Benthic invertebrates and sediment characteristics in subtidal habitat at Rice Island, Columbia River Estuary, December 1991 and March 1992

The U.S. Army Corps of Engineers (COE) Portland District is responsible for annually dredging and disposing of more than 2 million yd³ (1.5 million m³) of bottom sediments from the navigation channel between River Miles (RM) 4.4 and 28.8 in the Columbia River estuary. Existing island and shoreline dredgedmaterial disposal sites are nearly filled to capacity, and options for new disposal sites for such large volumes of dredged material are extremely limited. One potential disposal site is the area just north of Rice Island, an island created with dredged material. Proposals for expanding Rice Island with dredged material include creating a 10,000-ft (3,048-m) by 500- to 1,000-ft (152- to 305-m) spit to the north of the present island. The south side of the proposed spit would be about 1,000 ft from the island, creating an island-spit configuration similar to that at Miller Sands, which is slightly upstream from Rice Island. Contract no. E96920018