HomeMy WebLinkAboutAllison Creek Final Feasibility Study Addendum 2011~HATCH~ Hatch Acres Corporation
6 Nickerson Street, Suite 101, Seattle, WA 98109 USA
Tel: 206-352-5730 • Fax: 206-352-5734 • www.hatchusa.com
Robert A. Wilkinson, CEO january 10, 2011
H-327730 Copper Valley Electric Association
P.O. Box 45
Glennallen, AK 99588-2832
Dear Robert: Subject: Allison Creek Hydroelectric Project
Final Feasibility Study -Addendum
We are pleased to submit herewith our Addendum to the Final Feasibility Study (FFS) for the Allison Lake Hydroelectric
Project. The FFS presented our analysis of six technically feasible arrangements for the project. This Addendum
presents our analysis of two additional options for the project. Together these documents comprise the results of
Hatch's study of the feasibility for hydropower development of the Allison Creek basin.
• Alternative 4a (Ait 4a): A run-of-river development on Allison Creek commencing approximately 2,000
downstream of the outlet of Allison Lake consisting of a diversion structure and a penstock leading to a 6.5
MW powerhouse at the same location as considered for Alt 3c.
• Alternative 4b (Ait 4b): The addition of an inflatable gate on the Solomon Gulch Spillway that would raise the
normal maximum water surface of Solomon Lake by five feet.
Our principal conclusions for these two alternatives as stated within the report include:
• Alternative 4a
A run-of-river Alt 4a development of the Allison Creek basin is not cost effective with operation within
the Copper Valley Electric Association, Inc.'s (CVEA) existing system load.
With the addition of 2 MW to the CVEA system load, the project would be competitive with the cost of
diesel generation.
The reduced scale of the hydropower development of the Allison Creek basin as offered by Alt 4a would
reduce the risk of construction cost overruns, seepage and dam safety concerns and environmental
impacts as compared to Alt 3c.
Alt 4a is superior to Alt 3c in all respects.
• Alternative 4b
The addition of inflatable gates to the Solomon Gulch Spillway as proposed for Alt 4b would add
approximately 2 GWh of energy to the CVEA system.
The addition of inflatable gates to the Solomon Gulch Spillway as proposed for Alt 4b would require
amendment to existing FERC License for the Solomon Gulch Project.
On the basis of the energy potential and cost estimates prepared for this evaluation, Alt 4b currently
would not be an economically viable project.
Based on these conclusions we recommend that the CVEA adopt Alt 4a as the preferred alternative for the development
of the hydroelectric potential of the Allison Creek basin and that further consideration of Alt 3c and Alt 4b be
terminated.
We greatly appreciate the opportunity to work with you on this interesting project. If you have any questions regarding
the subject report, be sure to give us a call.
Yours very truly,
A. Richard Griffith, P.E.
Project Manager
The Energy Company
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
Table of Contents
1. Introduction ............................................................................................................................................ 1
1.1 General .......................................................................................................................................... 1
1.2 Alternative 4 -General Arrangement ............................................................................................. 2
1.3 Alternative 4a-Diversion Structure on Allison Creek with Penstock leading to
Powerhouse (A It 4a) ....................................................................................................................... 3
1.4 Alternative 4b-Raising Solomon Gulch Reservoir Maximum Water Surface 5 feet with
Inflatable Gates on Spillway (Ait 4b) .............................................................................................. 4
2. Power Studies .......................................................................................................................................... 6
2.1 Unconstrained Run-of-River Operation .......................................................................................... 6
2.2 System Loads and Resources .......................................................................................................... 7
2.2.1 System Loads ........................................................................................................................ 7
2.2 .2 System Resources ................................................................................................................. 7
2.3 AUTO Vista Model: Allison Creek Run-of-River Hydropower Development ................................... 8
2.4 Hydrology ...................................................................................................................................... 8
2.5 Hydro Equipment Characteristics ................................................................................................... 9
2.6 AUTO Vista Results ........................................................................................................................ 9
3. Project Construction Cost and Construction Schedule .......................................................................... 13
3.1 Construction Cost Estimates ......................................................................................................... 13
3 .1.1 Alternative 4a ..................................................................................................................... 13
3 .1.2 Alternative 4b ..................................................................................................................... 14
3.2 Construction Schedule ................................................................................................................. 15
3.3 Economic Analysis ....................................................................................................................... 16
3.3.1 Cost of Power-Alternative 4a ........................................................................................... 17
3.3.2 Cost of Power-Alternative 4b ........................................................................................... 18
4. Regulatory and Environmental Considerations ...................................................................................... 20
4.1 Alternative 4a ............................................................................................................................... 20
4.1.1 Regulatory Considerations .................................................................................................. 20
4.1.2 Environmental Field Investigations ..................................................................................... 21
4.1.3 Environmental Considerations ............................................................................................ 22
4.2 Alternative 4b .............................................................................................................................. 22
4.2.1 Regulatory Considerations .................................................................................................. 22
4.2.2 Environmental Field Studies ............................................................................................... 22
4.2.3 Environmental Considerations ............................................................................................ 23
5. Conclusions and Recommendations ...................................................................................................... 24
5.1 Conclusions ................................................................................................................................. 24
5.1.1 Alternative 4a ..................................................................................................................... 24
5.1.2 Alternative 4b ..................................................................................................................... 24
5.2 Recommendations ....................................................................................................................... 25
6. References ............................................................................................................................................. 26
january 2011 Page i
~HATCH~ Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
Tables
Table 1.1
Table 2.1
Table 2.2
Table 2.3
Table 2.4
Table 2.5
Table 2.6
Table 2.7
Table 2.8
Table 3.1
Table 3.2
Table 3.3
Table 3.4
Table 3.5
Table 3.6
Table 4.1
Figures
Figure 1.1
Figure 1.2
Figure 1.3
Figure 1.4
Figure 1.5
Figure 2.1
Figure 2.2
Figure 2.3
Figure 2.4
Figure 3.3
FFS -Design and Economic Conditions .................................................................................. 1
AUTO Vista Hydrologic Years ................................................................................................ 9
Annual Generation -Existing Condition, Loads and Resources ............................................ 10
Annual Generation-Alt 4a w/ Existing Load ........................................................................ 10
Annual Generation-Alt 4b w/ Existing Load ....................................................................... 10
Annual Generation -Existing Resources w/ 2 MW Additional Load ..................................... 11
Annual Generation -Alt 4a w/ 2 MW Additional Load ........................................................ 11
Annual Generation -Alt 4b w/ 2 MW Additional Load ........................................................ 11
Annual Benefits-Alt 4a & 4b ............................................................................................... 12
Alternative 4a-Total Construction Cost (Bid 1/2010) .......................................................... 14
Alternative 4b-Total Construction Cost (Bid 1/2010) ......................................................... 15
Basic Assumptions for Economic Analysis ............................................................................. 16
Alternative 4a-First Year Annual Cost (2010 Dollars) ......................................................... 17
Alternative 4a -Cost of Power ............................................................................................. 18
Alternative 4b -Cost of Power ............................................................................................. 19
Summary of Major Environmental Field Studies ................................................................... 21
Alternative 4 General Arrangement ........................................................................................ 2
Alternative 4a -Plan and Profile ............................................................................................ 3
Diversion Structure-Plan and Cross Section ......................................................................... 4
Typical Obermeyer Gate Installation ...................................................................................... 5
Solomon Gulch Obermeyer Spillway Gate Cross Section ....................................................... 5
Allison Creek Annual Flow-Duration Curve ............................................................................ 6
Allison Average Monthly Distribution of Energy Production .................................................. 7
AUTO Vista Model Elements: Alts 4a and 4b .......................................................................... 8
Allison Powerhouse Unit Characteristics-2 x 3.25 MW Units .............................................. 9
Alternative 4a-Construction Schedule ................................................................................ 16
Appendices
Appendix A -Alternative 4a, System Dispatch
Appendix B -Obermeyer Gate Cost Estimate
january 2011 Page ii
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
1. Introduction
1.1 General
A fundamental premise of the studies leading to the Final Feasibility Study (FFS) for the Allison Lake
Hydroelectric Project (Project) of May 2010 was that an additional hydropower project is needed to
support the Solomon Gulch Project during winter months. Currently the Copper Valley Electric
Association, Inc. (CVEA) must rely on diesel generation to meet system load to make up for the
inability of the Solomon Gulch Project to generate during the winter period. The Allison Creek basin
exhibits the same basic annual pattern of inflow as the Solomon Gulch basin. The 7 months of May
through November are estimated to account for 98% of the annual inflow leaving only a 2%
contribution for the 5 months of December through April. Accordingly, the focus of the FFS was to
determine the most cost-effective manner to mobilize the potential storage capability of Allison Lake
to allow for generation during the low-flow winter-time period. In all, six different schemes, Alt 1,
Alt 2 and Alt 3a through Alt 3d, were reviewed and reported on as part of the previous studies for
the Project. The manner in the proposed design for each alternative provides the necessary storage is
described in Section 1.3 through Section 1.5 of the FFS.
The Project studies have shown that each of the six arrangements are technically and
environmentally feasible. However, the studies also reveal that each arrangement includes
significant challenges potentially affecting their long term economics and/or operational reliability as
listed in Table 1.1.
Table 1.1
Final Feasibility Report
Design and Economic Considerations
Alternative Design and Economic Considerations
Alt 1 Tunnel cost
Alt 2 Tunnel cost
Alt 3a Reliable operation of siphon and maintenance thereof during winter period, access
Alt 3b Drilling of micro-tunnel in glacial moraine
Alt 3c Embankment cost, foundation conditions for embankment, seepage, liquefaction & avalanches, access
Alt 3d Embankment cost, foundation conditions for embankment, seepage, liquefaction & avalanches, access
Subsequent to the completion of the FFS, the range of challenges as summarized above led to a
concern regarding the viability of a storage project within the Allison Creek drainage. However, the
high elevation of the first 2000' below the outlet of Allison Lake suggests that there would be a
significant amount of energy available from Allison Creek as a run-of-river project.
To date, the system load characteristics of CVEA has been such that much of this additional energy
would be stranded; i.e. there would be no load available for the project to serve. Recently, however,
a 2 MW industrial facility has been brought into the CVEA system. This additional load will provide
an opportunity to CVEA to more fully operate a run-of-river project to accommodate what would
otherwise be served by diesel generation.
The purpose of this Addendum to the FFS dated May 2010, is to present the evaluation of the
economic viability of alternative run-of-river arrangements for capturing the hydropower potential of
january 2011 Page 1
..
Copper Valley Electric Association, Inc.-Allison lake Hydroelectric Project
Addendum -Final Feasibility Report
Allison Creek as a project to serve an expanded CVEA system load. This scheme is referred to as Alt
4. The scope of work leading to this Addendum to the FFS has included the following activities:
1. Development of alternative project arrangements consistent with the purposes of this
Addendum.
2. Review of Allison Lake hydrology as related to the run-of-river hydropower potential of the
identified alternatives.
3. Preliminary layout and cost estimate of hydroelectric project features for each of the
identified project arrangements.
4. Economic evaluation of the identified alternatives .
5. Environmental review of the of the identified alternatives.
6. Preparation of this addendum to the Final Feasibility Report including the resulting
conclusions and recommendations.
1.2 Alternative 4 -General Arrangement
The primary features of the run-of-river project selected for this review include the following:
• A low diversion structure on Allison Creek at El. 1300;
• A 42" diameter surface I buried penstock;
• A 6.5 MW powerhouse along Allison Creek at El. 130 with a 1.75 mile transmission line
leading to the Solomon Gulch switchyard; and
• A permanent 1,000 foot access road to the powerhouse and a temporary 4,500 foot trail for
penstock construction access.
The general arrangement of these features for Alt 4 is shown in Figure 1.1. Two versions of Alt 4 are
reviewed herein as described in the following paragraphs.
Figure 1.1
Alternative 4 General Arrangement
january 2011 Page2
Copper Valley Electric Association, Inc.-Allison lake Hydroelectric Project
Addendum -Final Feasibility Report
1.3 Alternative 4a -Diversion Structure on Allison Creek with Penstock leading to
Powerhouse (Ait 4a)
Alt 4a includes the primary features as described above. Plan and profile views of Alt 4a are shown
in Figure 1.2. The general details of the penstock and powerhouse are shown on Figures 8.6 and
8.7 respectively within Appendix B of the FFS. The actual dimensions of the penstock and
powerhouse will be in proportion to the 42~ penstock and 6.5 MW powerhouse as referenced above
for Alt 4 in lieu of the 36H penstock and 4 MW powerhouse for Alt 3c as shown in the FFS.
The access road to the powerhouse as shown in Figure 1.2 will be designed in accordance with the
criteria set forth in Appendix C.3 of the FFS. The design of the access trail from the loop road off the
Trans Alaska Pipeline System corridor to the point where the penstock crosses over a ridge will
follow the same alignment to that point as was studied for the construction access for Alt 3c.
However, the width of the corridor will be reduced consistent with the use of helicopters as the
primary access for construction of the penstock and diversion structure.
Figure 1.2
Alternative 4a -Plan and Profile
PLAN
I Surface I Buried Penstock
~ 1000 ' ;-~~ ~
<:::
0
..... --~ 500
LiJ .....
100 .. .. .. .. .. .. .. .. .. .. .. .. ..
Statlon(ft)
PROFILE
The diversion structure will be located along Allison Creek at approximately El. 1300. The specific
location and type of diversion scheme to be used for the run-of-river option will be determined at the
next level of the design process. A conceptual drawing of the type of diversion structure used for the
present purpose is shown in Figure 1.3.
January 2011 Page3
Figure 1.3
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum -Final Feasibility Report
Diversion Structure -Plan and Cross Section
PLAN
I I
W
I I I I
"' I I "'fJ I
•-&I I
~I I
I I
I I
,.,' I
.... '
10 20 30 40 50 1, l I & I
SCALE IN FEET
I L--_I I Y..,__....._ _ __..lf __ l..,(_......,jo
I I L---------.J SCALE IN FEET
CROSS SECTION
1.4 Alternative 4b-Raising Solomon Gulch Reservoir Maximum Water Surface 5 feet
with Inflatable Gates on Spillway (Ait 4b)
Alt 4b adds additional storage to the Solomon Gulch reservoir by modifying the spillway with 5 foot
high inflatable gates extending the full length ofthe 450 foot long spillway. The proprietary
Obermeyer Gate System, which consists of steel panels that are raised up by inflating a rubber
bladder, has been selected for evaluation of Alt 4b on the basis that the rubber bladder gates without
steel panels are not sufficiently controllable. They must be either in the fully inflated or fully deflated
mode and can release too much water into the tailrace during the transition. The Obermeyer gates
can operate at any stage between up or down thereby controlling water release. A typical
Obermeyer gate installation and proposed profile view of Alt 4b are shown in Figure 1.4 and Figure
1.5, respectively.
January 2011 Page4
Figure 1.4
Typical Obermeyer Gate Installation
Figure 1.5
Copper Valley Electric A ssociation, Inc.-Allison lake Hydroelectric Project
Addendum -Final Feas ibility Re port
Solomon Gulch Obermeyer Spillway Gate Cross Section
TOP OF GATE EL. 690.0
STEEL GATE PANEL SUPPLIED IN NOMINAL
19.56' LENGTHS. (23) GATE PANELS SPAN
450' GATE LENGTH
EL. 684.5
STAINLESS STEEL MAIN ANCHOR
BOLT TYP 12' ON CENTER
January 2011
COLLAPSIBLE REINFORCED RUBBER
RESTRAINING STRAP TYP (3) PLACES
EACH 19.56' GATE SECTION
_j
INFLATABLE DUAL CHAMBER AIR BLADDER
SUPPLIED IN NOMINAL19.56' LENGTHS
RESTRAINING STRAP ANCHOR BOLT TYP
(6) PLACES EACH 19.56' GATE SECTION
PageS
Copper Valley Electric Association, Inc. -Allison Lake Hydroelectric Project
Addendum -Final Feasibility Report
2. Power Studies
2.1 Unconstrained Run-of-River Operation
By definition, without a reservoir to regulate available flows at the intake, a hydropower project can
only be operated when instantaneous flows are within the range of physical capability of the
generating equipment. All flows greater than the maximum hydraulic capacity of the equipment
will flow past the intake as spill. In addition, all flows required for other instream uses as well as all
flows less than that required to operate the smallest hydropower unit at the site must be passed by
the intake.
This condition is illustrated in Figure 2.1 in the form of an annual flow duration curve for the run-of-
river hydropower arrangement described in Section 1. The curve, which is based on the hydrology
defined in the FFS, shows that a run-of-river facility installed on Allison Creek could operate
whenever the flows in the creek are between 85 ds and 9 cfs for the condition:
• The maximum turbine flow is 80 ds;
• The. minimum instream flow release is 5 cfs; and
• The minimum turbine flow is 4 ds.
Figure 2.1
Allison Creek Flow Annual Flow-Duration Curve
200.0~---,----,----,----~---,-----,----,----,----,----.
-spilr -----
~ ~ 100.0 t----+-• .. -+----t-
--Generation 23.3 GWh --
(Unit Qm = 80 cfs)
0 u:::
Qmin=5 cfs
Excedence
80% 90% 100%
nit Qmin = 4 cfs
On this basis, the plant could operate approximately 62% of the time and the total amount of water
available for generation, Q8en, is represented by the blue cross-hatched area within Figure 2.1. The
difference in elevation between the diversion structure and the powerhouse times Q8en times 8,760
hours in a year provides an estimated 23.3 GWh as the average total amount of energy potentially
available from a run-of-river project on Allison Creek.
January 2011 Page 6
Copper Valley Electric Association, Inc. -Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
The same basic approach as applied to monthly flow duration curves results in the monthly
distribution of the 23.3 GWh as shown in Figure 2.2.
Figure 2.2
Allison Average Monthly Distribution of Energy Production
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
.....
~ -"T•V .c: <~
F= 1;3
~ -I 3.6. ------";._ Total Annual Energy --=
= 23.3 GWh -----~7 ------~~ 1-::--. ---·
~ ~------·,
F i-<"':'" --1-::-.• --
'---1-r-
----------i---r-r=--Ln-----
F
-'---r-r-r-...... p.l 0.0 0.0 0.1 lfi --... --""" Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
The above analysis is valid for the case that the energy from the Project is not constrained by system
load conditions. Specifically, the monthly distribution of energy as shown in Figure 2.2 is important
from the perspective of the ability of CVEA to assimilate energy from a run-of-river project on Allison
Creek into their system. For example, the Solomon Gulch Project can substantially accommodate
the total system under current load conditions for the month of july. Accordingly, the 4.8 GWh
available generation from Allison Lake could theoretically be stranded and the Allison Creek flows
would spill past the intake.
However, the complete loss of the 4.8 GWh will be offset to some degree by the storage capability
within Solomon Gulch by allowing Solomon Gulch to remain full longer into the fall season. The
analysis of this opportunity is with the AUTO Vista model as presented in the FFS is presented below
for Alt 4a and Alt 4b.
2.2 System Loads and Resources
2.2. 1 System Loads
The AUTO Vista model operates on hourly intervals to meet system loads in the most cost effective
manner using available system resources as a function of their respective cost of production. For the
present study, two cases for the system load were considered as follows:
• The system load as recorded by CVEA data for 2006, as was the basis for all previous
studies; and
• The above case with the addition of a new 2 MW load to continuously serve Petro Star
for 50 weeks of the year.
2.2.2 System Resources
The system resources considered for the existing case included the combined diesel plant facilities in
Valdez and Glennallen, the combined cycle unit as operated under the contract with Petro Star, and
the existing hydropower facilities at the Solomon Gulch Project. The proposed development
january 2011 Page7
~HATCH .. Copper Valley Electric Association, Inc . -Allison Lake Hydroelectric Project
Addendum -Final Feasibility Report
included the additions as discussed in Section 1 as well as retirement of the existing thermal
generation resources to the extent possible in each respective case under consideration.
2.3 AUTO Vista Model: Allison Creek Run-of-River Hydropower Development
AUTO Vista was used to evaluate the generation benefits of various upgrade configurations under
consideration for the Project during the studies leading to the FFS Report. As stated at the close of
Section 1, the focus of this Addendum includes Alt 4a and Alt 4b as discussed below. The following
is a description of the program and a discussion of the how AUTO Vista was applied for the
condition that the run-of-river operation of the Project is required to operate within the CVEA system.
The AUTO Vista model for the Project includes the drainage basins for both the existing Solomon
Gulch Project and Allison Lake. It is comprised of a series of arcs and nodes with each element
having its set of characteristics as defined in the FFS. The graphical model for the existing system, Alt
4a and Alt 4b as expressed in these terms is shown in Figure 2.3. Major features of the AUTO Vista
model are briefly described below.
Figure 2.3
AUTO Vista Model Elements: Alt 4a and Alt 4b
SLGQ
,._._,~
SLGP
(Solomon Gulch Power)
2.4 Hydrology
(Solomon Gulch Spill)
SLGINS_RJ
S_SINK
(Solomon Gulch INS June)
(Source_Sink)
ALSP
(Allison Lake
Power)
ALSQ
(Allison Lake
Inflow)
ALSSPWY_RJ
(Allison SPWY lWL)
ALST
(Allison Lake lWL)
A_SINK
(Source_Sink)
The hydrology used for the AUTO Vista model is based on the work done by the U.S. Army Corps of
Engineers (COE) in 1982 as part of their eva I uation of the potential project configurations for
maximizing the Allison Lake resource. The correlations developed from that study results in a 39-
year period of average daily flows from 1950 through 1989. A statistical analysis of this period of
record was performed to establish a representative smaller group of 7 years for use within the present
AUTO Vista. The set of 7 years was chosen on the basis of balancing the wet to dry conditions of
annual inflow to the two basins. The specific years chosen and the associated representative inflow
conditions are summarized in Table 2.1.
january 2011 PageB
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum -Final Feasibility Report
Table 2.1
AUTO Vista Hydrologic Years
Year
1969
1984
1954
1961
1957
1977
1989
Average
Percentile
10%
25%
25%
50%
75%
75%
90%
Total Inflow
Acre-Feet
28,900
30,800
30 900
33,200
36 100
37,900
42,800
34,400
2.5 Hydro Equipment Characteristics
The performance curves for the Solomon Gulch powerhouse have been included as provided by the
CVEA. The performance of new units at the proposed Allison Lake powerhouse for Alt 4a is based
on Hatch Acres in-house generic data for Pelton units. Both alternatives include a 6.5 MW
generating station comprised of two 3.25 MW generating units. A plot of the characteristics used in
this analysis for each of the 3.25 MW units is shown in Figure 2.4.
All elements of the conduit system components for each alternative have been assumed to perform in
accordance with published engineering data.
Figure 2.4
Allison Powerhouse Unit Characteristics - 2 x 3.25 MW Units
100% 5.0
90% 4.5
80% 4.0
70% 3.5
3.0 ~
! ! --Calculated Efficiency
60%
~ _.,_Caculated Power
2.5 t :t
0
2.0 Q.
ii 50%
·c
!f 40% ...
30% 1.5
20% 1.0
10% 0.5
0% 0.0
10 15 20 25 30 35 40 45
Discharge (cfs)
2.6 AUTO Vista Results
Stacked bar charts indicating the most efficient dispatch of system resources as required to meet the
system load are included in Appendix A for the existing condition, Alt 4a, and Alt 4b. The first
charts compare the existing condition to the development alternatives for the 1961 water year, which
is the 50% year as indicated in Table 2.1.
january 2011 Page 9
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
The annual generation for the base case of the existing load and resource condition for each of the 7
years included in the analysis is shown in Table 2.2 and the annual generation for Alt 4a and Alt 4b
for the existing load condition is shown in Tables 2.3 and 2.4 below.
Table 2.2
Annual Generation -Existing Condition, Loads and Resources
Generation (MWh)
Year Solomon Allison Total Hydro Diesel Cog en Total
1969 51,900 0 51,900 11 ,300 23,100 86,400
1984 55,200 0 55,200 8,100 23,000 86,400
1954 55,700 0 55,700 7,600 23,000 86,400
1961 59,700 0 59,700 6,100 20,600 86,400
1957 58,500 0 58,500 7,200 20,700 86,400
1977 61,800 0 61,800 3,100 21,500 86,400
1989 62,100 0 62,100 4,400 19,900 86,400
Average 57,800 0 57,800 6,800 21,700 86,400
Table 2.3
Annual Generation -Alt 4a w/ Existing Load
Generation (MWh)
Year Solomon Allison Total Hydro Diesel Cog en Total
1969 54,600 13,700 68,400 500 17,500 86,400
1984 54,000 15,100 69,200 300 16,900 86,400
1954 49,500 13,800 63,400 500 22,500 86,400
1961 53,200 14,100 67,300 500 18,500 86,400
1957 55,100 11 ,800 67,000 500 18,900 86,400
1977 57,800 12,400 70,200 300 15,900 86,400
1989 57,900 10,300 68,200 400 17,800 86,400
Average 54,600 13,000 67,700 400 18,300 86,400
Table 2.4
Annual Generation -Alt 4b w/ Existing Load
Generation (MWh)
Year Solomon Allison Total Hydro Diesel Cogen Total
1969 55,100 15,300 70,400 500 15,500 86,400
1984 55,000 16,200 71,200 400 14,800 86,400
1954 51 ,900 13,600 65,500 500 20,300 86,400
1961 55,300 14,400 69,800 400 16,200 86,400
1957 56,100 12,900 69,000 500 16,800 86,400
1977 59,300 12,900 72,200 500 13,700 86,400
1989 59,300 10,900 70,100 500 15,800 86,400
Average 56,000 13,700 69,700 500 16,200 86,400
january 2011 Page 10
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
The annual generation for the base case of the additional 2MW load and resource condition for each
of the 7 years included in the analysis is shown in Table 2.5 and the annual generation for Alt 4a and
Alt 4b for the additional 2MW load condition is shown in Tables 2.6 and 2.7 below.
Table 2.5
Annual Generation-Existing Resources w/ 2 MW Additional Load
Generation (MWh)
Year Solomon Allison Total Hydro Diesel Cog en Total
1969 51,700 0 51,700 28,700 23,100 103,500
1984 54,800 0 54,800 25,600 23,100 103,500
1954 55,500 0 55,500 24,900 23,100 103,500
1961 59,100 0 59,100 21,400 23,000 103,500
1957 62,100 0 62,100 19,800 21,700 103,500
1977 66,000 0 66,000 15,200 22,400 103,500
1989 66,500 0 66,500 15,500 21,600 103,500
Average 59,400 0 59,400 21,600 22,600 103,500
Table 2.6
Annual Generation -Alt 4a w/ 2 MW Additional Load
Generation (MWh)
Year Solomon Allison Total Hydro Diesel C~en Total
1969 57,000 18,100 75,100 3,000 25,500 103,500
1984 57,700 19,000 76,700 3,000 23,900 103,500
1954 53,500 17,800 71,300 8,200 24,100 103,500
1961 58,900 16,600 75,500 4,200 23,800 103,500
1957 59,600 15,200 74,800 4,600 24,200 103,500
1977 61,900 15,700 77,700 2,000 23,900 103,500
1989 62,600 14,000 76,600 4,600 22,400 103,500
Average 58,700 16,600 75,400 4,200 24,000 103,500
Table 2.7
Annual Generation -Alt 4b w/ 2 MW Additional Load
Generation (MWh)
Year Solomon Allison Total Hydro Diesel Cog en Total
1969 58,200 19,000 77,200 900 25,400 103,500
1984 58,500 20,200 78,700 1,000 23,900 103,500
1954 55,600 17,800 73,400 5,900 24,200 103,500
1961 60,400 17,100 77,500 2,300 23,700 103,500
1957 61 ,300 15,600 76,900 2,600 24,100 103,500
1977 63,800 15,700 79,500 300 23,700 103,500
1989 63,800 14,900 78,600 2,500 22,400 103,500
Average 60,200 17,200 77,400 2,200 23,900 103,500
The annual general benefits from the AUTO Vista Analyses for Alt 4a and Alt 4b can then be
summarized for each load case as shown in Table 2.8 in terms of the incremental hydropower
generation and associated reduction on thermal power as required to satisfy the system load for each
of the alternatives under consideration. Please note that the minor differences between the hydro
and thermal generation values for each alternative are due to rounding within the AUTO Vista
modeling.
january 2011 Page 11
~HATCH~
Table 2.8
Annual Benefits -Alt 4a & 4b
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
Existing Load-Generation (MWh) 2 MW Addition-Generation (MWh)
Resource Existing Alt 4a Alt4b Existing Alt 4a Alt 4b
Hydro 57,800 67,700 69,700 59,400 75,400 77,400
Fossil 28,500 18,700 16,700 44,200 28,200 26,100
Total 86,300 86,400 86,400 103,600 103,600 103,500
Benefit 9,900 11,900 16,000 18,000
january 2011 Page 12
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
3. Project Construction Cost and Construction Schedule
Construction costs and schedules were prepared and reported for the various upgrade configurations
under consideration for the Project during the Pre-Feasibility Study, Interim Feasibility Review, and
Final Feasibility Study. As stated at the close of Section 1, the focus of this Addendum to the Final
Feasibility Study Report is Alt 4a and Alt 4b as discussed below.
3.1 Construction Cost Estimates
All cost estimates are based on January 2010 bid price levels. The Direct Construction Cost for each
alternative is the total of all costs directly chargeable to the construction of the project and in essence
represents a contractor's bid. Indirect costs include an allowance for contingencies, engineering, and
owner administration and are added to the Direct Construction Cost to result in the Total
Construction Cost. The contingency used for all alternatives is 25%. The assumed Engineering and
Owner Administration during the design and construction phase of the Project is 15% of
construction cost for all alternatives, inclusive of contingencies.
The period of time required to complete the Federal Energy Regulatory Commission (FERC) pre-filing
licensing process can be expected to be approximately 3 years, which started in September 2008
with the receipt of the Preliminary Permit from the FERC. At this time, it is planned that a license
application would be ready to be filed with the FERC in the Fall of 2011. It is anticipated that the
subsequent post-filing process would result in a license issued by the FERC within approximately 2
years following submittal, resulting in a FERC Order Issuing License in late 2013. The winter site
conditions and the development and review of final construction plans as required by the FERC
would lead to a July construction start in 2014. Adding another 2 + years to construct the project
indicates a realistic on-line date for the Project would be in the range of late 2015 to early 2016.
Accordingly, it is appropriate to include escalation to the above costs to determine a realistic on-line
cost for the Project. However, for the purposes of the present economic analyses, 2010 dollars are
used herein to avoid the need to hypothesize what the cost of thermal generation may be that far into
the future.
3. 1. 1 Alternative 4a
The basis for the construction cost of the various elements of Alt 4a are listed below as follows:
January 2011
• Mobilization. The mobilization cost is taken directly from the estimates for Alt 3c on
the basis that the construction activities for the initial year of construction are nearly
identical.
• Construction Access Trail. The cost of the 4,500 foot access trail to the high point of the
penstock above the powerhouse is estimated as 60% of the estimate for the access road
for Alt 3c. The overall length of the trail is approximately 30% of that of the route for
Alt 3c, and the width of the road bench for the trail will be two-thirds for that required
for Alt 3c. However, the alignment for the trail will be the same as that for the Alt 3c
road, which is by far the most difficult portion for construction.
• Diversion Structure. The cost for the diversion structure is based on the unit costs for
similar features of the nearby diversion structure for the Humpback Creek project that is
currently under construction for Cordova Electric Cooperative.
Page 13
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
• Surface Pipeline I Penstock. The cost of the surface pipeline I penstock is based on the
detailed estimates developed for the comparable penstock segments of Alt 3c as
included in Appendix E of the FFS.
• Powerhouse. The costs for the major equipment within the 6.5 MW powerhouse are
based on preliminary quotations from equipment suppliers while the cost for other
lower cost items were obtained from in-house cost data and from recently obtained bid
prices on similar construction.
• Switchyard. The switchyard cost is taken directly from the estimate for Alt 3c.
• Transmission. The transmission cost is taken directly from the estimate for Alt 3c.
The resulting construction cost estimate for Alt 4a is summarized in Table 3.1.
Table 3.1
Alternative 4a
Total Construction Cost (Bid 1/2010)
Item
1. Mobilization
2. Construction Access Trail
3. Dam, Intake & Spillway
a Diversion Structure
b. Spillway
4. Surface Penstock I Pipeline
a. HOPE Pipeline
b. Steel Pipeline
Subtotal
5. Powerhouse
a Civil Works
b. Turbine & Generator
c. Misc. Mech. Equip.
d. Misc. Elec. Equip.
e. Bridge Crane
Subtotal
6. Switchyard
7. Transm. & Interconnection
Direct Construction Cost (Bid 1/09)
Escalation
Direct Construction Cost (Bid 1/1 0)
Contingencies
Engineering & Owner Admin.
Total Construction Cost (Bid 1/10)
3.1.2 Alternative 4b
$2,230,000
$0
$0
$5,176,000
$2,594,000
$4,710,000
$683,000
$1,015,000
$187 000
$1,573,000
$2,916,000
$2,230,000
$5,176,000
$9,189,000
$525,000
$310.000
$21,919,000
-$590,000
$21,329,000
$6,076,000
$4.111.000
$32,106,000
The cost for the addition of a Obermeyer Gate 5 feet in height on the top of the Solomon Gulch
Spillway was considered on its own as an incremental feature for the CVEA system. The cost of this
addition is based on a preliminary quotation for the gate materials and a configuration as suggested
by the Obermeyer company. The costs for modifications to the existing spillway and installation of
january 2011 Page 14
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
the gate are based on estimated quantities of construction and in-house unit costs. The resulting cost
for Alt 4b is summarized in Table 3.2.
Table 3.2
Alternative 4b
Total Construction Cost (Bid 1/2010)
Labor
Equipment
Materials
Item
Direct Construction Cost (Bid 1/1 0)
Contingencies
Engineering & Owner Admin.
Total Construction Cost (Bid 1/10)
3.2 Construction Schedule
$2,106,000
$235,000
$1 .951.000
$4,292,000
$858,000
$773,000
$5,923,000
The construction schedule for Alt 4a and Alt 4b is primarily controlled by the following major
factors:
• Delivery time for major powerhouse equipment;
• Access to Allison Lake for construction activity;
• Four month window for construction activity at Allison Lake, generally from mid-july to mid-
October depending on conditions; and
• Earliest most reasonable construction start in 2014 based on estimated timing of FERC
license issuance (as discussed above).
A similar approach has been used to develop a schedule for each alterative relative to the purposes
of the cost estimates presented above and the annual costs presented below for each alternative. The
schedule for Alt 4a is presented in Figure 3.3 as an example thereof.
january 2011 Page 15
Figure 3.3
Alternative 4a
Construction Schedule
1st Season· 2014
Month 1 Month 2 Month 3
I I I
Blaze trail to diversion structure
and foundation prep
Month 4
Access ro ad to 45 +00
I 00' I day-single shift {V'
Access to oowerhouse
I I "' Lavdown areas · powerhouse
I I I
Powerhouse foundation pre
I
Warehouses I offices
I
Housing: Man·Camp In Valdez
G) Activity Duration (weeks)
3.3 Economic Analysis
Copper Valley Electric Association, Inc.-Allison lake Hydroelectric Project
Addendum-Final Feasibility Report
2nd Season -2015 3rd Season -2016
Month 1 Month 2 Month 3 Month 4 Month 1 Month 2 Month 3 Month 4
I
Divers ion structure
Penstock to 2 5 + 00 /
~'·'-·®-~
PenstDP.o 55 ·00 to~ /
Penstock PJ to 5~00 / ( (9)
I / Powerhouse
Switchyt d / !
I I • • 1 Line
I_
Housi ng: Man-Camp In Valdez
I I
Annual costs of the Project can be apportioned into fixed and variable costs. The fixed amount
includes amortization of the Total Capital Requirements less earnings on Reserves and is based on
7% interest rate financing over a 30-year term. Variable annual costs escalate each year and include
operation and maintenance (O&M) costs, administrative and general expenses, interim replacements,
and insurance. The basic assumptions for determining the annual fixed and variable costs of the
Project are shown in Table 3.3.
Table 3.3
Basic Assumptions for Economic Analyses
Item Value
Construction Period (Ait 4a) 25 months
Financing Term 30 years
Financing Interest Rate 7%
Reinvestment Rate Same as fi nand ng
Escalat ion of Project Costs 3% annually
Financing Reserve 1 year of debt service
Financing Expenses 3% ofTotallnvestment Cost
Variable Annual Costs $500,000
january 2011 Page 16
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
3.3.1 Cost of Power-Alternative 4a
The Total Investment cost includes interest during construction (I DC) over an assumed 25-month
construction period. As outlined above, we have assumed that construction at the project site would
come to a stop during the winter months, with the exception of equipment installation within the
powerhouse structure. The development of the annual cost for Alt 4a is shown in 2010 dollars on
Table 3.4.
Table 3.4
Alternative 4a-First Year Annual Cost (2010 dollars)
Item
Total Construction Cost (Bid 1/10)
Interest During Construction
Total Investment Cost
Reserve Fund
Financing & Legal
Working Capital
Total Capital Requirements (1/10)
Annual Cost
Debt Service
O&M Cost
Administrative & General
Insurance
Interim Replacements
Earnings on Reserve Fund
Total First-Year Annual Cost
Cost
$32,106,000
2.435.000
$34,541,000
3,127,000
1,036,000
100.000
$38,804,000
$3,127,000
280,000
112,000
50,000
50,000
(219.000>
$3,400,000
As discussed in Section 2 above, the unit cost of power becomes a function of the extent to which
the power available from the Project can actually contribute to the CVEA system load on a day-to-
day, hour-to-hour basis. In this regard, three scenarios are presented including:
1. The AUTO Vista studies performed indicate that a total of 9,900,000 kWh from the
Project can be used within the existing CVEA system load.
2. With an additional 2 MW of load within the CVEA system, the AUTO Vista studies
performed also indicate that a total of 16,000,000 kWh from the Project can be
effectively utilized.
3. The review of the available flow data for Allison Creek indicates that a 6.5 MW run-of-
river project at the site would have the capability to produce a total of 23,300,000 kWh
at such time that the CVEA system load that would not constrain its operation.
The cost of power resulting from these three scenarios is presented in Table 3.5.
january 2011 Page 17
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
Table 3.5
Alternative 4a -Cost of Power
Item
Total First-Year Annual Cost
Alt 4a with Existing System Load (kWh)
First-Year Cost of Power (1/2010) ($/kWh)
Alt 4a with 2 MW Additional Load (kWh)
First-Year Cost of Power (1/2010) ($/kWh)
Alt 4a with Expanded CVEA System (kWh)
First-Year Cost of Power (1/2010) ($/kWh)
3.3.2 Cost of Power-Alternative 4b
Value
$3,400,000
9,900,000
$0.343
16,000,000
$0.213
23,300,000
$0.146
As indicated by the results included in Table 2.8, the addition of the Obermeyer gate to the Solomon
Gulch spillway adds 2,000,000 kWh to the energy for the Alt 4a development with and without the
anticipated additional 2 MW of load to the CVEA system. Further, the Alt 4b contribution to the
CYEA system load is essentially the same without a run-of-river development of Allison Creek. The
resulting cost of power during the first year of operation is shown in Table 3.6.
january 2011 Page 18
~HATCH ..
Table 3.6
Alternative 4b -Cost of Power
Item
Total Construction Cost (Bid 1/10)
Interest During Construction
Total Investment Cost
Reserve Fund
Financing & Legal
Working Capital
Total Capital Requirements (1/10)
Annual Cost
Debt Service
O&M Cost
Administrative & General
Insurance
Interim Replacements
Earnings on Reserve Fund
Total First-Year Annual Cost
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
Cost
$5,469,000
255.000
$5,724,000
526,000
172,000
100.000
$6,522,000
$526,000
280,000
112,000
50,000
50,000
(37.000>
$981,000
Added Hydro Generation, Existing System (kWh)
First-Year Cost of Power (1/2010) ($/kWh)
2,000,000
$0.491
january 2011 Page 19
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
4. Regulatory and Environmental Considerations
Section 5 of the FFS presents our full evaluation of the regulatory and environmental considerations
relative to hydroelectric project development in general, and specifically, to a 4.5 MW storage
project at Allison Lake. Regulatory and environmental work continues to proceed toward
preparation of an Application for License to the FERC. This section presents the impacts on the
ongoing regulatory process and environmental investigations of the additional identified alternatives,
Alt 4a and Alt 4b.
4.1 Alternative 4a
4. 1. 1 Regulatory Considerations
CVEA issued a Preliminary Application Document (PAD), including the Draft Application for License
and Preliminary Draft Environmental Assessment (PDEA) (Draft Application) for the Allison Lake
Project on April 13, 2010. The PAD, including the Draft Application for License, described a
proposed 4.5 MW storage project and was prepared under the regulation for Major Unconstructed
Project Less Than 5 MW pursuant to 18 CFR 4.61.
The run-of-river modification to the Project would have an installed capacity of 6.5 MW and
therefore would be greater than 5 MW and the Application for License would be prepared pursuant
to 18 CFR 4.41, Major Unconstructed Project Greater Than 5 MW. This change in the applicable
FERC regulation would not significantly affect either the environmental work to date or the PDEA.
However, the change does necessitate that the engineering information be modified and expanded
as required under 18 CFR 4.41.
The change from the 4.5 MW storage project to the proposed 6.5 MW run-of-river project will
require:
1. Revision of the PDEA to present the run-of-river project description and related operation as
it differs from the storage project description and operation.
2. Preparation of the revised engineering exhibits. The Draft Application as provided on April
13, 2010, included a single engineering exhibit (Exhibit A) for the proposed 4.5 MW storage
project containing the required engineering information pursuant to 18 CFR 4.61. The
change to the proposed 6.5 MW run-of-river project changes the applicable FERC regulation
to 18 CFR 4.41 and the engineering exhibits expand to four exhibits (Exhibits A through D),
each containing greater detail and additional information beyond the single engineering
exhibit previously prepared.
3. Preparation and issuance of Revised Scoping Document 1 (SD1). SD1 was issued on April
22, 2010, and scoping meetings were held on May 10 and 12, 2010. The process for
issuing a revised SD1 was discussed with FERC staff. CVEA will not be required to hold new
scoping meetings, nor conduct an additional site visit (initial site visit was in 2005). FERC
Staff recommended that CVEA:
a. Issue a revised SD1 along with a revised PAD; and
b. Following provision of the revised documents, schedule a teleconference with the
resource agencies and other interested participants to discuss the revised proposed
Project.
In light of the above, the level of effort going forward for document preparation for the 6.5 MW run-
of-river option would be greater than that required for the 4.5 MW storage option due to the
january 2011 Page 20
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
redundancies involved with following the 18 CFR 4.41 process. However, the downstream benefits
in the activities for development of the run-of-river project would be greatly increased as discussed
below, greatly overweighing the additional effort required for document preparation and the
licensing process itself.
4. 1.2 Environmental Field Investigations
In support of the preliminary permit, environmental field investigations began in 2008 for the
Project. The status of these field investigations and desk-top reviews as of May 2010 is summarized
in Section 5 of the FFS and the complete reports can be found in Appendix F to the FFS. The major
studies conducted are listed in Table 4.1.
All of the studies to date are equally applicable to the run-of-river project as discussed herein and
those arrangements considered in the FFS. Further, the selection of a run-of-river arrangement for the
project is not expected to require any new major areas of study to support the preparation of the
FERC License Application. However, as indicated by Table 4.1, on-going work will be required in
several areas as follows:
Table 4.1
• Water Use & Quality. The on-going work in this area will primarily be continued
monitoring of the two stream gages in order to develop and maintain a continuous record for
the flow regime for Allison Creek.
• Biological Resources. The baseline work for fish populations and habitat, vegetation, birds
and mammals, and wildlife habitats is complete. Areas that will require further work
include:
Aquatic Resources: Further work will be necessary to provide a basis for final
negotiation of the amount of flow required to maintain an in-stream flow between
the diversion structure and the powerhouse.
Wetlands: Further work will be required to evaluate the extent of any wetlands
located along the selected transmission line alignment.
• Archaeological I Historical Resources. The field work for the archaeological and historical
resources of the project area has been completed.
Summary of Major Environmental Field Studies
Type of Field Investigation Conducted By Timeline
Geological Resources
(As described in Section 2) R&M Consultants Began: 2008
Completed: 2009
Began: 2008
Completed: on-going Water Use and Quality R&M Consultants
Biological Resources
-Fish and Aquatic Resources
Began: 2008
Completed: on-going
-Vegetation
-Wetlands ABR, Inc.
-Birds and Mammals
-Wildlife Habitats
Began: 2009
Completed: 2010 Archaeological/Historical NLUR, Inc.
january 2011 Page 21
~HATCH~ Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
4. 1.3 Environmental Considerations
While the regulatory framework for Alt 4a is more detailed than that associated for Alt 3c, the
associated scope of environmental issues is greatly reduced. The more significant elements of this
comparison are:
1. Allison Lake would be left in its natural state in the case of Alt 4a, which has not been the
case for all arrangements previously considered. The lake would have been drawn down by
as much as 100 feet during the winter season in the lake-tap alternatives. Conversely, the
lake would have been raised 43 feet in the case of Alt 3c thereby inundating the existing
east and west shorelines and the delta at the south end of the lake.
2. The construction activity of the dam near the outlet of the lake would disturb a significant
area with attendant concerns for water quality within Allison Creek to a much greater extent
than would be associated with the construction of the diversion structure for Alt 4a.
3. The construction of the diversion structure for Alt 4a would not require that a road be
constructed to the outlet of Allison Lake nor the extensive amount of traffic associated with
the construction of the major dam structure included with Alt 3c.
4. In the case of Alt 3c, there would be a potential for seepage beneath and around the dam
resulting in a loss of water available for hydropower generation as well as changed ground
water conditions in the glacial moraine downstream of Allison Lake. While not likely, any
seepage that may occur at the location of the diversion structure associated with Alt 4a
would be very minor.
5. In the case of Alt 4a, the flow regime within Allison Creek would remain unchanged
between Allison Lake and the diversion structure as well as within the reach downstream of
the powerhouse, the latter being the area of primary concern for the habitat for both resident
and anadromous fish species.
All of these factors would greatly reduce the level of effort required for Alt 4a as compared to Alt 3c
for agency consultation throughout the remaining licensing activities as well as for environmental
monitoring during construction and operation of the project.
4.2 Alternative 4b
4.2. 1 Regulatory Considerations
An amendment to the existing Solomon Gulch Project FERC License (No. P-2742) would be required
for the proposed five foot raise in the normal maximum water surface of Solomon Lake as proposed
for Alt 4b. The amendment would require that agency consultation take place in a manner
comparable to that currently anticipated for the Allison Lake development. As part of the
consultation process, issues that were not resolved according to current practice during the original
licensing process would likely be revisited by existing agency staff.
4.2.2 Environmental Field Studies
Ostensibly, the environmental field studies would focus on habitat values within the additional area
to be submerged surrounding Solomon Lake as the result of the proposed five foot raise in the
normal maximum water surface of Solomon Lake. It can be expected, however, that agency
consultation would result in requests for further studies with regard to other aspects of the project
that were not studied in accordance with current practice as part of the original licensing process.
january 2011 Page 22
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
4.2.3 Environmental Considerations
No specific concerns of a fatal flaw nature have been identified with regard to the environmental
effects of the proposed five foot raise in the normal maximum water surface of Solomon Lake as
proposed for Alt 4b.
january 2011 Page 23
~HATCH~ Copper Valley Electric Association, Inc.-Allison lake Hydroelectric Project
Addendum-Final Feasibility Report
5. Conclusions and Recommendations
5.1 Conclusions
5. 1. 1 Alternative 4a
In addition to the general conclusions relating to the development of a hydropower project in the
Allison Creek basin as provided in the FFS, conclusions specific to the run-of-river Alt 4a gained as
the result of the present evaluation include the following:
• The scope of the project as proposed for the run-of-river Alt 4a is significantly reduced from
that associated with Alt 3c.
• A run-of-river Alt 4a development of the Allison Creek basin can produce 23.3 GWh of
energy on an average annual basis within the environment of an unconstrained system load.
• A run-of-river Alt 4a development of the Allison Creek basin would produce 9.8 GWh of
energy on an average annual basis within the existing CVEA system load. The project is not
cost effective under this load condition.
• With the addition of 2 MW to the CVEA system load, the Alt 4a average annual contribution
to the CVEA system load would increase to 16.0 GWh. On this basis, the project would be
competitive with the cost of diesel generation.
• Further increases in the CVEA system load would in turn result in a further reduction in the
cost of power from Alt 4a.
• The reduced scale of the hydropower development of the Allison Creek basin as offered by
Alt 4a would in turn minimize the risk of construction cost overruns relative to that
potentially associated with Alt 3c.
• The diversion structure proposed for Alt 4a would entail a minimal, if any, risk of seepage or
other dam safety related issues in contrast to that potentially associated with the large dam at
the outlet of Allison Lake as proposed for Alt 3c.
• On the basis that the installed capacity of the run-of-river Alt 4a is expected to be greater
than 5 MW, FERC 18 CFR 4.41 would be the required regulation for the preparation of a
FERC License Application for the project.
• The reduced scale of the hydropower development of the Allison Creek basin as offered by
Alt 4a will result in an overall reduction in environmental effects relative to that associated
with Alt 3c.
• In contrast to any of the storage project arrangements as previously considered for
development of the Allison Creek basin, the run-of-river configuration as proposed for Alt 4a
would maintain the existing flow and temperature regimes downstream of powerhouse. This
would be a major advantage for Alt 4a owing to the critical importance of this reach of
Allison Creek to resident and anadromous fish populations.
• Alt 4a is superior to Alt 3c in all respects.
5. 1.2 Alternative 4b
Conclusions specific to Alt 4b gained as the result of the present evaluation include the following:
january 2011
• The addition of inflatable gates to the Solomon Gulch Spillway as proposed for Alt 4b would
add approximately 2 GWh of average annual energy to the CVEA system for service to all
system load and resource conditions considered for the project, existing and future.
Page 24
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
• The addition of inflatable gates to the Solomon Gulch Spillway as proposed for Alt 4b would
require an amendment to the existing FERC License for the Solomon Gulch Project.
• On the basis of the energy potential and cost estimates prepared for this evaluation, the
addition of inflatable gates to the Solomon Gulch Spillway as proposed for Alt 4b would not
currently be economically viable relative to the other resources available to the CVEA.
5.2 Recommendations
Based on the conclusions referenced and outlined above, we provide the following
recommendations:
• Adopt Alt 4a as the preferred alternative for the development of the hydroelectric potential
of the Allison Creek basin;
• Terminate further consideration of Alt 3c and Alt 4b;
• Complete the analysis of the environmental effects of a hydropower development within the
Allison Creek basin on the basis of Alt 4a;
• Optimize the capacity of the powerhouse for the run-of-river Alt 4a; and
• Prepare a FERC License Application for Alt 4a pursuant to the provisions of 18 CFR 4.41.
January 2011 Page 25
~HATCH~
6. References
Copper Valley Electric Association, Inc.-Allison Lake Hydroelectric Project
Addendum-Final Feasibility Report
1. Hatch Acres Corporation, Allison Lake Hydropower Development-FINAL FEASIBILITY STUDY,
prepared for Copper Valley Electric Association, May 2010.
2. HDR Engineering, Inc., SOLOMON GULCH HYDROELECTRIC PROJECT-RESERVOIR
CAPACITY-FEASIBILITY STUDY, prepared for Copper Valley Electric Association, November
1991.
january 2011 Page 26
Appendix A
Aft 4a System Dispatch
~HATCH~
-.. s
~ ._.
c
0
+J ro s.....
Q)
c
Q)
C)
SG 1
Existing
Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Alt4a
-I I
SG 2 Allison 1 Allison 2 Diesel Cogen
AUTO Vista ANALYSIS-AL T 4a
Annual Dispatch w/ Existing Load -1961
•
Oct Nov
Appendix A -1
~HATCH ..
-..
$
~ ._.
c
0
+-' ~
Q) c
Q)
(.9
SG 1
Existing + 2 MW
Nov Dec Jan Feb Mar · Apr May Jun Jul Aug Sep
Alt4a
[ I
SG 2 Allison 1 Allison 2 Diesel Cogen
AUTO Vista ANAL YS/S-AL T 4a
Annual Dispatch w/ 2 MW Added Load Load -1961
..
Oct Nov
Appendix A -2
~HATCH-
•
AppendixB
Obermeyer Gate -
Cost Estimate
~HATCH™
SOLOMON GULCH HYDROELECTRIC FACILITY OBERMEYER GATE INSTALLATION
Construction Cost Summary
NEW INSTALLATION
Based on Dick Freeman's A vista-Nine Mile estimate dated Dec 18, 2007 and Jim Rutherford's Humpback Creek Estimate, 03/2009, and Obermeyer quote dated October 22, 2010
TOTAL LABOR EQUIPMENT
Crew Hours/
No. Item Size Crew Hours Rate Total Item Qty Rate Weeks
1 Mobilization $57,200 $42,000
7 80 560 75 $42,000 966 Loader 1 4000 2
Flatbed trucks 2 1500 2
Pettibone Fork Lift 1 600 2
2 Remove Existing Splitter Piers $67,800 $51,500
7 100 700 75 $52,500 600 elm compressor 1 1800 2
Pettibone Fork Lift 1 600 2
3 Drill and Set Anchors • 112 each $210,320 $144,000
8 240 1920 75 $144,000
0 600 ctm compressor 1 1800 4
airtracks 2 2700 4
Pettibone Fork Lift 1 600 4
4 Pour Concrete $311,366 $180,000
Description: Pour additional spillway concete to
anchor Obermeyer Gate, middle spiller wall and
create a right abutment. Appnox. 524 CY of
concrete with a 1 :2:4 mix, 4 x 60 hour weeks
Labor -1 0 men working 6 1 0 hour days 10 240 2400 75 $180,000
Generator -60 kw 1 900 4
Compressor -66 ctm 1 2100 4
Mix truck 1 5500 4
Water truck 1 2500 4
Concrete pump 10 600 4
Pettibone Fork Lift 1 600 4
Mise vibrators, saws, drill! 1 0 4
5 Install Air Piping Along Crest $78,540 $60,000
8 100 800 75 $60,000 600 cfm compressor 1 800 2
flatbed truck 1 1500 2
Pettibone Fork Lift 1 600 2
12 03 2010 Obermeyer Annual Cost_arg_joee.xls
•
MATERIALS
Total Item Qty Rate Total
$15,200 $0
$8,000 1 $0
$6,000
' $1,200
I
$4.800 $10.500
$3,600 Miscellaneous 20% of labor 10500 1 $10,500'
$1,200
$0
$31,200 $35,120
$0 Miscellaneous 5000 1 $5,000
$0 Anchors 1" x 15ft x 56 ea x 2.67 lbs ea. 5000 3 $15,000
$7,200 Grout 1680 9 $15,120
$21,600
$2,400
$70,4QO $80,96CI
$0
$3,600 Miscellaneous 5000 1 $5,000
$8,400 Form lumber 27600 $0 .50 $13,800
$22,000 Rebar-cut, bundled in town 32390 $0.80 $25,912
$10,000 Cement 72 $90 $6,480
$24,000 Sand 171 $10 $1,710
$2,400 Gravel 281 $12 $3,372
$0 Additives/Curing add 10% to all 1.38 $3,400 $4,692
$5,8® $12,7<40
$1,600
$3,000
$1,200
2" pipe with fittings, galvanized 530 20 $10,600
miscellaneous 2140 1 $2,140
SOLOMON GULCH HYDROELECTRIC FACILITY OBERMEYER GATE INSTALLATION
Construction Cost Summary
NEW INSTALLATION
Based on Dick Freeman's Avista-Nine Mile estimate dated Dec 18, 2007 and Jim Rutherfoofs Humpback Creek Estimate, 03/2009, and Obenneyer quote dated October 22, 2010
No.
6
7
6
9
Item
Set Obenneyer Assemblies In Place
Install Abubnent Seal Plates (both ends)
Install CompreHOr, MCC, Locel Controls
Raise Reservoir, Startup, Turnover
SUBTOTAL
Supervision (% oflabor)
Ovemead (% of labor)
Overtime factor(% of total labor)
Profit on labor(% of labor)
Profit on materials (%of labor)
Contigency (20%)
Engineering & Owqner Administration ( 15%)
SUBTOTAL
12 03 2010 Obermeyer Annual Cost_arg_Joee.xls
TOTAL LABOR
Crew Houl'$/
Size Crew Hours Rate
$1,764,325
13 240 3120 75
$479,400
15 360 5400 75
$78,000
8 100 800 75
$34,000
4 100 400 75
$3,080,951 80 1560 16100
$301,875
$181,125
$169,050
$148,764
$81,903
$792,734
ll1M§Q
$5,469,861
25%
15%
10%
8%
5%
Total
$2U,OOO
$234,000
$405,000
$405,000
$80,000
$60,000
$30,000
$30,000
$1,207,500
$301,875
$181,125
$169,050
$148,764
Item
Pettibone Fork Lift
60 ton crane
600 cfm compressor
flatbed truck
Pettibone Fork Lift
600 cfm compressor
mish air tools
flatbed truck
flatbed truck
10Ton Crane
Miscellaneous
Pettibone Fork Lift
Miscellaneous
EQUIPMENT
Qty Rate Weeks
1 600 4
1 7000 4
1 1800 4
1 1500 4
1 600 6
1 1800 6
13500 1 2
1 1500 6
1 1500 2
1 7000 1
1 1000 2
1 600 2
2000 1 1
•
MATERIALS
Total Item Qty Rate Total
$43,600 $1 ,486,725
$0
$2,400 Obermeyer $1 ,486,725'
$28,000 2 each 225' long x 5' high, assumed
$7,200 same cost as A VISTA, 9 mile
$6,000 250' forlQ_ X 1 0' high)
$50,400 $24,000:
$0
$3,600 Drill bits, e~o~ grout 14000 1 $14,000
$10,800 Anchors 600 1 $600
$27,000 Concrete 1200 1 $1 ,200
$9,000 Form lumber 500 2 $1,000
Handrail platforms lbs 1440 5 $7,200
$12,000 $6,000
$3,000 Miscellaneous 6000 1 $6,000
$7,000
$2,000
$2,000 $2,0001
$2,000 Miscellaneous --------------2000 -1 -$2,000j
$235,400 $1,638,051
$81 ,903
OBERMEYER HYDRO, INC.
P.O. BOX 668FT. COLLINS, COLORADO 80522 USA TEL 970-568-9844 FAX 970-568-9845
E-mail: hydro@obermeyerhydro.com WWW: htto://www.obermeyerhydro.com
October 22, 2010
Project Quotation Sheet
Project: Solomon Gulch, Alaska
Client: Joe Earsley, Hatch Associates Consultants, Inc.
Gate Size: 5' high x 450' long
Obermeyer Hydro, Inc. (OHI) is pleased to issue this proposal for the supply of an
Obermeyer Water Control Gate for the Solomon Gulch Project in Alaska. Obermeyer
Hydro will supply the following components for this project:
Steel Package: (23), nominal19.56' wide steel gate panel (4200-lbs each)
along with ductile iron clamp castings, hinge retainers, web
retainers, splitters, restraining strap clamps, and two UHMW
polyethylene plates. Gate panels and peripheral parts to be
sand blasted and coated with CeramKote 54 epoxy paint.
Ductile iron castings shall be sand blasted and hot dip
galvanized in accordance with ASTM A 123 and ASTM 153.
Bladder Package: (23), nominal 19.56' wide two ply polyester reinforced dual
chamber air bladders complete with air bladder connection
assemblies for connection into owner supplied air piping.
Control System: One OHI model10-3 automatic water level control system.
Control system to utilize a Square D Momentum Series PLC
to maintain a user input upstream water elevation. PLC to
measure upstream water elevation using included KPSI
submersible depth transmitter. Control system provided in
dual Nema 12 rated electrical boxes (PLC and mechanical).
Operator interface to PLC to be via color touchscreen panel.
Control system to have capability to control up to three
independent gate zones.
Air Supply: Dual Ingersoll Rand model UP6-30-125 rotary screw air
compressors with desiccant air dryers, filtration system, and
400-gallon receiver tank. Each compressor to output 125-cfm
at 125-psig and shall actuate the gate to normal operating
pressure in approximately 60-minutes with both machines
operating. 3-phase power required.
Misc. Package: All stainless steel gate system anchor bolts, stainless steel
fasteners, stainless steel abutment and restraining strap
anchor bolts, interpanel seals, three copies of engineering
drawings and calculations, and three copies of operation and
maintenance manuals.
Obermeyer Hydro is pleased to offer this complete package FOB Wellington,
Colorado for the sum total of USD 1 ,486,725.00. This price is valid until November 30,
2010. Shop drawings will be available within 4-weeks of purchase order. Delivery of
gate shall be in accordance with mutually agreed upon project schedule
The above prices specifically exclude the following items:
1. Interconnecting wiring or piping.
2. Building for housing compressor and controls.
3. Installation except for any purchased supervision and training.
4. Any needed anchor bolt epoxy.
5. Bid, supply, or performance bond.
6. Federal, state, or any local taxes.
In addition to the above equipment supply package OHI also recommends the
following installation supervision and owner training program:
Trip One: Ten day on-site installation consulting trip by OHI technical during
gate installation. Purpose of the trip is to supervise the installation of
the gate and the control building equipment.
Trip Three: Two day system start-up and owner training trip. Day one will be
dedicated to gate testing and day two will be for owner training and
Operation and Maintenance manual review.
The price for the listed installation supervision and owner training program is USD
12,000.00. Additional on-site services are available for USD 1000.00 per day plus any
added travel related expenses.
As all parts are custom manufactured, a thirty percent (30%) deposit will be
required with the placement of an order. The balance, less five percent (10%) retention
shall be upon shipping from Wellington, Colorado. The retention shall be due net sixty
days after shipping from Wellington, Colorado or upon commissioning of gate whichever
comes first. OHI reserves the right to invoice for partial shipments.
All parts manufactured by Obermeyer Hydro are offered and guaranteed as
outlined in standard OHI sales agreement. Items that are supplied, but not manufactured
by Obermeyer Hydro, are covered by the original manufacturer's warranty.
Sincerely,
Obermeyer Hydro, Inc.
Robert Eckman
Vice President
2
SOLOMON GULCH, ALASKA
OHI BILL OF MATERIALS
SIZE: 5' x 450'
OCTOBER 22, 2010
COMPONENT DESCRIPTION QUANTITY EST WEIGHT/UNIT TOTAL WEIGHT
(POUNDS)
GATE SYSTEM
GATE PANEL (19.56' SECTION) 23 4200 96600
HINGE RETAINER A 450 4 1800
WEB RETAINER A 46 12 552
WEB RETAINER B 46 12 552
RESTRAINING STRAP CLAMP 138 20 2760
SPLITTER 23 7 161
CLAMP CASTINGS 225 134 30150
STAINLESS STEEL ABUTMENT PLATE 2 1500 3000
1/2"-13UNC x 1-1/4" STAINLESS STEEL HEX BOLT (SPLITTER BAR) 50 0.2 10
1/2"-13UNC STAINLESS STEEL FLAT WASHER (SPLITTER BAR) 50 0.2 10
3/4"-10UNC SS HEX NUT (HINGE FLAP) 1800 0.2 360
3/4" SS FLAT WASHER (HINGE FLAP) 1800 0.2 360
5/8"-11 UNC SS HEX NUT (SEALS) 560 0.2 112
5/8" SS FLAT WASHER (SEALS) 560 0.2 112
1"-8UNC x 4" STAINLESS STEEL HEX HEAD CAP SCREW (RESTRAINING STRAP) 70 2 140
1"-8UNC SS HEX NUT (RESTRAINING STRAP) 140 0.5 70
1" SS FLAT WASHER (RESTRAINING STRAP) 210 0.25 52.5
1" x 12" 304 STAINLESS STEEL ANCHOR BOLTS (REST. STRAP) 70 15 1050
1-3/4" x 24" STAINLESS STEEL ANCHOR BOLT (MAIN ANCHOR) 450 19 8550
1-3/4" STAINLESS STEEL SPERHICAL HEX NUT (MAIN ANCHOR) 450 3 1350
1-3/4" STAINLESS STEEL SPHERICAL WASHER 450 3 1350
AIR BLADDER (19.56' DUAL CHAMBER) 23 710 16330
HINGE FLAP (19.56' SECTION) 23 90 2070
RESTRAINING STRAP 70 25 1750
ABUTMENT SEAL 2 25 50
INTERPANEL SEAL 22 25 550
INTERBLADDER SEAL 25 1 25
OHI10-3 MECHANICAL CABINET (1-zone control system) 1 300 300
OHI10-3 SQUARED WATER LEVEL CONTROLLER 1 300 300
KPSI WATER LEVEL TRANSDUCER WITH 50' CABLE 1 25 25
OHI TSM-005 GATE POSITION SENSOR WITH 50' CABLE 2 25 50
INGERSALL RAND UP6-30-125 ROTARY SCREW AIR COMPRESSOR 2 1292 2584
INGERSALL RAND D2211M AIR DRYER 2 198 396
INGERSALL RAND GP216 AIR FILTER 4 25 100
INGERSALL RAND HE216 AIR FILTER 4 25 100
400-GALLON RECEIVER TANK 1 500 500
AIR CONNECTION ASSEMBLY 23 1 23
GATE SYSTEM TOTAL 174254.5
END
~HATCH,.