Lower Monumental Dam - Hydroelectric Project Information

General Information

Dam:
Lower Monumental Dam. Snake River. River Mile 41.6
Constructed1:
1969 (units 1-3); additional units 4-6 completed in 1981
Owner:
U.S. Army Corps of Engineers, Walla Walla District
Normal Operating Pool2:
537.0-540.0 feet
Maximum Pool2:
548.3 feet
Powerhouse Capacity:
Nameplate capacity: 6 @ 135 MW, 810 MW total
Overload capacity: 6 @ 155 MW, 930 MW total
Hydraulic capacity: 130 kcfs
Spillway1:
572 feet, 8 gates

1 From USACE Walla Walla District, Digital Project Notebook Data Sheet.
2 From USACE Walla Walla District, Digital Project Notebook Structural Details Map.

Additional Information

Lower Monumental Dam web page. Contact U.S. Army Corps of Engineers, Walla Walla District for all additional information.

Lower Monumental Dam image
Aerial view of Lower Monumental Dam and navigation lock. Image Source: USACE Digital Visual Library. Image File Number: 4414-50. Photographer: Unknown. Date: Unknown.

These web pages provide information about the location, construction date, pool elevation, and powerhouse capacity of the major federal and non-federal hydroelectric projects in the Columbia Basin. All information is courtesy of U.S. Army Corps of Engineers, NWD unless otherwise noted. The information and images are from the Army Corps of Engineers 1989 publication, "Columbia River and Tributaries Review Study: Project Data and Operating Limits" unless otherwise noted. USACE makes no warranties concerning the accuracy, reliability, or suitability of the data for any particular purpose. Pages include links to the owners/operators hydroelectric project web sites with visitor/tour information and further information. The map and these web pages cover only the major federal and non-federal dams in the region.

Photos presented on these pages of the individual hydroelectric projects have been provided by various sources. Images from USACE Digital Visual Library are Public Domain images and have been cleared for public release. The USACE provides them for your use for free. Where appropriate, please give credit to "US Army Corps of Engineers." Use of all other images should be cleared through the image provider.

Columbia Basin Research provides these web pages for informational purposes only. Columbia Basin Research is not affiliated with any hydroelectric project. Please contact the Owner/Operator for questions about operations, tours, and any other matter.