US Army Corps of Engineers

Lower Granite Dam and Lake

Provisional Data Warning
Hydrologic Data: [Hourly] [Tailwater] [8 Days Hourly] [Daily] [Prior Month] [Query]
Water Quality Data: [High 12-hour Avg TDG] [Total Spill] [TDG graphs] [TDG csv] [Temperature String] [Spillbays] [Forebay] [Tailwater]
Power: [Monthly Power Report]
Lower Granite Dam 1 Lower Granite Dam 2

Project Description

  • Stream: Snake River
  • Location: Almota, 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)
  • Forebay Elevation (NGVD29)
    Maximum pool = 746.5 ft
    Normal full pool = 738.0 ft
    Normal minimum pool = 733.0 ft
  • Maximum rate of change per hour = 70,000 cfs

Powerhouse

  • Number of units = 6
  • Nameplate capacity = 810 MW
  • Overload capacity = 932 MW
  • Hydraulic capacity = 130,000 cfs

7 Day Project Status

Drag to select region -

BUILDING STRONG®
U.S. Army Corps of Engineers, Columbia Basin Water Management Division
Email: Information Provider | Webmaster