HomeMy WebLinkAboutSchubee Lake Hydroelectric Project Reconnaissance Report - Mar 2012 - REF Grant 7040067Schubee Lake
Hydroelectric Project
Reconnaissance Report
Prepared for:
Alaska Power & Telephone
PO Box 459
Skagway, AK 99840
Prepared by:
HDR Alaska, Inc.
2525 C Street, Suite 305
Anchorage, AK 99503
March 2012
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Table of Contents
1 Introduction .............................................................................................................................. 1
2 Hydrology ................................................................................................................................. 3
2.1 Schubee Lake Basin Characteristics ............................................................................. 3
2.2 Regional Hydrology ...................................................................................................... 4
2.2.1 Comparable Gages ........................................................................................... 4
2.2.2 Long-term Flows for Schubee Lake ................................................................ 5
2.3 Flood Frequency Analysis ............................................................................................ 7
2.3.1 Regression Analysis ......................................................................................... 7
2.3.2 Bulletin 17B with Adjusted Dorothy Lake Data .............................................. 8
3 Geology ..................................................................................................................................... 9
4 Active Storage ........................................................................................................................ 10
5 Project Arrangement ............................................................................................................. 11
5.1 Alternative Screening ................................................................................................. 11
5.1.1 Intake ............................................................................................................. 12
5.1.2 Water Conveyance ......................................................................................... 12
5.1.3 Powerhouse Location ..................................................................................... 13
5.2 Diversion to Kasidaya Creek ...................................................................................... 14
5.3 Project Configuration .................................................................................................. 14
6 Energy Generation ................................................................................................................. 15
7 Model Assumptions ................................................................................................................ 15
7.1 Model Operation ......................................................................................................... 16
7.2 Results ......................................................................................................................... 16
7.3 Sensitivity Analysis .................................................................................................... 16
7.3.1 Winter Inflow .................................................................................................17
7.3.2 Overall Hydrology ......................................................................................... 17
7.3.3 Storage ........................................................................................................... 17
7.3.4 Environmental Flow Release ......................................................................... 17
7.3.5 Firm Winter Capacity .................................................................................... 17
8 Cost Estimates ........................................................................................................................ 18
8.1 Results ......................................................................................................................... 18
9 LAND AND LAND RIGHTS ................................................................................................ 19
10 Environmental Considerations ............................................................................................. 19
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10.1 Fish Resources ............................................................................................................ 19
10.2 Visual Impact .............................................................................................................. 20
10.3 Water Quality .............................................................................................................. 20
10.4 Recreation ................................................................................................................... 20
10.5 Subsistence, Cultural and Historical Resources .......................................................... 20
10.6 Land Ownership, Mining Claims, and Water Rights .................................................. 20
11 Licensing/Permitting.............................................................................................................. 20
12 Conclusions and Recommendations ..................................................................................... 21
List of Tables
Table 1. Lemon Creek, Upper Chilkoot Lake, Goat Lake, and Dorothy Lake gages. .................... 5
Table 2 - Correlation to Dorothy Lake ............................................................................................ 6
Table 3. Regression equation flood discharge estimates for 5-500 year recurrence intervals. ....... 8
Table 4. Bulletin 17B flood discharge estimates for 5-500-year recurrence intervals. .................. 9
Table 5 - Schubee Lake Storage .................................................................................................... 11
Table 6. Summary of Energy Parameters ..................................................................................... 16
Table 7: Firm Capacity and Energy Estimate ............................................................................... 17
Table 8 - Opinion of Probable Cost ............................................................................................... 19
List of Figures
Figure 1 - Project Area .................................................................................................................... 2
Figure 2. Schubee Lake Drainage Basin ........................................................................................ 3
Figure 3. Long-term average daily flows at Dorothy Lake Outlet (USGS gage# 15039900)
Lemon Creek (USGS gage# 15052000), and Kadashan River (USGS gage #
15106920) ..................................................................................................................... 4
Figure 4 - Average Monthly Flow ................................................................................................... 6
Figure 5 - Flow Duration Curve ...................................................................................................... 7
Figure 6. Regression equation-based flood frequency curve for Schubee Lake Outlet. ................ 8
Figure 7. Flood frequency estimates for Schubee Lake Outlet based on adjusting the Dorothy
Lake Outlet record by drainage area and precipitation differences. .............................. 9
Figure 8 - Schubee Lake Depth Readings ..................................................................................... 10
Figure 9 - Project Cross-section .................................................................................................... 14
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List of Appendices
Appendix A – Schubee Lake Hydroelectric Reconnaissance Report, Golder & Associates
Appendix B – Schubee Energy
Appendix C – Schubee Cost Estimate, December 2011
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1 Introduction
Alaska Power & Telephone (AP&T) contracted with HDR Alaska, Inc. to evaluate the feasibility
of a small hydroelectric project located at Schubee Lake near Skagway, Alaska. APT received a
FERC preliminary permit to investigate this project on November 30, 2010.
The project is located approximately 7 miles south of Skagway, AK on the east side of Taiya
Inlet (Figure 1). Schubee Lake is located at an elevation of approximately 3360 ft above mean
sea level (MSL), with a maximum depth of over 300 ft and surface area of 283 acres. The
project area is remote and, with the exception of the lake itself, very steep. Current access is
limited to helicopters.
The FERC permit identified several alternatives for project development. This reconnaissance
report examines the viability of these alternatives and other concepts for development of a
project at Schubee Lake. The scope of work defined for this assignment included:
Field reconnaissance by team members;
Review of available project documentation and related information;
Development of conceptual alternatives;
Evaluation of project hydrology;
Estimation of energy production and new facility costs;
Preparation of this reconnaissance report.
This report is believed to be the first study for a hydroelectric project at this location.
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Figure 1 - Project Area
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2 Hydrology
2.1 Schubee Lake Basin Characteristics
Schubee Glacier, Lake, and Creek are located above Taiya Inlet on the Southeast Alaska
mainland, about 14 miles south of Skagway and 150 miles north of Juneau (Figure 1). The
drainage basin above the lake outlet averages 4000 feet in elevation. The lake is at elevation
3360 ft., and the highest point on the basin is 6225 ft. The lake drains down a steep slope into
Taiya Inlet. Schubee Lake at the outlet drains 2.7 square miles, of which 1.1 square miles is
glacier and 0.45 square miles is lake. The remaining area is steep, rocky terrain (Figure 2).
Figure 2. Schubee Lake Drainage Basin
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2.2 Regional Hydrology
Because insufficient flow data exist for Schubee Lake, nearby gages with similar characteristics
are needed to provide a reasonable estimate of mean daily flow. The most important
characteristics include elevation, precipitation, glacial area, and lake area. High elevation
drainage basins in Southeast Alaska differ from lower elevation basins primarily in the
proportion of annual runoff that is snowmelt. While lower elevation drainages often have both a
spring snowmelt peak and runoff throughout the winter during storms, high elevation drainage
basins typically have low flows throughout the winter and a more pronounced and sustained
snowmelt peak throughout the summer. In basins with substantial glacial area, the summer
runoff peak is more pronounced, and basins with more lake storage will typically show less
varied flow throughout the summer. Mean annual precipitation is an important characteristic,
but also difficult to estimate with accuracy at high elevations. To illustrate the differences in
runoff, the annual hydrographs from Lemon Creek and Dorothy Lake Outlet near Juneau, both
high elevation glacial drainages, and a low elevation drainage, Kadashan River near Tenakee, are
shown below. The Lemon Creek drainage has a much higher percentage of glacial area, and
shows increased summer flow and decreased winter flow compared to Dorothy Lake.
Figure 3. Long-term average daily flows at Dorothy Lake Outlet (USGS gage# 15039900) Lemon Creek
(USGS gage# 15052000), and Kadashan River (USGS gage # 15106920)
2.2.1 Comparable Gages
The nearest gaging stations to Schubee Lake are Upper Chilkoot Lake Outlet near Haines (USGS
15056280), Goat Lake Outlet near Skagway (USGS 15056095), Lemon Creek near Juneau
(USGS 15052000) and Dorothy Lake Outlet near Juneau (USGS 15039900). The characteristics
of these gages are summarized in Table 1.
Although all of the gages are in the same general area of southeast Alaska, annual runoff varies
greatly. For comparison purposes, the long-term average precipitation in Juneau, Haines and
0
5
10
15
20
25
30
35
40
45
50
Mean Daily Runoff(cfs/square mile)
Dorothy Lake Outlet
Lemon Creek
Kadashan River
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Skagway is 58”, 48” and 26” per year. These precipitation values generally correlate with the
gaged runoff and explain the differences in mean annual runoff in the different drainage basins.
Table 1. Lemon Creek, Upper Chilkoot Lake, Goat Lake, and Dorothy Lake gages.
Name Gage#Start End
Drainage
Area
(miles2)
Glacier
Area
(%)
Mean Basin
Elevation
(ft)
Mean Annual
Runoff
(cfs/ mile2)
Lemon Creek near
Juneau
15052000 1952 2010 12.3 67 3430 13.2
Dorothy Lake Outlet
near Juneau
15039900 1987 2003 11.0 35 3450 9.8
Upper Chilkoot Lake
Outlet near Haines
15056280 1993 1997 4.6 40 ~3000 8.2
Goat Lake near
Skagway
15056095 1991 1997 2.92 21 ~4000 4.1
Schubee Lake -- -- -- 2.7 41 ~4000
2.2.2 Long-term Flows for Schubee Lake
Ideally it is desirable to have a long term record of flow data specific for the site in question.
However, this type of data is almost never available for small hydroelectric projects, particularly
in Alaska. Consequently, existing data from nearby gages is correlated to the project site in
question to create synthetic data for analysis. Of the nearby gages, Upper Chilkoot Lake (more
commonly called Connelly Lake) is 13 miles to the northwest and considered to be the most
similar to the Schubee Lake basin. Unfortunately, this gage only has 4 years of complete data.
To extend the synthetic period of record for Schubee Lake, the Upper Chilkoot Lake gage was
correlated on a monthly basis to the gage at the outlet to Dorothy Lake. This result was then
scaled by the ratio of drainage basins between Upper Chilkoot Lake and Schubee Lake. The
resulting scale factors are shown in Table 2 below. The average annual flow and a flow duration
curve are presented in Figures 4 & 5.
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Table 2 - Correlation to Dorothy Lake
Month Correlation
Jan 0.1
Feb 0.1
Mar 0.1
Apr 0.1
May 0.15
Jun 0.25
Jul 0.25
Aug 0.25
Sep 0.2
Oct 0.13
Nov 0.1
Dec 0.1
Figure 4 - Average Monthly Flow
0
10
20
30
40
50
60
70
80
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecFlow, cfs
Schubee Lake
Average Monthly Flow
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Figure 5 - Flow Duration Curve
2.3 Flood Frequency Analysis
Two flood frequency analyses were performed for Schubee Lake at the outlet. The first is based
on the regression equations of Curran et. al, 2003, and is specific to the Schubee Lake basin. The
second is based on the adjusted record at Dorothy Lake Outlet.
2.3.1 Regression Analysis
Input data for a flood regression analysis in Southeast Alaska includes drainage area, percentage
area in lakes and ponds, and mean minimum January temperature. The results, along with the
5% and 95% confidence limits, are shown on Figure 6 and Table 3.
0
50
100
150
200
250
0 20 40 60 80 100Flow, cfs
% Exceedance
Schubee Lake
Flow Duration Curve
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Figure 6. Regression equation-based flood frequency curve for Schubee Lake Outlet.
Table 3. Regression equation flood discharge estimates for 5-500 year recurrence intervals.
Recurrence
Interval
(years)
Regression
Equation
(cfs)
5% (cfs) 95%
(cfs)
5 134 71 252
10 162 86 307
25 199 104 384
50 228 116 449
100 258 128 519
200 290 140 600
500 333 155 719
2.3.2 Bulletin 17B with Adjusted Dorothy Lake Data
Sixteen years of flow peaks for Dorothy Lake Outlet were adjusted by multiplying by the
drainage area ratio (0.25) and the apparent precipitation ratio (0.8). The Bulletin 17B analysis
based on adjusted Dorothy Lake records indicates similar results as the regression analysis, but
smaller confidence limits (Figure 7, Table 4).
0
100
200
300
400
500
600
700
800
5 10 25 50 100 200 500Discharge (cfs)
RecurrenceInterval (years)
Regression Equation 5%95%
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Figure 7. Flood frequency estimates for Schubee Lake Outlet based on adjusting the Dorothy Lake Outlet
record by drainage area and precipitation differences.
Table 4. Bulletin 17B flood discharge estimates for 5-500-year recurrence intervals.
Recurrence
Interval
Bulletin17B 5% 95%
5 171 154 197
10 190 169 227
25 213 187 266
50 230 199 295
100 246 210 324
200 262 221 353
500 283 235 392
3 Geology
A separate geologic investigative report (Appendix A) was prepared for this project. This report
generally concluded that:
the project site seems conducive for general underground construction;
surface project features could be subjected to avalanche and seismic risks;
the lake outlet is not a good candidate for dam construction;
access would be difficult, particularly on the steep slopes.
The information provided by this report has been used in the evaluation of alternatives below.
0
50
100
150
200
250
300
350
400
450
5 10 25 50 100 200 500Discharge (cfs)
recurrance interval (years)
Bulletin17B 5%95%
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4 Active Storage
With any hydroelectric project, energy generation will increase and operational concerns will
ease if storage of water is possible in comparison to the same project operating in a run-of-river
mode. The initial amount of storage to capture this benefit is usually small in comparison to the
annual yield of the basin. This operational storage may only be equivalent to a few minutes,
hours or days of operation.
Active storage in excess of operational storage would allow the ability to seasonally shift
generation by capturing high flows (that might otherwise have passed as spill) and release this
water later in the year (to supplement low natural flows). For the Schubee Lake project it is
assumed that being able to provide active storage is the prime objective of the project and that
storage needs to be maximized.
A bathymetric survey of Schubee Lake was not part of this study. However, limited depth
readings have been made as shown in Figure 8. From these readings and existing mapping data
an approximate stage vs. storage relationship was derived as shown in Table 5.
Figure 8 - Schubee Lake Depth Readings
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Table 5 - Schubee Lake Storage
Stage Relative
Storage, AF
Surface
Area, Ac
3360 23863 283.0
3350 21079 273.8
3340 18387 264.7
3330 15785 255.8
3320 13271 246.9
3310 10845 238.2
3300 8506 229.6
3290 6253 221.0
3280 4085 212.6
3270 2001 204.3
3260 0 196.0
5 Project Arrangement
AP&T’s FERC preliminary permit identified multiple options for development as described
below:
A siphon intake including a fabricated steel intake screen; approximately 200-foot-long,
24-inch-diameter high-density polyethylene pipe connecting the intake screen to a
vacuum tank and pump in an enclosed pump house;
A conventional intake 20-foot-high integral to a 200-foot-long timber, rockfill, and
concrete dam;
An above-ground penstock connecting the intake to the powerhouse consisting of an
above ground, 7,100-foot-long, 24-inch-diameter steel pipe and associated thrust blocks
and expansion joints;
An approximately 7,200-foot-long, 28-inch-diameter directional-bored tunnel with steel
liner;
A new powerhouse containing a single turbine/generator unit with an installed capacity of
4,900 kilowatts;
A 9-mile-long, 34.5-kilovolt transmission line connected to the grid in the Haines area
via a submarine cable.
5.1 Alternative Screening
The selection of the preferred alternatives for development largely centers on constructability.
The principle choices are intake type, water conveyance method and powerhouse location. Each
of these is evaluated below.
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5.1.1 Intake
The outlet of Schubee Lake is controlled by a long, narrow, pervious moraine. It is doubtful that
any type of new structure could be constructed on top of this moraine without significant
expense and effort. Additionally, due to the porosity of this moraine and the talus filled trough at
the south end of the lake, additional significant leakage could occur if the lake level was
increased. As such, a conventional type of intake that would require raising the lake level is not
considered economically viable.
Other options for intakes could be either a siphon system or a lake tap. There are advantages and
disadvantages to each and at this level of study, both are considered viable. Assuming that the
siphon could be trenched through the moraine five feet below the existing level, the siphon
intake would provide for approximately 20-25 feet of drawdown. A lake tap could be done over
a wide range of depths.
5.1.2 Water Conveyance
An above ground alternative would require either an access road or skyline to construct. A road
would be extremely difficult and expensive to construct. The road would require extensive
blasting and the crossing of extensive talus slopes. The cut slopes would have extensive cut
faces creating a large visual impact. It is also doubtful that the road could be aligned to
adequately access the penstock route.
Skylines have been used successfully in the past to construct penstocks on steep slopes. A key
element of the skyline system is being able to establish ground holds to anchor the lead line. The
geography of the site would require that the lower end be barge mounted. This could pose
several problems. First, Taiya Inlet can experience significant weather which would make
anchoring and accessing the barge extremely challenging. Second, Taiya Inlet is a major
waterway which has significant amounts of traffic during the summer months during which time
construction would need to take place. A barge and cable system partially across the inlet could
be considered a navigation hazard and not allowed. There would also be a visual impact but not
to the extent of what would occur with the road alternative.
Due to the above considerations, an underground water conveyance system appears to be the
only practical means of water conveyance. An underground conveyance system could be
constructed by one of two excavation methods: drilling/boring; drill and blast tunnel/shaft. Each
method is evaluated below.
5.1.2.1 Drilling/Raise Boring
With the drilling and boring method a small diameter pilot hole would be drilled from the top to
an elevation of that near the powerhouse. A conventional horseshoe-shaped tunnel would then
be driven to intersect the bore hole. A cutting head would be attached at the bottom of the pilot
hole and raised. The cuttings from the bore would fall to the bottom and would then be mucked
out. Typically the pilot hole is bored vertically however slight inclines are possible.
The advantages to this excavation method are that a smaller diameter hole can be created and the
hole could possibly be excavated in a shorter time period. There are several disadvantages to
this approach:
All equipment necessary to perform the drilling needs to mobilized to the top of the
project. This equipment is heavy and would necessitate the mobilization of a heavy lift
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helicopter from outside of Alaska. Additionally, the drilling and boring could not be
done by the same drill rig so two types of drill rigs would have to mobilized.
All support for the drilling and boring operations would be via helicopter. Harsh weather
could lead to low productivity and curtailed operations.
The length of the raise bore is near the longest of what has been done historically
(1260m) and would necessitate the use of the largest raise bore rig available.
Contractors capable of performing this type of work may not be available in Alaska.
5.1.2.2 Drill and Blast
The drill and blast method is the most common rock excavation method. With the drill and blast
method a pattern of drill holes are advanced approximately one diameter in front of the face.
The drill holes are then loaded and blasted and the muck is removed. This process is then
repeated. For this project a horizontal tunnel would be driven approximately 5,200 feet into the
mountain. From there a vertical shaft would be constructed to the intake.
The advantage to this type of excavation is that it is well understood and it is a relatively simple
process. It also allows for localized stabilization and rock treatment that may allow for an
unlined excavation. The main disadvantage is that the size of the tunnel and shaft required to
support construction is far greater than the size required to transport the water.
5.1.2.3 Directional Drilling
Directional drilling, in which a pilot hole is drilling directly between two points and then the hole
enlarged by reaming, is a construction method that is gaining in popularity. Directional drilling
is most often used to go under an obstacle such as a road or waterway. The equipment required
for large scale directional drilling is large and consists of many components.
For Schubee Lake, a directional drill of approximately 14,000 feet would be required. While a
very limited number of drills of this length have been performed with considerable efforts in the
oil industry, this length is typically beyond the capabilities of normal contractors. Due to the
length required, the difficulty of access, the hard rock conditions, the lack of qualified
contractors and the inability to obtain any reliable cost information, this concept has not been
reviewed in this report.
5.1.3 Powerhouse Location
Typically powerhouses are situated to allow the water to be returned to the natural water body
from which it originated. This is normally in support of maintaining downstream conditions.
However, in this case the ground at the creek terminus is extremely steep and the expense and
difficulty of trying to locate a powerhouse near the creek terminus is not warranted. The most
practical location is approximately one mile south of the creek terminus. This location provides
a modest amount of shelter for access and the terrain is less steep.
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5.2 Diversion to Kasidaya Creek
One alternative that has been suggested is to divert runoff from the Schubee Lake basin north to
the Kasidaya Creek basin where a hydroelectric project already exists. The Kasidaya Creek
hydroelectric project has an installed capacity of 3 MW and operates only during the April-
November timeframe due to weather constraints. This alternative would consist of an intake at
Schubee Lake, a 3-mile-long tunnel to Kasidaya Creek and a new 3.8 MW powerhouse just
upstream of the Kasidaya Creek intake. A short transmission line would connect the new
powerhouse to the existing submarine cable located near the Kasidaya Creek powerhouse.
5.3 Project Configuration
Based upon the above discussion and preliminary potential energy analysis, the base case project
configuration consists of:
A siphon intake including a fabricated steel intake screen; approximately 250-foot-long,
24-inch-diameter high-density polyethylene pipe connecting the intake screen to a
vacuum tank and pump in an enclosed pumphouse;
An approximately 3,700-foot-long, 30-inch-diameter raise-bored shaft. The shaft would
be inclined at 30 degrees from vertical to reduce overall tunnel length;
An approximately 6,500-foot-long unlined and unpressurized 8-foot horseshoe tunnel;
An approximately 6,500-foot-long, 18-inch-diameter steel penstock in the tunnel.
A new powerhouse containing a single turbine/generator unit with an installed capacity of
4,900 kilowatts located approximately one mile south of Schubee Creek on Taiya Inlet;
A 9-mile-long, 34.5-kilovolt transmission line connected to the grid in the Haines area
via a submarine cable.
The basic configuration is shown in Figure 9 below.
Figure 9 - Project Cross-section
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6 Energy Generation
The amount of energy that can be produced from hydroelectric projects is a function of the
amount of available water and in the case of storage projects, how the available water can be
regulated (systematically released). For Schubee Lake, in addition to the average annual energy,
the firm capacity attainable during winter months is of particular importance. For hydroelectric
projects, the firm capacity is almost always lower than the installed generation capacity for a
project. For the purposes of this study work, firm capacity is defined as:
“The amount of power the project can generate on a continuous
basis from Nov. 1 through April 30 with 100% reliability”
The firm capacity is always driven by low periods in the hydrologic cycle. Since the hydrologic
cycle varies, it is also desired to know at what level of reliability the project can generate at
levels higher than the firm capacity. It should be noted that this is only one manner of
regulation. The water can be regulated in a variety of different means in order to achieve other
objectives, such as peaking, spinning reserve or backup capacity.
For this study, the average annual energy and winter plant capacities were estimated using a
HDR proprietary energy modeling software tool customized for this particular purpose. Major
assumptions used in the modeling efforts are presented below.
7 Model Assumptions
Inflow hydrology was based upon USGS gage #15039900 located at Lake Dorothy and
scaled by a drainage area correction factors as described above.
Reservoir capacity and area curves were approximated using LIDAR and USGS
topographical data and depth measurements provided by AP&T.
Tailwater was assumed to be a constant at the turbine centerline of El. 20.
Environmental flow releases into Schubee Creek were assumed to be zero.
Equipment performance was based on generic data.
Headloss estimates were based on the assumed water conveyance design.
The reservoir was assumed to start full at the beginning of the simulation and was
allowed to fluctuate over the remaining period of the simulation.
Generation from Nov. 1 to April 30 “winter” was at a constant capacity level (“block
loaded”).
Generation from May 1 to Oct. 31 “summer” was to maximize energy with the objective
of the reservoir being full on Nov. 1.
Energy losses of 1.5 percent for outages and 2 percent for transformer losses were
applied to the total generation.
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Active storage remained constant over the simulation period. Dead storage in the
reservoir was assumed to be sufficient to contain sedimentation loads.
No ramping rate restrictions were imposed on either reservoir drawdown or downstream
flow.
Key parameters related to energy generation are shown in Table 6 below.
Table 6. Summary of Energy Parameters
Gross Head (ft) 3,340
Net Head
(Max Flow) (ft)
3,185.2
Maximum Plant Flow (cfs) 20
Number of Units 1
Nameplate Capacity (MW) 4.9
Maximum Pool Elevation (ft) 3,360
Minimum Pool Elevation (ft) 3,340
Tailwater Elevation
(Max Flow) (ft)
20
Usable Storage
(acre-ft)
5,476
7.1 Model Operation
Daily inflow data was used to determine the facility’s ability to meet a winter energy production
target and maximize summer generation. For each day from November through April the flow
through the powerhouse was limited to the amount necessary to satisfy a prescribed capacity
demand given the available head, environmental flow constraints, and reservoir operational
restrictions. During the months of May through September energy production each day was
maximized if the reservoir elevation was above the target rule curve. If the reservoir elevation
was below the target rule curve then generation was limited. The simulation was repeated at
various increasing winter load demands until the maximum firm capacity was determined.
7.2 Results
Using the above assumptions, the resulting average annual energy is estimated to 37,100 MWh
with a 100% dependable winter capacity of 3.8 MW (16,600 MWh). The detailed results can be
found in Appendix B.
7.3 Sensitivity Analysis
The energy analysis above assumes certain base case conditions. To better quantify the effects
of different input assumptions, a sensitivity analysis was performed on the assumed winter
inflow conditions, overall hydrology assumptions, storage and the reliability of the winter firm
load as described below.
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7.3.1 Winter Inflow
Correlating hydrology to the Dorothy Lake gage results in inflows during the winter months of
Nov-April. These flows amount to approximately 6% of the annual yield of the system. Due to
Schubee Lake being approximately 150 miles north, winter precipitation might fall as snow and
not as runoff into the lake. The subsequent runoff in the summer due to this snowfall might go
as spill. The effect of this would be to decrease annual energy to 34,700 MWh (-7%) and
dependable winter capacity to 3.4 MW (-13%).
7.3.2 Overall Hydrology
As noted above the precipitation in the region can vary significantly depending upon location.
To evaluate the effect of lower than predicted runoff, the daily flow files in the synthetic period
of record were scaled by 75%. The effect of this would be to decrease annual energy to 35,200
MWh (-6%) and the dependable winter capacity to 3.4MW (-13%).
7.3.3 Storage
The base case analysis assumes utilization of 5,476 AF of storage between the elevations of
3,360 and 3,340. Assuming the lake could be drawn down an additional 10 feet by deepening
the siphon intake or a lake tap, the annual energy would increase to 38,800 MWh (4%) and the
dependable winter capacity to the installed capacity of 4.9 MW (26%).
7.3.4 Environmental Flow Release
The base case assumes that no flow releases would be required in Schubee Creek for either
fishery or visual resources. However, the USFS has required an aesthetic flow release at the
nearby Goat Lake hydroelectric project. Since the Schubee Lake project is similar in nature to
the Goat Lake project, a licensing condition of the USFS could be an aesthetic flow release.
Assuming a 4 cfs average daily release into Schubee Creek during the months of May through
September, the average annual energy would decrease to 36,800 MWh.
7.3.5 Firm Winter Capacity
To better quantify the effect of low water years on the firm winter capacity, winter load levels in
excess of the firm capacity were also evaluated. The results of this analysis are expressed as a
capacity at a given percent exceedance level. The resulting firm capacity and average annual
energy production estimates are summarized in Table 7.
Table 7: Firm Capacity and Energy Estimate
Firm Winter
Capacity (MW) Dependability Average Annual Energy
Production (MWh)
4.25 97% 37,600
4.50 92% 37,400
4.75 87% 37,300
4.90 87% 37,300
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8 Cost Estimates
An opinion of probable construction costs was derived for the project configuration presented
above. Cost information detail is included in Appendix C. The approach used was to develop
base work units and unit prices and then apply these units and prices consistently to the various
alternatives.
The following assumptions were used in the cost estimate:
Submarine cable unit costs were taken from the recently released Southeast Alaska
Integrated Resource Plan. Termination unit costs were estimated by AP&T.
Indirect construction costs associated with engineering, construction management,
licensing, permitting and the owner’s internal costs were added to the direct construction
cost estimate as either percentages or lump sum amounts.
A lump sum value of $1,000,000 was assumed to provide environmental baseline studies
in support of the FERC licensing application and preparation of the FERC licensing
application and any necessary permits.
The Owner’s General Administration and Overhead of the design and construction was
assumed to be 5% of the total direct construction costs.
Construction management was assumed to be 3% of the total direct construction costs.
A contingency of 25% was added to the total of the direct and indirect construction costs
to reflect uncertainties of layout and design that wouldn’t be resolved until later in the
development process.
Interest accrued during a 30-month construction period was assumed to be 5% and was
added to the total of the direct and indirect construction costs.
8.1 Results
The Schubee Lake project is estimated to cost approximately $74.8M as shown in Table 8 below.
A detailed cost estimate can be found in Appendix C.
Schubee Lake Hydroelectric Project
Reconnaissance Report
19
Table 8 - Opinion of Probable Cost
330 LAND AND LAND RIGHTS $ 90,000
331 STRUCTURES AND IMPROVEMENTS $ 690,000
332 RESERVOIRS, DAMS AND WATERWAYS $ 23,555,000
333 WATERWHEELS, TURBINES AND GENERATORS $ 5,000,000
334 ACCESSORY ELECTRICAL EQUIPMENT $ 230,000
335 MISC. POWER PLANT EQUIPMENT $ 35,000
336 ROADS, RAILROADS AND BRIDGES $ 100,000
350 LAND AND LAND RIGHTS $ 50,000
352 STRUCTURES AND IMPROVEMENTS
(TRANSMISSION FACILITY) $ 35,000
353 STATION EQUIPMENT $ 105,000
356 CONDUCTORS & DEVICES $ 19,900,000
397 COMMUNICATION AND CONTROL EQUIPMENT $ 100,000
TOTAL DIRECT CONSTRUCTION COST $ 49,890,000
Contingency $ 12,475,000
Design Engineering $ 1,497,000
Geotechnical $ 1,497,000
Licensing & permitting $ 1,000,000
Owner's General Administration & overhead $ 2,495,000
Construction Management $ 1,497,000
Interest During Construction $ 4,421,000
TOTAL PROJECT COSTS $ 74,772,000
9 Environmental Considerations
The development of any hydroelectric project requires the consideration of various
environmental issues. This section provides a brief reconnaissance level assessment of several of
these issues. This assessment is based upon a field visit and literature review. HDR did not
conduct any detailed field investigations.
9.1 Fish Resources
The ADF&G maintains two databases that house spatially-referenced fish presence data
collected throughout the state: the Anadromous Waters Catalog (AWC) and the Alaska
Freshwater Fish Inventory Database (AFFID). The AWC is the regulatory tool established by
statute [AS 16.05.871(a)] to specify the various rivers, lakes and streams in Alaska that are
important to the spawning, rearing, or migration of anadromous fish (ADF&G 2011). The
AFFID houses occurrence data for both anadromous and resident freshwater fish compiled from
a variety of sources. Neither the AWC nor the AFFID list data collection points within the
Schubee Lake system or adjacent streams within Taiya Inlet.
Schubee Lake Hydroelectric Project
Reconnaissance Report
20
Resident fish species, such as Dolly Varden, have been captured upstream of large waterfalls in
numerous systems throughout Alaska. Therefore, it is possible that the Schubee Creek could
support a resident fish population although it is probably unlikely.
9.2 Visual Impact
The project features as described would have a minimal visual projection. However, any road or
above ground construction would likely create a very large visual impact. Additionally, the
dewatering of Schubee Creek would eliminate the series of cascading waterfalls which might be
considered an aesthetic resource and therefore there would be a visual impact.
9.3 Water Quality
Project operations should not have an adverse affect on water quality. However, underground
excavation will require the disposal of excavated materials in Taiya Inlet. There could be
localized impacts to water quality due to this.
9.4 Recreation
Lands in the project area are undeveloped and with no access it is highly unlikely that any
recreation exists within the project area.
9.5 Subsistence, Cultural and Historical Resources
It is unlikely that the project area would be the source of any cultural or historical resources, or
used for subsistence hunting.
9.6 Land Ownership, Mining Claims, and Water Rights
HDR real estate specialists performed an initial research of public land, private holdings and
mineral claims. All lands appear to be owned by the U.S. Forest Service and there are no
recorded mineral claims. The project area has a USFS land use designation of Semi-Remote
Recreation.
The Alaska Land Records Database online (http://dnr.alaska.gov/Landrecords/) was accessed on
December 15, 2011 to review the proposed location for the Schubee Lake Hydroelectric Project
for existing water rights or other relevant land status information. There are no existing or
proposed water rights in the vicinity of the proposed Schubee Lake Hydroelectric Project,
located in the northwest quarter of Section 16, Township 29 South, Range 60 East, Copper River
Meridian. There are no state land classifications or other state authorizations in the vicinity of
the Lake or outflow of the lake.
10 Licensing/Permitting
Due to the lands being owned by the USFS, the project would be subject to FERC jurisdiction.
Since the project as proposed will not incorporate roads, the USFS’s Roadless Rule should not be
a major licensing factor. Based upon the cursory review of environmental considerations, the
visual impact of the project and disposal of excavated materials will likely be the largest
environmental issues.
Schubee Lake Hydroelectric Project
Reconnaissance Report
21
11 Conclusions and Recommendations
Construction and operation of the Schubee Lake project would be extremely difficult due to lack
of road access. All construction and operation would be via boat and helicopter. At about
$15,300 per kW the project is expensive by today’s standards. This expense is driven by the
difficult access, the need for a submarine transmission line and the amount of underground
construction required. The underground construction component of the project also provides an
additional element of cost containment risk. At the referenced project capacity, the project
would have an estimated annual energy generation capability of 37,100 MWh with 16,600 MWh
of firm winter capacity. This is sufficient energy to meet even the highest load growth case
presented in the Southeast Alaska Integrated Resource Plan. However, due to the existing hydro
resources in the interconnected Upper Lynn Canal region, the project could be underutilized for
much of its initial life.
The installed capacity of the project could be increased to approximately 9.5 MW in order to
fully utilize all the water. This would result in approximately 50,000 MWh of energy with the
increase coming in the late summer months. However, at present there does not appear to be
demand for this additional energy.
Future near term development efforts should include a bathymetric survey of the lake to confirm
the available storage and in the vicinity of the powerhouse to assess the suitability for a
permanent marine landing.
Additionally geotechnical work should be performed to confirm the suitability of site to
underground construction and the properties of the terminal moraine controlling the lake outlet.
Considerable leakage occurs apart from the natural lake outlet. As such, the normal lake level
may have to be lowered in order to stop this leakage to conserve water. This would cause a
neglible effect to the energy estimates provided within this report. Geotechnical investigations
should also address the suitability of pressurizing the tunnel. Favorable rock conditions could
result in a reduction of the length of penstock required.
The siphon intake proposed has the least capital cost of all the intake options. However, a siphon
intake can present significant operation and maintenance expenses and difficulties. A lake tap
would provide additional operational flexibility and allow more storage to be used in low flow
conditions but has a higher initial construction costs and geotechnical risk. Once geotechnical
conditions are known, an updated cost/benefit analysis should be made on the intake type.
Diversion of water from Schubee Creek to Kasidaya Creek is less desirable than developing the
base case scenario. The savings from elimination of the submarine cable are offset by the
increased costs associated with more underground work. Additionally, the water from Schubee
Creek would only be of value during the winter since more than adequate flow exists in Kasidaya
Creek during the summer months.
An insufficient amount of site specific hydrological data exists for the project. Gage data from
nearby gages shows high variability in average runoff data depending upon locale. As such,
actual conditions at Schubee Lake could vary significantly from what has been initially assumed.
As additional site specific runoff data is obtained, the appropriateness of the hydrologic
assumptions and corresponding energy estimates used in this report should be reviewed.
Appendix A
A world ofcapabilities
delivered locally
GEOTECHNICAL
RECONNAISSANCE
SCHUBEE LAKE
HYDROELECTRIC PROJECT
Haines, Alaska
Submitted To:
Submitted By:
Distribution:
October 31, 2011 113-95725REPORT
Table of Contents
List of Figures
List of Figures
1.0 INTRODUCTION
2.0 METHODOLOGY
3.0 SITE CONDITIONS
3.1 General Geology and Topography
3.2 Lake Outlet
3.3 Powerhouse Location
3.4 Tunnel Conduits
3.5 Surface Penstock
4.0 CONCLUSIONS AND RECOMMENDATIONS
4.1 Lake Outlet
4.2 Powerhouse
4.3 Water Conduit Options
4.4 Geologic Hazards
4.4.1 Seismic Hazards
5.0 COST IMPLICATIONS
6.0 LIMITATIONS AND USE OF REPORT
8.0 REFERENCES
FIGURES
SKAGWAY
HAINES
PROJECT LOCATION
CHECK
REVIEW
DESIGN
CADD
SCALE
FILE No.
PROJECT No.
TITLEAS SHOWN
REV.
SCALE
0
MILES
2.52.5
1
NA ----
DBC 10/7/11
RGD 10/7/11
RGD 10/7/11
0 ----
FIG.
113-95725
Shubee_UTM-6-NA83ft.dwg
HDR / SCHUBEE LAKE / AK
VICINITY MAP
SCHUBEE LAKE HYDRO
SCHUBEE LAKE, ALASKA
PROJECT LOCATION
1.) TOPOGRAPHIC MAP PROVIDED BY U.S.G.S. SKAGWAY (A-1)SW,
ALASKA, PROVISIONAL EDITION 1991
REFERENCES
CHECK
REVIEW
DESIGN
CADD
SCALE
FILE No.
PROJECT No.
TITLEAS SHOWN
REV.J:\2011 Jobs\113-95725 HDR Shubee Lake Hydro\CAD\Shubee_UTM-6-NA83ft.dwg | 10/7/2011 3:37 PM | DCutter | ANCHORAGE, ALASKA
3
NA ----
DBC 10/7/11
RGD 10/7/11
RGD 10/7/11
0 ----
FIG.
113-95725
Shubee_UTM-6-NA83ft.dwg
HDR / SCHUBEE LAKE / AK
PHOTOGRAPHS OF LAKE AT OUTLET
AND WESTERN SHORELINE
SCHUBEE LAKE HYDRO
SCHUBEE LAKE, ALASKA
PHOTO: VIEW TO THE NORTHEAST
PHOTO: VIEW TO THE SOUTH OVER MORAINE
OUTLET
GLACIER
OUTLET
MORAINE
CHECK
REVIEW
DESIGN
CADD
SCALE
FILE No.
PROJECT No.
TITLEAS SHOWN
REV.J:\2011 Jobs\113-95725 HDR Shubee Lake Hydro\CAD\Shubee_UTM-6-NA83ft.dwg | 10/7/2011 4:07 PM | DCutter | ANCHORAGE, ALASKA
4
NA ----
DBC 10/7/11
RGD 10/7/11
RGD 10/7/11
0 ----
FIG.
113-95725
Shubee_UTM-6-NA83ft.dwg
HDR / SCHUBEE LAKE / AK
PHOTOGRAPHS OF LAKE OUTLET AND
FAULT TROUGH
SCHUBEE LAKE HYDRO
SCHUBEE LAKE, ALASKA
PHOTO: VIEW NORTHWARD ACROSS OUTLET AND MORAINE
PHOTO: VIEW SOUTHWARD ALONG WEST SIDE OF LAKE.
MORAINE
OUTLET
FAULT TROUGH
FILLED WITH TALUS
CHECK
REVIEW
DESIGN
CADD
SCALE
FILE No.
PROJECT No.
TITLEAS SHOWN
REV.J:\2011 Jobs\113-95725 HDR Shubee Lake Hydro\CAD\Shubee_UTM-6-NA83ft.dwg | 10/7/2011 3:42 PM | DCutter | ANCHORAGE, ALASKA
5
NA ----
DBC 10/7/11
RGD 10/7/11
RGD 10/7/11
0 ----
FIG.
113-95725
Shubee_UTM-6-NA83ft.dwg
HDR / SCHUBEE LAKE / AK
PHOTOGRAPHS OF BEDROCK SLOPE
ALONG WESTERN SHORELINE
SCHUBEE LAKE HYDRO
SCHUBEE LAKE, ALASKA
PHOTO: VIEW TO THE WEST
PHOTO: VIEW TO THE WEST, NOTE BEDROCK DIPPING TO THE LAKE
CHECK
REVIEW
DESIGN
CADD
SCALE
FILE No.
PROJECT No.
TITLEAS SHOWN
REV.J:\2011 Jobs\113-95725 HDR Shubee Lake Hydro\CAD\Shubee_UTM-6-NA83ft.dwg | 10/14/2011 8:50 AM | DCutter | ANCHORAGE, ALASKA
6
NA ----
DBC 10/14/11
RGD 10/14/11
RGD 10/14/11
0 ----
FIG.
113-95725
Shubee_UTM-6-NA83ft.dwg
HDR / SCHUBEE LAKE / AK
PHOTOGRAPHS OF POTENTIAL
POWERHOUSE SITES
SCHUBEE LAKE HYDRO
SCHUBEE LAKE, ALASKA
PHOTO: VIEW NORTHWARD
PHOTO: VIEW SOUTHWARD
POWERHOUSE
OPTION B
POWERHOUSE
OPTION A
POWERHOUSE
OPTION A
CHECK
REVIEW
DESIGN
CADD
SCALE
FILE No.
PROJECT No.
TITLEAS SHOWN
REV.J:\2011 Jobs\113-95725 HDR Shubee Lake Hydro\CAD\Shubee_UTM-6-NA83ft.dwg | 10/7/2011 4:10 PM | DCutter | ANCHORAGE, ALASKA
7
NA ----
DBC 10/7/11
RGD 10/7/11
RGD 10/7/11
0 ----
FIG.
113-95725
Shubee_UTM-6-NA83ft.dwg
HDR / SCHUBEE LAKE / AK
VIEWS OF SLOPES BELOW THE LAKE
SCHUBEE LAKE HYDRO
SCHUBEE LAKE, ALASKA
PHOTO: OVERVIEW OF SLOPE
PHOTO: EXPOSED BEDROCK BELOW LAKE
LAKE OUTLET
POWERHOUSE
OPTION B
SCHUBEE CREEK
SCHUBEE CREEK
SCHUBEE
ELEVATION (FT)A'HORIZONTAL DISTANCE (FT)A-500400800120016002000240028003200360040000 1000 2000 3000 4000 5000 6000 70001234VERTICALBOREHOLEOPTIONCONCEPTUALTUNNELLOCATIONANGLED ORDIRECTIONALLY DRILLEDBOREHOLE OPTIONLAKEPOWERHOUSESITEOPTION AJ:\2011 Jobs\113-95725 HDR Shubee Lake Hydro\CAD\Shubee_UTM-6-NA83ft.dwg | 10/13/2011 11:22 AM | DCutter | ANCHORAGE, ALASKASCALE0FEET100010008NA ----DBC 10/13/11RGD 10/13/11RGD 10/13/110 ----FIG.113-95725Shubee_UTM-6-NA83ft.dwgHDR / SCHUBEE LAKE / AKOPTION A CONCEPTUALSUBSURFACE CONDUITSSCHUBEE LAKE HYDRO SCHUBEE LAKE, ALASKACHECKREVIEWDESIGNCADDSCALEFILE No.PROJECT No.TITLEAS SHOWNREV.
APPENDIX A
EXCERPTS FROM MAPPED AVALANCHE PATHS
Golder Associates Inc.
2121 Abbott Road, Suite 100
Anchorage, AK 99507 USA
Tel: (907) 344-6001
Fax: (907) 344-6011
Appendix B
SCHUBEE.OUT ---------------------------------------------------------------------------------------------------------------------------- Schubee Lake POWER GENERATION ----------------------------------------------------------------------------------------------------------------------------DATA FILE USED: Schubee.QCHMODEL DESCRIPTION-----------------PIPE # LENGTH DIAMETER MANNING'S n MINOR LOSSES 1 500 24 .01 1 2 3800 30 .015 .5 3 6500 18 .01 .5 MAX POOL ELEV : 3360 MIN POOL ELEV : 3340 DESIGN FLOW: 20 GROSS HEAD: 3340 NET HEAD @ FULL LOAD: 3185.2NAMEPLATE CAPACITY (MW): 4.9 @ 1 POWER FACTORTARGET FIRM CAPACITY (MW): 3.80STATION SERVICE LOSS: 0 TRANSFORMER LOSS: 2 TRANSMISSION LOSS: 0 SCHEDULED DOWN TIME: 1.5 RESERVOIR STAGE / STORAGE 3260 0 3270 2001 3280 4085 3290 6253 3300 8506 3310 10845 3320 13271 3330 15785 3340 18387 3350 21079 3360 23863USABLE STORAGE: 5476 SIMULATED PRODUCTION IN MEGAWATT-HOURS YEAR OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP TOTAL ----------------------------------------------------------------------------------------------------------------------------------------- 1987 3,537 2,740 2,831 2,831 2,557 2,831 2,739 3,517 3,406 3,529 3,537 3,423 37,478 1988 3,537 2,740 2,831 2,831 2,648 2,831 2,739 3,518 3,406 3,527 3,537 3,423 37,567 1989 3,537 2,740 2,831 2,831 2,557 2,831 2,739 3,516 3,408 3,532 3,537 3,423 37,481 1990 3,536 2,740 2,831 2,831 2,557 2,831 2,739 3,517 3,408 3,533 3,537 3,423 37,484 1991 3,536 2,740 2,831 2,831 2,557 2,831 2,739 3,175 3,405 3,530 3,537 3,423 37,135 1992 3,537 2,740 2,831 2,831 2,648 2,831 2,739 3,517 3,409 3,535 3,537 3,423 37,578 1993 3,536 2,740 2,831 2,831 2,557 2,831 2,739 3,402 3,408 3,529 3,536 3,423 37,361 1994 3,537 2,740 2,831 2,831 2,557 2,831 2,739 3,519 3,408 3,532 3,537 3,423 37,485 1995 3,537 2,740 2,831 2,831 2,557 2,830 2,739 3,401 3,406 3,527 3,536 3,423 37,357 1996 3,537 2,740 2,831 2,831 2,648 2,830 2,739 1,814 3,404 3,526 3,534 3,423 35,857 1997 3,536 2,740 2,831 2,831 2,557 2,831 2,739 3,516 3,407 3,531 3,537 3,423 37,479 1998 3,536 2,740 2,831 2,831 2,557 2,831 2,739 3,175 3,407 3,529 3,536 3,423 37,133 1999 3,537 2,740 2,831 2,831 2,557 2,831 2,739 3,062 3,405 3,529 3,537 3,423 37,021 2000 3,536 2,740 2,831 2,831 2,648 2,831 2,739 3,517 3,405 3,530 3,537 3,423 37,568 2001 3,537 2,740 2,831 2,831 2,557 2,831 2,739 2,722 3,291 3,528 3,537 3,423 36,565 2002 3,536 2,740 2,831 2,831 2,557 2,830 2,739 1,474 3,407 3,533 3,537 3,423 35,438AVERAGE 3,537 2,740 2,831 2,831 2,580 2,831 2,739 3,148 3,399 3,530 3,537 3,423 37,124AVG CAP 4.75 3.81 3.81 3.80 3.80 3.80 3.80 4.23 4.72 4.74 4.75 4.75 4Page 1
SCHUBEE.OUTTARGET CAPACITY EXCEEDANCE: 100.0%AVERAGE PLANT FACTOR: 0.89 BEGINNING RESERVOIR ELEVATIONS YEAR OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP ---------------------------------------------------------------------------------------------------------------------------- 1987 3360.0 3359.8 3358.2 3355.6 3352.9 3350.1 3346.8 3343.7 3341.4 3347.7 3358.8 3360.0 1988 3360.0 3359.6 3358.0 3355.3 3352.3 3349.6 3346.6 3343.6 3342.0 3347.8 3356.9 3359.9 1989 3360.1 3359.2 3356.5 3354.4 3351.4 3348.5 3345.2 3342.0 3341.3 3350.0 3360.0 3360.1 1990 3360.1 3358.5 3356.9 3354.9 3352.2 3349.4 3346.4 3343.5 3341.9 3351.4 3360.0 3360.1 1991 3360.0 3358.6 3355.8 3353.0 3349.9 3347.4 3344.3 3341.3 3340.3 3348.7 3359.6 3360.1 1992 3360.1 3359.3 3356.7 3354.0 3351.1 3348.5 3346.3 3343.5 3342.2 3352.5 3360.0 3360.1 1993 3360.1 3358.0 3355.8 3352.9 3349.8 3347.4 3344.3 3341.2 3341.6 3349.2 3356.4 3360.1 1994 3360.1 3360.1 3358.5 3355.8 3352.8 3350.0 3347.0 3344.4 3343.5 3350.3 3360.1 3360.1 1995 3360.1 3359.0 3356.3 3353.2 3350.0 3347.1 3343.7 3340.8 3340.8 3347.3 3355.2 3360.1 1996 3360.1 3358.8 3355.9 3352.8 3349.8 3346.8 3343.7 3340.6 3340.1 3345.8 3353.5 3360.0 1997 3360.1 3358.9 3356.9 3354.0 3350.8 3348.0 3344.9 3342.0 3341.5 3349.3 3360.1 3360.1 1998 3360.1 3358.5 3356.2 3353.9 3350.8 3347.8 3344.5 3341.4 3340.9 3348.7 3356.3 3360.0 1999 3360.1 3360.0 3357.3 3354.2 3351.3 3348.4 3345.1 3342.1 3340.1 3347.5 3358.8 3360.1 2000 3360.0 3359.7 3357.2 3355.5 3352.9 3350.0 3346.8 3343.8 3340.8 3347.6 3360.0 3360.1 2001 3360.1 3359.1 3357.0 3354.2 3351.4 3348.6 3345.4 3342.2 3340.0 3345.9 3357.9 3360.0 2002 3360.1 3358.2 3355.4 3352.4 3349.4 3346.6 3343.3 3340.0 3340.5 3351.3 3360.1 3359.8 ---------------------------------------------------------------------------------------------------------------------------- TARGET 3340.0 3355.0 3350.0 3347.5 3345.0 3342.5 3340.0 3340.0 3340.0 3340.0 3340.0 3340.0 MIN 3320.0 3320.0 3320.0 3320.0 3320.0 3320.0 3320.0 3320.0 3320.0 3320.0 3320.0 3320.0 AVG 3360.1 3359.1 3356.8 3354.1 3351.2 3348.4 3345.3 3342.3 3341.2 3348.8 3358.4 3360.0 START POOL ELEV: 3360.0 ENDING POOL ELEV: 3360.1 MIN. POOL ELEV: 3339.9 MAY 9, 2002STORAGE CHANGE (CFS): 0.0 MONTHLY FLOW INFORMATION OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP AVG ---------------------------------------------------------------------------------------------------------------------------------- AVG INFLOW 20.7 4.9 3.6 2.3 2.2 2.0 2.2 13.2 54.5 67.8 65.9 52.1 24.4 MIF 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 SPILL 5.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.8 38.3 32.0 6.7 DS POWERHOUSE 20.0 15.7 15.7 15.7 15.8 15.7 15.7 17.9 20.0 20.0 20.0 20.0 17.7THIS SIMULATION USED THE FOLLOWING EQUIPMENT EFFICIENCIES % CAP TURBINE GENERATOR COMBINED ---------------------------------------- 0 0.0 0.0 0.0 5 30.0 0.0 0.0 10 80.0 92.8 74.2 15 84.0 93.9 78.9 20 88.0 94.9 83.6 25 88.7 95.7 84.9 30 89.5 96.3 86.2 35 89.8 96.7 86.9 40 90.2 97.0 87.5 45 90.0 97.2 87.5 50 89.8 97.3 87.4 55 90.1 97.4 87.8 60 90.4 97.5 88.2 65 90.5 97.6 88.4 70 90.6 97.7 88.5Page 2
SCHUBEE.OUT 75 90.6 97.7 88.5 80 90.5 97.7 88.4 85 90.4 97.7 88.4 90 90.4 97.7 88.4 95 90.3 97.7 88.2 100 90.2 97.7 88.1Page 3
Appendix C
Item Quantity Unit Unit Cost Amount
330 LAND AND LAND RIGHTS
.1 Land Rights - Generation Plant 0 LS 50,000$ -$
.2 Special use permits 1 LS 50,000$ 50,000$
.3 Surveying 1 LS 40,000$ 40,000$
331 STRUCTURES AND IMPROVEMENTS
.1 POWERHOUSE
.1 Excavation 4500 CY 75$ 337,500$
.2 Concrete (incl. reinforcement) 65 CY 1,500$ 97,500$
.3 Metal Building 1200 SF 150$ 180,000$
.4 Misc. Metals 1 LS 5,000$ 5,000$
.5 HVAC, Plumbing & Electrical 1 LS 50,000$ 50,000$
.6 Grounding Grid 1 LS 10,000$ 10,000$
.7 Fire Protection 1 LS 10,000$ 10,000$
332 RESERVOIRS, DAMS AND WATERWAYS
.1 SITE WORK
.1 Clearing/Drainage/Erosion Control 1 LS 10,000$ 10,000$
.2 INTAKE
.1 Excavation 1 LS 60,000$ 60,000$
.2 Intake Screens 1 LS 10,000$ 10,000$
.3 HDPE Pipeline 250 LF 50$ 12,500$
.4 Shutoff Valve w/operator 1 LS 10,000$ 10,000$
.5 Valve House 1 LS 10,000$ 10,000$
.6 Electrical & mechanical equipment 1 LS 75,000$ 75,000$
.3 WATER CONDUCTORS AND ACCESSORIES
.1 PENSTOCK
.a 8' Horseshoe tunnel 6500 FT 1,500$ 9,750,000$
.b Shaft 3700 FT 1,800$ 6,660,000$
.c Lower Portal 1 LS 150,000$ 150,000$
.d Lining 250 FT 5,000$ 1,250,000$
.e Reinforcement/rock bolts 250 FT 1,000$ 250,000$
.f Upper Shaft Portal 1 LS 250,000$ 250,000$
.g Penstock material 6500 FT 500$ 3,250,000$
.h Penstock installation 6500 FT 250$ 1,625,000$
.i Thrust blocks 50 CY 2,500$ 125,000$
.j Supports 500 FT 100$ 50,000$
.4 TAILRACE
.a Excavation 1 LS 5,000$ 5,000$
.b Support and lining 1 LS 2,500$ 2,500$
333 WATERWHEELS, TURBINES AND GENERATORS
.1 Supply 4900 kW 1,000$ 4,900,000$
.2 Install 1 LS 100,000$ 100,000$
334 ACCESSORY ELECTRICAL EQUIPMENT
.1 Switchgear 1 LS 75,000$ 75,000$
.2 Station Service 1 LS 30,000$ 30,000$
.4 PLC Controls, Panel, and Generator Wiring 1 LS 100,000$ 100,000$
.5 Conduit/wires/cables 1 LS 25,000$ 25,000$
335 MISC. POWER PLANT EQUIPMENT
.1 Cooling Water System 1 LS 25,000$ 25,000$
.2 Powerhouse crane rail 1 LS 10,000$ 10,000$
336 ROADS, RAILROADS AND BRIDGES
.1 Marine landing 1.0 LS 100,000$ 100,000$
350 LAND AND LAND RIGHTS
.1 Land rights - transmission line 1 LS 50,000$ 50,000$
352
STRUCTURES AND IMPROVEMENTS
(TRANSMISSION FACILITY)
.1 Substation foundations 1 LS 10,000$ 10,000$
.2 Oil spill containment 1 LS 10,000$ 10,000$
.3 Grounding grid 1 LS 15,000$ 15,000$
353 STATION EQUIPMENT
.1 Generator Step-up Transformer 1 LS 75,000$ 75,000$
.2 Disconnects 3 LS 10,000$ 30,000$
356 CONDUCTORS & DEVICES
.1 Submarine Transmission Line 9.00 MI 2,100,000$ 18,900,000$
.2 Terminations 2.00 EA 500,000$ 1,000,000$
397 Communication and Control Equipment
.1 Telemetry and Communications Equipment 1.0 LS 100,000$ 100,000$
Total Direct Construction Costs 49,900,000$
Contingency 25% 12,475,000$
Design Engineering 3% 1,497,000$
Geotechnical 3% 1,497,000$
Licensing & permitting 1,000,000$
Owner's General Administration & overhead 5% 2,495,000$
Construction Management 3% 1,497,000$
Subtotal 70,361,000$
Interest During Construction 5% 30 months 4,421,000$
Total 74,782,000$
Schubee Lake Hydroelectric Project
OPINION OF PROBABLE COST