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What does the graph mean? Look
at one of the rain events (blue bars). After each rain event:
- Stream depth increases, due to water running off
the surrounding watershed. Stream depth will increase more in
urbanized watersheds (and will increase more quickly) because water
cannot infiltrate into soil covered with roads and parking lots.
- Turbidity increases. Sediments are washed from
the watershed into the stream. Loose sediments from construction projects,
roads, parking lots, and un-vegetated soils are carried into the streams.
- Conductivity (salt concentration) decreases. This
is because salts in the streams are diluted because the large volume
of water entering the stream during the storm dilutes the salts.
What does the graph mean? See
the explanation of the previous graph.
What does the graph mean? Look
at the snow event (blue bar). After the snow event:
- Stream depth remains about the same.
2.6 inches of snow is equivalent to only 0.2 inches of
water. Most of this "sticks" to the ground and
melts slowly, allowing it to infiltrate into the surrounding
soil.
- Turbidity remains low. Since snow "sticks" to
the ground, and melts slowly, it doesn't carry much sediment
to the stream.
- Conductivity (salt concentration) increases. The
salt that the city puts on roads to make driving easier
also ends up in the streams.
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