J.E. McAmis, a Chico based heavy civil marine contractor, has won the Tillamook North Jetty Repair Project.
The scheme is located at the north end of Tillamook Bay on the Oregon Coast, about 47 miles south of the mouth of the Columbia River.
Tillamook Bay is a tidal estuary about 6 miles long, north to south, and a maximum of 3 miles wide. Five major rivers flow into Tillamook Bay. The ocean entrance to the bay is located at its northern end and is protected by two jetties, a north jetty and south jetty.
The U.S. Army Corps of Engineers (USACE) constructed and maintains the two jetties for the purpose of providing reliable navigation into and out of the bay. Proposed repairs to the north jetty include toe, side slope, and crest repair construction above -10 feet NAVD88 elevation along 1,300 feet of the jetty trunk/root. This trunk/root section will be constructed with a crest width of 30 feet, side slopes of 1V:2H, and a crest elevation of +22 feet NAVD88.
The estimated stone volume required for the north jetty repairs is approximately 8,970 cubic yards with a minimum stone density of 167 pounds per cubic foot.
Optional work includes repairs to 400 feet of jetty root to a crest width of 20 feet, 1V:2H side slopes, and crest elevation of +18 feet NAVD88.
The estimated stone volume for the optional repairs is 3,830 cubic yards with a minimum density of 167 pounds per cubic foot.