24 Artificial Aquatic Habitats 



PONDS AND LAKES WITH EXCAVATED BASINS 



Although lake and pond basins can be completely excavated with 

 earth-moving equipment, this is infrequently done because of the high 

 cost. However, sometimes the clay needed for a pond dam may be re- 

 moved from the sides of the pond basin, so that the basin can be enlarged 

 and deepened in the process of building the dam. Also, ponds are some- 

 times dug or enlarged and deepened in real-estate developments or in 

 other special locations where cost is of secondary importance. 



On the other hand, there are many kinds of excavations made by man 

 that become filled with ground water and are eventually stocked with fish. 

 These "holes" are excavations for the removal of gravel, limstone, stone, 

 coal, or other near-surface mineral deposits. Some of these water-filled 

 pits are among the most attractive waters to be found south of the lake 

 states, because they are clear and quite infertile. Recent construction of 

 super-highways has resulted in many ponds where clay has been removed 

 to build grades for road overpasses. 



Gravel-pit Lakes 



Gravel deposits have been left by rivers from melting glaciers. Most 

 of these deposits, although covered with soils, are readily relocated by 

 test borings in regions where excavations ( such as well drillings ) or other 

 evidence have shown the presence of gravel. Since considerable gravel 

 is needed for road beds and as a component of concrete, this product is 

 in constant local demand. The sale of gravel, therefore, while not so 

 remunerative as that of most other minerals, furnishes more than enough 

 to pay for the cost of pond excavation. With a little planning, the excava- 

 tions left when operations are over, become attractive recreational waters. 



When digging is done primarily to develop recreational ponds (often 

 the case when gravel deposits are located under high-priced farm lands ) , 

 plans may be made for the arrangement of ponds, the leveling of the 

 spoil banks, and the respreading of the top soil over leveled areas in order 

 to greatly improve the pit area ( Figure 2.3 ) . In regions where lakes and 

 ponds are scarce, a well-planned recreational area superimposed on an 

 abandoned gravel works may bring a better price than the original farm 

 land, or, if strategically located and properly managed, produce annual 

 income equal to, or exceeding, the income from farm crops. 



A flooded gravel works may consist of a number of small ponds 

 separated by levees of sand or clay. Often when the pit owner decides to 

 develop the area for recreation, his first thought is to connect all of these 

 ponds. Yet, experience shows that several isolated ponds are more easily 

 managed for fishing than a single large one. Moreover, separated ponds 

 allow a greater variety of fishing because species can be stocked in some, 



