"The 1980 eruption of Mount St. Helens in southwest Washington State radically changed the physical and socio-economic landscapes of the region. The eruption destroyed the summit of the volcano, sending large amounts of debris into the North Fork Toutle River, and blocking the sole means of drainage from Spirit Lake 4 miles north of Mount St. Helens. As a result of the blockage, rising lake levels could cause failure of the debris blockage, putting the downstream population of approximately 50,000 at risk of catastrophic flooding and mud flows. Further, continued transport of sediment to the river from volcanic debris deposits surrounding the mountain reduces the flood carrying capacity of downstream river channels and leaves the population vulnerable to chronic flooding. he legacy of the 1980 eruption and the prospect of future volcanic, seismic, and flood events mean that risk management in the Spirit Lake Toutle River system will be
| ISBN: | 9780309464444 |
| Publication date: | 29th March 2018 |
| Author: | Committee on LongTerm Management of the Spirit LakeToutle River System in Southwest Washington, National Research Council US, Engineering, and Medicine US National Academies of Sciences, Engineering, |
| Publisher: | The National Academies Press |
| Format: | Book |
| Series: | Consensus Study Report |
| Genres: |
Pollution and threats to the environment |