Delta Coves at Bethel Island was one of the largest residential developments built in Northern California during 2006-2008. The 320-acre residential waterfront community includes 494 lots, 19 streets, and a marina.
The scope of work included 6 million cubic yards of excavation, 2 million square feet of deep dynamic compaction, the installation of 600,000 square feet of stone columns, and the construction of 14,000 linear feet of slurry wall. Additionally, the project involved the placement of 225,000 tons of riprap, along with 20,000 tons of asphalt paving. This unique project had many challenging aspects, including the requirement that no sub-surface water could leave the site unless it had been treated by reverse osmosis. Going above and beyond the ongoing dewatering efforts, GBI developed an innovative plan using coffer dams and lagoons to create detention basins, which eliminated the need for reverse osmosis. This creative solution saved the owner $15 million.
Additionally, the use of cutting-edge GPS technology in multiple phases of this project ensured the efficient and precise movement of dirt and placement of materials. This project was completed ahead of schedule and well under budget.