HomeMy WebLinkAboutCalifornia Creek Hydroelectric Feasibility Preliminary Engineering Analysis and Environmental Review - Mar 2011 - REF Grant 2195422Sponsored by the Alaska Energy Authority
California Creek Hydroelectric
Feasibility
Preliminary Engineering Analysis and Environmental Review
March 2011
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A c k n o w l e d g e m e n t s
Alaska Green Energy, LLC received a grant from the Alaska Energy Authority to conduct a feasibility study for
hydroelectric power generation on California Creek in Girdwood, Alaska. Specialists from the University of Alaska
Anchorage, School of Engineering were contracted by Alaska Green Energy to prepare a preliminary engineering
investigation and a separate preliminary environmental review. The report summarizes the measures taken for and
findings of those studies.
The Preliminary Engineering Analysis was completed by the UAA School of Engineering, whose efforts were led by
Orson P. Smith, PE, Ph.D., in collaboration with fellow faculty members John Bean, PE (Maine), Muhammad Ali,
Ph.D., and Sun-il Kim, Ph.D. Cheyenne Alabanzas also contributed to the project as an undergraduate mechanical
engineering student during the summer following her graduation.
The Preliminary Environmental Review was for the most part completed on April 19, 2010 by Grant Lindren as an
academic assignment while enrolled in the UAA graduate course AEST A607 Environmental Permitting Project. His
report was later supplemented with additional information by individuals from Alaska Green Energy, LLC.
Besides the Environmental Review, other portions of the report were also completed by individuals from Alaska
Green Energy, LLC. Those included: Richard Stryken, Bob Gross, Murph OBrien, and Ron Swanson.
Thanks also go to the staff of the Alaska Energy Authority for providing the funding for this report and their assistance
along the way.
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CALIFORNIA CREEK HYDROELECTRIC FEASIBILITY
P r e l i m i n a r y E n g i n e e r i n g A n a l y s i s a n d E n v i r o n m e n t a l R e v i e w
T a b l e o f C o n t e n t s
ACKNOWLEDGEMENTS .................................................................................... I
TABLE OF CONTENTS ...................................................................................... II
UNIT CONVERSION TABLE ............................................................................. III
EXECUTIVE SUMMARY .. 1
INTRODUCTION ............................................................................................ 3
SURVEYING AND MAPPING ............................................................................. 7
HYDROLOGICAL INVESTIGATIONS ................................................................... 11
SURFICIAL GEOLOGY .................................................................................... 20
PROSPECTIVE INTAKE SITES AND PENSTOCK ROUTES ......................................... 21
ELECTRO-MECHANICAL CONCEPTUAL DESIGN ................................................. 31
PRELIMINARY ELECTRICITY COST ANALYSIS .................................................... 42
PRELIMINARY ENVIRONMENTAL REVIEW . ..44
CONCLUSIONS AND RECOMMENDATIONS ......................................................... 49
REFERENCES ................................................................................................. 50
A p p e n d i c e s
APPENDIX LISTING .................................................................................... A-1
MEETINGS AND PRESENTATIONS TO DATE ..................................................... A-2
SAMPLE CALCULATIONS WITH FIXED (CONSTANT) FLOW RATE
OF 5CFS (475 FT, GROSS HEAD) ........................................................... A-3
SAMPLE CALCULATIONS WITH FIXED (CONSTANT) FLOW RATE
OF 5CFS (325 F. GROSS HEAD) ............................................................ A-4
AMORITIZATION CHART FOR ECONOMMIC ANALYSIS .................................... A-5
ECONOMIC AALYSIS AND AMORITIZATION CHART (GROSS HEAD,325 FT.) ....... A-8
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PRICE QUOTE AND SPECIFICATIONS OF PELTON WHEEL ................................. A-11
HDPEPIPE;TYPICAL DIMENSIONS AND ASSOICATED PRESSURE RATING ......... A-13
STEEL PIPE BLACK AND ZINC COATED,WELDED CONFORMING
TO A53-1993 ................................................................................... A-14
INDEX MAP OF HORIZONTAL CONTROL POINT POSITIONS
ALONG CALIFORNIA CREEK ................................................................ A-15
COORDINANTES OF SURVEY POINTS SET ALONG CALIFORNIA CREEK ................ A-17
L i s t o f F i g u r e s
1. LOCATION AND VICINITY MAP ................................................................... 4
2. AERIAL PHOTO OF CALIFORNIA CREEK DRAINAGE BASIN . .. 5
3. DEVELOPMENTS PROPOSED IN THE CROW CREEK
NEIGHBORHOOD LAND USE PLAN .............................................................. 6
4. GPS CENTRAL NETWORK FOR SURVEYS ALONG CALIFORNIA
CREEK IN 2010 .......................................................................................... 8
5. LEVEL LOOP AND TRAVERESE LOCATIONS FOR CALIFORNIA
CREEK IN 2010 ........................................................................................ 9
6. IMAGE OF DIGITAL TERRAINE MODEL DERIVED FROM
FIELD MEASUREMENTS AND DATA ............................................................ 10
7. HOBO U2 WATER LEVEL LOGGER ........................................................... 11
8. STREAM GAGE STILLING WALL .................................................................. 12
9. LOCATION OF STREAM GUAGE AND CALIFORNIA
CREEK BOUNDARIES ................................................................................ 13
10. STREAM GUAGE LOCATION WITH REFERENCE TO USGS
TOPOGRAPHIC MAP FEATURES ................................................................. 14
11. CROSS SECTION CREEK FLOW MEASUREMENTS
OF CALIFORNIA CREEKAPRIL 9, 2010 ...................................................... 14
12. ELEVATION ACROSS CALIFORNIA CREEK AT STREAM GUAGE
SITE JUNE 5, 2010 ................................................................................ 15
13. FLOW AREA AND ESTIMATED DISCHARGE VS DEPTH
AT CALIFORNIA CREEK GUAGE .................................................................. 15
14. CALIFORNIA CREEK STAGE AND DISCHARGE TIME
SERIES APRIL 9,2010 TO AUGUST 20, 2010 ................................................. 16
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15. GLACIER CREEK USGSGUAGE NO. 1527550: DATA
AUGUST 1,1965 TO SEPTEMBER 30,1978 .................................................... 17
16. FLOOD FEQUENCY FOR CALIFORNIA CREEK ESTIMATED
BY GLASS & BABETS (1987) ...................................................................... 18
17. DERIVED MEAN ANNUAL HYDROGRAPH FOR CALIFORNIA CREEK ................ 19
18. CALIFORNIA CREEK ESTIMATED AVERAGE FLOW FREQUENCY ....................... 19
19. UPPER SITE PROPOSED FOR DIVERSION OF FLOW BETWEEN TWO
WATERFALLS IN THE CHUGACH STATE PARK PORTION OF THE
CALIFORNIA CREEK CHANNEL ................................................................... 21
20. PROPOSED ALTERNATIVE ROUTES FOR PENSTOCK PIPE FROM
INTAKE TO POWERHOUSE ......................................................................... 22
21. PROPOSED INTAKE CONFIGURATION AT THE UPPER SITE .............................. 23
22. PREFABRICATED CONCRETE DROP INLET CONCEPT ..................................... 24
23. CONCEPTUAL PROFILE VIEW OF A POWER CANAL (DIVERSION
CHANNEL) AT THE UPPER INTAKE SITE ....................................................... 25
24. CONCEPTUAL PLAN FOR A POWER CANAL AT THE UPPER INTAKE SITE ............ 26
25. SCHEMATIC DIAGRAM OF TYPICAL COMPONENTS OF A HIGH-HEAD
FLOW MICRO-HYROPOWER SYSTEM ......................................................... 27
26. PROFILE PROPOSED FOR THE PENSTOCK ROUTE FROM THE
UPPER INTAKE SITE TO THE POWERHOUSE .................................................. 28
27. PROPOSED ALTERNATIVE INTAKE SITE JUST BELOW THE
BOUNDARY BETWEEN HERITAGE LAND BANK PROPERTY
&CHUGACH STATE PARK ........................................................................ 30
28. PROFILE OF PENSTOCK ROUTE FROM LOWER ALTERNATIVE INTAKE SITE ........ 30
29. TURBIN SELECTION CHART BASED ON FLOW RATE VS DISCHARGE ................ 33
30. TURBIN SELECTION CHART BASED ON NET AVAILABLE
HEAD VS DISCHARGE .............................................................................. 33
31. SCHMATIC OF THE CORSS-SECTION OF A PELTON WHEEL ............................. 34
32. TYPICAL MICRO-HYDRO INSTALLATION SCHEMATIC .................................. 35
33. RELATIVE VELOCITIES OF THE JET ON THE PELTON SHEEL BUCKET .................. 37
34. UPPER INTAKE STRUCTURE: ESTIMATED ANNUAL OUTPUT OF
489,224 KWH WITH 5 CFS WATER FLOW MINIMUM OBSERVED ..................... 38
35. UPPER INTAKE STRUCTURE: VERTICAL LINE AT 55% IS
WHERE THE FLOW RATE IS AT 5 CFS ........................................................... 39
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36. LOWER INTAKE STRUCTURE:ESTIMATED ANNUAL OUTPUT OF
309,600 KWH WITH 5 CFS WATER FLOW MINIMUM OBSERVED ..................... 40
37. LOWER INTAKE STRUCTURE: VERTICAL LINE AT 55% IS
WHERE THE FLOW RATE IS AT 5 CFS ........................................................... 41
L i s t o f T a b l e s
1. FLOW CROSS-SECTION & CURRENT MEASUREMENTS & FLOW
COMPUTATIONS; CALIFORNIA CREEK STREAM GUAGE ................................. 13
2. COORDINATES OF ALTERNATIVE INTAKE, POWERHOUSE,
AND STREAM GUAGE SITES ... .. 28
3. GROUPS OF IMPULSE AND REACTION TURBINS ............................................ 31
4. RANGES OF HYDROLOGIC HEAD SUTIABLE FOR
VARIOUS TYPES OF TURBINS ..................................................................... 32
U n i t s C o n v e r s i o n Table
US Customary Multiply by SI (metric)
foot (ft) 0.3048 meter (m)
mile (mi) 1.609 kilometer (km)
square mile (m2) 2.590 square kilometer (km2)
cubic feet per second (cfs, ft3/sec) 0.02832 cubic meters per second (m3/sec)
gallons per minute (gpm) 0.06308 liters per second (l/sec)
temperature, F (Fahrenheit) C (Celsius)
March 2011 1 California Creek Hydroelectric Feasibility E x e c u t i v e S u m m a r y
An investigation of potential hydroelectric power generation on California Creek in Girdwood, Alaska, was
conducted by the University of Alaska Anchorage, School of Engineering (UAA) for Alaska Green Energy, LLC,
sponsored by a grant from the Alaska Energy Authority. Residential developments in the vicinity are currently
planned on land managed by the Heritage Land Bank of the Municipality of Anchorage at a scale that could benefit by
low-impact renewable energy to supplement commercial power purchased from Chugach Electric Association.
The financial resources provided by Alaska Energy Authority with this grant were only sufficient for a preliminary
engineering analysis, and an environmental investigation overview. This report must be followed by additional
measurements and analyses before a final engineering design can be formulated. Likewise, a complete environmental
assessment (including field work, particularly related to identifying the habitat and possible impact of fish resources)
must also be completed to determine all the possible environmental impacts a project such as this could entail.
California Creek has a drainage area of approximately 7 square miles. Stream gauge measurements indicate a
minimum of 5 cubic feet per second (cfs) will maintain fish habitat. Average summer peak flow of 30 cfs can be
anticipated. Flows in excess of 5 cfs are anticipated to occur April to October, or about 55 percent of the entire year.
Topographic surveys along the waterway were conducted with a view toward identifying prospective intake sites,
penstock routes and power plant locations. Survey control points were discretely placed to accommodate future
refinements of topographic measurements and to support construction. Two intake sites were investigated in this
study, though other practicable intake sites may exist along the creek channel.
An upper site inside Chugach State Park beyond the Heritage Land Bank boundary was identified that takes advantage
of the steepest terrain of the drainage. This intake site accommodates a drop-inlet diversion located in a pool that
could be enhanced between two natural waterfalls. A 5,100-ft 14-inch diameter penstock could provide 475 ft gross
head to a powerhouse near the stream gauge location. This design would accommodate up to 700 kW of power
generation at a flow diversion of 25 cfs.
A lower intake site within Heritage Land Bank property accommodates a similar drop-inlet diversion apparatus or an
alternative open channel diversion structure. A 3,050-ft 14-inch diameter penstock would deliver 325 ft gross head
to a powerhouse near the stream gauge location. This design would accommodate generation of up to 400 kW at a
flow diversion of 25 cfs.
A preliminary environmental review indicates that a minimum, coastal zone management, water rights, fish habitat,
Corp of Engineers, US Fish & Wildlife Service, National Marine Fisheries Service and Federal Energy Regulatory
coordination of permits will be required, among other permissions including that of the land owners (Heritage Land
Bank and possibly Chugach State Park). Further environmental analysis and field work will be required to further
define and refine all environmental issues and possible impacts to refine all permit application processes, particularly
as it relates to fisheries resources. The environmental and permitting processes require public review and
involvement with the various representative entities involved with land use and development planning in the
Girdwood Valley.
Given the financial limitation to prepare this report, indications are that hydroelectric power generation on California
Creek appears to be a good investment and worthy of further investigation for the sake of residents of future
March 2011 2 California Creek Hydroelectric Feasibility developments proposed in the immediate vicinity, as well as for reducing regional dependency on increasingly
expensive natural gas. At present consumer prices charged by Chugach Electric Association, costs for construction
(absent any major environmental issues) should be able to be recovered in about 9 to 12 years, less than half the
service life of major components. In addition, a small hydropower development on California Creek could reduce
power costs for local residents.
The current Chugach Electric policy of paying a minimum avoided rate of power generation is lawful, but a change to
a net metering policy, as increasingly practiced elsewhere in the world, would help assure that small-scale renewable
energy systems are developed from the abundant opportunities in south-central Alaska.
March 2011 3 California Creek Hydroelectric Feasibility I n t r o d u c t i o n
Girdwood is a town located in a picturesque alpine valley of coastal rain forest 40 miles south of Anchorage, Alaska
(see Figures 1 and 2). Girdwood is an outlying community within the Municipality of Anchorage and presently has a
population just above 2,000 permanent residents. The population of Girdwood has increased over the past decade
and is expected to continue to do so in the future. According to the Alaska Department of Labor and Workforce
Development, the population of Girdwood doubled between 1980 and 2000. The Girdwood population of Girdwood
full-time residents is projected to grow to almost 4,000 residents by 2020, increasing the expected electricity
demand in the area.
HLB intends to develop a significant portion of its Girdwood land, and to this end initiated the Crow Creek
Neighborhood Land Use Plan (Agnew-Beck, 2006). California Creek (a tributary of Crow Creek) is part of area the
proposed residential development included in this plan. Areas near California Creek called the North and South Fans
(see Figure 3), most of which are within ¼ mile of the Girdwood town center and school, are designated in the plan
for single and multifamily housing. Adjacent HLB property may also be developed for housing.
Residences built near California Creek could be provided with power from clean, renewable hydroelectric power for
at least half the year when flows are sufficient both to maintain creek side habitats and to allow diversion of flow
above the habitat minimum for power generation. All water diverted for power generation would be cleanly returned
to the natural channel.
The community is represented by the following groups in its local planning and governance: Girdwood Advisory
Land Use Committee, Girdwood Planning and Zoning Commission, Girdwood Board of Supervisors, Heritage Land
Bank Advisory Commission, and the Anchorage Assembly. The Heritage Land Bank (HLB) manages over 5,000 acres
of uncommitted municipal land in the Girdwood Valley. HLB issued a permit to UAA for access to HLB-managed
land along California Creek for the investigation needed for this report.
The Chugach Electric Association is the utility that provides electrical power to Girdwood, primarily from generation
plants powered by natural gas. The regional natural gas supply is dwindling, according to many recent public reports
and residents are concerned about future power supply and costs. A low-impact micro-hydroelectric project with a
capacity of about 125 kW would provide renewable energy sufficient for at least 40 households in Girdwood, which
is the approximate scale of residential developments contemplated along California Creek.
Girdwood residents take pride in the stewardship of their beautiful local setting and generally strive for sustainable
living. Studies are presently underway which are investigating the feasibility of renewable energy in a variety of forms
in Girdwood Valley. This study considers hydroelectric power generated from California Creek, which could
supplement power purchased from Chugach Electric and reduce the annual cost of energy for Girdwood residents.
HLB sponsored a previous study of hydroelectric power on California Creek (Yanity 2007), upon which this
investigation expands.
March 2011 4 California Creek Hydroelectric Feasibility
F IGURE 1. L OCATION AND V ICINITY M AP .
March 2011 5 California Creek Hydroelectric Feasibility
F IGURE 2. A ERIAL PHOTO OF C ALIFORNIA C REEK DRAINAGE BASIN (PHOTO SOURCE : M UNICIPALITY
OF A NCHORAGE )
March 2011 6 California Creek Hydroelectric Feasibility F IGURE 3. D EVELOPMENTS PROPOSED IN THE C ROW C REEK N EIGHBORHOOD L AND U SE P LAN
(A GNEW -B ECK , 2006), WITH LOW - AND MEDIUM -DENSITY RESIDENTIAL NEIGHBORHOODS BY
C ALIFORNIA C REEK .
March 2011 7 California Creek Hydroelectric Feasibility S u r v e y i n g a n d M a p p i n g
Field surveys and mapping were accomplished by UAA faculty and students to support the feasibility study of micro-
hydro power on California Creek. When developing a micro-hydropower site, a critical early step in the process is to
determine the elevation drop and terrain characteristics of the stream and surrounding area in question (Inverson
1986). Inlet site location, static head determination, terrain familiarization and characterization, pipe routing,
powerhouse location and stream gauge location were all supported by surveying and mapping efforts documented
below.
The survey resulted in 64 survey points being set on site, available for future use. Most points are comprised of a 30-
inch section of reinforcing bar, driven flush with the ground. Approximately two-thirds of the points have been
located three-dimensionally. All points having approximate GPS coordinates and most have swing ties, reference
points set in the field for easy recovery of the point.
Control was set using carrier-phase GPS (Hull, 1988), also known as geodetic GPS. Survey points AKDOTPF GPS
23 and AKDOTPF GPS 22 (Figure 4) in Girdwood and the Continuously Operating Reference Stations (CORS, Snay
& Soler 2008) at the University of Alaska Anchorage were used as control references.
A level run was conducted (Figure 5), starting at the bridge over California Creek on Crow Creek Road, running
along the hiking trail (stations CC201-CC206) thence cross-country to the power house site and stream gauge
location (CC1, GP04). The leveling then proceeded cross-country to regain the foot path at station CC3, continuing
to station CC14 then to stations CC115 to CC123 and control stations GP05 and GP06. Trigonometric leveling was
extended from station CC122 to stations CC223 through CC231, the terminating station of the project, as well as a
GPS control point.
A full traverse and topographic survey was conducted for stations CC3 through CC122 and CC223 through CC231
(Figure 5). This topographic survey did not include stations CC228 and 230 (which were located on the northeast
side of the stream and included only as necessary points to connect the others), extending approximately 100 feet to
the west of the traverse line and to the limits of visibility east toward the creek. Geographic horizontal coordinates
and elevations for control points referenced above are graphically indexed and tabulated in the Appendix.
Initial terrain analysis was performed using digital elevation models (DEM) from the U. S. Geological Survey (USGS).
These datasets have a spatial horizontal resolution of 30 meters. LIDAR (Light Image Detection and Ranging) data
were later obtained from the municipality of Anchorage with a spatial horizontal resolution of five feet. The LIDAR
dataset agreed very well with field measurements and provides a robust dataset with which to perform pipe routing
and slope analysis. The field points allow for correlation of LIDAR information with actual ground positions and the
topographic survey data allows for further refinement of the terrain for engineering design purposes. Figure 6 shows
an image of the digital terrain model thus derived and applied in this study.
March 2011 8 California Creek Hydroelectric Feasibility
F IGURE 4. GPS CONTROL NETWORK FOR SURVEYS ALONG C ALIFORNIA
C REEK IN 2010.
March 2011 9 California Creek Hydroelectric Feasibility F IGURE 5. L EVEL LOOP AND TRAVERSE LOCATIONS SURVEYS ALONG C ALIFORNIA C REEK FOR 2010. T HE
INSET SHOWS THE PROFILE OF THE LEVEL LOOP . D OTS AND NUMBERS SHOW LOCATIONS OF CONTROL
POINTS PLACED TO SUPPORT THIS AND FUTURE SURVEYS . T HE BLUE LINE IS THE CREEK CHANNEL .
March 2011 10 California Creek Hydroelectric Feasibility
F IGURE 6. I MAGE OF DIGITAL TERRAIN MODEL DERIVED FROM FIELD MEASUREMENTS AND DATA ON
FILE FOR APPLICATION IN THIS ANALYSIS . D OTS LOCATE SELECTED FIELD MEASUREMENTS AND THE
BLUE LINE IS THE CREEK CHANNEL .
March 2011 11 California Creek Hydroelectric Feasibility H y d r o l o g i c a l I n v e s t i g a t i o n s
S t r e a m G a u g e M e a s u r e m e n t s a n d A n a l y s i s
Actual flow data for California Creek is important for estimating seasonal
variations of flow in the catchment basin. A water level-measuring system
was installed in California Creek on April 9, 2010 for this purpose. The
system consists of two HOBO U20 Water Level Loggers (Figure 7),
manufactured by Onset Computer Corporation, deployed in a stilling
well so one is below and the other is above the water level in the creek.
Both sensors record absolute pressure. The sub-aerial unit records
atmospheric pressure to subtract from data recorded by the submerged
sensor to compute hydrostatic pressure and water depth above the sensor.
Both data loggers include temperature sensors, so air and water
temperatures are also recorded.
The sensors are placed inside a pvc pipe stilling well affixed to the bed by
two driven rebar rods and clamped to a log that appears to be in a stable
position across the creek (Figure 8). The location of the gauge is N 60 58 24.2 N, 149 08 25.9 W (see Figures 9
and 10). This location is just below a point at which the valley walls narrow into a gorge, but above a complex of
braided channels near the bridge on Crow Creek Road. The horizontal area of the drainage basin above the gauge site
is approximately 4,000 acres 6.25 square miles.
Figure 7. HOBO U20 water level data
logger (Onset Computer Corp.)
March 2011 12 California Creek Hydroelectric Feasibility
F IGURE 8. S TREAM GAUGE STILLING WELL (PVC PIPE ) ON C ALIFORNIA C REEK , FIXED TO ONE
OF TWO LOGS THAT LIE ACROSS THE CREEK CHANNEL . F LOW AT THIS TIME (A PRIL 9, 2010)
WAS MEASURED AS 5 CUBIC FEET PER SECOND , WHICH IS THE ASSUMED HABITAT MINIMUM
FLOW ABOVE WHICH FLOW CAN BE DIVERTED FOR POWER GENERATION .
March 2011 13 California Creek Hydroelectric Feasibility F IGURE 9. L OCATION OF STREAM GAUGE AND C ALIFORNIA C REEK WATERSHED BOUNDARIES
A series of current measurements were made at the time of deployment, in conjunction with measuring a cross-
section of the flow. These data are displayed in Table 1 and Figure 11. Offset data are horizontal distances from a
reference nail in the lower log. Current speed 2 ft left (looking downstream) of the reference (offset = -2 ft) was
affected by a rock just upstream. The total flow at the time of the measurements, approximately 1500 on 9 April
2010) was 5.1 ft3/sec.
Table 1. Flow cross section and current measurements and flow computations;
California Creek stream gauge April 9, 2010
offset
(ft)
depth
(ft)
current
(ft/sec)
section
number
section
boundary
depth at
boundary
section
area (ft
2)
current
(ft/sec)
flow
(ft3/sec)
3 0 0 1 2.5 0.225 0.2 0 0.0
2 0.45 0 2 1.5 0.525 0.5 0 0.0
1 0.6 1.46 3 0.75 0.7 0.5 1.5 0.7
0.5 0.8 3.1 4 0.25 0.775 0.4 3.1 1.2
0 0.75 3.38 5 0.65 0.675 0.6 3.4 2.1
1.3 0.6 1.46 6 1.8 0.65 0.8 1.5 1.1
2.3 0.7 0.15 7 2.45 0.35 0.4 0.2 0.1
2.6 0 0 8 0.1 0 0.0
March 2011 14 California Creek Hydroelectric Feasibility F IGURE 10. S TREAM GAUGE LOCATION WITH REFERENCE TO USGS TOPOGRAPHIC MAP FEATURES
F IGURE 11. C ALIFORNIA C REEK C ROSS -S ECTION F LOW MEASUREMENTS - A PRIL 9, 2010
A more complete cross-section of the stream generally perpendicular to the flow was measured on June 5, 2010,
when the snow had melted and ground elevations could be measured with more care (Figure 12). Elevations are
relative to a local reference. No additional current speed measurements were made at that time, so the information of
April 9, 2010 was extrapolated to derive the stage-discharge relationship of Figure 13. Stage (water surface elevation)
0
0.5
1
1.5
2
2.5
3
3.5
4
-1
-0.8
-0.6
-0.4
-0.2
0
-3 -2 -1 0 1 2 3 current speed (cfs)Depth (ft)Offset from blue nail on log (ft)
Cross-section of Flow Measurements
data point section boundary current speed
March 2011 15 California Creek Hydroelectric Feasibility data from the gauge was then applied to derive the stage and discharge time series of Figure 14 for the period from
April 9, 2010 to August 20, 2010. The stage-discharge estimates extend only within the comparatively rectangular
lower portion of the stream cross-section at the gauge site where flow will tend to vary linearly with stage. The
emphasis in this study is on low flows that constrain power generation potential.
F IGURE 12. E LEVATIONS ACROSS C ALIFORNIA C REEK AT STREAM GAUGE SITE - J UNE 5, 2010
F IGURE 13. FLOW AREA AND ESTIMATED DISCHARGE VS DEPTH AT C ALIFORNIA C REEK GAUGE
94
95
96
97
98
99
100
101
102
103
104
-60 -55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60Vertical elevation (local reference, ft)Offset from arbitrary center point of cross-section (ft)
Elevations across California Creek at Stream Gauge Site
ground elevation
gauge location +1.7 ft
6/5/10 water surface 96.1 ft
0
5
10
15
20
25
30
35
40
0.0
10.0
20.0
30.0
40.0
50.0
60.0
0 0.5 1 1.5 2 2.5 3 3.5 Flow Area (ft2)Discharge at gauge site (cfs)Depth above gauge (ft)
Flow Area and Discharge vs Depth
discharge vs depth
Flow Area vs Depth
Poly. (discharge vs depth)
best -fit equation adjusted so
hg = 0.70 ft at Q = 5.1 cfs,
as measured 4/9/10
3.4193.127013.1 2
gghhQ
March 2011 16 California Creek Hydroelectric Feasibility
F IGURE 14. C ALIFORNIA C REEK S TAGE AND D ISCHARGE T IME S ERIES , A PRIL 9, 2010 TO A UGUST 20,
2010
0.00
0.50
1.00
1.50
2.00
2.50
3.00
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
Stage (gauge depth, ft)Discharge (cfs)Date and Time
Discharge hydrograph
Stage time series
March 2011 17 California Creek Hydroelectric Feasibility S e a s o n a l S t r e a m F l o w E s t i m a t e
A multi-year time series is available from USGS measurements on Glacier Creek from August 1, 1965 to September
30, 1978, which is plotted in Figure 15. The data is presented in terms of daily averages for each day of the year for
the period of record along with the minimum and maximum measured on each day during the period of record.
California Creek is a tributary of Glacier Creek. This more direct reference to stream flow patterns in Girdwood
Valley is used in lieu of flow estimates derived from precipitation data in this analysis.
F IGURE 15. G LACIER C REEK USGS G AUGE N O . 15272550 D ATA : A UGUST 1, 1965 TO S EPTEMBER 30,
1978.
Glass and Brabets (1987) report peak discharge of 600 cfs in California Creek at its junction with Glacier Creek,
estimated as a rare event of 20-year return period (see Figure 16). The data on which this estimate is based was not
available during this investigation. The site of these USGS measurements was apparently well downstream of
measurements made during this study. A flow of 600 cfs would certainly be a dramatic event substantially above the
banks of the normal creek channel at the present stream gauge site (see Figure 12). Focus of this study is not flood
protection, but hydroelectric power generation potential, in particular the constraints on generation of low flow.
Extreme flood conditions are of interest in power house and transmission line design, however. Further study is
necessary to define high flow frequencies with greater accuracy.
0
1000
2000
3000
4000
5000
0 50 100 150 200 250 300 350Discharge (cfs)Julian Day
maximum
mean
minimum
March 2011 18 California Creek Hydroelectric Feasibility
F IGURE 16. F LOOD FREQUENCY FOR C ALIFORNIA CREEK ESTIMATED BY G LASS AND B RABETS (1987)
Comparison with Glacier Creek flows indicates California Creek is more strongly affected by spring snow melt than
by subsequent storm water runoff during the time of stream gauge deployment for this study. Glacier Creek
experienced maximum flows in September and October due to rain storms, rather snow melt. Average annual daily
mean flows on Glacier Creek occurred in mid-summer, which probably is driven primarily by snowmelt. The
perched valley geometry of California Creek may contribute to its apparent trend toward peak runoff from snowmelt
and lesser response to storm water runoff.
A mean annual hydrograph was estimated for California Creek, as shown in Figure 17, for the purpose of assessing
power generation potential. The mean annual hydrograph of Figure 17 was transformed to a discharge-frequency
curve of Figure 18. The flow of early April (5 cfs) is assumed as the minimum flow for fisheries in the creek below
the waterfalls that are found upstream of the gauge. The assumed fisheries minimum is an estimate that requires
confirmation by fisheries specialists when future refinements to this analysis occur.
March 2011 19 California Creek Hydroelectric Feasibility
F IGURE 17. DERIVED MEAN ANNUAL HYDROGRAPH FOR C ALIFORNIA CREEK . A N ESTIMATED
F ISHERIES MINIMUM FLOW OF 5 CFS IS EXCEEDED M AY TO NOVEMBER ACCORDING TO THIS ASSUMED
ANNUAL FLOW .
Lower flows probably occur each winter. Glass and Brabets (1987) report that flow in California Creek ceases during
cold winter months. Withdrawals for power generation in this analysis are assumed to involve flows in excess of 5cfs.
This assumed fisheries minimum stream channel flow is exceeded about 55 percent of the time in any year.
F IGURE 18. C ALIFORNIA C REEK E STIMATED A VERAGE A NNUAL F LOW F REQUENCY
0
10
20
30
40
0 50 100 150 200 250 300 350Discharge (cfs)Julian Day
0
5
10
15
20
25
30
35
0 20 40 60 80 100Discharge at gauge (cfs)Percent Exceedance
California Creek - Flow Frequency
from derived mean annual hydrograph
March 2011 20 California Creek Hydroelectric Feasibility S u r f i c i a l G e o l o g y
Glass and Brabets (1987) reported that Girdwood valley, in general, is lined with unconsolidated glacial and alluvial
deposits to over 300 ft thick over bedrock. Deposits in the steep California Creek valley are comparatively shallow
and bedrock is much exposed along the creek channel.
The valley of California Creek is reported by Glass and Brabets (1987) as having gravel and sand with minor amounts
of silt over bedrock in the fan-shaped terrace immediately above its junction with Glacier Creek. The canyon above is
dominated by exposed metamorphic bedrock of marine origin with intermittent glacial moraine deposits of boulders
and gravel. A terrace that follows the canyon to the west has gravel and sand of glacial or alluvial origin. This terrace
includes the route of the hiking trail up the valley that is steep, consistently of 10% or greater grade. The terrace is
densely overgrown with rain forest vegetation typical of the Girdwood valley floor. The edge of the terrace at the
canyon is precipitous, making access on foot dangerous.
Valley slopes on the east side and above the terrace to the west have a complex mix of sand, gravel, and boulders
affected by landslides, snow avalanches, and runoff channels among buttresses of exposed bedrock. These slopes are
also heavily overgrown with rain forest vegetation. Mountain slopes above the California Creek valley are dominated
by exposed bedrock.
The region surrounding Girdwood may have experienced subsidence up to 5 ft (1.5 m) during the 1964 Great Alaska
Earthquake. The town of Girdwood was subsequently moved inland due to subsidence of its former location nearer
Turnagain Arm. Local subsidence of unconsolidated sediments to 3 ft (0.9 m) is estimated by Shennan et al (2004).
All of south-central Alaska, including Girdwood valley, is in seismic zone 4 with regard to building code
requirements. This is the zone of highest risk for earthquake-induced building damage.
March 2011 21 California Creek Hydroelectric Feasibility P r o s p e c t i v e I n t a k e S i t e s a n d P e n s t o c k R o u t e s
The place at which water is withdrawn from the natural channel is important to the mechanical efficiency of the
hydroelectric system and critical for minimizing impacts of the system on the creek and creek side environments. The
site must accommodate selective withdrawal of water into a penstock pipe that can be routed downhill to the
powerhouse with minimum expense and disruption of the natural setting along the penstock route. A means of flow
control is necessary to operate the system such that the fisheries minimum flow, assumed in this case to be 5 cfs, is
continuously free to flow down the natural channel, while some or all flow in excess of that amount is diverted. The
intake configuration should include a mechanism to prevent flotsam and sediment from flowing down the penstock
and into the turbine. Small hydropower systems most often employ metal grating, called a trash rack, to exclude
flotsam. If anadromous or important resident fish are present, a finer screen may be required. Many designs involve
structures to reduce water velocities so most sediment
settles before clean water flows into the penstock.
Sand and gravel are dangerous to hydraulic turbines
and cause wear to the penstock pipe and to any valves
and joints in the pipe system.
Perhaps the most conventional approach to
controlling flow is to construct a dam or weir to form
a pool in which sediment settles before water is
withdrawn. Dams of wood, steel, concrete or a
variety of synthetic materials can be built with
spillways for flow to bypass the withdrawal system
and a trashrack-covered intake structure built into or
beside the dam. A weir is essentially a dam with a low
spillway elevation such that water continuously flows
over the crest of the weir for much or all of its length.
An alternative to a dam or weir across the stream
channel is to build a diversion canal that protrudes
into the natural channel such that some flow enters
the canal whose features allow sediment to settle
before water flows through a trashrack-covered
penstock intake.
California Creek is a cascading mountain stream
flowing down a canyon for much of its length.
Numerous waterfalls are connected by steep, fast-
flowing boulder-strewn rapids (see Figure 19).
Further study will be required to confirm that one or
more of these waterfalls preclude upstream migration
of important resident or anadromous fish, but this
appears likely to be the case.
Withdrawal from the canyon will be necessary to achieve a worthy efficiency for hydroelectric power generation.
Two sites have been selected that would accommodate penstock routing along the valley slope. The lower site is
within HLB land and the upper site is beyond the HLB boundary, inside Chugach State Park.
F IGURE 19. U PPER S ITE PROPOSED FOR DIVERSION
OF FLOW BETWEEN TWO WATERFALLS IN THE
C HUGACH S TATE PARK PORTION OF THE
C ALIFORNIA C REEK CHANNEL
March 2011 22 California Creek Hydroelectric Feasibility P r o p o s e d u p p e r s i t e i n t a k e a n d p e n s t o c k d e s i g n
The proposed upper intake site is between two waterfalls shown in the photograph of Figure 19. Figure 20 maps the
location of both proposed intake sites and penstock pipe route. The drainage area above the proposed upper intake
site is approximately 3,500 acres or 5.5 square miles.
F IGURE 20. P ROPOSED ALTERNATIVE ROUTES FOR PENSTOCK PIPE FROM INTAKE TO POWERHOUSE .
I NSET SHOWS RELATION OF PROPOSED PIPE ALIGNMENT WITH EXISTING TRAIL .
March 2011 23 California Creek Hydroelectric Feasibility The falls below the proposed lower intake site and other steep rapids and falls downstream are assumed to preclude
upstream migration of important resident and anadromous fish, particularly salmon, therefore salmon spawning and
downstream migration of salmonids or other fish species in the pool between these falls is assumed not to occur.
Measures to exclude fish from the intake, such as used for roadside withdrawals for road construction and
maintenance in lower, flatter terrain (e.g., McLean 1998) are likely to be unnecessary at this site. These assumptions
must be verified to the satisfaction of the Alaska Department of Fish and Game and/or the US Fish and Wildlife
Service, and National Marine Fisheries Service as part of the environmental analysis process. Means to exclude
sediment and branches or other flotsam will be required to protect the penstock and turbine.
The withdrawal system design favored for the upper site is to enhance the crest of the lower water fall with natural
boulders moved from the surrounding terrain to create a pool above about 3 to 4 feet deep during ordinary summer
flow conditions. Some boulders may possibly be extracted from the pool area. This modification by itself would
appear natural and would even enhance the vertical drop of the lower waterfall. Wire-mesh gabions filled with rocks
from the surrounding terrain may be necessary to enhance stability of the weir structure, but could conceivably be
placed so as to be underwater and difficult to see.
D r o p I n l e t . Rock-filled wire mesh gabions would also accommodate placement of pipe through the weir to lie at
the bottom of the pool where it would connect to a prefabricated trashrack-covered drop inlet. Figures 21 and 22 are
F IGURE 21. I NTAKE CONFIGURATION PROPOSED FOR FURTHER STUDY AT THE UPPER SITE .
March 2011 24 California Creek Hydroelectric Feasibility F IGURE 22. P REFABRICATED CONCRETE DROP INLET
CONCEPT . A MANUALLY OPERATED VALVE AND AN AIR
VENT WILL BE CONNECTED IMMEDIATELY
DOWNSTREAM OF THE INTAKE STRUCTURE .
conceptual schematics of the design. The pool in which the inlet is placed would reduce turbulence to allow
settlement of sand and gravel so clean water enters the penstock. A trashrack would prevent flotsam carried into the
intake from entering the penstock. Horizontal orientation of the trashrack, and, if necessary fish-excluding screen,
would make cleaning of the trashrack comparatively simple and safe. Major blockage by flotsam would have a
tendency to be washed downstream by its own induced backwater, since the crest of the inlet cylinder will not, by
design, extend above the pool elevation. Preliminary computations indicate a 4-ft diameter cylinder only 2 to 2.5 ft
high would accommodate the expected range of inflow (0 to 25 cfs) with head (water level) of only 1 ft higher than
the edge of the cylindrical inlet. Anchoring by drilled and driven rods may be necessary supplement the weight of the
assembly to resist hydraulic and ice forces. Hundreds of farm ponds and larger impoundments around the world use
drop inlets. The prospective advantages of the prefabricated drop inlet design for cascading alpine streams like
California Creek warrant further analytical and laboratory investigations.
P o w e r C a n a l . A more conventional
alternative for an intake design at this location is a
power canal consisting of a concrete flume that
captures a portion of the flow and directs it to a
trashrack-covered penstock intake chamber (Figures
23 and 24). The artificial channel would be
composed of prefabricated sections that can be
lowered by helicopter for placement and
connection at the site. The power canal option
would also require construction of a weir at the
head of the second waterfall to enhance the depth of
the pool above. The steep rocky walls of the canyon
at this location will complicate the placement of the
power canal and the result will be readily visible.
Both designs would be configured to continuously
pass at least 5 cfs over the weir into the natural
channel during all flow conditions.
March 2011 25 California Creek Hydroelectric Feasibility Figure 23. Conceptual profile view of a power canal (diversion channel) at the upper intake site
P e n s t o c k D e s i g n . The pipe and fittings that convey water to the turbine are collectively called the penstock.
Basic features of a micro-hydropower penstock are illustrated in Figure 25. An upper shut-off valve is installed at or
near the intake. A relief pipe immediately downstream prevents formation of a vacuum when the upper valve is
closed, relieves water hammer pressure, and releases air. The relief pipe opening must be higher than the intake
water surface elevation. A lower shut-off valve immediately upstream of the turbine allows flow to be stopped inside
the powerhouse. A drain pipe immediately upstream of this lower valve accommodates penstock drainage for
maintenance or repair. A pressure gauge should be installed between the lower shut-off valve and turbine.
Figure 20 shows a proposed penstock pipe route that would lead the pipe along a bench above the steepest part of the
canyon. The upper intake site and the lower pressure portion of the penstock lie within the Chugach State Park. The
total length of the penstock is approximately 5,100 ft. Preliminary computations indicate an optimum inner pipe
diameter of 14 inches to carry up to 25 cfs with minimum frictional losses through the pipe.
Figure 26 is a plot of the vertical penstock profile along this route that was derived from ground elevations along the
proposed route. The profile includes a gross head (vertical distance to free water surface) of 475 ft from the intake at
elevation 730 ft to the powerhouse at 260 ft elevation. Since the pressure inside the pipe is proportional to the head,
the upper portion of the Penstock may be constructed of high-density polyethylene (HDPE) pipe that is less expensive
March 2011 26 California Creek Hydroelectric Feasibility FIGURE 24. CONCEPTUAL PLAN FOR A POWER CANAL AT THE UPPER INTAKE SITE
and easier to handle during placement in the difficult terrain. Hydrostatic pressures build to about 220 psi at the
lowest point in the profile, which is less than the 267 psi rating the strongest HDPE pipe available. This factor of
safety is not acceptable and a factor of at least 2 provides an acceptable margin. A pressure with a factor of safety of 2
occurs at about elevation 480 ft along the profile, in the steepest reach of the penstock alignment. The final 900 ft of
penstock is proposed to be built with welded zinc-coated steel pipe conforming to ASTM A53-1993 specifications,
which is rated at 640 psi, assuring a hydrostatic pressure factor of safety greater than 2 all along the pipe. By building
the upper 4,200 ft of the 5,100-ft penstock with HDPE pipe, difficulties with placement and anchoring in the rugged
terrain are minimized. This in turn will minimize the physical disturbance of the natural terrain and vegetation during
construction. Water hammer from sudden shut of the flow could cause pipe pressure ratings to be exceeded, but
slow closer of the lower valve (taking 20 seconds or more) will prevent this.
March 2011 27 California Creek Hydroelectric Feasibility
F IGURE 25. S CHEMATIC DIAGRAM OF TYPICAL COMPONENTS OF A HIGH -HEAD LOW -FLOW MICRO-
HYDROPOWER SYSTEM
March 2011 28 California Creek Hydroelectric Feasibility
Table 2 provides survey coordinates for the alternative intakes, powerhouse, and stream gauge locations investigated
in this study.
Table 2. Coordinates of Alternative Intake, Powerhouse, and Stream Gauge Sites
Site
X coordinate (ft) Y coordinate (ft) Z coordinate (ft)
Proposed Upper Intake Site 1791550 2552950 740
Proposed Lower Intake Site 1792450 2550930 590
Proposed Powerhouse Site 1793020 2548540 260
Stream Gauge Site 1793150 2548550 240
Horizontal Datum: NAD83 State Plane Alaska Zone 4 (Feet); Horizontal Accuracy: < 30 feet
Vertical Datum: NAVD88 (Feet); Vertical Accuracy: <5 Feet
F IGURE 26. P ROFILE PROPOSED FOR THE PENSTOCK ROUTE FROM THE UPPER INTAKE SITE TO
THE POWERHOUSE
March 2011 29 California Creek Hydroelectric Feasibility P r o p o s e d l o w e r s i t e i n t a k e a n d p e n s t o c k d e s i g n
Intake design options for the lower intake site are essentially equivalent to those at the upper site, except that the
lower site is a setting of cascading rapids rather than a natural pool between 2 waterfalls. A boulder weir, reinforced
with rock-filled wire-mesh gabions on the upstream side, will be necessary to create a pool with depth sufficient for
diversion of flow in excess of the assumed 5 cfs fisheries minimum. As with the upper site, the drop inlet options will
involve less disruption of the natural setting and is the recommended choice.
Figure 27 shows the creek characteristics at the proposed lower intake site, just within the boundary of Heritage Land
Bank (Municipality of Anchorage) property, as indicated in Figure 20. The area of the drainage basin above the
proposed lower intake site is approximately 3,800 acres or about 6 square miles.
Figure 28 shows the approximate profile of the proposed penstock along the route of Figure 20. This alternative has a
gross head of 325 ft along a penstock of 3,050 ft in length. In this case, the lower steep reach of 175 ft length and the
last level 150 ft of penstock before the powerhouse should be constructed of steel pipe. The upper 2,725 ft of the
penstock can be constructed of lighter-weight less expensive HDPE DR 7 pipe.
Yanity (2007) discusses a potential head for hydropower on California Creek of about 390 ft (120 m). The context of
that report implies that this is the maximum head available within the property owned by Heritage Land Bank (HLB),
rather than selection of a specific site. That study did not apparently involve topographic measurements. The
reported prospective head does falls between those of the two sites proposed, one within and one beyond the HLB
boundary.
Both alternate sites proposed herein will be accessible by improvement of the trail to be passable by small all-terrain
4-wheeler vehicles carrying hand-operated tools. Heavier materials can be slung into place near their final
deployment with minor clearing of drop sites. The trail can be restored to the appearance of a foot path and clearing
allowed to grow over, such that disruption of the rain forest scenery and mountain vistas clearing is not degraded.
The higher site provides substantially greater head and power generation potential from between two natural falls,
without loss and possibly visual enhancement of the ambient scenery. The lower site lies below the HLB boundary
and does not impact scenery or flow in the creek within Chugach National Forest.
March 2011 30 California Creek Hydroelectric Feasibility F IGURE 27. P ROPOSED ALTERNATIVE INTAKE SITE JUST BELOW THE BOUNDARY BETWEEN
HERITAGE L AND B ANK P ROPERTY AND C HUGACH S TATE P ARK
F IGURE 28. P ROFILE OF PENSTOCK ROUTE FROM LOWER ALTERNATIVE INTAKE SITE
March 2011 31 California Creek Hydroelectric Feasibility E l e c t r o -M e c h a n i c a l C o n c e p t u a l D e s i g n
T u r b i n e s : l i t e r a t u r e r e v i e w a n d s e l e c t i o n m e t h o d o l o g y
In the beginning of this assessment study, a literature review was conducted to collect published material on different
types of turbines and their suitability to the design criteria at the California creek. The information collected is
summarized below.
Turbines are divided into two main classes: (1) impulse or velocity turbines and (2) reaction or pressure turbines. An
impulse turbine changes the velocity of the jet of water. A smaller velocity of water leaving the runner means that a
higher kinetic energy of the jet has been converted to mechanical energy. With this turbine, the water jet is created
by a nozzle aimed at the runner wheel. The jet impinges on the turbine blades, the runner absorbs the resulting force
and the momentum of the jet is changed. Impulse turbines are suitable for high head applications and a small-sized
impulse water turbine does not require high volumetric flow. Impulse turbines are well-suited for steep sites with
relatively small flow rates, such California Creek.
In a reaction turbine, the conversion of energy occurs in an enclosure with hydraulic pressure greater than
atmospheric. Hydraulic pressure causes the turbines rotor to move. Reaction turbines are generally used for low-
head high-flow applications. Table 3 below shows different types of impulse or reaction turbines that can be used for
small-scale hydroelectric projects. Other types of turbines include Bulb, Tube, Straflo, Tyson, Gorlov, Water
Wheel, and Archimedean Screw.
Table 3. Groups of Impulse and Reaction Turbines
Turbine runner Head (pressure)
High Medium Low
Impulse Pelton Crossflow (Mitchell/Banki) Crossflow (Mitchell/Banki)
Turgo Turgo
Multi-jet Pelton Multi-jet Pelton
Reaction Francis Propeller
Pump-as-turbine (PAT) Kaplan
Source: Inverson 1986
The approximate turbine output power can be calculated as follows:
, where
P = Output power of the turbine in kW, Q = flow (m3/sec), H = head (m), e = combined efficiency of the turbine
and generator. For this project, Q and H were determined using the hydrology data collected. Theoretically, e is
calculated as:
Turbine efficiencies can range from 25% - 90%, with higher efficiency at higher heads, depending on the type of
turbine used (Solar Taos Product Catalog 2010). Overall efficiencies of 80 to 85 percent are typical.
e OutputPower
InputPower
March 2011 32 California Creek Hydroelectric Feasibility Specific data about the site needed to select a turbine design include the head (vertical drop of the water), the
volumetric flow rate of water, and the length of the penstock (pipe) through which the water flows from the intake to
the turbine (powerhouse). A larger flow means more power that can potentially be generated. Impulse turbine nozzle
numbers and sizes can vary with the flow rates and stream conditions during different times of the year. Turbines are
important in that they determine the efficiency of the system. There were several criteria used to select a turbine for
this project: the net head, the flow rate through the turbine, the rotational speed of the turbine, and the cost.
H e a d
The hydraulic head is an important aspect of the turbine selection process, as it measures the ratio of the hydraulic
energy of machine by the acceleration due to gravity. Table 4 indicates the typical ranges of head for each type of
turbine. Yanity (2007) gathered data for California Creek, estimated a net head of 120 meters (394 ft). Based on that
estimate, there are three types of turbines that can be considered at this head: the Pelton wheel, and the Turgo and
Crossflow turbines.
Table 4. Ranges of Hydraulic Head Suitable for Various Types of Turbines
Turbine Range of Head m (ft)
Hydraulic wheel turbine 0.2 (1) < H < 4 (13)
Archimedes' screw turbine 1 (3) < H < 10 (33)
Kaplan 2 (7) < H < 40 (130)
Francis 10 (33) < H < 350 (1150)
Pelton wheel 50 (164) < H < 1300 (4300)
Turgo 50 (160) < H < 250 (820)
Crossflow 5 (16) < H < 200 (660)
F l o w r a t e
In April 2010, when the snow pack feeding the creek starts to melt, the flow measured in California Creek was just
above 5 cubic feet per second (cfs). This flow rate reached as high as 30 cfs for some weeks in May 2010 before
gradually decreasing again throughout the remaining summer months. The flow decreased to about 15 cfs by mid-
July, and further decreased to about 10 cfs in August. The estimated average annual flow at the stream gauge site is
presented in Figures 16 and 17. A minimum flow of 5 cfs is being use for all calculations based on estimated fisheries
habitat needs. Figures 29 and 30 are used to determine the type of turbine that can be used based on the design flow
and net head. Using this criterion, the choice of turbine is narrowed to two choices: Pelton wheel or Turgo wheel.
March 2011 33 California Creek Hydroelectric Feasibility
F IGURE 29. T URBINE SELECTION CHART BASED ON FLOW RATE VS . AVAILABLE HEAD (WWW .
HYDROPOWERSTATION .COM )
F IGURE 30. T URBINE SELECTION CHART BASED ON NET AVAILABLE HEAD V S . DISCHARGE (WWW .
HYDROPOWERSTATION .COM )
March 2011 34 California Creek Hydroelectric Feasibility R o t a t i o n a l s p e e d o f t h e t u r b i n e
Different types of turbines are used for different heads, as mentioned earlier,. This is because the closer the shaft
speed is to 1500 rpm, the smaller is the speed change required between the turbine and the generator. In general,
the speed of a turbine declines in proportion to the square-root of the head, which is why low-head sites require
typically faster turbines. The Turgo wheel typically has a higher rotational speed than the Pelton wheel for the same
flow and head, but is also lower in efficiency.
C o s t o f t h e t u r b i n e
The Turgo turbine is similar to the wheel turbine only that its buckets are shaped differently and the jet of water hits
the plane of the runner at an angle of 20 degrees, compared to the 180 degrees from the Pelton wheel. Compared
with Pelton wheel, the Turgo costs more. For instance, a Pelton wheel costs between $900 - $1, 400, depending on
the number of nozzles required. A Turgo turbine, on the other hand, costs somewhere between $1, 695 - $1, 845.
From the previous criterion, it appears both turbine types can function equally well with the parameters of California
Creek, and therefore, the inexpensive option is chosen, which is the Pelton wheel and the cost of that turbine is
$352,225 (Appendix A-5).
P e l t o n W h e e l
A Pelton wheel turbine is the most common type of impulse turbine used for high-head, low-flow micro-hydro
projects (Figure 31). A water jet strikes the blades of the runner, known as buckets. This impulse energy spins the
runner, which is connected to an electrical generator. Figure 32 shows components of a typical micro-hydro system
that incorporates a Pelton wheel (see also Figure 25 above).
F IGURE 31. SCHEMATIC OF THE CROSS -SECTION OF A P ELTON WHEEL (WWW .ENERGYSAVERS .GOV ).
March 2011 35 California Creek Hydroelectric Feasibility
F IGURE 32. T YPICAL MICRO -HYDRO INSTALLATION SCHEMATIC (WWW .LIGHTMYPUMP .COM ).
Calculating power generated
The following presents a mathematical analysis involved in determining the power generated. The general equation
for fluid flow between two points is represented by the Bernoulli equation. Assuming that Point 1 is located
upstream, while Point 2 is at the nozzle, the energy equation of the system is presented in Equation 1.
1 1
2
2 1
2 2
2
2 2
2
21
1
Where
P = Pressure = Specific weight D = diameter
V = Velocity f = Friction factor fT = Fully rough friction factor
z = Elevation L = Pipe length K = Minor loss
C = Minor loss N = Number of pipe segments
Because Point 1 is located at the free surface upstream, it can be assumed that V1 = 0, and V2 is defined as
the velocity of the jet of water that comes out of the nozzle. P1 and P2 are atmospheric pressure, i.e., zero
gauge pressure, hence, those terms will drop from the equation. The flow rate Q is related to the velocity
of the water, V, and the cross-sectional area of the pipe, A. This relationship is presented in the following
equation.
March 2011 36 California Creek Hydroelectric Feasibility 4
2 4
2 2
To determine the friction factors, several equations can be used. First, the Reynolds number has to be
calculated using Equation 3.
3
where is the density of the water and its dynamic viscosity.
The friction factor f can be determined by one of the following equations, depending on the type of flow.
64 2100 4
Up until this point, all the values are known such as the water density and dynamic viscosity. Other values
like the flow rate and the pipe diameter are measured, while the rest, like the Reynolds number, are
derived from known fluids equations.
For the non-laminar (turbulent) range, an iterative algorithm (equation 5) is utilized to determine the
friction factor, f. In this equation, is the surface roughness of the inside of the pipe, and its value can be
found from vendors literature or in fluid mechanics texts. Minor losses K and C (in Eq. 1) can also be
found in the literature.
1 2 log 3 7
2 51 5
After all the parameters are defined, Equation 1 can be rewritten in order to obtain the velocity of the jet at
the nozzle. This velocity is important because it is the velocity that strikes the bucket and causes the turbine
to spin and produce power.
2 2 1 2
8 2
2 2
1
6
For Pelton turbine power output is at the maximum when the speed of the wheel is half the jet velocity.
The maximum turbine power (in watts) would be represented using the Equation 7.
2
4
4 1 7
March 2011 37
where is the the angle of the exit edge of the blade. This can be shown in the Figure 33 below.1 Ideally,
this is 180 degrees, but physical constraints restrict it to be less than 180 degrees.
F IGURE 33. R ELATIVE VELOCITIES OF THE JET ON THE P ELTON W HEEL BUCKET .
Using calculus, an optimum nozzle diameter D can be obtained using Equations 6 and 7. The general idea is
that the expression for V2 in Equation 6 is substituted into Equation 7. This way, Pmax would be expressed as
a function of D. The value of D that maximizes power would be the D that satisfies the condition that:
The iterative process of determining nozzle diameter is not pursued in this study due to the fact that the
turbine manufacturers already optimize this parameter in their design and a customized turbine design is not
sought here.
The total power generated would be less than Pmax due to the efficiency of the generator and the load
factor. If is the efficiency of the generator, the total power generated by the system would be:
Figures 34-37 illustrate the results of these computations applying the parameters established for California Creek,
with reference to the derived average annual flow (Figure 16). Figures 34 and 35 estimate the power produced from
the upper intake site. Figures 36 and 37 estimate the power produced from the lower intake alternative. Figures 34
and 36 present power production in terms of the calendar year. Figures 35 and 37 show the power produced in terms
of the amount of time for varying levels of production during an average year, in a manner similar to Figure 16 above.
March 2011 38 California Creek Hydroelectric Feasibility In the following two illustrations for the upper intake structure, pipe sizes of 13, 14 and 15 inches are shown. The
two vertical lines show when California Creek is expected to have at least 5 cfs of flow (765 gross head).
F IGURE 34. U PPER I NTAKE S TRUCTURE : ESTIMATED ANNUAL OUTPUT OF 489,114 KWH WITH 5 CFS
WATER FLOW MINIMUM OBSERVED
March 2011 39 California Creek Hydroelectric Feasibility
F IGURE 35. U PPER I NTAKE S TRUCTURE : THE VERTICAL LINE AT ~55% IS WHERE THE FLOW RATE IS AT
5 CFS (WITH THREE DIFFERENT PIPE SIZES SHOWN , 475 FT GROSS HEAD )
March 2011 40 California Creek Hydroelectric Feasibility In the following two illustrations for the lower intake structure, pipe sizes of 13, 14 and 15 inches are shown. The
two vertical lines show when California Creek is expected to have at least 5 cfs of flow (765 gross head).
F IGURE 36. L OWER I NTAKE S TRUCTURE : ESTIMATED ANNUAL OUTPUT OF 309,600 KWH WITH 5 CFS
WATER FLOW MINIMUM OBSERVED
March 2011 41 California Creek Hydroelectric Feasibility
F IGURE 37. L OWER INTAKE STRUCTURE : THE VERTICAL LINE AT ~55% IS WHERE THE FLOW RATE IS AT
5 CFS (WITH THREE DIFFERENT PIPE SIZES AND 325 FT GROSS HEAD )
March 2011 42 California Creek Hydroelectric Feasibility P r e l i m i n a r y E l e c t r i c i t y C o s t A n a l y s i s
Based on the power calculations above, the maximum capacity of the electro-mechanical equipment would be about
192 kW (see Appendices, page A-3). A generating efficiency of 82% is applied, decreasing this value to 158 kW. The
annual electricity generated can be estimated as:
Annual Electricity Generated = 101.898 kW * 4800 = 489114 kW-hr per year
This calculation is made using a gross head of 475 ft (144.8 m) and a minimum flow rate of 5 cubic feet per second,
which is a flow rate encountered in the months of April and May. This flow rate increases to around 30 cfs maximum
over the summer months, however, the generator capacity is capped at 158 kW (The corresponding daily average
power output is shown in Figures 34-37 above).
A price quote obtained from Canyon Hydro indicates that the price of electro-mechanical equipment would be
around $278,300; a smaller turbine is selected for 325 feet gross head for a flow rate of 5cfs (see Appendix). This
includes the turbine, the generator and the switchgear/controls. This is the largest single capital cost of the system.
Costs for the materials and placement of the intake and penstock are not included, nor are costs for a powerhouse
enclosure or tailrace structure to return flow to the natural stream. Turbines normally serve 25 years without
replacement of major components, if well maintained and operated with care. A 5% interest rate is assumed based on
30-year fixed rates specified by some private lenders as of August 2010. Therefore, if the turbine cost were to be paid
over 25 years, the annual payment can be calculated using the following equation.
, where
PV = Present Value, n = number of periods, and i = Interest rate.
An annual payment of $19,552 will be required over the next 25 years in order to pay off the cost of the turbine. If
the consumer was to pay for this value, the cost of electricity just to recover the turbine cost would be 4 cents per
kilowatt-hour. This was obtained using the following calculation:
$/kWh = Annual Payment for Capital Cost/ Annual Electricity Demand = $19,552 /489114 kWh = 0.04
Aside from the turbine and other capital costs, operations and maintenance (O & M) costs have to be considered as
well. According to the Wind Energy The Facts website (http://www.wind-energy-the-facts.org/), these costs can
include a variety of expenses such as insurance, regular maintenance, repair or part replacement, and administration,
and can easily be 10-15% of the capital cost over its lifetime. However, Eric Mandel, a representative of Canyon
Hydro, indicated that 5% of the capital cost is a conservative estimate for O & M cost. Assuming the O & M for this
project would be about $13,915 per year, the cost of electricity required to pay for the cost of O & M would be 2.84
cents per kilowatt-hour:
$/kWh = Annual Payment for O & M/ Annual Electricity Demand = $13,915 /489114 kWh = 0.0284
Based on these calculations, the cost of electricity to recover the above capital and O & M costs would be $0.06845
per kilowatt-hour.
Chugach Electric provides a 60 cycle AC, which can be single or three phase at available standard voltages. There is
no difference in charges for peak load or otherwise. The current rate from Chugach Electric is $0.118872 per kWh.
PMT =
i * PV
1 -(1 + i)
-n
March 2011 43 California Creek Hydroelectric Feasibility As can be seen, there is a price difference of $0.05 per kWh. The turbine and operations and maintenance costs
would be recovered in 7 to 8 years (see Appendix). If the time to recover all costs is double (14 years), the project
will be paid for well within its service life. Larger hydroelectric projects involving major construction of dams and
large outlet works may take 20 to 30 years to recover their initial costs. By extending the recovery time, reduced
prices can be offered to consumers using the system. Though more detailed analysis of construction costs, operations
and maintenance costs, and power pricing is necessary, the project appears to be economically feasible and more
detailed investigation appears to be a worthy investment for the sake of future residents in the vicinity of California
Creek.
Chugach Electric has a stated policy of paying no more than the utilitys avoided cost of generation for power
provided from alternate energy sources, that is, the cost of producing power in its own gas-powered plants. This
avoided rate, as it is called in literature, is much less than the price Chugach Electric customers pay for power
provided by the utility. Elsewhere in the US and abroad utility companies sometimes pay the same rate as they charge
customers. This practice is generally known as net metering. The Chugach Electric policy is in compliance with the
Public Utility Regulatory Policies Act (PURPA) of 1978, which requires utility companies to buy power back from
qualifying facilities at least at an avoided rate.
A change to net metering would make a significant difference toward economic feasibility of small renewable power
systems in the Chugach Electric service region. This change, at a minimum, would require action by Chugach Electric
customers. It may require legislative change as well.
The residential developments planned in the immediate vicinity of California Creek will certainly need power year-
around and must therefore be connected to the power grid of Chugach Electric Association. Negotiations with
Chugach for these arrangements are certain to be necessary regarding what consumers will be charged. The price of
natural gas will increase and the cost of power generated from burning natural gas will follow. Incentives to reduce
dependence on fossil fuels are currently receiving serious attention in the US and around the world. These issues will
have to be addressed in Alaska, if renewable energy at a neighborhood scale is to succeed and dependence on burning
expensive fossil fuels and attendant harmful impacts on climate is to be mitigated.
March 2011 44 California Creek Hydroelectric Feasibility P r e l i m i n a r y E n v i r o n m e n t a l R e v i e w
This environmental review is a high altitude look at what is likely to be required for an environmental analysis and
permitting prior to beginning final design and construction. The following is based in part on an academic report
completed by Grant Lidren while enrolled as a student in AEST A607 Environmental Permitting Project, a course in
the Applied Environmental Science and Technology graduate program at the University of Alaska Anchorage. Mr.
Lidrens report was augmented by Alaska Green Energy following review of the Engineering portion of this report.
The assignment completed by Mr. Lidren was independent of the engineering analysis contained in this report.
The proposed impacts of the micro-hydroelectric facility will need to be taken into consideration for permitting
purposes. For example, the alteration of stream flow, evident by a discharge from the penstock and the location of a
powerhouse will likely require the removal of vegetation which could affect the riparian microclimate of the stream.
Because at least the lower portion of California Creek is an anadromous stream, authorization will likely be needed
from the Alaska Department of Fish and Game, and a water appropriation received from the Alaska Department of
Natural Resources. Review by the US Fish and Wildlife Service, National Marine Fisheries Service will also have
interests in placing mandatory conditioning license clauses or permit requirements for developments because at least
a portion of California Creek is an anadromous stream. The US Army Corp of Engineers generally requires a Section
404 permit for discharging dredge of fill materials into U.S. waters; which is likely going to be required for intake
structure construction. Lastly, depending on the final location that is selected, removal of traditional berry picking,
other uses and aesthetic changes could affect the social aspects of this environment (RCA, 2007).
Further baseline environmental analysis and data will need to be collected before the project can be permitted and/or
constructed. This baseline data will be used to record if any significant impacts are expected to occur from the
project and to also determine what permits or authorizations will be needed. Another important purpose of the
baseline studies is to construct a micro-hydro project with the least amount of impact to the natural environment
from the proposed actions. Any impacts, which cannot be avoided, will need to be mitigated. For example, by
identifying and mapping the vegetation, a penstock route can be chosen to least affect the vegetation and wildlife.
One of the most important pieces of baseline data to obtain is to definitively define the upstream limits of the
existence of important resident and anadromous fish. Other baseline data includes groundwater data such as flow
rates and water levels, amount of sedimentation naturally occurring in the water table, natural erosion processes,
temperature, dissolved oxygen pH, etc. Baseline data also includes terrestrial data such as; important habitat areas,
bald eagle nest survey, vegetation survey, etc. (RCA 2007).
Methodology
The permitting process requires the triad approach: The applicants; the regulating agencies; and the public. The
applicants and the agencies must work with the public for comments on potential projects. This requires a
notification to the agencies and public, public and agency scooping, public comment periods, public hearings, etc.,
for the proposed action. Thus agencies must work closely with the public during the permitting process to ensure the
process is followed correctly (EPA, 2008).
The agency roles and responsibilities are to ensure environmental laws are not violated and as a regulator of
environmental laws. As the regulators of environmental laws, the agencies are responsible for: developing polices
and guidance; issuing permits; performing inspections; providing awareness to the public; attending public meetings
and recording/listening to public comment; writing letters; and enforcement, issuing notice of violations, issuing
compliance orders by consent, and issuing court orders. An example of an agencies role and responsibilities is the
March 2011 45 California Creek Hydroelectric Feasibility Alaska Department of Environmental Conservations six elements of a good regulatory program which includes:
unambiguous statutory authority, documented basis of concern, protective standards, rational regulatory scheme,
documented compliance, and enforcement (Simmons, 2010)(Steinway & Bolts, 2005)(ADEC).
The applicant roles and responsibilities is to figure out what permits are needed for a project. The applicant must do
due diligence in obtaining all the permits required for any discharge or activity which will impact the surrounding
environment. The applicant must contact the agencies to obtain permits. This may require the agencies working
with the applicant and holding public meetings. The applicant is also responsible for paying for the permits and
paying for any baseline studies that may be required prior to obtaining the permits. If the applicant does not obtain
the proper permits they will be breaking the law in accordance with the federal and state environmental statutes
(Simmons, 2010)(Steinway & Botts, 2005).
General Permit Procedures Overview
Should this project move forward, an Alaska Coastal Zone Management (CZM) Questionnaire and possibly a five
megawatt exemption from the Federal Energy Regulatory Commission (FERC) must be completed. A 5 MW
exemption from FERC requires the presence of a physical barrier which separates the reach of the stream affected by
project construction from that below and for the developer to have needed rights and permissions from land owners
to build the project. In the case of California Creek, both these conditions remain to be demonstrated. If the project
fails to qualify for the 5 mw exemption, and if found to be under FERC jurisdiction, the project will be required to go
through the complete FERC licensing process. If FERC finds that they do not have jurisdiction, similar hydroelectric
projects in Alaska are ultimately permitted by various state regulatory agencies and affected land owners for
construction.
These two documents will set the pace for what permits are required from what agencies. FERC has the most
jurisdictions for hydroelectric projects. Pending FERCs decision, other agencies will need to be contacted. These
potential agencies with permitting authorities are, but not limited to:
water right permit from the Alaska Department of Natural Resources (ADNR);
land use permit or other authorization from the Municipality of Anchorage (MOA) Heritage Land Bank;
if any portions of the project fall within the boundaries of Chugach State Park, authorizations(s) will be
required from the Alaska Department of Natural Resources, specifically the Division of Parks and Outdoor
Recreation;
Title 16 fish habitat permit needs to be applied from the Alaska Department of Fish and Game (ADF&G);
USF&WS and National Marine Fisheries Service regarding anadromous fish;
MOA and the Federal Emergency Management Agency (FEMA) regarding flooding issues;
Regulatory Commission of Alaska (RCA) concerning fees;
USF&WS regarding endangered species issues, such as locations of bald eagle nests in accordance with EPA
section 7.
Alaska Department of Environmental Conservation for water quality and possibly water discharge;
US Corp of Engineers for Section 404 dredge and fill permits and wetland determinations;
State Historic Preservation Officer for possible historic and cultural site protection.
March 2011 46 California Creek Hydroelectric Feasibility Permit Information
The following provides more specifics for some of the permits and/or authorizations that might be required. This
section is not intended, nor should it be used as a complete checklist for this or any other project. Each project must
be evaluated on its own merits once Public Scoping of Issues has been completed and more detailed information
about the project is available.
Coastal Project Questionnaire (CPQ) and Certification Statement. Once the specifics of the project are
figured out by the applicant, the CPQ needs to be filled out. The questionnaire will trigger any state or federal
agencies that needs to get involved for permitting. There is no cost to the applicant for the questionnaire. The
agency will contact the applicant in 21 days if it is not filled out correctly. It is important to know the specifics of the
project such as location, flow rates, etc. before the application is filled out. This is important because if the project is
changed after the application is filled out, it can stall the project.
Federal Energy Regulatory Commission. A personal conversation with Edward Abrams of FERC, indicates this
project might qualify for a 5 megawatt (mw) exemption (Abrams, 2010). See a more detailed explanation on the
exemption process under General Permit Procedures Overview above. Before filing for the exemption, the stream
bed/banks and any transmission line locations must be located, all of which should be completed before the CPQ is
filled out. An application for exemption for a small hydroelectric project of 5 MW or less must include the
following:
i. Introductory Statement:
ii. Exhibit A describes the small hydroelectric project and its proposed mode of operation.
iii. Exhibit B provides a general location map that must show the location of the physical structures and their
relationship to the water body and identifiable land marks, land ownership information, and a proposed
project boundary.
iv. Exhibit E, or a preliminary Environmental Assessment (EA) if using an alternative process, is the
environmental report and must reflect pre-filing consultation requirements. Commensurate with the scope
and degree of environmental impact, it must include a description of the projects environmental setting, the
expected environmental impacts, and proposed measures to protect the environment.
v. Exhibit G is a set of drawings showing the project structures and equipment.
vi. Identification of all Indian tribes potentially affected.
vii. Appendix containing evidence that the applicant has the necessary real property interests in any nonfederal
land (18CFR 4,107).
viii. Fish and wildlife agency reimbursement fees must accompany filed applications (18 CFR 4.302).
Alaska Department of Natural Resources (ADNR) Water Right Permit. To get a water right permit, an
application for water rights needs to be submitted to the ADNR office in Anchorage accompanied by the appropriate
filing fee in accordance with 11 AAC 05.010(a)(8). Before the application is filled out the water resources section at
the ADNR needs to be contacted for a pre-application meeting. An application for a water rights reservation filing
fee currently costs $1,500.00. The applicant must also pay for data collection analysis during the certificates review
and pay the cost of legal advertisement to inform the public.
The ADNR reviews the application for accuracy. If ADNR notices any discrepancies, they will open a back and forth
communication with the applicant to remedy any outstanding issues.
March 2011 47 California Creek Hydroelectric Feasibility After the certificate is awarded the applicant may be required to install stream gauges to monitor and report on the
reserved instream flow or level of water in California Creek during various times of the year.
Alaska Department of Fish and Game (ADF&G) Important Habitat and Title 16 Fish Habitat Permit.
The entire Glacier Creek, Alyeska Creek, Crow Creek and California Creek consists of habitat that is utilized by a
variety of wildlife. A review of habitat mapping maintained by the ADF&G does not indicate any critical habitat
areas.
The ADF&G has cataloged California Creek, No. 247-60-10250-2007, as water important for spawning, rearing or
migration of anadromous fishes (Johnson & Klein, 2009). The catalog indicates that Coho and Pink Salmon rearing
occur below the project area. It is not clear whether anadromous and/or important resident fish are located at or
above the potential project area. The ADF&G catalog indicates that spawning may occur above the proposed
Powerhouse location. However, during the field work related to the survey and engineering work associated with
this study there was no indication that was the case because of the steep terrain and existence of relatively dramatic
waterfalls. Based on this conflicting information further field research as part of an environmental analysis will be
necessary to establish the upper limits of high value resident and anadromous fish habitat.
Based on the results of this additional research a Title 16 Fish Habitat Permit may be needed. AS 16.05.841 requires
that a fish way passage is required as part of the Fish Way Act. The Act indicates [t]he fishway shall be kept open,
unobstructed, and supplied with a sufficient quantity of water to admit freely the passage of fish through it.
Since this project is located on an anadromous fish stream, the applicant, at a minimum must notify ADF&G before
any construction commences. The ADF&G will then request information on the project such as: plans and
specifications of construction; date when work will begin, and plans and specifications on how the anadromous fish
will be protected per AS 16.05.841.
The Office of Habitat Management and Permitting issues the fish way permits. The permit review process takes
about 14 days and has no fees associated with it. The application requires:
i. Applicant information
ii. Type and purpose of the project
iii. Location of the project site
iv. Time from for the project
v. Construction methods
vi. Site rehabilitation/restoration plan
vii. Water body characteristics
viii. Hydraulic evaluation
This project may require additional steps to ensure the anadromous and high value resident fish are protected based
on the additional research indicated above. For example, the water intake structure may need to contain a screened-
box enclosure for the protection of fish; the water level of the stream may also need to be regulated to prevent the
desiccation of anadromous fish eggs; stream flow may need to be regulated to prevent sedimentation of anadromous
fish eggs or temperature fluctuations. Lastly, the prevention of super-saturation of dissolved oxygen may also need
to be regulated to protect the anadromous fish (Frost 2010).
March 2011 48 California Creek Hydroelectric Feasibility Municipality of Anchorage (MOA) Flood Hazard Plan Review and Federal Emergency Management
Agency (FEMA) Requirements. Jeff Urbanus, MOA flood hazard permitting, indicates a permit from MOA may
be required if there are any obstruction(s) blocking the flood plains/channels of the creeks. California Creek has
been partially mapped; see the FEMA national flood insurance maps. From the current maps, it does not appear the
project area is within the 100-year floodplain. Thus the MOA will need to, at the minimum, comment on the
location of the project, but a permit should not be required. If it is determined that the project is on a floodplain,
then a flood hazard permit application will need to be filled out from the MOA, which contains FEMA guidelines for
flood resistant materials as part of the National Flood Insurance Program (NFIP) (Urbanus, 2010).
The Regulatory Commission of Alaska (RCA). Currently there is no state water-power licensing program;
instead this is FERCs jurisdiction. However, RCA may require a fee for the power generation depending on the
owner of the project (RCA, 2007).
U.S. Fish and Wildlife Service (USFWS). No permits are expected to be required since the project is not on
federal land and no endangered species are known to exist within the project area. They, along with the National
Marine Fisheries Service, may place mandatory conditioning license clauses or requirements for any developments on
anadromous streams.
A bald eagle nest inventory will need to be completed to ensure no nests are located within the area. If a bald eagle
nest is encountered within the area, the Bald Eagle Management Guidelines and Conservation will need to be followed.
Lastly, in accordance under the Migratory Bird Treaty Act (MBTA)(16 U.S.C. 703) no vegetation clearing can occur
during the migratory bird nesting period, which currently is from May 1st to July 15th.
National Marine Fisheries Service (NMFS). No permits will be required from NMFS. However, as
mentioned above, the NMFS and the USFWS may place mandatory conditioning license clauses or requirements for
any developments on anadromous streams.
Alaska Department of Environmental Conservation (ADEC). Alan Kukla, ADEC Water Division, states
that micro-hydroelectric projects are FERCs or other agencies jurisdiction; the ADEC does not do any of the
permitting. He stated that although water will be removed and discharged back into the creek, the discharge will not
be altered from its natural state which could be a violation water quality standards. In other words the discharge
from micro-projects will not; alter water temperature; introduce any contaminates; introduce any particulates;
increase the biological oxygen demand; etc. Therefore it falls under FERCs jurisdiction. However, if the project
does alter water quality standards, the ADEC will need to regulate the discharge. At a minimum, the ADEC Water
Quality division will need to be contacted with project specifics (KUKLA, 2010).
U.S. Army Corp of Engineers (USACE). It appears that a section 404 permit may be required. This project is
located within water of the US, but not navigable waters of the US. There are known wetlands nor should wetlands
need to be crossed during the projects construction. However, a complete field inventory has not been conducted.
Based on the preliminary engineering information contained earlier in this report, it does not appear that California
Creek itself will be dredged or filled. It is likely though that the intake structure construction will necessitate
obtaining a Section 404 permit. At a minimum, the USACE will need to be consulted as part of the agency scoping
process related to necessary further environmental analysis (Keller, 2010).
March 2011 49 California Creek Hydroelectric Feasibility C o n c l u s i o n s a n d R e c o m m e n d a t i o n s
More detailed study of hydroelectric power generation from California Creek appears to be a reasonable investment
considering prospective benefits to residents of housing developments proposed in the immediate vicinity.
The availability of power from a micro-hydropower facility on California Creek, and possibly other sources in the
Girdwood Valley, such as Alyeska Creek, Crow Creek, and Virgin Creek would be seasonal, but when available
would provide less expensive electricity than from present commercial power sources. Utility costs will follow the
price of natural gas, which is expected decrease in availability and substantially rise in the foreseeable future.
Known environmental impacts of construction and operation have been minimized in the proposed preliminary
designs, but further investigations, especially as related to anadromous and important resident fish are warranted and
necessary.
Steps that should follow this investigation and report include:
Refined design of intake, penstock, and powerhouse.
Complete cost analysis of all components.
Market analysis for power produced in terms of the scale and schedule of proposed residential developments
in the vicinity of California Creek, and possibly other micro-hydroelectric sources in the area.
Base line environmental studies to include agency and public scoping.
Discussions with authorities involved with regulating consumer power costs to assure a fair recovery of
capital and operating costs can be achieved for small-scale, low-impact, renewable power production, in
particular moving towards net metering.
March 2011 50 California Creek Hydroelectric Feasibility R e f e r e n c e s
Abrams, E. (2010, January 15). FERC Jurisdiction. (G. Lindren, Interviewer)
Agnew-Beck, 2006. Crow Creek Neighborhood Land Use Plan, Final Plan, Agnew-Beck Consulting, LLC,
Prepared for Heritage Land Bank, Municipality of Anchorage
ADEC. (1010, March 10). Poster in the 1st floor small conference room, 555 Cordova Street, Anchorage, AK. (G.
Lindren)
ASCE, 1989. Small Scale Hydro, Civil Engineering Guidelines for Planning and Designing Hydroelectric
Developments, American Society of Civil Engineers, New York, NY
Daly, Steven, 1991. Frazil Ice Blockage of Intake Trash Racks, Cold Regions Technical Digest No. 91-1,
Cold Regions Research and Engineering Laboratory, Hanover, NH
EPA, (2008, May 8). Terms of Environment: Glossary, Abbreviations and Acronyms. Retrieved March 3, 2010 from EPA:
http://www.epa.gov/OCEPAaterms.pterms.html.
ESHA, 1998. Laymans Guidebook on how to develop a small hydro site, 2nd ed., European Small
Hydropower Association, Brussels
Frost, W. (2009, March)). Habitat Biologist, ADF&G, (G. Lindren, Interviewer)
Glass, R., and Brabets, T., 1987. Summary of Water Resources Data for the Girdwood-Alyeska Area, Alaska,
Open File Report 87-678, US Geological Survey, Anchorage
Hull, Wesley, 1989. Geometric Geodetic Accuracy Standards and Specifications for Using GPS Relative
Positioning Techniques, Federal Geodetic Control Committee Technical Report, Version 5.0
Humphreys, H., Sigurdsson, G., and Owen, H., 1970. Model Test Results of Circular, Square, and
Rectangular Forms of Drop-Inlet Entrance to Closed-Conduit Spillways, Illinois State Water Survey,
Urbana
Inverson, Allen, 1986. Micro-Hydropower Sourcebook: A Practical Guide to Design and Implementation
in Developing Countries, NRECA International Foundation
Johnson, J., & Klein, K. (2009, March). Catalog of Waters Important for Spawning, Rearing or Migration of Anadromous
Fishes Southcentral Regon, Effective June 1, 2009. Retrieved April 15, 2010, from Alaska Department of Fish and
Game, Divisions of Sport Fish and Habitat: http://www.sf.adfg.state.ak.us/SARR/AWC/index.cfm/FA/main.overview
Keller, B. (2010, March23). USACE Regulatory Division. (G. Lindren, Interviewer)
Kukla, A. (2010, March 15). Groundwater discharge. (G. Lidren, Interviewer)
March 2011 51 California Creek Hydroelectric Feasibility McLean, Robert, 1998. Water Intake Structures: An Alternative to Traditional Screened-Box Enclosures
for the Protection of Fish, Technical Report 97-8, Alaska Dept. of Fish and Game, Juneau
RCA. (2007, September 1). Water Power Development. Retrieved April 17, 2010, from Regulatory Commission of
Alaska: http://rca.alaska.gov/RCAWeb/Programs/Water Power Development.aspx
SCS, 1969.Entrance Head Losses in Drop Inlet Spillways, Design Note No. 8, Soil Conservation Service,
US Dept. Agriculture
Shennan, I., Hamilton, S., and Long, A., 2004. Recurrent Holocene Paleoseismicity and Associated Land/Sea Level
Changes in the Greater Anchorage Area, Alaska Division of Geological and Geophysical Surveys, Fairbanks
Simmons, L. (2010, February 2). Environmental System, three legged chair. (G. Lidren, Interviewer)
Snay, R., and Soler, T., 2008. Continuously Operating Reference Station (CORS): History, Applications,
and Future Enhancements, NOAA/NGS Technical Report
Steinway, D., & Botts, B. (2005). Fundamentals of Environmental Law. In T. Sullivan, Environmental Law
Handbook, (pp 1-4). Lanham: Government Institutes.
UAA School of Engineering. (2009). Feasibility Report Girdwood Renewable Energy Research & Discovery Center,
University of Alaska Anchorage
Urbanus, J. (2010, March 23). MOA Flood Permitting Procedures. (G. Lidren, Interviewer)
USACE, 1990. Hydraulic Design of Spillways; Chapter 5 - Specialized Spillways, EM 1110-2-1603, US
Army Corps of Engineers, Washington, DC
Yanity, Brian, 2007. California Creek Hydroelectric Project Pre-feasibility Study, prepared for Heritage
Land Bank, Municipality of Anchorage
Page A-1
A p p e n d i c e s
MEETINGS AND PRESENTATIONS TO DATE .......................................................... A-2
SAMPLE CALCULATIONS WITH FIXED (CONSTANT)FLOW
RATE OF 5 CFS (475 FT. GROSS HEAD) ...................................................... A-3
SAMPLE CALCULATIONS WITH A FIXED (CONSTANT) FLOW
RATE OF 5 CFS (325 FT. GROSS HEAD) ..................................................... A-4
AMORTIZATION CHART FOR ECONOMIC ANALYSIS ................................................. A-5
ECONOMIC ANALYSIS AND AMORITIZATION CHART (GROSS HEAD 325 FT.) .............. A-8
Price Quote and Specifications of Pelton Wheel A-11
HDPE PIPE; TYPICAL DIMENSIONS AND ASSOCIATED PRESSURE RATINGS ............ A-13
STEEL PIPE BLACK AND ZINC COATED,WELDED
CONFORMING TO ASTM A53-1993 ..................................................... A-14
INDEX MAP OF HORIZONTAL CONTROL POINT POSITIONS
ALONG CALIFORNIA CREEK .................................................................... A-15
Coordinates of Survey Points Set along California Creek A-17
Page A-2
M e e t i n g s a n d P r e s e n t a t i o n s t o D a t e
April 3, 2010 Presentation to Girdwood 2020 Board of Directors explain project objectives.
April 8, 2010 Public open house presentation at Girdwood Community Center to explain project objectives
and to listen to public concerns objectives.
March 23, 2010 Agency meeting to determine possible permit requirements and environmental concerns.
Attendees:
ADF&G, Habitat Biologist Will Frost
MMS (now BOEMRE), Deputy Director Jeffery Loman
PRA, GIS Analyst Alicia Orange
USFWS, Anchorage Office Field Supervisor Ann Rappaport
Municipality of Anchorage, Heritage Land Bank Alison Smith
USACE, Regulatory Branch - Bill Keller
Water Resource Engineer, Joe Klein
USFS, Environmental Coordinator Elizabeth Brann
NOAA, Fishery Biologist, Environmental Compliance Steven Davis
UAA, Civil Engineering Dept. Chair Dr. Orson Smith
ADEC, Div. of Water Program Manager Sharmon Stambaugh
USFS Kate Walker
UAA CE 438 Student Gabrielle St. Pierre
UAA, Adjunct Instructor Leslie Simmons
May 1, 2010 Update presentation to Girdwood 2020 Board of Directors discussing project progress.
Nov 15, 2010 Presentation to Girdwood Board of Supervisors GBOS discussing results of preliminary
engineering and environmental analysis.
Page A-3
Sample Calculations with fixed (constant) flow rate of 5cfs (475 ft gross head)
Water properties
Density (kg/m3) 999
Dyn Visc (N s/m^2) 0.00112
Flowrate (L/s) 141.5842
Q (m^3/s) 0.1415842
Pipe dia (in) 14
Pipe dia (m) 0.3556
Pipe X-sectional area
(m^2) 0.09931467
Velocity (m/s) 1.42561221
Reynold's Number 452179.244
Finding friction factor
Laminar flow 0.00014154
Turbulent flow
Equiv Roughness (mm) 0.045 Commercial Steel
Equiv Roughness (m) 0.000045
e/D 0.00012655
Guess friction factor
0.0135
Calculate nozzle velocity
g (m/s^2) 9.81
delta z (m) 144.78
f (from Reynold's
number) 0.0135
Length of pipe (m) 1554.48
Nozzle diameter (m) 0.05
H (m) 6.11307516
Nozzle Velocity (m/s) 52.16
Pmax (W) 192407
Turbine efficiency 82%
Pmax (W) 157773
Page A-4
Sample Calculations with fixed (constant) flow rate of 5cfs (325 ft gross head)
Water properties
Density (kg/m3) 999
Dyn Visc (N s/m^2) 0.00112
Flowrate (L/s) 141.5842
Q (m^3/s) 0.1415842
Pipe dia (in) 14
Pipe dia (m) 0.3556
Pipe X-sectional area
(m^2) 0.09931467
Velocity (m/s) 1.42561221
Reynold's Number 452179.244
Finding friction factor
Laminar flow 0.00014154
Turbulent flow
Equiv Roughness (mm) 0.045 Commercial Steel
Equiv Roughness (m) 0.000045
e/D 0.00012655
Guess friction factor
0.0135
Calculate nozzle velocity
g (m/s^2) 9.81
delta z (m) 99.06
f (from Reynold's
number) 0.0144
Length of pipe (m) 579.12
Nozzle diameter (m) 0.05
H (m) 2.27742016
Nozzle Velocity (m/s) 43.576073
Pmax (W) 134290
Turbine efficiency 75%
Pmax (W) 100717
Page A-5
Amortization chart for Economic Analysis
Month Payment Interest Principal Extra 278,300
1 1626.914 1159.583 467.3308 2055 275,778
2 1626.914 1149.074 477.8405 2055 273,245
3 1626.914 1138.52 488.394 2055 270,701
4 1626.914 1127.923 498.9914 2055 268,147
5 1626.914 1117.281 509.6331 2055 265,583
6 1626.914 1106.595 520.319 2055 263,007
7 1626.914 1095.865 531.0495 2055 260,421
8 1626.914 1085.089 541.8247 2055 257,825
9 1626.914 1074.269 552.6448 2055 255,217
10 1626.914 1063.404 563.51 2055 252,598
11 1626.914 1052.494 574.4205 2055 249,969
12 1626.914 1041.538 585.3764 2055 247,329
13 1626.914 1030.536 596.378 2055 244,677
14 1626.914 1019.489 607.4254 2055 242,015
15 1626.914 1008.395 618.5188 2055 239,341
16 1626.914 997.2556 629.6585 2055 236,657
17 1626.914 986.0695 640.8446 2055 233,961
18 1626.914 974.8368 652.0773 2055 231,254
19 1626.914 963.5573 663.3567 2055 228,535
20 1626.914 952.2309 674.6832 2055 225,806
21 1626.914 940.8572 686.0569 2055 223,065
22 1626.914 929.4361 697.478 2055 220,312
23 1626.914 917.9674 708.9466 2055 217,548
24 1626.914 906.451 720.4631 2055 214,773
25 1626.914 894.8866 732.0275 2055 211,986
26 1626.914 883.274 743.6401 2055 209,187
27 1626.914 871.613 755.3011 2055 206,377
28 1626.914 859.9034 767.0107 2055 203,555
29 1626.914 848.145 778.7691 2055 200,721
30 1626.914 836.3376 790.5765 2055 197,875
31 1626.914 824.4811 802.433 2055 195,018
32 1626.914 812.5751 814.339 2055 192,149
33 1626.914 800.6195 826.2946 2055 189,267
34 1626.914 788.6141 838.3 2055 186,374
35 1626.914 776.5587 850.3554 2055 183,469
36 1626.914 764.453 862.461 2055 180,551
37 1626.914 752.297 874.6171 2055 177,622
38 1626.914 740.0902 886.8239 2055 174,680
39 1626.914 727.8326 899.0815 2055 171,726
Page A-6
40 1626.914 715.5239 911.3901 2055 168,759
41 1626.914 703.164 923.7501 2055 165,781
42 1626.914 690.7525 936.1616 2055 162,789
43 1626.914 678.2894 948.6247 2055 159,786
44 1626.914 665.7743 961.1398 2055 156,770
45 1626.914 653.207 973.7071 2055 153,741
46 1626.914 640.5874 986.3267 2055 150,700
47 1626.914 627.9152 998.9989 2055 147,646
48 1626.914 615.1902 1011.724 2055 144,579
49 1626.914 602.4122 1024.502 2055 141,499
50 1626.914 589.5809 1037.333 2055 138,407
51 1626.914 576.6962 1050.218 2055 135,302
52 1626.914 563.7578 1063.156 2055 132,184
53 1626.914 550.7655 1076.149 2055 129,053
54 1626.914 537.719 1089.195 2055 125,908
55 1626.914 524.6182 1102.296 2055 122,751
56 1626.914 511.4628 1115.451 2055 119,581
57 1626.914 498.2526 1128.661 2055 116,397
58 1626.914 484.9873 1141.927 2055 113,200
59 1626.914 471.6668 1155.247 2055 109,990
60 1626.914 458.2908 1168.623 2055 106,766
61 1626.914 444.859 1182.055 2055 103,529
62 1626.914 431.3713 1195.543 2055 100,279
63 1626.914 417.8274 1209.087 2055 97,014
64 1626.914 404.227 1222.687 2055 93,737
65 1626.914 390.57 1236.344 2055 90,445
66 1626.914 376.856 1250.058 2055 87,140
67 1626.914 363.085 1263.829 2055 83,822
68 1626.914 349.2565 1277.658 2055 80,489
69 1626.914 335.3704 1291.544 2055 77,142
70 1626.914 321.4265 1305.488 2055 73,782
71 1626.914 307.4245 1319.49 2055 70,407
72 1626.914 293.3641 1333.55 2055 67,019
73 1626.914 279.2451 1347.669 2055 63,616
74 1626.914 265.0674 1361.847 2055 60,199
75 1626.914 250.8305 1376.084 2055 56,768
76 1626.914 236.5343 1390.38 2055 53,323
77 1626.914 222.1786 1404.736 2055 49,863
78 1626.914 207.763 1419.151 2055 46,389
79 1626.914 193.2874 1433.627 2055 42,900
80 1626.914 178.7514 1448.163 2055 39,397
Page A-7
81 1626.914 164.1549 1462.759 2055 35,879
82 1626.914 149.4976 1477.417 2055 32,347
83 1626.914 134.7792 1492.135 2055 28,800
84 1626.914 119.9995 1506.915 2055 25,238
85 1626.914 105.1581 1521.756 2055 21,661
86 1626.914 90.25499 1536.659 2055 18,070
87 1626.914 75.28975 1551.624 2055 14,463
88 1626.914 60.26215 1566.652 2055 10,841
89 1626.914 45.17193 1581.742 2055 7,205
90 1626.914 30.01884 1596.895 2055 3,553
91 1626.914 14.80261 1612.111 2055 114
(Numbers shown in dollars)
Page A-8
Economic analysis and amortization chart (gross head, 325 ft)
Annual Electricity Generated = 64.5 kW * 4800 = 309600 kWh per year
$/kWh = Annual Payment for Capital Cost/ Annual Electricity Demand = $13,505/309600 kWh = 0.0436
$/kWh = Annual Payment for O & M/ Annual Electricity Demand = $9,625/309600 kWh = 0.031
Price difference ($/kWh) = 0.118872 -0.0747 = 0.04418
Annual Savings = Price difference ($/kWh) * Annual Electricity Demand (kWh) = 0.04418* 309600 = $13,678
Month Payment Interest Principal Extra 192,515
1 1125.424 802.1458 323.2777 1139.87 191,052
2 1125.424 796.0494 329.3741 1139.87 189,583
3 1125.424 789.9275 335.496 1139.87 188,107
4 1125.424 783.7802 341.6433 1139.87 186,626
5 1125.424 777.6072 347.8163 1139.87 185,138
6 1125.424 771.4085 354.015 1139.87 183,644
7 1125.424 765.184 360.2395 1139.87 182,144
8 1125.424 758.9335 366.49 1139.87 180,638
9 1125.424 752.657 372.7665 1139.87 179,125
10 1125.424 746.3544 379.0691 1139.87 177,606
11 1125.424 740.0255 385.3981 1139.87 176,081
12 1125.424 733.6702 391.7533 1139.87 174,549
13 1125.424 727.2884 398.1351 1139.87 173,011
14 1125.424 720.8801 404.5435 1139.87 171,467
15 1125.424 714.445 410.9785 1139.87 169,916
16 1125.424 707.9831 417.4404 1139.87 168,359
17 1125.424 701.4943 423.9292 1139.87 166,795
18 1125.424 694.9785 430.445 1139.87 165,225
19 1125.424 688.4355 436.988 1139.87 163,648
20 1125.424 681.8653 443.5582 1139.87 162,064
21 1125.424 675.2677 450.1558 1139.87 160,474
22 1125.424 668.6426 456.7809 1139.87 158,878
23 1125.424 661.9899 463.4337 1139.87 157,274
24 1125.424 655.3094 470.1141 1139.87 155,664
25 1125.424 648.6012 476.8224 1139.87 154,048
26 1125.424 641.8649 483.5586 1139.87 152,424
27 1125.424 635.1007 490.3229 1139.87 150,794
28 1125.424 628.3082 497.1153 1139.87 149,157
29 1125.424 621.4874 503.9361 1139.87 147,513
30 1125.424 614.6382 510.7853 1139.87 145,863
31 1125.424 607.7605 517.663 1139.87 144,205
Page A-9
32 1125.424 600.8541 524.5694 1139.87 142,541
33 1125.424 593.9189 531.5046 1139.87 140,869
34 1125.424 586.9549 538.4686 1139.87 139,191
35 1125.424 579.9618 545.4617 1139.87 137,506
36 1125.424 572.9396 552.4839 1139.87 135,813
37 1125.424 565.8881 559.5354 1139.87 134,114
38 1125.424 558.8073 566.6163 1139.87 132,407
39 1125.424 551.6969 573.7266 1139.87 130,694
40 1125.424 544.5569 580.8666 1139.87 128,973
41 1125.424 537.3872 588.0363 1139.87 127,245
42 1125.424 530.1876 595.236 1139.87 125,510
43 1125.424 522.958 602.4656 1139.87 123,768
44 1125.424 515.6982 609.7253 1139.87 122,018
45 1125.424 508.4082 617.0153 1139.87 120,261
46 1125.424 501.0879 624.3356 1139.87 118,497
47 1125.424 493.737 631.6865 1139.87 116,725
48 1125.424 486.3555 639.068 1139.87 114,946
49 1125.424 478.9433 646.4802 1139.87 113,160
50 1125.424 471.5002 653.9233 1139.87 111,366
51 1125.424 464.026 661.3975 1139.87 109,565
52 1125.424 456.5208 668.9028 1139.87 107,756
53 1125.424 448.9842 676.4393 1139.87 105,940
54 1125.424 441.4163 684.0073 1139.87 104,116
55 1125.424 433.8168 691.6068 1139.87 102,285
56 1125.424 426.1856 699.2379 1139.87 100,445
57 1125.424 418.5227 706.9009 1139.87 98,599
58 1125.424 410.8278 714.5957 1139.87 96,744
59 1125.424 403.1008 722.3227 1139.87 94,882
60 1125.424 395.3417 730.0818 1139.87 93,012
61 1125.424 387.5502 737.8733 1139.87 91,134
62 1125.424 379.7263 745.6972 1139.87 89,249
63 1125.424 371.8698 753.5537 1139.87 87,355
64 1125.424 363.9805 761.443 1139.87 85,454
65 1125.424 356.0584 769.3651 1139.87 83,545
66 1125.424 348.1032 777.3203 1139.87 81,628
67 1125.424 340.1149 785.3086 1139.87 79,702
68 1125.424 332.0934 793.3302 1139.87 77,769
69 1125.424 324.0384 801.3852 1139.87 75,828
70 1125.424 315.9498 809.4737 1139.87 73,879
71 1125.424 307.8275 817.596 1139.87 71,921
72 1125.424 299.6714 825.7521 1139.87 69,956
Page A-10
73 1125.424 291.4813 833.9422 1139.87 67,982
74 1125.424 283.2571 842.1664 1139.87 66,000
75 1125.424 274.9986 850.4249 1139.87 64,009
76 1125.424 266.7057 858.7178 1139.87 62,011
77 1125.424 258.3783 867.0452 1139.87 60,004
78 1125.424 250.0161 875.4074 1139.87 57,989
79 1125.424 241.6191 883.8044 1139.87 55,965
80 1125.424 233.1872 892.2363 1139.87 53,933
81 1125.424 224.7201 900.7035 1139.87 51,892
82 1125.424 216.2177 909.2058 1139.87 49,843
83 1125.424 207.6799 917.7437 1139.87 47,786
84 1125.424 199.1065 926.3171 1139.87 45,719
85 1125.424 190.4974 934.9262 1139.87 43,645
86 1125.424 181.8524 943.5712 1139.87 41,561
87 1125.424 173.1714 952.2522 1139.87 39,469
88 1125.424 164.4542 960.9693 1139.87 37,368
89 1125.424 155.7007 969.7228 1139.87 35,259
90 1125.424 146.9107 978.5128 1139.87 33,140
91 1125.424 138.0841 987.3394 1139.87 31,013
92 1125.424 129.2208 996.2028 1139.87 28,877
93 1125.424 120.3204 1005.103 1139.87 26,732
94 1125.424 111.3831 1014.04 1139.87 24,578
95 1125.424 102.4084 1023.015 1139.87 22,415
96 1125.424 93.39641 1032.027 1139.87 20,243
97 1125.424 84.34684 1041.077 1139.87 18,062
98 1125.424 75.25956 1050.164 1139.87 15,872
99 1125.424 66.13442 1059.289 1139.87 13,673
100 1125.424 56.97126 1068.452 1139.87 11,465
101 1125.424 47.76992 1077.654 1139.87 9,247
102 1125.424 38.53023 1086.893 1139.87 7,020
103 1125.424 29.25205 1096.171 1139.87 4,784
104 1125.424 19.93522 1105.488 1139.87 2,539
105 1125.424 10.57956 1114.844 1139.87 284
106 1125.424 1.184914 1124.239 1139.87 1,980
(Numbers shown in dollars)
Page A-11
Price quote and specifications of Pelton wheel
Page A-12
Page A-13
HDPE P IPE ; T YPICAL DIMENSIONS AND ASSOCIATED PRESSURE RATING
GS FOR HDPE PIPE .
Blue indicates most commonly available pipe sizes.
Page A-14
Upto 48.3 mm ± 40 mm Thickness : ± 12.5%
Above 48.3 mm ± 1% Weight Weight : Individual Length ± 10%
S t e e l P i p e B l a c k a n d Z i n c C o a t e d , W e l d e d C o n f o r m i n g T o A S T M A 5 3 -1 9 9 3
DIMENSION
SIZE
OUTSIDE DIAMETER THICKNESS WEIGHT HYDRO TEST PRESSURE
GRADE-A GRADE-2
Inch mm mm kg/mtr KPa KPa
1/2 21.3 2.77 1.27 4830 4830
3/4 26.7 2.87 1.69 4830 4830
1 33.4 3.38 2.50 4830 4830
1-1/4 42.2 3.56 3.39 8270 8960
1-1/2 48.3 3.68 4.05 8270 8960
2 60.3 3.91 5.44 5860 17240
2-1/2 73.0 5.16 8.63 17240 17240
3 88.9 5.49 11.29 15310 17240
4 114.3 5.56 40.91 12770 14070
4 114.3 6.02 16.07 13100 15240
5 141.3 6.55 21.77 11510 13440
6 168.3 7.11 28.26 10480 12270
8 219.1 6.35 33.31 7170 8410
8 219.1 7.04 36.31 7800 9310
8 219.1 8.18 42.55 9240 10820
10 273.0 6.35 41.75 5790 6760
10 273.0 7.80 51.01 7100 8270
10 273.0 9.27 60.29 8410 9860
12 323.8 6.35 49.71 4900 5650
12 323.8 8.38 65.18 6410 7520
12 323.8 9.52 73.78 7310 8550
14 355.6 6.35 54.69 4410 5170
14 355.6 7.92 67.90 5520 6780
14 355.6 9.52 81.25 6620 7720
Page A-15
I NDEX MAP OF HORIZONTAL SURVEY POINT POSITIONS ALONG C ALIFORNIA CREEK .
Page A-16
I NDEX MAP OF HORIZONTAL SURVEY POINT POSITIONS ALONG C ALIFORNIA CREEK .
Page A-17
C OORDINATES OF SURVEY POINTS SET ALONG C ALIFORNIA C REEK .