142 NAUTICAL CHART MANUAL 



CHANNEL DEPTHS 



The project depth in the channels of the Columbia and Willamette 

 Rivers are. 48 feet from the entrance to Clatsop Spit Lighted Whistle 

 Buoy 14, thence 35 feet to Portland. Oregon, and 30 feet from the mouth 

 of the Willamette River to Vancouver. Washington. 



Freshets occur annually during the months of May. June, and July 

 which may cause some shoaling; however, channels are restored to 

 project depth as soon thereafter as possible. 



The controlling depths are published monthly in the local Notice to 

 Mariners by the U.S. Coast Guard and monthly in the U.S. Naval Ocean- 

 ographic Office Notice to Mariners. Additional information may be obtained 

 from the Corps of Engineers. U. S. Army. Portland. Oregon 



6152 



WIRE DRAGGED AREAS 



The area tinted green has been swept by wire drag to a depth which 



in deep waters materially exceeds the draft of the largest vessels. 



In shoal waters the drag was set to pass as close as practicable to 



the bottom. 



8094 



(Green overprint) 



Information blocked out in green is 

 now obsolete. Corrections in green to 

 Oct. 30, 1950. 



(Green overprint) 



FIGURE 11— Standard Notes 



