Summary:

The project involved constructing a labyrinth spillway dam in the Maquoketa River to restore the former Lake Delhi. The scope included several key components:

• Temporary Coffer Dam: Designed and installed to shield the construction site from upstream and downstream water flows.
• Groundwater Dewatering System: Designed and installed to lower the water level at the construction site.
• Embankment Fill: Over 20,000 cubic yards of glacial till were used to support the concrete dam.
• Sheet Pile Installation: 24,000 square feet of sheet piling were installed to block water flow below the new dam.
• Concrete Spillway/Dam: Constructed using more than 6,000 cubic yards of concrete and nearly 1 million pounds of reinforcing steel.
• Site Improvements: Included an observation patio, a parking lot, and perimeter fencing with gates.

The project was completed in just over one year from start to finish.