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ATTACHMENT 4
Black and Veatch Report (2011)

 This Page Intentionally Left Blank

WEST DIVIDE PROJECT
FEASIBILITY ASSESSMENT

PREPARED BY: BLACK & VEATCH

BLACK & VEATCH CORPORATION

JUNE 3, 2011

 Table of Contents
1. EXECUTIVE SUMMARY................................................................................................... 3
1.1. Purpose/Objectives of Study..................................................................................................... 3
1.2. Study Results & Recommendations ........................................................................................ 3

2. BACKGROUND OF WEST DIVIDE PROJECT ...................................................................... 4
2.1. Congressional Authorization (CRSP) ..................................................................................... 4
2.2. Previous Studies and Configurations ..................................................................................... 5

3. CRYSTAL RIVER .............................................................................................................. 5
3.1. Placita Reservoir ........................................................................................................................... 5
3.2. 4,000 AF Placita Reservoir and Hydroelectric Feasibility.............................................. 6
3.3. Hydroelectric – Run of the River Options ............................................................................. 9

4. WEST DIVIDE CREEK AND DRY HOLLOW CREEK............................................................ 13
4.1. Upper and Lower Kendig Reservoirs .................................................................................. 13
4.2. Dry Hollow Reservoir – Pump Storage Project................................................................ 14

5. PUMP STORAGE HYDROELECTRIC – COLORADO RIVER ................................................ 15
5.1. Cost, Revenue, Feasibility, Environmental........................................................................ 15

6. CRYSTAL RIVER WATER DELIVERY OPTIONS................................................................. 17
6.1. Surface Canal & Pipeline.......................................................................................................... 17
6.2. Tunnel ............................................................................................................................................ 17

7. FINDINGS AND RECOMMENDATIONS .......................................................................... 18
7.1. West Divide Project Reconfiguration Alternatives ........................................................ 18

TABLES
Table 1 Summary of Powerhouse Location Alternatives for 4,000 AF Placita Dam...... 7
Table 2 Summary of Economic Results for Powerhouse Location Alternatives for
4,000 AF Placita Dam ........................................................................................................... 7
Table 3A 4,000 AF Placita Dam Generation Estimate (125 cfs Capacity).......................... 9
Table 3B 4,000 AF Placita Dam Generation Estimate (150 cfs Capacity).......................... 9
Table 4 Summary of Alternatives for the Run of the River Option................................... 10
Table 5 Summary of Economic Results for Run of the River Alternatives..................... 10

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 Table 6 Run of the River Generation Estimate......................................................................... 11
Table 7 Summary of Economic Results for Run of the River Alternative with Flow of
160 cfs..................................................................................................................................... 12
Table 8A Run of the River Generation Estimate (160 cfs) ................................................... 12
Table 8B Run of the River Generation Estimate (250 cfs) ................................................... 12
Table 9 Operating Pumped Storage Plants in Colorado ....................................................... 17

FIGURES
Figure 1 Operating Ranges for Different Turbine Technologies.......................................... 8

APPENDICES
Appendix A – Figures
Figure 1 Crystal River Hydroelectric Projects
Figure 2 Placita Reservoir Sites – Overall Plan
Figure 2A Small Placita Reservoir – Site Plan
Figure 2B 4,000 AF Placita Reservoir – Overall Plan
Figure 3 Crystal River Flow Duration Curve above Avalanche Creek (Elevation 6920 ft)
Figure 4 Run of the River Alternative (Final)
Figure 5 West Divide Project, Colorado River Pump Station, Decreed Location, Garfield
County, Colorado

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 1. Executive Summary
1.1. Purpose/Objectives of Study
The West Divide Water Conservancy District (West Divide) and the Colorado River Water
Conservancy District (River District) seek to complete an up to date analysis of certain
components of the West Divide Project. As part of this analysis, Black & Veatch was asked to:
1. Evaluate the Operation and Feasibility of Hydroelectric Facilities.
2. Review and Update Cost Estimates for Kendig Reservoir.
3. Estimate Cost of Delivery Tunnel from the Crystal River to Kendig Reservoir.
The Hydropower Feasibility Study (Study) entailed a screening level assessment of a pump
storage project from the Colorado River to Dry Hollow Reservoir as well as a pre feasibility level
assessment of a Crystal River hydropower project using both the run of the river and Placita
Reservoir (or reservoir similar to Placita).

1.2. STUDY RESULTS & RECOMMENDATIONS
The findings of the study are:
Under current economic conditions, the hydropower projects are expected to have a
relatively low financial rate of return. The hydroelectric projects would be most
economically viable as part of a larger project.
Placita Reservoir, as originally decreed, could be difficult to construct due to relocation
of State Highway 133 and a county road, environmental concerns, and the inundation of
several houses and other private property. A smaller Placita Reservoir at the original
dam site could avoid many of these issues, but is deemed too small to be considered for
construction.
An alternative reservoir is a reduced Placita Reservoir with a capacity of approximately
4,000 acre feet located within the original inundation area of the decreed Placita
Reservoir, but with the dam located upstream of all private property. The reduced
Placita Reservoir is technically feasible from an engineering perspective; there are no
known fatal flaws.
Both Upper and Lower Kendig Reservoirs are technically feasible from an engineering
perspective; there are no known fatal flaws. Lower Kendig Reservoir is more cost
effective, but Upper Kendig Reservoir allows gravity flow discharge to the Highline Ditch.
It is technically feasible from an engineering perspective to construct a tunnel from the
reduced Placita Reservoir to Upper or Lower Kendig Reservoir; there are no known
technical fatal flaws.

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 The recommendations for future feasibility studies are:
Periodically reassess potential hydroelectric facilities to evaluate the influence of
changing power market conditions, especially in regards to the value of carbon credits
(Crystal River) and ancillary services (Colorado River). Power prices may need to
approximately double relative to construction and other costs for the hydroelectric
facilities to become economically attractive.
A more detailed study of river impacts and site geological conditions is needed to
confirm the technical feasibility of the pumped storage alternative.
Consider the current status of the Memorandum of Understanding (MOU) between the
Federal Energy Regulatory Commission (FERC) and the State of Colorado regarding the
accelerated permitting process for small hydro. This process may facilitate the
development of the Crystal River hydroelectric projects, making them more
economically attractive to energy investors.
Perform additional geotechnical investigations at the Upper Kendig Reservoir site to
further understand design and construction considerations of the site.

2. BACKGROUND OF WEST DIVIDE PROJECT
2.1. CONGRESSIONAL AUTHORIZATION (CRSP)
West Divide, a Colorado governmental entity, was organized in 1964 for the purposes of
conserving and developing land and water resources within its boundaries. The West Divide
district area includes portions of Garfield, Pitkin and Mesa Counties in Western Colorado. The
following history of the West Divide Project is from the West Divide website.
The West Divide Project was first envisioned in the late 1930s as a modest storage project to
provide supplemental irrigation water to the West Divide Creek drainage. Subsequent studies
for the West Divide Project anticipated the supply of water for municipal, domestic, industrial,
and irrigation water supplies as well as for flood control, recreation, and fish and wildlife
enhancement. An expanded service area extending beyond the West Divide Creek watershed
was also anticipated in these later studies.
The U.S. Bureau of Reclamation (USBR) included the West Divide Project in the Colorado River
Storage Projects Act (CRSP) of 1956, which gave priority to the West Divide Project for the
completion of planning reports, and named it as a participating project of the CRSP. West
Divide was formed on April 22, 1964, to provide local project sponsorship and administration of
the West Divide Project.
A feasibility report published in 1966 proposed a plan for developing irrigation, municipal, and
industrial water in the Crystal River drainage and along the Colorado River between Glenwood
Springs and DeBeque. Under this plan, principal water storage was planned for development

WEST DIVIDE PROJECT – Feasibility Assessment

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 on the Crystal River. In response to the feasibility report, Congress authorized construction of
the West Divide Project in 1966.
At the same time, opposition developed to constructing a reservoir on the Crystal River. For
these reasons, West Divide and the USBR evaluated alternate configurations of the West Divide
Project which would pump water from the Colorado River instead of diverting water by gravity
from the Crystal River. In 1982, the USBR published a planning report on the West Divide
Project that summarized these additional alternatives.

2.2. PREVIOUS STUDIES AND CONFIGURATIONS
1. U.S. Bureau of Reclamation, Region 4, West Divide Project, Colorado Feasibility Report,
March 1966.
2. Hydro Triad Ltd., Reformulation of the West Divide Project, prepared for CRWCD,
WDCD, CWCB, July 1986.
3. David E. Fleming Company, A Review of the West Divide Project, prepared for the West
Divide Water Conservancy District, January 1974.
4. U. S. Bureau of Reclamation, Data for Feasibility Design Placita Dam and Reservoir,
West Divide Project, Colorado, Grand Junction, CO February 1964.

3. CRYSTAL RIVER
3.1. PLACITA RESERVOIR
The original Placita Reservoir proposed by the USBR had a total capacity of 105,660 acre feet at
a water surface elevation of 7,690 feet. The dam was to be a rolled earth and rock fill structure
301 feet high by 1,630 feet long. The dam for this reservoir was located on the Crystal River
along State Highway 133 approximately 1.7 miles downstream of Chair Mountain Ranch. This
size reservoir is no longer believed to be economically feasible due to mitigation costs
associated with the relocation of State Highway 133 and a county road, environmental
concerns, and the inundation of several houses and other private property. Therefore, the
Placita Reservoir original size was deemed not feasible and was not investigated in this study.
A smaller Placita Reservoir at the original USBR dam site was evaluated to determine if
environmental and public issues could be minimized with a smaller storage facility. Initially, a
water surface elevation of 7,440 was investigated. This water surface elevation substantially
reduces the inundation of Highway 133, wetland areas and private property. However, the
storage capacity at this elevation is only approximately 1,400 acre feet. If the water surface is
increased to the next 40 foot contour (Elevation 7,480), the storage capacity is increased to
almost 6,000 acre feet, however, the inundation of wetland areas and private property is more
substantial at this higher elevation. Therefore, a reservoir water surface elevation of 7,440 is
needed (storage capacity of 1,400 acre feet) to avoid substantial inundation of wetlands and

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 structures. This storage capacity is deemed too small to be practicable and a smaller Placita
Reservoir at the original dam site was not investigated further.

3.2. 4,000 AF PLACITA RESERVOIR and HYDROELECTRIC FEASIBILITY
The reduced Placita Dam Storage Alternative consists of an 80 foot high dam located on the
Crystal River at Station 175 (Mile 3.3) as shown on Appendix A, Figure 1. The extent of the
4,000 acre foot reservoir is shown on Appendix A, Figure 2. This site was deemed more
feasible than the original Placita Reservoir site because many of the land issues discussed in
Section 3.1 above are avoided, for example:
Affects to riparian and wetland areas would be reduced
State Highway 133 would not require relocation; only County Road 3
No houses are expected to be relocated, only the USFS Bogan Flats Campground would
require relocation
The dam would be located on the Crystal River on County Road 3 less than 0.5 miles upstream
of Chair Mountain Ranch. The base of the dam has an elevation of 7,560 feet resulting in a
height of 80 feet. Based on 40 foot contour intervals, the reservoir total capacity at a spillway
elevation of 7,630 feet is 4,650 acre feet and the surface area is 115 acres. For the purposes of
this report, a usable reservoir volume of 4,000 acre feet was selected to evaluate hydroelectric
opportunities.
The reservoir would store water from the Crystal River basin. The spillway would likely be
constructed on the left abutment with the outlet works located near the existing stream
channel. Based on the 1966 USBR report, suitable materials for the earth and rock fill dam
embankment could be obtained within the immediate vicinity of the dam site. County Road 3
would need to be relocated for approximately 0.8 miles and would likely need to be cut into
the mountain slope on the south side of the reservoir. Approximately 75 percent of the
reservoir area contains trees that would need to be cleared and disposed. No additional
geotechnical information was obtained on the dam site for this study. Additional geotechnical
studies are recommended to ascertain further requirements for feasibility and constructability.
Hydroelectric Alternatives
Three downstream powerhouse locations were investigated to determine which location would
provide the greatest economic return. The first powerhouse location is at the base of the dam.
The other two are located shortly downstream to take advantage of additional head. Because
of the relatively mild river gradient of approximately one percent in this area, and as discussed
further in Section 3 herein, hydropower plants with significant penstock lengths were not
judged to be economical. The three alternatives are summarized in Table 1.

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 TABLE 1: SUMMARY OF POWERHOUSE LOCATION ALTERNATIVES FOR 4,000 AF PLACITA
DAM
ALTERNATIVE
NUMBER

LOCATION
(station)

POWERHOUSE
LOCATION
(station)

RESERVOIR
WATER
ELEVATION
(ft)

POWERHOUSE
ELEVATION
(ft)

GROSS
HEAD
(ft)

PENSTOCK
LENGTH
(ft)

175
175
175

175
1,050
1,275

7,640
7,640
7,640

7,560
6,500
6,240

80
1,140
1,400

50
87,500
110,000

DAM

1
2
3

Each of the three locations was analyzed using the following assumptions:
Efficiency = 85%
Generator Efficiency = 95%
Transformer Efficiency = 99%
Capacity Factor = 25%
Powerhouse Cost = $3,500/kW
Penstock Cost (48”) = $1,000/linear foot
Penstock Headloss = 5.0 ft/1,000 linear feet
The flow duration curve for the storage alternative is the purple line in Appendix A, Figure 3.
Table 2 provides a summary of the results of the site selection investigation. Based on the
above assumptions, the table shows that the base of the dam (Alternative No. 1) is the most
economical location for the powerhouse. This will be the basis for the rest of the report.

TABLE 2: SUMMARY OF ECONOMIC RESULTS FOR POWERHOUSE LOCATION ALTERNATIVES
FOR 4,000 AF PLACITA DAM
ALTERNATIVE
NUMBER

NET
HEAD
(ft)

DESIGN
FLOW
(cfs)

POWER
(kWh)

POWERHOUSE
COST

PENSTOCK
COST

TOTAL
CONSTRUCTION
COST(1)(2)

PROJECT
COST
($/kWh)

1
2
3

80
703
850

125
125
125

1,476,498
13,006,144
15,736,971

$2,359,700
$20,786,074
$25,150,410

$50,000
$87,500,000
$110,000,000

$2,409,700
$108,286,074
$135,150,410

$1.63
$8.33
$8.59

(1) Costs do not include reduced Placita Dam or interconnection costs.
(2) Non construction costs are not included.
Turbine Selection
Based on the steep nature of the flow duration curve provided for this section of the Crystal
River, it was important to select a turbine that is efficient over a large range of flows. Note that
multiple unit powerhouses can produce greater generation, but are typically less economically

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 feasible for powerhouses in this size range. Based on the combination of large flow range and
low head, an Ossberger turbine was selected. Ossberger turbines can operate down to 15% of
rated flow and the efficiency is steady across that entire flow range. Ossberger turbines also
cost less than other turbine technologies which helps to make the project more cost effective.
Figure 1 shows how the design point fits within the operating range of the Ossberger turbine.
Figure 1: Operating Ranges for Different Turbine Technologies

Economic Analysis
Based on the results of the site investigation and turbine selection, a detailed economic
evaluation was performed for Alternative 1 which located the powerhouse at the base of
reduced Placita Dam. A generation estimate was performed to determine the amount of
energy that would be produced on an annual basis for units designed for both 125 and 150 cfs.
These generation estimates were based on the flow duration curve for this section of the
Crystal River (Figure 3) and utilized the following assumptions.
Turbine Size = 676 kW (125 cfs) or 811 kW (150 cfs)
Turbine Efficiency = 85%
Generator Efficiency = 95%
Transformer Efficiency = 99%

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 The results are shown in Tables 3a and 3b.

TABLE 3A: 4,000 AF PLACITA DAM GENERATION ESTIMATE (125 CFS CAPACITY)
FLOW (cfs)

NET HEAD (ft)

POWER (kW)

PROBABILITY

HOURS

ENERGY
(MWh)

125
100
50
23
19

80
80
80
80
80

676
541
271
124
103
Operational

33%
4%
20%
19%
9%
85%

2,890
350
1,752
1,664
788
Total Energy (MWh)

1,954
189
475
206
81
2,905

TABLE 3B: 4,000 AF PLACITA DAM GENERATION ESTIMATE (150 CFS CAPACITY)
FLOW (cfs)

NET HEAD (ft)

POWER (kW)

PROBABILITY

HOURS

ENERGY
(MWh)

150
125
100
50
23

80
80
80
80
80

811
676
541
271
124
Operational

29%
4%
4%
20%
19%
76%

2,540
350
350
1,752
1,664
Total Energy (MWh)

2,060
237
189
475
206
3,167

Assuming a power value of $80/MWh, this translates to average annual revenues of
approximately $230,000 and $250,000 for the smaller and larger powerhouses respectively.
Assuming $50,000 in annual operating cost, the net annual incomes are $180,000 and
$200,000. Assuming 40% for non construction costs results in total project costs of $3.4 million
and $4.0 million. The undiscounted paybacks for these powerhouses would be 19 and 20 years.
A discounted payback which accounts for the cost of money will result in a somewhat longer
payback period.
Holy Cross Energy indicated that only single phase power extends from Highway 133 along
County Road 314 into Marble, so some line extension may be required for this project.

3.3. HYDROELECTRIC – RUN OF THE RIVER OPTIONS
Site Selection
The Run of the River Hydroelectric Alternative considered five possible combinations of dam
and powerhouse locations on the Crystal River. Elevations and distances were calculated based
on the river profile shown in Appendix A, Figure 1. The flow duration curve at the confluence
with Avalanche Creek was used to evaluate all alternatives. Each alternative assumed that a

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Page 9

 20 foot high concrete diversion dam on the Crystal River would be utilized. The five
alternatives are summarized in Table 4.

TABLE 4: SUMMARY OF ALTERNATIVES FOR THE RUN OF THE RIVER OPTION
ALTERNATIVE
NUMBER

DAM
LOCATION
(station)

POWERHOUSE
LOCATION
(station)

RESERVOIR
WATER
ELEVATION (ft)

POWERHOUSE
ELEVATION
(ft)

GROSS
HEAD
(ft)

PENSTOCK
LENGTH
(ft)

1
2
3
4
5

175
175
328
328
650

1,050
1,275
1,050
1,275
700

7,580
7,580
7,450
7,450
7,140

6,500
6,240
6,500
6,240
6,960

1011
1340
881
1210
180

87,500
110,000
72,200
94,700
5,000

Each of the five alternatives was analyzed using the following assumptions:
Turbine Efficiency = 85%
Generator Efficiency = 95%
Transformer Efficiency = 99%
Capacity Factor = 25%
Powerhouse Cost = $3,500/kW
Penstock Cost (48”) = $1,000/linear foot
Penstock Headloss = 5.0 ft/1,000 linear feet
Table 5 provides a summary of the results of the site selection investigation. Based on the
above assumptions, the table shows that locating the diversion dam and powerhouse at the
steepest part of the river is, not surprisingly, the most economical alternative (Alternative No.
5). The profile on this alternative is shown on Appendix A, Figure 1. A new flow duration curve
was developed for this specific site (Appendix A, Figure 4). This alternative will be the basis for
the rest of this report.

TABLE 5: SUMMARY OF ECONOMIC RESULTS FOR RUN OF THE RIVER ALTERNATIVES
ALTERNATIVE
NUMBER

NET
HEAD
(ft)

DESIGN
FLOW
(cfs)

POWER
(kWh)

POWERHOUSE
COST

PENSTOCK
COST

TOTAL
CONSTRUCTION
COST(1)(2)

PROJECT
COST
($/kWh)

1
2
3
4
5

643
790
589
737
155

125
125
125
125
125

11,895,299
14,626,126
10,904,795
13,635,622
2,869,683

$19,010,751
$23,375,087
$17,427,755
$21,792,091
$4,586,251

$87,500,000
$110,000,000
$72,200,000
$94,700,000
$5,000,000

$106,510,751
$133,375,087
$89,627,755
$116,492,091
$9,586,251

$8.95
$9.12
$8.22
$8.54
$3.34

(1) Costs do not include reduced Placita Dam or interconnection costs.
(2) Non construction costs are not included.

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Page 10

 Turbine Selection
Based on the steep nature of the flow duration curve, it was important to select a turbine that
is efficient over a large range of flows. Similar to the storage alternative in Section 3.2 above,
based on the combination of large flow range and low head, an Ossberger turbine was selected.
Economic Evaluation
Based on the results of the site investigation and turbine selection, a detailed economic
evaluation was performed for Alternative 5 which located the diversion dam and powerhouse
at the steepest section of the Crystal River. A generation estimate was performed to determine
the amount of energy that would be produced on an annual basis. The generation estimate
was based on the flow duration curve for the “Above Avalanche Creek” section of the Crystal
River and utilized the following assumptions. The results are shown in Table 6.
Turbine Size = 1,310 kW
Turbine Efficiency = 85%
Generator Efficiency = 95%
Transformer Efficiency = 99%

TABLE 6: RUN OF THE RIVER GENERATION ESTIMATE
FLOW (cfs)

NET HEAD (ft)

POWER (kW)

PROBABILITY

HOURS

ENERGY
(MWh)

125
110
75
50
19

155
155
155
155
155

1,310
1,153
786
524
199
Operational

32%
3%
5%
5%
18%
63%

2,803
263
438
438
1,577
Total Energy (MWh)

3,673
303
344
230
314
4,864

After the initial economic evaluation, an attempt was made to optimize the potential power
generation by increasing the rated flow for the turbine. It was determined that a rated flow of
160 cfs would provide a higher amount of power generation for a similar construction cost.
The results of the economic analysis for the 160 cfs turbine are shown in Table 7.

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 TABLE 7: SUMMARY OF ECONOMIC RESULTS FOR RUN OF THE RIVER ALTERNATIVE WITH
FLOW OF 160 CFS
ALTERNATIVE
NUMBER

NET
HEAD
(ft)

DESIGN
FLOW
(cfs)

POWER
(kWh)

POWERHOUSE
COST

PENSTOCK
COST

TOTAL
CONSTRUCTION
COST(1)(2)

PROJECT
COST
($/kWh)

6

140

160

3,317,724

$5,302,298

$5,000,000

$10,302,298

$3.11

(1) Costs do not include reduced Placita Dam or interconnection costs.
(2) Non construction costs are not included.
Since the resulting unit cost was lower for 160 cfs, a 250 cfs alternative was also evaluated.
These detailed calculations are shown in Tables 8a and 8b.

TABLE 8A: RUN OF THE RIVER GENERATION ESTIMATE (160 CFS)
FLOW (cfs)

NET HEAD (ft)

POWER (kW)

PROBABILITY

HOURS

ENERGY
(MWh)

160
130
100
55
24

140
140
140
140
140

1,515
1,231
947
521
227
Operational

28%
3%
3%
9%
18%
61%

2,453
263
263
788
1,577
Total Energy (MWh)

3,716
323
249
411
358
5,057

TABLE 8B: RUN OF THE RIVER GENERATION ESTIMATE (250 CFS)
FLOW (cfs)

NET HEAD (ft)

POWER (kW)

PROBABILITY

HOURS

ENERGY
(MWh)

250
200
160
130
100
55
38

125
125
125
125
125
125
125

2,117
1,694
1,355
1,231
1,101
466
322
Operational

22%
3%
3%
3%
3%
9%
8%
51%

1,927
263
263
263
263
788
701
Total Energy (MWh)

4,080
445
356
323
289
367
226
6,086

Assuming a power value of $80/MWh, these alternatives translate to average annual revenues
of approximately $400,000 and $490,000 respectively. Assuming $100,000 in annual operating
costs, the net annual incomes are $300,000 and $390,000. Assuming 40% for non construction
costs results in a total project costs of $14.4 and $17.3 million. The undiscounted payback for
these powerhouses would be 36 and 35 years, which is essentially identical for this level of
study.

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 Holy Cross Energy indicated that of the three hydropower projects, this project was of the most
interest because its size and proximity to three phase power of sufficient capacity makes it
readily integratable into their system. Currently Holy Cross is purchasing renewable power
such as this in the $80 to $90/MWh range, consistent with the assumption of this study. From
their point of view, future energy pricing is largely dependent on future valuation of carbon
credits.

4. WEST DIVIDE CREEK and DRY HOLLOW CREEK
4.1. UPPER AND LOWER KENDIG RESERVOIRS
Upper and Lower Kendig Reservoirs are located on West Divide Creek 12 to 14 miles south of
Silt, Colorado. Water in West Divide Creek is primarily used for irrigation of agricultural lands.
The reservoirs were previously proposed because the distribution of annual flows does not
coincide with the distribution of annual demand. The reservoirs would store the early summer
peak flows which would allow late season irrigation demands to be met more frequently; thus,
shortages are reduced and yields are improved. The storage could also be used to supply non
irrigation demands. Only one of the reservoirs would be constructed.
Lower Kendig Reservoir is located at the original Kendig dam site proposed by the USBR (1966).
The dam is located downstream of the Highline Ditch diversion. Upper Kendig Reservoir was
proposed in the 1986 Hydro Triad report. The Upper Kendig Reservoir dam site is located
approximately 1.7 miles upstream of the Lower Kendig dam site. The Upper Kendig dam site
was selected so the stored water could be released by gravity to the Highline Ditch. The
Highline Ditch is a major irrigation ditch in the West Divide Creek basin.
The 1986 Hydro Triad report found that no major deposits of hard rock suitable for rockfill
dams are present in the area. Therefore, only an earthfill dam and a roller compacted concrete
(RCC) dam were evaluated for the Upper and Lower Kendig dams by Hydro Triad. The
materials for construction for an earthfill dam or RCC dam could likely be developed locally
from the alluvium, debris flows, or landslide. Hydro Triad concluded that the geology for the
Upper Kendig site is similar to the Lower Kendig site, but recommended that preliminary
geotechnical investigations be performed on the Upper site to confirm feasibility of the site.
The preliminary geotechnical investigations would include topographic and geologic mapping of
the dam alignment and reservoir, core drilling, sampling, hydro geological testing in holes along
the dam axis, and evaluation and testing of local sources of construction materials.
Hydro Triad laid out three different dam sizes at each of the two Kendig sites. The reservoir
capacities at Lower Kendig were 25,000 acre feet, 18,000 acre feet, and 11,000 acre feet. The
reservoir capacities at Upper Kendig were 18,300 acre feet, 13,900 acre feet, and 6,100 acre
feet. The intermediate size embankment dam at Lower Kendig (18,000 acre feet) is the same

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 size embankment that was studied extensively by the USBR in 19821. The preferred storage
size based on demands and available streamflow is the 18,000 acre foot reservoir.
The Lower Kendig reservoir would require relocation of a buried natural gas pipeline. Both
reservoirs would require relocation of the county road.
The 1986 Hydro Triad report found that an RCC dam would cost 30 to 50 percent more than an
earthfill embankment for the 18,000 acre foot dam size. The Hydro Triad report also made the
following conclusions:
Several reservoirs in addition to Upper and Lower Kendig reservoirs were studied. The
most efficient storage sites were Upper and Lower Kendig because they controlled the
greatest drainage areas. Upper Kendig Reservoir allows discharges to gravity flow to the
Highline Ditch.
The most efficient reservoir size (considering acre foot of storage vs. acre foot of yield)
was 8,000 acre feet (100 percent efficiency). The efficiency gradually dropped as the
reservoir size increased to an efficiency of 55 percent for a 25,000 acre foot reservoir.
Lower Kendig is the most cost effective storage location. Small reservoirs at the Lower
Kendig site are more cost effective than larger reservoirs.
In 1986 dollars (Denver CCI of 3,503), the 18,000 acre foot reservoir (embankment dam)
cost at Lower Kendig was $20.5 million and the cost at Upper Kendig was $33.2 million.
Adjusting these costs for inflation to 2011 dollars (Denver CCI of 6,835), the cost for Lower
Kendig would be approximately $40 million and the cost for Upper Kendig would be $65
million.

4.2. DRY HOLLOW RESERVOIR – PUMP STORAGE PROJECT
In this section, a pump storage alternative from the Colorado River to Dry Hollow Reservoir is
evaluated. Both a pipeline along the originally planned approximately 16 mile Dry Hollow
Feeder Canal and a 7 mile long tunnel from the Colorado River to Dry Hollow Reservoir were
evaluated.
While pumped storage projects are net consumers of energy with overall efficiencies of about
75%, their economic feasibility is derived from one or more of the following considerations:
Energy Peak energy prices are significantly higher than off peak prices
Capacity The power grid requires readily dispatchable energy
Ancillary Services – The power grid needs stability

1

U. S. Bureau of Reclamation, “Planning Report on the West Divide Project, Colorado,” May 1982.
WEST DIVIDE PROJECT – Feasibility Assessment

Page 14

 Often pumped storage is considered in conjunction with base load projects (e.g. nuclear) to
provide peak power or with sporadic sources such as wind, which tends to generate more
energy at night when less power is required.
The diversion point for the pumped storage alternative is located on the Colorado River
approximately 3 miles downstream from New Castle, Colorado. A diversion of 250 cfs was
adjudicated for this site. Because the associated upper storage reservoir, Dry Hollow, is about
580 feet (6,120 – 5,540) above the elevation of the Colorado River, the possibility of pumped
storage between these two water sources exists.
As a practical matter, however, the distance between the sources greatly exceeds the typical
range for economically feasible pumped storage sites. An initial assessment of pumped storage
is often conducted by evaluating the L/H ratio, i.e. the distance between the water sources (L)
divided by the elevation difference (H). Economically feasible sites tend to have an L/H ratio of
less than 10. Of all the active pumped storage sites in the United States in 1992, none had an
L/H lower than 39.2 This is because long pressure pipes between the water sources both are
costly and also consume valuable pressure head.
The L/H ratio for a 7 mile tunnel project would be about 60. A pressure pipe along the
originally planned approximately 16 mile Dry Hollow Feeder Canal would have an L/H of about
150. Neither of these two projects can be expected to be economically feasible under existing
conditions. Therefore, no further investigations for this alternative were completed.

5. PUMP STORAGE HYDROELECTRIC– COLORADO RIVER
5.1. COST, REVENUE, FEASIBILITY, ENVIRONMENTAL
As discussed above, pumped storage feasibility is dependent on a low L/H ratio. This is
normally accomplished by connecting the two water sources by a relatively short, steep
penstock. Using the Colorado River as a water source, this could be achieved by constructing
an upper reservoir (Jolley Mesa Reservoir) on the mesa immediately above the left (south) bank
of the river.
From a topographic perspective, this reservoir could be created as shown on Appendix A,
Figure 5 using an earth embankment. The resulting L/H is 980/5000, or approximately 5, which
is generally considered a good ratio. A slightly lower L/H could be achieved by placing a ring
reservoir closer to the intake site, but the additional cost of the reservoir is expected to exceed
the value of the additional energy.

2

American Society of Civil Engineers, Task Committee on Pumped Storage, Compendium of Pumped Storage Plants
in the United States, New York, 1993.

WEST DIVIDE PROJECT – Feasibility Assessment

Page 15

 Pumped storage projects typically have a target production period of 4 to 12 hours during a
daily cycle, corresponding to periods of peak energy prices. Assuming an 8 hour generation
period, 16 hours is available for pumping. At 250 cfs, the total storage volume required in the
Jolley Mesa Reservoir would be
V = (16 hrs) * (250 cfs) * (3600 sec/hr) / (43,560 sq ft/ac) = 330 acre feet
Assuming 10% energy loss in the penstock and 87% overall generation efficiency, the generator
size would be:
P = 0.87(500)0.9(980)
11,700

40 MW

Forty megawatts represents about the smallest practical size for pumped storage projects,
which typically range from 100 to 1,000 MW. However, projects of this size do exist, often
because the Federal Energy Regulatory Commission (FERC) allows license exemptions for
municipalities for projects up to 40 MW.
Assuming that project economics would be driven by energy pricing and that the peak/off peak
differential is as follows:
Peak: $120/ MW hour
Off Peak: $60/MW hour
The net annual revenue from the project would be approximately:
R = (8 hrs/day * 365 days/yr * 40 MW * $120/MW hr) – (16 hrs/day * 365 days/yr * 20
MW / (0.9*0.87) * $60/MW hr)

$5,100,000

Assuming $400,000 in annual operating costs would result in a net annual revenue of $4.7
million.
Assuming construction costs of $3,000/kW and 40% non construction costs results in an overall
project cost of $168 million (costs include diversion, powerhouse, piping, tunnel, and reservoir).
The undiscounted payback would be approximately 28 years.
Holy Cross indicated that their current contract with Excel Energy covers their energy load
following needs (generation and energy demand are closely matched), so that a pumped
storage project would not be attractive to them today. Larger utilities such as Excel may see
greater value in a project of this type due to their own internal needs to balance wind and
other intermittent sources of energy within their large system. There are three operating and
one proposed pumped storage plants in Colorado:

WEST DIVIDE PROJECT – Feasibility Assessment

Page 16

 TABLE 9. OPERATING PUMPED STORAGE PLANTS IN COLORADO
NAME

YEAR
BUILT

L/H

POWER
SELLER

CAPACITY
(MW)

Flatiron
Cabin Creek
Mount Elbert

1954
1967
1981

26
4
7

WAPA
Excel
WAPA

9
300
200

The Phantom Canyon project is proposed.

6. CRYSTAL RIVER WATER DELIVERY OPTIONS
6.1. SURFACE CANAL & PIPELINE
The original West Divide Project proposed using the Huntsman Canal to divert water from the
Crystal River to West Divide Creek. In addition, the Four Mile Canal and Siphon and the
Avalanche Canal and Siphon were proposed to divert water from the Crystal River to the West
Divide Creek basin. The canals were originally laid out as a gravity flow surface canal which
would allow water to be conveyed to the lower Kendig Reservoir. An additional option for
transferring water from the Crystal River to the Kendig Reservoirs is by a gravity flow tunnel
along an alternate alignment as described in the next section.

6.2. TUNNEL
As an alternative to the Huntsman Canal in the original West Divide Project, a single tunnel was
investigated. The tunnel would begin at reduced Placita Reservoir (low water elevation of
7,560 ft) and end at Upper Kendig Reservoir (high water elevation of 7,200 ft). The tunnel’s
hydraulic grade line slope would be 0.3% over its 23 mile length. It was assumed up to 300 cfs
would be transferred through the tunnel. A finished tunnel diameter of 7 feet (84 inches) was
selected resulting in a velocity of approx. 8 ft/sec at 300 cfs.
The following assumptions were used to evaluate the tunnel and determine the cost:
Consistent, hard rock.
Cover on the tunnel ranges from 900 feet to 3,700 feet.
A tunnel boring machine (TBM) would be used to drill the tunnel. The TBM would drill a
10 foot diameter tunnel.
The tunnel would be concrete lined to a finished diameter of 7 feet.
TBM average progress per day of 100 feet. The tunnel contract would be split into three
contracts (each approximately 7.7 miles). The total construction time would be
approximately 18 months if all three contracts were executed concurrently.
Vertical shafts are included for ventilation and tunnel access.
Tunnel costs are based on the finished tunnel diameter.

WEST DIVIDE PROJECT – Feasibility Assessment

Page 17

 Based on the above assumptions, a tunnel construction cost of $25/diam in/ft, a 30%
construction contingency, and a 25% engineering, permitting and approvals contingency, the
resulting total tunnel cost would be approximately $395 million.

7. FINDINGS AND RECOMMENDATIONS
7.1. WEST DIVIDE PROJECT RECONFIGURATION ALTERNATIVES
Under existing economic conditions, the undiscounted payback of the hydroelectric
alternatives would range from approximately 19 years to 36 years.
Placita Reservoir, as originally decreed, could be costly to construct due to relocation of
State Highway 133 and a county road, and mitigation expenses associated with the
inundation of wetlands, several houses, private property and Bogan Flats campground.
A smaller Placita Reservoir at the original dam site is deemed too small to be considered
for construction.
A reduced Placita Reservoir is a 4,000 acre foot reservoir located within the original
inundation of the large Placita Reservoir, but the dam is located upstream of Chair
Mountain Ranch. The reduced Placita Reservoir is technically feasible from an
engineering perspective; there are no known fatal flaws.
Both Upper and Lower Kendig Reservoirs are technically feasible from an engineering
perspective; there are no known fatal flaws. Lower Kendig Reservoir is more cost
effective, but Upper Kendig Reservoir allows gravity flow discharge to the Highline Ditch.
It is technically feasible from an engineering perspective to construct a tunnel from the
reduced Placita Reservoir to Upper or Lower Kendig Reservoir; there are no known fatal
flaws.
We recommend the following actions to further assess the feasibility of the West Divide Project
and its components:
Reassess projects in the near future based on current power market conditions,
especially in regards to the value of carbon credits (Crystal River) and ancillary services
(Colorado River). Energy prices will likely need to approximately double relative to
construction and other costs for these projects to become economically attractive.
Prepare a more detailed study of river impacts and site geological conditions to confirm
the technical feasibility of the pumped storage alternative.
Consider the current status of the Memorandum of Understanding (MOU) between the
Federal Energy Regulatory Commission (FERC) and the State of Colorado regarding the
accelerated permitting process for small hydro. This process being in place and running
efficiently would speed the development of the Crystal River projects, making them
more economically attractive to energy investors.

WEST DIVIDE PROJECT – Feasibility Assessment

Page 18

 Perform additional geotechnical investigations at the Upper Kendig Reservoir site to
confirm feasibility of the site.

WEST DIVIDE PROJECT – Feasibility Assessment

Page 19

 Crystal River Hydroelectric
Projects

Elevation (ft)

Crystal River Elevation Profile

8000
7975
7950
7925
7900
7875
7850
7825
7800
7775
7750
7725
7700
7675
7650
7625
7600
7575
7550
7525
7500
7475
7450
7425
7400
7375
7350
7325
7300
7275
7250
7225
7200
7175
7150
7125
7100
7075
7050
7025
7000
6975
6950
6925
6900
6875
6850
6825
6800
6775
6750
6725
6700
6675
6650
6625
6600
6575
6550
6525
6500
6475
6450
6425
6400
6375
6350
6325
6300
6275
6250
6225
6200
6175
6150
6125
6100
6075
6050
6025
6000

Res
NWS El. 7640

Turbine
El. 7550 ft

Run of River Diversion Dam
El. 7140 ft.

Penstock
L=5000 ft.

Turbine
El. 6960 ft

Avalanche Power Plant Turbine
El. 6500 ft.

Nettle Creek Turbine
El. 6240

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21 21.5 22 22.5 23 23.5 24 24.5 25 25.5 26 26.5 27 27.5 28 28.5 29 29.5 30 30.5 31 31.5 32
Distance from Beginning (mi)

Figure
1