Merwin Dam (also known as Ariel Dam[3]) is a concrete arch gravity-type hydroelectric dam on the Lewis River, in the U.S. state of Washington. It is located on the border between Cowlitz County and Clark County. Its reservoir is called Lake Merwin.

Merwin Dam
LocationClark / Cowlitz counties, Washington, USA
Coordinates45°57′24″N 122°33′18″W / 45.95667°N 122.55500°W / 45.95667; -122.55500
Construction began1929
Opening date1931[1]
Operator(s)Pacificorp[1]
Dam and spillways
ImpoundsLewis River
Height313 feet (95 m)
Length1,250 feet (381 m)[1]
Reservoir
CreatesLake Merwin
Total capacity422,000 acre-feet (0.521 km3)[1]
Catchment area731 square miles (1,890 km2)[1]
Surface area3,921 acres (15.9 km2)[1]
Power Station
Commission date1931/1949/1958
Turbines3 x 45 MW Francis-type, 1 x 1 MW[2]
Installed capacity136 MW
Annual generation511,534 MWh

On November 24, 1971, the dam was fully lit allegedly giving the skyjacker D. B. Cooper an identifiable landmark when he jumped from a Boeing 727 passenger liner. Cooper had ransomed 200,000 dollars from Federal Authorities after holding hostage the 727 and its passengers in Seattle.[4]

References edit

  1. ^ a b c d e f Merwin Dam Archived 2011-07-16 at the Wayback Machine, NPDP Dam Directory
  2. ^ "Merwin Hydroelectric Project" (PDF). Final License Application. PacifiCorp. Archived from the original (PDF) on 7 August 2012. Retrieved 10 May 2012.
  3. ^ U.S. Geological Survey Geographic Names Information System: Merwin Dam
  4. ^ In Search Of..."D. B. Cooper" hosted by Leonard Nimoy, produced by Alan Landsburg c. 1979