Cause of the flood


January 21, 2009 · Updated 10:15 AM 

  • 0
  • Print Story
  • Letter/Editor

A Monday, Jan. 12, article in a Seattle newspaper correctly identified rampant development as a major casue of the massive flooding. The effects go beyond those listed. In summary, those effects include:

• Removal of natural vegetation which would slow runoff

• Replacement of natural vegetation with impervious surfaces (this includes lawns, which form a heavy mat that sheds water)

• Filling in the floodplain

• Building barriers to the flow of water

• Building in the natural floodplain, which increases flood damage

These observations are based in part on my extensive study of the Nov. 1990 flooding in the Upper Snoqualmie Valley in a city-sponsored survey. Comparison of flow rates between Nov. 1990 and Jan. 2009 show that the flow from the Cascade range in Jan. 2009 was much less than in 1990, while the flow in the Valley (where all the development has taken place) was much greater.

Kenneth P. McCarty

Bellevue

Comment on this story.

COMMENTING RULES: We encourage an open exchange of ideas in our online community, but we ask you to follow our guidelines for respecting community standards. In a nutshell, don't say anything you wouldn't want your mother to read. Please see our FAQ if you have questions or concerns about using Facebook to comment.

So keep your comments:

  • Civil
  • Smart
  • On-topic
  • Free of profanity

We ask that all participants own their words by logging in with their Facebook account. It's a simple process that will take seconds and helps keep our comments free of trolls, cranks, and “drive-by” commenters. We reserve the right to remove comments from anyone using screen names, pseudonyms or false identities. Please refer to our Terms of Use for full detail on participating on our site.

blog comments powered by Disqus