The Farm Fishpond 



2017 



The dike is continuous across the outlet except for a sluice near the top 

 to allow an overflow of excess water. 



All surfaces of the dike designated 

 by D are protected against erosion 

 by concrete or planking. In place 

 of the iron pipe and the gate valve, 

 sewer pipe may be used with an 

 elbow and a disk ])lug on the up- 

 stream end, similar to that described 

 for draining a pond above a dam 

 (Fig. 170, page 2012). 



Another inexpensive outlet and 

 drain combined (Fig. 178) consists of the following : Sewer pipe extends 



under the embankment, as de- 



FlG. I'j J. — Outlet for pond. A, dike; B, 

 overflow; C, cores; D, concrete walls; E, 

 apron; F, drainpipe; G, gate valve; II, 

 screen 





if^i 





TUllA 



mmmm 



>iiCT^ 



Fig. 178. — Outlet for pond. A, bottom of 

 pond; B, sewer pipe; C, dike; D, stand pipe 

 support; E, standpipe; F, water surface 



scribed, and in place of the disk 

 plug, two three-foot lengths of pipe 

 cemented together are loosely set 

 in the elbow. It is necessary to 

 select pipe and elbow that are 

 truly circular and to make the 

 joint as close fitting as possible with 

 cement. This vStandpipe will main- 

 tain a depth of water of a little 

 over six feet, and when it is desired 



to drain the pond, the standpipe is merely lifted out of the elbow. 



Making the pond water-tight 



A pond excavated in heavy clayey or loamy soil will seldom need special 

 treatment if the dikes are built compactly and care is taken to have them 

 fest on bare soil. If the soil is light and porous, however, puddling must 

 be resorted to. In certain cases where there is but little sand in the soil, 

 it may only be necessary to loosen the soil in the bottom of the pond 

 with a harrow as the water is first turned in, and, as the water level rises, 

 to continue harrowing around the margin of the pond, partly in and 

 partly out of water. This will roil the water, and the finer sediment 

 will be deposited in the pores of the subsoil. (See description of the Sam 

 Bailey pond, page 2018.) In the case of very porous soils of sand and 

 gravel, it may be necessary to draw in heavy soil and scatter it evenly 

 over the bottom. This should be stirred up when the water is turned 

 in until a very muddy condition results. Subsequent settling will usually 

 make the bottom impervious. 



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