Sanford DamThe Sanford Dam is located on the Tittabawassee River approximately 11 miles upstream of Midland, Michigan. It is the most downstream of the four dams. The Sanford Dam was built to provide water level control for the purpose of hydro-electric power generation and received its original license from FERC in 1987. On May 19, 2020, the Sanford Dam was overtopped by increased flow from the upstream Edenville Dam breach. This led to the Sanford Dam failure. |
Restoration Progress
May 22, 2020
June 8, 2022
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December 11, 2020
August 19, 2022 |
Photo courtesy of Jordan Mowbray's video (click the image to watch)
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Quick Facts
$70.8 million |
944 |
2025 |
$115 - $460* |
Cost to Repair |
Waterfront Properties |
Estimated Lake Return Date |
Estimated Annual Capital Assessment |
*Capital Assessment estimates are subject to variation of +/- 30% because of cost sensitivities such as construction costs, the financing term and interest rates.
Sanford Dam will require demolition of the existing gated spillways and powerhouse and construction of new primary and auxiliary spillways.
Sanford Dam will require demolition of the existing gated spillways and powerhouse and construction of new primary and auxiliary spillways.
Long-Term Restoration
Critical items
Spillway Adequacy
- Sanford is classified a high hazard dam. Prior to May 2020 flood, the total spillway capacity was approximately 36,000 cubic feet per second (cfs) before water would begin overtopping embankments
- Prior State of Michigan 1/2 PMF was 37,000 cfs
- Based on current on-going studies and recent flood, this will increase
- FLTF study currently estimating future spillway requirement being 47,500 cfs
- Spillway requirements still being finalized based on
- PMP and PMF studies
- Inflow Design Flood Study
- State of Michigan Dam Safety Task Force
- EGLE approval
- The right embankment breached
- Reconstruct right embankment to meet stability criteria with seepage cutoff wall and internal drainage layers to protect against seepage-induced internal erosion
- Replace existing Tainter gates with Crest Gates to increase spillway
- Construct new auxiliary spillway to increase spillway capacity
- Geotechnical investigations and structural analyses are required to support design of new embankments and repair of existing embankments
- All water retaining structures will need to be thoroughly evaluated and designed to meet State and federal dam safety standards
Risk-based design approach
- The IDF/risk-based approach aligns with FEMA guidelines and recommendations of the Michigan Dam Safety Task Force guidelines for Michigan dams
- Inflow Design Flood that requires these steps:
- Site-specific Regional Probable Maximum Precipitation (PMP) studies which are underway.
- Perform downstream inundation mapping assuming dam failure for a range of flows starting from the 100-year flood up to the PMF
- Determine the incremental hazard increase and consequences of failure for a range of flood flows up to the PMF
- Use risk-based, IDF approach to inform the design spillway capacity – no less than 200-year but possibly less than the ½ PMF
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Contacts
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