MODIFICATIONS OF A TURBULENT FOUNTAIN FOR USE AS A FISH 

 SCREEN IN SMALL HIGH GRADIENT STREAMS 



Abstract 



We tested the efficacy of a modified turbulent fountain for its ability to screen fish 

 from an irrigation diversion in McCabe Creek, Montana. We released westslope 

 cutthroat trout {Onchorynchus clarki lewisi) into the intake of a prototype fountain in 

 order to field-test screening capability and impingement rates. We then corrected 

 observed flaws in the screen and repeated the test to compare efficacy of the prototype to 

 the modified, more "fish-friendly" design. Fish lengths were similar between the two 

 tests. Following modification of the prototype screen, the number of impinged fish 

 declined from 37% to six percent. The duration of impingement declined by 93%, from a 

 median of 30 seconds to two seconds. This evaluation indicates that turbulent fountain 

 screens, when designed and constructed with proper fisheries considerations, can be 

 effective at screening fish, and provide a low-maintenance, more practical alternative to 

 traditional fish irrigation screening devices on small streams. 



Key Words: turbulent fountain, irrigation diversion, impingement, fish screen, native fish 

 recovery. 



From: Pierce, R. W., R. J. Krogstad and G. A. Neudecker. 2003. Modifications of a 

 turbulent fountain for use as a fish screen in small high gradient streams. Intermountain 

 Journal of Sciences, Volume 9(4). 



85 



