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HomeMy WebLinkAboutBradley Lake Hydropower annual energy increase possibility 02.26.2010Bradley Lake Hydropower annual energy increase possibility A possible water significant water source for Bradley Lake Hydroelectric project is located two miles to the West of the Project. The middle branch of Battle Creek emerges from a glacier two miles west and 1000’ higher than the lake (Figure 1). The smaller east branch is already diverted into the lake. Battle Creek was gaged at tidewater and at elevation 780’ in 1991 — 1993 (Attached). The annual flows indicate 50,000 ac-ft water at 780’and 87,000 ac-ft of water at tidewater. Lower Battle Creek does have salmon. Since tidewater measures down to 10 cfs during winter the environmental flow required would be expected to be low. Feasibility/permitting could provide more information on environmental flows. The contribution of the West branch of Battle Creek to the tidewater amounts may cover most required environmental flow. There is very little difference in drainage area between elevation 780’ and 2000’. Assuming that the measured 780’ flows flow can be diverted to Bradley Lake then Bradley would have an increase of approximately 50,000 MWhrs. One ac- ft of water at Bradley is nearly equal to 1 MWhr. A short road of 1.5 miles could be built from the existing Bradley road to the tunnel exit at 1650’. Tunnel (~9000’) would be constructed and would be used for initial access to the 2000’ level to build the small diversion dam. A small rock gabion dam could be built to divert the water. Once built the road access would no longer be needed to the upper elevation and water would flow down the tunnel to Bradley Lake. Other possible less expensive routes may be present. Diversion site appears to be on State DNR land. Since the river has salmon downstream the diversion would likely required an amendment to the existing Bradley license. A rough cost estimate: Permitting & design (guess) $2,500,000 Road (1.5 miles est.) $3,000,000 Tunnel blasting ($2000/ft) $18,000,000 Dam $500,000 Estimate $24,000,000 Contingency (25%) $6,000,000 Total Estimate $30,000,000 There are other options to divert flow than a long tunnel. Other routes would likely have shorter tunnel sections and lower costs to construct. Amount of required environmental flows will determine amount of energy gained at Bradley. Stream flow at the 2000’ elevation would need to be gaged, permitting reviewed, and a new cost estimate prepared. USGS Surface Water data for Alaska: USGS Surface-Water Monthly Statistics Page | of 2 a USGS ele et ted USGS Home Contact USGS Search USGS National Water Information System: Web Interface Data Category: Geographic Area: Surface Water Alaska GO | News - updated January 2010 USGS Surface-Water Monthly Statistics for Alaska The statistics generated from this site are based on approved daily-mean data and may not match those published by the USGS in official publications. The user is responsible for assessment and use of statistics from this site. For more details on why the statistics may not match, click here. USGS 15238982 BATTLE C BL GLACIER NR HOMER AK Available data for this site Time-series: Monthly statistics | GO | Kenai Peninsula Borough, Alaska Hydrologic Unit Code 19020301 Latitude 59°44'19", Longitude 150°53'49" NAD27| Drainage area 11.8 square miles Gage datum 780 feet above sea level NGVD29 Output formats 00060, Discharge, cubic feet per second, Monthly mean in cfs (Calculation Period: 1991-10-01 -> 1993-09-30) Jan || Feb | Mar} Apr ||May} Jun || Jul | Aug | Sep || Oct | Nov|| Dec 1991 34.4|| 13.3]] 5.42) 1992 7.37] 4.47} 3.82)| 6.50)| 44.8)) 151.0]) 159.4] 148.4) 36.0} 29.3], 36.1)| 19.3 1993 || 6.39] 7.84) 6.93]| 20.4] 89.2) 164.8] 221.9]| 281.5] 145.2 Mean of monthly || 6.9] 6.2] 5.4 13] 67] 158) 191) 215 91} 32] 25] 12 Discharge) YEAR ** No Incomplete data have been used for statistical calculation Questions about sites/data? Top Feedback on this web site Explanation of terms Automated retrievals Subscribe for system changes Help News Accessibility FOIA Privacy Policies and Notices U.S. Department of the Interior | U.S. Geological Survey TSA.cov Title: Surface Water data for Alaska: USGS Surface-Water Monthly Statistics URL: http: //waterdata.usgs.gov/ak/nwis/monthly? http://waterdata.usgs.gov/ak/nwis/monthly?referred_module=sw&site_no=15238982&por... 2/26/2010 USGS Surface Water data for Alaska: USGS Surface-Water Monthly Statistics Page 1 of 2 ZUSGS Etre Pe eee USGS Home Contact USGS Search USGS National Water Information System: Web Interface Data Category: Geographic Area: —— Surface Water Alaska l Go | News - updated January 2010 USGS Surface-Water Monthly Statistics for Alaska The statistics generated from this site are based on approved daily-mean data and may not match those published by the USGS in official publications. The user is responsible for assessment and use of statistics from this site. For more details on why the statistics may not match, click here. USGS 15238985 BATTLE C NR TIDEWATER NR HOMER AK Available data for this site _ Time-series: Monthly statistics [GO } Kenai Peninsula Borough, Alaska Output formats Hydrologic Unit Code 19020301 HTML table of all data Latitude 59°45'20", Longitude 150°57'12" NAD27| Drainage area 21 square miles Tab-separated data Gage datum 90 feet above sea level NGVD29 Reselect output format 00060, Discharge, cubic feet per second, Monthly mean in cfs (Calculation Period: 1991-08-01 -> 1993-09-30) Jan || Feb || Mar || Apr || May || Jun Jul || Aug || Sep || Oct | Nov || Dec 1991 292.3|| 333.7] 69.8}| 28.3]] 14.1 1992 16.5] 12.7] 10.8] 21.5] 111.2) 282.6]| 282.7]| 304.3]} 61.1} 55.9]| 89.9]| 46.7, 1993 11.6] 18.5|| 14.8] 50.4]) 148.7] 230.3]| 295.5|| 391.0] 201.3 Mean of monthly 14) 16) 13) 36) 130) 256 289/) 329) 199] 63] 59} 30 Discharge YEAR ** No Incomplete data have been used for statistical calculation Questions about sites/data? Top Feedback on this web site Explanation of terms Automated retrievals Subscribe for system changes Help News Accessibility FOIA Privacy Policies and Notices U.S. Department of the interior | U.S. Geological Survey Title: Surface Water data for Alaska: USGS Surface-Water Monthly Statistics URL: http://waterdata.usgs.gov/ak/nwis/monthly? http://waterdata.usys.gov/ak/nwis/monthly?referred_module=sw&site_no=15238985&por... 2/26/2010