548 



THE PANAMA KOUTE FOR A SHIP CANAL. 



After the coinpletion of all its exaiuiiiation.s, and after a careful 

 study of the data disclosed by them, the Commission deemed it advis- 

 able to plan such a dam as would cut ofi' absolutely all possible sub- 

 surface flow or seeimg'e through the sand and gravel below the river 

 surface. It is to be observed that such a subsurface flow might either 

 disturl) the sta))ility of an earth dam or endanger the water supply of 

 the sununit level of the canal, or both. The plan of dam finally 



Elev.-hlOO Top^f Dam>, 



Coffof Dam, 

 Work f 



• PneiUBatie CiJason Work 1314' 



'==z^ 



£leT.+'J2'Lake liobiu futl-^ 



Elcv. +0. Si-al.cv.l 



FiDtiSaiid, Gn 

 Little Cla; 



FiDe 6acid and Ulue CUf 



/ (Jisiel and Sand 

 ( Bloe Clay and ^Sand 

 I Coarse band 

 \ Sand and Cla; 

 Oravel, Sandv 

 Little Blue Cla; 

 Blue Cla; and ^aod 



Little Cla; ' 

 Sand and Blue Cla; 

 OrnielCrusta witb.^ 



(Vrllo» Cla; and Sand 

 Blue Cla; and Sand 



I Sand and Blue Cla; 



I Blue Cla; and Sand 

 Coarse Sand 



I Blue Cla; and Sand 



scaLe of feet 



—X- — -■ -I'MumjUtC Ciisscn \r6rk 



60 .100 200 300 

 5554' >v! — Coflfer Dam, Work 246- -J^ 34S-- 



'~J'^eW:7Z7P7yZ^7'Z7:7P;77777P^^^^7Zr7Z^^ 



I'rofilc (if Bohio dam site, selected fur plans and estimate, with section of dam. 



adopted by the Commission for the purposes of its estim'ates is shown 

 by the accompanying plans and sections. A heavy core wall of con- 

 crete masonry extends from bed rock across the entire geological 

 valley to the top of the structure, or to an elevation of 100 feet above 

 sea level, thus absolutely closing the entire valley against any possible 

 flow. The tliickness of this wall at the bottom is 30 feet, but at an 

 elevation of 30 feet below sea level its sides begfin to batter at such a 



