News Story Manager

Channel dredging benefits coastal marsh

Los Angeles District
Published March 1, 2013
This graphic shows the channels within the Santa Ana River marsh where contractor CJW will remove nearly 73,000 cubic yards of material to restore channel depth, tidal flow and improve water quality.

This graphic shows the channels within the Santa Ana River marsh where contractor CJW will remove nearly 73,000 cubic yards of material to restore channel depth, tidal flow and improve water quality.

White poles mark the edge of the channels to indicate areas from which CJW will dredge material. Red flags indicate sensitive marsh areas for heavy equipment to avoid. Equipment in the background is in the process of removing material and placing it into trucks for transportation to upland disposal sites.

White poles mark the edge of the channels to indicate areas from which CJW will dredge material. Red flags indicate sensitive marsh areas for heavy equipment to avoid. Equipment in the background is in the process of removing material and placing it into trucks for transportation to upland disposal sites.

NEWPORT BEACH, Calif. – Over the past couple decades, material accumulating near the mouth of the Santa Ana River has impacted an adjacent marsh, limiting its tidal flow, reducing water quality and threatening nesting habitat for endangered and threatened species. A Los Angeles District Army Corps of Engineers project underway will not only remedy those conditions, but also provide material to renourish a nearby section of coastline.

CJW Construction, Inc., of Santa Ana, began removing nearly 73,000 cubic yards of sediment in the southern channels of the 92 acre marsh in January. The work will restore the design depth of channels in the marsh, restoring tidal circulation and improving water quality.

The primary beneficiaries of the work will be endangered species, such as the light-footed clapper rail and the Belding’s savannah sparrow, for which the marsh provides nesting habitat. Restoration of marsh channels to design depths will remove sandy shoals and prevent the transition of intertidal marsh habitats, while also supporting the overall health of the coastal salt marsh ecosystem through improved circulation.  In addition, the project will remove weedy vegetation from an adjacent island to restore nesting habitat for the federally endangered California least tern.

Material removed from marsh channels will end up in two places. About 23,000 cubic yards of material is compatible with local beach sand and will be deposited in about 800 feet of water about a half mile south of the river mouth to provide beach nourishment for local beaches eroded by littoral processes. The remaining 50,000 cubic yards of material that is not compatible for nearshore disposal will be placed at an approved upland disposal site.

CJW anticipates completing the dredging and removing its equipment by late March or early April and will restore the site to pre-project conditions.