THE GAME BREEDER 



77 



earthen embankment connecting them 

 will complete the inclosure. Such loca- 

 tions must be surrounded by ditches to 

 divert surface water where that is likely 

 to roil the pond, and effective waste 

 channels should be provided if the site 

 covers the natural course of flood 

 waters. 



If fiat land of an elevation only slight- 

 ly lower than that of the source of water 

 supply is selected, it will be necessary 

 to excavate the ponds in whole or in 

 part to the required depth to insure a 

 water level lower than the supply. Thus 

 the excavations will form solid banks 

 which, if impervious to water and prop- 

 erly sloped, will require no further at- 

 tention except to bring them to uniform 

 widths and elevation, which can be done 

 with the material excavated in forming 

 the pond proper. The bottom of the 

 pond should be shaped to drain to a 

 central point. 



On swamp lands and depressions 

 which are susceptible to drainage- and 

 are at the same time low enough to 

 insure a gravity flow of water from the 

 source of supply, one or more fish ponds 

 can be constructed by the erection of 

 longitudinal and cross-section dikes high 

 enough to provide the required depth 

 of water. The construction of such 

 ponds involves only sufficient excavating 

 to give the bottom the proper slope. In 

 other words, the pond should be built up 

 rather than excavated, and the water 

 level therein will be higher than the sur- 

 rounding land. 



The method of constructing pond em- 

 bankments is governed by the topo- 

 graphy of the land, the character of the 

 soil, and the volume and pressure of the 

 water to be confined. All made embank- 

 ments should be at least 6 feet wide at 

 the top, and the sides sloped not less 

 than 2 feet to each foot in height. For 

 instance, a 6- foot fill should be 30 feet 

 wide at the base and 6 feet at the top. 

 _ Prepare the foundation by plowing the 

 site of the embankment, after first re- 

 moving all trees, underbrush, rock and 

 sod, and, as an extra precaution against 

 seepage, dig a trench 12 inches deep 

 along the median line. This will form 



a break, or set-off, between the original 

 ground and the made construction, which 

 is a point of natural weakness. The fill- 

 ing should progress by layers over the 

 full width and length of the levee as ^ 

 continuous operation rather than by sec 

 tions ; otherwise the completed work will 

 later develop checks by reason of varia- 

 tions in material and compactness. Rocks 

 are of use as a protecting riprap on the 

 slopes after completion. 



In case the water supply to a pond is 

 taken from a creek, the latter must be 

 dammed and an intake built above the 

 construction provided with screens and 

 dam boards, from which a water conduit 

 must be laid to the pond. The dam 

 should be provided with an ample spill- 

 way, which may best be constructed of 

 concrete. 



The shape or outline of the pond is 

 immaterial. Currents of water are un- 

 desirable in the propagation of the spiny- 

 rayed fishes. In fact, the best brood and 

 rearing ponds are those which are sup- 

 plied by backwater from other bodies, 

 and if there is reasonable depth and a 

 fair growth of vegetation no stagnation! 

 will result. 



Success in pond fish culture is being 

 attained with widely varying forms of 

 construction. To a considerable extent 

 fish will adapt themselves to existing 

 physical conditions. In nature they seek 

 comparatively shoal waters in which to 

 spawn, by reason of the prevailing high- 

 er temperatures, and during certaip 

 stages of their growth the young choose 

 similar depths, where food is plentiful 

 and beyond the bounds of the customary 

 range of large fish. Relatively deep 

 waters must be accessible to the stock 

 fish during winter months, and what this 

 depth shall be will depend largely upon 

 the latitude of the location ; cold climates 

 where great thickness of ice forms re- 

 quire the deepest pools. 



Experience teaches that breeding 

 ponds should be excavated to hold not 

 less than 12 inches of water at or near 

 the margins ; that one-fourth of the pond 

 area should range from 12 to 30 inches 

 in depth ; and that one-half its total area 

 should be not over 3 feet deep, the hot- 



