MANN CREEK BURNT RIVER BROWNLEE RESERVOIR RESERVOIR (0.26) WEISER RIVER UNITY RESERVOIR (0.13) CRANE CREEK RESERVOIR CASCADE DEADWOOD RESERVOIR RESERVOIR (0.52) PAYETTE RIVER BEULAH BULLY CREEK RESERVOIR RESERVOIR MALHEUR RIVER BLACK CANYON (0.15) RESERVOIR (0.16) ARROWROCK RESERVOIR WARM SPRINGS BOISE RIVER (0.13) RESERVOIR SNAKE RIVER OWYHEE RIVER LUCKY PEAK RESERVOIR OWYHEE RESERVOIR ANDERSON RANCH RESERVOIR SWAN FALLS RESERVOIR Sediment Date Yield of Reservoir (ac-ft/mi2/yr) Measurement Arrowrock 0.11 1947 Arrowrock 0.15 1997 Black Canyon 0.17 1936 Black Canyon 0.15 1971 Bully Creek 0.15 NEED DATA Cascade 0.52 1995 SNAKE RIVER Mann Creek 0.13 unpublished Mann Creek 0.39 1992 Unity 0.13 1991 AMERICAN FALLS RESERVOIR Measured sediment yield values shown in acre-feet/mi2/year Estimated sediment yield value of 0.15 acre-feet/mi2/year Technical Report E.1-2 Figure 4.1 HELLS CANYON HYDROELECTRIC COMPLEX Basinwide Sediment Yield Computation Schematic An IDACORP Company P:\155638\Graphics\Geomorphologyfigs.fh10 17-Dec-2001 P:\155638\Graphics\Geomorphologyfigs.fh10 15-Dec-2001 (Source: P:\155638\Basin Report\Mainstem_WY2000_Revised.xls 11/12/2001 11:44 AM) 1,000,000 100,000 Anatone, WA Hells Canyon Weiser, ID Dam King Hill, ID Murphy, ID Heise, ID 10,000 Milner Dam, ID Discharge (cfs) 1,000 100 10 900 800 700 600 500 400 300 200 100 River Mile Mean Max Discharge (cfs) NOTE: The period of record used for this figure is Technical Report E.1-2 Figure 4.2 Mean Annual Discharge (cfs) between water year 1926 and 2000 (Oct 1925 HELLS CANYON HYDROELECTRIC COMPLEX to Sept 2000) to represent post-regulation Mean Min Dsicharge (cfs) conditions following the completion of American Falls Reservoir in 1926. Comparison of Discharges Throughout Study Area An IDACORP Company WATERSHED PRODUCTION SEDIMENT ZONE 1 SOURCE AREA UPSTREAM CONTROLS (Climate, diastrophism, land use) TRANSFER ZONE 2 DOWNSTREAM CONTROLS (base level, diastrophism) DEPOSITION ZONE 3 SEDIMENT SINK DEPOSITIONAL AREA From Schumm 1977. Technical Report E.1-2 Figure 4.3 HELLS CANYON HYDROELECTRIC COMPLEX Key Fluvial Geomorphology Zones An IDACORP Company P:\155638\Graphics\Geomorphologyfigs.fh10 15-Dec-2001 This page left blank intentionally. Technical Report E.1-2 Figure 4.4 Study Area Vicinity Features Legend r MN GN HELLS CANYON HYDROELECTRIC COMPLEX Washington Idaho Montana Slope Classification 17 30' 0 08' 311 MILS Slope Classes less than 10 degrees 2 MILS Oregon 10 to 30 degrees Wyoming 30 to 40 degrees 30 0 30 60 Miles greater than 40 degrees UTM GRID AND 1987 Nevada Utah MAGNETIC NORTH DECLINATION AT CENTER OF OXBOW QUADRANGLE An IDACORP Company This page left blank intentionally. P:\155638\Graphics\Geomorphologyfigs.fh10 15-Dec-2001 (Source: P:\155638\Basin Report\Snake_profile.xls 08/24/2001 11:54 AM) 8000 7000 Jackson 6000 Heise 5000 Blackfoot Minidoka Milner 4000 Buhl 3000 King Hill Channel Elevation (ft) CJ Strike Murphy Nyssa Weiser 2000 Brownlee Dam Hells Canyon Dam Note: Elevations within the HCC are approximate. Salmon River 1000 Anatone Sources: USGS (1997a,b), IPC (2001b) 0 100 200 300 400 500 600 700 800 900 1000 River Mile above Mouth Technical Report E.1-2 Figure 4.5 HELLS CANYON HYDROELECTRIC COMPLEX Snake River Channel Profile An IDACORP Company P:\155638\Graphics\Geomorphologyfigs.fh10 17-Dec-2001 LEGEND: 52 mmh Reservoir bottom sediments Current bed subsurface g 27 mm c Current bed surface (armor) g 0.062-0.20 mm 54 mm c 20-250 mm Bonneville Flood boulders 1420 mma a O’Connor 1993 b Osterkamp 1997 c IPC 2001b Grande Ronde d USBR 1984 River e IPC 2000b f Emmett 1975 Hells Canyon g Jones and Seitz 1980 Salmon River h Asotin 2001 Burnt & HCC i USBR 2001 Powder Rivers <0.062 mmc Weiser River Payette 22 mmf River <0.062 mmd 23-26 mmb >40 mmb 22 mmb Malheur River 0.062 mmi Upper Snake River Boise River 17-25 mmb <100 mmb <16 mme 55 mme American 2160 mma Falls 340 mma CJ Strike Lake Walcott Owyhee River Technical Report E.1-2 Figure 4.6 HELLS CANYON HYDROELECTRIC COMPLEX SummarySummary of of Relative Relative Sediment Sediment Size Size DataData (d (d5050) )in in the the Study Study Area Area An IDACORP Company P:\155638\Graphics\Geomorphologyfigs.fh10 15-Dec-2001 (Source: P:\155638\Basin Report\Mainstem_WY2000_Revised.xls 11/12/2001 11:44 AM) 100,000 10,000 Payette River Boise River 1,000 Weiser River Owyhee River Malheur River 100 Discharge (cfs) 10 1 405 395 385 375 365 355 345 River Mile NOTE: Mean Max Discharge (cfs) Available data from the period following the Technical Report E.1-2 Figure 4.7 Mean Annual Discharge (cfs) last major storage facility (see Table 2.2) are HELLS CANYON HYDROELECTRIC COMPLEX used as the period of record for each major Mean Min Dsicharge (cfs) tributary upstream from HCC. Comparison of Discharges from Major Tributaries Upstream from the HCC An IDACORP Company 10000 Owyhee River 8000 Middle Fork Owyhee River North Fork Owyhee River 6000 West Little Owyhee River 4000 2000 Elevation (ft) 0 320 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0 River Mile (From Snake River, miles) 10000 Boise River Middle Fork Boise River 8000 North Fork Boise River 6000 South Fork Boise River 4000 2000 Elevation (ft) 0 320 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0 River Mile (From Snake River, miles) 10000 Payette River 8000 Middle Fork Payette River North Fork Payette River 6000 South Fork Payette River 4000 2000 Elevation (ft) 0 320 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0 River Mile (From Snake River, miles) 10000 Malheur River 8000 Little Malheur River ) North Fork Malheur River 6000 South Fork Malheur River 4000 2000 Elevation (ft) 08/23/2001 10:45 AM 08/23/2001 10:45 0 320 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0 River Mile (From Snake River, miles) 10000 Weiser River West Branch Weiser River 8000 East Fork Weiser River West Fork Weiser River 6000 Middle Fork Weiser River Little Weiser River 4000 Elevation (ft) 2000 0 320 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0 River Mile (From Snake River, miles) Technical Report E.1-2 Figure 4.8 HELLS CANYON HYDROELECTRIC COMPLEX Stream Profiles for Each of the Major Tributaries Upstream An IDACORP Company from the HCC P:\155638\Graphics\Geomorphologyfigs.fh10 15-Dec-2001 (Source: P:\155638\Basin Report\anthropogenic\Milner_Boise.xls Hypsometric Curve for Mainstem Snake River Basin 12000 Snake River Study Area 10000 8000 6000 Elevation (ft) 4000 2000 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent of Area Above Various Elevations Comparison of Hypsometric Curves for the Major Tributaries 12000 Owyhee River Basin Boise River Basin Malheur River Basin 10000 Payette River Basin Weiser River Basin 8000 6000 Elevation (ft) 4000 2000 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent of Area Above Various Elevations Comparison of Hypsometric Curves for Local Tributaries Within and Downstream from HCC 12000 Burnt River Basin Powder River Basin Imnaha River Basin 10000 Salmon River Basin Grande Ronde River Basin 8000 6000 4000 Elevation (ft) 2000 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent of Area Above Various Elevations Technical Report E.1-2 Figure 4.9 HELLS CANYON HYDROELECTRIC COMPLEX HypsometricSediment YieldCurves Computaion Schematic An IDACORP Company P:\155638\Graphics\Geomorphologyfigs.fh10 04-Jan-2002 \GIS\Hysometric curves.xls 8-21-2001 P:\155638\Graphics\Geomorphologyfigs.fh10 15-Dec-2001 (Source: P:\155638\Basin Report\Brownlee_inflow2.xls 11/15/2001) 40,000,000 35,000,000 30,000,000 25,000,000 20,000,000 15,000,000 Snake River Volume (acre feet) Snake River Volume 10,000,000 5,000,000 0 1993 1994 1995 1996 1997 1998 1999 2000 Water Year Estimated Unregulated Flow Technical Report E.1-2 Figure 4.10 Observed Regulated Flow HELLS CANYON HYDROELECTRIC COMPLEX Annual Unregulated versus Observed Inflow to Brownlee Reservoir: 1993-2000 An IDACORP Company P:\155638\Graphics\Geomorphologyfigs.fh10 15-Dec-2001 (Source: P:\155638\Basin Report\Brownlee_inflow2.xls 11/15/2001) 60,000 160,000 140,000 50,000 120,000 40,000 100,000 30,000 Flow Rate (cfs) 20,000 10,000 0 01-Oct-93 30-Nov-93 29-Jan-94 30-Mar-94 29-May-94 28-Jul-94 26-Sep-94 Technical Report E.1-2 Figure 4.11 HELLS CANYON HYDROELECTRIC COMPLEX Estimated Unregulated Flow Observed Regulated Flow Unregulated versus Observed Inflow to Brownlee Reservoir: Water Year 1994 An IDACORP Company P:\155638\Graphics\Geomorphologyfigs.fh10 15-Dec-2001 (Source: P:\155638\Basin Report\Brownlee_inflow2.xls 11/15/2001) 160,000 140,000 120,000 100,000 80,000 Flow Rate (cfs) 60,000 40,000 20,000 26-Sep-94 0 01-Oct-96 30-Nov-96 29-Jan-97 30-Mar-97 29-May-97 28-Jul-97 26-Sep-97 Technical Report E.1-2 Figure 4.12 HELLS CANYON HYDROELECTRIC COMPLEX Estimated Unregulated Flow Observed Regulated Flow Unregulated versus Observed Inflow to Brownlee Reservoir: Water Year 1997 An IDACORP Company P:\155638\Graphics\Geomorphologyfigs.fh10 15-Dec-2001 (Source: P:\155638\Basin Report\Mainstem_WY2000_Revised.xls 11/12/2001 11:44 AM) 100,00 0 10,000 Salmon River Grande Ronde River 1,000 Imnaha River Pine Creek Powder River Burnt River Wildhorse River 100 Discharge (cfs) 10 1 350 330 310 290 270 250 230 210 190 170 150 River Mile 26-Sep-97 Mean Max Discharge (cfs) Technical Report E.1-2 Figure 4.13 Mean Annual Discharge (cfs) HELLS CANYON HYDROELECTRIC COMPLEX Mean Min Dsicharge (cfs) Comparison of Discharges From Local Tributaries Within and An IDACORP Company Downstream from HCC This page left blank intentionally.