The difference in mineral content indisate that sand moves around 

 Point Conception and Point Arguelo, As the streams have not been in 

 major flood for a number of years, it follows that most of the 900 

 cubic yards of sand a day that is trapped in Santa Barbara comes from 

 off shore areas or littoral drift from the north. 



5. A report by Parker Do Trask entitled "Stationary Dredge for 

 By-passing Sand at Salina Cruz Harbor, Isthmus of Tehuantepec, Mexico," 

 was submitted to the Beach Erosion Board on 29 January. This report 

 was based upon an inspection of the project in November 1951 • The pro- 

 ject was described in the Bulletin of 1 July 1951 t The following ab- 

 stract from Mr. Trask 's report contains additional data on the operation 

 of the project, 



atationary Dredss £qv By^Paiiina Sand at 



Salina Orua is losatid in a iatting of great beauty on a imall 

 flat surrounded by hills on the Pacific coast of Southern Mexico. 

 The harbor is entirely artificial, though a small lagoon evidently 

 existed in the a rea at time of the construction. The two breakwaters 

 that form the harbor are 4-, 000 feet in length, 700 feet apart at the 

 entrance to the harbor and 3,500 feet apart at the rear of the harbor 

 (Figure 1). These breakwaters are 18 feet wide on top and an equal 

 height above mean low water. Massive granite riprap composed of blocks, 

 8 or more feet in diameter effectively protects the breakwaters from the 

 waves, A transverse dock s\ipplied with roadways and railroad tracks 

 divides the harbor into an outer and an inner port, Entrance to the 

 inner port is made through a bascule drawbridge » The harbor is modem 

 up' to date in every respect, and is very efficiently managed. 



The harbor and railrcad across the Isthmus of Tehuantepec were 

 constructed and placed in operation prior to the completion of the 

 Panama Canal, In time sand, moving toward the east, filled the area 

 between the breakwater and the headland to the west. Subsequent to 

 1910 the sand is reported to have drifted across the mouth of the 

 harbor, effectively closing it to shipping. This sand Tras later re- 

 moved, and the harbor dredged to a reported depth of 4-0 feet. As 

 of November 1951 the harbor is said to have shoaled in places to 30 

 feet. 



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