Part I.] 



Fish Ponds. 



15 



(See figure 1.) If there are sand, loamy or gravel pockets or 

 boggy spots in the ground chosen for the foundation, they 

 should be scooped out. 



Fig. 1. Foundation for dike or dam. This drawing shows excavation made by 

 plowing and harrowing ; the sod and surface soil has been removed and ground put in 

 shape for permanent foundation. 



I am told by those who have had experience that it is prac- 

 tically impossible to build an earth dam that will hold water 

 on a natural stone foundation. The dam may be good, but the 

 water will seep under it between the rocks and the earth or 

 through the natural cracks and veins that exist in the rocks. 

 If a dam is to be built in such a location, a trench should be dug 

 through the rocks deep enough to reach a solid rock founda- 

 tion. On this foundation that has been dug to and at least 

 a few inches into the solid rocks, a reenforced cement wall 

 should be constructed that would rise from one to two feet 

 above the surface of the natural rock foundation. Over this 

 cement wall an earth dam may be successfully built. In such 



Gpon^L/. boggy. 

 &0/7 or /oose loam 



^^^^^'"^^Blf^ 



mTTTTTTTTm. 

 C/cfLf or oY'her' /mpcr\/ioua nna-f-er/al 



Fig. 2. In spongy or boggy soil and loose loam, before starting to build 

 the dam, there should be a trench dug near the center and for the full length 

 of the dam. This trench should be about six feet wide, and deep enough to 

 extend into the clay or other impervious subsoil at least one foot. This ditch 

 should then be carefully filled with good clay or loam, free from stumps, 

 roots, twigs or other perishable material. In starting the dam on top of this 

 be careful not to leave a seam between the dam and the material in the 

 trench, but have the material thoroughly incorporated. 



mm^/^ 



Another form of Fig. 2, showing ditches in any ground where dike or dam 

 is to be built. 



