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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 Page i 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 O’Brien, 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. Page ii 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 Page iii 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 CREEK–APRIL 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 Page iv 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 Page v 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 turbine’s 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 utility’s 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. Lidren’s 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 FERC’s 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 project’s 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 FERC’s 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 FERC’s 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 FERC’s 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. “Layman’s 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 .