03-07-2008, 06:20 PM
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BUT the most beneficial flows will not come from midpoint in the river behind the dam, they would occur naturally along the entire length of the river channel if the lake didnt exist. By creating an artificial flow behind the dam, they are not simulating the natural flow of sediment, as they are not moving the majority of the sediment buildup from behind the dam,
I can't argue against this. You are correct. The MOST beneficial sediment flow would come from the upstream side of Glen Canyon dam. However, this isn't currently possible. So, we must rely on the next option -- using what's below.
This is where some are forgetting a few basic principals. We all know that there is very little sediment deposited directly below Glen Canyon Dam. However, this isn't where the scientists are hoping for the "scouring" and "sediment redistribution" to happen. As noted in previous posts, the Paria enters the Colorado near Lee's Ferry. There is a reason that the trout fishery suffers below Lee's Ferry -- poor water quality due to the Paria and it's sediment flows. The Little Colorado River just adds more. It is in these areas that the Humpback Chub, and other native species of the Colorado live. They don't live in the trout fishery section directly below the dam.
This is where the flooding will redistribute sediment deposits. This is where the area of concern is. Complaining about sediment load directly below the dam is concentrating on the wrong area of the river.
W2U is correct -- from the standpoint of a fishermen, we should all be happy with this "blow-out".
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BUT the most beneficial flows will not come from midpoint in the river behind the dam, they would occur naturally along the entire length of the river channel if the lake didnt exist. By creating an artificial flow behind the dam, they are not simulating the natural flow of sediment, as they are not moving the majority of the sediment buildup from behind the dam,
I can't argue against this. You are correct. The MOST beneficial sediment flow would come from the upstream side of Glen Canyon dam. However, this isn't currently possible. So, we must rely on the next option -- using what's below.
This is where some are forgetting a few basic principals. We all know that there is very little sediment deposited directly below Glen Canyon Dam. However, this isn't where the scientists are hoping for the "scouring" and "sediment redistribution" to happen. As noted in previous posts, the Paria enters the Colorado near Lee's Ferry. There is a reason that the trout fishery suffers below Lee's Ferry -- poor water quality due to the Paria and it's sediment flows. The Little Colorado River just adds more. It is in these areas that the Humpback Chub, and other native species of the Colorado live. They don't live in the trout fishery section directly below the dam.
This is where the flooding will redistribute sediment deposits. This is where the area of concern is. Complaining about sediment load directly below the dam is concentrating on the wrong area of the river.
W2U is correct -- from the standpoint of a fishermen, we should all be happy with this "blow-out".
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