| The May 18, 1980, eruption of Mount St. Helens generated a lateral blast, lahars, and tephra deposits that altered the tributary channels in the Lewis River drainage basin. In order to assess potential flood hazards, study channel adjustments, and construct a sediment budget for the perturbed drainages on the northeast, east, and southeast flanks of the volcano, channel cross sections were monumented and surveyed on Pine Creek, Muddy River, and Smith Creek during September and October of 1980. Additional cross sections were monumented on Swift Creek, Bean Creek, and Clearwater Creek during the summer of 1981. This report presents plots of channel cross-section profiles, longitudinal stream profiles, and channel planform maps constructed from the survey data collected during water years 1983-84. -- Martinson, et.al., 1986 |
