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HomeMy WebLinkAboutHydralic Design Data5 - HYDRAULIC DESIGN DATA 5.1 - River Flows (**) Watana Devil Canyon Average annual flow 8,050 cfs 9,160 cfs Maximum average monthly flow (June) 42,800 cfs 47,800 cfs Minimum average monthly flow (March) 570 cfs 660 cfs 5.2 - Design Flows (**) Probable Maximum Flood (Routed outflow): 302,000 cfs 351,000 cfs (Stage II) Derived from SSARR watershed model. (Stages I&II) 333,000 cfs (routed Reservoirs assumed at normal maximum 284,000 cfs through Watana operating level. (Stage III) Reservoir) (Stage III) 10,000 year flood inflow, derived from Gold Creek Station record routing through Watana not included in Devil Canyon estimate o Mean estimate 174,000 cfs 184,000 cfs 0 95% one-sided unner confidence limit 9-48 000 cfs 262,000 cfs Environmental Criteria: 1:50-year flood (routed). Derived from 34,000 cfs 42,000 cfs annual and summer flood series frequency analysis with normal generation assumed. Summer flood series controls design with full reservoir conditions in August and September. Diversion Design: 1:50-year flood inflow peak at Watana 89,500 cfs 43,300 cfs 1:25-year flood at Devil Canyon. Devil Canyon diversion assumes normal power operation and storage at Watana. 5.3 - Reservoir Levels (**) Normal Maximum operating level 2,000 ft MSL Normal Minimum Operating Level (Stages I&II) 1,455 ft MSL 2,185 ft MSL (Stage III) 1,850 ft MSL (Stages I&II) 1,405 ft MSL 2,065 ft MSL (Stage III) 851011 F-5-1 Maximum Reservoir Level Watana Routed PMF 2,017.1 ft MSL (Stages I&II) 2,199.3 ft MSL (Stage III) Environmental Surcharge Level 2,014.0 ft MSL (Stages I&II) 2,193.0 ft MSL (Stage III) Water Level for passing 10,000 year 2,014.3 ft MSL flood (Stages I&II) 2,193.3 ft MSL (Stage III) 5.4 - Reservoir Operating Rule (**) Watana 1:50-year surcharge level (1:50-year 2,014 ft MSL surcharge due to operating rule for restricted discharges and reduced (Stages I&II) nitrogen supersaturation.) 2,193 MSL Reservoirs allowed to surcharge (Stage III) before main spillway operation. 5.5 - Reservoir Data (**) Devil Canyon 1,465.6 MSL (Stage II) 1,463.1 ft MSL (Stage III) 1,456.0 ft MSL 1,456.0 ft MSL Devil Canyon 1,456 ft MSL Reservoir area at normal 20,000 acres 7,800 acres maximum operating level (Stages I&II) Reservoir Live Storage: (storage between normal maximum and minimum reservoir levels) Reservoir Total Storage: (at normal maximum operating level) 38,000 acres (Stage III) 2,400,000 acre-ft 350,000 acre-ft (Stages I&III) 3,740,000 acre-ft (Stage III) 4,400,000 acre-ft 1,100,000 acre-ft (Stages I&II) 9,470,000 acre-ft (Stage III) 851011 F-5-2