149 



Snak* RIvtr Spill 



The results of spill 



Spill has counteracting effects: 



• (+) Fish survival in spill passage is higher than in turbine passage. 

 •(-) Spill increases gas supersaturation in tailwaters and reservoirs. 



• (-) Gas supersaturation in water kills fish downstream of dams. 



• (-/+) Spill at transport dams lessens the fraction of fish transported, 



which, under current assumptions of transportation, lessens total 

 survival. 



100 



110 120 130 



Nitrogen Saturation {%) 



CRiSP-predicted survivals with spill-produced gas levels 



The dashed line indicates forebay and tailrace gas levels allowed 

 in the NMFS spill plan. The solid lines indicate the range of total 

 dissolved gas below Ice Harbor Dam in the 1995 spill program. 



Jam»( Arvl«r«on 



Unfversity of Washington 



Juno 22. 1395 



