
as smaller, secondary drainage features flow into Reynolds Creek.
7.3 Powerhouse
The proposed powerhouse is situated on the north side of Reynolds Creek, downstream of the
existing access road and bridge crossing. Although the exact location of the structure and site
features had not been determined at the time of our visit, two separate possible locations were
pointed out in the field by HDR design team members. These sites were visited by Shannon &
Wilson and HDR on June 23, 2008 and by our recon team again on June 26, 2008. The area is
included in our field notes as GPS points RC58 and RC59 and shown on the reconnaissance map
in Figure 3. Tabulated field notes from each point are included in Table 1 and select
photographs from this area are included in Photo Pages A-3 and A-4.
GPS Point RC58 is located at a potential powerhouse site located on a brush covered bench
approximately 30 feet above Reynolds Creek. The bench site is moderately to steeply sloped
except near the lip and appears to have been carved into the hillside by erosion from Reynolds
Creek. Based on probes and observation of the soil exposure in the road cut above, and
subsurface information outlined below, we believe that the ground conditions generally consist
of 1 to 5 feet of moss/organic overburden and 5 to 17 feet of till overlying marble bedrock.
GPS Point RC59 was recorded at an alternate location for the powerhouse. This area is in the
abandoned stream channel at the base of the bench due south of RC58. The area is densely
forested and brush covered. The ground surface, though obscured by 1 to 2 feet of moss, appears
to consist of boulder and cobble type, high energy stream deposits. Based on the general
subsurface conditions encountered by Mr. Renshaw, it is likely that the creek bed (and the
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Reynolds Creek Hydroelectric Project, Hydaburg, Alaska Page 12
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proposed powerhouse site) lies directly on bedrock at this location. Given its proximity to the
stream, there could be isolated pockets of alluvium soils over bedrock, but judging from
topography, if these soils are present, they are likely less than 5 feet thick.
A subsurface investigation of the powerhouse area was conducted by Mr. Dan Renshaw,
Consulting Engineer, Anchorage, Alaska sometime prior to the geotechnical report which was
submitted on May 22, 1997 (see Appendix B). This investigation consisted of four auger and
diamond drill holes named Drill Holes 1, 2, 3, and 4 which were drilled to depths ranging from 7
to 37 feet bgs. In general the drill holes comprised 1 to 4.5 feet of “organic surface loam with
rocks”, 5.5 to 17 feet of poorly cemented conglomerate, and marble bedrock. Drill Holes 1 and 2
which were advanced to 7.5 and 7 feet bgs, respectively, did not penetrate marble. It is our
opinion that the conglomerate is likely a densely compacted till similar to the material exposed
in the road cut above the proposed powerhouse site. The marble varied from black to gray and
white, massive, with few indications of faulting or jointing, and had an approximated RQD in
excess of 90 percent.
7.4 Transmission Line Alignment
Surface conditions along the transmission line have been divided into subsections based on
major geographic divisions (ie. powerhouse to Jumbo Island, etc.) similar to Section 4.0. These
subdivisions are further divided by soil conditions and significant variations in terrain for this
section. Alignment maps and photo pages for the transmission line alignment are included in
Figures 4 through 9 and Appendix A, Figures A-8 through A-28, respectively. Tabulated field
notes from each point are included in Tables 2 and 3.
7.4.1 Powerhouse to Jumbo Island
This portion of the transmission line alignment was traversed by foot on June 26, 2008. We have
broken this portion of the alignment into the four subsections below based on estimated
subsurface conditions and/or topography. The area is included in Table 2 as GPS Points RC34
through RC38 and RC60 through RC77 and shown on the reconnaissance maps in Figures 4 and
5. Select photographs from this area are included in Photo Pages A-8 through A-15
GPS Points RC34 through RC38
Surface conditions general consist of moderately steep, lightly forested, and brushy slopes within
a logged area. Soil and rock exposures in the road cuts along this stretch suggest that the
subsurface generally consists of 1 to 6 feet of till and colluvium overlying bedrock. In general,
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Reynolds Creek Hydroelectric Project, Hydaburg, Alaska Page 13
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the ground surface is likely covered with a mossy organic map approximately 1 to 3 feet in thick.
The predominant rock type between Points RC37 and RC39 observed in road cut exposure was
gray and white, massive marble. Exposures of rock from Points RC34 to RC39 were limited and
the rock type is assumed to consist of similar marble. An approximately 20-foot high roadcut
near Point RC38 exposes a sharp, nearly vertical contact where the north side exposes marble
bedrock while the south portion of the cut exposes a till. Several small drainages cross the
alignment in this section.
GPS Points RC60 through RC64
Surface conditions generally consist of steep, lightly forested, and brushy slopes within a logged
area. Soil exposures in the road cuts along this stretch suggest that the subsurface generally
consists of 1 to 3 feet of organic soils and moss over 2 to 20-plus feet of till and colluvium. No
bedrock was observed in the roadcuts in this portion until just west of Point RC64. A large
landslide which traveled nearly to the waters edge crosses the alignment at Point RC60.
Another, smaller slide which just crests the road surface crosses to the west of Point RC64.
Bedrock is exposed at some locations along the sliding surface of the landslide.
GPS Points RC64 through RC76
Surface conditions generally consist of steep, lightly to moderately forested, and brushy slopes
within alternating logged and unlogged areas. Soil and rock exposures in road cuts suggest that
the subsurface generally consists of 1 to 3 feet of organic soils and moss over bedrock. Several
quarries have been established along this portion of the alignment. The access road exhibits
sporadic tension cracks which are discussed in further detail in Section 7.5.
The dominant bedrock exposed along this portion of the alignment consists of slightly to
moderately weathered, foliated to massive, gray-green schists and phyllites. Around Point RC74
moderately to highly weathered, dark gray schist which has weathered almost to the consistency
of soil is exposed. Gray and white, banded marble and weathered dark gray schist is exposed in
a steep streamcut near point RC76.
GPS Point RC77 to Hetta Inlet
GPS Point RC77 was recorded at the bridge crossing of Jumbo Creek. The terrain slopes more
gently from here down toward Hetta Inlet and Jumbo Island. Surface conditions generally
consist of moderately sloping, forested and brushy slopes within alternating logged and unlogged
areas. The channel of Jumbo Creek is littered with boulders but some areas of the creek bottom
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Reynolds Creek Hydroelectric Project, Hydaburg, Alaska Page 14
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near the crossing may expose bedrock. Due to the lack of road cuts and stream exposures it is
difficult to estimate the subsurface conditions but it is likely that till and alluvial soils may be
thicker over this portion of the alignment. Marble bedrock is exposed along the shoreline of
Hetta Inlet and in a cut made near the end of the access road.
7.4.2 Jumbo Island
Jumbo Island is the site of the proposed aerial crossing of Hetta Inlet. We circled the island in a
skiff on June 26, 2008. The observations made at Jumbo Island are included in Table 2 as GPS
Points RC78 and RC79 and shown on the reconnaissance map in Figure 6. Select photographs
from this area are included in Photo Page A-16.
From the shore, Jumbo Island appears to be heavily forested with a ground surface obscured by
moss growth. Although we did not access the island on foot, visual observations of the coastline
reveal very little, if any, mineral soil horizon overlying bedrock. The coastline is comprises
bedrock cliffs with a few cobble-strewn beaches. The rock type could not be determined from
the skiff due to its dark, weathered rind but geologic maps indicate that it is of similar type to the
gray-green schist encountered at other locations along the alignment.
7.4.3 Jumbo Island to Hydaburg
This portion of the transmission line alignment was traversed by vehicle on June 24, 2008. We
have broken this portion of the alignment into the three subsections below based on estimated
subsurface conditions and/or topography. Note that the conditions outlined in the sections below
are generalized and that localized areas that vary from these generalizations may exist. The area
is included in Table 3 as GPS Points RC01 through RC33 and shown on the reconnaissance
maps in Figures 7 through 9. Select photographs from this area are included in Photo Pages A-
17 through A-28
GPS Points RC01 through RC15
Surface conditions generally consist of moderately steep to steep, lightly forested, and brushy
slopes within alternating logged and unlogged areas. The thickness of till or mineral soils was
unable to be determined in these areas through surface reconnaissance due to limited cut slope
exposures. Soil and rock exposures in the road cuts along this stretch suggest that the subsurface
generally consists of a 1 to 2-foot organic mat and 1 to 10 feet of till and overlying bedrock. The
estimated thickness of till soils in the area around RC08 may be as much as 15 feet. Two areas
where conditions vary from the general condition are around RC03 and near the mouth of a
Field Reconnaissance NotesPage 1 of 2Table 1SHANNON & WILSON, INC.Diversion Dam and Intake AreaGPSPoint #Site DescriptionNear outlet of pond approx. 20 feet above water. Steep side slopes. Access road would have to be higher on the hillside.Vegetation:SpruceGround Surface: 2 to 4-foot organic mat.Subsurface:Organics over bedrock.Near westernmost location of proposed dam. Steep slope with bench approx. 30 feet above creek.Vegetation:Spruce.Ground Surface: 2 to 4 feet peat based on probes.Subsurface:Organics over bedrock. Penstock RouteGPSPoint #Site DescriptionAlong penstock route. Bouldery with little to no soil. Steep canyon slopes at least 60 feet high on south side of Reynolds Creek.Vegetation:Spruce.Ground Surface: Moss.Subsurface:Moss over boulders. Boulder strewn area ends at rock face/cliff towards the west.Vegetation:Spruce.Ground Surface: Moss.Subsurface:Moss over boulders. Steep area along route. Area has been selectively logged but most of the trees were not removed. Rocky beneath moss mat.Vegetation: Spruce. Logged.Ground Surface: Moss.Subsurface: Moss over rock or boulders. Maybe thin soil mantle. Steep, rocky area near the toe of a recent rock slide. Lots of downed trees.Vegetation: Spruce. Logged.Ground Surface: Moss.Subsurface: Moss over rock or boulders. Maybe thin soil mantle. Slope angles flatter than upstream areas. No logging in this area.Vegetation: Spruce. Ground Surface: Moss.Subsurface: Moss over rock. Maybe thin soil mantle. Penstock route near road crossing. Lots of cut trees laying on the ground. Ground looks bouldery.Vegetation: Spruce. Logged.Ground Surface: Moss.Subsurface: Moss over boulders or rock.Photo CD RC56_A thru CPhoto CD RC57_A thru DPhoto CD RC52_A thru DPhoto CD RC53_A thru FPhoto CD RC54_A thru DPhoto CD RC55_A thru EPhoto ReferencePhoto CD RC50_A thru EPhoto CD RC51_A thru CPhoto ReferenceRC56RC57Photo 6Fig. A-3RC55Photo 4Fig. A-2RC54Photo 3Fig. A-2RC52RC53Photo 2Fig. A-1RC50Photo 1Fig. A-1RC51Preliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 2 of 2Table 1SHANNON & WILSON, INC.Powerhouse AreaGPSPoint #Site DescriptionPotential powerhouse site in cleared spot on a bench above Reynolds Creek. Bench is approx. 30 feet above creek elevation. No soil or rock is exposed on bench but a slide area exposing glacial till is above this location.Vegetation: Berry bushes and spruce.Ground Surface: Moss.Subsurface: 1 to 4 feet of peat/moss over glacial till based on probes.Another potential powerhouse location on river bank below the bench at RC58. Ground is uneven with lots of deadfall and appears to be strewn with boulders. From here, the bench at RC58 looks like a river terrace and is probably composed of glacial till over rock.Vegetation:Spruce, ferns, berries.Ground Surface: Moss.Subsurface:Moss over rock and/or boulders. Photo CD RC59_A thru DPhoto ReferencePhoto CD RC58_A thru ERC58Photo 5Fig. A-3RC59Photo 7Fig. A-4Preliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 1 of 4Table 2SHANNON & WILSON, INC.Transmission Line - Powerhouse to Jumbo IslandGPSPoint #Site DescriptionAccess road just above transmission line junction. Road is in good shape. Drainage crosses road through culvert.Vegetation: Birch and alder. Logged.Ground Surface: 1 to 2 feet thick organic mat.Subsurface:<2 feet of glacial till over bedrock.Access road at bridge crossing. Bridge is steel frame with timber deck. Road cut on uphill side exposes approx. 2 to 6 feet of glacial till over bedrock. Bedrock is also exposed in the creek bottom.Vegetation: Birch and alder. Logged.Ground Surface: 1 to 3 feet thick organic mat.Subsurface:2 to 6 feet of glacial till over bedrock.Stream crossing with steel frame and timber deck bridge. Rock exposed in creek bottom and in nearby road cut.Vegetation:Spruce and alder. LoggedGround Surface: 1 to 3 feet thick organic mat.Subsurface:1 to 6 feet of glacial till over bedrock.Access road. Rock cut approx. 20 feet high above road. Close access to powerhouse location.Vegetation:Spruce and alder. LoggedGround Surface: 1 to 3 feet thick organic mat.Subsurface:2 to 4 feet of glacial till over bedrock. Rock type: banded, gray and white marble.Access road above powerhouse site. Approx. 20 high road cut above road exposes bedrock and glacial till. 15 to 20 feet of glacial till is exposed. glacial till is exposed in slide below road also.Vegetation:Spruce and alder. LoggedGround Surface: 1 to 3 feet thick organic mat.Subsurface: 1 to >20 feet of glacial till over bedrock.Access road and bridge over Reynolds Creek. Bridge is steel framed with a timber deck.Vegetation: n/aGround Surface: n/aSubsurface: n/aLandslide crossing road. Between here and intersection (near RC34), road is in good condition with no obvious signs of distress. Road cuts on uphill side of road are typically 4 feet high and overgrown so soil/rock exposure is poor. Based on slide debris and cuts it looks like there may be several feet of glacial till over the bedrock here.Vegetation: Spruce and alder.Ground Surface: 1 to 3 feet of moss.Subsurface: Moss over 2 to 8 feet of glacial till.Road is in good shape but overgrown. Road cut on north side of road exposes at least 6 feet of glacial till.Vegetation: Alder.Ground Surface: 1 to 3 feet of moss/peat.Subsurface: 1 to >6 feet of glacial till.RC60Photo 18Fig. A-9RC61RC38Photo 15Fig. A-8RC39Photo 8Fig. A-9RC36RC37RC34Photo 17Fig. A-9RC35Photo 16Fig. A-8Photo ReferencePhoto CD RC34_A thru DPhoto CD RC35_A thru CPhoto CD RC36_A thru EPhoto CD RC37_A thru EPhoto CD RC38_A thru EPhoto CD RC39_A thru EPhoto CD RC60_A thru GPhoto CD RC61_A thru CPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 2 of 4Table 2SHANNON & WILSON, INC.Transmission Line - Powerhouse to Jumbo IslandGPSPoint #Site DescriptionRoad cut approx. 30 feet high, appears to be glacial till. Some soils debris in road from raveling of the cut.Vegetation: Alder. Ground Surface: 1 to 3 feet of organic mat.Subsurface: Possibly >30 feet of glacial till? Approx. 20-foot high road cut on the north side of the road exposing glacial till and bouldery debris. Boulders and debris in road from sloughing of slope.Vegetation: Alder.Ground Surface: 1 to 2 feet of organic mat.Subsurface: Moss over 20+ feet of glacial till.Same glacial till exposures in road cuts on north side of road. Cut is approx. 20 feet high. Boulders and debris on road surface. Overgrowth opens up a little. Rock outcrops to west of small slide on the west end of the road cut. Slide covers the road surface but does not travel much further downslope.Vegetation: Spruce and alder.Ground Surface: 1 to 3 feet of organic mat.Subsurface: Organics over 20+ feet of glacial till.Rock appearing in upslope cuts between here and RC64. Tension crack approx. 50 feet long along south 1/3 of roadbed.Vegetation: Spruce and alder.Ground Surface: 1 to 2 feet of organic mat/moss.Subsurface: Moss over rock. Maybe thin soil mantle. Rock type: gray-green schist.Rock exposed above road. Steep south facing slopes, unlogged. Tension cracks take up 1/2 to 1/3 of road and approx. 50 feet long.Vegetation: Spruce and alder.Ground Surface: 1 to 3 feet of moss.Subsurface: Moss over rock. Rock type: tightly folded, gray-green schist. Foliation planes (dip,dip direction) 25°, 240°; 45°, 230°.Turn corner on the road. It runs roughly north-south now. Rock is exposed on slope. Orientation of foliation planes roughly match the existing slope and could make this area more prone to slides and rock slope failures.Vegetation: Alder.Ground Surface: 1 to 3 feet of moss/peat.Subsurface: Moss over rock. Rock type same as RC66; foliation planes (dip, dip direction) 38°, 240°Quarry site. Quarry face is approx. 35 to 40 feet tall. Slopes are less steep between here and about 200 north of RC67. Debris in floor of quarry up to 3 feet in diameter.Vegetation: Alder and spruce.Ground Surface: 1 to 3 feet of moss.Subsurface: Moss over rock. No significant changes in rock type.Tension cracks take up 1/2 to 1/3 of road and approx. 50 feet long.Vegetation: Alder and spruce.Ground Surface: 1 to 3 feet of moss.Subsurface: Moss over rock. No significant changes in rock type.RC68RC69Photo 24Fig. A-12RC66Photo 22Fig. A-11RC67RC64Photo 19Fig. A-10RC65Photo 21Fig. A-11RC62Photo 20Fig. A-10RC63Photo ReferencePhoto CD RC62_A thru EPhoto CD RC63_A thru DPhoto CD RC64_A thru DPhoto CD RC65_A thru DPhoto CD RC66_A thru DPhoto CD RC67_A thru EPhoto CD RC68_A thru EPhoto CD RC69_A thru CPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 3 of 4Table 2SHANNON & WILSON, INC.Transmission Line - Powerhouse to Jumbo IslandGPSPoint #Site DescriptionSlough/slump in roadbed about half of road width. Rock exposed on hillside.Vegetation: Alder and spruce.Ground Surface: 1 to 3 feet of moss.Subsurface: Moss over gray-green schist. No significant changes in rock type.Quarry site. Debris up to 8 feet in diameter. Sporadic, discontinuous tension cracks in the nearby road surface.Vegetation: Spruce and alder.Ground Surface: 1 to 2 feet of organic mat/moss.Subsurface: Moss over rock. Same general rock type but with more massive structure.Tension cracks in west 1/3 of road and approx. 40 feet long.Vegetation: Spruce and alder.Ground Surface: 1 to 2 feet of organic mat/moss.Subsurface: Moss over rock. Foliation is stronger and near vertical.High point along road before it begins to go downhill towards the north.Vegetation: Spruce and alder.Ground Surface: 1 to 2 feet of organic mat/moss.Subsurface: Moss over rock. No significant changes in rock type; foliation plane (dip, dip direction) 45°, 190°Washout area and sporadic tension cracks about 500 feet to the south. Soil exposed in road cut looks like glacial till but is mostly colluvium and cut actually exposes highly weathered rock.Vegetation: Spruce.Ground Surface: 1 to 3 feet of organic mat/moss.Subsurface: Moss over 1 to 3 feet of glacial till and weathered bedrock. Rock type: highly weathered (almost to soil-like but still showsstructure), dark gray schist.Quarry site.Vegetation: Spruce.Ground Surface: 1 to 3 feet of organic mat/moss.Subsurface: Moss over 1 to 3 feet of glacial till and weathered bedrock. Rock type: massive to foliated, gray-green schist/phyllite.Washout on and across road. Rock is exposed in uphill stream cut.Vegetation: Spruce.Ground Surface: 1 to 2 feet of organic mat/moss.Subsurface: 1 to 2 feet of glacial till over rock. Rock types: banded dark gray and white marble; highly weathered, dark gray schist. Location may mark fault/shear zone.Log bridge over Jumbo Creek. Terrain slopes more gently from here to Jumbo Island along the road. Creek bottom is boulder covered and glacial till soils may be thicker in this area.Vegetation: Alder and spruce.Ground Surface: 1 to 3 feet of moss.Subsurface: Moss over glacial till and/or rock? RC76Photo 29Fig. A-15RC77Photo 30Fig. A-15RC74Photo 28Fig. A-14RC75Photo 27Fig. A-14RC72RC73Photo 25Fig. A-13, Photo 31Fig. A-16RC70Photo 23Fig. A-12RC71Photo 26Fig. A-13Photo ReferencePhoto CD RC70_A thru DPhoto CD RC71_A thru EPhoto CD RC72_A thru FPhoto CD RC73_A thru DPhoto CD RC74_A thru EPhoto CD RC75_A thru DPhoto CD RC76_A thru EPhoto CD RC77_A thru FPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 4 of 4Table 2SHANNON & WILSON, INC.Transmission Line - Powerhouse to Jumbo IslandGPSPoint #Site DescriptionEast side of Jumbo Island. No mineral soil.Vegetation: Spruce.Ground Surface: 1 to 2 feet of organics/moss.Subsurface: Moss over rock.West side of Jumbo Island. No mineral soil.Vegetation: Spruce.Ground Surface: 1 to 3 feet of organics/moss.Subsurface: Moss over rock.RC78Photo 32Fig. A-16RC79Photo ReferencePhoto CD RC78_A thru EPhoto CD RC79_A thru GPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 1 of 5Table 3SHANNON & WILSON, INC.Transmission Line - Jumbo Island/Deer Bay to Hydaburg Tie-inGPSPoint #Site DescriptionBeginning of transmission line on Hydaburg side. Traversing around toe of slope approx. 100 feet above water.Vegetation:Alders, spruce, partially logged.Ground Surface:Moss and shallow organics.Subsurface:Appears to have shallow rock. Rock is exposed in road cut. Rock Type: gray-green schist; foliation plane (dip, dip direction)32°, 175°.Quarry site along road.Vegetation:Conditions similar to location at Point RC01Ground Surface:Conditions similar to location at Point RC01Subsurface:Conditions similar to location at Point RC01Topography flattens. Conditions persist to approx. 200 feet east of Point RC04Vegetation:Alders and spruce Ground Surface:MuskegSubsurface:2 to 4 feet of peat/soft soils based on peat probingQuarry with ponded water in bottom. Transition to sloping terrain (slopes down toward south).Vegetation:Alders, spruce, partially loggedGround Surface:Thin organic mat and mossSubsurface:>2 feet of peat and till soil over rock. Rock type is same as found at Point RC01Sloping ground. Terrain is less severe, but soil and rock are exposed on uphill side of the road cut. Appear to be isolated areas of thicker soil overburden between RC04 and this location (up to 10 feet thick)Vegetation:Alders, spruce, partially loggedGround Surface:1 to 2 feet thick organic matSubsurface:1 to 10 feet of till over bedrock. Rock type: Metagraywacke, phyllite to schist.Bottom of drainage and rock face (approx. 20 to 25 feet high). Upslope cut transitions between alternating till and rock to thin soil mantle over rock towards the west.Vegetation:Spruce.Ground Surface: 1 to 2 feet thick organic mat/moss.Subsurface:<1 to 2 feet of till over bedrock. Rock type: dark gray, vuggy, graphitic schist.West side of drainage at RC06. Terrain slopes to south. Till soils thicker (approx. 5 to 10 feet). Rock is sheared and weak looking.Vegetation:Spruce.Ground Surface: 1 to 2 feet thick organic mat/moss.Subsurface:5 to 10 feet of till over bedrock. Rock type is same as found at RC06 but sheared, weathered, and weaker.High spot in road with 15 foot high cut bank exposing till. Bedrock is exposed in ditch at bottom of cut.Vegetation:Alders, spruce.Ground Surface: 1 to 2 feet thick organic mat/moss.Subsurface:Up to 15 feet of till over bedrock.RC07Photo 38Fig. A-19RC08Photo 39Fig. A-20RC05Photo 36Fig. A-18RC06Photo 37Fig. A-19RC03Photo 35Fig. A-18RC04RC01Photo 33Fig. A-17RC02Photo 34Fig. A-17Photo ReferencePhoto CD RC01_A thru FPhoto CD RC02_A and BPhoto CD RC03_A thru CPhoto CD RC04_A thru CPhoto CD RC05_A thru GPhoto CD RC06_A thru EPhoto CD RC07_A thru EPhoto CD RC08_A thru GPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 2 of 5Table 3SHANNON & WILSON, INC.Transmission Line - Jumbo Island/Deer Bay to Hydaburg Tie-inGPSPoint #Site DescriptionQuarry site. Face is approx. 30 to 40 feet tall and irregular. Material piled up ranges from sand to 2 to 3 foot diameter boulders.Vegetation:Alders and spruceGround Surface: 1 to 2 feet thick vegetation mat/moss.Subsurface:Generally bedrock with minimal till mantle starting 400 feet east of location.--Rock Type: Gray-green phyllite and dark gray, weak to medium strong, weakly foliated, graphitic schist; foliation plane (dip-dip, direction) 20°, 290°.Quarry site. Overgrown. Face is approx. 20 to 25 feet high. Areas with thin till mantle over rock.Vegetation:Birch, spruce, and alders.Ground Surface:2 to 3 feet organic mat.Subsurface:2 to 8 feet of till over bedrock. Rock is generally stronger than at RC09. Type: Gray-green, massive phyllite with quartz andpyrite mineralization.Topography flattens. Conditions persist to approx. 200 feet west of RC10Vegetation:Alders and spruce Ground Surface:Peat/muskegSubsurface:2 to 6 feet of peat/soft soil over till/rock based on peat probing. No local soil or rock exposures.Stream crossing. Bedrock exposed in stream bottom (not obvious) approx. 4 to 6 feet below road.Vegetation:Alders, spruce, birch.Ground Surface:2 to 6 feet of peatSubsurface:2 to 6 feet of peat over till/rock.Transition back into sloping terrain (downward toward the south). Pockets of till approx. 4 feet thick in uphill road cut.Vegetation:Alder and spruce.Ground Surface:1 to 2 feet thick organic matSubsurface:up to 4 feet of till over bedrock. Rock type: gray-green, tuffaceous (?) phyllite or greenschist.Quarry site. Face approx. 40 feet high. Several feet of till overburden without much organics.Vegetation:Spruce and alder.Ground Surface: 1 to 2 feet thick organic mat/moss.Subsurface:2 to 6 feet of till over bedrock. Rock type: gray-green, tuffaceous (?) phyllite or greenschist.Stream crossing exposing approx. 8 feet of till over bedrock.Vegetation:Spruce and alder. Logged area.Ground Surface: 1 to 2 feet thick organic mat/moss.Subsurface:2 to 8 feet of till over bedrock. Rock type is same as found at RC14.Sloped terrain. Slope transition (downward toward north, high side of road is on south). Road crosses south flowing drainage that has been beaver dammed. Road cut exposes several feet of till over bedrock.Vegetation:Spruce.Ground Surface: 2 to 3 feet thick organic mat/moss.Subsurface:2 to 6 feet of till over bedrock. Rock type is similar to rock seen at RC14.RC15Photo 43Fig. A-22RC16Photo 44Fig. A-22RC13RC14RC11Photo 41Fig. A-21RC12Photo 42Fig. A-21RC09Photo 40Fig. A-20RC10Photo ReferencePhoto CD RC09_A thru KPhoto CD RC10_A thru EPhoto CD RC11_A thru DPhoto CD RC12_A thru DPhoto CD RC13_A thru GPhoto CD RC14_A thru CPhoto CD RC15_A thru CPhoto CD RC16_A thru DPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 3 of 5Table 3SHANNON & WILSON, INC.Transmission Line - Jumbo Island/Deer Bay to Hydaburg Tie-inGPSPoint #Site DescriptionRelatively flat terrain on both sides of the road with a gentle downward slope toward the north. Potential area for deeper peat deposits, but shallow road cuts expose mineral soil and rock.Vegetation:Spruce. Logged area.Ground Surface:1 to 4 feet peat.Subsurface:1 to 4 feet of peat (based on peat probing) over till/ rock?Terrain steepens approx. 200 to 400 feet west of RC17. Road cuts reveal similar stratigraphy with up to 10 feet of till.Vegetation:Spruce.Ground Surface: 1 to 3 feet thick organic mat.Subsurface:Generally 2 to 4 feet of till over bedrock. Possible areas with till thickness up to 10 feet.Relatively flat terrain with peat/muskeg (approx. 400 long)Vegetation:Low spruce and moss.Ground Surface:Muskeg/peat.Subsurface:6 to 12 feet of peat/soft soils based on peat probing.Boggy area transition to rolling terrain with small hills and bogs in the low areas. Area has not been logged. Bogs typically 200 to 600 feet wide. Till exposed in road cuts.Vegetation:Low spruce. Logged area.Ground Surface:Muskeg/peat.Subsurface:8 to 12 feet of peat over till based on probes.Low lying area, ground still slopes gently downward toward the north. 2 to 3-foot high road cuts expose approx. 2 feet organic mat over till.Vegetation:Spruce.Ground Surface:Peat/moss.Subsurface:3 to 4 feet of peat over till based on probes.Longer bog feature. North side of road looks slightly higher with thinner peat growth (in cuts). Boggy area approx. 400 to 500 feet long. Peat probes were performed on both sides of the road.Vegetation:Spruce.Ground Surface: Peat/moss.Subsurface:7 to 10 feet of peat over till on south side of road. 3 to 4 feet of peat over till on north side of road.Still sloping downward toward the south. Less boggy areas around this location. Road cut exposes rock. Quarry site approx. 100 feet west.Vegetation:Spruce.Ground Surface: 2 to 3 feet thick organic mat/moss.Subsurface:2 to 4 feet of till over bedrock. Rock type: gray green, fine-grained meta-sandstone/phyllite with quartz veins.Transitioning to north facing slope and scattered bogs (approx. 200 to 300 feet long).Vegetation:Low spruce.Ground Surface: Peat/moss.Subsurface:5 to 15 feet of peat over till based on probing.RC23Photo 49Fig. A-25RC24RC21Photo 47Fig. A-24RC22Photo 48Fig. A-24RC19RC20Photo 46Fig. A-23RC17RC18Photo 45Fig. A-23Photo ReferencePhoto CD RC17_A thru FPhoto CD RC18_A thru DPhoto CD RC19_A thru CPhoto CD RC20_A thru C Photo CD RC21_A thru CPhoto CD RC22_A thru DPhoto CD RC23_A thru CPhoto CD RC24_A thru EPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 4 of 5Table 3SHANNON & WILSON, INC.Transmission Line - Jumbo Island/Deer Bay to Hydaburg Tie-inGPSPoint #Site DescriptionBoggy area (mostly on north side of road). Not connected to bog at RC24.Vegetation:Low Spruce.Ground Surface:Peat/moss.Subsurface:5 to 15 feet of peat over till based on probing.Bridge spans drainage. Terrain sloping downward toward the north. Road cuts expose 4 to 6 feet of till. No bedrock exposed in stream Vegetation:Spruce.Ground Surface: 1 to 3 feet thick organic mat.Subsurface:>4 to 6 feet of till.Slope steepens from this point westward. Terrain between here and RC26 is rolling with till exposed in shallow road cuts. Road cut exposes shallow bedrock.Vegetation:Spruce.Ground Surface: 2 to 3 feet thick organic mat.Subsurface:Pockets of till approx. 6 to 8 feet deep over bedrock. Rock type: Lightly metamorphosed, gray-green, siltstone/mudstone and sandstone with quartz veins.Tall road cut. Cut/rock face is approx. 15 feet high on south side of road. Isolated pockets of till.Vegetation:Spruce and alder.Ground Surface: 1 to 3 feet thick organic mat.Subsurface:2 to 8 feet of till over bedrock.Quarry site. Face is approx. 50 to 60 feet high. At top of hill in the road. Lots of rock exposed in cuts between this location and RC28.Vegetation:Spruce and alder.Ground Surface: 1 to 3 feet thick organic mat.Subsurface:Pockets of till to 6 feet thick over bedrock. Rock type: gray-green, metasiltstone and metasandstone.Long section of relatively flat road. Moderate slope down toward the north. Road cuts on south side of road (< 5 feet high) exposing till soils.Vegetation:Spruce and alder.Ground Surface: 2 to 4 feet thick organic mat.Subsurface:2 to 6 feet of till over bedrock.Heavily vegetated/forested along road without many soil or rock exposures. Short, 3 to 4-foot high road cut at this location.Vegetation:Spruce.Ground Surface: 1 to 3 feet thick organic mat.Subsurface:>4 feet of till over bedrock.Approx. 8-foot high road cut through bedrock on the south side of the road. Quarry approx. 300 feet west of this location.Vegetation:Spruce and alder.Ground Surface: 1 to 3 feet thick organic mat.Subsurface:1 to 3 feet of till over bedrock. Rock type: granite/granodioriteRC31Photo 54Fig. A-27RC32Photo 55Fig. A-19RC29Photo 52Fig. A-26RC30Photo 53Fig. A-27RC27Photo 51Fig. A-26RC28RC25RC26Photo 50Fig. A-25Photo ReferencePhoto CD RC25_A thru DPhoto CD RC26_A thru EPhoto CD RC27_A thru EPhoto CD RC28_A thru CPhoto CD RC29_A thru FPhoto CD RC30_A thru DRC31_A thru RC31_DPhoto CD RC32_A thru EPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 5 of 5Table 3SHANNON & WILSON, INC.Transmission Line - Jumbo Island/Deer Bay to Hydaburg Tie-inGPSPoint #Site DescriptionProposed transmission line ties into existing above-ground utility here. End of project.Vegetation:Spruce and alder.Ground Surface: 1 to 3 feet thick organic mat.Subsurface:Unknown.RC33Photo 56Fig. A-28Photo ReferencePhoto CD RC33_A thru CPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 1 of 2Table 4SHANNON & WILSON, INC.Access Road - Powerhouse to Lake MellenGPSPoint #Site DescriptionAccess road and bridge over Reynolds Creek. Bridge is steel framed with a timber deck.Vegetation: n/aGround Surface: n/aSubsurface: n/aQuarry site along access road. Road is in decent condition without signs of distress or washouts. Rocks up to 6 feet in diameter on quarry floor.Vegetation: n/a.Ground Surface: n/a.Subsurface: Bedrock. Rock type: Granite/granodiorite.Access road on steep side hill blocked by boulders.Vegetation: n/a.Ground Surface: n/a.Subsurface:n/aApprox. 75-foot section of road prone to sliding. Signs of old sloughs. Rock oriented favorable for road cut but existing bench is limited.Vegetation:n/aGround Surface: n/aSubsurface:Bedrock. Rock type: Albite-epidote hornfels with gneissic texture.Quarry site on access road. Road is in decent shape (no obvious signs of distress). Rock to 4 feet in diameter on quarry floor.Vegetation:n/aGround Surface: n/aSubsurface:Bedrock. Rock type: Granite/granodiorite.Quarry site on access road near Mellen Lake. Could make good rip rap up to 4 feet in diameter.Vegetation:n/aGround Surface: n/aSubsurface:Bedrock. Rock type: Granite/granodiorite; blockyAccess road above Mellen Lake and pond. Rock is available in road cutsVegetation:n/aGround Surface: n/aSubsurface:Bedrock. Rock type: Granite/granodiorite.Bridge between Mellen Lake and pond. Steel framed with timber deck. Shallow bedrock.Vegetation:n/aGround Surface: n/aSubsurface:n/aRC45RC46Photo 12Fig. A-6RC43RC44Photo 11Fig. A-6RC41Photo 10Fig. A-5RC42RC39Photo 8Fig. A-4RC40Photo 9Fig. A-5Photo ReferencePhoto CD RC39_A thru EPhoto CD RC40_A thru LPhoto CD RC41_A thru DPhoto CD RC42_A thru FPhoto CD RC43_A thru DPhoto CD RC44_A thru FPhoto CD RC45_A thru DPhoto CD RC46_A thru EPreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Field Reconnaissance NotesPage 2 of 2Table 4SHANNON & WILSON, INC.Access Road - Powerhouse to Lake MellenGPSPoint #Site DescriptionQuarry site. Potential north dam access route. Accessed from main road at quarry. A bit boggy with peat thinner on sides.Vegetation:Spruce.Ground Surface: 2 to 6 feet peat based on probes.Subsurface:Organics over bedrock. Further along north dam access route. Good pond access.Vegetation:Spruce.Ground Surface: 2 to 4 feet peat based on probes.Subsurface:Organics over bedrock. South dam access starting point. Lots of rock around area.Vegetation:Spruce.Ground Surface: 2 to 6 feet peat based on probes.Subsurface:Organics over bedrock. RC49Photo 14Fig. A-7RC47Photo 13Fig. A-7RC48Photo CD RC47_A thru CPhoto CD RC48_A thru DPhoto CD RC49_A thru DPhoto ReferencePreliminary Geotechnical ReportReynolds Creek Hydroelectric Project, Hydaburg, AlaskaHDR Engineering, Inc.September 200832-1-01993-001
Fig. 1SHANNON & WILSON, INC.
Geotechnical & Environmental Consultants
VICINITY MAP
Hydaburg, Alaska
September 2008 32-1-01993-001
Canada
Reynolds Creek Hydroelectric Project
Prince of Wales Island
Anchorage
MAP NOT TO SCALE
N
Project Area
Adapted from drawing provided
by HDR Engineering, Inc.
Reynolds Creek Hydroelectric Project
SEISMICITY MAP
Hydaburg, Alaska
September 2008
Fig. 10
32-1-01993-001
SHANNON & WILSON, INC.
Geotechnical & Environmental Consultants
Juneau
Ketchikan
Gulf of Alaska
Clarence
Strait
CanadaAlaska
Clarence
Strait
Fault
PROJECT
LOCATION
Thorne Bay
A
D
B
C
E
F
G
H
EARTHQUAKE KEY
Date MagnitudeDesignation on Map
A September 4, 1899 8.2-8.3
B September 10, 1899 7.8
C September 10, 1899 8.5-8.6
D October 9, 1900 8.3
E May 15, 1908 7.0
F October 24, 1927 7.1
G August 22, 1949 8.1
H July 10, 1958 7.9-8.0
I July 30, 1972 7.1-7.6
Earthquake greater than magnitude
4 in the Ketchikan area.
Project
Location
Map Not To Scale
Seismicity of Alaska
USGS National Earthquake
Information Center
I
N
Reynolds Creek Hydroelectric Project
GRADATION REQUIREMENTS
Hydaburg, Alaska
September 2008
Fig. 11
32-1-01993-001
SHANNON & WILSON, INC.
Geotechnical & Environmental Consultants
GRADATION REQUIREMENTS
E-1 Crushed Aggregate Surface Course
PERCENT PASSING
BY WEIGHTU.S. STANDARD SIEVE SIZE
1 in.
3/4 in.
3/8 in.
No. 4
No. 8
No. 40
No. 200
25 mm
19 mm
9.5 mm
4.75 mm
2.36 mm
0.300 mm
0.075 mm
100
70 - 100
50 - 85
35 - 65
20 - 50
15 - 30
8 - 15
English Metric
After: Alaska Department of Transportation Standards
Standard Specifications for Highway Construction
Select Material Type C (Shot-Rock)*
PERCENT PASSING
BY WEIGHTU.S. STANDARD SIEVE SIZE
24 in.
No. 4
600 mm
4.75 mm
100
10 Max. on minus
3-in. portion
English Metric
Crushed Aggregate Fill*
PERCENT PASSING
BY WEIGHTU.S. STANDARD SIEVE SIZE
3 in.
No. 4
75 mm
4.75 mm
100
10 Max. on minus
3-in. portion
English Metric
Coarse Aggregate Durability
L.A. Abrasion
Sulfate Soundness
Degradation Value
45 - 50 max. *
9 max.
30 min.
Test Type Percent Loss
Retained on #4 Sieve
* Surface Course = 45% max
Base Course = 50% max
Aggregate containing no muck, frozen material, roots, sod or
other deleterious matter and with a plasticity index not greater
than 6 as tested by WAQTC FOP for AASHTO T 89/T 90.
Meet the gradation as tested by WAQTC FOP for AASHTO
T 27/T 11.
*
SHANNON & WILSON, INC.
32-1-01993-001
APPENDIX A
PHOTO PAGES
Figures A-1 through A-28 Photos 1 through 56
SHANNON & WILSON, INC.
32-1-01993-001
APPENDIX B
PRIOR EXPLORATIONS
SHANNON & WILSON, INC.
32-1-01993-001
APPENDIX C
IMPORTANT INFORMATION ABOUT YOUR
GEOTECHNICAL/ENVIRONMENTAL REPORT
Page 1 of 2
3/2004
Attachment to 32-1-01993-001
Date: September 2008
To: HDR Engineering, Inc.
Re: Reynolds Creek Hydroelectric Project
Hydaburg, Alaska
SHANNON & WILSON, INC.
Geotechnical and Environmental Consultants
Important Information About Your Geotechnical/Environmental Report
CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS.
Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate for
a construction contractor or even another civil engineer. Unless indicated otherwise, your consultant prepared your report expressly for you
and expressly for the purposes you indicated. No one other than you should apply this report for its intended purpose without first
conferring with the consultant. No party should apply this report for any purpose other than that originally contemplated without first
conferring with the consultant.
THE CONSULTANT'S REPORT IS BASED ON PROJECT-SPECIFIC FACTORS.
A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project-specific factors.
Depending on the project, these may include: the general nature of the structure and property involved; its size and configuration; its
historical use and practice; the location of the structure on the site and its orientation; other improvements such as access roads, parking lots,
and underground utilities; and the additional risk created by scope-of-service limitations imposed by the client. To help avoid costly
problems, ask the consultant to evaluate how any factors that change subsequent to the date of the report may affect the recommendations.
Unless your consultant indicates otherwise, your report should not be used: (1) when the nature of the proposed project is changed (for
example, if an office building will be erected instead of a parking garage, or if a refrigerated warehouse will be built instead of an
unrefrigerated one, or chemicals are discovered on or near the site); (2) when the size, elevation, or configuration of the proposed project is
altered; (3) when the location or orientation of the proposed project is modified; (4) when there is a change of ownership; or (5) for
application to an adjacent site. Consultants cannot accept responsibility for problems that may occur if they are not consulted after factors,
which were considered in the development of the report, have changed.
SUBSURFACE CONDITIONS CAN CHANGE.
Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report is
based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose
adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for
example, groundwater conditions commonly vary seasonally.
Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or groundwater fluctuations may also affect
subsurface conditions and, thus, the continuing adequacy of a geotechnical/environmental report. The consultant should be kept apprised of
any such events, and should be consulted to determine if additional tests are necessary.
MOST RECOMMENDATIONS ARE PROFESSIONAL JUDGMENTS.
Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data were
extrapolated by your consultant, who then applied judgment to render an opinion about overall subsurface conditions. The actual interface
between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may differ from
those predicted in your report. While nothing can be done to prevent such situations, you and your consultant can work together to help
reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly beneficial in this respect.
Page 2 of 2
3/2004
A REPORT'S CONCLUSIONS ARE PRELIMINARY.
The conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions
revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can be
discerned only during earthwork; therefore, you should retain your consultant to observe actual conditions and to provide conclusions. Only
the consultant who prepared the report is fully familiar with the background information needed to determine whether or not the report's
recommendations based on those conclusions are valid and whether or not the contractor is abiding by applicable recommendations. The
consultant who developed your report cannot assume responsibility or liability for the adequacy of the report's recommendations if another
party is retained to observe construction.
THE CONSULTANT'S REPORT IS SUBJECT TO MISINTERPRETATION.
Costly problems can occur when other design professionals develop their plans based on misinterpretation of a geotechnical/environmental
report. To help avoid these problems, the consultant should be retained to work with other project design professionals to explain relevant
geotechnical, geological, hydrogeological, and environmental findings, and to review the adequacy of their plans and specifications relative
to these issues.
BORING LOGS AND/OR MONITORING WELL DATA SHOULD NOT BE SEPARATED FROM THE REPORT.
Final boring logs developed by the consultant are based upon interpretation of field logs (assembled by site personnel), field test results, and
laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in
geotechnical/environmental reports. These final logs should not, under any circumstances, be redrawn for inclusion in architectural or other
design drawings, because drafters may commit errors or omissions in the transfer process.
To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete
geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared for
you, you should advise contractors of the report's limitations, assuming that a contractor was not one of the specific persons for whom the
report was prepared, and that developing construction cost estimates was not one of the specific purposes for which it was prepared. While a
contractor may gain important knowledge from a report prepared for another party, the contractor should discuss the report with your
consultant and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for construction cost
estimating purposes. Some clients hold the mistaken impression that simply disclaiming responsibility for the accuracy of subsurface
information always insulates them from attendant liability. Providing the best available information to contractors helps prevent costly
construction problems and the adversarial attitudes that aggravate them to a disproportionate scale.
READ RESPONSIBILITY CLAUSES CLOSELY.
Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design
disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem,
consultants have developed a number of clauses for use in their contracts, reports and other documents. These responsibility clauses are not
exculpatory clauses designed to transfer the consultant's liabilities to other parties; rather, they are definitive clauses that identify where the
consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and take
appropriate action. Some of these definitive clauses are likely to appear in your report, and you are encouraged to read them closely. Your
consultant will be pleased to give full and frank answers to your questions.
The preceding paragraphs are based on information provided by the
ASFE/Association of Engineering Firms Practicing in the Geosciences, Silver Spring, Maryland
Appendix B
Instream Flow Pipe Calculations
Appendix C
Marine Access Technical Memorandum
Appendix D
Diversion Dam Spillway Calculations
Appendix E
Surge Analysis Report
0
2
x
Hvt
H
x
v
g
a (1)
04
Dx
Hgx
vvt
v (2)
t x H
a =v g
D
= f |v|v/f
Reynolds Creek P hIntake Structure near Lake MellenPowerhouseEl. 107 ftEl. 860.5 ftHWL = 876 ftOperating WL = 872 ftFuture HWL = 905 ftSTA 25+68Bypass42-inch diameter steel penstockSTA25+68Pelton wheel penstock alignmentTurgo penstock alignmentSTA 5+60STA 4+90STA 1+95Valve VaultN1”0ValveVaultand Vent PipeScale: 1” = 400’Figure 1: Schematic (Plan) of Reynolds Creek Hydroelectric Project60042 April 2010
0.40.50.60.70.80.91Cv / Cvfully open00.10.20.30 10 20 30 40 50 60 70 80 90 100% OpenFigure 2: Needle Valve Characteristic Curve
Figure 3: Sleeve Valve Characteristic Curve (Courtesy of Bailey Valve)60042 April 2010
nv-c.avi
Surge Control
nv-c-wp.avi
lr-wp.avi
Turbine Shut-off Valve Normal Closure
tsv-c-wp.avi
lr-wp-fs.avi
Turbine Shut-off Valve Fail-Safe Closure
la-wp.avi
lv-wp.avi
Valve Closure
bp-c-wp.avi
Valve Opening
bp-o-wp.avi
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Valve Vault05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 4: HGL elevations in penstock following sudden closure of one needle valve with an operating levelat the intake (Exceptional Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Exceptional)PowerhouseIntakeSTA 5+60Vapor pressureSTA 25+68
4006008001,0001,2001,400Pressure Head (ft)Sudden closure of one needle valve at PowerhousePressure spike created by slam closure of air/vacuum valve at STA 4+90-20002000 10 20 30 40 50 60 70 80 90 100Time (sec)Figure 5: Pressure head records following sudden closure of one needle valve withan operating level at the intake (Exceptional Condition)PowerhouseSTA 5+60-20 ft
(a)
(b)
Figure 6: (a) Vacuum relief / air inlet valve, and (b) slow closing combination
air valve (Courtesy of Valmatic)
60042 April 2010
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Valve VaultVacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 7: HGL elevations in penstock following sudden closure of one needle valve with an operating level at the intake and additional surge protection (Exceptional Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Exceptional)PowerhouseIntakeSTA 5+60STA 25+68STA 4+90
4006008001,0001,2001,400Pressure Head (ft)Sudden closure of one needle valve at Powerhouse-20002000 10 20 30 40 50 60 70 80 90 100Time (sec)Figure 8: Pressure head records following sudden closure of one needle valve with an operating level at the intake and additional surge protection (Exceptional Condition)PowerhouseSTA 5+60Vacuum valve opens
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 9: HGL elevations in penstock following load rejection and 120 second closure of needle valves from90 cfs with an operating level at the intake and additional surge protection (Normal Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Normal)PowerhouseValve VaultIntakeSTA 5+60STA 25+68STA 4+90
4006008001,0001,2001,400Pressure Head (ft)Needle valves at Powerhouse closed-20002000 50 100 150 200 250Time (sec)Figure 10: Pressure head records following load rejection and 120 second closure of needle valves from 90 cfs with an operating level at the intake and additional surge protection (Normal Condition)PowerhouseSTA 5+60
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 11: HGL elevations in penstock following load rejection and 120 second closure of turbine shut-off valvefrom 90 cfs with an operating level at the intake and additional surge protection (Normal Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Normal)Power-houseValve VaultIntakeSTA 5+60STA 25+68STA 4+90
4006008001,0001,2001,400Pressure Head (ft)Turbine shut-off valve at Powerhouse closed-20002000 50 100 150 200 250Time (sec)Figure 12: Pressure head records in penstock following load rejection and 120 second closure of turbine shut-off valve from 90 cfs with an operating level at the intake and additional surge protection (Normal Condition)PowerhouseSTA 5+60
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 13: HGL elevations in penstock following load rejection and 30 second fail-safe closure of needle valves from 90 cfs with an operating level at the intake and additional surge protection (Emergency Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Emergency)PowerhouseValve VaultIntakeSTA 5+60STA 25+68STA 4+90
4006008001,0001,2001,400Pressure Head (ft)Needle valves at Powerhouse closed-20002000 10 20 30 40 50 60 70 80 90 100Time (sec)Figure 14: Pressure head records following load rejection and 30 second fail-safe closure of needle valves from 90 cfs with an operating level at the intake and additional surge protection (Emergency Condition)PowerhouseSTA 5+60
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 15: HGL elevations in penstock following load rejection and 30 second fail-safe closure of turbine shut-off valve from 90 cfs with an operating level at the intake and additional surge protection (Emergency Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Emergency)Power-houseValve VaultIntakeSTA 5+60STA 25+68STA 4+90
4006008001,0001,2001,400Pressure Head (ft)Turbine shut-off valve at Powerhouse closed-20002000 10 20 30 40 50 60 70 80 90 100Time (sec)Figure 16: Pressure head records following load rejection and 30 second fail-safe closure of turbine shut-off valve from 90 cfs with an operating level at the intake and additional surge protection (Emergency Condition)PowerhouseSTA 5+60
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 17: HGL elevations in penstock after 120 second opening of needle valves to 90 cfs and load acceptance with an operating level at the intake and additional surge protection (Normal Condition)Max. HGLMin. HGLStatic HGLPipeline Profile (Crown)Max. Allowable HGL (Normal)PowerhouseValve VaultIntakeSTA 5+60STA 25+68STA 4+90Max. & Static HGL Coincident
4006008001,0001,2001,400Pressure Head (ft)Needle valves at Powerhouse opened to 90 cfs-20002000 20 40 60 80 100 120 140 160 180 200Time (sec)Figure 18: Pressure head records after 120 second opening of needle valves to 90 cfs and load acceptance with an operating level at the intake and additional surge protection (Normal Condition)PowerhouseSTA 5+60
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 19: HGL elevations in penstock after load variance from 0 cfs to 30 cfs with an operating level at the intake and additional surge protection (Normal Condition)Max. HGLMin. HGLStatic HGLPipeline Profile (Crown)Max. Allowable HGL (Normal)PowerhouseValve VaultIntakeSTA 5+60STA 25+68STA 4+90Max. & Static HGL Coincident
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 20: HGL elevations in penstock after load variance from 30 cfs to 60 cfs with an operating level at the intake and additional surge protection (Normal Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Normal)PowerhouseValve VaultIntakeSTA 5+60STA 25+68STA 4+90Max. & Steady State HGL Coincident
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 21: HGL elevations in penstock after load variance from 60 cfs to 90 cfs with an operating level at the intake and additional surge protection (Normal Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Normal)PowerhouseValve VaultIntakeSTA 5+60STA 25+68STA 4+90Max. & Steady State HGL Coincident
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 22: HGL elevations in penstock following 60 second closure of bypass sleeve valve from 50 cfs with an operating level at the intake and additional surge protection (Normal Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Normal)PowerhouseValve VaultIntakeSTA 5+60STA 25+68STA 4+90Min. and Steady State HGL Coincident
4006008001,0001,2001,400Pressure Head (ft)Sleeve valve on bypass closed-20002000 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150Time (sec)Figure 23: Pressure head records following 60 second closure of bypass sleeve valve from 50 cfs with an operating level at the intake and additional surge protection (Normal Condition)Bypass Sleeve ValveSTA 5+60
1,5002,0002,5003,0003,500Elevation (ft)Air/vacuum valveVent Pipe atSTA 1+95Vacuum relief valve with controlled venting feature05001,0000 500 1,000 1,500 2,000 2,500 3,000 3,500Distance (ft)Figure 24: HGL elevations in penstock following 60 second opening of bypass sleeve valve to 50 cfswith an operating level at the intake and additional surge protection (Normal Condition)Max. HGLMin. HGLSteady State HGLPipeline Profile (Crown)Max. Allowable HGL (Normal)PowerhouseValve VaultIntakeSTA 5+60STA 25+68STA 4+90Max. and Steady State HGL Coincident
4006008001,0001,2001,400Pressure Head (ft)Sleeve valve on bypass open-20002000 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150Time (sec)Figure 25: Pressure head records following 60 second opening of bypass sleeve valve to 50 cfs with an operating level at the intake and additional surge protection (Normal Condition)Bypass Sleeve ValveSTA 5+60
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Appendix F-1
Penstock Design Calculations
Appendix F-2
Penstock Anchor Calculations