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VIEW A: Aerial view, Upper Muddy drainage, June 1980.
-- USGS Photo by Tom Casadevall, June 10, 1980

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VIEW B: Aerial view, Upper Muddy drainage, November 1981.
-- USGS Photo by Lyn Topinka, November 1, 1980

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VIEW A: Upper Muddy drainage, October 1980.
-- USGS Photo by Lyn Topinka, October 1980

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VIEW B: One year later - Upper Muddy drainage, October 1981.
-- USGS Photo by Lyn Topinka, October 1981

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One major problem to people living downstream of Mount St. Helens is the high sedimentation rates resulting from stream erosion of the volcanic deposits. Streams are continuously downcutting channels, eroding their banks, and eating away at the avalanche and lahar deposits. This material is eventually transported downstream and deposited on the streambeds, decreasing the carrying capacity of the channels and increasing the chances of floods.
-- USGS Photo by Lyn Topinka, February 22, 1982

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In order to remove the May 18, 1980 sediment deposits, and to keep up with new sedimentation, the U. S. Army Corps of Engineers began a dredging program on the Toutle (shown here), the Cowlitz, and the Columbia Rivers. By 1987, nearly 140 million cubic yards (110 million cubic meters) of material had been removed from the channels. This is enough material to build twelve lanes of highway, one-foot-thick, from New York to San Francisco.
-- USGS Photo by Lyn Topinka, February 5, 1981

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In the spring of 1987, construction of a sediment retention dam on the North Fork Toutle River began. This retention dam is designed to help stop the downstream movement of the sediment near where it begins - on the debris avalanche.
-- USGS Photo by Steven R. Brantley, May 1989

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River channel cross-section surveying - view here is of the North Fork Toutle River drainage, on north side of Mount St. Helens. Drainage has eroded into the blast deposits.
-- USGS Photo by Lyn Topinka

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River channel cross-section surveying - view here is at Pine Creek drainage, on south side of the volcano's base. Ash covers the ground surface. Mount St. Helens is in the distance.
-- USGS Photo by Lyn Topinka

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River channel cross-section surveying - view here is along the Muddy River drainage, approximately one mile (1.5 kilometers) southeast of the volcano's base. Rod person (lower left) and instrument persons (upper right) give scale.
-- USGS Photo by Lyn Topinka, June 26, 1981

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1983 - Looking upstream at the new Coal Banks Bridge across the Toutle River. The old bridge was destroyed on May 18, 1980.
-- USGS Photo by Lyn Topinka, April 4, 1983

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1987 - Looking upstream at the Coal Banks Bridge across the Toutle River.
-- USGS Photo by Lyn Topinka, February 24, 1987

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Aerial view, mouth of Pine Creek entering the Lewis River, with Pine Creek Bridge.
-- USGS Photo by Lyn Topinka, April 26, 1982

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Aerial view, looking upstream along the Muddy River, with Muddy River Bridge in foreground.
-- USGS Photo by Lyn Topinka, April 26, 1982

CVO Photo Archives - Hydrologic Monitoring

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