WEBVTT

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This is a cutout view of a river.

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The dark blue water is water that flows

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into the drainage system behind the dams.

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The light blue water is water that flows

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into the system from uncontrolled

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rivers and streams.

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When the rains come and the uncontrolled

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streams fill the Willamette's system,

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the Corps holds water behind the dams.

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As the river level drops,

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the Corps releases the water into the system.

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Every dam has at least two ways to release water.

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Some, like this dam at Lookout Point, have three.

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For dams that generate electricity,

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water passes through the powerhouse

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and into the river below the dam.

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The second option at Lookout Point

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– and the primary route

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for dams without powerhouses-

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is the regulating outlet.

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This is a gated route through the dam itself.

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The spillway gates, near the top of the dam,

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are used to move water through the dams

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when other routes are unavailable

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or when the reservoir gets too full.

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These gates are always a back-up system

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and are not used very often-or even every year.