3() KISH HAICUKKV MANAGEMENT 



Table 4. continued. 



ITEM 



HATCHERY 

 SYMBOL 



CRH ERIA 



Rearing facilities {continued) 



Outlet control T 



Screen slots 



Freeboard 



Water changes T C 



Arrangement T C 



Electric lines 



Screens 

 Walks 



T 

 T 



C 

 C 



provide fresh water in the catch basin when 

 pond is harvested; and a supplemental sup- 

 ply at the opposite end from the outlet 

 structure. The supplies should enter the 

 pond above the water surface or not lower 

 than the top of the drain structure. 

 Overflow full width of raceway, with standpipe 

 or valve that is tamperproof. 



W Standard plans are available, and may be 



modified to include concrete baffle and 

 valve where pumping is necessary. Struc- 

 tures located in the bank should have ade- 

 quate wing-walls to prevent sloughing of 

 embankments. Outside catch basins should 

 be used where practicable and serve as many 

 ponds as feasible. Provide steps and walk- 

 way around the catch basin. A minimum of 

 10"'ii slope in pipeline from the pond kettles 

 to the outside catch basin is required. Out- 

 side catch basins must have a fresh water 

 supply available. Kettle chimneys should 

 have 1" X 3" key way for safety covers. 



W Double slots in walls and floor at drain end, 



either 2-inch double angle or 2-inch channel 

 of noncorrosive metal. 

 6-12 inches in raceways, pools. 



W In earthen ponds, 18 inches is sufficient. 



Ponds should be oriented to limit sweep of 

 prevailing winds. 



W Minimum of 3 per hour, except one for Bur- 



rows recirculation ponds. 



W Double in series or in rows. Provide 14 feet or 



wider driveways between series. Allow suffi- 

 cient fall between series for aeration; 18-24 

 inches is recommended, up to 14 feet is 

 acceptable. 



W To be laid at the time of construction either in 



raceway walls or alongside with outlets 

 spaced to satisfy operational requirements. 

 Consider automatic feeder installations, 

 floodlights, raceway covers, etc. 



W Perforated noncorrosive metal. 



W 14-16-inch concrete walkways, broom finish; 



aluminum skid-proof grating. For safety all 

 open flumes, control structures, etc., should 

 be covered with nonslip grating. 



