Pertinent Data
| General | ||
| State | Washington | |
| County | Franklin and Walla Walla | |
| River | Snake | |
| River Mile | 9.7 | |
| Drainage area above Ice Harbor Dam, square miles | 109,000 | |
| Owner | U.S. Army Corps of Engineers, Walla Walla District | |
| Authorized Purposes | Power Generation and Inland Navigation | |
| Other Uses | Fishery and recreation | |
| Type of Project | Run-of-river | |
| Real Estate: | ||
| Fee acquisition land above pool elevation 440, acres | 7,830 | |
| Reservoir | ||
| Name | Sacajawea | |
| Elevations (Feet Mean Sea Level) | ||
| Maximum at dam for spillway design flood Normal operating range gauged at dam |
446.4 437 to 440 | |
| Length, miles | 31.9 | |
| Average width, miles | 0.4 | |
| Maximum width, miles | 1.0 | |
| Surface area at elevation 440 (low flow-flat pool), acres | 8,375 | |
| Storage between elevation 437 and 440 (acre feet) | 24,900 | |
| Dam (General) | ||
| Powerhouse, overall length | 671 | |
| Spillway, total length | 590 | |
| Navigation lock, overall width | 173 | |
| Concrete non-overflow sections: | ||
| Navigation lock to spillway (length, feet) Spillway to powerhouse (length, feet) Powerhouse to south shore embankment (length, feet) Earth embankment, north shore (length, feet) |
154 40 560 624 | |
| Total length of dam (feet) | 2,822 | |
| Maximum height of concrete sections (foundations deck, feet) | 213.0 | |
| Maximum height of abutment section (north shore foundation to top) | 123.0 | |
| Deck elevation | 453 feet msl | |
| Spillway | ||
| Type | Ogee, concrete, gravity, gate controlled | |
| Maximum width at base, elevation 392 feet msl (feet) | 139 | |
| Maximum height, foundation to deck (feet) | 141 | |
| Number of bays | 10 | |
| Overall length, feet (abutment centerlines) | 590 | |
| Clear length, feet | 500 | |
| Crest elevation, feet msl | 391 | |
| Gate seal elevation, feet msl | 389.07 | |
| Top of gate in closed position, elevation | 442 | |
| Deck elevation feet msl | 453 | |
| Gate lip elevation at maximum opening, feet msl | 436 | |
| Control gates: | ||
| Type Size Method of operation |
Tainter 50'W x 52.9'H individual electric hoists, remote and manually controlled | |
| Maintenance closure for spillway bays | Stoplogs | |
| Spillway design flood: | ||
| Peak discharge Pool elevation, feet msl Tailwater elevation, feet msl Gross head, feet |
850,000 cfs 446.4 374.0 72.4 | |
| Maximum flood at normal pool, elevation 440 | ||
| Discharge Tailwater elevation, feet msl Gross head, feet |
685,000 cfs 370.5 72.4 | |
| Stilling Basin | |
| Type | Horizontal apron |
| Width, perpendicular to flow, fee | 590 |
| Length, parallel to flow, feet | 168 |
| Floor elevation, feet msl | 304 |
| Height of continuous end sill, feet | 12 |
| Powerhouse | ||
| Number of generating units | 6 | |
| Spacing, feet: | ||
| Units 1 through 5 Unit 6 | 90 96 | |
| Erection and service bay | 110 | |
| Turbines: | ||
| Type | Kaplan, 6-blade | |
| Runner diameter: | ||
| Units 1 through 3, inches Units 4 through 6, inches | 280 300 | |
| Revolutions per minute: | ||
| Units 1 through 3 Units 4 through 6 |
90.0 87.5 | |
| Generators: | ||
| Rating (nameplates): | ||
| Units 1 through 3, kilowatts Units 4 through 6, kilowatts | 90,000 111,000 | |
| Power factor | 0.95 | |
| Kilovolt ampere rating: | ||
| Units 1 through 3 Units 4 through 6 |
95,000 117,000 | |
| Units installed complete initially | 3 | |
| Skeleton units provided initially | 3 | |
| Total units now installed | 6 | |
| Plant capacity, nameplate rating, kilowatts | 603,000 | |
| Crane capacities, tons: | ||
| Intake (joint use with spillway Bridge Draft tube gantry |
85 500 35 | |
| Navigation Lock and Channels | ||
| Type | Single lift | |
| Net clear length, lock chamber, feet | 675 | |
| Net clear width, lock chamber, feet | 86 | |
| Minimum water depth over lower sill, feet | 16 | |
| Upstream gate: | ||
| Type Height, feet | Radial 25 | |
| Downstream gate: | ||
| Type Height, feet | Vertical lift 91.0 | |
| Maximum operating lock lift, feet | 105 | |
| Length of guidewalls (from face of gate), feet: | ||
| Upstream (floating) Downstream | 746 696 | |
| Normal fill time | 11 minutes | |
| Normal emptying time | 14 minutes | |
| Fish Facilities | ||
| Number of fish ladders | 2 | |
| Slope: | ||
| North Shore South Shore | 1V on 10H 1V on 16H | |
| Number of weirs (including orifice-control section) | 103 | |
| Overflow weirs: | ||
| Number Height Orifice size: | 97 6 feet | |
| North Shore South Shore |
18 x 18 inches 21 x 23 inches | |
| Exit of ladders, invert elevation, feet msl | 431 | |
| Entrance of ladder, invert elevation, feet msl | 332 | |
| Normal fishway flow, forebay to each ladder: | ||
| North Shore, cfs South Shore, cfs |
74 142 | |
| Ladder, clear width: | ||
| North Shore, feet South Shore, feet |
16 24 | |
| Pumps for fish attraction water: | ||
| Number: | ||
| North Shore South Shore | 3 8 | |
| Type | Turbine | |
| Discharge: | ||
| North Shore, cfs South Shore, cfs |
250 300 | |
| Fishway entrances: | ||
| North shore South shore Non-overflow |
2 3 3 | |
| Powerhouse collection system: | ||
| Number of orifice entrances Length of channel, feet Width of channel, feet | 12 661 17.5 | |
| Downstream Migrants Bypass System: | ||
| Ice-and-trash sluiceway Hydraulic capacity, cfs |
1 2,700 | |
| Hydrologic
Data (Based on streamflow data for the Snake River near Clarkston, Washington) | ||
| Drainage area, square miles | 103,200 | |
| Period of record | Oct 1915 to Sept 1972 (Discontinued in Dec 1972) | |
| Discharges in cubic feet per second: | ||
| Instantaneous maximum of record, 29 May 1948 Instantaneous minimum of record, 2 Sep 1958 Average annual flow Average annual mean daily peak flow |
369,000 6,660 48,840 188,300 | |
| Extreme outside period of record: | ||
| Flood of June 1894 Flood of June 1894, controlled by existing projects | 409,000 295,000 | |
| Standard project flood (controlled by existing projects): | ||
| Snake River below Clearwater River Snake River above Clearwater River Clearwater River above Snake River |
420,000 295,000 150,000 | |
| Spillway design flood | 850,000 | |