SEA-WATER SYSTEM OF THE MARINE LABORATORY 

 OF THE UNIVERSITY OF CALIFORNIA, 

 SANTA BARBARA 



By Donald K. Joicc, OFfice of Architects and Engineers, 

 and Demorest Davenport, Department of Biological Sciences, 

 University of California, Santa Barbara, Calif. 



Abstract. — The sea-water intake system of the Marine Laboratory of the University 

 of California, Santa Barbara, lies in the tidal zone of the campus beach. The 48-square- 

 foot filter, a concrete box filled, with graded aggregates and having a perforated collection 

 header at the bottom, is located at low-tide level. The filtered water is carried to the lab- 

 oratory through a buried pipe under the suction of a shore-based jet pump. As a cleaning 

 device, the surf's constant agitation of the beach sand over the filter has contributed to 

 giving an uninterrupted, maintenance-free service of 35 gallons per minute for over 4 years. 



The sea-water system of the Marine 

 Laboratory on the campus of the Uni- 

 versity of California, Santa Barbara, is 

 made up of three basic components: a 

 sand fiker intake unit located in the surf 

 approximately 400 feet from the shoreline, 

 a jet-type pump assembly, and a reservoir 

 head tank combination located on shore 

 near the laboratory. 



The filter unit has been in operation al- 

 most continuously for 4 years without any 

 malfunction, or any maintenance. The 

 pumping portion of the system has re- 

 quired only the type of maintenance and 

 replacement program normal to any 

 pumping plant. 



This paper will deal primarily with the 

 sea- water intake unit, which is the critical 

 component of the system. Figure 1 shows 

 the relations of the three components. 



The physical characteristics of the cam- 

 pus beach placed certain limitations on the 

 installation. The beach floor is of an im- 

 permeable but relatively soft monolithic 

 shale which is known to be over a thousand 

 feet deep. This shale, with a surface 

 elevation of 1.5 feet at the shoreline, tapers 



off slightly over a foot in 400 feet. From 

 this point it slopes off at a more acute 

 angle, dropping approximately 3 feet in 

 the next 100 feet. In certain winter 

 months the wind and tides clear virtually 

 all sand from the shale leaving it as barren 

 as a table. At such periods the surf comes 

 within a few feet of the shoreline. During 

 the summer months tidal action redeposits 

 the sand on the beach to a depth of from 

 2 to 6 feet. During these periods the surf 

 will be lield out as much as 400 feet from 

 the shoreline. 



The intake filter unit is a flat reinf orced- 

 concrete box (fig. 1), with 6-inch walls and 

 bottom, 6 feet by 8 feet by 21/2 feet inside 

 dimensions. A header made up of 4-inch 

 cast-iron bell-and-spigot crosses runs the 

 length of the box at the bottom. Ten cast- 

 iron perforated laterals, 2 inches in di- 

 ameter, are lead-caulked into the header. 

 The box is filled with graded aggregate to 

 form the filter, the purpose of which is to 

 screen out sand and flotsam. 



The filter unit is buried in the floor of the 

 beach, the top being approximately level 

 with the shale floor at elevation — 1.5. The 



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