Case study · Private lake, Michigan
Mirror Lake: A Dead Lake Brought Back to Life
Two projects, one lake: hydraulic dredging to restore depth, then a full rebuild of the failing dam that holds it.
- Lake size
- 12 ac
- Dredged
- ~50,000 yd³
- Spoils pond
- 4.5 ac
- Sheet-pile core
- 300 ft
Part 1 · Lake restoration
Hydraulic Dredging
Problem: A 12-acre private lake, created by a dam in the 1940s, had filled with silt. It was useless for fishing or recreation.
Solution: We ran sediment testing to get an EGLE permit, built a 4.5-acre spoils retention pond in a farm field about ½ mile away, and brought in our dredge with a booster pump. We hydraulically dredged about 50,000 yd³ to the pond, then removed the dredge and pipeline.
Result: The lake was ready for boating right away. It was stocked with native trophy fish species and is now a growing, high-quality fishery.
Part 2 · Infrastructure
Dam Rebuild
Problem: The earthen dam was built in the 1940s, failed in the 1960s when a storm overtopped it, and was then rebuilt poorly. It was leaking again, and engineers judged it close to failure. That put homes downstream and a major highway bridge at risk of flooding.
What we did:
- 1Our engineers prepared the design and permit drawings. Because of the risk, EGLE issued the permit fairly quickly.
- 2We fused and installed two 12″ × 150′ HDPE siphons, with fish screens and control valves, to lower the lake about 5′.
- 3We drove 300 linear feet of heavy sheet piling down the dam's center (projected 120-year life).
- 4We built a new adjustable sheet-pile spillway and removed the old concrete one. Setting the top at the maximum overflow level let it serve as the emergency spillway too, which saved the owner a separate structure.
- 5We raised the downstream driveway about 5′ and installed a box culvert sized for major storms, replacing two undersized, failing culverts.
- 6While the water was down, a long-reach excavator recontoured the shoreline for walking and fishing access. Then we refilled the lake and seeded the site with native grasses.
Watch the Dredge at Work
Video plays from YouTube when you press play.
Project Photos
Get the full project file (PDF)
Both phases, step by step, with numbers and photos. Great for lake boards and associations.