Opinion ID: 453413
Heading Depth: 4
Heading Rank: 1

Heading: Impact of Road Construction on Water Quality

Text: 27 The draft and final EISs prepared for the Chimney Rock Section do address erosion and sedimentation effects of road construction on Blue Creek. The EISs state that total increased sedimentation would raise the sedimentation yield in Blue Creek by 5.5 percent, resulting in only a small decrease in water quality. The EISs do not, however, address increased sedimentation contributed by road-caused landslides, because of the difficulty inherent in predicting such slope failures. Thus, the potential risks to water quality stemming from the uncertainty in predicting landslides are ignored in the discussion of sedimentation effects. These risks must be revealed if they appear substantial. See State of Alaska v. Andrus, 580 F.2d 465, 473 (D.C.Cir.), vacated in part, 439 U.S. 922, 99 S.Ct. 303, 58 L.Ed.2d 315 (1978). 28 The district court found that landslide risks were substantial and that debris from landslides triggered by the road construction would result in as much as a 500% increase in sediment loads in Blue Creek. These findings are not clearly erroneous. The failure to disclose such risks in the EISs renders them inadequate. 29