Representative Projects: Dams & Levees :

Montezuma Wetlands Marsh Restoration - The marsh restoration involves raising the existing ground surface grades to convert approximately 1,800 acres of reclaimed farmland into tidal and seasonal wetlands.  The project site is located south of Fairfield and northeast of Suisun Bay, at the eastern edge of the Suisun Marsh at the confluence of Montezuma Slough and the Sacramento River.

The Project is permitted to use sediment dredged from the San Francisco Bay-Delta system for fill. The dredge material arrives by barge at a transfer station approximately 2.5 miles from project area. At the transfer station, the dredged materials are mixed with water to create a slurry that is pumped to the fill area. Approximately 17 million cubic yards of sediment will be used to raise the surface of the site to elevations suitable for tidal marsh restoration.

Hultgren-Tillis Engineers developed schemes for constructing the core of the levees using light weight peat materials and using heavier mineral soil fills to create stability berms and a shell over the lighter peat materials. They established a fill thickness control system to optimize of material placement without impacting the levee stability.