Silver Lake Dam
RIZZO was retained in 2005 on behalf of the Upper Peninsula Power Company (UPPCO), to provide technical support and consultation related to the rebuild of the Silver Lake Dam on the Dead River, in Marquette, Michigan. The Dam impounded Silver Lake Reservoir, which was a storage basin for two downstream hydroelectric installations operated by UPPCO.
The Dam sustained a catastrophic failure in May of 2003. The activation event drained approximately 25,000 acre feet of water from the impounded Silver Lake reservoir. RIZZO performed a field and geotechnical investigation and hydraulic modeling. After review of alternatives and costs, a decision was made by UPPCO to proceed with the rebuilding. RIZZO was responsible for preparing the detailed design, as well as the ER Report required by the Federal Energy Regulatory Commission (FERC).
RIZZO Responsibilities under the ER task included participating in strategy and agency meetings, developing and managing the implementation of the project's environmental strategy and program needs, and providing senior technical review. The ER involved identifying, reviewing, and documenting the currently known and available environmental, engineering, recreational, cultural, and socio-economic information related to the planned project and local region that may be impacted. Additional field studies were performed by RIZZO-managed and directed subcontractors to address possible impacts to wetlands, cultural and archeological resources, and identification of rare, threatened, or endangered species possibly present in the project area for the proposed rebuild project. This task included participating in strategy and agency meetings, developing and managing the implementation of the project's environmental strategy and program needs, and providing senior technical review.
RIZZO developed calculations and design methodologies to reduce the overall length of the spillway. Final design had to address impact on environment, hydro power output, construction cost, and regulatory compliance. RIZZO engineers balanced competing factors to develop a cost-effective design that satisfied Owner's objectives. The final result was a 35% reduction in the length of the spillway. The goal of the construction was to restore the Silver Lake Reservoir and upgrade the Dam to meet all current FERC guidelines.
RIZZO's close interaction and positive relationships resulted in a nine-month reduction of time in the schedule for the necessary environmental approvals required for construction. After receiving FERC approval, construction began June 2008 and was substantially complete by December 2008.
The Silver Lake project highlights RIZZO's experience with the following deliverables:
- Earth Embankment Soil Stability Analysis
- Hydrologic & Hydraulic Analyses
- Seepage Analysis
- Potential Failure Modes Analysis
- Comprehensive Geological and Geotechnical Investigations
- Design Plans and Specifications for modifications
- Drafting Services
- Develop/revise procedures for implementing emergency preparedness programs and activities
- Formal, Intermediate, Emergency, and Special Dam Safety Inspections
- Project Management