Lower Monumental Dam and Lake Herbert G. West

Project Description

• Stream: Snake River
• Location: Matthaw, Washington
• Type of Project: Run-of-river
• Authorized Purpose: Power, Navigation
• Other Uses: Fishery, Recreation, Irrigation, Water Quality

Hydrologic Data

• Drainage area = 103,200 sq mi
• Maximum historical peak discharge:
       Unregulated = 409,000 cfs (1894)
       Regulated = 295,000 cfs (1894)
• Lake Elevation
       Maximum pool = 548.3 ft
       Normal pool = 540.0 ft
       Minimum pool = 537.0 ft
• Maximum rate of change per hour = 70,000 cfs

Powerhouse

• Number of units..........................6
• Nameplate capacity....................810 MW
• Overload capacity......................930 MW
• Hydraulic capacity.....................130,000 cfs