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: Truck loading facility Barge loading facility 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.