Streams
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- Logs formed pools, slowing stream flow in some sections and accelerated flow in others. [four years after eruption]
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- Changes in stream characteristics were determined by repeated surveys. [2 years after eruption]
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- Scientists observed how logs influence stream structure, especially the formation of pools and riffles.
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- In other sections, all logs were removed from the stream while in other sections only a partial removal was conducted.
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- In some sections of Clearwater Creek all logs were left in place in the stream. [1 year after eruption]
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- Scientists and forest managers installed a long-term experiment to study the role of logs in streams. [3 years after eruption]
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- Erosion washed pumice and ash off adjacent hillsides and into streams. [1 year after eruption]
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- Blast zone streams were filled with downed trees. [1 year after eruption]
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- Small tributary streams were a key place for early establishment.
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- Streams and wetlands fed by groundwater springs are stable and willows and Sitka alders are taking root. [29 years after eruption]
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- The boulder-filled mudlfows scoured stream channels uprooting and depositing trees downstream.
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- Logs were washed downstream and deposited along channels.
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- Trees were swept away and washed downstream.
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- Damage was limited to the valleys in which the lahars were channeled downstream.
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- In time, streams are gradually returning to pre-eruption conditions
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- As streamside vegetation develops, streams begin to be shaded once again.
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- As streambeds cleared, abundant cobbles and algae provided excellent habitat.
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- Temperatures were higher in blast zone streams.
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- Formely forested streams were transformed into open, sediment-rich waterways. [2 years after eruption]
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- Eroded blast deposits were washed downstream. [3 months after eruption]
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- Habitat conditions in streams were profoundly alterred. [3 months after eruption]
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- Surviving roots sprouted from eroded streambanks
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- Transport of sediment downstream was a mjor concern.
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- Downed trees trapped sediment.
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- Logs helped stabilize streambeds, forming riffles and pools to the benefit of habitat for fish,
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- Following the eruption, streams were filled with ash eroded from blast zone hill slopes.
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- Surviving roots sprouted from exposed soil on stream banks.
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- The lahars formed cement-like slurries that swept trees, log-decks and logging equipment downstream.
