? deforestation in the watershed
? the Tillamook Burns of 1933, 1939, 1945, and 1951
? land use practices in the watershed, including road construction, agriculture, and urbanization
The greatest impacts of these sources of sedimentation probably occurred prior to the 1957 bathymetric survey. In addition, the bay has been altered in a variety of other ways that have undoubtedly affected its bathymetry. These include the drainage of wetlands and construction of dikes and levees. The inlet from the ocean was modified by constructing jetties, and dredging of navigation channels has occurred throughout this century (Percy et al. 1974). The most catastrophic change occurred in 1952 when the spit was breached just north of the current location of Cape Meares Lake. This may have been due to erosion of Bayocean spit in response to construction of the north jetty. The breach remained open until a dike was constructed in 1956 to close it off.
BATHPT95.PAT COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC 1 AREA 4 12 F 3 5 PERIMETER 4 12 F 3 9 BATHPT95# 4 5 B - 13 BATHPT95-ID 4 5 B - 17 DEPTH 8 8 F 2 25 NEAR50 1 1 I - 26 ADJ-MLL 4 12 F 3