Mount St. Helens Recovery |
Common terms and phrases
258 million cubic Area Maximum asked the Corps August 19 avalanche basins Blast Castle Rock cause flooding Coldwater creek Coldwater Lake Columbia River conduits construction begins coordination Corps planners Cowlitz River Crest Height Crest Width cutterhead Dam Crest debris dam Decision Document deer and elk downstream earthquake embankment emergency erosion eruption of Mount excavated feet FEMA flood protection flow of water Fork Toutle river fully restored gravel Green River Helens recovery hopper dredges Kelso knowledge and expertise lake level levees Long-Term Solution Longview March 20 miles million cubic yards mole MOSSYROCK Mount St mountain mud and debris mudflows NGVD north face North Fork Toutle November outlet channels outlet pipe Pipeline dredge post-eruption streambed Pumping response retain sediment retaining structures Ridge river channels Sediment Retention Structure Shipping channel solid rock South Coldwater Spillway Crest Spirit Lake SRS construction structures built temporary structure trailing gear Tunnel construction upper Toutle River Volcanic material winter