Rattlesnake Canyon

Jun 01, 2009

RAY: This was sent in by Russell Howe and it's from my inland streams and waterways series. Russell writes:

"I live in Santa Barbara, California, and in late August, I was with a group of people who were taking a guided hike through Rattlesnake Canyon.

"The rattlesnake population in Rattlesnake Canyon is one rattlesnake per nine acres. We crossed a stream that was obviously low. The rainy season in Santa Barbara begins in November and no rain had come to the area since the previous April. So May, June, July and now August, no rain.

"The guide told us that every fall, just prior to the start of the rainy season, the stream level rises. She wondered why and did some checking. Was it because rain had occurred in some distant place and the off-flow had finally made its way to the stream? No.

"Was it because someone upstream, like maybe a factory that had been using water for whatever purpose, stopped using it? No.

"Was a dam opened up or did something like that occur?"

What could possibly explain why the water level would rise prior to the start of the rainy season?
RAY: Here's the answer. Upstream there are trees that take carbon dioxide from the air and make oxygen out of it. That greenery is using up water to make leaves and do that process of photosynthesis.

Well, by the time November rolls around, the trees and all the other shrubs that are growing by the stream have begun to go into dormancy. The leaves change color, they fall off the trees, and the need for water diminishes considerably so they're not sucking water out of the stream. Then, even though there's no rain--the level what?

TOM: Goes up.

RAY: There you go. Do we have a winner?

TOM: Yes. The winner is Susan Cady from Morrison, Missouri. And for having her answer selected at random from among all the correct answers that we got, Susan's going to get a $26 gift certificate to the Shameless Commerce Division at cartalk.com, with which she can get something for her father for Father's Day.

RAY: Yeah, and you know if your father's kind of a pain in the butt, you can get him a copy of our CD, Why You Should Never Listen to Your Father When It Comes to Cars. Once he gets that he might ignore you for weeks. Congratulations, Susan!

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