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<br />and compare the lake <br />bottoms now to the shape <br />ofthe pre-dam canyons. <br />Such work has not yet been <br />undertaken (Dennis <br />Womack, Idaho Power <br />Company, oral commun.. <br />1993). <br />Or one could examine <br />beaches along the Snake <br />River below Hells Canyon <br />Dam. Paul Grams (1991) <br />did just that by comparing <br />five sets of aerial photos of <br />the canyon taken at inter- <br />vals between 1955 and <br />1982. He found that the <br />surface area of beaches in <br />Hells Canyon had shrunk by <br />75 percent. Beaches <br />between Hells Canyon <br />Dam and the confiuence of <br />the Salmon were most <br />heavily degraded; the <br />Salmon appears to be reintroducing enough sediment to stabilize beaches below its <br />confiuence with the Snake. The greatest losses to beaches within Hells Canyon occurred <br />from 1970 through 1973. But Brownlee Dam had been completed in 1958 and Hells <br />Canyon Dam in 1967. Why didn't beach degradation begin immediately after closure? <br />Grams concluded it had taken that long to fiush enough sediment from the bed of the river <br />before beach degradation could begin in earnest. As long as some critical amount of <br />sediment remained in the system. fioods continued to deposit as well as erode beaches. <br />But once a river bed is stripped of sand, fioods can take what little is left of the beaches and <br />give nothing back. <br />Grams' study suggested that the beaches of Hells Canyon continue to shrink with <br />each passing fiood. but at a rate that has been decelerating since 1973. Does it matter? <br />River runners think so; with each passing fiood. they are more likely to be forced to camp <br />in rocky sites amidst the poison ivy off the river. as beach after beach gradually disappears, <br />How does one assign a value to the river runners' inconvenience? How does one com- <br />pare the value of landscape relative to society's need for energy. or Idaho Power <br />Company's responsibility to its customers and shareholders? Should something be done <br />just for the sake of preserving the ecosystem of Hells Canyon? After all, the Snake carries <br />the Wild and Scenic River designation and is within a National Recreation Area. But these <br />areas were designated in 1975. long after Idaho Power Company was licensed to build the <br />dams. <br />The Snake River below Hells Canyon Dam offers a classic example of degradation <br />immediately downstream from a dam. Williams and Wolman (1984) documented many <br /> <br /> <br />S nai(? !Rjver <br /> <br />,--~- <br />1 80,000 <br /> <br />Location 01 phorograpi<.: sites <br /> <br />150.000 <br /> <br />.1.1964 <br />1111973 <br />.. j97~;l!f <br />..1982 <br />...199.0 <br /> <br />'" <br />u <br />" <br />'" <br />" <br />~ <br />" <br />o <br />~.'.ii~ $_ <br />~-". ' <br />C2Y <br />6ft <br />E,;; <br />0; <br />V),; <br /> <br />~ <br />.0 <br />-0 <br />" <br />~ <br />V> <br /> <br />60.000 <br /> <br /> <br />'i3 <br />~ <br />~ <br />" <br />0- <br />~ <br />~ <br />~ <br /> <br />1 20.000 <br /> <br />90.000 <br /> <br />~ <br />'" <br />~ <br /> <br />30,000 <br /> <br />o <br />o <br /> <br />150 <br /> <br />180 <br /> <br />30 <br /> <br />60 90 120 <br />Snake River in Miles <br /> <br />Sandbars on the Snake River in Hells Conyon have been shrinldng since <br />monitoring was begun in 1964; the greatest deaease is dOQJmented <br />between photographs token in /964 and /973 (modified fram Grams, <br />/99/; Schmidt and others, /995). <br /> <br />25 <br />