Ponds and Lakes with Excavated Basins 25 



that would not survive if placed in one large pond containing other more 

 aggressive fishes. However, no pond should have an area of much less 

 than one acre; otherwise, it \\ ill be too small for satisfactory fishing. 



The standing crop of fish supported by gravel pits may be lower than 

 that of artificial ponds receiving direct surface runoff from farm lands, 



Figure 2.3. Gravel-pit ponds planned for recreational uses 

 after gravel removal. Current gravel-removal operations were 

 confined to the long narrow ponds in the pit area at the upper 

 left. Bodies of water were kept separated and stocked with 

 various combinations of fish, so that each pond could be easily 

 renovated if fishing became poor. The square pond at the upper 

 left is about 4 acres; a bathing beach and diving pier were 

 built at its lower left corner. 



but the fish-population size (weight) is related to the fertility of the 

 surrounding land, in spite of the fact that there may be no direct surface 

 runoff into the gravel-pit ponds. 



The water level in a gravel-pit pond is that of the water-table level 

 because the sand-bottomed basin will not hold water. This may be 



