Lowering islands and banks by removing gravel, even if maintained 

 above the existing water level, can result in reduced stability of channels 

 during high water. Material sites will then be inundated at least tempo- 

 rarily. Spreading water over a broader area reduces its velocity, causing 

 deposition of suspended and bed load materials. Some of this reduced vel- 

 ocity may function to replenish materials in the abandoned material site but 

 this process would probably require a longer period than would be expected 

 in a braided system. 



Spreading of water and reduction of velocity is conducive to changing 

 water temperatures during the open water season. Altered water temperatures 

 may influence the abundance and diversity of aquatic biota by altering the 

 amount of usable habitat for particular species. 



The reduced stability of the channels that could occur after site 

 closure could be detrimental to the establishment of permanent biotic popu- 

 lations, in particular, benthic organisms. In addition, entrapment of fish 

 in pockets and pools in the disturbed site may occur as water recedes into 

 the active channels following high-water conditions. 



The increased deposition of both suspended and bed load materials 

 could be detrimental to the establishment of benthic communities. Fine 

 materials would likely be deposited in these areas, thus changes in the 

 structure of benthic communities could be expected. These changes would be 

 from organisms adapted to coarse substrate to those able to exist on finer 

 less stable substrate. 



Changing channel configuration by removing islands, removing gravel 

 deposits from banks, and locally widening the active f I oodp I a i n will affect 

 the scenic quality of an area. This aesthetic effect was quite noticeable at 

 the Sinuk and Kavik River sites where care was not taken to preserve natural 

 contours and channel configurations. In addition, stockpiles and remnants of 

 diversion berms were left in place. The net effect of these conditions was 

 to form a major contrast with the natural conditions occurring both upstream 

 and downstream of the site. 



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