Pertinent Data
General | ||
Location: | ||
State County River River Mile |
Washington Columbia and Whitman Snake 70.3 | |
River miles upstream from Ice Harbor Dam | 28.7 | |
Owner | U.S. Army Corps of Engineers, Walla Walla District | |
Authorized Purpose | Power generation and inland navigation | |
Other Uses | Fishery and recreation | |
Type of Project | Run-of-river | |
Real Estate: | ||
Fee acquisition land above pool elevation 638, acres | 11,179 |
Reservoir | ||
Name | Lake Bryant1 | |
Elevations (Feet Mean Sea Level): | ||
Maximum at dam for spillway design flood Normal operating range gauged at dam |
646.5 638 to 633 | |
At Pool Elevation 638: | ||
Length, miles Length of shoreline, miles Average width, miles Maximum width, miles Surface area (low flow, 30,000 cfs or less), acres |
37.2 92 0.4 0.8 10,025 | |
Storage below elevation 638 (low flow), acre-feet | 565,200 | |
Storage below elevation 633 (low flow), acre-feet | 516,300 | |
Storage between elevations 633 and 638 | 48,900 | |
Height normal high pool elevation 638 to tailwater elevation 540 (low flow, 30,000 cfs or less), feet | 98 |
Dam (General) | ||
Axis (Lambert) | N 10° 57'W | |
Length and Widths, feet: | ||
Dam total length at crest North abutment embankment North non-overflow monoliths length Spillway overall length (between abutment centerline) Spillway to powerhouse non-overflow Powerhouse overall length Powerhouse to navigation lock non-overflow length Navigation lock overall width |
2,655 878.5 189 512 48.5 656 57 328 | |
Concrete Heights, feet: | ||
Maximum overall concrete height (powerhouse sump deck to deck) Maximum non-overflow monoliths height (north) Maximum lock wall monolith height (culverts to deck) |
253 200 165 | |
Deck elevations, feet msl | ||
Intake, spillway bridge, non-overflow sections, and upstream end of
navigation lock Downstream end of navigation lock South shore fish ladder Tailrace and fishwater intake North abutment embankment |
651 646 558 558 656 |
Spillway | ||
Number of Bays | 8 | |
Overall length, feet (abutment centerlines) | 512 | |
Deck elevation, feet msl | 651 | |
Ogee crest elevation, feet msl | 581 | |
Flip lip elevation | 532 | |
Control gates: | ||
Type Size | Tainter 50'W x 60'H | |
Gantry crane (joint use with powerhouse) capacity, tons | 100 | |
Stilling basin length, feet | 118 | |
Stilling basin elevation, feet msl | 466.5 | |
Maximum design capacity, cfs | 850,000 |
Powerhouse | ||
Length overall, feet | 656 | |
Spacing, feet: | ||
Units 1 through 5 Unit 6 Erection and service bay |
90 96 110 | |
Width overall, transverse section, feet | 243 | |
Maximum height (draft tube invert to intake deck), feet | 226 | |
Turbines: | ||
Type Runner diameter, inches Revolutions per minute Rating horsepower Distributor centerline elevation |
Kaplan, 6-blade 312 90 212,400 501 | |
Generators: | ||
Rating (nameplates), kilowatts Power factor Kilovolt ampere rating |
135,000 0.95 142,100 | |
Units installed complete initially | 3 | |
Skeleton units provided initially | 3 | |
Total units now installed | 6 | |
Plant capacity, nameplate rating, kilowatts | 810,000 | |
Crane capacities, tons: | ||
Intake (joint use with spillway) Bridge Draft tube gantry |
100 600 50 |
Navigation Lock and Channels | ||
Net clear length, lock chamber, feet | 668 | |
Net clear width, lock chamber, feet | 86 | |
Operating water surface elevations in chamber | 537 to 638 | |
Maximum operating lock lift, feet | 101 | |
Upstream gate: | ||
Type Height, feet | Submersible tainter 22 | |
Downstream gate: | ||
Type Height, feet | Miter 85 | |
Length of guidewalls (from face of gate), feet: | ||
Upstream (floating) Downstream | 665 700 | |
Downstream approach channel: | ||
Width, feet Bottom elevation | 250 521 | |
Lower lock sill elevation, feet | 522 | |
Upper lock sill elevation, feet | 618 | |
Maximum depth over sills, feet | 20 | |
Minimum depth over sills, feet | 15 |
Abutment Embankment | ||
Embankment elevation | 656 | |
Embankment top width, feet | 43 | |
Material | Gravel ill with rock facing impervious silt core | |
Upstream Downstream | Combination sand and gravel
filters Gravel and sand filters | |
Slope, upstream | 1V on 2H | |
Slope, downstream | 1V on 2H |
Fish Facilities | ||
Upstream migrants fish ladder: | ||
Number of fish ladders Slope Ladder clear width, feet Design capacity, cfs | 1 1V on 10H 20 75 | |
Exit Channel: | ||
Location Top of trashrack elevation Invert elevation Width |
Between weir 637 and pool in non-overflow section 632 627 6 feet | |
Normal operating range: | ||
Pool elevations Tailwater elevations Riverflow |
633 to 638 537 to 544 0 to 225,000 cfs | |
Maximum operating range: | ||
Pool elevations Tailwater elevations Riverflow |
632 to 639 537 to 547.5 0 to 340,000 cfs | |
Pumps for fish attraction water: | ||
Number Rated capacity, cfs | 3 2,550 | |
Downstream migrants: | ||
Traveling fish screens Fingerling collection gallery Fingerling transportation pipe Fingerling handling facility Fingerling transportation facilities:
Design pool range |
18 1 1 1 1 1 633 to 638 |
Hydrologic Data (Based on streamflow data for the Snake River near Clarkston, Washington) | ||
Drainage area, square miles | 103,200 | |
Period of Record | October 1915 to September 1972 (Discontinued in December 1972) | |
Discharges, cfs: | ||
Instantaneous maximum of record, 29 May 1948 Instantaneous minimum of record, 2 September 1958 Average annual flow Average annual mean daily peak flow |
369,000 6,660 50,300 188,300 | |
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 |
1For the purpose of continuity with existing Little Goose Lock and Dam documents, the use of the term "pool" or "reservoir"
is used interchangeably. The term "lake" is used only to designate a geographical body of water.