Improving Maritime Safety

Building to Restore Marine Navigation

The mouth of the Colorado River is a federally authorized shallow draft navigation channel and has been plagued for more than 50 years by excess shoaling requiring frequent time consuming maintenance dredging. A sediment training structure constructed in the early 1980s was proving ineffective, and the impound area became over-burdened with sediment. This eventually led to the shoreline morphing over the years, allowing the river to take a sharp dog-leg turn to the west, making the inlet unnavigable by moderately sized vessels.

Project Details

To restore navigation in the channel we first built a new 2,750 foot jetty in three segments. The crown width of the jetty is 16 feet and the base varies in width from about 75 feet in the beach zone to about 120 feet at the seaward end. Core stone varying in weight from 200 to 2,000 lbs provide a rigid core with armor cover stone composed of cut blocks of granite, ranging in weight from 10 to 16 tons.

After the jetty was constructed, we dredged an estimated 416,000 cubic yards of sediment using a 400 horsepower submersible pump suspended from a crane mounted on a 150 foot spud barge. The existing grades in the channel alignment varied from +2 feet Mean Low Tide (MLT) to -15 feet MLT. The file profile was -15 feet MLT.