b. A relatively long and narrow shape aligned longitudinally in 

 the floodplain and providing an irregular configuration with 

 islands and peninsulas is preferable (Figure 16a and 16b) 



• Islands and low peninsulas provide more diverse shoreline 

 and aquatic habitats 



• If the river does divert through the pit, it will have an 

 alignment to follow and will more quickly develop into a 

 channel configuration 



c. An outlet channel for a path of low resistance when the pit is 

 inundated, reducing erosion of undisturbed terrestrial habitat. 

 An outlet channel also provides an avenue of escape for fish 

 which may become trapped during high flows. 



• Outlet channels should be deep enough to allow fish passage 

 during low flow conditions and be as narrow as possible 



• All outlet channels should be on the downstream end of the 

 pit to prevent premature degradation of the stream channel 

 and p i t 



• Outlet channels should be connected to a non-depos i t i ona I 

 area of an active channel and be angled downstream 



• Outlet channels should not be of straight line configuration 



• Outlet channels should be constructed at the end of the 

 site closure to minimize siltation in the river 



d. A diversity of water depths and bank slope 



• At least 30 to 50 percent of the shoreline should have a 

 gradual slope to provide areas for emergent aquatic vegeta- 



71 



VI . SITE OPERATION 



