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Home My WebLink AboutAlaska Village Electric Cooperative Old Harbor Hydroelectric Project 2011lSO 9001 Alaska Village Electric Cooperative Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report FERC Project Number P-13272 Alaska Energy Authority REF Grant 2195431 Project Permitee: ALASKA VILLAGE ELECTRIC COOPERATIVE Anchorage, Alaska July, 2011 ~HATCH™ Table of Contents Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Terms, Acronyms, and Abbreviations ........................................................................................................... iv 1. Introduction ............................................................................................................................................ 1 2. Feasibility Issues ...................................................................................................................................... 1 2.1 Project Size .................................................................................................................................... 2 2.2 Turbine Configuration .................................................................................................................... 3 3. Cost Information ..................................................................................................................................... 4 3. 1 Overview ....................................................................................................................................... 4 3.2 Schedule ........................................................................................................................................ 5 3.3 Equipment and shipping ................................................................................................................. 5 3.4 Powerhouse ................................................................................................................................... 6 3.5 Turbine Cost .................................................................................................................................. 6 3.6 Intake ............................................................................................................................................. 6 3.7 Pipeline ......................................................................................................................................... 7 3.8 Transmission and Roads ................................................................................................................. 7 3.9 Indirect Costs ................................................................................................................................. 8 4. Power Study ............................................................................................................................................ 9 4.1 Methodology ................................................................................................................................. 9 4.2 Old Harbor Demand ...................................................................................................................... 9 4.3 Hydrology .................................................................................................................................... 11 4.4 Power Production ........................................................................................................................ 13 4.5 Project Selection .......................................................................................................................... 14 5. Results······························································"························································ ............................ 16 5.1 Cost Comparison .......................................................................................................................... 16 5.2 Cost Detail .................................................................................................................................... 16 5.3 Project Benefits ............................................................................................................................ 1 7 6. Economic Analysis ................................................................................................................................. 19 6.1 Diesel Integration ......................................................................................................................... 19 6.2 Economic inputs .......................................................................................................................... 19 6.3 Economic Results ......................................................................................................................... 20 6.4 Sensitivity Analysis ....................................................................................................................... 21 7. Conclusions and Recommendations ...................................................................................................... 22 7.1 Conclusions ................................................................................................................................. 22 7.2 Recommendations ....................................................................................................................... 22 8. References ............................................................................................................................................. 23 ISO 9001 'i2"'1 WorkingTogethet ;;:) IW~lY Page ii v Hatch 201 'i07 Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Appendix A -Opinion of Probable Cost -525 kW Project with 50% Installed Capacity .......................... A-1 Appendix B -Construction Schedules ........................................................................................................ B-1 Appendix C-Project Drawings .................................................................................................................. C-1 Appendix D-Project Description ............................................................................................................. D-1 Appendix E-Mountain Creek Hydrology Report, Old Harbor, Alaska ...................................................... E-1 Table 1 -Turbine and Generator Price Schedule ............................................................................................ 6 Table 2 lndirectCosts .................................................................................................................................. 8 Table 3 -Old Harbor Demand Summary ..................................................................................................... 1 0 Table 4-Adjustment Factors for Measured Stream Flows at Intake .............................................................. 12 Table 5-Pipe Selection Along Project Alignment. ....................................................................................... 13 Table 6-Pipe Diameters, Flows, Losses, and Power Output.. ...................................................................... 14 Table 7 -Project Alternatives Comparison ................................................................................................... 16 Table 8-Opinion of Probable Cost Summary-525 kW Project with 50% Installed Capacity ..................... 16 Table 9-Annual Fuel Savings with Hydro Project ....................................................................................... 17 Table 10-Economic Parameters .................................................................................................................. 20 Table 11-Economic Summary .................................................................................................................... 21 Table 12-Benefit to Cost Ratio Sensitivity Analysis ..................................................................................... 21 Table 13-Monthly Average Mountain Creek In-stream Flow and Diversion Potential (cfs) ......................... D-2 Figure 1 -Project Capacity and ln5talled Capacity ......................................................................................... 4 Figure 2 -Photo of Water Tank Access Road and Quarry at Beginning of Project (Old Harbor Native Corp) .. 8 Figure 3-Old Harbor Average Daily Demand Fluctuations ......................................................................... 10 Figure 4 -Old Harbor Project Hydrograph and Approximate Power Potential ............................................. 12 Figure 5 -Flow Duration Curve for the East Fork of Mountain Creek ........................................................... 12 Figure 6 -Old Harbor Hydro Annual Energy Potential ................................................................................. 14 Figure 7-Project Optimization Chart .......................................................................................................... 15 Figure 8-Hydro Output (Adjusted Hydrology Data) and Diesel Generation Requirements ......................... 18 Figure 9-Hydro Output (Unadjusted Hydrology Data) and Diesel Generation Requirements ..................... 18 Figure 10 Chart of Mountain Creek In-stream Flow and Diversion Potential (cfs) ..................................... D-3 ISO 9001 """"' WorklngTogether ;;:? SAfElY Page iii ©Hale'! 2011/07 ~HATCH™ Terms, Acronyms, and Abbreviations TERM AEA AVEC BTU cfs cyd ea FERC gal HOPE ID kVA kW kWh lb mi mmBTU mo O&M OD OPC SDR sq ft sq mi sq yd ISO 9001 MEANING Alaska Energy Authority Alaska Village Electric Cooperative British Thermal Unit Cubic feet per second Cubic yards Each Federal Energy Regulatory Commission Gallon High density polyethylene Inside diameter Kilo Volt-Amps Kilo Watt (1 000 Watts) Kilo Watt-hours Pound Mile 1 million BTU's Month Operation and Maintenance Outside Diameter Opinion of Probable Cost Sidewall Diameter Ratio Square feet Square mile Square yard """"" WorkingTogetn<u V SAFUY Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Pageiv ©Hatch 2011/07 1. Introduction Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report This feasibility study and cost estimate has been prepared for Alaska Village Electric Cooperative (AVEC) to facilitate project financing, permitting, and final design. The scope of this report is primarily limited to a technical analysis of costs, selection of project size, and estimate of displaced diesel generated electrical energy. More general information on the Old Harbor project can be found in the Federal Energy Regulatory Commission (FERC) e-library under the current license number P-13272. The study is based on preliminary concept drawings and assumed construction methods. The study describes various project alternatives, analyzes the amount of power produced by each alternative, estimates the cost of each alternative, and provides a recommended project configuration. The report is organized with an overview of the primary issues related to feasibility, discussion of cost estimating and pricing details for major components followed by the power study methodology and the analysis of demand, hydrology, hydroelectric power modeling, and a rationale for selection of a project size. Finally, a comparison of the alternatives is provided with a discussion of the results of the study and details of the project benefits and results of the economic analysis. 2. Feasibility Issues Of the many issues that determine the feasibility and selection of project size to construct, this report focuses on the cost, energy, and economic issues. The broader range of issues relating to the development are briefly addressed below. • Geotechnical: Soils in Old Harbor consist of a uniform layer of organics and peat approximately 2 feet deep overlying rock formations. • Environmental: The Old Harbor project diverts water from the East Fork of Mountain Creek to the Lagoon Creek basin for power production. Extensive environmental investigations were performed as part of the previous FERC licensing effort, P-11690. A final environmental assessment was issued as part of the FERC issued original license for a 500 kW project utilizing 13.2 ds. A summary of this work is included in the Preliminary Application Document and the results of additional investigations will be submitted under the current licensing effort. Documentation sources are found in the reference section. • Site Control: Acquisition of property rights will be required from the US Fish and Wildlife ISO 9001 Service, the State of Alaska, Old Harbor Native Corporation, and the City of Old Harbor. Acquisition is dependent on AVEC receiving a license to construct from FERC, a Right of Way permit from the USFWS, and a conservation easement waiver from the Exxon Valdez Trustee Council. The previously licensed project received, or was close to receiving, these and other property permissions therefore it is expected that the same will come about through the licensing process for this project. ~Working Together ;oo s.vm Page 1 ®Hatch 2011/07 ~ HATCHTV Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report • Permitting: Permitting follows the FERC licensing effort as well. The final environmental assessment will form the basis for the FERC license, USFWS Right of Way permit, USACE permits, and permits from the State of Alaska and Kodiak Island Borough. • Cultural: Cultural resources investigations have been performed as part of the FERC licensing process and reports of investigations and recommendations can be obtained through the FERC elibrary system. • Operation and Maintenance: AVEC will be responsible for operation and maintenance of the project. Details on O&M will materialize at the end of the FERC licensing process and design effort where any required monitoring and mitigation will be determined. An analysis of O&M related to the existing diesel plant and the proposed hydro is included in this report. The long term operation and maintenance of the hydroelectric project will be less than that of diesel operation. • Financing and Economics: A brief analysis of the economics is included in this report but final financing terms and economic evaluation will be a work in progress that will also depend on the outcome of the licensing and efforts. • Conceptual Design: Conceptual plan maps are included in Appendix C along with conceptual drawings for the intake and the access trail. While the conceptual design drawings are preliminary, this report is based on a detailed analysis of pipeline and turbine performance. The high level of detail in the analysis is expected to approximate actual project operation closely. 2.1 Project Size The initial analysis found that even the smallest project configuration considered would displace about 90% of Old Harbor's current diesel generation. After the cost estimate was completed, it was also apparent that construction involved a large amount of fixed costs that were independent of project size. Consequently, increasing the capacity of the project well above current demand requirements could be done with only small incremental increases in total cost. Due to the high overall cost of the project and the relatively small demand requirements, configuring the project to be as economical as possible is also a critical factor. Determining the size of project to construct became a central issue of the analysis. Future demand growth is a key factor in determining overall economics and project size. The estimation of demand growth is quite difficult because it is highly dependent on future funding scenarios, population, industrial and commercial development, and the cost of fuel over a very long time period. In lieu of considering potential demand growth, this report focuses on selecting a project size determined by maximizing energy output with the least capacity and cost. Implicit with this assumption is that future load growth, although undefined at this point, will occur if this project is constructed. This approach results in a project size that is generally consistent with past project development efforts1 • 1 Locher Interests I Harza Northwest /ISER report of 1998 recommended a 500 kW project using an average pipe ID of 16". Voxland (Locher Interests report) recommended a 600 kW project. A 330 kW project using a 16 11 OD pipeline was recommended by Polarconsult (1995 Feasibility Study). ISO 9001 Pagel ~ WorkingTog~~~ ©Hatch 2011/07 ~HATCH .. Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report The purpose of analyzing various project si zes, all of which meet current demand requirements, is to determine an optimal project size that w o uld accommodate future load increases without constructing too much stranded capacity . This approach is adopted based on the assumption that the pipeline is not expandable. Due to the v ery long length of the pipeline, the remote location, and the complex topography it would be cost prohibitive to either replace the p i peline with a larger size or add a second pipeline alongside the original at some point in the future for marginal ga i ns in capacity. 2.2 Turbine Configu ration Initial an alysis focused on whether installation of the full project capacity in a si ngle or dual turbine configuration was preferable. Subsequent findings indicated tha t the cost of the p roject was quite high and that all reasona ble efforts should be made to rema i n economical. G iven tha t the present day peak demand in O ld H arbor is substantially less than the proposed project capacity, the analysis includes construction of partial capacity by plann ing for two turbines but installi ng on ly one of the units. Selectio n of the generation capacity was chosen on the basis of meeting current peal< demand (160 kW) plus 25% while maintaining identical generation units in any multiple turbine configuration. While the peak capacity of the pipeline is fixed, an add itional turbine and gene rator can be added easily if plan ned for. This approach all ows fo r • • • • Multiple Turbine Configurations A dual turbine installation allows for continuous operati on while performing inspection or maintenance on the other unit. Typi cal downtime for inspection is about one day a year and expected failures may result in a week offline A dual turbine configurati on as a base load project needs to synchronize 2 units. If a diesel is added to supplement the t urbines then there are 3 generators to control and synchronize adding to the complexity ofthe system . A single 680 kW turbine could operate with reasonable efficiency down to the m i ni mum flows. lower initial constr uction costs without sacrificing future capacity potential. Future c~sts and revenue associated with supplyi ng the add i tiona l turbine to meet fu ture l oa d growth is not included in the economic analysis. Although only one turbine is included in the cost estimate, tables an d charts depicting the amount of energy produced are based on the full project capacity with both tu rbines i nstalled . Th is app roach , explained in the previo us section, is based on comparing p roject potential as oppose d to proj ect utilization. Estimated project util ization, based on current demand, is the sa me rega rdl ess of project size. Tables and charts showing the cost of the project are based o n one of two turbines insta ll ed -7 ( when dual turbines are recommended . " The project capacity and generati o n ca pacity used in this report are d epicted graphica ll y in th e following chart. Details regarding the tu rbine configurations are included in the Cost Information section. ISO 9001 "\jjf:;/Workins~ ~ WO.Y Page3 c Hatch 2011/07 / 1000 900 800 700 i 600 ..¥ -~ 500 ·u a 400 Ill u 300 200 100 - 0 12 --Proj ect (Pipeline) Capacity -Installed (G eneration) Capacity 14 16 18 20 Pipeline Size (in) 22 24 Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Figure 1 -Project Capacity and Installed Capacity 3. 3.1 Cost Information Overview The physical layout of the project is based on the March 2010 project drawings found in the FERC e- library for the Old Harbor Hydroelectric Project (P-13272). Copies of the drawings are included in Appendix C. The overall approach taken in the development of this estimate is from a contractors construction perspective where quantities and pricing have been examined in detail. Also, the estimate has been prepared to reflect a traditional construction project and there is no attempt to reduce the total cost through value engineering methods or possible lower cost alternatives. This results in an estimate that should equate to the average to high range of responsive construction bids. Overall logistics for the construction involve shipping all materials from Seattle directly to Kodiak . . From there, materials would be unloaded from containers and shipped by landing craft barge to Old Harbor. Equipment will be shipped to and from Kodiak and remain on site for a 6 month period. As discussed above, no attempt has been made to reduce costs by optimizing equipment utilization and shipping schedules. The opinion of p robable cost (OPC) is based on the single season construction schedule in Appendix B. -- A number of different project sizes were evaluated as part of this cost estimate to facilitate the selection of pipeline size and turbine capacity for inclusion in the FERC license application. The comparison includes determination of potential annual energy generation, displaced diesel generation, and construction costs associated with each project size. The cost estimate accounts for changes in the project size by adjusting the following variables: • Pipeline material cost by weight. • Pipeline shipping cost to Kodiak by number of containers. • Pipeline staging cost along the alignment by helicopter placement. ISO 9001 Page 4 ~ WorldnsT~r Q W UY "Hatch 2011/07 ~HATCH™ Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report • Turbine and generator cost. Variables not subject to change in the OPC include pipeline installation and assembly cost. The reason being that trenching would probably be done in a single pass using a bucket sized for the pipeline resulting in negligible changes in excavation time. Also, fusing times for the HOPE are primarily based on setup times and thicknesses which do not vary much for the small sizes being considered. The steel pipe is assumed to be assembled by mechanical couplings that will require very nearly the same time to assemble for all the pipe sizes considered. Differences in the intake size, valves, powerhouse, transmission, and tailrace sizes are all considered too minor to evaluate for the low flow rates and power differences being considered and as a percentage of total project costs. 3.2 Schedule A schedule for the construction was developed to assist with the cost estimating. The construction window for work in the upper reaches of the project extends from about june through October. Equipment and labor were adjusted to ensure that production rates met this limitation. The intake and pipeline construction and the required intake access trail are the primary drivers for the schedule. The actual start of the project is set for the beginning of May. The date for material mobilization is based on a 4 month procurement window after license issuance for pipe and other materials (including the powerhouse) from Seattle. The schedule is included in Appendix B. Although not used in the OPC, a two season construction schedule is also included in Appendix B. 3.3 Equipment and shipping Mobilization is based on shipping all materials from Seattle to Kodiak. Samson quoted $5000/container although $6000 is used in the estimate. Equipment is expected to originate in Kodiak. Subsequent shipping of materials and equipment to Old Harbor is accomplished by landing craft. The landing craft is capable of handling loads of up to 80k pounds or up to an equivalent of 4 containers when stacked (containers must be unloaded). This estimate assumes that, on average, 2 containers can be shipped at once for material and that 5 trips each at the beginning and end of the project are required to haul equipment. Each trip with the landing craft to Old Harbor is $6000 (MN Lazy Bay) although the cost estimate uses $7500 to account for additional costs associated with unloading and dock fees. A helicopter quote was obtained from Maritime helicopters in Homer. Haul time is based on 40' pipe sections and load carrying capacity. In lieu of using a helicopter, track haulers (Marookas) could be used to haul pipe resulting in some potential savings. The adequacy of the access trail will dictate whether this is a viable option. The helicopter option has the potential to reduce the amount of shot rock used on the construction trail although this potential savings is not included in the estimate. Equipment rental rates listed in the estimate are based on published rental rates from Craig Taylor equipment and a quote from Brechan for the Marookas. Housing costs are estimated based on the rental of 4 houses for 6 months. Contractor air travel is based on 2 charters per month from Kodiak. ISO 9001 "0'<1:1' WorkingTo110ther v SAFE>¥ Page 5 Hatch 2011/07 ~HATCH ™ 3.4 Powerhouse Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Concrete material costs of $200/cyd are based on pricing of similar projects. The Old Harbor cost estimate includes 6 weeks of labor to construct the powerhouse. The building cost of $130/sq ft is based on past experience with building construction. This is likely higher than most industrial metal buildings but the building is also relatively small. A price quote for the crane was not obtained . The tailrace construction is based on creating a stream channel from the powerhouse to the pond and from the pond to the existing upper limit of the Lagoon Creek Tributary. Material costs are estimated based on a preliminary design ($21/ft). A culvert is included at the powerhouse to allow for vehicle travel over the tailrace. An earthen dike is also included to confine tailrace flows to the Lagoon Creek Tributary. In lieu of a constructed stream channel a 30" culvert ($30/ft) could be used to discharge tailrace waters into Lagoon Creek. 3.5 Turbine Cost Turbine and generator costs are based on a budgetary quote from Canyon Industries for a 500 kW unit with controls for standalone operatiqn. Other size turbines are based on separate price quotes ·and interpolation. Where dual turbines are considered, the cost includes only one of the turbines but adds an estimated bifurcation and equipment cost. The following table shows the price of the turbine and ·generator used in the cost estimate for various size projects. An additional $150k is included elsewhere for additional controls and integration with the existing diesel power plant. Switchgear price, not included in the turbine pricing, is fixed (independent of project output) and is estimated at $50k. Table 1-Turbine and Generator Price Schedule Project Turbine Installed Turbine Total Turbine Pipe Size Capacity Arrangement Capacity Package Piping/Ace Package Cost 12 172 Single 172 $350,000 $0 $350,000 14 266 Single 266 $460,000 $0 $460,000 16 381 Single 381 $570,000 $0 $570,000 18 525 Dual 262 $450,000 $40,000 $490,000 20 669 Dual 335 $530,000 $60,000 $590,000 22 821 Dual 410 $590,000 $83,000 $673,000 24 994 Dual 497 $670,000 $113,000 $783,000 3.6 Intake .The cost of the intake works is based on hauling premixed bags of aggregate and cement in using Marooka's and mixing on site using w~er from the creek and a 1/3 yard mobile mixer for construction of the concrete diversion structure. Additional work includes construction of a screeningldesander box with a trachrack, screens, and gates for filtering of the water. Concrete material pricing at the intake is doubled to account for the remote location. Other prices on the intake works are estimated based on past experience. A preliminary intake concept design with quantity estimates in included in Appendix C. ISO 9001 ~Workina~r 0 SNII.Y Page 6 . c Hatch 2011/07 Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report 3.4 Powerhouse Concrete material costs of $200/cyd are based on pricing of similar projects. The Old Harbor cost estimate includes 6 weeks of labor to construct the powerhouse. The building cost of $130/sq ft is based on past experience with building construction. This is likely higher than most industrial metal buildings but the building is also relatively small. A price quote for the crane was not obtained. The tailrace construction is based on creating a stream channel from the powerhouse to the pond and from the pond to the existing upper limit of the Lagoon Creek Tributary. Material costs are estimated based on a preliminary design ($21/ft). A culvert is included at the powerhouse to allow for vehicle travel over the tailrace. An earthen dike is also included to confine tailrace flows to the Lagoon Creek Tributary. In lieu of a constructed stream channel a 30" culvert ($30/ft) could be used to discharge tailrace waters into Lagoon Creek. 3.5 Turbine Cost Turbine and generator costs are based on a budgetary quote from Canyon Industries for a 500 kW unit with controls for standalone operation. Other size turbines are based on separate price quotes and interpolation. Where dual turbines are considered, the cost includes only one of the turbines but adds an estimated bifurcation and equipment cost. The following table shows the price of the turbine and generator used in the cost estimate for various size projects. An additional $150k is included elsewhere for additional controls and integration with the existing diesel power plant. Switchgear price, not included in the turbine pricing, is fixed (independent of project output) and is estimated at $50k. Table 1 -Turbine and Generator Price Schedule Project Turbine Installed Turbine Total Turbine Pipe Size Capacity Arrangement Capacity Package Piping/Ace Package Cost 12 172 Single 172 $350,000 $0 $350,000 14 266 Single 266 $460,000 $0 $460,000 16 381 Single 381 $570,000 $0 $570,000 18 525 Dual 262 $450,000 $40,000 $490,000 20 669 Dual 335 $530,000 $60,000 $590,000 22 821 Dual 410 $590,000 $83,000 $673,000 24 994 Dual 497 $670,000 $113,000 $783,000 3.6 Intake The cost of the intake works is based on hauling premixed bags of aggregate and cement in using Marooka's and mixing on site using water from the creek and a 1/3 yard mobile mixer for construction of the concrete diversion structure. Additional work includes construction of a screening/desander box with a trachrack, screens, and gates for filtering of the water. Concrete material pricing at the intake is doubled to account for the remote location. Other prices on the intake works are estimated based on past experience. A preliminary intake concept design with quantity estimates in included in Appendix C. ISO 9001 'V57 WorkingTogether ~ SAfElY Page 6 ~Hatch 2011/07 Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Communication to the intake is required to transmit head level information to the turbine controller. Additional data channels, including IP data connectivity, are desirable for monitoring purposes. The cost estimate includes pricing of a direct bury 4 pair communications cable. The estimate also includes price information based on budgetary quote for a direct bury aluminum conductor and two 15 kVA single phase transformers to provide power to the intake. 3.7 Pipeline Pipeline material costs were quoted on a budgetary per pound basis. This facilitated cost estimation of different project sizes. HOPE cost was quoted $1.00/pound by ISCO pipe with a projected increase in the near future of about 10%. The cost estimate uses $1.20/pound. The estimated rental rate of the fusion machine in the OPC is very close to the quoted purchase cost of a new 20" tracstar machine. The option of supplying HOPE in Seattle with flanged ends and ductile iron backing rings fused onto the pipe by the factory was considered. An analysis of the labor and equipment savings associated with elimination of the fusion machine indicates a small potential savings for the smallest pipe sizes (12 and 14) only. Steel pipe was quoted by Northwest at $1.25/pound coated. The estimate uses $1.50/pound based on expected near term price increases. Steel pipe coupling prices are based on using Victaulic painted style 77 couplers. The coupler prices for each pipe size adjust accordingly. Although not suitable for all of the joints in the steel pipe, the cost per coupling should approximate welded alternatives. Other pipeline material costs are estimated including thrust and restraint anchors. The cost estimate assumes installing rock anchors at each bend. A total of 50 anchors, 3 minor thrust blocks, and a major thrust block near the powerhouse are estimated. Labor cost for the construction of the pipeline, after completion of the trail, is based on a production rate of 20' per hour. 3.8 Transmission and Roads The access trail to the intake represents a significant portion of the construction cost for the project. The quality of the trail affects the productivity of hauling materials and laborers to the work site and impacts pipeline installation. Without a stabilized trail, erosion becomes a problem during construction and future maintenance is negatively impacted. Construction methods can be employed that can reduce the effort put into the trail. With placement of materials by helicopter and mechanical pipe joints the level of effort put into the trail may be lessened. Such decisions are more appropriately addressed during the design and construction phase and, to remain somewhat conservative, the construction of a fully stabilized trail is incorporated into the cost estimate. A preliminary concept drawing for the trail is included in Appendix C. Costs for the pipeline access trail include a quoted, all inclusive cost for shot rock from Brechan Enterprises in Kodiak, developed and staged at the pit near the water tank (beginning of project) of $15 per cubic yard (Brechan developed the pit and constructed the water tank access road in 2010). Volume of shot rock is based on a 12' wide trail with 2' of fill. Other estimated costs for the access trail include geo-textile filter fabric and soil stabilization over the entire length, culverts, and an access gate. Labor is based on a production rate for three Marooka track haulers capable of hauling a 5 yard load at a speed of 2.5 mph up and 5 mph down. Rock excavation in the upper portions of the access trail, particularly in the section near the intake, represents a potential material savings that is ISO 9001 ~ WorkinglOII!ther v SM£i.Y Page 7 Hatch 2011/07 ~ HATCH TM Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report not included in the estimate. An additional 2 weeks is budgeted for culvert installation and erosion control. As with the pipeline trail, the powerhouse access road is based on a fill over fabric on existing grade. Width is 24' and depth of 1.5' of shot rock and 6" of crushed rock. The cost estimate uses the Brechan quote of $25 per cubic yard for using a crusher brought to the site. labor production rate for the road is estimated at about 40' per hour. Overhead transmission line costs are estimated and equate to about $140,000 per mile. 3.9 Indirect Costs Overhead costs include a mix of percentages applied to the direct construction costs and flat fees. It is assumed that the owner will procure the turbine, generator, and controls work directly. Indirect construction costs include the fol lowing: Table 2-Ind irect Costs Indirect construction costs Weather delay contingency contractor profit bonding Indirect Qroject costs construction interest engineering inspection and testing owner admin ISO 9001 Rate 5% 15% 15% 2% Rate 2.25% Flat fee Flat fee Flat fee Note Applied to labor and Equipment Cost High level of detail in estimate warrants a lower contingency Standard profit margin for construction contract Performance bond and other Insurance Note Finance half the cost of constructi on at a 9% rate for 6 months Fees for design and procurement documents Fees for asbuilts, O&M manuals, and startup costs Owner supervision, inspection, and training Page 8 ~ WorltingTo~her V' SNUY e Hatch 2011/07 4. Power Study 4.1 Methodology Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report The model created to evaluate the costs an d selection of the hydroelectric project requires an evaluation of the hydrology and calc ulating performance for each configuration of the hydroelectric project. Modeling is based on daily values although daily fluctuations in demand are included as well in the benefit analysis. The following sections describe the details of the model development and results . 4.2 Old Harbor Demand Demand growth is expected to remai n flat (based on historical trends). AVEC provided 2010 load information consisting of monthly su mmari es and 15 minute average kW readings. The monthly summary data shows that total energy prod uction with diesel in 2010 was approximately 810,000 kWh with a peak load of 160 kW. Th e primary generator in Old Harbor is a 1,200 rpm electronic fuel injected Detroit diesel. Installed in 2005, this unit is designed to operate efficiently over a wide range and at low load. Older mechan ically injected Caterpillar units provide backup. AVEC also provided 15 minute avera ge da ta for 12/26/2009 through 12/29/2010. Data was missing from 3/6/2010-3/27/2010 and 12/1/2 010-12/8/2010. The missing data was filled in by copying data from other dates with sim i lar loads. With a complete data set a daily average load profile was calculated to determine the magnitude an d duration of peak demand in comparison to average daily demand. Differences in the monthly summari es and 15 minute data were minor except monthly peak loads in the 15 minute data set are about 93 % of th ose reported in the monthly summary. This is likely due to instantaneous peaks occurring within th e 15 minute intervals. Modeling of displaced diesel to dete rmi ne the potential benefit gained from the hydro project i nvolved determining how much diesel us age would occur during hydro operation. The model assumes a diesel must come online before the demand actually meets the hydro output and the diesel will run at a specified minimum load for a minimum amount of time. Using the 15 minute data set, if the daily peak demand exceed ed 90% of the hydro output then the model assumes that a diesel generator will be started and run at no less than 10% load for at least the number of peak hours in the day, which is about 16 based on the daily load fluctuation. AVEC reports that the diesel generators installed in Old Harbor are 235 kW. The following table compares the monthly and 15 minute demand data provided by AVEC w hile the following figure shows the daily load profile in Old Harbor using the 15 minute de mand data . ISO 9001 Page 9 o Hatch 20 11/07 ~HATCH ™ j T bl 3 Old H b D d S a e -ar or em an ummary Old Harbor Monthly Demand Summary (kW, kWh, gal) . Month Generation Peak Average Jan-10 72,592 146 98 Feb-10 63,784 142 95 Mar-10 70,261 145 94 Apr-1 0 65,624 140 91 May-10 66,398 135 89 jun-1 0 61,534 133 85 jul-1 0 64,689 145 87 Aug-10 70,255 147 94 Sep-1 0 70,768 160 98 Oct-10 64,466 140 87 Nov-10 66,371 149 92 Dec-10 70,474 147 95 Fuel 5,238 4,573 4,995 4,754 4,623 4,476 4,627 4,990 5,026 4,715 4,766 5,072 Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report 15 Minute Demand Data Peak Average 140 96 138 95 132 92 131 91 127 89 124 85 127 87 137 94 147 98 127 87 138 92 133 94 Total 807,216 160 92 57,855 150 , .. .. 140 , .. -weekday ... 130 .. --weekend .. §' .. - --peak .. .:.:: 120 .. -, .. c 110 .. ns E , Gl 100 -. c .. ---- Gl 90 0') ns .. Gl 80 > ct 70 60 50 0 2 3 4 5 6 7 8 9 10 11 12 13 Hour of Day Figure 3 -Old Harbor Average Daily Demand Fluctuations ISO 9001 ~WorldnaT~ ~ WU.T .. , .. -.. .. ,. , " --, , , , 14 15 16 17 18 19 20 21 22 23 Page 10 c Hatch 2011/07 4.3 Hydrology Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report The hydrology data used for the analysis is the median of the daily flow values for the East Fork of Mountain Creek published in the Mountain Creek Hydrology Report (Polarconsult, May 4, 201 0). The report analyzes about 5 years of stream flow data measured from 7/14/1993 through 5/6/1996 (Alaska Department of Natural Resources) and from 6/15/1998 through 8/16/2000 (Polarconsult). The report compares the data with Kodiak rainfall and other USGS gauged streams. After comparison with USGS data, the report recommended adjustment factors be applied to the measured hydrology data based on a comparative analysis to the other gauge sites on Kodiak Island. The report also found flow measurements on Mountain Creek occurred during wetter (by about 20°/o) than normal rainfall years in Kodiak, AK. Based on those findings, this analysis uses the recommended adjustment factors with at least a 20% reduction in the summer and fall to account for the higher than normal precipitation. As stated in the May 2010 report, the conservative adjustments applied to the measured data can be adopted in lieu of performing additional flow measurements to confirm winter and spring low flows. The resulting adjusted hydrology data set is on par with a predicted hydrograph for Old Harbor in the absence of flow measurement data. However, it should be noted that real differences may exist between the Mountain Creek basin and the comparison basins as well as in the precipitation for Old Harbor compared with Kodiak. Such differences may prove that the 5 years of measured data on Mountain Creek is more representative of the long term average. For comparison purposes, this report presents an alternative analysis that does not use the adjustment factors. It is noted that the amount of useable energy from the hydroelectric development varies very little with either data set. The rationale for presenting an analysis using the measured data (unadjusted) as well as the adjusted data is in the event that excess energy utilization is considered. Given that the selection of project size is based on the presumption of additional energy utilization at some point, the unadjusted hydrology may assist in evaluating how much excess capacity would be available and the timing of such capacity. The accompanying charts show the hydrograph and flow duration curve for each hydrology scenario. The power potential axis on the hydrograph does not include the effects of changes in the dynamic head and efficiency of the turbine. The power production model discussed in the next section does include those dynamic variables as well as specific pipeline parameters for each alternative project co nfi gu ration. ISO 9001 'VCl' Workinglogl!ther v SAfU.Y Page 11 © Hatch 2011/07 ~ HATCH™ a e -IJUS men T bl 4 Ad' t ac ors or tF t f M easure d St Month 1 2 3 4 Adjustment 57% 56% 61% 74% 20.0 18.0 16.0 14.0 - :[ 12.0 ~ 0 10.0 I;: E IU 8.0 G) ... -(/) 6.0 4.0 2.0 0.0 1/1 2/1 311 4/1 5/1 6/1 ream Fl tl t k n a e owsa 5 6 7 80% 80% 80% 7/1 8/1 9/1 Date 8 Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report 9 10 11 12 68% 50% 55% 69% 53% 1000 900 800 i ::. ii 700 :;::::: 1: 41 -600 0 ll.. 1.. 41 500 ~ 0 ll.. 400 41 ~ 300 E ·;::c 0 1.. 200 c. c. ~ 100 0 10/1 11/1 12/1 Figure 4 -Old Harbor Project Hydrograph and Approximate Power Potential 30 -Median Unadjusted Flow 25 --Median Adjusted Flow ;E'20 (.) -G) ~ 15 IU ~ (.) .!!! 10 c 5 0 Oo/o 10% 20% 30% 40% 50% 60% 70% 80% Percentage of Time Discharge Equaled or Exceeded Figure 5-Flow Duration Curve for the East Fork of Mountain Creek ISO 9001 ~ WorkingT~r 0 SNEI.Y 90% 100% Page 12 <> Hatch 2011107 ~ HATCH™ Old Harbor Hydroe lectric Project Reconnai ssance and Feasibility Study Final Report 4.4 Power Production Power production is based on using both sets of daily hydrology data, above, and the various pipeline sizes and corresponding flow rates under consideration. Hydropower is then calculated daily taking into consideration friction , minor losse s, and turbine efficiency at the given flow rate . Pipe diameter and thickness selection is based on the static pressure of the project with peak flow rates determined by constraining velocity in the pipeline to about 8 .5 feet per second and limiting head loss to 15%. A nominal pipeline size of 18" results in the following selected pipe diameters and thicknesses along the project alignment. The increased pipe size in the first section of the project is required to prevent vacuum conditions during operation . Alternative size scenario s follow a similar pattern in pipe selection. a e -1pe e ec 10n T bl 5 p· S I f AI ong roJeC 1gnmen P . t AI" t Start End Station End Static PipeOD Type Min SDR Se lected Th ic kness Pipe 10 Station Elevation Press ure SDR 0 1100 2200 3000 3500 4100 4500 5000 5500 6100 6500 7000 7500 7700 9500 ISO 9001 1100 845 2 20 PE3608 3 2 .5 2 6 0 .769 18.46 2200 835 6 2 0 PE3608 3 2.5 26 0 .769 18.46 3000 805 19 18 PE3608 32 .5 26 0 .692 16.62 3500 730 52 18 PE3608 26 .0 26 0 .692 16.62 4100 630 95 18 PE4710 21 .0 21 0.8 5 7 16.29 4500 585 115 18 PE4710 17.0 17 1.059 15 .88 5000 540 134 18 PE4 7 10 15.5 15.5 1.161 15 .68 5500 520 143 18 PE4710 13 .5 13 .5 1.333 15.33 6100 480 160 18 PE4710 13.5 13 .5 1.3 3 3 15.33 6500 495 154 18 PE4710 13 .5 13 .5 1.3 33 15.33 7000 525 141 18 PE4710 13.5 13.5 1.333 15.33 7500 505 14 9 18 PE4710 13 .5 13.5 1.3 33 15.33 7700 475 162 18 PE4710 11.0 11 1.636 14.73 9500 275 249 16 st e el 134 .2 128 0 .125 15.75 10350 85 331 16 ste el 100.8 64 0 .250 15.50 Minor losses du e to screens , valves, and bend s are calculated in addition to the pipeline friction losses . The total minor loss factor, K, is 6 .55 . Other inefficiencies in the production of power include transformer and line losses of 2%, generator efficiency of 95%, and turbine peak efficiency of 89%. All of the scenarios ignore the potential gain in efficiency using dual turbines and are based on a single turbine operating at all times . Varying of efficiency versus flow rate is included in the analysis using the efficie ncy fac tors shown in t he tabl e . Shut o ff load for a si ngl e turbine i s ~ss u me d to be 10 % o f rated capaci ~. Th e minimum flow at the intake is 2 cfs so multiple turbine configuration s are not requ ired to m ain ta in year round operation for the project sizes analyzed. The following table shows the detail s of each project size evaluated. Turbine nameplate capacity will be slightly higher than the values in the table. ...,..., Work i ngTogether V SAFHY %Power 10% 20% 30% 40% 50% 90% 100% Turbine Efficiency 63% 78% 85% 87% 89% 89% 8 7% Pa ge 13 <>Hatch 2011/07 T bl 6 p· o· a e -1pe 1ameters, Fl ows, Base Pipe Flow Rate (cfs) Diameter (in) 12 3.9 14 6.0 16 8 .5 18 11.8 20 14.8 22 17.8 24 21.3 L osses, an dP ower Headloss (ft) 115 115 115 115 105 92 84 0 utput Peak Output (kW) 172 266 381 525 669 821 994 Old Harbor Hydroelectric Project Reconnaissance and Feasi bi I ity Study Final Report Conversion to potential energy includes evaluation of the dynamic head at each flow rate and the interpolation of turbine efficiency. Using the daily median flow values for the East Fork of Mountain Creek the following chart shows the annual potential energy output for various project sizes. 4,500 -Adjusted Output. k\l\lh 4,000 -Unadjusted Output. k\l\lh ~ 3 .500 ~ >. C) (j; c: 3,000 w -ro :J c: c: <( 2,500 Plant Plant Fador, Plant Factor, Capacity Adjusted Unadjusted 172 91% 99% 266 81% 92% 381 70% 84% 2 ,000 525 60% 76% 669 53% 68% 821 46% 62% 990 41% 55% 1,500 200 300 400 500 600 700 800 Project Capacity (kW) Figure 6 -Old Harbor Hydro Annual Energy Potential 4.5 Project Selection The 2010 annual energy demand in Old Harbor was approximately 810 MWh with a peak demand of 160 kW. All of the project sizes under consideration are able to offset about the same amount of ISO 9001 'V':J WorkingTo!rlllher V SAfElY Page 14 ©Hatch 2011 /07 ~HATCH ™ --Ill 0 Co) ... ~ ·c:; c. IG ~ -N < ~ ~ Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report diesel generation and provide about the same net benefit. Except for the smallest project considered, the alternatives include a significant amount of stranded plant. In lieu of determining how much of the surpl us energy may be utilized, a simple unconstrained approa~h to selecting a project size is adopted that maximizes annual energy production with the least amount of initial cost and capacity. 7 For the purpose of selecting a project, all the energy produced by the various confi g uratio rlsis ~ ; assumed to have the same value. From this assumption, a relationship chosen to optimize the resource is to maximize the ratio of total energy produced per unit capacity to the cost per unit energy. This relationship is represented as kWhA2 I (capacity * cost). When this is done, as seen in the following chart, the adjusted hydrology data produces a flat area l representing a range of projects that provide the best economic return with the 16" p i peline (381 ~ kW) project being optimal. The optimal project for the unadjusted hydrology data utilizes an 18" ~ ~ pipeline (525 kW). The OPC provided with this report is for the 525 kW project which utilizes an 18" pipeline and approximately 11.8 cfs of flow. 3,000 2,800 2.600 2,400 2.200 2.000 1.800 1.600 1.400 1,200 1,000 100 200 ' ~Adjusted Hydrology ~Unadjusted Hydrology 300 400 500 600 Project Capacity (kW) 700 800 900 Figure 7 -Project Optimization Chart ISO 9001 Constructability aspects such as fusion machine capabilities (20" being a breakpoint) and the numerous bends favor the smaller range of pipe diameters whereas, operationally, the larger pipe diameters are preferable to reduce the dynamic pressure range at the turbine. Overall, the optimum project of 525 kW is reasonable from both an operational and constructability viewpoint. Page 15 c Hatch 201 1/07 5. Results 5.1 Cost Comparison Old Harbor Hydroelectri c Project Reconnaissance and Feasibility Study Final Report Total cost of construction, including indirect costs, for all the project configurations are presented below . T bl 7 P . t Alt a e -roJeC f c erna 1ves ompanson Pipe Size Installed Potential Installed Cost Potential % Increase in % Increase in Capacity, kW Capacity, kW Energy, kWh Potential Energy Installed Cost 12 172 172 $7,270,000 1,500,000 0 % 0% 14 266 266 $7,5 10,000 2,150,000 43% 3% 16 381 381 $7,860,000 2,800,000 87% 8% 18 262 525 $7,9 70,000 3,470,000 131% 10% 20 335 669 $8,430,000 4 ,000,000 167% 16 % 22 410 821 $8 ,780,000 4,430,000 195 % 21 % 24 497 994 $9,140,000 4,800,000 220% 26% It is evident from the table above that there is a large amount of fixed costs that are independent of project size. A relatively small incremental cost increase of 10% is associated with a more than doubling (131% increase ) of the potential annual energy output. The cost of meeting Old Harbor ba se load requirements (160 kW) with the h~dro project are relati ~el 't highJ' but the co;;j 9f ?btainin ~ 11 . surplus energy is very low.-.....,. ltv'~ ,.,,[j ~ 1£. ~I tf~t~T~ ~ 'f'kn tf ~~ 5.2 Cost Detail The table below summariz es the OPC for the H ydroelectric Project. A more detailed estimate is included in Appendix A. T bl 8 0 .. • f p b bl c t s 525 kW P . t "th 50°!. I t II d C • Item Labor Labor Cost Equip Cost Materials Cost Hours PRECON STRUCTION AND CONSTRUCTION SU PPORT !MOBILIZATION POWERHOUSE INTAKE PIPELINE !ACCESS TRAIL iJURBINE AND GENERATOR INSTALLATION ROADS , TAILRACE jrRANSMISSION EQUIPMENT ~UBTOT Al, Contractor Direct Costs 18,218 $ 1,495,017 $ 644,900 $ 1,814,562 !Weath e r delay (% of l abor and Equip) ronti ngency !contractor profi t bondin g ~UBTOTAL , Construction Contract SUBTOTAL, Owner Procurement, Turbine and Generator ISO 9001 'V"/ WorkingTogether ~ WILY 5% 15% 15% 2% Ship Cost $ 557,100 Total Cost $ 444,450 $ 423,000 $ 349,041 $ 4 33,007 $ 981,278 $ 465 ,039 $ 166,300 $ 425,889 $ 208,6 75 $ 6 14 ,900 $ 4,511,579 $ 106,996 $ 676,737 $ 676,737 $ 90 ,232 $ 6,062 ,280 $ 640,000 Pa ge 16 <>Hatch 201 1/07 ~ HATCH TM Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Item Hlabor labor Cost Equip Cost Materials Cost Ship Cost 1 Total Cost ours SUBTOTAL , Const ru ction ~onstruction finance interest ~ngineering ·nspection and test i ng owneradmin TOTAL PROJECT 5.3 Project Benefits 10% 3% 4% $ 6,702,280 $ 150,80 1 $ 649,400 ~----~ $ 2 1 7,2 00 $ 250 000 $ 7,969,681 Calculation of the potential benefit gained from the hydro project involved determining how much diesel usage would occur during hydro operation. The unadjusted hydrology data set results in no diesel makeup energy required (the hydro would meet 100% of the existing demand requirement). The tab.le below shows summarizes the project benefits . · Table 9-Annual Fuel Savings with Hydro Project Existing Annual Generation 807,216 kWh Existing Annual Fuel Use 57,855 gal Fuel Price ~\ 4.08 $/gal Existing Ann uall xp enditures $235,911 Annual Diesel Generation with Hydro Fuel Used Cost Annual Fuel Savings with Hydro Project Displaced Diesel Fueled Generation Adjusted Hydrology 34 ,852 3,168 $12,919 $222,992 95% Unadjusted Hydrology 0 kWh 0 gal $0 $235,911 100% Old Harbor's fuel consumption for diesel elect ric generatio~ 2010 was 57,855 gallons. The hydroelectric project would reduce fuel use by 'l.!.!_east 95%. A ll of the project configurations analyzed result in the same benefit with regard to o ffs etting existing diesel generation. The high availability of the hydro project results in a significant amount of stra nd ed plant. Evaluating pos sib le / uses and econ omic values of the surp l us energy fro m th e hydro wil l add to t he overall economi c/ benefit. The following charts, one for each hydrology scenario, show the expected daily potential hydro output and the expected amount of diesel generation with the hydro to meet current demand using the 525 kW hydro project. ISO 9001 Page 17 «> Hatch 201 1/07 ~HATCH .. 600 500 400 ~ ::. 300 ... G) :.t 0 11.. 200 100 0 -Turblne2 Turbine 1 -Diesel w / Hydro -------Exist Diesel , Avg -Exist Diesel. P~ak --Total Hydro Output I DayofYear Old Harbor Hydroelectri c Project Reconnaissance and Feasib i lity Study Fi nal Repo rt Figure 8-Hydro Output (Adjusted Hydrology Data) and Diesel Generation Requirements 600 500 400 ~ ::. 300 ... G) :.t 0 11.. 200 100 0 -Turblne2 Turbine 1 -Diesel w/ Hydro -------Exist Diesel . Avg -Exist Diesel. Peak DayofYear Figure 9-Hydro Output (Unadjusted Hydrology Data) and Diesel Generation Requirements ISO 9001 ~ WorldngTaJ!l her ~ SNflY Page 18 "Hatc h 2011 /07 ~HATCH ~ 6. Economic Analysis 6.1 Diesellntegration Old Harbor Hydroelectric Proj ect Reconnaissance and Feasibility Study Final Report As shown in Table 8, the expected annual fuel savings from the hydro project ranges from $222,992 to $235,911 depending on the actual hydrology. If the past hydrology measurements prove to be correct then the hydro project will displace about 100% of the current diesel generation. If the past hydrology measurements over represented actual runoff, then the amount of diesel generation displaced is expected to drop to about 95%. Because the hydro project and diesel plant may operate simultaneously at times, the amount of displaced diesel generation also depends on the configuration of the existing system. The smallest generator in the Old Harbor power p lant is 2 35 kW. Using the adjusted hydrology set, the typical minimum output of the hydro project in the winter is about 90 kW. This i s enough power to meet Old Harbor's average load but not the peak loads. Therefore a diesel generator must come online during the peak loading times to supply, on average, about an e xtra 2 2 kW. Under this scena rio, the 235 kW diesel generator is operating at the desired minimum load rating o f 10%. Efficiency at this low load is estimated to be 11 kWh/gal. 6.2 Economic inputs Operation and maintenance (O&M) costs can become a large part of the project economics over the long term. Several factors to consider include diesel engine repair and replacement, oil changes, hydro intake cleaning, repair, maintenance, and complying with the additional permitting requirements of the hydro project. Data for non fuel expenses related to diesel generation was obtained from AVEC PCE Annual Reports for the years 2008 through 201 0 filed with the Regulatory Commission of Alaska. The reports include non fuel expenses for the entire AVEC system and therefore should be representative o f ann ualized costs . Over the course of 2008-201 0 the non fuel costs ranged from 0.096 $/kWh to 0.117 $/kWh with an average of 0.107 $/kWh. The cost are divided among 26 different accounts and a reduction factor was applied to each account to calculate reduced diesel non fuel expenses . Reduction factors ranged from 0% to 90% with the weigh t ed average equal to 52%. The resulting non fuel cost for diesel with the hydro in operation is 0.056 $/kWh. O&M costs for the hydro project are estimated based on annualized costs and include 1.5% of the turbine cost for parts, $15,000 for FERC compliance and reporting, and $5,400 in m iscellaneous engineering and permitting support. Labor associated with operating the hydro p lant i s accounted for in the existing diesel non fuel category by partial reduction of daily checks and other maintenance. A study by the University of Alaska Anchorage ISER in 2011 projects real fuel prices for 2011-2030 in individual communities in Alaska . The projected prices are in 2010 dollars and range from $4.08/gal in 2014 to $5 .32/gal in 2030. For this analysis, the fuel price projection is extended to $5.52/gal in 2040 and flat from there on. ISO 9001 Page 19 ~Workins~~ <>H atc h 201 1/07 Old Harbor Hydroelectric Project Reconnaissanc e and Feasibility Study Final Report Like other major infrastructure projects, the hydro project has a very long project life . The project's economic life is assumed to be 50 years and all values are discounted to present day dollars using a 3% rate. The following tables summarize the economic inputs and first year results. Table 10-Economic Parameters Diesel Costs Fuel Price in 2014, First Year of Hydro ($/gal) 4.08 kWh Energy Generated, 2010 807,216 Fuel Used (gal) 57,855 Efficiency (kWh/gal ) 13.95 V\nnual Fuel Cost $235,911 O&M rate ($/kWh ) 0.10659 Current Annual O&M Costs $86,041 lfotal Diesel Annual Operational Cost, 2014 $321,952 H~dro Costs Initial Construction Co st $7,9 70,000 FERC Compliance and Reporting $15 ,000 Hydro O&M Cost ( f1 Annual Parts (1 .5% of turbine cost) P ,35 0 Labor (already inlcuded in Diesel non fuel ) $0 ~ Engineering (1 weeks/yr@ $135/hr) $5 ,40 0 t Diesel O&M rate with Hydro ($/kWh ) 0.05575 Diesel O&M Costs with Hydro $45 ,002 ~ lfotal Annual O&M Costs with Hydro $72,752 Annual Diesel Usage with Hydro (gal) 3,168 Annual Fuel Cost with Hydro $12 ,919 V\nnual Displaced Diesel Fuel 54 ,687 V\nnual Fuel Saving s $222 ,992 lcombined Hydro and Diesel Annual Operational Cost $85,6721 ~nnual Savings with Hydro $236,2811 6.3 Economic Results Using the simplest economic analy si s, the cost of the project divided by the annual savings provide s a simple payback period. Us i ng the total project co st, the annual savings re sults in a simple payback period of about 35 years . ISO 9001 Page 20 "Hatch 20 11/07 Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Using a more detailed analysis, where costs are calculated annually and then discounted, results in a benefit to cost ratio ranging from 0.94 to 1.00. The results of the detailed economic analysis are summarized below. Table 11 -Economic Summary Net Present Value (NPV) of Electrical Generation Costs Using Existing Using Hydro with Exist Diesel Diesel (Base) Adjusted Unadjusted Hydrology Hydrology Fuel $7,596,754 $416,023 $0 O&M $2,213,819 $1,871,899 $1,871,899 Total $9,810,573 $2,287,922 $1,871,899 Benefit $C $7,522,651 $7,938,673 Capital Cost $0 $7,970,000 $7,970,000 Ratio 0.94 1.00 6.4 Sensitivity Analysis A sensitivity analysis of changes to the benefit to cost ratio due to varying demand and construction cost has been performed using the projected fuel prices, discount rate, and term above. The table below shows the Benefit to Cost Ratio (NPV Savings I Initial Cost) for various percent changes in the demand (applied to both the average and peak) and the construction cost. The sensitivity analysis is based on using the hydro with a new diesel and the adjusted hydrology. Table 12-Benefit to Cost Ratio Sensitivity Analysis 0.93 -10% -5% -10% 0.9 1.0 -5% 0.9 0.9 ..... <fl 0% 0.8 0.9 0 u c 5% 0.8 0.8 (I) 10% 0.8 0.8 c.o c n:l 15% 0.7 0.8 ..c u ,;: 0 20% 0.7 0.7 25% 0.7 0.7 30% 0.6 0.7 ISO 9001 %change in demand 0% 5% 1.0 1 .1 1.0 1.0 0 .9 1.0 0.9 0.9 0.8 0.9 0.8 0.8 0.8 0.8 0.7 0.8 0.7 0.7 ~ Workinglogether V SIJHY 10% 15% 1 . 1 1.2 1 . 1 1 .1 1.0 1.0 1.0 1.0 0.9 1.0 0.9 0.9 0.8 0.9 0.8 0.8 0.8 0.8 20% 25% 30% 1.2 1.2 1.3 1.1 1.2 1.2 1 . 1 1 . 1 1.2 1.0 1 . 1 1 . 1 1.0 1.0 1 . 1 0.9 1.0 1.0 0.9 0.9 1.0 0.9 0.9 0.9 0.8 0.9 0.9 Page 21 "'Hatch 2011/07 7. Conclusions and Recommendations 7.1 Conclusions Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report The Old Harbor Hydroelectric Project has been investigated numerous times over the last two decades and has been actively pursued to the point of having a FERC license issued. A recurring result of the past work has been the high cost of the project as compared with the alternative of diesel generation. This investigation demonstrates that the project is still on the margin of being economical. However, the recognition of the secondary benefits and added security of locally generated energy weigh favorably for the hydro project and, while difficult to put into economic terms, are considered worthy of some additional cost. It is concluded that the Old Harbor Hydroelectric Project will prove to be a positive asset for the community and meet nearly all of the communities energy needs at a fixed cost. Once constructed, the benefits of the project will accrue for the indefinite future, and with the capacity to support additional growth, the project will result in a significant reduction in the cost of electrical energy generation in Old Harbor. 7.2 Recommendations The following recommendations are made: 1. Proceed with a project size using an 18" pipeline and a dual turbine configuration with only one 262 kW unit installed (50% of projects 525 kW capacity). An updated project description and analysis of environmental flows is included in Appendix D. 2. The near term demand growth can have a significant impact on the economics. It can also be an important consideration in selection of project size. Investigate the possible uses of surplus energy taking into consideration the timing of use. Revise project size recommendation as appropriate. 3. Continue with project development with a focus on obtaining financing, completing FERC licensing and permitting with the goal of minimizing post construction annual expenses, and proceeding with final design work for timely construction readiness. ISO 9001 ";zt;::' WorklngTog~~ther v wnv Page 22 Hatch 2C11/07 ~HATCH .. Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report 8. References Alaska Energy Authority, Alaska Energy Pathway 201 q. ftp://ftp.aidea.org/201 OAiaskaEnergyPian/201 OAiaska~nergyReport.html Alaska Village Electric Cooperative, PCE Annual Repdrts for 2008, 2009, and 2010. Regulatory Commission of Alaska. ISO 9001 Federal Energy Regulatory Commission, Final Envirorlmental Assessment, Old Harbor Project P- 11690, june 26 2000. http://elibrary.ferc.gov:O/idmWs/file list.asp?document id = 3105779 Federal Energy Regulatory Commission, Order issuing original license re Alaska Village Electric Cooperative's Old Harbor Hydroelectric P-11690, D~ember 12 2000. http://elibrary.ferc.gov:O/idmwslflle list.asp?document id = 2109984 I Locher Interests LTD (with Harza Northwest and UM ISER), Rural Hydroelectric Assessment and Development Study: Phase II Report, March 27, 1996, ADCRA Division of Energy. Polarconsult Alaska, Inc., Mountain Creek Hydrology Report, prepared for Alaska Village Electric Cooperative Inc., May 4,·201 0. http://el i brary. ferc.gov/idmwslcommon/Open Nat.asprfi lei D = 1 23 3 9 7 41 Polarconsult Alaska, Inc., Project Maps, Prepared for Alaska Village Electric Cooperative, March 2 2010. http://elibrary.ferc.gov:O/idmws/file list.asp?document id = 13800685 Polarconsult Alaska, Inc., Notice of Intent and Preli~inary Application Document under P-13272, August 21 2009. http://elibrary.ferc.gov:O/idmwslfile: list.asp?document id-13748178 Solstice Alaska Consu lting Inc., Proposed Study Plan, Old Harbor Hydroelectric Project, FERC Project P-13272, prepared for Alaska Village Electric Cooperative, january 4, 2010. http://elibrary.ferc.gov/idmws/common/OpenNat.asp?fi lei D = 123 39737 State of Alaska, Alaska Division of Community and Regional Affairs, Community Information Summa ri es, 2011. http://www.commerce .state.ak.u~dca/commdb/CF CIS.htm University of Alaska Anchorage, Institute of Social and Economic Research (ISER), Alaska Fuel Price Projections 2011-2030, January 25, 2011. US Department of Labor, Bureau of Labor Statistics, Consumer Price Index, Fuel Oil, US City Average, Series ID CUSROOOOSEHE01. Page 23 c Hatch 2011/07 ~HATCH™ Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Appendix A-Opinion of Probable Cost-525 kW Project with 50°/o Installed Capacity ISO 9001 Page A-1 <> Hotch 2011/07 Old Harbor Hydroelectric Project Estimated Construction Cost Base Labor Rate I hour Super and specialist Work week Item PREg)~~TR!,!QIQ~ A~~ !;QN~TR!,!QIQ~ ~!,!PPQRT Procurement, Submittals I SWPP Survey Planning Construction Support Asbuilt Mechanic Hou si ng, Travel labor housing contractor travel MQBILIWIQN Equipment transport landing barge to Old Harbor Operator Laborer Materials Shipping Pipe Jet Fuel Building Concrete Diversion Power Poles Wire and Electrical Turbine and Generator Transformer, Switchgear landing barge to Old Harbor Demob Equipment landing barge to Old Harbor Operator Laborer 331 POWERHOUSE sitework concrete and forms, building I metal building shell architectural electrical, mechanical water, waste doors crane Super Labor Specialty 7/22/2011 75 (includes directs, indirects, allowance for overtime & per diem) 95 60 hours Labor Equipment No. Durat1on Labor Hours Labor Labor Cost UmtCost Equtp Cost Rate 2 3 wks 360 $95 $34,200 1 2 wks 120 $95 $11,400 2 4 wks 480 $95 $45,600 1 2 wks 120 $95 "$11,400 1 18 wks 1080 $95 $102,600 1 1 wks 60 $95 $5,ioo 0 .5 6 mas 810 $95 $76,950 1 720 Days 54 trips 5 ea 2 75 $75 $5,625 2 75 $75 $5,625 19 cant 1 cont 4 cant 1 cant 3 cant 2 cant 1 cant 1 J cont 1 cont 17 cant 5 ea 2 75 $75 $5,625 2 75 $75 $5,625 400 104 1200 1200 1200 1200 1200 1 0.5 6 wks 180 $95 $17,100 ~I 6 wks 1080 $75 $81,000 6 wks 360 $95 $34,200 Material Umt Untt Cost Matenals Cost I cyd cyd $200 $20,741 sq ft $60 $72,000 sq ft $20 $24,000 sq ft $20 $24,000 sq ft $20 $24,000 sq ft $10 $12,000 ea $40,000 $40,000 I Shipping Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Total Umt Cost Shtp Cost Item Cost $444,450 $34,200 $11,400 $45,600 $11,400 $102,600 $5,700 $76,950 $150 $108,000 $108,000 $900 $48,600 $48,600 $423,000 $7,500 $37,500 $37,500 $5,625 $5,625 $6,000 $114,000 $114,000 $6,000 $6,000 $6,000 $6,000 $24,000 $24,000 $6,000 $6,000 $6,000 $6,000 $18,000 $18,000 $6,000 $12,000 $12,000 $6,000 $6,000 1 $6,000 $6,000 $6,000 $6,000 $6,000 $6,000 $6,000 $7,500 $127,500 $127,500 $7,500 $37 ,500 $37,500 $5,625 $5,625 $349,041 $20,741 $72,000 $24,000 $24,000 $24,000 $12,000 $40,000 $17,100 $81,000 I $34,200 Page A-2 coffer dam/construction diversion impoundment structure shel!t pile concrete footing impoundment wall/spillway 5 ~1 flush gate anchors 10 1 seal ing 1 1 intake/desander base slab 4.7 1 box structure 342 1 trashrack 1 screens 1 1 flush gate 34~1 insulation access hatch/grating 1 1 air relief 1 1 transition to pipeline ~I concrete shut off gate 1 1 controls ~I equipment/storage shed power line, communications 10350 1 Super 0.5 12 wks Labor 12 wks 0 .5 12 wks HOPE I 7700 : Steel I 2650 helicopter (includes fuel) I 1 1 1 ea Labo r 2 1.2 wks hdpe I 175,241 1 flange kits I 1~1 drains/air reliefs anchors I 40 1 coated steel pipe I 73,892 1 thrust block at powerhouse ~I intermediate thrust blocks I anchors I 10 1 victaulic standard couplings 67 Super •I 0.5 12 wks Labor I 4 1 12 wks Specialty O.SJ 12 wks 7/22/2011 lea lcvd lsq ft ea lea ea sq ft ea ea lea cyd lea lea e a Itt 360 $95 I 2880 $75 360 $95 1: I $10,850 1 $180,000 $180,000 145 $75 I lb I ea r a I ea I -l ib lea I ea I lea e a 360 $95 $34,200 1 2880 $75 $216,000 1 I 360 $95 $34,200 I $5,000 $5,000 I $12 $5 ,040 1 $400 $4,444 $50 $2,500 1 $5,000 $5 ,000 $1,000 $10,ooo l $2,000 $2,000 1 $400 $1,896 1 $50 $17,100 1 $1,500 $1,500 $2 ,000 $2,000 1 $2,500 $2 ,500 1 $5 $1,710 . $2 ,000 $2,000 1 $1,000 $1,000 1 $3,000 $3,000 $400 $2,667 1 $2,500 $2,500 $20,000 $2o,ooo l $5,000 $5,ooo l $5.00 $51,750 1 $1 .20 $210,289 1 $1,200 $4,800 1 $500 $6,000 $1,200 $48,0001 $1 .50 $110,838 1 $10,000 $10,000 $3,000 $9,000 1 $2,000 $20,000 1 $1,300 $87,100 I I Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report $5 ,000 $5,040 $4,444 .$2,500 $5,000 $10,000 $2,000 $1,896 $17,100 $1,500 $2,000 $2,500 $1,71.0 $2,000 $1,000 $3,000 $2,667 $2,500 $20,000 $5,000 $51,750 $34,200 $216,000 $180,000 $10,850 $210,289 $4,800 $6,000 $48,000 $110,838 $10,000 $9,000 $20,000 $87,100 $34,200 $216,000 $34,200 Page A-3 133 culverts shot rock soil stabilization reseeding 20000 large culvert at gully 60 gate rock blasting 1481 Super 0.5 9 wks 270 Labor 5 9 wks 2700 ill TI.!I!BI!!I~ AN!;! !ZEN~RATOR IN~TALLATIQN switchgear transformer main valve Super 3 wks 180 3 wks 360 stream channel construction 3000 1 bank stabilization 3000 embankment dike, south side pond 1000 fish access control or ph bypass option 1 culvert or concrete box from ph 1! Super 2 wks 120 Labor 2 wks 360 I 6200 clearing 5.7 geofabric 16533 shot rock 8267 crushed or screened gravel 2756 communicat ions line 620~1 sign age Super 3 wks 180 labor 5 3 wks 900 7/22/2011 $95 $12,667 $1.50 $400 cyd $15 sq yd $0.50 sqyd $0.50 ft $100 ea $7,000 cyd $15.00 $95 $50,000 $50,000 $15,000 ft $13.00 l=a $8 .00 $5.00 $5 ,000 ft $100 $95 $11,400 $75 $27,000 ft ' acre sq yd $1.50 cyd $15 cyd $25 ft $1.00 r a $1,500 $95 $17,100 1 $75 $67,500 $30,000 $4,000 $135,000 $10,000 $10,000 $6,000 $7,000 $22,222 . $50,000 $15,000 $50,000 1 $39,000 $24,000 ~:::1 $3,000 I $24,8oo 1 $124,000 $68,889 $6,200 $3,000 Old Harbor Hydroel~ctric Project Reconnaissance and Feasibility Study Final Report . $12,667 $30,000 $4,000 $135,000 $10,000 $10,000 $6,000 $7,000 $22,222 $25,650 $39,000 $24,000 $5,000 $5,000 $3,000 $11,400 $27,000 $24,800 $124,000 $68,889 $6,200 $3,000 $17,100 $67,500 3 wks 180 3 wks 540 fusion machine 1 1 5 mo 4wheelers 4 1 1 ea 1/3 yard mixer 1 6 mo mix truck 1 1 6 mo small generator 2 1 1 ea large generator ~I 6 mo loader 8 mo excavator 2 1 5 mo end dump 1 6 mo rock hammer 1 ' 6 mo flatbed truck ~I 6 mo trackhauler {marooka) 5 mo dozer 1 1 6 mo hydro ax 1 2 mo . fuel 30ooo l air compressor ~I 6 mo air track drill 6 mo 1 ea 5%1 18,218 15%1 15%1 2.0% 1 1 Owner Procuremen't, Turbine and Generator 1 1 7/22/2011 $95 $17,100 1 $75 $15,000 $75 ,ooo l $9,000 $36,000 1 $1,000 $6,000 $5,500 $33,ooo l $2,000 $4,000 1 $2 ,000 $24,000 $7,000 $56 ,0001 $6,000 $60,0001 $4,500 $27,000 $1,000 $6,000 J $800 $9,600 1 $3,500 $52,500 $4 ,000 $24,000 $5,000 $1o,ooo 1 I gal $800 $4,800 1 $2,000 $12 ,000 lea lea $2,000 $104,000 1 $1.25 S28,875 1 $700 $18,200 1 I $5 .00 $150,000 1 $1,814,562 1 $490,000 $490,0oo l $150,000 $150,000 1 Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report $75,000 $36,000 $6,000 $33,000 $4,000 $24,000 $56,000 $60,000 $27 ,000 $6,000 $9,600 $52,500 $24,000 $10,000 $150,000 $4,800 $12,000 $490,000 $150,000 $150,801 $649.400 $217,200 Page A-5 ISO 9001 Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Appendix B-Construction Schedules ~ WorkingTogether ;p SAfElY Page B-1 F.l,) Hatch 2011/07 Single Season Construction Schedule Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Task Name : Start i Finish I Qtr 1 2013 Qtr 2 2013 ! Qtr 3 2013 Qtr 4 2013 I -----·-----·-·-·-···-------------·------_l ___ ._ ..... __ L ______ _[~~~n~l.-~Eeb~-r-._=Mar~1-=~Qt.=T::M<3i]~~:-~Jm __ c·Yui -J ... ~!!9 __ J.~~~_p ~J~=Qct--~T-NQY::]~ De:g::=t FERC License Application Submitted 1/23/12 1/23/12! ' FERC License Issued 1/17/13: 1i17113 1 + 1/17/2013 Grant/Funding Available 7/2/12 · 7/2/12 1 i 10/19/12 · 10/19/121 Plans/Procurement Documents Construction Contract Awarded 1/17/13 1/17/131 • 1/17/2013 Procurement-Turbine (Owner) 1/17/13 1/17/131 • 1/17/2013 I Procurement-Pipe , Bldg, Materials · 2/16/13 2/16/13 1 • 2/16/2013 : Equipment Mobilization Quarry Development Material Mobilization Access Road Grading/Clearing Access Road Construction Pipeline Trail Clearing Pipeline Trail Construction Pipeline Construction Intake Powerhouse Tailrace Powerline Turbine Installation Startup/Testing Demob Equipment Project : Project1 Date: 7/20/11 7/20/11 5/6/13 . 5/11/13 ! 5/11/13 5/25/13 1 I 5/17/13 6/7/13 ! . I 5/11/13 , 5/18/13 J 5/25/13 6/8/13 ! 5118113 : 5t25t13 / 5/25/13 7/27/13 1 7/27/13 :10/19/131 -. l 7/27/13 :10/19/131 6/8/13 7/20/13 i . I 7/13/13 7/27/13 1 6/8/13 · 6/29/13 1 I : 11/13d3i 11/20/131 11/20/13 12/4/13! 1 0/19/13 l 10/26/131 Task Split Progress .. . l Milestone Summary Project Summary • • ---- • External Tasks External Milestone • Deadline Page B-2 Two Season Construction Schedule Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Task Name : Start Finish ; ,Qtr3 2013 !Otr4 2013 !Qtr1 2014 i Qtr2 2014 1Qtr3 2014 !Qtr4 61igi1:2~ jui1 ;··Ju({-Au9-t sep T oct LNiv 1_[)~c T J~n l E~~1 Mir [APi -t~_GIY_l JU.r.l __ r J~Lt6!:!9 T seQJ 9~{! . -····-·-··-··-······-·-·-··· .. --··--···-·······-'""'' ' •.... ·- FERC License Application Submitted 6/29/12 ' FERC License Issued Grant/Funding Available Plans/Procurement Documents Construction Contract Awarded Procurement -Turbine (Owner) Procurement-Pipe, Bldg, Materials Equipment Mobilization 6/24/13 7/2/12 6/24/13 ! • 6/24/2013 Quarry Development Material Mobilization Access Road Grading/Clearing Access Road Construction Pipeline Trail Clearing Pipeline Trail Construction Pipeline Construction Intake Powerhouse Tailrace Powerline Turbine Installation Startup/Testing Demob Equipment Project : Project1 Date: 7/20/11 7/20/11 7/2/12 1 ' 3/26/13 3/26/13 : i 6/24/13 6/24/13 ! ; 6/24/13 6/24/13 ! 7/24/13 7/24/13 ! 8/8/13 8/13/13 1 I 8/13/13 8/27/13 ! 5/18/14 6/8/14 : 8/13/13 8/20/13 ; I 8/27/13 9/1 0/13 i 8/20/13 8/27/13 ! 8/27/13 5/27/14 i 6/8/14 8/31/14 : 5/27/14 8/17/14 ( 6/8/14 7/20/14 ! 7/13/14 7/27/14 ! ' 6/8/14 6/29/14 ' 8/31/14 9/7/14 ' 9/7/14 9/21/14 ! i 8/31/14 9/7/14 i Task Split Progress • 6/24/2013 • 6/24/2013 • 7/24/2013 • liiiiiiiiiiiiiiii111 1 I It (I I I I I II I till I I IIIIIIJ 1111.11111111 IIIII I till I till IIIII I 111111111 I 111111111 It) ttlt,il I I 11111 11 Milestone Summary Project Summary • e;: • External Tasks External Milestone Deadline Page B-3 ~HATCH™ Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Appendix C -Project Drawings ISO 9001 ~ Work1ngTogether .:7 SAIHV Page C-1 0 Hatch 2011i07 zat•-d "Ott .l!)lrOMd :.tl:t liAU.YlilldOO::I onu:;,nli :r.:wntA 't')IS"tl'f' ~lro¥.. :)UU.:)3'13011QAM ¥011WW cno .......... u-~zq --.,....,.~ ~~ ..... o\ea&IMI-..._...,.._1 ~tas:J-4 ·ON J!)lr0¥4 :x.~ lAU.Ylll400:J ::xM~71J 30\"Tli.A. 'tlfS'I1Y J.:)Jr0il4 :tiM.&:J:nlOfKI.I.Io4 ¥081"WM cno ZLH6-4 "OM .L!J~Oih' :MI:U lAilftl..OO:J :JMIJ.:J1'1J ltWTltA VXSY1Y ~31'0H.. :HIU..:J:nlOtiCl.I.H ¥0H'nt <nO ·I I I l ., I .I I I --·•----·· -~ ~.L __ f--60'---- 1 ------__ ______L____ EDGE OF CREEK SHEETPILE WALL 1-5' INTAKE SITE PLAN "-.l.AL!:. 1",:,'' j ___ _ _ ___ j ________ _ '---- LOWERED SECTION OF WALL LOW HEIGHT DEBRIS WALL SLOPED CONCRETE SLAB ----- TRASHRACK ~----- INFLATABLE GATE OR STOP LOG SECTION 30' SPILLWAY SECTION FLUSH/BYPASS GATES BUTTRESS (TYPICAL) '---DIVERSION WALL SECTION BANK RETAINING WALL FLUSH PIPE, RETURNS TO CREEK EDGE OF CREEK I I I I r+-----~---~----2~ I t r---'1 ''l.._ 1 1 I I l II 1---,d I I I l -:,-l : l f I I I I I I ", : I I I I I I I l 1 r- 1: : I : ll I I : I I I 1 I II I ~I I Lt-----~---;------~ -----' DESANDER SECTION INSULATED DESANDER BOX -----FINAL SCREEN/GRATE FLOOD WALL ELEVATION CUT TRANSITION ·--SHUTOFF GATE EQUIPMENT SHED I VAULT AIR RELIEF " I I .I i I C' I I .I I I I I I I ·I I I ·-_. __ , _____ j_ ·--- -60'- -· L....__~-----·-----• ------ 848' SHEET PILE WALL I 2' 850' EXISTING CREEK BED DIVERSION FOOTING ·-----'-.. ______ '-· ---· ------_i: -· ··-30' SPILLWAY-------.. DEBRIS WALL STOP LOGS OR INFLATABLE GATE ... , FLUSHIBYPASS GATES EXISTING GRADE -', ' '\\ FLOOD WALL \ o TOP OF DESANDER BOX - FINAL FILL SLOPE-'>,\/ '\ -855' r -4' I MAX FLOOD \' NORMAL FLOOD 8' 17 NORMALM WATER VEL DESANDER BOX CUT FOR CONSTRUCTION 6' 1' 2' 1' \ ' CONCEPTUAL DRAWINGS DIVERSION WALL AND INTAKE ELEVATION VIEW k{l~ £ I ! I I I I I .I I I I j ! I I ·I i I tl 0 ,. stALE~ 0.67'+ 850'-· I I ! 2' 848'. ___ :~ J 1 845' ___ / I 3' 1.5' I r 1' -1 SPILLWAY --GROUTED ROCK ANCHOR BUTTRESS WALL CREEK BED- 3' -1 D!VERSION WALL SECTIQN "lf5<'"""1k1~ Or IS<JJ!~ U ~!'IPSOOII> -___........, ·- ------"'" ----- _ 855 , MAX FLOOD BSO' _ NORMAL FLOOD 'v 848' v TRASHRACK- DEBRIS WALL- 845'- FLUSH GATE -- --~.---- -____ , -----' -- ______ [ __ ~ _t r- 1 ---1 -8' ---- TOP OF DE SANDER BOX I I ,--..,.--------..,.-__:~---: -~~ SPILLWAY HEIGHT I MIN WATER LEVEL / SCREEN _/ -SCREEN WALL 6' 1.5' DESANDER BOX DESAN_[)ER SECTIQN (GATES SHOWN FOR REFERENCE ----' I \ PIPELINE CONCEPTUAL DRAWINGS DiVERSION WALL AND INTAKE SECTIONS F£RCP-13U7 -,-- i' I ·I .I I I r~- 1 I I _ _L_ __ --~ ~--24' CLEARED WIDTH ~---~~-~~ 1---12' , ~~-EXISTING GRADE, 3:1 SHOWN CLEAR AND LEVEL EXISTING GROUND ROCK SURFACE -2' BELOW GRADE _ _ _! __ _ ____ ___!____ __ SHOT ROCK BASE 1;1 FILL SLOPE -24' CLEARED WIDTH ~· -EXISTING GRADE, 3:1 SHOWN LAY GEOTEXTILE AND PLACE SHOT ROCK FILL lj_itl~;:::::"::,~::"'"'''_ L- __ l OLD HARBOR HYDROELECTRIC PROJECT 4 ~---T------, J --- GEOTEXTILE ROCK SURFACE -2' BELOW GRADE CONCEPTUAL DRAWINGS ACCESS TRAIL AND PIPELINE SECTION ON 3:1 CROSS SLOPE FERCF>-·22n --------,--- !fJ-c __ rl I I .I I --~-•--------~--___1_.__ ~- r I --24' CLEARED WIDTH ORGANIC MATERIAL FROM TRENCH SHOT ROCK FROM TRENCH '--EXISTING GRADE, 3:1 SHOWN EXCAVATE TRENCH AND PLACE PIPE - POWER AND FIBRE CONDUIT TRENCH ROCK SURFACE -2' BELOW GRADE -------- ----~ -- -. ________ ;11 _______ _ REGRADE TO 2:1 FINAL SLOPE REVEGETATE ---------'------ -24' CLEARED WIDTH ------ \ EXISTING GRADE, 3:1 SHOWN BEDDING OF PIPE AND FINAL GRADING -------· 1.- GEOTEXTILE TRENCH ROCK SURFACE -2' BELOW GRADE CONCEPTUAL DRAWINGS ACCESS TRAIL AND PIPELINE SECTION ON 3:> CROSS SLOPE :a • 1~- ___ 1~--_____ f_ .. L_ _ OCCASIONAL COBBLES OCCASIONAL LOG FROM --- ROAD CLEARING THALWEG -R15' t\ .~ ·· .. p c_= I ~\ I \ \ I \_NEW TAILRACE CHANNEL I I j I I .I I VARIES l_ - SHOT ROCK BASE SWIMMING POND OUTLf:~/T~ILRACE ,CHANNEL PLAN /--STABILIZED i<EVEGETATED BANK / ---8' CRUSHED GRAVEL THALWEG SWIMMING POND OUTLET / TAILRACE CHANNEL SECTION '>CA~ F 1" ~· /ZI/201 - ____ .__ .~ :-?''.c_i!IPlON cr I>SlifS ~ RC\IISO)'<'~ 0.00 .IE O.tt- ,--'-""-,;_ •"--- I ----·---___ ,_ -------_l -'-- EXISTING GRADE -WATER SURFACE 30" CMP -2,100'- 1 INVERT ELEVATION AT-' DISCHARGE ·50' WATER SURFACE CULVERT TAILR,~~f .O~TION, PROFILE EXISTING GRADE -, APPROXIMATE WATER ELEVATION AT FULL PROJECT OUTPUT CULVERT TAILRACE OPTION, SECTION SCIIt[ !"=1 -UNCLASSIFED EARTHEN FILL """lfi:i-1~~~::~~~:::;:~:;:~~;;:~:~0.::·' o\_A'.ft·' -FHC;:I( -c;;rff-1·~~- CONCEPTUAL DRAWINGS TAILRACE AND CULVERT DETAILS AND SECTIONS OLD HARBOR HYDROELECTRIC PROJECT- --,------------r--~.----------'----- ....... 7 --,~ ------ -· r ----J._ --( r_r:: ._ ____ -.J.--l-_jl~~\; I J I ;) SFLl' s:t..tr !--~ "1"•-' __ j TRANSFORMER ~30' --10' OVERHEAD DOOR -' EJA!j 5-.::AL!. J/8'o1' --·-·· ---'·····-'--- 24' POWERHOUSE ACCESS ROAD 30" CMP r~====================================d==== I I I ,' ,-/~========================================= / / /.- FISH SCREEN ___ l_ DAYLIGHT TO CONSTRUCTED TAILRACE CHANNEL POWERHOUSE ELEVATION SECTION CONSTRUCTED TAILRACE CHANNEL CONCEPTUAL DRAWINGS POWERHOUSE PLAN I ,I I I ---~-it __ -11' I I I I " ______ _l~- S'::.kE i'!"-----==:. ,..p,. SHUT OFF VALVE _, __ _ CONCRETE TAIL WATER CHANNELS ELEVATIQN SCALl }/8'" ,. FISH SCREEN r I -16' ACCESS ROAD \ \ 1-EXIST GRADE \ ~ \:1\C,K\ ''1,1/J'F Flf(~91::_ CC·:PFRA 7 \i. OlD HARBOR HYDROElECTRIC PROJECT --,--------------y-. ----- --'--- CONCEPTUAL DRAWINGS POWERHOUSE ELEVATION "ERCP-13:>?2 ---~---,...-- ol ! I ...l_ -----_, -\-- OVERHANGING TREES 'L __ -----·-1-- 40' LONG POWER POLE WITH CROSS ARM FOR 3 CONDUCTORS -----· ---60' TYPICAL CLEARED WIDTH FOR CONSTRUCTION / 'r 24' -1 I _j_ ___ -- APPROXIMATE MAINTAINED LIMIT- OF CLEARING GUY ANCHOR--------- _j ____ _ _ _ ___l ___ _ ~--------- ,! :::~~~~~~==~~:;r=~~~====~==~==db===:~~~========~~::~~=--;---i-~----------------~~~~::::~::~----~L---------------~~~~------1~~~~ I EXISTING GRADE , SCAL~ GEOTEXTILE I SHOT ROCK BASE COURSE 1----------ANCHOR GUY UP TO -30' FROM POLE ---------~ I 10' I I I I I I I I I L l_J OLD HARBOR HYDROELECTRIC PROJECT --,-------, ----- CONCEPTUAL DRAWINGS POWERHOUSE ACCESS ROAD AND TRANSMISSION SECTION ~HATCH™ Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Appendix D-Project Description Alaska Village Electric Cooperative (AVEC), the electric utility provider in Old Harbor, Alaska is seeking to develop a hydroelectric resource near the community of Old Harbor on Kodiak Island. Old Harbor is accessible by small airplanes and boats. Old Harbor is located about 50 miles southwest of Kodiak, AK. The intake is located at about sr 14.7' N and 153 o 20.7' W at an elevation of about 850'. The powerhouse is located at about 57° 14.0' N and 153 o 18.4' W at an elevation of about 85'. The project diversion and intake works will consist of a concrete, or other suitable material, for a diversion/cut off weir with integral spillway. The height of the weir will be approximately 4-6 feet with a length across the creek and floodplain valley of about 1 00'. A water filtering system consisting of a trash rack and/or coanda screens, diversion gates, and secondary screens will be incorporated into the weir structure as a separate desanding box that will be partially exposed above grade. A below grade transition with an above ground air relief inlet pipe will convey water to a buried High Density Polyethylene Pipe (HOPE) pipeline. The pipeline consists of buried HOPE pipe with diameters of 18" to 20" and buried steel pipe with a diameter of 16". A total of 7,700' of HOPE and 2,650' of steel pipe will be installed along a constructed access trail. The access trail will consist of a 12' wide rock fill about 1' to 2' deep placed over a geo-textile filter fabric. Rock cuts and fill will be required in areas of significant terrain and cross slopes. The trail also includes culverts and an access gate. The powerhouse is expected to be a 25' by 35' metal building or similar structure to house the two turbines and associated equipment, switchgear, controls, and tools. The building height is expected to be about 12'. A new 24' wide access road constructed of 2' of rock over a geo-textile will extend from the existing water tank access road to the powerhouse. The 7.2 kV 3 phase overhead transmission line will follow the access road alignment. The power generation equipment will consist of two 262 kW units with a 480 V generator and switchgear for each unit. Only one unit will initially be installed. Each unit will have a hydraulic capacity of 5.9 cfs for a total project peak flow rate of 11.8 cfs capable of producing 525 kW of power. A bypass flow system for maintaining environmental flows, if any are required, is not proposed at this time. A tailrace structure and culvert or constructed stream bed will convey the project flows to the nearby unnamed lake (swimming pond). A constructed tailrace stream or culvert will convey project flows from the unnamed lake to the headwaters of the Lagoon Creek Tributary. The project is a run-of-river hydro that will be operated automatically and primarily in standalone mode as the communities primary source of electrical generation. ISO 9001 ~ WorkingTo!J!IIIer v SAfELY Page D-1 e Hatch 201!/07 Old Harbor Hydroelectric Proj ec t Reconnaissance and Feasibility Study Final Report The following is a summary description of the project components. • Estimated dependable capacity of 130 kilowatts (kW). • Project peak capacity of 525 kW utilizing 11.8 cfs of water with a static head of 765'. • Initial installed capacity of 262 kW utilizing up to 5.9 cfs of water. • A 6' high by 1 00' long cut off (diversion ) wall that will not create any significant impoundment of water. • A 1 0,350' long pipeline consisting of 7,700' of 18" and 20" HOPE pipe and 2,650' of 16" steel pipe. • A 12' wide , 11 ,700' long (approximate) intake access trail. • A single 262 kW Pelton turbine with a hydraulic capacity of 5.9 cubic feet per second (cis ) coupled directly to a 480 volt, 3 phase generator with a provision for a second 262 kW turbine. • A 25'x35' (approximately 900 square-foot) powerhouse. • A culvert or constructed stream tailrace into a lake and subsequent lowlands with final discharge to the Lagoon Creek Tributary . • A 7,700' long (1.5 mile ), 7.2 kV three phase overhead power line. • A 24' wide, 6,200' long access road. Project Flow Diversion Based on the demand profile in 2010, the following chart and table provide predicted diversion flows resulting from project operation. The operation is based on a flat daily total output about 10 kW higher than peak daily demand with a load controller ab sorbing and releasing loads to handle daily fluctuations. Tabl 3 M hi A el -ont 1y verage M ountam ree . c kl n-stream Fl ow an dD' I VerSIOn p otent•a c s . I ( f ) Month 1 2 3 4 5 6 7 8 9 10 11 12 ISO 9001 Monthly Average Mountain Creek In-stream Flow and Diversion Potential (cfs) Avg Existing Flow at In take 3.0 2.2 2.5 3.1 11 .1 40.6 19.2 8.9 10.9 8.7 9.8 3.9 Avg Maximum Potential Diverted by Project 3.0 2.2 2.5 3.1 9.3 11.8 11.5 7.8 8.7 8.4 8.1 3.9 ~ Worki ngTo£!1!lher v SAfEtY Avg D ive rted based on 2010 Dem and 2.6 2.2 2.1 2.4 2.5 2.5 2.5 2.6 2.7 2.5 2.6 2.6 Page 0-2 <>Hatc h 201 1/07 ~ HATCHTM Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Figure 10-Chart of Mountain Creek In-stream Flow and Diversion Potential (cfs) 40.0 35.0 30 .0 25 .0 i u i 20 .0 0 u::: 15.0 10 .0 5.0 0.0 1/1 2120 ISO 9001 4/10 Project Operational Flow 5/30 I~ 7/19 Date ~ Workin&Tol!!!!er v WUY --Mountain Creek Existing Flow -Diverted Flow for Energy, 2010 Demand Based -Maximum Potential Flow Diversion 9/7 10/27 12/16 Page D-3 ~Hatch 2011/07 ~HATCH™ Old Harbor Hydroelectric Project Reconnaissance and Feasibility Study Final Report Appendix E-Mountain Creek Hydrology Report, Old Harbor, Alaska ISO 9001 ~ WorklngTogether v SAFUY Page E 1 "'Hatcl1 2011/07 MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBOR, ALASKA May 4, 2010 prepared for ALASKA VILLAGE ELECTRIC COOPERATIVE 4831 Eagle Street Anchorage, Alaska 99503 prepared by polarconsult alaska, inc. 1503 West 33rd Avenue, Suite 310 Anchorage, Alaska 99503 Phone: (907) 258-2420 POLAR CONSULT ALASKA, INC. TABLE OF CONTENTS MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBOR, AK 1. INTRODUCTION ......................................................................................................................... 1 2. PURPOSE ...................................................................................................................................... 1 3. METHODOLOGY ........................................................................................................................ 1 4. EXISTING DATA .......................................................................................................................... 3 4.1. EAST FORK OF MOUNTAIN CREEK ............................................................................................ 3 4.2. USGS DATA FOR KODIAK ISLAND ............................................................................................ 3 5. COMPARATIVE ANALYSIS ........................................................................................................ 6 5.1. CORRELATION WITH KODIAK RAINFALL DATA ........................................................................... 6 5.2. CORRELATION WITH USGS DATA SETS ..................................................................................... 7 6. ADJUSTMENTS AND FINAL HYDROGRAPH .......................................................................... 9 MAY4,2010 PAGE I POLARCONSUL T ALASKA, INC. 1. Introduction MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBOR, AK As part of updated feasibility study and conceptual design for the Old Harbor Hydroelectric Project, Polarconsult undertook a review of the hydrology data to identify whether the data was sufficient to quantify the economic benefits of the hydroelectric project. Additionally, there have been recent study requests by resource agencies in the Federal Energy Regulatory Commission (FERC) licensing process for additional information on the hydrology. The resource agencies seek to quantify the amount of water for the purpose of both economic and fishery resource evaluation. Figure 1 shows the location of the proposed hydroelectric project and the Mountain Creek drainage. 2. Purpose This report provides a summary and analysis of the hydrology data collected on the East Fork of Mountain Creek. The purpose of this analysis is to: 1. Determine the water quantity from the East Fork of Mountain Creek for hydroelectric production, and 2. Whether additional data collection efforts should be performed for the purpose of quantifying water supply for hydroelectric production. The analysis associated with the first goal is a review and, if necessary, adjustment of the existing data to provide a reasonably confident estimate of water quantity at the intake site on the East Fork of Mountain Creek. This is done using a comparative analysis of the East Fork of Mountain Creek with other know stream flow data sets on Kodiak Island. · The work associated with the second goal is to perform a risk assessment on the estimated water quantity for providing hydroelectric power for the community of Old Harbor and a recommendation on whether additional hydrology data should be collected. This is done by looking at the impacts to the benefits of the hydro project with the uncertainties in the hydrograph for Mountain Creek. 3. Methodology The steps to arrive at the recommended hydrograph for Old Harbor are summarized below: 1. AKDNR data was scaled by the relative basin area of the East Fork of Mountain Creek. 2. The Polarconsult data was aggregated with the AKDNR data and a daily median per basin square mile was calculated. 3. All USGS data sets were collected for Kodiak Island. Data from Terror Lake and River and sites with less than 500 records were excluded. 4. A daily median per basin square mile was calculated for each data set. 5. A daily mean and median was calculated from the aggregate of all USGS medians per basin square mile. 6. The aggregated Mountain Creek data was scaled to more closely fit USGS data. MAY4,2010 PAGE I P OLARCONSUL T A LASKA, INC. I ·-t_,-· ), ~-,; ··r t<'f · 'I ! ---1 -- -MOUTH MOUNTAI~ \ '-\CREEK ~-DRAINAGE, · ~£A •. ~!6 SQ Ml \ j 'i ·_-\1 ) ~ 9 ~; ,. + . 1..,._ _,.~ 35 ~ ~ M OUNTAIN CREEK H YDROLOGY REPORT OLD HARBOR, AK ·/ V.\S~t J ~ ... 0141- 3/1 .. , .. Old Harbot {~ ~ c....---(~ .. -, . 411ortll • • ... + "' ~ lO.ron " ~ . (, . ~ ... CAll:: 12@/20011( ~NG )GJ ~~ ~~ ~ ~ 111 polaroonault alaaka. lno. PRO.Jrcr 1 ------. __.. .. __ • --OLD HARBOR SCAt£: , •• ' !U HYDROELECTRIC PROJECT FU: ...,. •-.,... """" •• IIV1"I1I a•o ..,.,.. (007l ---F"ERC PROJECT NO P-13272 ANCHOUDE, .4l.6RI. 8INl08 PAX (tMW') RDa-INUt MAY4, 2010 PAGE2 oV.J..VV..JV...J ...JVI£.4 J-.L..I.I.\.'-.L.L.I.L \U.I.J.\.J.L..L..J.."-"""'-I..A..J..f ..Jf..JfL.V.J..V ...J.VUo""'J:.J.. .Ll'J POLARCONSUL T ALASKA, INC. 4. Existing Data 4. 1. East Fork of Mountain Creek MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBOR, AK The data for stream flow on the East Fork of Mountain Creek is collected from the Alaska Department of Natural Resources, Division of Mining and Water Management, Alaska Hydrologic Survey, October 1996 Final Report, "Old Harbor Stream Gaging Project". The AKDNR gaged Mountain Creek just below the East and West fork confluence. The elevation at this location is approximately 490' and the drainage area is about 4.6 square miles. The data set begins on 7114/1993 and ext~nds through 5/6/1996 giving a total of 921 records. This data has been scaled by the East Fork sub basin percentage to arrive at a presumed data set for the East Fork. While not exactly data from the East Fork, the AKDNR installed a gage on the East Fork concurrently with this gage from 10117/1995 through 5/611996. The correlation in stage and flow measurements from the two locations indicated that scaling the lower gage site data to the East Fork is reasonable. The stream flow data set that was actually collected at the intake comes from the licensing effort performed by Polarconsult. This data set begins on 611511998 and extends through 8116/2000 consisting of 794 daily records in total. Five stage discharge points were used to develop the stage discharge relationship. The data collected is presented in the Appendix. When combined with the existing AKDNR data, there are a total of 1715 daily records that have been aggregated to daily median values to compare with the USGS data sets. 4.2. USGS Data for Kodiak Island Table 1 lists all of the available data sets from the USGS for Kodiak Island. Only data sets with at least 500 records are used in the comparative analysis. The location of the gage sites is shown USGS Gage Location Map in the Appendix. Each USGS data set was sorted by day and then analyzed to provide the median flow value for each day. This was then divided by the drainage area to arrive a median flow per square mile. The median method of aggregating the data for each day is chosen because the distribution of the data is not normal. It is more typical of a lognormal or gamma distribution. This method of comparison excludes large runoff events from storms skewing the average. Figure 1 shows the resulting median daily flows per square mile for each of the USGS sites. A large amount of variability exists even though the gaged basins are relatively close together. This is due to a noticeable trend towards decreasing precipitation on Kodiak Island when going from the southeast coast to the northwest coast. However, the USGS data exhibits much less variability during the winter and spring low flows which are, at present, the most critical flows when analyzing the Old Harbor Hydroelectric Project economics because those are the lowest flows that occur during the year. MAY4,2010 PAGE3 Poi.ARCONSULT ALASKA, INc. MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBOR, AK Table 1 -USGS Stream Gage Sites on Kodiak Island USGS Site Decimal Decimal Gauge Drainage Beginning End of Number of Number Site Name Latitude Longitude Altitude Area of Record Record Records 15295500 L KITOI C NR AFOGNAKAK 58.1951 152.d670 -1-e u 10/1/1960 9/d0/1961 3% 15295600 TERROR R NR KODIAK AK 57.6506 15d.0d20 -1-2-dG -1-&..{} 6/20/1962 9/d0/1986 adW 15295700 TERROR RAT MOUTH NR KODIAK AK 57.6940 15d.1640 ~ ~ 1/8/1964 10/9/2007 -1+1-00 15296000 UGANIK R NR KODIAKAK 57.6843 -153.4220 20 123.0 4/11/1951 9/30/1978 9994 15296300 SPIRIDON LK OUTLET NR LARSEN BAY AK 57.6771 -153.6520 440 233 5/23/1962 7/15/1965 1150 15296480 LARSEN BAY C NR LARSEN BAY AK 57.5151 -153.9880 800 3.9 8/22/1980 9/30/1984 1501 15296500 Fi\LLS C NR U\RSEN BAY AK 57.2742 15d.9860 ~ &:-7 7125/1 974 9/d0/1 975 ~ 15296520 CANYON C NR LARSEN BAY AK 57.2826 -153.9830 450 8.8 7/25/1974 9/30/1976 799 15296550 UPPER THUMB R NR LARSEN BAY AK 57.3501 -153.9700 380 18.8 7/27/1974 9/30/1982 2988 15296600 KARLUK RAT OUTLET NR LARSEN BAY AK 57.4429 -154.1140 360 100.0 8/21/1975 9/30/1982 1868 15296950 AKALUR/\ CAT OLGA BAY AK 57.1659 154.2290 2{} 4&4 8/22/1975 9/d0/1 976 400 15297000 DOG SALMON C NR ,1\YAKULIK AK 57.2076 154.07d0 JaG ~ 12/10/1959 9/d0/1961 48-9 15297100 HIDDEN BASIN C NR PORT LIONS AK 57.5942 -153.0150 1500 3.0 8/1/1982 1/31/1984 549 15297110 HIDDEN B/\SIN C NR MOUTH NR KODIAK AK 57.5626 152.9610 2{}0 ~ d/1/1983 1/31/1984 ~ 15297200 MYRTLE C NR KODIAK AK 57.6026 -152.4060 20 4.7 5/22/1963 9/30/1986 8533 15297450 MF PILLAR C NR KODIAK AK 57.7987 -152.4520 175 2.0 10/1/1968 5/31/1970 608 15297470 MONASHKA C NR KODIAK AK 57.8420 -152.4480 20 5.5 6/25/1972 9/30/1976 1559 15297482 FALLS C NR PORT LIONS AK 57.6681 -152.9360 1500 4.3 10/1/1980 9/30/1983 1095 15297485 KIZHUYAK R NR PORT LIONS AK 57.7098 -152.8710 15 47.5 4/1/1980 9/30/1994 5296 E FORK MOUNTAif::J"S:~(~,Q~~~~~g.L ... 57.2450 -153.3442 840 1.8 7/14/1993 8/16/00 1715 Notes: Strikeout gage stations excluded in analysis because of small number of records. MAY4, 2010 PAGE4 POLARCONSUL T ALASKA, INC. 60.0 --------------·-- -UGANIKRNR -SPIRIDON LK -LARSEN BAY 50 .0 -CANYON C NR 40 .0 ·e tJ' tn :! ~ 30.0 ~ u:: ~ c :::::> 20 .0 10.0 -UPPER THUMB KARLUK RAT -HIDDEN BASI -MYRTLECNR MF PILLAR C -MONASHKAC -FALLSCNR -KIZHUYAKR -East Fork Mountain MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBoR, AK 0 .0~~~~~~~=::::~~~~~~~~~ 1/1 1/31 3/2 4/1 MAY4,2010 5/2 6/1 7/2 Day of Year Figure 1 8/1 9/1 10/1 11/1 12/1 PAGES POLARCONSUL T ALASKA, INC. MOUNTAIN CREEK HYDROLOOY REPORT OLD HARBOR, AK 5. Comparative Analysis 5. 1. Correlation with Kodiak Rainfall Data Rainfall in Kodiak showed a strong correlation with the runoff data collected in Old Harbor during the summer of 1998. This correlation is shown in the following chart. Summer 1998 Old Harbor Project Stream Flows 180 ~---------:--;::::====================::::;-TI---1 4.0 -Mountain Creek, Canyon -Intake 3.5 -Mountain Creek, Mouth 3.0 -Kodiak Rainfall (in) 1.0 6/17 6/24 7/1 7/8 7/15 7/22 7129 8/5 8/12 8/19 8/26 9/2 9/9 9/16 9/23 9/30 10/7 Date The entire Kodiak rainfall record is shown in the chart below. The wettest year of record occurred in 1998. Thus the limited hydrology data collected on Mountain Creek is probably slightly skewed to indicate more runoff than average. In fact, the average total rainfall for the years 1993 through 1996 and 1998 through 2000 is 80" versus the average for the period of record which is 65". Thus, the observed runoff may actually need to be adjusted down by about 20%. 100 80 ~ 60 c ~ 40 20 Kodiak Rainfall Data 0~----~------~------~--------------~----~------~ 1931 1941 1951 1961 1971 1981 1991 2001 Year MAY4,2010 350 300 ~ 0 250 ~ C» Cll .c 200 0 0 .. 150 C» .c E = 100 z 50 PAGE6 POLARCONSUL T ALASKA, INC. MOUNTAIN CREEK HYDROLOGY REPORT OLD AK 5.2. Correlation with USGS Data Sets The comparison of the East Fork Mountain Creek data with the combined USGS data sets shows that the Mountain Creek data set has higher than average flows year round but is still within the range of the observed USGS gage site data. The most significant deviation appears to be summer flows that are quite higher than average for all of the USGS basins as shown in Figure 1. Table 2 gives an indication as to a likely reason this. The Mountai!l Creek intake is located at a fairly high elevation. Three other USGS gage sites are at similar elevations -Larsen Bay Creek, Hidden Basin Creek, and Falls Creek. Larsen Bay Creek is noticeably drier mainly due to its location on the middle northwest coast, which puts it in the lee of the predominant flow pattern across the island. The other two locations exhibit significantly higher than average summer flows. Therefore, it is not unexpected that Mountain Creek has higher than average summer flows as well. Fall flows at Mountain Creek represent the second highest when included in the USGS data set. The location of Mountain Creek, near the highest peaks on the southeast coast is certainly a reasonable explanation for the high rates of runoff during fall because of the predominant flow pattern coming in from the Pacific Ocean and the high altitude of the basin. The most concerning aspect of the Mountain Creek data set is the higher than average winter flows. Mountain Creek ranks 3rd out of the 12 USGS sites and is 33% higher than the average. The disparity is especially apparent when it is observed that the highest winter producing gage sites are very near sea level. Given that both the AKDNR and Polarconsult rating curves lacked low flow resolution it seems that the most likely reason for the unusually high winter flows is a deficient rating curve in the low flow readings. In other words, the Mountain Creek data set should have winter time flows that are closer to the average of the USGS sites. MAY4,2010 PAGE7 POLARCONSUL T ALASKA, INC. MOUNTAIN CREEK HYDROLOGY REPORT OLD AK Table 2-Seasonal Average Unit Flows USGS Site Gauge Drainage Annual Number Site Name Altitude Area J~:~Q:~I:J9 .... §~P.:~C?':'. Dec-Mar .. !\.P.!::."'!§IJ. . }\y~r§lg~ -~,~~~M~>M' 0>0<>0C"A 15296000 UGANIK R NR KODIAK AK 20 123.0 10.1 3.7 1.1 4.1 4.5 15296300 SPIRIDON LK OUTLET NR LARSEN BAY AK 440 23.3 2.1 1.9 1.9 2.7 2.1 15296480 LARSEN BAY C NR LARSEN BAY AK 800 3.9 2.1 2.2 1.5 3.5 2.2 15296520 CANYON C NR LARSEN BAY AK 450 8.8 7.7 5.7 1.3 4.6 4.6 15296550 UPPER THUMB R NR LARSEN BAY AK 380 18.8 6.5 4.2 1.7 4.8 4.1 15296600 KARLUK RAT OUTLET NR LARSEN BAY AK 360 100.0 4.3 3.8 1.9 3.2 3.2 15297100 HIDDEN BASIN C NR PORT LIONS AK 1500 3.0 31.4 7.8 1.5 7.8 11.6 15297200 MYRTLE C NR KODIAK AK 20 4.7 6.3 6.3 3.4 9.2 5.8 15297450 MF PILLAR C NR KODIAK AK 175 2.0 6.4 9.0 4.1 10.1 6.9 15297470 MONASHKA C NR KODIAK AK 20 5.5 8.4 5.6 2.1 10.7 6.0 15297482 FALLS C NR PORT LIONS AK 1500 4.3 23.9 6.5 1.9 6.5 9.3 15297485 KIZHUYAK R NR PORT LIONS AK 15 47.5 8.4 3.6 2.7 4.1 4.6 E FORK MOUNTAIN C 840 1.8 15.6 8.3 2.8 6.2 7.9 9.8 5.0 2.1 5.9 5.4 MAY4, 2010 PAGE8 POLARCONSULTALASKA, INC. MOUNTAIN CREEK HYDROLOGY REPORT OLD AK 6. Adjustments and Final Hydrograph Based on the comparison above and the known lack of stage discharge measurements below 6cfs for the AKDNR data ( 40% of 15cfs) and 1 Ocfs for the Polarconsult data it is recommended that the existing Mountain Creek data should be adjusted to match the USGS for during winter months. Although only the winter data appears to require an adjustment, we recommend that all of the data be adjusted down to a varying degree to account for the Jack of a longer term and more focused effort to obtain stream flow data on Mountain Creek. The adjustments made bring the data set more in line with the average of the USGS data sets. While this is a conservative approach, it is reasonable to opt for this reduced data set in lieu of performing additional streamflow measurements. The following table shows the adjustments applied to the monthly averages ofthe Mountain Creek data. Table 3-Mountain Creek Adjustments to Mean Monthly Unit Flows Mountain USGS Creek Mean 3.0 57% 1.70 1.8 1.5 2.7 56% 1.50 1.8 1.5 1.8 61% 1.10 4 2.9 2.2 2.7 74% 2.00 5 9.0 6.7 9.6 93% 9.00 6 14.6 11.4 25.9 85% 22.00 7 10.5 6.2 14.1 85% 12.00 8 4.4 2.9 6.7 68% 4.50 9 5.8 4.4 11.0 50% 5.50 10 5.2 4.3 9.1 55% 5.00 11 4.0 3.1 4.6 69% 3.20 12 2.8 2.2 3.8 53% 2.03 Figure 2 shows the final recommended unit hydrograph with the median and average of the USGS data sets included and Figure 3 shows the final recommended hydrograph at the intake site of Mountain Creek. MAY 4, 2010 POLARCONSUL T ALASKA, INC. MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBOR, AK -·e C" i 60.0 ~----------------------------------------------------------------------~ so.o +-------------------~----------~--------------1----~u~s~G~S~M~e~an~--~------~ -USGS Median -Adjusted Unit Flow 40.0 +------------------------H-- ~ 30.0 ~ i! 1/1 MAY4,20l0 1/31 3/2 4/1 5/2 6/1 7/2 Day of Year 8/1 9/1 10/1 11/1 12/1 Figure 2 -Mountain Creek Adjusted Unit Flows Compared with USGS Mean and Median PAGE 10 I. POLARCONSUL T ALASKA. INC. M OUNTAIN CREEK H YDROLOGY REPORT OLD HARBOR. AK 50.0 45 .0 40.0 35.0 :i ~ ~ 30.0 0 u:: E 25.0 "' Q) ... ... UJ c 20.0 .!!! 'C Q) ::! 15.0 10.0 5.0 0 .0 MAY4, 2010 Fi gure 3 -Final Hy d ro g r~h and Power Output for Old Harbor H ydr~electr i c P roject II I j\ I '' .I ,II I II ,11 1 II ~ II 1 1 I '!/ tl ' \ \ \ ~ v -Final Recommended Flow 1 / -Power Output I I "' t I I , I lid I • • It I \ f \' I '. J I I Ill ! \, ll \ ~ \ \I I I \ 350 300 250 ~ 200-:; c. ... ~ 0 ... 150 ; 100 11 50 0 ll. ~----------------------------------------------------------------~ 0 1/1 1/31 3/2 4/1 5/2 6/1 7/2 8/1 9/1 10/1 11/1 12/1 Day of Year PAGE 11 t . POLARCONSUL T ALASKA, INC. MOUNTAIN CREEK HYDROLOGY REPORT . OLD HARBOR, AK If constructed and operated at full potential year round, the project would have the following impact on median flows at the canyon of Mountain Creek. 50.0 100% 45.0 -water Use for Hydro 90% c 40 .0 --Canyon Mountain Creek Median Flows 80% 0 >-c ftS -% Reduction in Canyon Mountain Creek Flows 0 -35.0 70% ftS -J!! t,) -:= 30.0 0 u:: ~ ..2 60% u. ~ Q) e E 25.0 ftS e -en 50% 0 c s :I c 20.0 .!! 40% 0 ::!: "C Q) .5 ::!: 15 .0 c 30% 0 :;::; t,) :I "C 10.0 20% Q) 0:: ~ 0 5.0 10% 0.0 0% 1/1 1/31 3/2 4/1 5/2 6/1 7/2 8/1 9/1 10/1 11/1 12/1 Day of Year MA.v4, 2010 PAGE 12 POLARCO;-.JSULT ALASKA, INC. APPENDIX Polarconsult Mountain Creek Stream Gage Data USGS Gage Location Map MAY4,2010 MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBOR, AK 7 Pages 1 Page PAGE 13 POLARCONSUL T ALASK.I\, INC. Location intake intake intake intake intake MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBOR, AK STAGE DISCHARGE DATA Date Recorder Flow WA •~/, ~.J "'¥"·~~~~~·~·~~~--''"'"~ 8/16/2000 0.78 10.6 6/3/1999 1.18 24.8 10/7/1998 0.82 11.7 8/14/1998 0.8 9.5 6/15/1998 1.42 45.3 y = 1.6207e2335x 40.0 +--------------------.. ---R2 = 0.9897 --------J,_ ______ .. _, ~ 30.0 -l-----.. -... -_ .. ________ .. ____ .. _______ .. ___ .. ______ __,_ _________ 1 -G) ~ 25.0 +---.. -------·--------------·----·---------·----·-.... ----.. -·---·---1 .c (,) 2i 20.0 +--.... ____ .. ___ .. ______________________ _, _______ .. _______ -i 5.0 0.0+-----~----~---·-----,----------,---~--~ 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Depth (ft) MAY4, 2010 PAGE 14 ""'v•vv..Jv..J ,J V I ""' J." .&.01.1.'-'"-J. J.JJ." \U.&..I.V.I...I..·\,.;•'-4•/ ..Jf..Jf""'V•v J. vv. "'Z• ., ... POLARCONSULT ALASKA, INC. MOUNTAIN CREEK HYDROLOGY REPORT OLD HARBOR, AK POLARCONSULT EAST FORK MOUNTAIN CREEK FLOW DATA Didlt. I ,.. I I Date 1 FlOw I I ~ -J." .flow I I 6/15/1998 43.31 7/29/1998 22 .71 9/11/1998 14.98 6/16/1998 46.78 7/30/1998 21 .29 9/12/1998 18.08 6/17/1998 53.26 7/31/1998 21.20 9/13/1998 .17.90 6/18/1998 51.06 8/1/1998 20.66 9/14/1998 15.54 6/19/1998 50.63 8/2/1998 19.67 9/15/1998 13.49 6/20/1998 53.83 8/3/1998 18.78 9/16/1998 12.05 6/21/1998 53.16 8/4/1998 17.57 9/17/1998 11 .29 6/22/1998 47.69 8/5/1998 16.18 9/18/1998 11 .85 6/23/1998 42.47 8/6/1998 14.73 9/19/1998 25.09 6/24/1998 38.76 8/7/1998 14.49 9/20/1998 58 .77 6/25/1998 40.52 8/8/1998 14.58 9/21/1998 44.18 6/26/1998 44.03 8/9/1998 14.03 9/22/1998 30.31 6/27/1998 50.02 8/10/1998 13.11 9/23/1998 23.10 6/28/1998 56.96 8/11/1998 12.24 9/24/1998 19.28 6/29/1998 68.08 8/12/1998 11.43 9/25/1998 17.16 6/30/1998 67.84 8/13/1998 10.74 9/26/1998 15.61 7/1/1998 57 .28 8/14/1998 10.35 9/27/1998 14.56 7/2/1998 49.65 8/15/1998 9 .90 9/28/1998 13.48 7/3/1998 63.23 8/16/1998 9.66 9/29/1998 12.77 7/4/1998 54.00 8/17/1998 9.29 9/30/1998 11.92 7/5/1998 42.50 8/18/1998 9 .27 10/1/1998 11 .05 7/6/1998 36.30 8/19/1998 9.08 10/2/1998 10.33 7/7/1998 31 .58 8/20/1998 9 .17 10/3/1998 9 .80 7/8/1998 27.54 8/21/1998 8 .89 10/4/1998 10.26 7/9/1998 25.35 8/22/1998 8.54 10/5/1998 10.27 7/10/1998 24.57 8/23/1998 8.29 10/6/1998 10.26 7/11/1998 23.52 8/24/1998 8.15 10/7/1998 10.90 7/12/1998 24.05 8/25/1998 7 .95 10/8/1998 11.44 7/13/1998 27.34 8/26/1998 7 .64 10/9/1998 11 .00 7/14/1998 29.93 8/27/1998 7.48 ' 10/10/1998 10.51 7/15/1998 32.49 8/28/1998 7.36 10/11/1998 9.78 7/16/1998 30.66 8/29/1998 7 .32 10/12/1998 10.00 7/17/1998 27.45 8/30/1998 7 .66 10/13/1998 9.56 7/18/1998 24.00 8/31/1998 9.58 10/14/1998 9 .25 7/19/1998 21.30 9/1/1998 10.40 10/15/1998 9.63 7/20/1998 24.54 9/2/1998 14.07 10/16/1998 10.33 7/21/1998 71.42 9/3/1998 19.36 10/17/1998 10.82 7/22/1998 59 .30 9/4/1998 19.32 10/18/1998 11 .54 7/23/1998 44.24 9/5/1998 18.39 10/19/1998 13.35 7/24/1998 ·35.39 9/6/1998 16.62 10/20/1998 15.49 7/25/1998 32 .05 9/7/1998 14.67 10/21/1998 16.76 7/26/1998 31 .37 9/8/1998 13.06 10/22/1998 17.67 · 7/27/1998 28.96 9/9/1998 12.14 10/23/1998 16.20 7/28/1998 25.90 9/10/1998 14.63 10/24/1998 15.12 MAY4, 2010 PAGE 15