16 Fish and Game Warden. [Bull. No. 1. 



cases it is a good idea to remove the loose rocks for a distance 

 of several yards or rods above the dam and cover the area 

 from one to two feet in depth with well-packed clay or good 

 hardpan soil. 



I am also informed by men who have had experience that 

 it is not a good idea to pile rocks in with the dirt that forms the 

 dike or dam. Better keep the rocks if they are present to rip- 

 rap the banks after the dam is finished. Good results have 

 been secured where sandy or boggy places have been met with 

 in foundations by digging one or two ditches from sixteen to 

 twenty-four inches deep (or deeper if need be to get to and 

 down six or eight inches into solid clay or hardpan) and from 

 three to six feet wide through the entire length of the founda- 

 tion of the dam. (See figure 2.) These ditches should be 

 filled with good dirt, as free as possible from grass and plant 

 roots. The dirt should be well packed in the ditches by being 

 tramped by the animals that pull the scrapers. 



Size and Width of Foundation. 



As indicated above, all sand and gravel beds and all trash 

 such as decaying vegetation, including plant roots, old logs 

 and stumps, as well as loose rocks, should be removed and in 

 no way get mixed up with the earth that forms the foundation 

 of the dam. Chunks of sod that may be plowed up in shaping 

 the bottom of the pond should not be used in the earthworks, 

 at least of the lower half of the dam. They can better be 

 placed near the top of the earth structure or for riprapping 

 the sides of the dam or for sodding the completed structure. 

 If the foundation of the dam is to be forty feet wide in the 

 center when completed, it should by all means be started at 

 that width. Never start a foundation at twenty feet and then 

 allow the dirt to roll down the sides of the structure until it is 

 forty feet wide. Such work leaves too much loose, unpacked 

 earth on the outside of the embankment that is easily washed 

 away by rains and waves. 



While the dam is being built the dirt should be spread over 

 the top or surface of the growing structure in such a way as 

 to keep it comparatively level, and it should be tramped with 

 the teams as evenly as possible to prevent uneven settling that 

 would leave high and low places on the surface of the finished 

 dam. 



The width of the foundation or the base of the dike or dam 

 depends, of course, upon the proposed height of the structure. 

 For every foot in height there should be not less than from IV2 

 to 2 feet of slope to the sides. For a dam 12 feet high and 'from 

 8 to 12 feet wide at the top — wide enough for a good wagon 

 roadway — the following proportions should be observed (see 

 cut, figure 3, showing cross-section of pond and dam) : On 

 the water side of the dam, the slope should be, as shown in 

 figure 3, not less than 2 feet in width for every foot of height. 



