Alder Dam
- Year completed - 1945
- River system - Nisqually
- Original investment - $14.7 million
- Type of dam - concrete arch
- Height - above riverbed, 285 feet; above bedrock, 330 feet
- Length - 1,600 feet
- Width - top, 15 feet; base, 120 feet
- Volume of concrete in dam - 420,000 cubic yards
- Average flow - 1,400 cubic feet/second
- Drainage area - 286 square miles
- Reservoir length - 7 miles
- Miles of shoreline - 28 miles
- Reservoir area at maximum elevation - 3,065 acres
- Reservoir elevation - full, 1,207 feet; lowest allowable, 1,114 feet
- Average annual generation - 228 million kilowatt-hours
- Equivalent number of NW homes served - 16,000
- Number of generators - Two, 25,000 kilowatt
- Installed capacity (nameplate rating) - 50,000 kilowatts
LaGrande Dam
- Year completed - powerhouse, 1912; new dam, 1945
- River system - Nisqually
- Original investment - $9.7 million
- Type of dam - concrete gravity and embankment
- Height - above riverbed, 192 feet; above bedrock, 217 feet
- Length - 710 feet
- Width - top, 12 feet; base, 85 feet
- Volume of concrete in dam - 85,000 cubic yards
- Average flow - 1,400 cubic feet/second
- Drainage area - 292 square miles
- Reservoir length - 1.5 miles
- Miles of shoreline - 3.5 miles
- Reservoir area at maximum elevation - 45 acres
- Reservoir elevation - full, 935 feet; lowest allowable, 910 feet
- Average annual generation - 345 million kilowatt-hours
- Equivalent number of NW homes served - 24,500
- Number of generators - four 6,000 kilowatt generators; one 40,000 kilowatt generator
- Installed capacity (nameplate rating) - 64,000 kilowatts