The Dalles Lock & Dam Miter Gate Repair

Advanced American Construction (AAC) was contracted by the U.S. Army Corps of Engineers (USACE) to perform critical repairs during an emergency 29-day shutdown of the Dalles Navigation Lock. Originally planned as a 14-day routine maintenance closure, the shutdown was extended when USACE discovered structural cracks in the downstream miter gates during inspection. AAC mobilized quickly and worked 24/7 in two 12-hour shifts to complete the repairs on one of the busiest commercial river routes in the country.

The project scope included dewatering the lock, installing a 9-story stair tower, performing precision survey and laser scanning, and executing complex structural modifications to both gate leaves. AAC adjusted the tensioning of diagonal gate members using custom hydraulic wrenches, replaced worn J-bulb seals and sill beam seating angles, installed new shims under the miter blocks, and completed coatings repairs, all while working within theoretical design tolerances and uncertain alignment conditions. Despite pandemic-related supply chain and labor challenges, AAC delivered the work on schedule, allowing the lock to reopen without delaying river commerce.

The Dalles Lock & Dam is one of the ten largest hydroelectric dams in the U.S. and plays a vital role in the $23 billion Columbia River navigation system, which supports agricultural exports, heavy industry, and regional tourism.

Award: 2023 AGC Build America Award – Federal & Heavy Renovation