BIRCH LAKE DAM

Services Categories: 
Location: 
Lake County, MN
Completed: 
2009-2014

· Dam Built in 1950s

· 5 Stop Log Gates

· 4 Sluice Gates

· 9 Foot Head

· 226 Foot Long Dam

AMI Consulting Engineers, PA assisted Minnesota Power in stabilizing and maintaining functions of the Birch Lake Dam.  This work included the design of anchor wall repairs to stabilize a section of wood crib to allow for proper gate lifting operations.  The new stabilization system consisted of a new concrete anchor wall, tie rods and spreader plates through the crib that allow the client to manually adjust to maintain proper clearances and proper gate operation.  AMI assisted with the construction management through field inspections during construction.  AMI has recently performed timber crib inspections and tainter gate inspections to ensure safe working operations of the dam.  The outcome of these inspections have led to continued work on the dam that have included complete load determination on existing steel and wood members due to ice and impact loading, global stability analysis of the dam, replacement of critical overstressed members and design for complete replacement of the entire dam with new reinforced concrete.  Included in this final design is the upgrade to the tainter gates, trunnion bearings, trunnion supports and lifting systems.  All work was scheduled for a phased replacement and completed over two seasons.  The upgrades to the most recent codes and safety standards will allow the dam to be operated at full capacity without the need for additional costly repairs or stabilization.  

In addition to the above services, AMI assisted with construction inspections, shoring design, form work inspections, portable dam reconditions and approvals, and providing field assistance in completing the project.  AMI has prepared complete plans, specifications, and complete calculations for Federal Energy Regulatory Commission review and approval prior to the construction activities being authorized.