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The Dalles Lock and Dam

Published Sept. 17, 2013
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The Dalles Lock and Dam is located 192 miles upstream from the mouth of the Columbia River.  It is one of the top ten largest hydropower dams in the United States!  In addition to supplying hydropower to the Pacific Northwest Region, The Dalles Dam provides a reliable water source for navigation, irrigation, flood mitigation and recreation.

The Powerhouse

Construction: began 1952

  • Units 1-14           Completed 1957 (Phase I)
  • Units 15-22         Completed 1973 (Phase II)

Turbine Generators:

  • Units 1-14  =       78,000 KW
  • Units 15-22  =     86,000 KW

Turbine/Generator Speed:

  • Units 1-14  =       85.7 rpm
  • Units 15-22  =     80 rpm

Generator Voltage:  13,800 volts

Transmission Voltage:

  • Line 1-2  = 115 KV
  • Lines 3-6  = 230 KV

Water discharge at 100% capacity: 312,000 cfs  = 2,333,922 g/s

Average yearly power produced: 8,961,000 MW

Fishway Units: 2, 3,500 KW each. Fish units are generators providing water outflow for fish ladders.

Total Cost at Completion:             $378 million

Total Generation Capacity:          2.1 million KW operating at 115%

 

Spillway

  • Overall length: (441 m) 1,447 ft
  • Width of gravity section: 239 ft  (72.8 m)
  • Tainter gates: 23 gates:   50 ft x  42.5 ft  (15.2 m x 13 m)
  • Design capacity: 2,290,000 cfs: 17,130,389 g/s

Pool elevation at sea level:

  • AVG: 158 ft (48 m)
  • MIN: 155 ft (47 m)
  • MAX: 161 ft (49 m)

Fish Ladders

Forebay water flow rate (volume):

  • North Ladder:    160 cfs
  • East Ladder:       140 cfs

 

Entrance water flow rate:

  • North Ladder:    1,200 cfs
  • East Ladder:       1,500 cfs

 

Ladder slopes: 1 on 16

Depth of ladders: 6 to 8 ft. (1.8 m to 2.4 m)

Width/Length:

  • North Ladder:    24 ft. x 1761 ft. (7.3 m x 536.8 m)
  • East Ladder:       30 ft. x 1801 ft.  (9.1 m x 549 m)

Navigation Lock

  • Fill / Empty time: 20 minutes to fill or empty
  • Width/Length: 86 ft. x 675 ft.; (26.2 m x 205.7 m)

Lift:

  • AVG: 88 ft. (26.8 m)
  • MIN: 84 ft. (24.3 m)
  • MAX: 90.5 ft. (27.6 m)
  • Depth Over Sill: 15 ft. minimum (4.6 m)

Average amount dispersed per lockage: 39,298,993 gallons

Average total lockages per day (2010): 6 commercial vessels

People often ask, “What does The Dalles mean?” The earliest origins of the word have been traced to French-Canadian voyagers who traded with the local Native American tribes. The word, dalle, was used to describe the natural geological features of this section of the river which reminded them of a gutter or trough. This is because the Columbia ran through stretches of narrow basalt rock cliffs at an amazingly swift pace. Eventually, these long and short narrows became known as The Dalles. 

Fish passage: elevation gained up the fish ladders ....... 88 ft. (26.8m)

The fish ladders are necessary so that adult fish can get past The Dalles Dam to return to their spawning grounds.

The best months to see fish climbing the fish ladders are:

  • Chinook Salmon: May - September
  • Coho Salmon: September - October
  • Sockeye Salmon: June and July
  • Steelhead Trout: September
  • American Shad: June and July
  • Lamprey: July and August

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