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Home My WebLink AboutGunnuk Creek Appendix AHydropower Reconnaissance Report for Kake, Alaska — 2013 Introduction Existing electrical load in Kake is approximately 350 kVVwithout Cold Storage operations, approximately 800 kW while the Cold Storage is running. The local utility is owned by IPEECand they run diesel generators to produce electricity. Approximately 216,000 gallons of diesel was burned for electricity in 2012 at a total cost of $860,000. The cost of electricity in Kake during 2012 was 63 cents per M. Sate PCEsubsidiesfor Kake residential energy totaled $480,000 in 2012 (see attached PCEstats page). CLrrently, the Ftl only applies to residential use that does not exceed 500 M. Hydropower development options near the community of Kake are limited because of relatively gentle topography and regionally low precipitation, however, both Gunnuk and Cathedral Falls systems have been evaluated to some degree in the past. In recent years the State of Alaska and IP[Ehave been focusing on developing the Kake-Petersburg Intertie for delivering hydroelectricity to Kake. The Kake-Petersburg Intertie (M) has been studied by consultants and agencies for over 10 years and has been discussed as an infrastructure need for at least 40 years. Recent studies have concluded that the 1,R cannot provide a guaranteed supply of hydroelectricity to meet Kake's total load forecast because of contractual obligations to the communities of Wrangell, Petersburg and Ketchikan (see Kake- Petersburg Transmission Intertie Study Update, 2012). The 2009 estimated cost of the PI is expected to be 3040 million dollars resulting in an estimated consumer side cost of approximately 34 oents per kWh. In light of this information we believe it is worth taking another look at local hydropower options to complement a possible PR. Basic Etats for Hydro -feasibility in the G.Annuk Creek Watershed • The Gannuk Creek watershed isapproximately 10,000 acres. • There are approximately 38 miles of stream in the watershed. • The land is owned by 9ALASM and Kake Tribal Corporations and there is a ,'T--ALIRJSr conservation easement within the watershed (see attached map). • There is an existing dam at —125 feet elevation that was designed to provide reliable drinking water and run of the river power (up to 11 kW) for the Gunnuk Creek Hatchery. • The Hatchery currently has aooessto 22 cis of flow for overall operations • A small lake (Alpine Lake) exists in the upper reaches of a secondary tributary to Clannuk Creek and currently provides drinking water to the community. Approximately .5 cfs is currently required to meet local water consumption. Community water was historically provided by Gunnuk Creek at the 125' dam site but is now being pulled from Alpine Lake because of economic considerations There is concern in the community that the Alpine Lake site provides a less healthy water supply because the lake is relatively stagnant. Development of a hydro -facility could allow for returning the water tap to the Kake Dam and improving drinking water quality. Based on US3Sflow data for 2005-2008, annual mean flow at the hatchery site rangesfrom 77 ds to 111 cfs, monthly mean flows range from 36 cfs to 167 cfs, daily mean below 40 cts occ ur approximately 45 %of the total USGSrecord and for up to 5 weeks at a time, daily mean below 60 cfs occur approximately 58 %of the total U83Srecord and for up to 5 weeks at a time. Hydroelectrical Development Options A study was conducted in 1977 that looked at developing hydroelectrical power in Qannuk (reek by impounding the primary tributaries into a 586 acre lake (see attached). The study estimated that this reservoir could provide a continuous flow of 75 cfs to a 1,000 kW powerhouse. Alternatively, we have been studying the possibility of creating smaller reservoirs (136 & 141 Acres acres) in two different tributaries of the Gunnuk Watershed (see attached). In the Al pine Lake Scenario, the reservoir would be used to augment total Creek flows during low flow periods in a run of the river scenario that would include an intake at 330 feet of elevation and a 2.5-2.75 mile penstock (depending on powerhouse location). Rows into Alpine Lake basin are unknown but are estimated to bean annual mean of 7.5 cfs. There is an out of basin opportunity for augmenting flows to Alpine Lake from the Turn Mountain watershed that is estimated to have an annual mean of 7.5 cfs. In the Qannuk Lake Scenario, the reservoir would provide the sole source of flow to the powerhouse. Annual mean flowsto this reservoir are estimated at 13.5 cfs. There is an out of basin stream nearby that would provide an additional annual mean of 9 ds and derivesfrom elevations and slopesthat may be favorable for capturing late spring snow melt . This scenario would require less fill, would capture more flow at the reservoir and provide considerably more head than the Alpine Lake Scenario but it would require a longer penstock (4.4 miles vs 3 miles). Some questionsthat need to be answered to better understand the feasibility of these designs are: 1. Can these reservoir designs be maintained by existing+out of barn flows under adequate power generation scenarios? 2. Which, if any, of the designs are economically feasible? The table below summarizes a rough estimate of power availability for the two designs described above. Alpine Lake Scenario K/ at 20 cfs KW at 40 cfs KW at 60 cfs Power Available at Dam Ste (200' Head) 268 531 999 Power Available at Hatchery Ste (300' Head) 370 734 1105 136 Acre Feservoir Capacity (in days) 397 200 133 Gunnuk lake Scenario KW at 20 cfs KW at 40 cfs KW at 60 cfs Power Available at Dam Ste (400' Head) 536 1062 1597 Power Avallable at Hatchery Ste (475' Head) 634 1256 1890 141 Acre Reservoir Capacity (in days) 198 100 67 Initial reconnaissance of the Alpine Lake option suggests that it would be worth conducting some stream gaging and rough design work for cost -benefit analysis. The attached map indicates the location of three gaging locations that would provide information on out of basin water supply, existing lake recharge rates and total combined flow at a possible intake site. Our hope is that IPEC, the city of Kake, Kake Tribal Corp and the Organized Village of Kake would consider using this report as a bas sfor submitting a joint proposal to AEA to develop a more robust feasibility study Gunnuk Creek Hydroelectrical potential. Kake Fa Utility: I N8 DE PASS4GE 9 EcTHC R4"tin9PLrioc!- 07/01111..0&/30112 Community Population 557 Last Peported Month June No. of Monthly Payments Made 12 ilsidential Customers 235 Community Facility Customers 16 R Other Customers (Non-PCF) 56 Fiscal Year PCEPayments x $479,138 - -- -b•" PCE Statistical Data PCE9igiblekM- Residential Customers 893,785 AverageAnnual PCEPaymentper Eligible $1,909 Customer I�EligiblekWh-CbmmunityFacility 238,531 Average PCEPaymentper 9igiblekM $0.42 Customers Total FC Bigible kWh 1,132,316 Last Reported ibadential Rye Charged $0.63 (based on 500 kWh) Average Monthly PCE9igiblekWh per 317 Last imported PC=Level (per kWh) $0.42 Residential Customer Average Monthly PCE9igible kWh per 1,242 Effective Residential Rate (per kWh) $021 Cbmmunit Facility Customer Average Monthly PCEBigible Clommunity 36 PCE9igiblekMvsTotalk 'bid 43.4% Facility kWh per person Additional Statistical Data Reported by Co nrnunity` Generated and Purchased kM26,541 Generation Costs Diesel kWh Generated Fuel Used (Gallons) 216,348 Non -Diesel kWh Generated Fuel Cost $862,275 Purchased kWh Average Rice of Fuel $3.99 Total Ftirc based & Generated Annual Non -Fuel E ¢penses $580,032 Non -Fuel 6¢�ense per kWh sold $0.22 Omwmed and Sold kWh E fiaency and Une Loss Fesidentid kWh SbId*kM51,800 8,439 Consumed vs Generated (kWh SbId vs 90.4% Generated-Purdhased Community Facility kWh S>Id7,737 Line Loss (%) Other kWh Sold Pon-PCB3,806 Fuel Efficiency (kWh per gallon of diesel) 7 $% 13.34 Total kWh SbId9 982 rbwerhouse (PI-() Consumption Total kWh Wid & Ffi Cbnsump,1, 782 comments 7hedata contained inthisreportisprimarilybased oninformation submittedbytheutilitywiththeirmonthlyFCEreports Changesto the reported data andror significant anomalies have been noted in the comments Fbge 74 of 179