In a message dated 2/13/2006 7:13:43 A.M. Pacific Standard Time,  
[log in to unmask] writes:

http://www.ccrginc.com/#news 


Sean,
 
Various federal agencies erect mounds of natural rock to reduce the  velocity 
of downstream water and control otherwise raging rivers. I have never  heard 
the term "rock rollers," but have seen similar constructions built by the  
U.S. Forest Service, U.S. Army Corps of Engineers, California Division of  
Highways, and local agencies for diverting water, capturing sediments, create  
ponding, and just plain reducing speed to control the flow. I suggest you  contact 
the Army Corps of Engineers for their terminology and explanation of  when and 
why such a feature would need to be built.
 
Down here in San Diego County, enormous volumes of water run down from the  
mountains to inundate low desert communities. I have seen the County of San  
Diego, Department of Public Works build long piles of rocks at various angles to 
 break the speed of the flow and redirect it away from towns, ranches, and 
other  improvements. The California Department of Fish and Game also installed 
rock  mounds to impound water as habitat for fish and other aquatic species on 
some  drainages. A period when a lot of that kind of construction occurred was 
during  the Depression when work crews came cheap. They also built "water 
guzzlers" or  sheets of concrete that drained into shaft-like cisterns for 
animals to get  water (to improve nature's way of feeding the animals).
 
Ron May
Legacy 106, Inc.