IIAICHKin RKUriRKMF.NTS 



35 



Table 4. continued. 



ITEM 



HATCHERY 

 SYMBOL 



CRI 1 KRIA 



Water supply [continued) 

 Availability T 



Turbidity T 



Supply lines 



Siie T 



Type 



C 



c 

 c 



Floor slope T C 



Intake control T C 



W Gravity or artesian flow preferred. 



Clear. 

 W Clear or only slightly turbid. 



Adequate to carry Ij times quantity of water 

 required. Consider future hatchery expan- 

 sion when sizing supply lines. 



W Main supply lines adequate to fill 1-acre pond 



in 2 days and all ponds in 14 days or less. 



W Cast iron, concrete, or steel, unless size or soil 



conditions make other materials desirable. 

 Teflon, nylon, or other proven, durable inert 

 substances are acceptable. Under no condi- 

 tions should copper, brass, or zinc galvan- 

 ized pipe be used. 



RacewaNS and circular pools. 

 W Earthen ponds. 



Rectangular raceways: 8' x 80' x 30" or 

 6' X 60' X 18"; Burrows recirculation ponds: 

 17' X 7.5' X 3'; Swedish-type ponds: 



3f)' X 36'; circular ponds: varying from 6 to 

 50 feet diameter, concrete or fiberglass con- 

 struction. 

 W Earthen ponds: 0.75 to 1.0 acre preferred; 1 to 



4 acres allowable; 0.1 to 0.5 acre for special 

 purposes. Minimum depth of 3 feet at shal- 

 low end, (i feet at deep end for rearing 

 ponds. Deeper ponds (10-12 feet) may be 

 desirable in northern areas, and for channel 

 catfish rearing regardless of climate. A 2:1 

 slope is standard with riprap on sides and 

 3:1 slope without riprap. Dyke tops should 

 be 12 feet wide with gravel surface. Core 

 wall mandatory. Seed banks to grass. 



0.6" to 1.0" in 10', except bottom of recircula- 

 tion ponds, which should be level. 



Headbox with concrete overflow wall and 

 adjustable metal weir plate control for indi- 

 vidual raceways, or pipe discharging above 

 the pond water surface; inlet should be full 

 width of raceway. 

 W Cast iron pipe with shutoff valve for take-off 



to ponds. It may be desirable to have two 

 supplies: the main suppl> at the outlet to 



