Mayfield Forebay Dam, located on the Cowlitz River in Lewis, Washington, stands as a testament to engineering excellence with its primary purpose of hydroelectric power generation.
Wind
Humidity
Built in 1963 by the Harza Engineering Co., this concrete gravity dam reaches a height of 47 feet and serves as a vital component in the region's water resource management system. With a normal storage capacity of 133,718 acre-feet and a maximum storage of 184,194 acre-feet, the dam plays a crucial role in supplying water for both hydroelectric power generation and recreational activities.
The dam, with a multi-arch core type and resting on a rock foundation, boasts a hydraulic height of 44 feet and a structural height of 63 feet. Though classified as having a low hazard potential, the risk assessment for the dam indicates a high risk level (2). Despite this, the condition assessment is currently not available, prompting the need for updated risk management measures. Managed by the Federal Energy Regulatory Commission, the dam undergoes regular inspections, with the last one conducted in September 2020. Additionally, emergency action plans are in place, ensuring preparedness in case of unforeseen events.
Mayfield Forebay Dam's strategic location and design make it a vital component in the water resource infrastructure of the region, contributing significantly to both power generation and water supply. As a key feature along the Cowlitz River, the dam continues to play a crucial role in supporting various activities while ensuring the safety and stability of the surrounding areas. With its rich history and impressive specifications, the Mayfield Forebay Dam stands as a symbol of sustainable water management practices in the face of changing climate conditions.
Year Completed |
1963 |
Dam Length |
112 |
Dam Height |
47 |
River Or Stream |
Cowlitz River |
Primary Dam Type |
Concrete |
Surface Area |
2250 |
Hydraulic Height |
44 |
Drainage Area |
1392 |
Nid Storage |
184194 |
Structural Height |
63 |
Hazard Potential |
Low |
Foundations |
Rock |
Nid Height |
63 |
| Location | Reservations | Toilets |
|---|---|---|
Mayfield Lake - Tacoma Power
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Ike Kinswa State Park
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Mossyrock Park - Tacoma Power
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Main Campground
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S'mores Loop
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Kid Valley Campground
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