28 



WATER TRANSPORTATION 





Sx---:;^^^' 



Small splash dam, seen from below, at the summer 

 camp of the Biltmore Forest School. 



Splash dam with the gate swung open 



Splash dams built in tributaries are 

 filled quickly enough. 



A system of dams of 

 first, second, and third im- 

 portance is frequently formed. 



The distance of effect- 

 iveness of a dam depends 

 on the size of the water re- 

 servoir, the width of the water 

 course below the dam, and 

 the rapidity of its fall. 



Splash dams meant to 

 be permanent must be built 

 of stone and are exceedingly 

 expensive. The Yellow Poplar 

 Lumber Co., of Coal Grove, 

 Ohio, have built a concrete 

 splash dam in West Virginia 

 at an expense, it is said, of 

 ^200,000. 



The usual splash dam 

 consists of timber cribs filled 

 with rock and joined by logs 

 laid crosswise. The front of 

 the dam must be slanting and 



preferable to dams in the main creek, provided that they can be 



11 thu midst of the splash. 



is covered with a double layer 

 of boards. The gateway of 

 the dain must allow of rapid 

 drawing (or opening) of the 

 basin. The gates are either 

 constructed barn doorfashion, 

 held in place by a strong key 

 and lever, or consist of pil- 

 ing, the individual piles to 

 be lifted by a crowbar or 

 drum. Half- moon -shaped 

 gates are used in the Lake 

 States and in the Adiron- 

 dacks. 



The smaller the water 

 supply and the greater the 

 pressure, the tighter must be 

 the gate. 



Frequently additional 

 small gates are made to give 

 a "fore -water," meant to 

 loosen the logs in the creek 

 below the dam. The actual 



